Atelectasis develops within hours of surgery, but pneumonia takes days — knowing the timeline tells you which complication you're facing and what to do about it.
Postoperative respiratory complications are the most common serious complications after surgery, driven by anesthesia-induced alveolar collapse, splinting from pain, immobility, and residual sedation. Atelectasis is the earliest and most frequent — it typically presents within the first 24–48 hours with low-grade fever, diminished breath sounds, and crackles. It is the number-one cause of fever in the first 48 hours postop. Pneumonia follows later, usually 3–5 days postop, presenting with productive cough, higher fever, adventitious lung sounds, and consolidation/infiltrates on chest X-ray (atelectasis typically does not show infiltrates). Laryngospasm and bronchospasm are immediate threats, occurring in the PACU or shortly after extubation. Laryngospasm presents with stridor and absent air movement — intervene with jaw thrust, positive-pressure ventilation via BVM, and notify anesthesia for possible succinylcholine if unresolved. Bronchospasm presents with expiratory wheezing — administer prescribed bronchodilators (albuterol), position upright, and provide supplemental oxygen. Pulmonary embolism presents with sudden dyspnea, tachypnea, pleuritic chest pain, and hypoxemia — often around postop day 3–7; prevention includes SCDs, pharmacologic anticoagulation, and early ambulation. Nursing interventions center on prevention and early detection: incentive spirometry (10 sustained breaths per session, every 1–2 hours while awake, goal of at least 1000–1500 mL or as prescribed), early ambulation, positioning in semi-Fowler's or higher, deep-breathing and coughing exercises, and splinting the incision. Monitor oxygen saturation continuously in the early postop period and assess breath sounds every 2–4 hours. Report SpO₂ below 92% or a sudden increase in respiratory rate.
Key Distinctions
Don't confuse atelectasis fever (low-grade, first 48 hours, no infiltrate on X-ray) with pneumonia fever (higher, day 3–5, infiltrates present) — the timeline and imaging are the differentiators. Students often think incentive spirometry treats atelectasis; it primarily prevents it. Laryngospasm (stridor, no air movement) is not bronchospasm (expiratory wheezing, some air movement) — the interventions differ and misidentification delays rescue.
Clinical Pearl
Think "Wind, Water, Walk, Wound, Wonder drug" for postop fever timing — Wind (lungs/atelectasis) comes first at 24–48 hours, making respiratory the first thing you investigate.