ICU Flashcards
Interventions which have been shown to reduce the duration of mechanical ventilation in patients with respiratory failure include which one of the following
Routine daily discontinuation of sedative infusions
Successful use of non-invasive ventilation to prevent intubation will be most likely in a patient with which of the following
COPD with severe hypercarbia
As ICU director, you are asked to help design a protocol to reduce the excessive rate of catheter-related bloodstream infections. Which of the following is supported by randomized trials showing reduction in the rate of these infections
Sterile gown, cap, mask, gloves, and full drapes during insertion
All of the following findings are commonly present in a patient with cardiogenic shock from acute myocardial infarction EXCEPT
Bradycardia
Shock from any cause reduces coronary perfusion pressure, and associated pulmonary edema causes hypoxemia. Other physiologic compensatory responses to acute, severe pump failure include renal fluid retention and vasoconstriction. Although complete heart block might complicate a massive MI, the typical response to low output cardiogenic shock is tachycardia.
Which of the following findings would be more typical of intrinsic renal injury than of pre-renal azotemia:
Fractional excretion of urea > 35%
Pre-renal azotemia from low cardiac output or hypovolemia causes the kidney to intensely retain sodium and water. Urine becomes hyperosmolar, with low fractional excretion of sodium and urea. BUN rises excessively compared to the increase in creatinine. A high fractional excretion of urea is more typical of intrinsic renal injury. The FEUrea remains diagnostic even in patients receiving furosemide which can elevate sodium excretion
Which of the following interventions has been demonstrated to prevent or reduce the severity of acute kidney injury in ICU patients:
None of the above
You are caring for an oliguric patient with sepsis from peritonitis. Their mean arterial pressure is 70 mmHg on 3.0 mcg/kg/min of norepinephrine. BUN is 86. pH is 7.15 with serum HCO3 of 12. Sodium is 129 and K is 6.6. The most appropriate mode of renal replacement therapy in this patient is which one of the following:
CVVHD – Continuous venovenous hemodialysis
This patient has several indications for acute dialysis, including hyperkalemia and severe acidosis. Low BP requiring vasopressors is a contraindication to intermittent hemodialysis because it would further lower BP. Peritoneal dialysis has been used in patients in shock but would be contraindicated in peritonitis. Among the continuous renal replacement therapies, hemodialysis would better correct blood chemistry than would hemofiltration
Proper tracheal placement of an endotracheal tube is most definitively supported by which of the following findings
End-tidal exhaled CO2 of 6%
In a patient with an unchanging minute ventilation, a decreased PaCO2 could be caused by which one of the following
Decreased pulmonary dead space
Which of the following is characteristic of the arterial blood gases in severe carbon monoxide poisoning
Normal PaO2
Carbon monoxide binds avidly to hemoglobin and reduces the available sites for oxygen to bind. This reduces the arterial oxygen content, but not the PaO2. The %saturation is calculated from the PaO2. Because arterial content is reduced, after extraction by the tissues, mixed venous oxygen content is reduced as well. Hypercarbia is not seen with carbon monoxide poisoning; lactic acidosis, if present, would stimulate ventilation
The following arterial blood gas is drawn on a mechanically ventilated patient breathing 30% oxygen: pH = 7.44, PaCO2 = 30, PaO2 = 274 mmHg. This is most suggestive of
Laboratory error
A patient being mechanically ventilated on 90% oxygen, 12 cmH2O PEEP and volume Assist/Control ventilation has the following ABGs : pH = 7.43, PaCO2 = 20, PaO2 = 55, HCO3 = 15. This ABG indicates which of the following abnormalities:
Combined metabolic acidosis and respiratory alkalosis
The pH is on the alkalotic side of normal. If this were a simple acute respiratory alkalosis, the pH would be higher. It increases about 0.08 units/10 mmHg fall in PCO2. Compensation for a metabolic acidosis would not increase pH to >7.40; it would remain in the low-normal or sub-normal range. Combined metabolic alkalosis and respiratory acidosis could result in this pH, but the PCO2 has changed in the wrong direction. V/Q mismatch would not account for the pH and PCO2 abnormalities, and PaO2 should be much higher on 90% oxygen.
Assuming they lack contraindications to the medications, all of the following are recommended in the initial treatment of a patient presenting with non-ST segment elevation MI and ongoing chest pain EXCEPT:
ACE-inhibitor
Which of the following therapies would be most useful useful to improve cardiac output in the ICU management of acute decompensated heart failure:
Dobutamine
Which of the following illnesses would most typically cause hypercarbic respiratory failure
Myasthenia Gravis
A patient with a large pulmonary embolism has a blood pressure of 95/70 mmHg, heart rate of 123, and a blood gas on room air of pH 7.30, PaCO2 = 30 mmHg, PaO2 = 40 mmHg. Which of the following therapies should be given first:
Supplemental oxygen
Propranolol would be contraindicated in this situation, as it might precipitate shock in this patient with compensatory tachycardia. NIV would not help since the patient is ventilating just fine. A fluid bolus might help with the tachycardia, but this patient’s blood pressure is not critically low. Heparin and oxygen are both indicated, but oxygen to relieve the severe hypoxemia is the more urgent.
A paralyzed patient is receiving volume assist/control mechanical ventilation. If they develop a fever, which one of the following changes will occur?
PaCO2 will rise
Which of the following disorders is most likely to respond to non-invasive ventilation without requiring intubation?
Asthma exacerbation
A sedated patient is receiving assist/control ventilation through a #6 endotracheal tube placed emergently. To allow bronchoscopy, the tube is exchanged for a larger, #8 tube. Which of the following changes in respiratory mechanics would this cause?
Decreased peak airway pressure
An anxious patient is receiving assist/control ventilation at a set rate of 24. Their measured respiratory rate is 28. An arterial blood gas shows a pH of 7.55, PaCO2 22, PaO2 133. What effect will decreasing the set rate to 12 have on their arterial blood gases?
No effect
A heavily sedated child on pressure/control ventilation is receiving a tidal volume of 150 ml with a set pressure of 20 cmH20 and PEEP set at 0 cmH2O. They develop bronchospasm and autoPEEP (intrinsic PEEP) increases from zero to 10 cmH2O. If no changes are made to the ventilator, which one of the following changes to their ventilation will occur?
Minute ventilation (Ve) will fall
Pressure-control ventilation limits the airway pressure to the value you have set above the set PEEP. The development of autoPEEP during bronchospasm indicates the lungs do not have enough time to empty fully during expiration. However, because the maximum airway pressure is fixed by the ventilator, end-inspiratory lung volume will not increase. Tidal volume becomes squeezed between the fixed end-inspiratory value and the rising end-expiratory value. Minute ventilation will fall and PaCO2 will rise. Airway resistance will have increased because of the bronchospasm but will not be altered by the ventilatory pattern.
In which of the following modes of ventilation will the patient do the MOST work of breathing?
Continuous positive airway pressure
A patient receiving pressure support ventilation develops peritonitis with a tense abdomen and will need emergency surgery. While awaiting the OR, the best change to make to the ventilator is which one of the following:
Change mode to volume assist control ventilation
You place a pulmonary artery catheter to assist in the differential diagnosis and management of a patient with a blood pressure of 80/60. Match the following patient description with the appropriate hemodynamic profile in the table below:
A 17 year old girl who is intubated for surgical resection of a Meckel’s diverticulum. She is placed on high levels of PEEP in an attempt to prevent atelectasis.
D
High levels of PEEP increase pleural pressure and lung volume, especially in a patient such as this with normal lungs. This will increase pulmonary vascular resistance and elevate all of the intrathoracic vascular pressures. The increased right atrial pressure will decrease venous return. This is the profile shown in D
You place a pulmonary artery catheter to assist in the differential diagnosis and management of a patient with a blood pressure of 80/60. Match the following patient description with the appropriate hemodynamic profile in the table below:
A 68 year old man recovering from an MVA who has a massive pulmonary embolism on hospital day 6.
A
An acute massive pulmonary embolism will increase pulmonary vascular resistance. Pulmonary artery pressure will rise, but mean Ppa will not usually exceed about 40 mmHg because the right ventricle is thin-walled and incapable of generating more pressure. Cardiac output will fall. Left-sided pressures such as the wedge pressure remain relatively normal, but can increase somewhat from the mechanism of ventricular interdependence as the RV dilates. This is described by the set of parameters shown in row A.
In which of the following situations should an anti-pseudomonal agent be included in empiric coverage for a septic patient
55 year old woman with suspected ventilator-associated pneumonia, one week into therapy for ARDS
You begin empiric vancomycin and piperacillin/tazobactam on an intubated Medical patient with a central venous line and fever who has been in the MICU for 5 days. The central line will be removed, and prior to antibiotic administration you sent cultures of urine, blood, and sputum. The earliest that it is correct to discontinue vancomycin is when which one of the following conditions have been met:
72 hours later, when all diagnostic studies and cultures are negative but the fever persists
Antibiotic “stewardship” describes the responsible use of antibiotics to minimize acquisition of resistance. Vancomycin must often be started empirically to cover for MRSA. However, staph grows rapidly and readily and vancomycin can be discontinued after 48 hours if cultures are negative. Positive blood cultures with an alternative organism is strongly suggestive that vancomycin is unnecessary, but co-infection is possible. Continued fever suggests that the antibiotics are ineffective, the fever is not from infection or an abscess has not been drained
Which one of the following antibiotics require dose adjustment for a patient with renal insufficiency and a serum Cr = 2.5 mg%:
vancomycin
In a patient with a definite, severe allergy to penicillin, which antibiotic is least likely to cause an allergic reaction
aztreonam
Although structurally a beta-lactam, aztreonam has the least cross-reactivity to penicillin and can be safely administered to patients with penicillin allergy
Meropenem has activity against all of the following organisms EXCEPT
MRSA
A patient with HIV/AIDS is being treated with Bactrim for PCP pneumonia, is mechanically ventilated on 80% oxygen and 12 cmH2O PEEP, and is being sedated with infusions of fentanyl, lorazepam, and propofol. Mean arterial pressure has been maintained 65-70 mmHg on norepinephrine infusion. They are receiving routine prophylactic therapy for DVT (unfractionated heparin, sc, and oral pantoprazole). They have been slowly improving, until day 7, when their blood gases show a new acidosis (pH 7.25, PaCO2 32, PaO2 69). The nurse noted a heart rate of 45 and sent cardiac enzymes. Creatine kinase is 554 with 1% MB fraction. The medication that should be immediately discontinued because it is the most likely cause of these new findings is:
Propofol
Which of the following statements is correct in regards to the association between ICU delirium and mortality
Delirium during an ICU stay increases the risk of both hospital and 6-month mortality.