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367 Cards in this Set

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What are the 4 primary functions of the kidneys?
1. Excretion of end products of bodily metabolism
2.Control of constituents of body fluids (filtration/ reabsorption)
3.Secrete hormones such as renin and erythropoetin
4.Metabolism of hormones (such as insulin)
What is the functional unit of the kidney?

How many are there in each kidney?
The nephron

1.2 million in each kidney
What are the components of the nephron?
Glomerulus, proximal convoluted tubule, loop of Henle, distal convoluted tubule, and collecting duct
How much of the cardiac output goes to the kidneys?
20%
Between what MAPs does auto regulation of blood flow and glomerular filtration take place (in an adult)?
80-180 (remains constant)
Renal blood flow is strongly influenced by ____ and _____.
SNS and renin
What do the kidneys manufacture in response to systemic hypotension and renal ischemia?
Prostaglandins
What do prostaglandins do?

What purpose does this serve in the kidneys?
Vasodilate

Vasodilates to allow more blood flow to the kidney
What tests help you evaluate the GFR?
BUN- elevation can be related directly to GFR or to protein catabolism
Creatinine: directly related to muscle mass, indirect indicator of GFR
Creatinine clearance (derived from a formula accounting for age, weight, sex, etc)
What tests help you to evaluate the function of the renal tubule?
Urine dip (proteinuria, urine specific gravity), urine osmolarity, 24 hour urine collection
What is a normal GFR?
About 120 ml/minute
A BUN >____ indicates impairment of GFR
50
Urine that is positive for protein should be evaluated by what further test?
24 hour urine collection
What two anesthetic agents may cause direct nephrotoxicity?
Methoxyflurane
Sevoflurane (Compound A)
How do anesthetics indirectly affect the kidneys by way of the cardiovascular system? The SNS?
Anesthetics may cause hypotesion which can lead to decreased GFR and decreased UOP; Regional anesthetics cause a decrease in sympathetic tone, leads to vasodilation and hypotension, again decreasing GFR and UOP
Catecholamines and Angiotensin II lead to ____
Fluid retention
What are the 4 stages of renal impairment?
1. Decreased Renal reserve
2.Renal insufficiency
3.End Stage Renal Disease
4. Uremia (dialysis dependent)
Chronic renal disease may lead to______.

Why?
Anemia

Decreased erythropoetin production
Chronic renal disease may have this affect on cardiac output:

Why?
Increased cardiac output

Decreased oxygen carrying capacity d/t anemia
Chronic renal disease does this to platelets:
Reduces platelet adhesiveness
Renal failure leads to ___kalemia
Hyper
When a person is in chronic renal failure, their intravascular volume is_____.
Unpredictable
Chronic renal failure leads to what type of pH?
Metabolic acidosis
Chronic renal disease leads to this type of blood pressure
Systemic hypertension
Chronic renal disease makes patients more at risk for ____
Sepsis
ESRD patients should undergo ____ within 24 hours prior to surgery
Dialysis
What lab values to you want to know about your ESRD patient prior to surgery?
K (especially related to succinylcholine administration); BUN, Creatinine,
Antihypertensive medications should be _____ prior to surgery.
Continued (D/C may lead to rebound hypertension)
What are good alternative medications to succinylcholine if your patient's potassium is elevated?
Cisatracurium, Atracurium (because they are not metabolized by the kidneys)
Is it ok to give sucinylcholine to ESRD patients?
Only if their potassium is ok
Why would an end stage renal disease patient exhibit an exaggerated response to IV induction agents?
Decreased protein binding (more free drug floating around)
You would not want to give Atracurium or Cisatracurium to your patient if they have a history of ____.
Seizures
Why might your ESRD patient exhibit an exaggerated decrease in BP?
May reflect ANS dysfunction or a impaired baroreceptor mediated reflex response
Do you want to maintain general anesthesia with short or long acting opiods in your ESRD patient? Why?
Short acting, because of duration of effect with renal clearance
Normocarbia is especially important in your ESRD patient Why?
acidosis increases potassium level
What piece of equipment might you use to keep close track of fluid administration in the OR for your ESRD patient?
A buretrol
meticulous attention to fluid balance is especially critical in patients with ESRD. What fluid do you want to replace intravascular volume with? Which do you specifically want to avoid, and why?
NS,
Avoid LR because it contains about 4meq K/L
AV shunts must be carefully protected inraop. What piece of documentation is imperative in these patients?
Presence of bruit both before and after surgery
Which opiod might you specifically want to avoid in ESRD patients?
Morphine; metabolites can accumulate
What type of block might be useful for placement of an AV graft?
Brachial plexus block
The duration of a block in an ESRD patient might ____ by as much as ___%. Why?
Decrease, 40%, d/t increased cardiac output and increased tissue blood flow
Co-existing neuropathies in ESRD might ____ seizure threshold for local anesthetics
Decrease
Before selecting regional route of anesthetic for your ESRD patient, you should check ____ and document ______.
Coags, Uremic neuropathies
Many NDMR undergo extensive ____ in the _____.
Excretion from the kidneys
In your ESRD patient, you would want to _____ the dose of NDMR and _____.
Decrease, monitor
Causes of 'pre renal' ARF:
1. Hypovolemia
2. Decreased renal blood flow d/t decreased cardiac output
Acute renal failure caused by acute tubular necrosis can be caused by:
1. Nephrotoxins
2. renal ischemia
3. Circulating myoglobin (crush injuries)
Post-renal causes of ARF are:
urinary Obstruction
Signs and symptoms of acute renal failure:
Elevated BUN/creatinine, fluid retention, sodium and water retention, acidosis, hyperkalemia, nausea/vomiting, easy bruising/bleeding, decreased UOP, changes in mood/mental status
Pre-renal oliguria is indicated with______ urine with a _____ sodium content
Concentrated, low sodium content- indicates renal function is intact, body is trying to preserve water and sodium through reabsorption to increase intravascular volume
Oliguria is defined as:
less than 0.5 ml/kg/hr or 400 ml/day in adults, <1 ml/kg/hr pediatrics
What are the goals of therapy in treating pre renal oliguria/ARF?

What is the first thing you would do to accomplish this?
Limit the duration and magnitude of reduction in Renal Blood Flow

Volume! (crystalloid)
A fluid challenge to confirm a diagnosis of pre-renal ARF would consist of:
3-6 ml/kg
If oliguria is due to decreased cardiac output, _____ might be considered
Dopamine 3-5 mcg/kg/min
In establishing a diagnosis of pre-renal ARF, a 0.1mg/kg dose of Lasix would improve symptoms if_____, but not if______.
oliguria is due to ADH, but not if it is due to decreased RBF
What is the first thing you should do if you are suspecting that your patient has new onset oliguria?
Check the patency of your catheter
Does administering diuretics in oliguric ARF prevent the development of tubular necrosis
Evidence in support of this theory is lacking, controversial. Does cloud picture of sodium reabsorption from urine for about 6 hours (making diagnosis more difficult)
You must restore _____ before giving a _____ to a patient in pre renal ARF
Intravascular volume, diuretic;
Fluid volume in ARF is best assessed with
CVP or PCP
Is urine sodium excretion increased or decreased in patients with ATN?
Increased (>40 meq/L)
Urine is ____ concentrated in ATN
poorly
What lab level must you carefully monitor in ATN?
Potassium, hyperkalemia may result
Residual Volume
The amount of air remaining in lungs after forced expiration
Expiratory reserve volume:
Amount of air that can be expired after normal tidal volume
Tidal Volume
Volume of air inspired and exhaled on each regular breath
Inspiratory Reserve Volume
Max additional volume that can be inhaled above normal tidal volume
Inspiratory Capacity
Max volume of air inspired from end expiratory level
Vital Capacity
Max capacity of air that can be expired following a maximal inhalation
Functional Residual Capacity
Volume of air remaining in lungs after at end expiratory level
Total Lung Capacity
Volume of air in lungs after maximal inhalation (5800 ml)
Functional residual capacity is influenced/determined by what factors?
Body habitus (height, obesity), sex, posture, positioning (supine vs. upright), lung disease, diaphragmatic tone
What effect does lying supine have on functional residual capacity?
Decreases
Can the residual volume of air be exhaled voluntarily?
No
Vital Capacity is influenced/determined by:
Body habitus (height), respiratory muscle strength, lung compliance
What is a normal vital capacity for an adult?
60-70 ml/kg
Induction of anesthesia has what effect on your diaphragm?

What effect does this have on lung volume and chest wall compliance?
Loss of diaphragmatic tone

Decreased lung volumes and decreased compliance
What effect will Trendelenberg positioning have on lung volumes?
HOB elevation?
Decreased
Increased
Do NMB agents affect lung volumes?
No
How long after anesthetic agents are turned off will poor diaphragmatic tone persist?
Can last for hours after agents off
What are 6 common causes of obstructive pulmonary disease?
Asthma, Chronic Bronchitis, Emphysema, cystic fibrosis, bronchiectasis, bronchiolitis
What do all obstructive lung diseases have in common?
Resistance to airflow
In obstructive lung diseases, increased resistance to flow leads to...
Air trapping (increased residual capacity), increased WOB, VQ mismatch
Wheezing is caused by
Turbulent flow
VQ mismatch and resistance to airflow can lead to____
Abnormal oxygen exchange and arterial hypoxemia
What is FEV1
Amount of air that can be exhaled in 1 second
A FEV1/FVC of less than ____ is diagnostic for obstructive respiratory disease
<70%
MMEF (maximal mid-expiratory flow) less than ____ is indicative of COPD.
When does this value begin to change?
<70?

Begins to decrease before demonstratable symptoms of COPD begin
COPD generally has what effect on lung volumes?
Increased Total Lung Capacity and Residual Volume
What are two common respiratory finding in COPD?
Wheezing and dyspnea
Asthma is characterized by ______ and ______ in response to various stimuli
Bronchiolar inflammation and hyperactivity
Asthma attacks are manifested by:
Episodic attacks of wheezing, dyspnea, and cough (with increased mucous production)
Early uncompensated acute asthma attacks lead to what three 'value' changes?
Hypoxia,
Hypocapnia (from hyperventilation)
Respiratory Alkalosis (from blowing off CO2)
What lab values increase your level of concern in an asthmatic in acute distress?
Normalizing or elevated CO2, normalizing or decreasing pH
What happens to the airway during an asthma attack?
Reduction in airway diameter, inflammatory thickening of bronchial mucosa, accumulation of tenacious secretions
With asthma, what chronic changes can take place in the lungs and airway over time?
Lung hyperinflation, pulmonary hypertension, loss of elasticity
What effect does Asthma have on the heart?
Strain on R. and L. heart, increased lung volumes can cause pulsus paradoxus, EKG changes
What EKG changes might you see in an acute asthma exacerbation?
ST segment changes
What questions do you want to make sure to ask in a preoperative assessment of a patient with a history of asthma?
Previous hospitalizations for asthma, date of last attack, wheezing or SOB, cough/sputum production, allergy history, treatment regimen, EKG, CXR, and eosinophil count (may increase preceding attack)
When would regional anesthesia not be a good choice for patients with Asthma, COPD or other lung disease?
Spinal block that might travel high enough to impede respiratory muscle strength or weaken diaphragm
Is regional or general anesthesia a better choice for someone with asthma (or other lung disease)?
Neither method is inherently superior; situational
Why might you encourage your patient to quit smoking for even 12-14 hours before surgery?
Reduces carboxyhemoglobin
What airway device might you use in a patient with asthma?

What is it?
LTA (Laryngeal tracheal anesthetic)

Tube inserted into airway that releases a circumferential spray of lidocaine to the larynx and trachea just prior to intubation to decrease risk of airway irritation and bronchospasm
What other elements might you want to consider in your differential diagnosis of intraop bronchospasm?
Kink in tube, inadequate concentration of anesthetic drugs, Aspiration, pneumothorax, pulmonary embolism
What are the first three things you want to do if your patient experiences an intraoperative bronchospasm?
1. Increase volatile agent
2. Albuterol MDI
3. Corticosteroids
(consider theophylline if these do not work, but be aware of very narrow therapeutic index)
What is the best choice of volatile agent in your patient with Asthma?
Which volatile might you want to avoid?
Sevoflurane

Desflurane
Can you give succinylcholine to asthmatics?
Yes, despite Histamine release.
What drugs do you want to avoid giving Asthmatics?
Aspirin, NSAIDs, Tagamet, Beta Blockers
Cromolyn Sodium
Mast cell stabilizer, used to prevent asthma exacerbations
When are corticosteroids used with asthmatics?
Can be used for both acute and chronic treatment
What do beta sympathomimetics do in the treatment of asthma?
Causes bronchodilation
Ipratroprium Bromide is useful for:
exercise or irritant triggered asthma
Chronic bronchitis: diagnostic features?

Pink Puffer or blue bloater?
Productive cought on most days of a three consecutive month period every year for 2 years

Blue Bloater
What happens to the Residual Volume and Total Lung Capacity in someone with Chronic Bronchitis?
Is dyspnea an early or late sign?
RV increases, TLC remains the same; often have significant disease before dyspnea begins to occur
What effect does Chronic bronchitis have on the heart?
RV failure and Cor Pulmonale
Emphysema is characterized by

Pink Puffer or blue bloater?:
Loss of elastic recoil of the lungs, collapse of airways during exhalation
Pink Puffer
What spirometric changes would you expect in a patient with emphysema?
Increased RV, TLC, FRC, RV/TLC ration
Dominant feature of COPD is:
Progressive airflow obstruction
Typical appearance of someone with chronic bronchitis:
Overweight, dusky/cyanotic, pronounced cough, large sputum production, likely to have cor pulmonale, more cough than dyspnea, 40-55 years of age, frequent URI
Typical appearance of someone with emphysema:
Thin, pursed lip breathing, anxious, Non-cyanotic, pronounced dyspnea, minimal cough, low sputum production, infrequent URI, 50-75, Cor Pulmonale Rare
Pre-op management of someone with COPD should be aimed at:
determining the severity of disease, identifying treatments to decrease airway inflammation, treating infection, and increasing the size of small airways (reverse hypoxia, hydrate to decrease secretion tenacity)
Preoperative education for a patient with a history of COPD undergoing a thoracic or upper abdominal surgery should include:
Likelihood of post-op ventilation
What might Nitrous Oxide cause in a patient with COPD?
Increased air-trapping and potential for pneumothorax
Can you use PEEP in a patient with COPD
Yes, in moderation
Patients with COPD might be very _____ to narcotics
Sensitive to respiratory depressant effects- use caution and moderation so that you don't knock out their respiratory drive
If a COPD patient has and FEV <_____ and an upper abd or thoracic procedure, they are likely to _____.
50, remain intubated postoperatively
Name 6 examples of acute intrinsic restrictive lung disease
1. Pulmonary Edema
2. Opioid overdose
3. ARDS
4. Aspiration
5. High Altitude
6. CHF
Name 2 examples of chronic intrinsic restrictive lung disease
1. Sarcoidosis (cause uncertain, perhaps autoimmune and treated with steroids)
2.Drug induced pulmonary fibrosis
If a patient has sarcoidosis, they may need:
Stress dose steroids intraoperatively (especially if they have been treated with steroids in the past 6 months)
Name 10 examples of extrinsic restrictive lung disease
1. Obesity
2. Pregnancy
2. Kyphoscoliosis
4. Mediastinal mass
5. Chest wall or sternal deformities
6. Flail Chest
7. Pneumothorax
8.Pleural effusion
9. Neuromuscular disorders
10. Ascites
Preoperative management of a patient with acute intrinsic lung disease should include:
Maximize oxygenation and ventilation, treat volume overload
Intraoperative ventilator management of a patient with acute intrinsic lung disease might include
High FiO2, high PEEP, PC mode might be preferred (or VC with decreased TV and compensatory increase in rate)
Pre-operative assessment and management of a patient with chronic intrinsic or extrinsic lung disease might include:
Determine level of pulmonary impairment and dyspnea with exertion
Patients with restrictive lung disease are prone to ______ hypoxia
Very rapid onset, low pulmonary reserve before decompensation takes place
What 6 risk factors highly predispose postop respiratory complications (including post-op mechanical ventilation)?
1. Pre-existing pulmonary disease
2. Smoking
3. Upper abdominal or thoracic surgery
4.Obesity
5. Age > 60
6. Prolonged General anesthesia (case >2.5 hours)
the absorption, distribution, metabolism and excretion of inhaled or injected drugs
Pharmacokinetics
Volume of Distribution (Vd)
Dose of drug administered IV divided by the plasma concentration
Vd does not refer to absolute anatomic volumes. What does it represent?
the compartments that constitute the compartment model for that drug
Drugs with high concentrations in the central compartment have a _____ volume of distribution
low
Drugs with a high concentration in the peripheral compartment have a _____ volume of distribution
high
What two factors make a drug have a low volume of distribution (stay in central compartment)
Low lipid solubility, high degree of ionization
If a drug has a low volume of distribution, its concentration in the plasma will be _____.
High
Drugs that are lipid soluble and not ionized have a _____ volume of distribution, and therefore ______.
High, readily move into the peripheral compartment
Drugs that have a high volume of distribution have a ____ concentration in the central compartment, and a high concentration in the peripheral compartment.
Low in central, high in peripheral
Pharmacodynamics
the responsiveness of receptors to drugs and the mechanism by which these effects occur (what the drug does to the body)
Receptors
Specific macromolecules in cell membranes, "lock and key" mechanism that causes a reaction to take place
The number of receptors is ____ and can be _____ or _____ depending on stimuli.
Dynamic, can be upregulated or downregulated
Receptors work by ____
1. regulating production of cAMP
2. Opening or closing ion channels
3. Causing enzyme production
Patients on longstanding blood pressure medications have_____ receptors
More (due to upregulation)
If patients on long term blood pressure medications do not take these medications before surgery, they will have an _________ due to________
Exaggerated Response and become exceedingly hypertensive, due to up regulation of these receptors
IV drips are designed to maintain a _____ of drug filling receptors
steady state; plasma concentration is proportional to amount of drug at receptors
Factors (pharmacodynamics) that influence plasma concentrations of the drug will also influence the ______. This means that if drug delivery exceeds ______ the drug will accumulate
concentration at receptors; of delivery exceeds clearance, drug will accumulate in the body
volume of plasma cleared of drug by renal excretion and/or metabolism in the liver or other organs
Clearance
Most important organs for clearance of unchanged drugs and their metabolites
Kidneys; excrete water soluble drugs and/or their metabolites
Lipid soluble drugs must be____ before being excreted by the kidneys
Metabolized into water soluble drugs for excretion
Microsomal Enzymes to metabolize drugs are located in ______
hepatic smooth endoplasmic reticulum
The p450 enzyme system is important because
It can be excited or ramped up by having to clear chronic meds like dilatin, and can then metabolize other drugs more rapidly than usual
Elimination Half-Time
Time necessary for the plasma concentration of drug to decline 50% during the elimination phase
_____ elimination half-times are necessary for almost complete excretion of drug
Five
_____ drug is pharmacologically active and lipid soluble
Non-ionized
_____ drug is pharmacologically inactive and water soluble'
Ionized
Degree of ionization of a drug in the body is determined by its ___ and the ___ of the surrounding fluid
pKa, pH of the body or surrounding fluid
Changes in body ___ can effect the way drugs act within the body
pH
Oral drugs undergo a ____. What does this mean?
First-pass effect; oral drugs are metabolized extensively by the liver before having a chance to act upon the body
Redistribution
Transfer of drug to inactive tissue sites such as skeletal muscle
MAC
Minimum alveolar concentration (partial pressure) of an inhaled anesthetic at 1 atmosphere that prevents skeletal muscle movement in response to a noxious stimulus (surgical skin incision) in 50% of patients
Factors that reduce the number of MAC the patient will require
Most things that slow your brain down or make patients have altered LOC
Age extremes
•Hypothermia
•Metabolic acidosis
•Hypoxemia
•Hypotension
•Preoperative Medications
•IV anesthetics
•Alpha-2 agonists, Lithium, Opioids
•Cardiopulmonary bypass
•MAP <40 mmHg
•PaO2 <38 mmHg
•Hypothyroidism
•Pregnancy – Postpartum (<72 hours)
•Acute ethanol consumption
Factors that increase the number of MACs the patient will require
Pretty much anything very stimulating
•Hyperthermia
•Hypernatremia
•Chronic alcohol consumption
•Infants
•Drugs that increase CNS catecholamines (MAOI, tricyclic antidepressants, cocaine, acute amphetamine ingestion)
MAC
Minimum alveolar concentration (partial pressure) of an inhaled anesthetic at 1 atmosphere that prevents skeletal muscle movement in response to a noxious stimulus (surgical skin incision) in 50% of patients
Factors that have no effect on the MAC that the patient will require
•Duration of anesthesia
•Gender
•Hypo or hypercarbia
•Hypertension
•Anesthetic metabolism
•Thyroid gland dysfunction
•Hypo or hyperkalemia
•PaO2 >38mmHg
•Spinal cord transection/removal of forebrain in animals
The Myer-Overton Theory (or Critical Volume Hypothesis)
Anesthesia occurs when a critical volume of anesthetic molecules dissolve in crucial lipid soluble (hydrophobic) sites such as cell membranes, resulting in external pressure on ion channels necessary for sodium movement across membranes
Factors that reduce the number of MAC the patient will require
•Increase in age- Most things that slow your brain down or make patients have altered LOC
•Hypothermia
•Metabolic acidosis
•Hypoxemia
•Hypotension
•Preoperative Medications
•IV anesthetics
•Neonates
•Alpha-2 agonists, Lithium, Opioids
•Cardiopulmonary bypass
•MAP <40 mmHg
•PaO2 <38 mmHg
•Hypothyroidism
•Pregnancy – Postpartum (<72 hours)
•Acute ethanol consumption
Factors that increase the number of MACs the patient will require
Pretty much anything very stimulating
•Hyperthermia
•Hypernatremia
•Chronic alcohol consumption
•Infants
•Drugs that increase CNS catecholamines (MAOI, tricyclic antidepressants, cocaine, acute amphetamine ingestion)
Factors that have no effect on the MAC that the patient will require
•Duration of anesthesia
•Gender
•Hypo or hypercarbia
•Hypertension
•Anesthetic metabolism
•Thyroid gland dysfunction
•Hypo or hyperkalemia
•PaO2 >38mmHg
•Spinal cord transection/removal of forebrain in animals
The Myer-Overton Theory (or Critical Volume Hypothesis)
Anesthesia occurs when a critical volume of anesthetic molecules dissolve in crucial lipid soluble (hydrophobic) sites such as cell membranes, resulting in external pressure on ion channels necessary for sodium movement across membranes
Which is more potent, a lipid soluble inhaled anesthetic, or a water soluble anesthetic?
Lipid- high degree of correlation between inhaled anesthetic potency and lipid solubility (part of Myer-Overton Theory)
What three molecular mechanisms are believed to be responsible for the action of general anesthetics?
•Bind directly to proteins
•Selectively target synaptic ion channels or the systems that regulate them
•Enhance the response evoked by GABA
What effect do inhaled anesthetics have on respiratory patterns?
Breathing will be rapid, shallow, regular, and rhythmic
Do inhaled anesthetics increase or decrease respiratory rate? What effect do they have on Tidal Volume?
Increase rate (dose dependent), decrease Tidal Volume
What effect do inhaled anesthetics have on PaCO2? What other factor influences this intraoperatively?
Increase PaCO2; surgical stimulation also influences this
Inhaled anesthetics cause a _________ to the effects of increased CO2?
Decreased response; increased CO2 level does not make anesthetized patients increase their rate or depth of breathing
Anesthetic concentrations of _______ will completely eliminate the regular respiratory response to _______.
1 MAC, eliminate normal response to hypoxemia
sub anesthetic concentrations of inhaled anesthetics (less than 1 MAC) have what impact on the normal response to hypoxemia?
Decreased, but not obliterated response to hypoxemia
How long might the decreased ventilatory response to hypoxemia caused by inhaled anesthetics last?
Well into their time in the PACU
What effect to inhaled anesthetics have on bronchial smooth muscle?
Relaxes, causing Bronchodilation
What two anesthetic agents are known to be more airway irritating?
Forane and desflurane
What are the inhaled anesthetic drugs held to be the standard for being non airway irritating?
Sevoflurane, halothane, and N2O
Under the effects of inhaled anesthetics, is the pulmonary vasoconstriction response to hypoxemia preserved?
Yes, pulmonary arterioles will still vasoconstrict in response to hypoxemia
What effect do inhaled anesthetics have on blood pressure?
What can attenuate this response?
Decreased blood pressure; surgical stimulation and addition of N2O decrease this response
Why do inhaled anesthetics cause a decrease in blood pressure?
Decreased SVR
Normally a decrease in BP will stimulate _________ resulting in an increase in heart rate.
Carotid sinus baroreceptors
What effect does Sevoflorane have on heart rate?
No effect
N2O results in a _____ in heart rate
Mild increase
At levels less than 1 MAC, what effect does desflurane have on HR?
No effect
At levels greater than 1 MAC, what effect does desflurane have on HR?
Increases
In response to a decrease in blood pressure, Halothane _____
Blocks the normal carotid sinus baroreceptor response that increases HR- i.e. HR not responsive to hypotension
With sevoflurane, does the heart rate increase in response to hypotension? With N2O?
No,
N20 causes minimal increase
What effect does decreasing blood pressure have on heart rate when using desflurane?
No effect at concentrations less than 1 MAC, Heart rate increases at greater MAC concentrations
What effect does decreased blood pressure have on heart rate when using isoflorane?
Increases 20%
Halothane causes a dose dependent _____ in cardiac output
Decrease
Desflurane and Isoflurane have ______ effect on cardiac output
No effect
What inhaled anesthetic will support cardiac index the best?
Desflurane
What effect does N20 have on cardiac output? What effect does it have on stroke volume?
Increases it slightly, no effect on stroke volume
Agents other than N20 cause a_______ on stroke volume
Dose dependent decrease in stroke volume
Considering the decrease in stroke volume, does using isoflurane or desflurane result in decreased cardiac output?
No; increase in heart rate compensates for decrease in stroke volume, and CO is unchanged
Is a direct decrease in myocardial contractility with inhaled anesthetics seen in practice?
No, not consistently seen in reality, although it is theoretically possible
What inhaled agent has the least effect on myocardial contractility?
N20
Right Atrial Pressure _____ in a dose dependent manner when using inhaled anesthetics
Increases- d/t myocardial depression
The increase in R. Atrial Pressure d/t myocardial depression is _____ by any peripheral dilating effect caused by inhaled agents
attenuated/offeset
_____ and ____ (agents) cause a decrease in SVR
Isoflurane and Desflurane
Halothane and N20 have ___ effect on SVR
No effect
Addition of N20 to ___ and ____ results in less decrease in ___
Isoflurane and Desflurane results in less reduction in SVR
______ selectively dilates coronary arteries in animal studies
Isoflurane
Coronary Steal Syndrome:
What is it, and what agent is thought to cause it?
Coronary dilation causes a decrease in blood flow through narrowed coronary arteries (which are attempt to compensate by always being maximally dilated); could possibly be caused by Isoflurane (this could result in ischemia, although autoregulation seems to compensate)
Anesthetics sensitize the myocardium to the effects of ____
Epi (use less epi than in ICU setting)
______ rhythm is common during administration of inhaled anesthetics
Junctional rhythm
Which agent causes the least effect on cardiac rhythm?
Sevoflurane (Halothane causes most, followed by ethrane, isoflurane, desflurane, and finally sevoflurane)
You should not administer N20 to a patient with this type of pulmonary blood flow
Pulmonary hypertension- N20 increases Pulmonary vascular resistance and can worsen pulmonary HTN
________ ventilation favors venous blood return to the heart
spontaneous
Increased duration of anesthetic administration results in _____ depressant effects with which agents
less, halothane, ethrane, desflurane
Patients with ____ will have increased anesthetic induced myocardial depression
CHF
_____ and _____ will produce myocardial depression
CAD and N20
_______ will exaggerate the magnitude of circulatory effects produced by inhaled anesthetics
Altered SNS/prior drug therapy (for example beta blockers, other blood pressure medications)
Surgical stimulation causes _____
SNS activation
What is a potential side effect caused by Halothane? Why did it have this effect?
Halothane Hepatitis; halothane metabolized by liver, thought to be autoimmune caused by circulating IGG antibodies
Isoflurane, desflurane, and enflurane may cause
Hepatotoxic metabolites in susceptible individuals (such as those with previous exposure to halothane)
Methoxyflurane and ____ could cause_____ if metabolism leads to a serum fluoride level greater than 50 mcmol/L
Sevoflurane, Fluoride induced nephrotoxicity- leads to inability to concentrate urine
Is there any evidence that anesthetic administration during pregnancy is teratogenic?
No evidence for most agents, avoid N2O d/t concerns of teratogenicity
Pbr =
partial pressure of inhaled agent in brain = input (into alveoli) - uptake (lost into arterial blood)
Input (of agent into alveoli) is dependent on what 3 factors?
•Inspired partial pressure of the anesthetic (PI)
•Alveolar ventilation (VA)
•Characteristics of the anesthetic breathing system
Uptake from alveoli into blood is dependent on:
•Solubility of the agent
•Cardiac output
•Alveolar to venous partial pressure difference (A-vD)
Does metabolism or percutaneous loss impact PA of inhaled anesthetics?
No
Second Gas Effect:
Is this impacted by concentration effect?
The ability of the large volume uptake of one gas (first gas) to accelerate the rate of rise of the PA of a concurrently administered companion gas (second gas); independent of concentration effect (probably not clinically significant)
What effect does increased alveolar ventilation have on input of inhaled agents?
Increased alveolar ventilation increases input of agents; increases PA of inhaled agents and promotes more rapid induction of anesthesia (hypoventilation has opposite effect)
What effect does hyperventilation have on input of anesthetics?
Increases input, but decreases cerebral bloodflow and therefore offsets effect by decreasing delivery to brain
Partition Coefficient
Solubility; Distribution ratio describing how the inhaled anesthetic distributes itself between two phases at equilibrium
What factor affects partition coefficient?
Temperature dependent
High blood solubility (blood partition coeffient) means that a _____ amount of agent needs to be dissolved in blood before equilibrium is reached (works _____)
Large, slowly
Drugs with a high blood solubility take a ______ time for patient to go to sleep and wake up
Long
Low blood solubility means that ____amount needs to be dissolved in blood before equilibrium is reached (works _____)
small, fast
Drugs with a _____ blood gas partition coefficient will take less time for the anesthetic concentration in the brain to reach the concentration of anesthetic in the alveoli
Low
maintaining the pressure in the alveoli for volatile anesthetics constant for about ______ will assure an equal concentration in the brain
15 minutes (predicted by tissue blood coefficients)
N20 has a lower blood gas partition coefficient than Nitrogen. Therefore, N20 can _____ air filled spaces faster than Nitrogen can leave, resulting in an increased ____ or ____ in air filled cavities
Enter, causing increase in volume or pressure
The magnitude of volume or pressure increase is influenced by the _____, ______, and the ____ of nitrous oxide administration
Alveolar pressure of N20, blood flow to air filled space, and duration of N20 administration
Cardiac output influences _____. Therefore, patients with high cardiac output will go to sleep ____than patients with low cardiac output
Slower
A right-to-left intracardiac or intrapulmonary shunt _____ the rate of induction of anesthesia. Why?
Slows; dilutional effect
Highly perfused tissues _____ with the arterial concentration of the volatile anesthetic
equilibrate rapidly
Skeletal muscle and fat receive less cardiac output than highly perfused organs, and serve as a ______ for volatile agents
Inactive reservoir
What three things are produced in response to stress (such as surgery?)
Glucagon, catecholamines, Cortisol
What is the primary and most important regulatory mechanism of hormone secretion?
Feedback mechanisms (others are biorhythms and neural controls, but less important)
The pituitary gland is enclosed in the _____ and connected by the _______.
Sella Turcica, hypophyseal stalk
Hormones of the anterior pituitary
FLAGTOP
Follicle stimulating
Luteinizing
ACTH
Growth hormone
thyroid stimulating hormone
MelanOcyte stimulating hormone
Prolactin
Patients with Acromegaly are at high risk for
difficult airway and post-op airway obstruction- consider awake fiberoptic intubation/glidescope
Posterior pituitary hormones
ADH (vasopressin) and oxytocin
DI is caused by ____ and leads to _____
Lack of ADH (damage to pituitary) or kidney not responsive to ADH; leads to excessive diuresis of straight water and hypernatremia
SIADH is caused by _____ and leads to______. Treated by:
Overproduction of ADH, straight water retention, dilutional hyponatremia. Treat with fluid restriction, diuretics, hypertonic saline
4 functions of the thyroid:
1.carbohydrate and lipid metabolism
2. maintain metabolism
3. stimulate oxygen consumption
4.secrete calcitonin
Which is more active, T3 or T4?
More T4, but T3 more potent
Hyperthyroidism: _____ disease
Graves disease
(exopthalmos, increased metabolic rate with associated S/S)
Graves disease treatment:
radioactive iodine, thyroidectomy, beta blockade (to block extra SNS stimulation)
NEM tube:
monitors if surgeon is too close to recurrent laryngeal nerve
In a patient with hyperthyroidism, you want to avoid_______
Ketamine (SNS stimulant)
For a hypotensive patient with hyperthyroid, you want to give
Direct acting vasoconstrictors
Close airway assessment of a patient with hyperthyroid may be very important due to
Goiters
Thyroid surgery can result in
Recurrent laryngeal nerve damage (vocal cord paresis)- may want to use NIM tube to monitor, or tracheal compression
Patients may have what airway complications after thyroid surgery?
Stridor and laryngospasm
Differential diagnosis for intraoperative thyroid storm would include:
How would you treat it?
Malignant hyperthermia (s/s very similar); hyperthermia, tachycardia, dysrhythmias, CHF; give anti-thyroid meeds, fluids, control temperature, control HR (esmolol)
In hyperparathyroidism, iCa is usually ______
very high; want to normalize pre-op with fluids and diuretics
Hypoventilation should be avoided in patients with hyperparathyroid because_____
Hypercarbia can increase calcium level
Response to NDMR in hyperparathyroidism?
Unpredictable (based on calcium levels)
Aldosterone (mineralocorticoid):

What causes its release
regulation of extracellular causes potassium excretion and sodium retention; results in increased blood volume and fluid retention
Adrenal cortex releases:
mineralo and corticosteroids (aldosterone and cortisol) and androgens
Adrenal medulla releases
Catecholamines (epi, norepi, dopamine)
Conn's Tumor
Primary aldosteronism- causes excess effect (HTN, hypokalemia, fluid retention); give spironolactone,
NDMB can be unpredictable because of hypokalemia
Proper positioning of a patient with Cushing's disease is especially important because:
of risk for osteoporosis
Conn's Tumor
Primary aldosteronism- causes excess effect (HTN, hypokalemia, fluid retention); give spironolactone,
NDMB can be unpredictable because of hypokalemia
Proper positioning of a patient with Cushing's disease is especially important because:
of risk for osteoporosis
Strict aseptic technique is especially important for patients with:
Cushin's disease (immunocompromised)
Strict aseptic technique is especially important for patients with:
Cushin's disease (immunocompromised)
Addison's Disease:
Adrenal corticoid deficiency (hypovolemia, hyponatremia, hyperkalemia, hypoglycemia, hypotension)
Conn's Tumor
Primary aldosteronism- causes excess effect (HTN, hypokalemia, fluid retention); give spironolactone,
NDMB can be unpredictable because of hypokalemia
Addison's Disease:
Adrenal corticoid deficiency (hypovolemia, hyponatremia, hyperkalemia, hypoglycemia, hypotension)
Any patient who has received steroids for more than 2 weeks out of the last 12 months should receive
Stress dose steroids (Addisonian crisis can result if not given)
Proper positioning of a patient with Cushing's disease is especially important because:
of risk for osteoporosis
Conn's Tumor
Primary aldosteronism- causes excess effect (HTN, hypokalemia, fluid retention); give spironolactone,
NDMB can be unpredictable because of hypokalemia
Any patient who has received steroids for more than 2 weeks out of the last 12 months should receive
Stress dose steroids (Addisonian crisis can result if not given)
Strict aseptic technique is especially important for patients with:
Cushin's disease (immunocompromised)
Conn's Tumor
Primary aldosteronism- causes excess effect (HTN, hypokalemia, fluid retention); give spironolactone,
NDMB can be unpredictable because of hypokalemia
Proper positioning of a patient with Cushing's disease is especially important because:
of risk for osteoporosis
Addison's Disease:
Adrenal corticoid deficiency (hypovolemia, hyponatremia, hyperkalemia, hypoglycemia, hypotension)
Strict aseptic technique is especially important for patients with:
Cushin's disease (immunocompromised)
Proper positioning of a patient with Cushing's disease is especially important because:
of risk for osteoporosis
Conn's Tumor
Primary aldosteronism- causes excess effect (HTN, hypokalemia, fluid retention); give spironolactone,
NDMB can be unpredictable because of hypokalemia
Addison's Disease:
Adrenal corticoid deficiency (hypovolemia, hyponatremia, hyperkalemia, hypoglycemia, hypotension)
Any patient who has received steroids for more than 2 weeks out of the last 12 months should receive
Stress dose steroids (Addisonian crisis can result if not given)
Strict aseptic technique is especially important for patients with:
Cushing's disease (immunocompromised)
Proper positioning of a patient with Cushing's disease is especially important because:
of risk for osteoporosis
Addison's Disease:
Adrenal corticoid deficiency (hypovolemia, hyponatremia, hyperkalemia, hypoglycemia, hypotension)
Strict aseptic technique is especially important for patients with:
Cushin's disease (immunocompromised)
Any patient who has received steroids for more than 2 weeks out of the last 12 months should receive
Stress dose steroids (Addisonian crisis can result if not given)
Addison's Disease:
Adrenal corticoid deficiency (hypovolemia, hyponatremia, hyperkalemia, hypoglycemia, hypotension)
Any patient who has received steroids for more than 2 weeks out of the last 12 months should receive
Stress dose steroids (Addisonian crisis can result if not given)
Any patient who has received steroids for more than 2 weeks out of the last 12 months should receive
Stress dose steroids (Addisonian crisis can result if not given)
Conn's Tumor
Primary aldosteronism- causes excess effect (HTN, hypokalemia, fluid retention); give spironolactone,
NDMB can be unpredictable because of hypokalemia
Proper positioning of a patient with Cushing's disease is especially important because:
of risk for osteoporosis
Strict aseptic technique is especially important for patients with:
Cushin's disease (immunocompromised)
Addison's Disease:
Adrenal corticoid deficiency (hypovolemia, hyponatremia, hyperkalemia, hypoglycemia, hypotension)
Any patient who has received steroids for more than 2 weeks out of the last 12 months should receive
Stress dose steroids (Addisonian crisis can result if not given)
Conn's Tumor
Primary aldosteronism- causes excess effect (HTN, hypokalemia, fluid retention); give spironolactone,
NDMB can be unpredictable because of hypokalemia
Proper positioning of a patient with Cushing's disease is especially important because:
of risk for osteoporosis
Strict aseptic technique is especially important for patients with:
Cushing's disease (immunocompromised)
Conn's Tumor
Primary aldosteronism- causes excess effect (HTN, hypokalemia, fluid retention); give spironolactone,
NDMB can be unpredictable because of hypokalemia
Addison's Disease:
Adrenal corticoid deficiency (hypovolemia, hyponatremia, hyperkalemia, hypoglycemia, hypotension)
Any patient who has received steroids for more than 2 weeks out of the last 12 months should receive
Stress dose steroids (Addisonian crisis can result if not given)
Proper positioning of a patient with Cushing's disease is especially important because:
of risk for osteoporosis
Strict aseptic technique is especially important for patients with:
Cushin's disease (immunocompromised)
Addison's Disease:
Adrenal corticoid deficiency (hypovolemia, hyponatremia, hyperkalemia, hypoglycemia, hypotension)
Any patient who has received steroids for more than 2 weeks out of the last 12 months should receive
Stress dose steroids (Addisonian crisis can result if not given)
How would you treat Addisonian crisis?
Rapid administration or D5NS
Hydrocortisone bolus
Hydrocortisone q6
Pheochromacytoma
Catecholamine secreting tumor
Pheochomocytomoa: order of adrenergic blocking
Block alpha before beta adrenergics (otherwise, can increase BP even further)
After ligation of vasculature feeding pheo, blood pressure:
Falls rapidly (due to down regulation of adrenergic receptors), and not likely to normalize for 10 days
Patients with DM are at increased risk for:
Undiagnosed cardiac issues
Also may have TMJ, gastroparesis (at risk for aspiration)
Sulfonylureas: what do they do?
Decrease insulin resistance and increase release from the pancreas for 8-24 hours
Sulfonylureas should be _____ on the day of surgery
Held
Diabetic autonomic neuropathy puts patients at increased risk for:
(silent) MI, ischemia, labile BP, cardiomyopathy
What is a reliable indicator for autonomic neurophathy in diabetic patients?
Orthostatic hypotension
Diabetics are more likely to have a _____ allergy
Protamine (d/t long term exposure to NPH insulin)
Management goal for blood sugars intraoperatively is
below 180
Why are patients prone to hyperglycemia intraoperavtiely?
Decreased insulin release, increased catecholamines, increased cortisol. glucagon, and growth hormone
S/S of diabetic autonomic neuropathy:
early satiety, impotence, night time diarrhea, peripheral neuropathy, loss of beat to beat variability in HR, orthostatic hypotension, unexplained tachycardia
Myocardial O2 demand is most significantly affected by:
Heart rate
What types of surgery put patients at highest risk of cardiac event?
Major abdominal, thoracic, and emergency surgeries
Blood pressure should be maintained within _____ of baseline values?
20%
What is one treatment goal for patients with cardiac disease during induction?
Blunt the sympathetic response to DL (narcotics, LTA, IV lidocaine, esmolol)
What is a good combination for cardiac anesthesia?
Opioid and Nitrous
What anesthetic technique should be avoided with critical aortic stenosis?
regional anesthesia
What NDMB might cause increased HR and BP?
Pavulon
Risk of re-infarction after MI remains for ____ months and is highest for the first ____ months
6 months; highest risk for first 3 months
Patients with drug eluting stents must not stop plavix for the first ____, and elective surgeries should be delayed
12 months
Patients with bare metal stents should not have elective surgery in the first____ after placement
6 weeks
Cystoscopy is performed in what position? What impact does this have on your FRC?
Lithotomy, decreases FRC
TURP (transurethral resection of prostate): why is so much fluid instilled?
To provide visualization through cystoscope
If you have a perforation of your bladder or urethra during a TURP procedure, where would pain be referred to?
Shoulder
What are the risks of TURP procedure?
◦Intravascular absorption of irrigating fluid.
◦Hemorrhage
◦Perforation of bladder or urethra.
Why does a patient absorb irrigation fluid in a TURP procedure?
Opening of venous sinuses allows entry into the vascular system
The amount of fluid absorbed during a TURP procedure is dependent on:
◦ Height of irrigating fluid
◦Number and size of venous sinuses opened.
◦Duration of resection
What fluids are used for irrigation in a TURP procedure?
Glycine and Cytal
Why is it important to monitor the instilled versus drained irrigation fluid in a TURP procedure?
dilutional hyponatremia can result; if patient is awake (regional), monitor LOC closely (headache, loopy,
Glycine toxicity in a TURP procedure causes:
Glycine is broken down to ammonia, which can act as a CNS depressant; glycine is also a neurotransmitter in the retina, so glycine toxicity can also lead to transient blindness
An early sign that you might be getting into trouble during a TURP (except LOC changes)
Hypertension and reflex bradycardia
Resection time for a TURP should be limited to
1 hour
Fluid can be absorbed during a TURP at a rate of
20ml/min
What is one consideration regarding airway issues during robotic prostatectomy?
Extreme trendeleberg- can cause ETT migration (high or out) so make sure taped super securely; can cause difficulty ventilating
Extreme head down positioning can cause:
initial increase in cardiac output followed by decreased cardiac output, edema to head, face, and airway (laryngeal edema, post-op stridor) risk of pneumothorax, carbon dioxide embolism (from insufflation),
co2 insufflation in the peritoneum may result in:
hypercaria, acidosis if not compensated for by respiratory system, hypertension (from SNS stimulation and Aldosterone release); increased intraabdominal pressure
In mitral stenosis, you want the heart rate to be ____, SVR to be ____, preload _____, and contractility ______
low HR, SVR maintained, preload maintained to slightly increased, contractility maintained
Mitral regurg- memory aid
Fast, full, and forward
What vasopresor might you want to use in a patient with mitral regurg and hypotension
Ephedrine is better choice than phenylephrine because it increases HR
In Aortic stenosis, the stroke volume is _____
fixed
Heart rate in aortic stenosis should be _____, preload should be ____, and after load should be_____
Heart rate low (70-80), preload and after load maintained or increased, and contractility maintained
(Neo is good vasopressor in this disease)
Aortic Regurg:
Fast, full, and forward (HR 80-100, increase preload, decrease after load)
With hypertrophic cardiomyopathy, what would be the best agent to use in the case of vasodilation?
Phenylephrine (pure alpha 1 agonist)
Would you do a spinal in a patient with hypertrophic cardiomyopathy?
No, d/t too much change in preload and after load
Patients with artificial valves, shunts, or a history of endocarditis should receive _______
prophylactic antibiotics for any procedure where bleeding is anticipated
Where should the bovie ground pad be placed on a patient with an AICD?
As far from the AICD as possible
AICD should be _____ prior to surgery because
turned off, d/t potential interference from bovie
Placing a magnet over the AICD
Disables the ICD, and paces at a set rate; resumes to normal when magnet removed