Tony Montana, an international businessman, was rushed to the hospital due to vomiting and a decreased level of consciousness.

The patient displays slow and deep (Kussmaul breathing), and he is lethargic and irritable in response to stimulation.

He appears to be dehydrated—his eyes are sunken and mucous membranes are dry—and he has a two-week history of polydipsia, polyuria, and weight loss.

Measurement of arterial blood gas shows pH 7.0, PaC02 23 mm Hg, and HCO3 12 mmol/L; other results are Na+ 126 mmol/L, K+ 5 mmol/L, and C- 95 mmol/L. What is your assessment?

Choice A rationale

Respiratory acidosis is characterized by a low pH and an elevated PaCO2. The patient's pH is elevated (7.61), indicating alkalosis, and the PaCO2 is low (22 mmHg). These findings are the opposite of what would be seen in respiratory acidosis.

Choice B rationale

The pH of 7.61 is significantly elevated, indicating alkalosis. The PaCO2 of 22 mmHg is markedly decreased below the normal range (35-45 mmHg). This decrease in carbon dioxide, a potent acid, directly causes the alkalosis. The bicarbonate (HCO3) level of 25 mEq/L is within the normal range (22-26 mEq/L), indicating that the renal system has not yet initiated any compensatory response. Therefore, this pattern is consistent with uncompensated respiratory alkalosis, primarily driven by hyperventilation.

Choice C rationale

Metabolic alkalosis would present with an elevated pH and an elevated bicarbonate level. While the pH is elevated, the bicarbonate (25 mEq/L) is within the normal range, and the PaCO2 is low, which is inconsistent with metabolic alkalosis as the primary imbalance.

Choice D rationale

Metabolic acidosis is characterized by a low pH and a low bicarbonate level. The patient's pH is high (alkalotic) and the bicarbonate is normal. This contradicts the diagnostic criteria for metabolic acidosis.

Choice A rationale

Suctioning should be performed only when clinically indicated, such as in the presence of visible secretions, adventitious breath sounds, or a decline in oxygen saturation. Routine, unnecessary suctioning can cause mucosal trauma, hypoxemia, and increased risk of infection. This "as needed" approach minimizes potential complications and preserves airway integrity.

Choice B rationale

Hyperoxygenating the patient with 100% oxygen for 30-60 seconds prior to suctioning helps to create an oxygen reserve in the lungs and minimize the risk of hypoxemia during the procedure. Suctioning can transiently reduce lung volumes and gas exchange, and pre-oxygenation mitigates this by saturating hemoglobin and dissolved plasma oxygen.

Choice C rationale

Suctioning for longer than 10-15 seconds on each pass significantly increases the risk of hypoxemia, atelectasis, and vagal stimulation leading to bradycardia. Prolonged suctioning depletes oxygen from the airways and can cause physiological distress. Brief passes allow for reoxygenation between attempts and minimize adverse events.

Choice D rationale

Performing hand hygiene prior to suctioning is a critical infection control measure. This practice reduces the transmission of microorganisms from the healthcare provider's hands to the patient's airway, thereby preventing healthcare-associated infections like ventilator-associated pneumonia. Adherence to strict aseptic technique is paramount in airway management.

Choice E rationale

Suctioning should never be performed while inserting the catheter into the artificial airway. Applying negative pressure during insertion can cause significant mucosal trauma, bleeding, and increased risk of infection by pulling tissue into the catheter lumen. Suction should only be applied intermittently and during withdrawal of the catheter, to remove secretions effectively and safely.