A Simple and Safe Method of Ruling Out Pulmonary Embolism in Postoperative Plastic Surgery Patients

Abstract

Sir: Pulmonary embolism is one of the most feared complications of plastic surgery, and as authors have stated, preventive measures are the best way to minimize this potentially fatal complication. However, even with all the possible prophylactic measures, pulmonary embolism may be unavoidable and necessitates prompt diagnosis and aggressive treatment. A plastic surgeon is usually not the one who treats the pulmonary embolism, but he or she should be the one who diagnoses it first to get appropriate help in a timely manner to prevent a deadly outcome. In this communication, we share a simple, noninvasive, bedside algorithm that we have been using in our clinical practice to diagnose pulmonary embolism in postoperative plastic surgery patients. The diagnosis of pulmonary embolism is challenging in the postoperative period. If it is unrecognized or left untreated, it may result in a mortality rate as high as 30 percent in hospitalized patients; this rate can be decreased to 8 percent with early diagnosis and proper treatment.1,2 Thus, it is imperative to establish a bedside diagnostic algorithm to diagnose and treat this deadly complication. Wells et al. established a simplified clinical scoring model,3 which was derived from their original study,4 to eliminate some of the disadvantages of the complex scoring systems. In their simplified model, they gave points to various clinical signs, symptoms, and risk factors, and categorized the patients into two groups: pulmonary embolism unlikely and pulmonary embolism likely (Table 1). This is a relatively simple scoring system that can be applied at the bedside to any patient with suspected pulmonary embolism. This simplified model is particularly helpful when combined with D-dimer blood levels of patients with suspected pulmonary embolism.Table 1: Simplified Clinical Scoring Model for Diagnosis of Pulmonary EmbolismD-dimer is a degradation product of a cross-linked fibrin blood clot. The elevated D-dimer levels are typically seen with acute venous thromboembolism, but it is not a specific test, because elevated levels may also be seen with recent surgery, malignancy, pregnancy, infections, and in the older population. A pulmonary-embolism-unlikely result from the simplified clinical scoring model (Table 1) and a negative D-dimer value can safely exclude the diagnosis of pulmonary embolism without the need for further diagnostic studies with a 2 percent false-negative rate, which is similar to standard pulmonary angiography.5 This approach is particularly helpful in free flap patients, because transport of these patients to nuclear medicine or computed tomography suites is cumbersome, and when both simplified clinical scoring and D-dimer levels are negative, an unnecessary and potentially dangerous trip may be avoided. If pulmonary embolism is likely based on the simplified clinical scoring system and/or the D-dimer level is positive, further diagnostic studies are usually needed to rule in or rule out the diagnosis of pulmonary embolism. The most commonly used diagnostic studies are spiral computed tomography and ventilation-perfusion nuclear scanning. Both studies have advantages and disadvantages, and either one is acceptable as a first-line diagnostic study, which is usually determined by the institution policy, availability, and physician’s preference. The simplified clinical scoring system (Table 1) and blood D-dimer levels are readily available, can be performed at the bedside, and can safely exclude the pulmonary embolism when both are negative. If either one is positive, more sensitive and specific diagnostic modalities, such as spiral computed tomography and nuclear scanning, should be considered to rule in or rule out the diagnosis of pulmonary embolism. Adil Ceydeli, M.D., M.S. Jack Yu, M.D., D.M.D., M.S. Division of Plastic and Reconstructive Surgery Medical College of Georgia Atlanta, Ga.