Surgical Intensive Care, C65 P476-489 Flashcards
INTENSIVE CARE UNIT (ICU) BASICS
How is an ICU note written?
P476
By systems:
Neurologic (e.g., GCS, MAE, pain
control)
Pulmonary (e.g., vent settings)
CVS (e.g., pressors, Swan numbers)
GI (gastrointestinal)
Heme (CBC)
FEN (e.g., Chem 10, nutrition)
Renal (e.g., urine output, BUN, Cr)
ID (e.g., Tmax, WBC, antibiotics)
Assessment
Plan
(Note: physical exam included in each
section)INTENSIVE CARE UNIT (ICU) BASICS What is the best way to report urine output in the ICU? P477
24 hrs/last shift/last 3 hourly rate =
“urine output has been 2 liters over last
24 hrs, 350 last shift, and 45, 35, 40 cc
over the last 3 hours”
INTENSIVE CARE UNIT (ICU) BASICS
What are the possible causes
of fever in the ICU?
P477
Central line infection
Pneumonia/atelectasis
UTI, urosepsis
Intra-abdominal abscess
Sinusitis
DVT
Thrombophlebitis
Drug fever
Fungal infection, meningitis, wound
infection
EndocarditisINTENSIVE CARE UNIT (ICU) BASICS
What is the most common
bacteria in ICU pneumonia?
P477
Gram-negative rods
INTENSIVE CARE UNIT (ICU) BASICS What is the acronym for the basic ICU care checklist (Dr. Vincent)? P477
“FAST HUG”:
Feeding
Analgesia
Sedation
Thromboembolic prophylaxis
Head-of-bed elevation (pneumonia prevention) Ulcer prevention Glucose control
INTENSIVE CARE UNIT FORMULAS AND TERMS
YOU SHOULD KNOW
What is CO?
P477
Cardiac Output: HR (heart rate) SV
stroke volume
INTENSIVE CARE UNIT FORMULAS AND TERMS
YOU SHOULD KNOW
What is the normal CO?
P477
4–8 L/min
INTENSIVE CARE UNIT FORMULAS AND TERMS
YOU SHOULD KNOW
What factors increase CO?
P477
Increased contractility, heart rate, and
preload; decreased afterload
INTENSIVE CARE UNIT FORMULAS AND TERMS
YOU SHOULD KNOW
What is CI?
P477
Cardiac Index: CO/BSA (body surface
area)
INTENSIVE CARE UNIT FORMULAS AND TERMS
YOU SHOULD KNOW
What is the normal CI?
P478
2.5–3.5 L/min/M2
INTENSIVE CARE UNIT FORMULAS AND TERMS
YOU SHOULD KNOW
What is SV?
P478
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
INTENSIVE CARE UNIT FORMULAS AND TERMS
YOU SHOULD KNOW
What is the normal SV?
P478
60–100 cc
INTENSIVE CARE UNIT FORMULAS AND TERMS
YOU SHOULD KNOW
What is CVP?
P478
Central Venous Pressure: indirect
measurement of intravascular volume status
INTENSIVE CARE UNIT FORMULAS AND TERMS
YOU SHOULD KNOW
What is the normal CVP?
P478
4–11
INTENSIVE CARE UNIT FORMULAS AND TERMS
YOU SHOULD KNOW
What is PCWP?
P478
Pulmonary Capillary Wedge Pressure:
indirectly measures left atrial pressure,
which is an estimate of intravascular
volume (LV filling pressure)
INTENSIVE CARE UNIT FORMULAS AND TERMS
YOU SHOULD KNOW
What is the normal PCWP?
P478
5–15
INTENSIVE CARE UNIT FORMULAS AND TERMS
YOU SHOULD KNOW
What is anion gap?
P478
Na⁻ – (Cl⁻ + HCO⁻(3))
INTENSIVE CARE UNIT FORMULAS AND TERMS YOU SHOULD KNOW What are the normal values for anion gap? P478
10–14
INTENSIVE CARE UNIT FORMULAS AND TERMS YOU SHOULD KNOW Why do you get an increased anion gap? P478
Unmeasured acids are unmeasured
anions in the equation that are part of the
“counterbalance” to the sodium cation
INTENSIVE CARE UNIT FORMULAS AND TERMS YOU SHOULD KNOW What are the causes of increased anion gap acidosis in surgical patients? P478
Think “SALUD”:
Starvation
Alcohol (ethanol/methanol)
Lactic acidosis
Uremia (renal failure)
DKAINTENSIVE CARE UNIT FORMULAS AND TERMS
YOU SHOULD KNOW
Define MODS.
P478
Multiple Organ Dysfunction Syndrome
INTENSIVE CARE UNIT FORMULAS AND TERMS
YOU SHOULD KNOW
What is SVR?
P478
Systemic Vascular Resistance:
MAP – CVP / CO x 80 (remember,
P = F x R, Power FoRward; and
calculating resistance: R = P/F)
INTENSIVE CARE UNIT FORMULAS AND TERMS
YOU SHOULD KNOW
What is SVRI?
P478
Systemic Vascular Resistance Index:
SVR/BSA
INTENSIVE CARE UNIT FORMULAS AND TERMS
YOU SHOULD KNOW
What is the normal SVRI?
P479
1500–2400
INTENSIVE CARE UNIT FORMULAS AND TERMS
YOU SHOULD KNOW
What is MAP?
P479
Mean Arterial Pressure: diastolic blood pressure + 1/3 (systolic–diastolic pressure) (Note: Not the mean between diastolic and systolic blood pressure because diastole lasts longer than systole)
INTENSIVE CARE UNIT FORMULAS AND TERMS
YOU SHOULD KNOW
What is PVR?
P479
Pulmonary Vascular Resistance:
PA(MEAN) – PCWP / CO x 80 (PA is
pulmonary artery pressure and LA is left
atrial or PCWP pressure)
INTENSIVE CARE UNIT FORMULAS AND TERMS
YOU SHOULD KNOW
What is the normal PVR value?
P479
100 ± 50
INTENSIVE CARE UNIT FORMULAS AND TERMS YOU SHOULD KNOW What is the formula for arterial oxygen content? P479
Hemoglobin x O(2) saturation (S(aO(2))) x 1.34
INTENSIVE CARE UNIT FORMULAS AND TERMS YOU SHOULD KNOW What is the basic formula for oxygen delivery? P479
CO x (oxygen content)
INTENSIVE CARE UNIT FORMULAS AND TERMS YOU SHOULD KNOW What is the full formula for oxygen delivery? P479
CO x (1.34 x Hgb S(aO(2)) x 10
INTENSIVE CARE UNIT FORMULAS AND TERMS YOU SHOULD KNOW What factors can increase oxygen delivery? P479
Increased CO by increasing SV, HR, or
both; increased O(2) content by increasing
the hemoglobin content, S(aO(2)), or both
INTENSIVE CARE UNIT FORMULAS AND TERMS YOU SHOULD KNOW What is mixed venous oxygen saturation? P479
S(vO(2)); simply, the O(2) saturation of the
blood in the right ventricle or pulmonary
artery; an indirect measure of peripheral
oxygen supply and demand
INTENSIVE CARE UNIT FORMULAS AND TERMS YOU SHOULD KNOW Which lab values help assess adequate oxygen delivery? P479
S(vO(2)) (low with inadequate delivery), lactic acid (elevated with inadequate delivery), pH (acidosis with inadequate delivery), base deficit
INTENSIVE CARE UNIT FORMULAS AND TERMS
YOU SHOULD KNOW
What is FENa?
P479
Fractional Excretion of Sodium (Na⁺):
(U(Na) x P(cr) / P(Na) x U(cr)) x 100
INTENSIVE CARE UNIT FORMULAS AND TERMS YOU SHOULD KNOW What is the memory aid for calculating FENa? P479
Think: YOU NEED PEE = U (Urine)
N (Na⁺) P (Plasma); U(Na) x P(cr); for
the denominator, switch everything,
P(Na) x U(cr) (cr = creatinine)
INTENSIVE CARE UNIT FORMULAS AND TERMS YOU SHOULD KNOW What is the prerenal FENa value? P480
<1.0; renal failure from decreased renal blood flow (e.g., cardiogenic, hypovolemia, arterial obstruction, etc.)
INTENSIVE CARE UNIT FORMULAS AND TERMS YOU SHOULD KNOW How long does Lasix® effect last? P480
6 hours = LASIX = LAsts SIX hours
INTENSIVE CARE UNIT FORMULAS AND TERMS YOU SHOULD KNOW What is the formula for flow/pressure/resistance? P480
Remember Power FoRward:
Pressure = Flow x Resistance
INTENSIVE CARE UNIT FORMULAS AND TERMS YOU SHOULD KNOW What is the “10 for 0.08 rule” of acid-base? P480
For every increase of P(aCO(2)) by 10 mm Hg,
the pH falls by 0.08
INTENSIVE CARE UNIT FORMULAS AND TERMS YOU SHOULD KNOW What is the “40, 50, 60 for 70, 80, 90 rule” for O(2) sats? P480
P(a)O(2) of 40, 50, 60 corresponds roughly
to an O(2) sat of 70, 80, 90, respectively
INTENSIVE CARE UNIT FORMULAS AND TERMS YOU SHOULD KNOW One liter of O(2) via nasal cannula raises F(iO(2)) by how much? P480
≈3%
INTENSIVE CARE UNIT FORMULAS AND TERMS YOU SHOULD KNOW What is pure respiratory acidosis? P480
Low pH (acidosis), increased P(aCO(2)), normal bicarbonate
INTENSIVE CARE UNIT FORMULAS AND TERMS YOU SHOULD KNOW What is pure respiratory alkalosis? P480
High pH (alkalosis), decreased P(aCO(2)), normal bicarbonate
INTENSIVE CARE UNIT FORMULAS AND TERMS YOU SHOULD KNOW What is pure metabolic acidosis? P480
Low pH, low bicarbonate, normal P(aCO(2))
INTENSIVE CARE UNIT FORMULAS AND TERMS YOU SHOULD KNOW What is pure metabolic alkalosis? P480
High pH, high bicarbonate, normal
P(aCO(2))
INTENSIVE CARE UNIT FORMULAS AND TERMS YOU SHOULD KNOW List how the body compensates for each of the following: Respiratory acidosis P480
Increased bicarbonate
INTENSIVE CARE UNIT FORMULAS AND TERMS YOU SHOULD KNOW List how the body compensates for each of the following: Respiratory alkalosis P480
Decreased bicarbonate
INTENSIVE CARE UNIT FORMULAS AND TERMS YOU SHOULD KNOW List how the body compensates for each of the following: Metabolic acidosis P480
Decreased P(aCO(2))
INTENSIVE CARE UNIT FORMULAS AND TERMS YOU SHOULD KNOW List how the body compensates for each of the following: Metabolic alkalosis P480
Increased P(aCO(2))
INTENSIVE CARE UNIT FORMULAS AND TERMS
YOU SHOULD KNOW
What does MOF stand for?
P480
Multiple Organ Failure
INTENSIVE CARE UNIT FORMULAS AND TERMS
YOU SHOULD KNOW
What does SIRS stand for?
P480
Systemic Inflammatory Response
Syndrome
SICU DRUGS DOPAMINE What is the site of action and effect at the following levels: Low dose (1–3 g/kg/min)? P481
+ + dopa agonist; renal vasodilation
a.k.a. “renal dose dopamine”
SICU DRUGS DOPAMINE What is the site of action and effect at the following levels: Intermediate dose (4–10 g/kg/min)? P481
1,
+ a(1) + + ℬ(1); positive inotropy and some
vasoconstriction
SICU DRUGS DOPAMINE What is the site of action and effect at the following levels: High dose (>10 g/kg/min)? P481
+ + + a(1) agonist; marked afterload
increase from arteriolar vasoconstriction
SICU DRUGS DOPAMINE Has “renal dose” dopamine been shown to decrease renal failure? P481
NO
SICU DRUGS
DOBUTAMINE
What is the site of action?
P481
+ + + ℬ(1) agonist, + + ℬ(2)
SICU DRUGS
DOBUTAMINE
What is the effect?
P481
↑ inotropy; ↑ chronotropy, decrease in
systemic vascular resistance
SICU DRUGS
ISOPROTERENOL
What is the site of action?
P481
+ + + ℬ(1) and, ℬ(2) agonist
SICU DRUGS
ISOPROTERENOL
What is the effect?
P481
↑ inotropy; ↑ chronotropy; ( + vasodilation
of skeletal and mesenteric vascular beds)
SICU DRUGS
EPINEPHRINE (EPI)
What is the site of action?
P481
+ + a(1), a(2), + + + + ℬ(1), and ℬ(2) agonist
SICU DRUGS
EPINEPHRINE (EPI)
What is the effect?
P481
↑ inotropy; ↑ chronotropy
SICU DRUGS EPINEPHRINE (EPI) What is the effect at high doses? P481
Vasoconstriction
SICU DRUGS
NOREPINEPHRINE (NE)
What is the site of action?
P481
+ + + a(1), a(2), + + + ℬ(1), and ℬ(2) agonist
SICU DRUGS
NOREPINEPHRINE (NE)
What is the effect?
P481
↑ inotropy; ↑ chronotropy; increase
in blood pressure
SICU DRUGS NOREPINEPHRINE (NE) What is the effect at high doses? P482
Severe vasoconstriction
SICU DRUGS
VASOPRESSIN
What is the action?
P482
Vasoconstriction (increases MAP, SVR)
SICU DRUGS
VASOPRESSIN
What are the indications?
P482
Hypotension, especially refractory to
other vasopressors (low-dose infusion—
0.01–0.04 units per minute) or as a bolus
during ACLS (40 u)
SICU DRUGS
NITROGLYCERINE (NTG)
What is the site of action?
P482
+ + + venodilation; + arteriolar dilation
SICU DRUGS
NITROGLYCERINE (NTG)
What is the effect?
P482
Increased venous capacitance, decreased
preload, coronary arteriole vasodilation
SICU DRUGS
SODIUM NITROPRUSSIDE (SNP)
What is the site of action?
P482
+ + + venodilation; + + + arteriolar
dilation
SICU DRUGS
SODIUM NITROPRUSSIDE (SNP)
What is the effect?
P482
Decreased preload and afterload
allowing blood pressure titration
SICU DRUGS SODIUM NITROPRUSSIDE (SNP) What is the major toxicity of SNP? P482
Cyanide toxicity
INTENSIVE CARE PHYSIOLOGY
Define the following terms:
Preload
P482
Load on the heart muscle that stretches
it to end-diastolic volume (end-diastolic
pressure) = intravascular volume
INTENSIVE CARE PHYSIOLOGY
Define the following terms:
Afterload
P482
Load or resistance the heart must pump
against = vascular tone = SVR
INTENSIVE CARE PHYSIOLOGY
Define the following terms:
Contractility
P482
Force of heart muscle contraction
INTENSIVE CARE PHYSIOLOGY
Define the following terms:
Compliance
P482
Distensibility of heart by the preload
INTENSIVE CARE PHYSIOLOGY
What is the Frank-Starling
curve?
P482
Cardiac output increases with increasing
preload up to a point
INTENSIVE CARE PHYSIOLOGY What is the clinical significance of the steep slope of the Starling curve relating end-diastolic volume to cardiac output? P483
Demonstrates the importance of preload
in determining cardiac output
INTENSIVE CARE PHYSIOLOGY What factors influence the oxygen content of whole blood? P483
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
INTENSIVE CARE PHYSIOLOGY What factors influence mixed venous oxygen saturation? P483
Oxygen delivery (hemoglobin
concentration, arterial oxygen saturation,
cardiac output) and oxygen extraction
by the peripheral tissues
INTENSIVE CARE PHYSIOLOGY What lab test for tissue ischemia is based on the shift from aerobic to anaerobic metabolism? P483
Serum lactic acid levels
INTENSIVE CARE PHYSIOLOGY
Define the following terms:
Dead space
P483
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
INTENSIVE CARE PHYSIOLOGY
Define the following terms:
Shunt fraction
P483
That fraction of pulmonary venous blood
that does not participate in gas exchange
Think: shunt = blood
INTENSIVE CARE PHYSIOLOGY
What causes increased dead
space?
P483
Overventilation (emphysema, excessive
PEEP) or underperfusion (pulmonary
embolus, low cardiac output, pulmonary
artery vasoconstriction)
INTENSIVE CARE PHYSIOLOGY At high shunt fractions, what is the effect of increasing F(iO(2)) on arterial P(O(2))? P483
At high shunt fractions (50%), changes
in F(iO(2)) have almost no effect on arterial
P(iO(2)) because the blood that does “see” the
O(2) is already at maximal O(2) absorption;
thus, increasing the F(iO(2)) has no effect
(F(iO(2) can be minimized to prevent
oxygen toxicity)
INTENSIVE CARE PHYSIOLOGY
Define ARDS.
P484
Acute Respiratory Distress Syndrome:
lung inflammation causing respiratory
failure
INTENSIVE CARE PHYSIOLOGY
What is the ARDS diagnostic
triad?
P484
“CXR”:
Capillary wedge pressure 18
X-ray of chest with bilateral infiltrates
Ratio of P(aO(2)) to F(iO(2)) < 200
INTENSIVE CARE PHYSIOLOGY
What does the classic chest
x-ray look like with ARDS?
P484
Bilateral fluffy infiltrates
INTENSIVE CARE PHYSIOLOGY
How can you remember the
P(aO(2)) to F(iO(2)), or PF, ratio?
P484
Think: “PUFF” ratio: PF ratio = P(aO(2)):
F(iO(2)) ratio
INTENSIVE CARE PHYSIOLOGY
At what concentration does
O(2) toxicity occur?
P484
F(iO(2)) of >60% x 48 hours; thus, try to keep F(iO(2)) below 60% at all times
INTENSIVE CARE PHYSIOLOGY What are the ONLY ventilatory parameters that have been shown to decrease mortality in ARDS patients? P484
Low tidal volumes ( ≤6 cc/kg) and low
plateau pressures <30
INTENSIVE CARE PHYSIOLOGY
What are the main causes of
carbon dioxide retention?
P484
Hypoventilation, increased dead space
ventilation, and increased carbon dioxide
production (as in hypermetabolic
states)
INTENSIVE CARE PHYSIOLOGY Why are carbohydrates minimized in the diet/TPN of patients having difficulty with hypercapnia? P484
Respiratory Quotient (RQ) is the ratio of
CO(2) production to O(2) consumption and
is highest for carbohydrates (1.0) and
lowest for fats (0.7)
HEMODYNAMIC MONITORING Why are indwelling arterial lines used for blood pressure monitoring in critically ill patients? P484
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
HEMODYNAMIC MONITORING Which pressures/values are obtained from a Swan-Ganz catheter? P484
CVP, PA pressures, PCWP, CO, PVR,
SVR, mixed venous O(2) saturation
HEMODYNAMIC MONITORING
Identify the Swan-Ganz
waveforms:
P485 (picture)
- CVP/right atrium
- Right ventricle
- Pulmonary artery
- Wedge
HEMODYNAMIC MONITORING
What does the abbreviation
PCWP stand for?
P485
Pulmonary Capillary Wedge Pressure
HEMODYNAMIC MONITORING
Give other names for PCWP.
P485
Wedge or wedge pressure, pulmonary
artery occlusion pressure (PAOP)
HEMODYNAMIC MONITORING
What is it?
P485 (picture)
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.
HEMODYNAMIC MONITORING
What is the primary use of
the PCWP?
P486
As an indirect measure of preload
intravascular volume
HEMODYNAMIC MONITORING Has the usage of a Swan- Ganz catheter been shown to decrease mortality in ICU patients? P486
NO
MECHANICAL VENTILATION
Define ventilation.
P486
Air through the lungs; monitored by
P(CO(2))
MECHANICAL VENTILATION
Define oxygenation.
P486
Oxygen delivery to the alveoli; monitored by O(2) sats and P(O(2))
MECHANICAL VENTILATION What can increase ventilation to decrease P(CO(2))? P486
Increased respiratory rate (RR),
increased tidal volume (minute
ventilation)
MECHANICAL VENTILATION
What is minute ventilation?
P486
Volume of gas ventilated through the
lungs (RR x tidal volume)
MECHANICAL VENTILATION
Define tidal volume.
P486
Volume delivered with each breath;
should be 6 to 8 cc/kg on the ventilator
MECHANICAL VENTILATION
Are ventilation and
oxygenation related?
P486
Basically no; you can have an O(2) sat of
100% and a P(CO(2)) of 150; O(2) sats do not tell
you anything about the P(CO(2)) (key point!)
MECHANICAL VENTILATION What can increase P(O(2)) (oxygenation) in the ventilated patient? P486
Increased F(iO(2)) Increased PEEP
MECHANICAL VENTILATION
What can decrease P(CO(2)) in
the ventilated patient?
P486
Increased RR
Increased tidal volume (i.e., increase
minute ventilation)
MECHANICAL VENTILATION
Define the following modes:
IMV
P486
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
MECHANICAL VENTILATION
Define the following modes:
SIMV
P487
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
MECHANICAL VENTILATION
Define the following modes:
A-C
P487
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
MECHANICAL VENTILATION
Define the following modes:
CPAP
P487
Continuous Positive Airway Pressure:
positive pressure delivered continuously
(during expiration and inspiration)
by ventilator, but no volume
breaths (patient breathes on own)MECHANICAL VENTILATION
Define the following modes:
Pressure support
P487
Pressure is delivered only with an
initiated breath; pressure support
decreases the work of breathing by
overcoming the resistance in the
ventilator circuitMECHANICAL VENTILATION
Define the following modes:
APRV
P487
Airway Pressure Release Ventilation:
high airway pressure intermittently
released to a low airway pressure
(shorter period of time)
MECHANICAL VENTILATION
Define the following modes:
HFV
P487
High Frequency Ventilation: rapid rates
of ventilation with small tidal volumes
MECHANICAL VENTILATION What are the effects of positive pressure ventilation in a patient with hypovolemia or low lung compliance? P487
Venous return and cardiac output are
decreased
MECHANICAL VENTILATION
Define PEEP:
P487
Positive End Expiration Pressure:
positive pressure maintained at the end
of a breath; keeps alveoli open
MECHANICAL VENTILATION
What is “physiologic PEEP”?
P488
PEEP of 5 cm H(2)O; thought to
approximate normal pressure in normal
nonintubated people caused by the
closed glottis
MECHANICAL VENTILATION
What are the side effects of
increasing levels of PEEP?
P488
Barotrauma (injury to airway =
pneumothorax), decreased CO from
decreased preload
MECHANICAL VENTILATION What are the typical initial ventilator settings: Mode? P488
Intermittent mandatory ventilation
MECHANICAL VENTILATION What are the typical initial ventilator settings: Tidal volume? P488
6–8 ml/kg
MECHANICAL VENTILATION What are the typical initial ventilator settings: Ventilator rate? P488
10 breaths/min
MECHANICAL VENTILATION What are the typical initial ventilator settings: F(iO(2))? P488
100% and wean down
MECHANICAL VENTILATION What are the typical initial ventilator settings: PEEP? P488
5 cm H(2)O
From these parameters, change
according to blood-gas analysis
MECHANICAL VENTILATION
What is a normal I:E (inspiratory
to expiratory time)?
P488
1:2
MECHANICAL VENTILATION When would you use an inverse I:E ratio (e.g., 2:1, 3:1, etc.)? P488
To allow for longer inspiration in patients
with poor compliance, to allow for
“alveolar recruitment”
MECHANICAL VENTILATION
When would you use a prolonged
I:E ratio (e.g., 1:4)?
P488
COPD, to allow time for complete
exhalation (prevents “breath stacking”)
MECHANICAL VENTILATION What clinical situations cause increased airway resistance? P488
Airway or endotracheal tube obstruction,
bronchospasm, ARDS, mucous plug,
CHF (pulmonary edema)
MECHANICAL VENTILATION
What are the presumed
advantages of PEEP?
P488
Prevention of alveolar collapse and
atelectasis, improved gas exchange,
increased pulmonary compliance,
decreased shunt fraction
MECHANICAL VENTILATION
What are the possible
disadvantages of PEEP?
P488
Decreased cardiac output, especially in the setting of hypovolemia; decreased gas exchange; ↓ compliance with high levels of PEEP, fluid retention, increased intracranial pressure, barotrauma
MECHANICAL VENTILATION What parameters must be evaluated in deciding if a patient is ready to be extubated? P489
Patient alert and able to protect airway,
gas exchange (P(aO(2)) >70, (P(aO(2)) 5 cc/kg), minute
ventilation ( < –20 cm H(2)O,
or more negative), F(iO(2)) ≤40%, PEEP 5,
PH >7.25, RR <105
MECHANICAL VENTILATION What is the Rapid-Shallow Breathing (a.k.a. Tobin) index? P489
Rate: Tidal volume ratio; Tobin index
105 is associated with successful
extubation (Think: Respiratory Therapist
= RT = Rate: Tidal volume)
MECHANICAL VENTILATION What is a possible source of fever in a patient with an NG or nasal endotracheal tube? P489
Sinusitis (diagnosed by sinus films/CT)
MECHANICAL VENTILATION
What is the 3545 rule of
blood gas values?
P489
Normal values:
pH = 7.357.45
P(CO(2)) = 3545
MECHANICAL VENTILATION Which medications can be delivered via an endotracheal tube? P489
Think “NAVEL”:
Narcan
Atropine
Vasopressin
Epinephrine
LidocaineMECHANICAL VENTILATION What conditions should you think of with c peak airway pressure and T urine output? P489
- Tension pneumothorax
2. Abdominal compartment syndrome
