A 52-year-old patient with severe acute pancreatitis is in the ICU on hospital day 3. The nurse notes hypoxia (SpO2 88 percent on 6 L NC), bilateral crackles, and a new chest x-ray showing bilateral diffuse infiltrates. There is no jugular venous distention, no peripheral edema, and the heart sounds are normal. Which complication does the nurse most likely identify?

Severe acute pancreatitis releases pancreatic enzymes and a systemic inflammatory cascade that injures the alveolar-capillary membrane and produces non-cardiogenic pulmonary edema — the hallmark of acute respiratory distress syndrome (ARDS). Bilateral diffuse infiltrates, severe hypoxemia, and absence of left atrial hypertension findings (no JVD, no peripheral edema, normal heart sounds) point away from cardiogenic edema and toward ARDS. ARDS is classified by the Berlin definition with PaO2/FiO2 thresholds and is one of the most lethal complications of severe pancreatitis. Choice 1 is wrong because cardiogenic edema would show JVD, peripheral edema, S3, and elevated BNP. Choice 2 is wrong because pseudocyst forms over weeks, not days. Choice 4 is unlikely without focal infiltrates, fever, or purulent secretions and is not the dominant explanation for the cluster.

Severe acute pancreatitis ranks among the most systemically dangerous abdominal diseases. Activated pancreatic enzymes and a release of pro-inflammatory cytokines (IL-6, TNF-alpha) damage the alveolar-capillary membrane and produce non-cardiogenic pulmonary edema — acute respiratory distress syndrome (ARDS) by Berlin criteria. Other complications cluster around the same systemic mechanism: pancreatic necrosis, acute kidney injury, hypocalcemia from saponification of fat, hyperglycemia from beta-cell injury, disseminated intravascular coagulation, and shock. Severity scoring uses Ranson criteria (5 at admission, 6 at 48 hours), the BISAP score, or APACHE II. Management priorities are aggressive isotonic fluid resuscitation early, NPO with judicious enteral feeding once tolerated rather than routine TPN, opioid analgesia, electrolyte and glucose management, ICU monitoring for organ failure, and antibiotics only for documented infected necrosis. Imaging is usually contrast-enhanced CT after the first 72 hours to assess necrosis. Distinguishing ARDS from cardiogenic edema, hospital-acquired pneumonia, and pseudocyst-related effusion drives the right interventions.