Intraoperative Pulmonary Embolism: Risk Factors Raise Suspicion while Physiology Drives Escalation

Background : Pulmonary embolism (PE) is an uncommon but potentially catastrophic perioperative complication associated with significant morbidity, mortality, and healthcare utilization. Diagnosis under general anesthesia is uniquely challenging because traditional symptoms including dyspnea, pleuritic chest pain, and respiratory distress are absent. Consequently, clinicians must rely upon physiologic indicators such as changes in end-tidal carbon dioxide (ETCO₂), oxygenation, hemodynamics, arterial blood gas analysis, and echocardiographic findings. Many of these markers possess limited specificity and frequently overlap with more common perioperative abnormalities. Case Presentation : We present a high-risk, postpartum trauma patient undergoing orthopedic fixation of acetabular fracture, who had recently experienced placental abruption, emergent cesarean section, massive obstetric hemorrhage with concomitant disseminated intravascular coagulation requiring massive transfusion of multiple blood products. Intraoperative concern for pulmonary embolism was raised following identification of an elevated alveolar-arterial oxygen gradient despite preserved oxygenation, stable ETCO₂, and hemodynamic stability. Surgical intervention was aborted to obtain computed tomography pulmonary angiography (CTPA). CTPA demonstrated no evidence of clinically significant pulmonary embolism, although small segmental or subsegmental emboli could not be excluded. Discussion : This case highlights the diagnostic uncertainty associated with suspected pulmonary embolism during general anesthesia and illustrates the limitations of isolated physiologic markers when interpreted outside the broader clinical context. We review the strengths and limitations of commonly utilized intraoperative indicators of pulmonary embolism and propose a practical framework for escalation emphasizing physiologic deterioration rather than isolated abnormalities. Conclusion : Risk factors should raise suspicion for pulmonary embolism, whereas escalation decisions should be guided by objective physiologic deterioration, echocardiographic findings, and overall clinical context. A structured approach to intraoperative PE evaluation may improve consistency of decision-making while minimizing unnecessary interruption of surgical care. We propose a signal-based algorithm for evaluation of suspected intraoperative PE (Fig. 1).