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343 Cards in this Set
- Front
- Back
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What arteries make up cranial blood supply?
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2 Internal Carotid arteries
Basilar artery |
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What arteries make up spinal blood supply?
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1 anterior spinal artery (2/3)
2 posterior spinal arteries (1/3) |
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What is the normal oxygen consumption of the brain?
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3.5 ml O2 per 100g of brain weight
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What is the normal blood supply to the brain?
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50 ml/min per 100g of brain weight
15% of cardiac output |
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Cerebral autoregulation occurs between systolic pressures of _______________.
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50-150 mmHg
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What is the formula for central perfusion pressure (CPP)?
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CPP = MAP - ICP
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What is normal ICP?
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5-15 mmHg
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What 4 things determine ICP?
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Brain tissue
Spinal cord Blood CSF |
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What are some signs of increased ICP?
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Headache
Nausea & Vomiting Papilledema Depressed Consciousness/Coma |
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What is papilledema?
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Bulging of the optic disc
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What are some ways to decrease ICP?
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Elevate the head
Hyperventilation Drain CSF Vasoconstrictors Surgical decompression Hyperosmotic drugs |
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What are some examples of hyperosmotic drugs?
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Mannitol
Lasix |
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What are the risks of using hyperosmotic drugs?
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Hypokalemia
Dysrhythmias |
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What is the dose of Mannitol?
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0.25-0.5 g/kg over 15-30 min
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What are the determinants of CBF?
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CMRO2
CPP PaCO2 PaO2 |
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How does PaCO2 effect CBF?
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CBF increases 1 ml/100 g/min for every 1 mmHg increase in PaCO2
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When does PaO2 effect CBF?
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Below 50 mmHg (maximum dilation occurs to increase CBF) or above 150 mmHg (maximum constriction occurs to decrease CBF)
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What is ventriculostomy?
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Gold standard for measuring ICP and draining CSF
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What is the most common infratentorial tumor?
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Acoustic neuroma
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What are the contraindications for sitting position?
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VP shunt
Cardiac diseases Hydrocephalus Autonomic dysfunction Extremes of age |
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What do we need to remember about the blood pressure cuff in the sitting position?
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The cerebral blood flow is 2 mmHg lower for every inch of elevation above the cuff/heart.
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What are the risks of sitting position?
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Venous air embolism
Paradoxical air embolism Hypotension Ischemia of brainstem Obstruction Hematoma |
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What is a paradoxical air embolism?
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An air embolism caused by a patent foramen ovale
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In neurosurgery, what is it important to remember about the dosing of benzodiazepines?
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They have the potential to change the mental status which can confuse the neurological examination. Use them sparingly.
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Why is dexmedetomidine good for neurosurgery?
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It can induce sedation without respiratory depression
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Why do patients on anti-epileptics require more doses of neuromuscular blockers?
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Hepatic enzyme induction
Change in plasma binding Decreased ACh sensitivity Direct competition for binding sites |
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What is the major reason for neurosurgical procedures?
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Cerebral aneurysms
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Where do cerebral aneurysms often occur?
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Circle of Willis
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What are the complications of cerebral aneurysms?
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Re-bleeding (24 hrs after)
Cerebral vascular vasospasm (4-12 days after) Intracranial hypertension Hydrocephalus |
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What is triple-H?
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Treatment for cerebral aneurysm.
Hypervolemia, Hypertension, Hemodilution |
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What is the average blood loss for cerebral aneurysm surgery?
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250-1000 ml
2000-4000 ml with CPB |
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What is transsphenoidal surgery performed for?
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Pituitary gland tumors
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Which volatile agent is best for neuroanesthesia?
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Sevoflurane
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What is an arteriovenous malformation?
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Vessels that connect the arterial system to the venous system, bypassing normal arteriolar and capillary systems
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What are the common signs of AVMs?
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"Steal" syndrome/Ischemia
Seizures Hemorrhage |
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What is the intraoperative management for AVMs?
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Optimize perfusion
Decrease CMRO2 Decrease bleeding and treat blood loss |
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What are some reasons for awake craniotomy?
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Deep brain stimulation to treat Parkinson's, obesity, depression, OCD
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What anesthesia is useful for awake craniotomy?
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Dexmedetomidine and Propofol infusions together
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Who are interventional radiologists?
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Radiologists with specialty training in procedures that are percutaneous for therapeutic goals. They are not diagnostic.
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What are the benefits of general anesthesia for neurosurgery?
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Immobile patient for improved image quality and patient comfort
Better control of respiratory and hemodynamic profile |
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What are the benefits of sedation for neurosurgery?
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Patients are arousable and cooperative
Lack of respiratory depression Neurological assessment can be performed |
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What are the most common complications of interventional radiology?
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Hemorrhage
Contrast reaction Contrast nephropathy |
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What is the Cushing Reflex?
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Hypertension and Bradycardia that indicate an increased ICP
Usually caused by inadequate venting of irrigation fluids |
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What changes should we be aware of in prone position?
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Decreased cardiac index
Decreased venous return Decreased cardiac output Decreased left ventricular compliance Increased intrathoracic pressure Increased FRC V/Q mismatch is more favorable |
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How should you intubate somebody with limited cervical spine movement?
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Awake fiberoptic
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What is MILS?
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Manual In-Line Stabilization
Apply force to the head and neck equal in magnitude and opposite in direction to those generated by the laryngoscopist to limit movement caused by airway management |
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What is POVL?
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Post-Operative Vision Loss
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How is POVL caused?
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Impaired perfusion to the eye
- Decreased PP, MAP - Increased IOP |
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How should emergence of a neurosurgery look?
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Smooth - no cough reflex or hemodynamic changes that could effect ICP
Use short acting anesthetics and volatile agents Immediate neurological exam afterwards |
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What is atherosclerosis?
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Progressive thickening and hardening of arterial walls leading to lack of elasticity, gradual stenosis, and cardiovascular disease
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What ejection fraction puts you at a higher risk for vascular disease?
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< 35-40%
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What is the difference between thrombosis and embolism?
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Thrombosis is the clotting of blood in part of the circulatory system, whereas embolism is when the clot breaks off and travels through the bloodstream until it reaches an area too small to pass and blocks blood flow there
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What is claudication?
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Ischemia caused by exercise, often in the limbs, that causes pain or cramping when moving
Normal blood flow during rest, but impaired blood flow during exercise |
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What creatinine levels are linked to renal failure?
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Cr > 2.0 mg/dL
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What are the 6 independent predictors of complications related to CAD?
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High risk surgery
History of CAD History of CHF History of cerebrovascular disease Preoperative treatment with insulin Preoperative serum Cr > 2.0 mg/dL |
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General risk factors for vascular disease?
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History
Diabetes Hypertension Hyperlipidemia Smoking |
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What is unstable angina?
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Angina during rest or any change in the manifestation of angina in the last 6 months (intensity/duration)
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What 3 things should you ask a patient with aortic stenosis about?
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History of angina
Dyspnea on exertion Syncope |
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Who designed the cardiac risk stratification algorithm?
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ACC - American College of Cardiology
AHA - American Heart Association |
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What are low risk surgeries according to the cardiac risk stratification algorithm?
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Endoscopic Procedures
Superficial procedures Cataract surgery Breast surgery Ambulatory surgery |
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What are intermediate risk surgeries according to the cardiac risk stratification algorithm?
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Intraperitoneal/Intrathoracic surgery
CEA Head and Neck surgery Orthopedic surgery Prostate surgery |
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What are high risk surgeries according to the cardiac risk stratification algorithm?
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Aortic and other major vascular surgery
Peripheral vascular surgery |
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Compare TTE to TEE.
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TTE is less invasive and allows an awake patient.
TEE provides a better picture, but the patient must be asleep. |
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What is considered an acute MI?
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An MI documented 7 days or less before the examination
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What is considered a recent MI?
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An MI documented more than 7 days but less than a month before examination
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How many weeks should you wait after an MI to have elective surgery?
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4-6 weeks
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How long must the patient be on anticoagulants after drug-eluting stent placement versus bare metal stent placement?
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DES - 1 year
BMS - 4-6 weeks |
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What is the goal heart rate for patients that take beta blockers?
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60-65 bpm
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At ____% occlusion, carotid disease should be surgically treated.
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70
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How does Diabetes increase the risk of vascular surgery?
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Altered autonomic function
- blood pressure lability - variations in heart rate - gastroparesis --> aspiration Neuropathies obscure detection of MI |
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How does Pulmonary disease increase the risk of vascular surgery?
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Pneumonia is 2x as likely
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Why is dobutamine stress testing used?
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Allows testing in patients with bronchospastic lung disease or carotid stenosis that cannot exercise of bear other chemical tests (Adenosine and Dipyridamole cause bronchospasm)
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What does a dobutamine stress test do?
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Mimics intraoperative conditions by increasing the heart rate
Provides information about left ventricular function and valvular disease |
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Percutaneous Coronary Interventions (PCIs) can be done in what 2 ways?
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Stenting
Angioplasty |
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Compare/Contrast regional and general anesthesia for CEA.
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General
- Can control blood pressure and ventilation - Can use TEE Regional - Less hemodynamic fluctuations - Patient can serve as their own monitor |
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What is normal glucose?
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70-110 mg/dL
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What is it important to maintain normal glucose levels during CEA?
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Hyperglycemia can decrease perfusion and increase lactate levels
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What monitors do we need for CEAs?
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Standard ASA monitors
Arterial Line 2 large bore IVs |
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What are our anesthetic goals during CEA?
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Avoid hemodynamic extremes
Facilitate neurologic examination after surgery |
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__________________ causes the "steal" phenomenon/vasodilation and ________________ causes vasoconstriction.
Pick hypercapnia/hypocapnia for each blank. |
Hypercapnia; Hypocapnia
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What 4 goals do we have on emergence from CEA?
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Prevent hypertension
- prevent coughing and straining on extubation - Suction oropharynx - 60-80 mg 2% Lidocaine in the ETT - Adjust minimal pressure in the cuff carefully |
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Why is hypertension on emergence dangerous for CEA?
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It can cause rupture of the surgical anastomoses which leads to hematoma.
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What is hyperperfusion syndrome?
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An abrupt increase in blood flow with loss of autoregulation in the surgically re-perfused brain
Can cause headache and seizures |
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What are the advantages of using regional techniques for lower extremity vascular surgery? |
Avoidance of airway/pulmonary morbidity Lower blood loss Vasodilation helps sustain graft potency Less stress response |
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How long should Warfarin (Coumadin) be discontinued before regional anesthesia? |
4-5 days |
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What tests do you use when a patient is on Warfarin (Coumadin) or Heparin? |
PT: warfarin PTT: heparin |
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How do you choose which side to put the art line? |
Take a blood pressure on both sides and then put the art line on the side with the higher pressure |
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What are the two classes of abdominal aortic aneurysm and which one is higher risk? |
Suprarenal (higher risk) Infrarenal |
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Aneurysms greater than what size should be repaired? |
5-5.5 cm |
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What is important about temperature monitoring during AAA surgery? |
Normothermia should be maintained Do not warm the patients legs during cross-clamping |
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Why is hypothermia dangerous during AAA surgery? |
Vasoconstriction Coagulation altered Drug metabolism altered |
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What changes are seen during clamping of the AAA? |
Hypertension (more change the higher the clamp) Decreased contractility, HR, and cardiac output Lower metabolism rate Anaerobic metabolism increasing lactate levels Risk of renal and spinal cord ischemia |
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What drugs are often used to treat cardiac changes during AAA cross-clamping? |
Sodium nitroprusside (vasodilation) Nitroglycerine (venodilation) |
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How do we give renal protection during clamping of AAA? |
Maintain fluid balance Don't let the clamp time exceed 50 mins Mannitol (0.25-0.5 g/kg) Dopamine (3 mcg/kg/min) Fenoldopam |
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What is fenoldopam? |
Dopamine agonist with renal protective effects |
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What artery are we worried about when preventing spinal cord ischemia? |
Artery of Adamkiewicz |
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What is the most consistent response of un-clamping? |
Hypotension |
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What is EVAR? |
Endovascular aortic aneurysm repair |
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What are the advantages of EVAR over open AAA repair? |
Less hemodynamic lability Prevents acid:base imbalance, stress response Decreased risk of spinal cord ischemia |
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What are the complications of EVAR? |
Damage to iliofemoral vessels Embolization of atheromatous debris Radiographic contrast reactions Rupture of the aneurysm Displacement of the stent to occlude renal artery |
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How many extra-ocular muscles are there? |
Six |
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What is normal intraocular pressure? |
16 +/-5 mmHg |
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What is the function of the aqueous humor? |
Major transport system for oxygen, glucose, proteins, medications, and inflammatory cells 1/2 of the eye's oxygen supply - the other 1/2 is from diffusion of the air |
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The aqueous humor is formed by the: |
Ciliary body |
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What are some causes of increased IOP? |
Hypertension Hypoxia Venous obstruction Endotracheal intubation External pressure Ketamine Succinylcholine |
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Echothiopate Iodide |
Long acting acetylcholinesterase for glaucoma --Shorter than succ and ester local anesthetics |
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Congenital strabismus may be linked to: |
Myopathy; use MH protocol |
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In eye surgery, what causes increased risk? |
Patient movement Changes in IOP PONV |
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What are the criteria patients must meet to have eye surgery? |
Able to lie flat for the duration of the procedure Have no claustrophobia, head tremor, or dementia Be able to communicate sufficiently Able to comprehend that he/she will be awake or lightly sedated during the procedure |
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What are the problems with regional anesthesia for eye surgery? |
Patient cooperation - need akinesia |
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What is the issue with breathing under the drapes during eye surgery? |
CO2 can build up and cause hypercarbia, tachycardia, tachypnea, and restlessness Use suction or insufflate fresh gas under the drapes to prevent this |
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What patients are at higher risk for globe perforation during retrobulbar block? |
Patients with long axial globe length |
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Why is a severely increased IOP dangerous? |
Expulsion of the eye Ischemia |
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Are patient required to stop anticoagulation therapy prior to eye surgery? |
Only for retinal surgery |
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What is OPHTS? |
Serious complications for regional techniques: Optic Nerve Injury Perforation of the globe Hemorrhage Toxins (local anesthetic) Systemic complications (CSF spread and Cardiac arrest) |
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What is the oculocardiac reflex? |
Sinus bradycardia caused by eye manipulation Can also present as AV block or asystole |
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What is chemosis? |
Eye bruising (edema of the conjunctiva) |
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What is ptosis? |
congenital or acquired drooping eyelid |
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What is strabismus? |
ocular misalignment or deviation of one eye relative to the visual axis of the other |
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What is pterygium? |
Benign growth of conjunctiva and fibrovascular tissue that has invaded the superficial cornea |
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What is a cataract? |
Opacity of the lens |
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What is a vitrectomy? |
Surgical extraction of the vitreous humor and replacement with a physiologic solution |
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What is a blepharoplasty? |
Plastic surgery of the eyelids |
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What is a dacrocystorhinostomy? |
Creation of a communication between the lacrimal sac and the nasal cavity to allow for tear drainage |
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What are the main things we should think about when considering open globe surgery? |
PONV risk Careful or non-use of succinylcholine and N20 Avoid rises in IOP |
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What are the main factors that contribute to respiratory risk in children? |
Younger age Concurrent disease (syndromes, airway anomalies, OSA) Recent URI Airway procedures (tonsillectomy, cleft palate) |
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What are the main respiratory risks for children during surgery? |
Laryngospasm Bronchospasm Airway obstruction Decreased systemic oxygen saturation |
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What age causes the highest risk for apnea postoperatively? |
Premature children |
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What drug should be use cautiously in children that have no medical history? |
Succinylcholine - could cause cardiac arrest in children with unknown myopathy and hyperkalemia |
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How long should a case be postponed due to URI in children? |
2 weeks |
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How long should you wait to do general anesthesia on a baby? |
50-60 post-conceptual weeks (2&1/2-3 months old) |
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What poses the higher risk in children: cardiac or respiratory risk? |
Respiratory risk - bradycardia is usually just a sign of hypoxia |
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What circuit did we use on pediatric patient in the past? Now? |
Past: Mapleson D Now: Circle system |
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What side should you place the precordial stethoscope one? Why? |
The left side - so you can detect mainstem intubation |
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What is the maximum dose of midazolam for kids? |
15 mg |
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What is the maximum dose of tylenol for kids? (PO and Rectal) |
PO: 15 mg/kg Rectal: 40 mg/kg |
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What is the premed PO dose of midazolam? |
0.5-0.75 mg/kg |
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What is the premed IM dose of ketamine? |
2-3 mg/kg |
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What could be used a replacement for premedication in children? |
Parental presence during induction Distraction usually works better than reassurance |
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When do we usually stop doing inhalational inductions? |
8-10 years old |
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Emergence delirium is more associated with which inhaled gas? |
Sevoflurane |
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How do you do an inhalation induction in children? |
70% N20, 30% O2, 8% Sevo (or increment up to expired of 4%) Wait for excitement phase to finish Establish IV access |
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What does the excitement phase in children look like? |
Limb movement Rigidity Rapid respirations Tachycardia |
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What size IV should we use on kids? |
22 G (blue) |
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If succinylcholine can be given, what should always be given before? Why? |
Atropine to prevent the potential for bradycardia |
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What muscle relaxant can be used in RSI instead of succinylcholine? |
Rocuronium |
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A straight blade should be used in children under ___________ years old. |
Two |
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What is the preferred leak that should be seen with an ETT in children? |
20-25 cmH2O |
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What is the formula for tube depth in children? |
Tube depth (cm) = 3 x Tube size |
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What is the dose of IM succinylcholine? |
2-4 mg/kg |
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What is the pediatric induction dose for propofol? |
1-3 mg/kg |
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What is the pediatric induction dose for ketamine? |
1-2 mg/kg |
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What is the pediatric IV dose for succinylcholine? |
1.5-2 mg/kg |
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What is the pediatric IV dose for rocuronium? |
0.45-0.6 mg/kg 1 mg/kg RSI |
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What is the pediatric IV dose for vecuronium? |
0.1 mg/kg |
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What size LMA's correspond to weight in children? |
<5 kg = 1 (infants) 5-10 kg = 1.5 10-20 kg = 2 20-30 kg = 2.5 30-50 kg = 3 |
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What size tube and blade would you use on a premature neonate? |
2.5-3 tube Miller 0 |
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What size tube and blade would you use on a term neonate? |
3-3.5 tube Miller 0-1 |
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What is the formula for pediatric tube size? |
Uncuffed: Age/4 +4 Cuffed: (Age/4 +4) - 0.5 |
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What do we need to see in children to do a deep extubation? |
Spontaneous ventilation No response to suctioning, jaw thrust, or slight in and out movement of the tube |
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What is the common amount for a fluid bolus in pediatrics? |
10-20 ml/kg |
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When should we consider giving IV Dextrose to a child? |
Neonates Critically ill child with limited metabolic reserve Children who receive tube feedings Children with inborn hypoglycemia |
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How much blood volume can be lost before a child requires transfusion? |
20% |
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How much can PRBCs raise hematocrit in children? |
1 PRBC (10 ml/kg) will raise hematocrit 6-10% |
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What is the hematocrit of a PRBC? |
70% |
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What are the risks of transfusion in kids? |
Thrombocytopenia Depletion of clotting factors |
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How much will giving platelets effect the child's platelet count? |
10 ml/kg platelets will raise platelets by 100,000/mm3 |
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What is the dose of FFP for kids? |
5-10 ml/kg |
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How do you perform a caudal block? |
Needle in the sacral hiatus It is a form of epidural |
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The max amount of local anesthetic you can use for epidural or spinal in a child is: |
1 ml/kg |
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What is the pediatric IV dose for ketorolac? |
0.5 mg/kg |
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What is the pediatric IV dose for fentanyl? |
1-2 mcg/kg |
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What is the pediatric IV dose for zofran? |
50-100 mcg/kg up to 4 mg |
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What is the pediatric IV dose for decadron? |
150 mcg/kg up to 8 mg |
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What surgeries in children cause a higher incidence of PONV? |
Strabismus Adenotonsillectomy Orchidopexy Laparoscopic |
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What is the 4-component risk of PONV score based on for children? |
Surgery 30 minutes or longer Age > 3 years Strabismus surgery Positive history of PONV in child, parents, or siblings |
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What are some agents you can give to reduce post-operative delirium? |
Fentanyl Ketamine Clonidine Dexmedetomidine |
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Why is an orchidopexy performed? |
Young boys who testes are undescended |
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What it hypospadias repair? |
Correction of a birth defect of the urethra where the urinary opening is not at the correct location on the head of the penis |
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What are some reasons to do laparoscopy on a child? |
Cholecystectomy Appendectomy Fundoplication Visualization of the contralateral side of hernia repair |
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What is the smallest size available for a DLT? |
26 Fr (slightly larger than a 6.5 ETT) |
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Since the smallest DLT is quite large, what is the option for younger children? What age? |
Bronchial blockers or intentional mainstream must be done in children under 6 years old |
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What is pectus exavatum? |
A common congenital chest wall deformity of children causing compression of the mediastinum (lungs and heart) |
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What is the most common extracranial tumor of childhood? |
Neuroblastoma |
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What is Wilms tumor? |
Nepharoblastoma (requires nephrectomy) |
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What is the most common reason that a child needs a craniotomy? |
Infratentorial tumors ---medulloblastoma and astrocytoma |
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What is craniosynostosis? |
Premature closure of 1 or more of the cranial sutures |
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What are the symptoms of craniosynostosis? |
Increased ICP Decreased CPP Obstructive respiratory symptoms during sleep |
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What are the most common complications of craniosynostosis? |
Need for transfusion (in 95% of patients) Venous air embolism |
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How old do you have to be to be considered a neonate? |
From birth to 1 month old |
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How old do you have to be to be considered a newborn? |
From 1 month to 1 year |
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How long does it take the P450 system to mature? |
1-2 months |
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What happens to total body water, extracellular fluid, intracellular, blood volume, muscle mass, and fat as you go from a child to adult? |
Total body water: Decreases EC fluid: Decreases IC fluid: no change Blood volume: Decreases Muscle mass: increases Fat: increases |
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What happens with the dosing of Atropine in neonates? |
You have to give a higher dose, if you don't give a high enough dose you can get paradoxical bradycardia |
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What happens with protein binding in neonates? |
Less proteins than at any other point in life Proteins have lower affinity for drugs |
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What happens to the volume of distribution in neonates? |
Large Vd |
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______% blood flow goes to the brain in infants, whereas _______% blood flow goes tot he brain in adults. |
30%; 15% |
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Which inhalational agents produce unacceptable hypotension in newborns? |
All |
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What is the neonatal heart like? |
Myocardium is less compliant and has less contractile velocity Fixed stroke volume CO depends on heart rate Baroreceptor reflexes are blunted |
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What is the dose of atropine in neonates? |
0.3-0.5 mg/kg |
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Why do infants fall asleep so fast? |
3-4x the minute ventilation of older children, but the same FRC Much lower mass |
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What happens to the MAC of neonates? |
It is lower with age (premature has an even lower MAC than neonate) |
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Infants are ________ sensitive to non-depolarizing muscle relaxants. |
More |
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Why would we use succinylcholine in infants? |
Laryngospasm "Full stomach" precautions/RSI |
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Ketamine is the drug of choice for patients with: |
CHD Asthma Cardiac tamponade |
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What type of flow do we measure with the pulse ox on the right hand in the neonate? Why? |
Pre-ductal flow: reflects the coronary and cerebral oxygenation Helps prevent retinopathy of the premature (ROP) |
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Why is it bad to hyperoxygenate a neonate? |
Increases the risk of retinopathy of the premature (ROP) |
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What are the consequences of hypothermia? |
More likely to go apneic Reduced MAC Increased O2 demand --> acidosis Peripheral & Pulmonary vasoconstriction Right to left shunt |
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Why do neonates get cold quickly? |
They have a high surface area to mass ratio They can't shiver |
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What is the minimum urine output for neonates? |
0.5-1 ml/kg/h |
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In infants, don't let hematocrit fall below _____%. |
35% |
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Infants are born with a ___________ hematocrit than adults. |
Higher (>50%) |
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Massive transfusion can produce: |
Hyperkalemia Coagulopathy |
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What is the ABL for a neonate? |
loss of 20 ml/kg usually safe to transfuse |
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To reduce the risk of infection due to blood transfusion in neonates, which cell should be left out of blood? |
Leukocyte depleted products should be used |
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What is a congenital diaphragmatic hernia? |
Herniation of the diaphragm into the thorax that often causes decreased number and size of the bronchi, lung saccules, and alveoli of affected lung |
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Which side of the diaphragm is more likely to herniate into the thorax for CDH? |
Left |
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What do patients with congenital diaphragmatic hernia usually present with? |
Dyspnea Cyanosis Dextrocardia |
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What condition is associated with congenital diaphragmatic hernia? |
Persistant Fetal Circulation (PFC)/ Persistant Pulmonary Hypertension (PPH) |
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What is PFC? |
Right to left shunting |
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How do you treat congenital diaphragmatic hernia? |
Don't use inhalational agents or N20 Don't use high airway pressures to ventilate ---Risk of pneumothorax to good lung! Vasodilator therapy (isoproterenol, nitroglycerine, adenosine, nitric oxide) |
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What is an omphalocele? |
A MIDLINE defect that is ALWAYS associated with other congenital abnormalities Herniated bowel covered by amniotic sac Umbilical cord at apex |
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What is gastroschisis? |
NOT a midline defect, RARELY associated with other congenital abnormalities Herniated bowel burned by amniotic fluid (no sac) Umbilical cord at side |
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What is Hirschsprung disease? |
Functional distal obstruction caused by a lack of ganglion in the rectum and distal colon |
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What is necrotizing enterocolitis (NEC)? |
Bacterial infection of previously injured or ischemic bowel wall |
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How does NEC normally present? |
Sepsis Hypotension Thrombocytopenia Respiratory Failure Metabolic and Respiratory Acidosis Electrolyte disorders |
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What does VATER stand for in the syndrome? |
Vertebral Anal Tracheoesophageal Fistula Esophageal atresia Renal anomalies |
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How do you know if an infant has pyloric stenosis? |
Projectile vomiting that results in hypochloremia and hypokalemia, metabolic alkalosis, and profound dehydration |
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What is the most common type of tracheoesophageal fistula? |
Blind esophageal pouch and distal esophageal fistula attaching to distal trachea |
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What approach do they use to correct tracheoesophageal fistula? |
Right sided thoracotomy |
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How do you manage a Right sided thoracotomy for tracheoesophageal fistula? |
Spontaneous ventilation with Sevo and 100% O2 |
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Where is the ductus arteriosus? |
From the aorta to the pulmonary artery |
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What happens if the ductus arteriosus doesn't close? |
Left to right shunt --> too much blood to the pulmonary circulation --> right heart failure --> left heart failure |
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What are the considerations for surgery for patent ductus arteriosus? |
Fluid restoration Lung retraction is necessary -- pretreat with atropine b/c of vagal stimulation |
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What is coronary artery disease? |
Atherosclerosis results in decreased blood flow. Oxygen delivery does not meet demand, leading to ischemia. |
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What are the risk factors for coronary artery disease? |
Genetics Diet Environment Hypertension Smoking Diabetes |
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What factors affect myocardial oxygen demand? |
Wall tension Contractility Heart rate |
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What factors affect myocardial oxygen supply? |
Coronary blood flow (diastolic pressure) Diastolic time (Heart rate) Oxygen saturation Oxygen extraction |
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What part of the heart is most vulnerable to ischemia? |
Left ventricular subendocardium |
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What is the most sensitive indicator of myocardial ischemia? |
TEE |
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What can TEE tell us about? |
Wall motion abnormalities Ventricular volumes and function Measurement of valve gradients and regurg Visualization of air in the heart Detecting CAD/atherosclerosis |
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Anesthesia for patient's heart surgery should be tailored to the patient's: |
Ejection fraction - depends on the degree of left ventricular dysfunction! |
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Which gas can be used as a coronary vasodilator? |
Isoflurane |
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Which gas can cause tachycardia, HTN, and increased plasma epi if inspired quickly? |
Desflurane |
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What is the drug of choice for coronary vasospasm? |
NTG - venodilator Nifedipine and Diltiazem also work |
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How do you treat CAD if the patient's blood pressure and PCWP begins to increase? |
NTG or increase anesthetic depth |
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How do you treat CAD if the patient's HR starts increasing? |
Beta blocker |
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How do you treat CAD if the patient's BP drops? |
Decrease anesthetic depth or Phenylephrine |
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How do you treat CAD if the patient's BP drops but PCWP increases? |
NTG, phenylephrine, inotrope |
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How do you treat CAD or ischemia in a patient who's hemodynamics haven't changed? |
NTG or calcium channel blocker |
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What are some indications of myocardial dysfunction? |
LVEDP > 18 mmHg EF < 40% Cardiac index < 2 L/min/m2 History of CAD ECG shows ischemia or infarction TEE wall motion abnormalities |
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If the patient has poor LV function, what anesthetic might be best? |
High dose narcotics |
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What are the stages of heart surgery? |
Sternal incision, dissection, heparinization, ECHO of aortic cannulation site, aortic cannulation, venous cannulation, bypass, cross-clamp and cardioplegia, circulatory arrest, surgical procedure, rewarming, ECHO of LV to ensure no bubbles, separation from bypass, reversal of anticoags |
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What is the definition of CPB? |
Mechanism to replace the work of the heart and lungs while the heart is arrested. Allows for a bloodless and stable surgical field. |
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What is LAMPS, acronym used before starting CPB? |
Labs - ABG, K+, ACT Anesthesia Monitors Patient Support |
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What should the ACT be before going on bypass? |
ACT > 400 s Check this every 30 minutes while on bypass |
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What are the components of CPB? |
Circuit/Reservoir Oxygenator Pump Heat exchanger Prime Anticoagulants Myocardial protection |
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In CPB, blood is drained from the ______________ and returned to the ______________. |
Right atrium; Ascending Aorta |
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What are the dangers with setting the pump pressures in CPB? |
Too high: more damage to blood, cycles more Too low: less damage to blood, cycles less - possible perfusion problem |
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What is the function of the prime in CPB? |
Dilutes the patients blood to HCT < 30% |
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What are 2 forms of myocardial protection used during CPB? |
Hypothermia - 10-15 C Cardioplegia - K+ arrests the heart in diastole |
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Cardioplegia can be administered through what structures of the heart? |
Aortic root Coronary sinus Newly created bypass grafts |
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What should we be doing during aortic cannulation? |
Systolic blood pressure should be brought down to 80-100 mmHg to prevent aortic dissection NTG works for this |
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What is the most likely cause of neurologic injury after CPB? |
Embolism |
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During CPB, what stage has the greatest chance for awareness? |
Rewarming - administer a benzodiazepine to help during this stage |
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What could be some reasons for low cardiac output when coming off pump? |
Kinked graft Air in the grafts Coronary artery spasm Tamponade Global ischemia due to inadequate protection |
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How do you dose protamine? |
1 mg/ 100 U Heparin given or 3 mg/kg Give slowly through peripheral IV |
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During CPB how do you measure temperature? |
At 2 different sites: rectal/bladder and nasal |
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What is an intra-aortic balloon pump (IABP)? |
Mechanical assist device in the thoracic aorta to enhance stroke volume Balloon inflates during diastole, deflates during systole |
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In IABP, why does the balloon inflate during diastole? |
To increase coronary flow |
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In IABP, why does the balloon deflate during systole? |
To decrease afterload and myocardial oxygen requirements |
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Chest closure is usually associated which what side effect? |
Hypotension - if it is prolonged, reopen the chest to rule out tamponade or kinked graft |
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What are the signs of cardiac tamponade? |
Fixed stroke volume and cardiac output Hypotension Tachycardia |
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What is the primary problem with stenotic lesions? |
Pressure overload |
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What are the general hemodynamic goals for managing stenotic lesions? |
Avoid increased HR (Des, Panc, etc.) Avoid decreased SVR (neuraxial techniques) |
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Which valve is bigger? Aortic or Mitral? |
Mitral valve (4-6 cm2) compared to 2.5-3.5 cm2 |
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Aortic valve surgery is indicated when the valve gradient is: |
> 50 mmHg |
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What murmurs do you see with aortic stenosis? mitral stenosis? |
Aortic stenosis: systolic murmur Mitral stenosis: diastolic murmur |
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Mitral stenosis can lead to: |
Pulmonary edema Right ventricular hypertrophy Atrial Fibrillation Thromboembolism Limited cardiac output |
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What is the most common cause of mitral stenosis? |
Rheumatic fever |
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Which drug is good to control AFib due to mitral stenosis? |
Digoxin or Verapamil |
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What are the primary causes of aortic stenosis? |
Rheumatic Fever Bicuspid aortic valve Calcification of aortic cusps |
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What is the triad of symptoms for aortic stenosis? |
Angina CHF Syncope |
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Aortic stenosis can lead to: |
Left Ventricular hypertrophy Increased demand on the coronaries Fixed cardiac output (dependent on atrial kick) |
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What is the primary problem with regurgitation? |
Volume overload |
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What are the murmurs for aortic regurgitation? mitral regurgitation? |
Aortic R: Diastolic murmur Mitral R: Systolic murmur |
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What are the causes of mitral regurgitation? |
Rheumatic fever Endocarditis MI - ruptured chordae Congenital heart disease Trauma (steering wheel injury) |
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What are the differences between acute and chronic mitral regurgitation? |
Acute - higher pressures Chronic - left heart enlargement, Afib |
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What are the symptoms of mitral regurgitation? |
Fatigue, nocturnal dyspnea, orthopnea AFib Left ventricular dissension leads to: Right heart failure - pulmonary HTN, hepatic congestion, peripheral edema, jugular venous distension |
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What are the anesthetic goals for regurgitations? |
Small increases in HR Decrease SVR - regional is a good choice for these (FULL, FAST, VASODILATED) |
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What is the difference between what happens to the left ventricle with aortic stenosis and regurgitation? |
Stenosis: concentric hypertrophy
Regurgitation: eccentric hypertrophy |
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What diseases can be associated with concurrent aortic regurgitation? |
Marfans Rheumatoid arthritis |
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What is the difference between receiving a mechanical valve or tissue valve? |
Mechanical: must being anticoag therapy immediately (2-3 days post-op) for the rest of your life Tissue: must be replaced after 12-15 years |
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Which patients have a better prognosis? Aortic stenosis or regurgitation? |
Aortic stenosis |
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What is Marfan's syndrome? |
Familial defect of collagen synthesis that causes decreased tensile strength and elasticity of connective tissue |
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What are some common symptoms of Marfan's syndrome? |
Lens dislocation Aortic dissection Arrythmias MVP Spontaneous pneumothorax Joint hypermobility/Recurrent dislocation Tall stature |
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What are the anesthetic concerns with a Marfan's patient? |
Difficult intubation - possible c-spine instability or TMJ dislocation, high arched palate Positioning - watch for dislocations Avoid sudden increases in aortic wall tension |
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What is the definition of a shunt? |
When the venous return of one circulation is redirected back to the arterial outflow of the same circulation. |
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Left to right shunts occur in the _______________ circulation, whereas right to left shunts occur in the ______________ circulation. |
Pulmonary; Systemic |
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A left to right shunt can cause: |
Hypotension Pulmonary edema Increased PVR due to high flow |
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|
A right to left shunt can cause: |
Arterial oxygen desaturation (cyanosis) |
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|
What are the left to right shunt abnormalities? |
ASD VSD AVSD Hypoplastic left heart Truncus arteriosus |
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|
What are the right to left shunt abnormalities? |
Transposition of the great vessels Tetrology of Fallot Tricuspid atresia Total anomalous pulmonary venous return |
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|
What are the classic signs of cardiac ischemia? |
Angina Shortness of breath Nausea or lightheadedness Fatigue (in women) |
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|
What subcategory of people are more likely to have a silent MI? |
Diabetics - because of PVD they don't feel the pain of ischemia like others would |
|
|
What is the major cause of mortality among those who survive burn shock? |
Burn wound sepsis |
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|
What happens in regards to fluids in a burn victim? |
Generalized capillary leak syndrome - Decreased plasma volume - Decreased cardiac output - Decreased urine output - Hemoconcentration |
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|
Edema occurs in unburned tissues when the burn covers ____% TBSA and includes plasma protein loss. |
25 |
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|
What is the hemodynamic response to burns in the early period as compared to later? |
Early: decreased CO, increased SVR/PVR 3-5 days later: hyper metabolic state, increased CO to double |
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|
What are the 3 mechanisms of inhalation injury after a fire? |
Direct thermal injury to upper airways Inhalation of CO/CN Chemical injury to lower airways |
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|
Inhaling CO can cause what heart problem? |
Myocardial stunning |
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|
Inhaling CN can cause what heart problem? |
ST elevation which mimics MI |
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|
What does CN- do? |
Binds to mitochondrial cytochrome oxidase to prevent the use of oxygen by mitochondria (the cells can only do anaerobic metabolism) |
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|
What is the Parkland formula for fluid resuscitation? |
4 ml/%TBSA burn/kg over the first 48 hours 1/2 of that should be given within the first 8 hrs |
|
|
What 3 risk factors predict death after burns? |
Age > 60 yrs Burn size > 40% TBSA Inhalation injury |
|
|
What are the degrees of burns? |
First: superficial, epidermis Second: partial-thickness, blistering Third: full thickness Fourth: Injury to muscle, fascia, or bone |
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|
Which degree burns usually require grafting? |
Deep second and third |
|
|
What is the most common cause of death due to electrical injury? |
V Fib |
|
|
What is different about electrical burns compared to thermal burns? |
Many have secondary injuries involving falls, being thrown against an object, or tetanic muscle contractions Myoglobinuria - tinted urine |
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|
What are the common problems related to burn patients? |
Altered response to anesthetics and MRs Altered ventilatory status Difficult airway management Difficult IV access and monitoring Marked potential for hypothermia |
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|
What are the 2 most common fluid resuscitation formulas? |
Parkland Brookes |
|
|
What is known about the use of succinylcholine for burn patients? |
Safe to use up to 24-72 hours, but then ACh receptors are too unregulated to use it It is not safe to use again until 6 months - 1 year after the injury has healed |
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|
How should a burn patient be ventilated? |
Lower tidal volumes (6 ml/kg) Allow hypercarbia Increased oxygen consumption may require higher minute volumes |
|
|
How is drug pharmacodynamics affected in the burn patient? |
Less albumin, drugs don't last as long |
|
|
Which induction agent is preferred in burn patients? |
Ketamine |
|
|
Burn patients may develop tolerance for narcotics because of how much they need to recover. What are some good drugs to give them? |
Clonidine, Dexmeditomidine |
|
|
What are the 3 main types of traumatic injuries? |
Penetrating Blunt Burn |
|
|
What is SIRS? |
Systemic Inflammatory Response - patients may have a generalized imbalance of cytokines, metabolites, and inflammation as a response to injury or infection |
|
|
When you transfuse a large amount of blood, what is the first factor to decrease? |
Platelets, then clotting factors |
|
|
In massive transfusion of only RBCs we are worried about depleted: |
Platelets (thrombocytopenia) Calcium (hypocalcemia) |
|
|
What is the most deadly transfusion reaction? |
Acute hemolytic |
|
|
What transfusion reactions are the most common? |
Non-hemolytic febrile transfusion reactions |
|
|
What are the symptoms of an acute hemolytic response in the asleep patient? Awake? |
Asleep: fever, hypotension, hemoglobinuria Awake: chills, pain |
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|
What is the lethal triad? |
Coagulopathy Hypothermia Acidosis |
|
|
What is the ABCDE of patient surgery and resuscitation for trauma? |
A - Airway B - Breathing C - Circulation D - Disabilities E - Environment, Exposure |
|
|
According to the Glasgow coma scale, at what number value does the patient need to be intubated? |
< 8 |
|
|
What is DIC? |
Disseminated Intravascular Claudication A consumptive coagulopathy - all coagulation factors are consumed in extreme clotting, then bleeding resumes when they run out |
|
|
What does FFP contain? |
Plasma Factor V, VIII |
|
|
What does cryoprecipitate contain? |
Factor VIII Fibrinogen vWF |
|
|
How is airway management approached for the trauma patient? |
They are all full stomach They are all treated as C-spine injuries (use MILS) - evaluate them afterwards Avoid nasal intubation |
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|
How long can you hyperventilate until it becomes a danger to the brain (low ICP)? |
6 hours |
|
|
What are the symptoms of fat embolism? |
Decreased ETCO2 Tachycardia Hypotension Increased PCO2 Awake: confusion, petechiae |
|
|
What is compartment syndrome? |
Edema causes pressure build up in a compartment, impairing blood flow to the surrounding tissues. |
