Which diagnostic tests should be performed to evaluate a hypertensive, obese adult five days after ocular surgery who presents with new‑onset cough and dyspnea?

Diagnostic Evaluation for Post-Operative Dyspnea and Cough

In a hypertensive, obese adult presenting five days after ocular surgery with new-onset cough and dyspnea, the immediate diagnostic priority is to obtain a chest X-ray, 12-lead ECG, pulse oximetry, and basic laboratory tests (complete blood count, basic metabolic panel, and cardiac biomarkers) to differentiate between cardiac decompensation, pulmonary embolism, and postoperative pneumonia. 1

Initial Bedside Assessment and Vital Signs Monitoring

• Blood pressure measurement is critical in this postoperative hypertensive patient, with trigger values for assessment being systolic pressure <100 mm Hg (or <75% of baseline) or >160 mm Hg (or >140% of baseline). 1

• Pulse oximetry should be obtained immediately, as oxygen saturation <92% on room air warrants arterial blood gas analysis to assess for hypoxemia and hypercapnia. 1

• Increased frequency of vital signs monitoring (every 2 hours rather than every 4-6 hours) is recommended for postoperative patients showing respiratory symptoms or blood pressure trends. 1

Cardiac Evaluation

Echocardiography is the single most important diagnostic test when dyspnea of suspected cardiac origin presents in an obese, hypertensive patient, as it non-invasively evaluates left ventricular systolic and diastolic function, valvular disease, and pulmonary hypertension. 2

• The combination of obesity, hypertension, and new dyspnea strongly suggests cardiac etiology, particularly heart failure with preserved ejection fraction or flash pulmonary edema. 1, 2

• A 12-lead ECG must be obtained to detect left ventricular hypertrophy (common in chronic hypertension), arrhythmias, or acute ischemic changes. 1, 3

• Cardiac biomarkers (troponin, BNP or NT-proBNP) should be measured, as elevated levels would support cardiac decompensation or acute coronary syndrome. 1

Pulmonary Assessment

• Chest X-ray (posteroanterior and lateral) is mandatory in all severely obese postoperative patients to evaluate for pneumonia, pulmonary edema, pleural effusion, or cardiac chamber enlargement. 1

• Arterial blood gas analysis is indicated when oxygen saturation is <92% or when hypoventilation/hypercapnia is suspected in obese patients with obesity-hypoventilation syndrome. 1

• While CT pulmonary angiography would be the definitive test for pulmonary embolism, it should be reserved for cases where clinical probability is moderate-to-high based on Wells score or when initial tests are inconclusive. 1

Laboratory Evaluation

• Complete blood count helps identify infection (elevated white blood cell count suggesting pneumonia) or anemia. 1, 4

• Basic metabolic panel (electrolytes, creatinine, glucose) is essential because hypokalemia may indicate undiagnosed primary aldosteronism contributing to resistant hypertension, and renal function affects management decisions. 3, 5

• C-reactive protein, procalcitonin, and lactate dehydrogenase are useful when infection or inflammatory processes are suspected, with significantly elevated values suggesting severe disease. 4

Structured Bedside Assessment for Postoperative Hypotension or Hypertension

If blood pressure is abnormal, a focused history and physical examination should characterize the hemodynamic state as stable versus unstable: 1

• Assess for end-organ dysfunction: altered mental status (encephalopathy), chest pain (myocardial ischemia), dyspnea with crackles (pulmonary edema), or oliguria (renal hypoperfusion). 1

• Passive leg raise test can predict fluid responsiveness in hypotensive patients (positive likelihood ratio = 11, specificity 92%), avoiding unnecessary fluid administration in ~50% of postoperative hypotensive patients who require vasopressor or inotropic support instead. 1

Risk Stratification in Obese Surgical Patients

• Obesity increases perioperative cardiovascular risk, with cardiac arrest rates of 1.6% and annualized mortality of 1.5% following bariatric procedures—substantially higher than general surgery. 1

• Obstructive sleep apnea (present in 25-50% of obese hypertensive patients) increases risk of postoperative respiratory complications and should be suspected if the patient has snoring, witnessed apneas, or daytime sleepiness. 1, 5

• Obesity-hypoventilation syndrome may present with hypercapnia and should be evaluated with arterial blood gases if suspected. 1

Common Pitfalls to Avoid

• Do not attribute dyspnea solely to deconditioning in obese patients without excluding cardiac and pulmonary pathology, as physical examination often underestimates cardiac dysfunction in obesity (distant heart sounds, baseline pedal edema). 1

• Do not delay echocardiography waiting for other test results when cardiac etiology is suspected, as it provides immediate diagnostic information that guides management. 2

• Do not perform high-flow oxygen (>6 L/min) if infection is suspected, as this generates aerosols and increases transmission risk; use low-flow systems with air-entrainment devices instead. 1

• Avoid assuming postoperative hypertension is benign—systolic pressure >160 mm Hg requires clinical assessment even without symptoms, as it may herald impending complications. 1

Algorithm for Test Selection

1. Immediate bedside: Vital signs (BP, HR, RR, O₂ saturation), focused cardiovascular and pulmonary examination
2. First-line tests (obtain simultaneously): Chest X-ray, 12-lead ECG, pulse oximetry, arterial blood gas (if O₂ sat <92%)
3. Laboratory panel: CBC, basic metabolic panel, cardiac biomarkers (troponin, BNP)
4. Echocardiography: Perform urgently if cardiac etiology suspected based on clinical presentation or abnormal ECG/biomarkers
5. CT pulmonary angiography: Reserve for moderate-to-high probability of pulmonary embolism after initial evaluation

This stepwise approach prioritizes life-threatening conditions (acute heart failure, pulmonary embolism, severe pneumonia) while avoiding unnecessary testing in a postoperative patient. 1, 2