Objective: Pulmonary complications are one of the most common iatrogenic complications of surgery requiring general anesthesia. These complications include respiratory infection, respiratory failure, atelectasis, pneumothorax, pleural effusion, bronchospasm, aspiration pneumonitis, pulmonary embolism, and acute respiratory distress syndrome. During general anesthesia, endotracheal tubes (ETT) are designed to protect the airway with an inflated cuff. Current ETT do not provide complete protection, however, due to longitudinal creases of the cuffs that allow fluids pooling above the cuff to be aspirated. The goal of this project is to assess risk factors for postoperative pulmonary dysfunction in a high-risk population undergoing endoscopic endonasal surgery (EES) of the skull base.
Methods: This is a retrospective study of 100 patients who underwent EES in January 2023 through June 2023. All patients undergoing skull base surgery regardless of age, gender, or diagnosis were included. Data variables including BMI, duration of surgery, duration of intubation, and volume of blood loss were assessed as potential risk factors for postoperative pulmonary dysfunction. Pulmonary complications that developed within 60 days post-surgery were included in the study. Data are reported as mean +/- SD. A two-sample t-test was performed to compare duration of surgery and intubation, BMI, and blood loss in those that did and did not develop pneumonia. A chi-square test was performed to examine the relationship between postoperative intubation status and pneumonia.
Results: 30% of patients developed clinical pulmonary complications including increased oxygen requirement (13), pneumonia (9), respiratory failure (3), atelectasis (3), and pulmonary embolism (2). Patients that developed pneumonia had a longer duration of surgery (M= 8.75, SD= 3.85 hours) than did those that did not (M=5.53, SD=2.8 hours); (p=.002). In addition, patients that developed pneumonia had a longer duration of intubation (M=57.25, SD=83.03 hours) than did those that did not (M=5.62, SD=3.28 hours); (p= <.001). There was no significant difference in BMI between patients that developed pneumonia (M=31.07, SD=9.20) and patients that did not develop pneumonia (M=29.50, SD=6.89); (p= 0.53). Lastly, there was no significant difference in blood loss between patients that developed pneumonia (M=933.33, SD=810.09 mL), and patients that did not develop pneumonia (M=748.96, SD=1069.42 mL); (p=0.62). Those that developed pneumonia were more likely to leave the operating room intubated than patients that did not develop pneumonia (p<0.001). In patients that developed pneumonia, 8/9 had a tracheostomy, ETT, OG/NG, PEG, or duotube placed post-surgery with their individual postoperative complications including CSF leakage and respiratory distress. 7/9 patients with pneumonia had no preoperative history of pulmonary disease; two patients had a history of sleep apnea.
Conclusion: The incidence of postoperative pulmonary complications in patients undergoing endoscopic endonasal surgery of the skull base is significant and may be linked to silent aspiration in the majority of patients. Targeting risk factors for postoperative pulmonary dysfunction should have a meaningful impact on outcomes. Greater attention needs to be paid to prevention of intraoperative aspiration.