Correlation of Preexisting Medical Conditions and Postoperative Respiratory Complications in Morbidly Obese Patients Following Bariatric Surgery

Abstract

Obesity is a major problem in the United States, with more than 60% of the total adult population being classified as overweight or obese. It is a multifactorial disease that includes genetic, socioeconomic, psychological, cultural, preexisting disease, and aging/metabolic predisposing factors. One of the treatment modalities for morbidly obese patients is bariatric surgery before severe complications develop. Surgery itself further puts these patients at risk for cardiovascular and respiratory complications. Previous literature by Chung et al. and Brooks- Brunnstated that obesity was predictive of postoperative respiratory complications (PRC). A recent study by Blouw et al. concluded that the incidence of PRC is lower than previously stated. <p>A problem was identified when three bariatric surgical patients were reintubated postoperatively. These caused great concern to the anesthesia provider because some bariatric patients have “difficult airways” to begin with. If there were a method that could correlate preexisting medical conditions with respiratory complications following bariatric surgery, this airway crisis might be avoided. This possibility of prediction validates the need for this current research to examine preexisting medical conditions for correlations with postoperative respiratory complications following bariatric surgery. <p>This was an IRB-approved, retrospective study with a systematic sampling method. Data w'ere collected from 252 charts of subjects who underwent elective bariatric surgery. Preexisting medical conditions, demographic data, and postoperative respiratory complications were obtained from the medical records. Postoperative respiratory complications were defined as any of the following that occurred in the first 24 hours postoperatively: oxygen saturation decrease to less than 90% and subsequent need for advanced oxygen management; hypoxia and or respiratory acidosis confirmed by arterial blood gas measurement; atelectasis, infiltrations, pneumonia or pleural effusion confirmed by chest radiography; and continued intubation or reintubation required postoperatively. The descnptive data were presented with the use of standard deviations and means. Data analysis was conducted by using Fisher Exact Chi Square Test tor determining the correlation of the independent and dependent variables. <p>The study results indicated that the incidence of postoperative respiratory complications was 12% among the study subjects. The vast majority of all the subjects, 99.2%. had at least one or more co-morbidity. Preoperative co-morbidities of respiratory symptoms, respiratory diseases, obesity-related related symptoms, and preoperative cardiovascular conditions were statistically significant in correlation with postoperative respiratory complications. <p>In this study, high BMI and preexisting respiratory diseases correlated with three of four types of postoperative respiratory complications. Preexisting cardiovascular conditions correlated with two of four types of postoperative respiratory complications. The patient characteristics of age and gender, and other co-morbidities such as obesity-related symptoms, respiratory symptoms, and preoperative abnormal chest x-rays correlated with one of the four types of postoperative respiratory complications. <p>This study demonstrated a correlation between preexisting medical conditions such as high BMI, respirator}' disease, cardiovascular conditions, age, gender, obesity-related symptoms, respiratory symptoms, and abnormal chest x-rays and the development of postoperative respiratory complications. Despite a correlation, this study showed that the risk of developing postoperative respiratory complications was minimal (12%) in this high-risk population. This study further concluded that the exhaustive, multidisciplinary approach in preparing a morbidly obese patient for bariatric surgery, routine prophylactic respiratory treatment for the first 48 hours postoperatively, continuous oxygen delivery, and the institution of continuous positive airway pressure ventilation postoperatively may have contributed to the low incidence of postoperative respiratory complications.