Surgical Recall: 65 - Surgical Intensive Care

Front 1

How is an ICU note written?

Back 1

By systems:

- Neuro: GCS, MAE, pain control

- Pulmonary: vent settings

- CV: pressors, Swan numbers

- GI

- Heme: CBC

- FEN: Chem 10, nutrition

- Renal: urine output, BUN, Cr

- ID: Tmax, WBC, antibiotics

- Assessment

- Plan

Note: physical exam is included in each section

Front 2

What is the best way to report urine output in the ICU?

Back 2

24 hours / last shift / last 3 hourly rate:

"Urine output has been 2L over last 24 hours, 350 last shift, and 45/35/40cc over last 3 hours"

Front 3

What are the possible causes of fever in ICU?

Back 3

- Central line infection

- PNA/atelectasis

- UTI, urosepsis

- Intra-abdominal abscess

- Sinusitis

- DVT

- Thrombophlebitis

- Drug fever

- Fungal infection, meningitis, wound infection

- Endocarditis

Front 4

What is the most common bacteria in ICU pneumonia?

Back 4

Gram negative rods

Front 5

What is the acronym for the basic ICU care checklist?

Back 5

FAST HUG:

- Feeding

- Analgesia

- Sedation

- Thromboembolic prophylaxis

- Head of bed elevation (pneumonia prevention)

- Ulcer prevention

- Glucose control

Front 6

What is CO?

Back 6

Cardiac output = HR * Stroke Volume

Front 7

What is the normal CO?

Back 7

4-8 L/min

Front 8

What factors increase CO?

Back 8

- Increased contractility, HR, and preload

- Decreased afterload

Front 9

What is CI?

Back 9

Cardiac Index = CO/BSA (body surface area)

Front 10

What is the normal CI?

Back 10

2.5-3.5 L/min/m^2

Front 11

What is SV?

Back 11

Stroke Volume = the amount of blood pumped out of the ventricle each beat; simply, end diastolic volume minus the end systolic volume or CO/HR

Front 12

What is the normal stroke volume?

Back 12

60-100 cc

Front 13

What is CVP?

Back 13

Central Venous Pressure = indirect measurement of intravascular volume status

Front 14

What is the normal CVP?

Back 14

4-11

Front 15

What is PCWP?

Back 15

Pulmonary Capillary Wedge Pressure = indirectly measures left atrial pressure, which is an estimate of intravascular volume (LV filling pressure)

Front 16

What is the normal PCWP?

Back 16

5-15

Front 17

What is anion gap?

Back 17

Na+ - (Cl- + HCO3-)

Front 18

What are the normal values for anion gap?

Back 18

10-14

Front 19

Why do you get an increased anion gap?

Back 19

Unmeasured acids are unmeasured anions in the equation that are part of the "counterbalance to the sodium cation

Front 20

What are the causes of increased anion gap acidosis in surgical patients?

Back 20

"SALUD":

- Starvation

- Alcohol (ethanol/methanol)

- Lactic acidosis

- Uremia (renal failure)

- DKA

Front 21

What is MODS?

Back 21

Multiple Organ Dysfunction Syndrome

Front 22

What is SVR?

Back 22

Systemic Vascular Resistance = MAP - CVP / CO * 80

Remember, P = F*R

Front 23

What is SVRI?

Back 23

Systemic Vascular Resistance Index: SVR / BSA (body surface area)

Front 24

What is the normal SVRI?

Back 24

1500-2400

Front 25

What is MAP?

Back 25

Mean Arterial Pressure = diastolic blood pressure + 1/3 (systolic - diastolic pressure)

Note: not the mean between diastolic and systolic BP because diastole lasts longer than systole

Front 26

What is PVR?

Back 26

Pulmonary Vascular Resistance = PA(mean) - PCWP / CO * 80

PA = pulmonary artery pressure and LA is left atrial or PCWP pressure

Front 27

What is the normal PVR value?

Back 27

100 ± 50

Front 28

What is the formula for arterial oxygen content?

Back 28

Hemoglobin * O2 saturation (SaO2) * 1.34

Front 29

What is the basic formula for oxygen delivery?

Back 29

CO * (oxygen content)

Front 30

What is the full formula for oxygen delivery?

Back 30

CO * (1.34 * Hgb * SaO2) * 10

Front 31

What factors can increase oxygen delivery?

Back 31

Increased CO by increasing SV, HR, or both; increased O2 content by increasing the Hgb content, SaO2, or both

Front 32

What is mixed venous oxygen saturation?

Back 32

SvO2 = simply the O2 saturation of the blood in the RV or pulmonary artery; an indirect measure of peripheral O2 supply and demand

Front 33

Which lab values help assess adequate oxygen delivery?

Back 33

- SvO2 (low with inadequate delivery)

- Lactic acid (elevated with inadequate delivery)

- pH (acidosis with inadequate delivery)

- Base deficit

Front 34

What is FENa?

Back 34

Fractional Excretion of Sodium (Na) = (Una * Pcr / Pna * Ucr) *100

Front 35

What is the memory aid for calculating FENa?

Back 35

YOU NEED PEE = U (urine) N (Na+) P (Plasma)

Una * Pcr

For the denominator switch everything:

Pna * Ucr

Front 36

What is the pre-renal FENa value?

Back 36

<1.0 = renal failure from decreased renal blood flow (eg, cardiogenic, hypovolemia, arterial obstruction, etc)

Front 37

How long does Lasix effect last?

Back 37

6 hours

Front 38

What is the formula for flow / pressure / resistance?

Back 38

P = F * R

Power FoRward

Front 39

What is the "10 for 0.08 rule" of acid base?

Back 39

For every increase of PaCO2 by 10 mmHg, the pH falls by 0.08

Front 40

What is the "40, 50, 60 for 70, 80, 90 rule" for O2 sats?

Back 40

PaO2 of 40, 50, 60 corresponds roughly to an O2 sat of 70, 80, 90, respectively

Front 41

1L of O2 via nasal canula raises FiO2 by how much?

Back 41

~3%

Front 42

What is pure respiratory acidosis?

Back 42

Low pH (acidosis), increased PaCO2, normal bicarb

Front 43

What is pure respiratory alkalosis?

Back 43

High pH (alkalosis), decreased PaCO2, normal bicarb

Front 44

What is pure metabolic acidosis?

Back 44

Low pH, low bicarb, normal PaCO2

Front 45

What is pure metabolic alkalosis?

Back 45

High pH, high bicarb, normal PaCO2

Front 46

How does the body compensate for respiratory acidosis?

Back 46

Increased bicarb

Front 47

How does the body compensate for respiratory alkalosis?

Back 47

Decreased bicarb

Front 48

How does the body compensate for metabolic acidosis?

Back 48

Decreased PaCO2

Front 49

How does the body compensate for metabolic alkalosis?

Back 49

Increased PaCO2

Front 50

What does MOF stand for?

Back 50

Multiple Organ Failure

Front 51

What does SIRS stand for?

Back 51

Systemic Inflammatory Response Syndrome

Front 52

What is the site of action and effect for dopamine at a low dose (1-3 µg/kg/min)?

Back 52

++ dopa agonist, renal vasodilation (aka renal dose dopamine)

Front 53

What is the site of action and effect for dopamine at a intermediate dose (4-10 µg/kg/min)?

Back 53

+ alpha-1, ++ beta-1, positive inotropy and some vasoconstriction

Front 54

What is the site of action and effect for dopamine at a high dose (>10 µg/kg/min)?

Back 54

+++ alpha-1 agonist, marked afterload increase from arteriolar vasoconstriction

Front 55

Has "renal dose" dopamine been shown to decrease renal failure?

Back 55

NO

Front 56

What is the site of action of dobutamine?

Back 56

+++ beta-1 agonist

++ beta-2 agonist

Front 57

What is the effect of dobutamine?

Back 57

- Increased inotropy

- Increased chronotropy

- Decrease in systemic vascular resistance

Front 58

What is the site of action of isoproterenol?

Back 58

+++ beta-1 agonist

+++ beta-2 agonist

Front 59

What is the effect of isoproterenol?

Back 59

- Increased inotropy

- Increased chronotropy

- Vasodilation of skeletal and mesenteric vascular beds

Front 60

What is the site of action of epinephrine?

Back 60

++ alpha-1 agonist

++ alpha-2 agonist

++++ beta-1 agonist

++++ beta-2 agonist

Front 61

What is the effect of epinephrine?

Back 61

Increased inotropy and chronotropy

Front 62

What is the effect of epinephrine at high doses?

Back 62

Vasoconstriction

Front 63

What is the site of action of norepinephrine?

Back 63

+++ alpha-1 agonist

+++ alpha-2 agonist

+++ beta-1 agonist

Front 64

What is the effect of norepinephrine?

Back 64

- Increased inotropy and chronotropy

- ++ Increase in BP

Front 65

What is the action of vasopressin?

Back 65

Vasoconstriction (increases MAP, SVR)

Front 66

What are the indications of vasopressin?

Back 66

Hypotension, especially refractory to other vasopressors (low-dose infusion - 0.01-0.04 units per minute) or as a bolus during ACLS (40 u)

Front 67

What is the site of action of nitroglycerine?

Back 67

+++ venodilation

+ arteriolar dilation

Front 68

What is the effect of nitroglycerine?

Back 68

- Increased venous capacitance

- Decreased preload

- Coronary arteriole vasodilation

Front 69

What is the site of action of sodium nitroprusside?

Back 69

+++ venodilation

+++ arteriolar dilation

Front 70

What is the effect of sodium nitroprusside?

Back 70

Decreased preload and afterload (allowing BP titration)

Front 71

What is the major toxicity of sodium nitroprusside?

Back 71

Cyanide toxicity

Front 72

What is preload?

Back 72

Load on the heart muscle that stretches it to end-diastolic volume (end-diastolic pressure) = intravascular volume

Front 73

What is afterload?

Back 73

Load or resistance the heart must pump against = vascular tone = SVR

Front 74

What is contractility?

Back 74

Force of heart muscle contraction

Front 75

What is compliance?

Back 75

Distensibility of heart by preload

Front 76

What is the Frank-Starling curve?

Back 76

Cardiac output increases with increasing preload up to a point

Front 77

What is the clinical significance of the steep slope of the Starling curve relating end diastolic volume to cardiac output?

Back 77

Demonstrates the importance of preload in determining cardiac output

Front 78

What factors influence the oxygen content of whole blood?

Back 78

Oxygen content is composed largely of that oxygen bound to hemoglobin, and is thus determined by the hemoglobin concentration and the arterial oxygen saturation; the partial pressure of oxygen dissolved in plasma plays a minor role

Front 79

What factors influence mixed venous oxygen saturation?

Back 79

Oxygen delivery (hemoglobin concentration, arterial oxygen saturation, cardiac output) and oxygen extraction by the peripheral tissues

Front 80

What lab test for tissue ischemia is based on the shift from aerobic to anaerobic metabolism?

Back 80

Serum lactic acid levels

Front 81

What is dead space?

Back 81

That part of the inspired air that does not participate in gas exchange (e.g., the gas in the large airways/ET tube not in contact with capillaries)

Think: space = air

Front 82

What is shunt fraction?

Back 82

That fraction of pulmonary venous blood that does not participate in gas exchange

Think: shunt = blood

Front 83

What causes increased dead space?

Back 83

- Overventilation (emphysema, excessive PEEP)

- Underperfusion (pulmonary embolus, low cardiac output, pulmonary artery vasoconstriction)

Front 84

At high shunt fractions, what is the effect of increasing FiO2 on arterial PO2?

Back 84

At high shunt fractions (>50%), changes in FiO2 have almost no effect on arterial PO2 because the blood that does “see” the O2 is already at maximal O2 absorption; thus, increasing the FiO2 has no effect (FiO2 can be minimized to prevent oxygen toxicity)

Front 85

Define ARDS?

Back 85

Acute Respiratory Distress Syndrome = lung inflammation causing respiratory failure

Front 86

What is the ARDS diagnostic triad?

Back 86

CXR:

- Capillary wedge pressure <18

- X-ray of chest with bilateral infiltrates

- Ratio of PaO2 to FiO2 <200

Front 87

What does the classic chest x-ray look like with ARDS?

Back 87

Bilateral fluffy infiltrates

Front 88

How can you remember the PaO2 to FiO2, or PE, ratio?

Back 88

Think: "PUFF" ratio: PF ratio = PaO2:FiO2 ratio

Front 89

At what concentration does O2 toxicity occur?

Back 89

FiO2 of >60% * 48 hours; thus, try to keep FiO2 below 60% at all times

Front 90

What are the ONLY ventilatory parameters that have been shown to decrease mortality in ARDS patients?

Back 90

Low tidal volumes (≤6 cc/kg) and low plateau pressures <30

Front 91

What are the main causes of CO2 retention in ARDS?

Back 91

- Hypoventilation

- Increased dead space ventilation

- Increased CO2 production (as in hypermetabolic states)

Front 92

Why are carbs minimized in the diet/TPN of patients having difficulty with hypercapnia?

Back 92

Respiratory Quotient (RQ) is the ratio of CO2 production to O2 consumption and is highest for carbohydrates (1.0) and lowest for fats (0.7)

Front 93

Why are indwelling arterial lines for BP monitoring in critically ill patients?

Back 93

Because of the need for frequent measurements, the inaccuracy of frequently repeated cuff measurements, the inaccuracy of cuff measurements in hypotension, and the need for frequent arterial blood sampling / labs

Front 94

Which pressures / values are obtained from a Swan-Ganz catheter?

Back 94

- CVP

- PA pressures

- PCWP

- CO

- PVR

- SVR

- Mixed venous O2 saturation

Front 95

What is the Swan-Ganz waveforms in #1?

Back 95

CVP / R atrium

Front 96

What is the Swan-Ganz waveforms in #2?

Back 96

Right ventricle

Front 97

What is the Swan-Ganz waveforms in #3?

Back 97

Pulmonary artery

Front 98

What is the Swan-Ganz waveforms in #4?

Back 98

Wedge

Front 99

What are the other names for PCWP?

Back 99

Wedge or wedge pressure, pulmonary artery occlusion pressure (PAOP)

Front 100

What is PCWP?

Back 100

- Pulmonary capillary pressure after balloon occlusion of the pulmonary artery, which is equal to left atrial pressure because there are no valves in the pulmonary system

- Left atrial pressure is essentially equal to left ventricular end diastolic pressure (LVEDP): left heart preload, and, thus, intravascular volume status.

Front 101

What is the primary use of the PCWP?

Back 101

As an indirect measure of preload = intravascular volume

Front 102

Has the usage of a Swan-Ganz catheter been shown to decrease mortality in ICU patients?

Back 102

NO

Front 103

What is ventilation?

Back 103

Air through the lungs; monitored by PCO2

Front 104

What is oxygenation?

Back 104

Oxygen delivery to the alveoli; monitored by O2 sats and PO2

Front 105

What can increase ventilation to decrease PCO2?

Back 105

Increased respiratory rate (RR), increased tidal volume (minute ventilation)

Front 106

What is minute ventilation?

Back 106

Volume of gas ventilated through the lungs (RR 􏰇 tidal volume)

Front 107

What is tidal volume?

Back 107

Volume delivered with each breath; should be 6 to 8 cc/kg on the ventilator

Front 108

Are ventilation and oxygenation related?

Back 108

Basically no; you can have an O2 sat of 100% and a PCO2 of 150; O2 sats do not tell you anything about the PCO2 (key point!)

Front 109

What can increase PO2 (oxygenation) in the ventilated patient?

Back 109

- Increased FiO2

- Increased PEEP

Front 110

What can decrease PCO2 in the ventilated patient?

Back 110

- Increased RR

- Increased tidal volume (ie, increase minute ventilation)

Front 111

What is the IMV mode of mechanical ventilation?

Back 111

Intermittent Mandatory Ventilation: mode with intermittent mandatory ventilations at a predetermined rate; patients can also breathe on their own above the mandatory rate without help from the ventilator

Front 112

What is the SIMV mode of mechanical ventilation?

Back 112

Synchronous IMV: mode of IMV that delivers the mandatory breath synchronously with patient’s initiated effort; if no breath is initiated, the ventilator delivers the predetermined mandatory breath

Front 113

What is the A-C mode of mechanical ventilation?

Back 113

- Assist-Control ventilation: mode in which the ventilator delivers a breath when the patient initiates a breath, or the ventilator “assists” the patient to breathe; if the patient does not initiate a breath, the ventilator takes “control” and delivers a breath at a predetermined rate

- In contrast to IMV, all breaths are by the ventilator

Front 114

What is the CPAP mode of mechanical ventilation?

Back 114

Continuous Positive Airway Pressure: positive pressure delivered continuously (during expiration and inspira- tion) by ventilator, but no volume breaths (patient breathes on own)

Front 115

What is the pressure support mode ofmechanical ventilation?

Back 115

Pressure is delivered only with an initiated breath; pressure support decreases the work of breathing by overcoming the resistance in the ventilator circuit

Front 116

What is the APRV mode of mechanical ventilation?

Back 116

Airway Pressure Release Ventilation: high airway pressure intermittently released to a low airway pressure (shorter period of time)

Front 117

What is the HFV mode of mechanical ventilation?

Back 117

High Frequency Ventilation: rapid rates of ventilation with small tidal volumes

Front 118

What are the effects of positive pressure ventilation in a patient with hypovolemia or low lung compliance?

Back 118

Venous return and cardiac output are decreased

Front 119

Define PEEP?

Back 119

Positive End Expiration Pressure: positive pressure maintained at the end of a breath; keeps alveoli open

Front 120

What is "physiologic PEEP"?

Back 120

PEEP of 5 cm H2O; thought to approximate normal pressure in normal nonintubated people caused by the closed glottis

Front 121

What are the side effects of increasing levels of PEEP?

Back 121

Barotrauma (injury to airway 􏰃 pneumothorax), decreased CO from decreased preload

Front 122

What is the typical initial ventilator mode setting?

Back 122

Intermittent mandatory ventilation

Front 123

What is the typical initial ventilator tidal volume setting?

Back 123

6-8 ml/kg

Front 124

What is the typical initial ventilator rate setting?

Back 124

10 breaths / min

Front 125

What is the typical initial ventilator FiO2 setting?

Back 125

100% and wean down

Front 126

What is the typical initial ventilator PEEP setting?

Back 126

- 5 cm H2O

- From these parameters, change according to blood-gas analysis

Front 127

What is a normal I:E (inspiratory to expiratory time)?

Back 127

1:2

Front 128

When would you use an inverse I:E ratio (eg, 2:1, 3:1, etc)?

Back 128

To allow for longer inspiration in patients with poor compliance, to allow for "alveolar recruitment"

Front 129

When would you use a prolonged I:E ratio (eg, 1:4)?

Back 129

COPD, to allow time for complete exhalation (prevents "breath stacking")

Front 130

What clinical situations cause increased airway resistance?

Back 130

Airway or endotracheal tube obstruction, bronchospasm, ARDS, mucus plugging, CHF (pulmonary edema)

Front 131

What are the presumed advantages of PEEP?

Back 131

Prevention of alveolar collapse and atelectasis, improved gas exchange, increased pulmonary compliance, decreased shunt fraction

Front 132

What are the possible disadvantages of PEEP?

Back 132

Decreased cardiac output, especially in the setting of hypovolemia; decreased gas exchange; T compliance with high levels of PEEP, fluid retention, increased intracranial pressure, barotrauma

Front 133

What parameters must be evaluated in deciding if a patient is ready to be extubated?

Back 133

Patient alert and able to protect airway, gas .exchange (PaO2 >70, PaCO2 <50), tidal volume (5 cc/kg), minute ventilation (<10 L/min), negative inspiratory pressure (<-20 cm H2O, or more negative), FiO2 ≤40%, PEEP 5, PH >7.25, RR <35, Tobin index <105

Front 134

What is the Rapid-Shallow Breathing (aka Tobin) index?

Back 134

Rate: Tidal volume ratio

Tobin index <105 is associated with successful extubation (Think: Respiratory Therapist = RT = Rate: Tidal volume)

Front 135

What is a possible source of fever in a patient with an NG or nasal endotracheal tube?

Back 135

Sinusitis (diagnosed by sinus films / CT)

Front 136

What is the 35-45 rule of blood gas values?

Back 136

Normal values:

- pH = 7.35 - 7.45

- PCO2 = 35 - 45

Front 137

What meds can be delivered via an endotracheal tube?

Back 137

"NAVEL"

- Narcan

- Atropine

- Vasopressin

- Epinephrine

- Lidocaine

Front 138

What conditions should you think of with increased peak airway pressure and decreased urine output?

Back 138

1. Tension pneumothorax

2. Abdominal compartment syndrome