INCIDENCE AND RISK FACTORS OF RESPIRATORY COMPLICATIONS IN ABDOMINAL SURGERY IN OBESE PATIENTS

Abstract

Obesity is associated with concomitant pulmonary comorbidities such as asthma, respiratory hyperreactivity, obstructive sleep apnea, hypoventilation syndrome, pulmonary hypertension, that in combination with restrictive lung physiology and perioperative opioids administration can lead to a higher probability of postoperative pulmonary complications (PPC) in this population. But recent research data is controversial. The aim of our work was to evaluate the incidence of respiratory complications after elective abdominal operations in obese patients and to determine if the level of preoperative functional status is a predictor of their development. In a retrospective-prospective study, an analysis of hospital PPC (pneumonia, reintubation, prolonged ventilator support more than 48 hours, pleural effusion, respiratory failure) was performed in 770 patients with BMI>30 kg/ m2, to whom operations on the abdominal organs and the anterior abdominal wall were carried out in the period from 2007 to 2018. The incidence of pneumonia was compared with values predicted by the ACS-NSQIP calculator. The connection of PPC with the initial level of functional status of patients (independent, partially dependent, completely dependent, MET4) and type of surgical intervention (laparoscopy, laparotomy, superficial surgery) were determined. Statistical processing of the results was performed using Student t-test, Mann-Whitney U-test, ?2 criterion, Fishers exact criterion, regression analysis. Pneumonia was observed in 2.2% - 2.5% of patients, that coincided with the predicted by ACS-NSQIP calculator risk of 2.4% [0.1; 7.2] (p>0.05). Total incidence of PPC was 7.9% in the retrospective group and 6.1% in the prospective group (p 48 hours, from 1% to 2.5% for pleural effusion and respiratory failure (p>0.05). More than 96% of patients in the prospective study (n = 490) were functionally independent, had good functional capacity and incidence of PPC at 5.7% level. In partially dependent patients this value increased to 17.6% (OR 3.54; 95% CI 0.96 - 13.07; =0.0578), and in patients with MET<4 - up to 13.3% (OR 2.46; 95% CI 0.53 - 11.42; =0.2518). Laparoscopic technique of surgery contributed to the reduction of respiratory complications probability and they occurred in 4.3% of patients, while after laparotomy PPC were recorded in 10.2% of patients (OR 2.54; 95% CI 1.20 - 5.36; =0.0148). So, we found that the influence of obesity on the development of postoperative respiratory complications in abdominal surgery is slightly exaggerated, and the laparotomy technique of surgery is more important risk factor for PPC.

Keywords

• obesity
• respiratory complications
• risk factors