A 57-year-old man who weighs 150 kg and is 170 cm (67 in) tall is scheduled for cholecystectomy. He has a 100 pack-year smoking history. Which of the following findings on pulmonary function testing are most likely?
You are called to a witnessed cardiac arrest where cardiopulmonary resuscitation is being performed. After successful intubation, arterial blood gas values are PaO2 86 mmHg, PaCO2 63 mmHg, and pH 7.25 at an FiO2 of 1.0. The most appropriate management at this time is to
(A) repeat arterial blood gas analysis using a new specimen
(B) administer sodium bicarbonate
(C) administer fluid challenge with 500 ml of normal saline solution
Following pneumonectomy, a paralyzed patient being mechanically ventilated has the following arterial blood gas values: PaO2 71 mmHg, PaCO2 55 mmHg, pH 7.29. SvO2 is 45%. The most likely explanation for this SvO2 is
A 55-year-old woman who is scheduled to undergo carotid endarterectomy has a history of essential hypertension and chronic obstructive pulmonary disease. Over a 30-minute period beginning one hour after induction of general anesthesia, Sp02 decreases from 99% to 95%. During that time, she has received fentanyl 100 mcg, isoflurane 1%, nitrous oxide 49.5%, oxygen 49.5%, and a nitroglycerin infusion to maintain blood pressure at approximately 160/95 mmHg. Which of the following is the most likely cause for the decline in oxygen saturation?
(A) Decreased cardiac output
(B) Increased dead space ventilation
(C) Inhibition of hypoxic pulmonary vasoconstriction
A 50-year-old woman develops stridor 10 hours after undergoing thyroidectomy. The most appropriate management is administration of which of the following drugs?
Two days after total abdominal hysterectomy, a 54-year-old woman develops lethargy followed by seizures and coma. Laboratory studies show a serum sodium concentration of 108 mEq/L and serum osmolality of 225 mOsm/kg. The most appropriate next step in management is administration of which of the following?
Two days after myocardial infarction involving the left anterior descending coronary artery, a patient's blood pressure decreases acutely from 125/80 to 70/40 mmHg, heart rate increases from 75 to 90 bpm, pulmonary artery pressure increases to 50/30 mmHg, and urine output decreases from 60 to 10 ml/hr. Thermodilution cardiac output has increased from 4 to 7 L/min. The most appropriate action is to
(A) compare mixed venous oxygen saturation in the right atrium and pulmonary artery
(B) draw blood for culture and start antibiotic therapy
(C) start dopamine infusion in low dose
(D) administer a fluid challenge
(E) monitor peripheral capillary oxygenation by transcutaneous oximetry
A 90-kg, 59-year-old man with chronic obstructive pulmonary disease is undergoing laparotomy. Mechanical ventilation is being carried out with a fresh gas flow of 2 L/min at a rate of 16/min and tidal volume of 900 ml; I:E ratio is 1:2.5. PaCO2 remains greater than 50 mmHg. Preoperative PaCO2, was normal. Which of the following is the most appropriate next step?
(A) Adding 10 cmH20 of positive end-expiratory pressure
A 35-kg child requires mechanical ventilation with 100% oxygen at a tidal volume of 350 mL and a rate of 20/min during a severe asthma attack. The most likely cause of severe hypotension after initiating mechanical ventilation is
An acutely ill 65-year-old man with sepsis has severe hypophosphatemia. Which of the following is most likely to result from this electrolyte disorder?
A 75-kg, 45-year-old patient with quadriplegia at the level of C6 is scheduled for elective cholecystectomy. Pulmonary function tests show an FVC of 2.4 L and an FEV, of 1.2 L. Which of the following is the most appropriate conclusion based on these findings?
(A) Intercostal muscle function is normal
(B) SpO, will be 80% or less while breathing room air
(C) Total lung capacity is normal
(D) The patient has chronic obstructive pulmonary disease
A 14-year-old girl with status asthmaticus is receiving oxygen 3 L/min through nasal prongs. Heart rate is 110 bpm. Arterial blood gas values are PaO2 90 mmHg, PaCO2 32 mmHg, and pH 7.46. If ventilation appears unchanged, which of the following is the most reliable sign of impending respiratory failure?
A woman with chronic obstructive pulmonary disease is extubated and minimally responsive after isoflurane anesthesia. She is receiving oxygen 6 L/min through a face mask. Respirations are 10/min, PaO2 is 68 mmHg, PaCO2 is 54 mmHg, and pH is 7.28. The most likely cause of the respiratory acidemia is
(A) blunted sensitivity to low pH in the medullary respiratory center
(B) chronic carbon dioxide retention
(C) decreased lung volume from supine positioning
(D) depression of carotid body chemoreceptors by halothane
(E) suppression of hypoxic ventilatory drive by supplemental oxygen
A child has tachypnea immediately after reintubation for intractable laryngospasm. Oxygen saturation is 78% at an FiO2 of 1.0. A radiograph of the chest taken 15 minutes later is most likely to show
(A) bilateral pleural effusions
(B) diffuse homogenous pulmonary infiltrates
(C) patchy central infiltrates of the right upper lobe
A 70-kg, 77-year-old man Is undergoing left nephrectomy with nitrous oxide, oxygen, fentanyl, and midazolam anesthesia. He has a 90 pack-year history of cigarette smoking and has chronic obstructive pulmonary disease. One hour after incision, expiratory wheezing occurs and peak Inspiratory pressure increases from 35 to 65 cmH20; end-tidal PCO2 is unchanged, but SpO2 decreases from 97% to 88%. The most likely cause is
Following a right lower lobectomy, a patient develops a bronchopleural fistula and becomes hypoxic. He is orally intubated and mechanically ventilated with pure oxygen. PaO2 is 65 mmHg, PaCO2 is 70 mmHg, and pH is 7.25. Which of the following will produce the most favorable change in the blood gases?
A patient is undergoing thoracotomy in the lateral position. Five minutes after initiation of one-lung ventilation using a double-lumen tube and 100% oxygen, SpO2 decreases from 100% to 65%. Which of the following is the most appropriate initial step in management?
(A) Adding continuous positive airway pressure to the nondependent lung
(B) Adding positive end-expiratory pressure to the dependent lung
(C) Increasing the tidal volume to the dependent lung
(D) Resuming two-lung ventilation
(E) Verifying the position of the double-lumen tube
A 120-kg 56-year-old man undergoing gastrectomy during anesthesia with fentanyl and isoflurane has a PetCO2 of 35 mmHg and a PaCO2 of 50 mmHg. His FEV,/FVC ratio is 80% of predicted. Heart rate is 120 bpm and arterial blood pressure is 80/40 mmHg. Which of the following is the most likely cause of the difference in PaCO2 and PetCO2?
A 56-year-old woman with pulmonary fibrosis is scheduled for pneumonectomy. Which of the following parameters best predicts potential postoperative functional impairment?
In a patient with adult respiratory distress syndrome who is being mechanically ventilated, which of the following findings indicates the most severe disease?
During induction of general anesthesia in a patient with a supraglottic tumor, both intubation and subsequent ventilation via a face mask are impossible. A cricothyroidotomy is performed with a 16-gauge intravenous catheter. Which of the following statements is true?
(A) Application of pressures greater than 35 cmH2O to the catheter will increase the risk for pulmonary barotrauma
(B) PaC02 can be maintained at a normal level using a standard circle system attached to the catheter
(C) PaO2 greater than 100 mmHg can be maintained indefinitely using transtracheal jet ventilation with pure oxygen through the catheter
(D) Emergency surgical tracheostomy would have improved the likelihood of survival
(E) The presence of this tumor contraindicates jet ventilation via cricothyroidotomy
If a patient with chronic obstructive pulmonary disease is uncooperative during pulmonary function testing, the most accurate assessment of his disease will be derived from the
In a 65-year-old man, which of the following findings on preoperative pulmonary function testing is associated with the highest risk for respiratory insufficiency following pneumonectomy?
(A) Maximum voluntary ventilation at 65% of predicted
(B) Mean pulmonary artery pressure of 28 mmHg
(C) Predicted postoperative forced expiratory volume in one second (FEV1) of 800 ml
(D) Residual volume to total lung capacity (RV/TLC) ratio of 0.35
A 29-year-old man who has been nasotracheally intubated for two weeks following a motor vehicle accident has a fever (39C) and a constant headache. Leukocyte count is 18,000/mm3. The most likely cause is
Peak airway pressure increases from 25 to 50 cmH2O when beginning right endobronchial ventilation with a right double-lumen tube. The most likely explanation for this increase is
(A) failure to decrease tidal volume
(B) inadvertent intubation of the left mainstem bronchus
(C) intrinsic resistance of small endobronchial lumina
(D) obstruction of the orifice of the right upper lobe
An 8-year-old child with chronic renal failure is scheduled for an operation to create an arteriovenous fistula. Laboratory studies include: Hemoglobin 6.5 g/dl, Blood gases (breathing air) : PaO2 97 mmHg, PaCO2 29 mmHg, pH 7.30 Sodium 129 mEq/L Potassium 5.5 mEq/L Chloride 101 mEq/L Bicarbonate 15 mEq/L. Before inducing general anesthesia, which of the following abnormalities should be corrected?
(A) Anemia
(B) Metabolic acidosis
(C) Potassium concentration
(D) Anemia, metabolic acidosis, and potassium concentration
Five minutes after initiating one-lung ventilation using a double-lumen endobronchial tube, a 70-year-old patient has a decrease in Sp02 from 99% to 90%. Tidal volume and respiratory rate are unchanged. Fiberoptic bronchoscopy verifies appropriate positioning of the tube. Which of the following is the most likely cause of the desaturation?
(A) Blood flow to the nondependent lung
(B) Failure of hypoxic pulmonary vasoconstriction in the dependent lung
(C) Inadequate filling of the bronchial cuff
(D) Inadequate minute ventilation
(E) Surgical manipulation of the nondependent lung
A 35-year-old woman with severe myasthenia gravis is scheduled for thymectomy. Which of the following preoperative pulmonary function tests is most likely to be normal?
During right upper lobectomy and one-lung ventilation with a double-lumen endotracheal tube, the PaO2 decreases to 40 mmHg. The PaCO2 is 39 mmHg. Which of the following is most appropriate?
(A) Confirm position of the tube with bronchoscopy
(B) Apply 5 cmH20 continuous positive airway pressure to the nondependent lung
(C) Apply 5 cmH20 positive end-expiratory pressure to the dependent lung
(D) Resume two-lung ventilation
(E) Clamp the pulmonary artery of the nondependent lung
Prior to occlusion of any major pulmonary blood vessels during a thoracotomy, applying positive end-expiratory pressure to ventilation through the dependent lumen of a double-lumen tube and occluding the upper lumen of the tube will
(A) increase blood flow to the dependent lung
(B) increase the alveolar-arterial oxygen tension difference
A patient is scheduled for right pneumonectomy. A left-sided double-lumen endobronchial tube is inserted. After the endobronchial side is clamped and both cuffs are inflated, breath sounds are heard only on the left. Which of the following is the most likely cause?
(A) Herniation of the endobronchial cuff over the carina
(B) Occlusion of the right upper lobe bronchus
(C) Placement of the endobronchial lumen in the left mainstem bronchus
(D) Placement of the endobronchial lumen in the right mainstem bronchus
(E) Placement of the endobronchial lumen in the trachea
A 50-year-old man who takes aspirin and nifedipine is scheduled for thoracotomy with one-lung ventilation. Which of the following is associated with the greatest risk for intraoperative hypoxemia?
(A) Preoperative withdrawal of nifedipine therapy
(B) Intraoperative mild respiratory acidosis
(C) Intraoperative administration of isoflurane
(D) Intraoperative administration of nitroglycerin
A 60-kg, 17-year-old girl with severe idiopathic scoliosis is scheduled for Harrington rod fixation. Which of the following respiratory parameters is compatible with this disorder?
(A) Alveolar-to-arterial oxygen tension difference (A-aDO2) less than 100 mmHg while breathing pure oxygen
After the bronchial and tracheal cuffs of a right endobronchial tube are inflated, ventilation through the tracheal lumen is not possible. This finding is most consistent with
(A) cuff occlusion of the right upper lobe bronchus
Which of the following changes in pulmonary function best explains the more rapid rate of rise of alveolar concentration of volatile anesthetics in pregnant women than in nonpregnant women?
Compared with a person of normal weight, which of the following findings are most likely on pulmonary function testing of a patient with morbid obesity? (FVC, FEV/FVC, FRC, A-a DO2)?
During craniotomy in the sitting position, end-tidal carbon dioxide tension suddenly decreases. Ventilatory excursion of the chest is normal. Further evaluation is most likely to show a decrease in
A patient undergoes thoracotomy in the lateral decubitus position. Which of the following maneuvers is most likely to increase PaO2 during one-lung ventilation?
(A) Applying continuous positive airway pressure to the nondependent lung
(B) Applying positive end-expiratory pressure to the dependent lung
A 70-kg 22-year-old patient with head trauma and multiple fractures of the long bones is scheduled for fixation of bilateral femoral fractures. Preoperative laboratory studies show a serum sodium concentration of 150 mEq/L, a serum potassium concentration of 3.1 mEq/L, and a urine output greater than 500 ml/hr. Which of the following agents will decrease urine output?
A pulmonary artery catheter is placed in an awake patient breathing room air. Typical right ventricular and pulmonary artery pressure tracings are obtained. With the catheter balloon inflated, blood drawn from the distal port has a PaO2 of 100 mmHg, while a simultaneous radial artery sample has a PaO2 of 90 mmHg. These data indicate that the
A 20-kg, 5-year-old boy under treatment for five days for a cerebral contusion not requiring an operation is still unconscious. After three days of mechanical ventilation, humidified oxygen 40% via T-tube is started. Arterial blood gas analysis shows PaO2 120 mmHg, PaCO2 44 mmHg, pH 7.48, and base excess +6. A nasogastric tube is in place and draining to gravity. Daily fluid therapy has been 5% dextrose in 0.5 normal saline solution 500 ml and 5% dextrose in lactated Ringer's solution 500 ml. Serum electrolyte concentrations are sodium 140, potassium 3.2, and chloride 91 mEq/L. Serum osmolality is 300 mOsm/L. Urine output averages 15 ml/hour. Dexamethasone 8 mg/day has been the only drug therapy. This patient most likely requires