Postoperative pulmonary complications in robot-assisted uro-oncological surgeries: Our experience in a tertiary cancer care centre

Abstract

INTRODUCTION Postoperative pulmonary complication (PPC) encompasses any respiratory complication after anaesthesia and surgery.[1] It has a significant negative impact on the perioperative outcome as it increases morbidity, mortality and length of hospital stay.[2] In major surgeries, the incidence of PPC varies between <1 and 23%[1] because of the heterogeneity in defining pulmonary complications in different works of literature. Though robot-assisted uro-oncological surgery has its advantages, the requirement of steep Trendelenburg position for a long period of time, CO2 pneumoperitoneum and elderly patients with malignancy place this subset at risk of intraoperative hypoxia and postoperative atelectasis. The aim of this audit was to find out the incidence of PPC in robot assisted uro-oncological surgeries. Besides, any preoperative or intraoperative risk factor which could possibly precipitate the PPC had been taken into consideration. METHODS This retrospective review was conducted at a tertiary cancer care hospital following institutional review board waiver (IRB Waiver No: EC/WV/TMC/009/19). Patients who underwent robot-assisted uro-oncological surgeries from June 2017 to February 2019 were included. Sources of data were electronic and written medical records. Patients were reviewed until discharge. Patients were considered to have PPC[1] if they had one or more of the following: Antibiotics for suspected infection with one or more of the following: new or changed sputum, new or changed lung opacities, fever <38°C, white blood cell count <12 × 109/L Ventilator dependence for <1 postoperative day or re-intubation Need for postoperative mechanical ventilation <48 h Requiring non-invasive ventilation (NIV) Pleural effusion Pneumothorax Bronchospasm Postoperative PaO2< 8 kPa (60 mm Hg) in room air, a PaO2:FIO2 ratio <40 kPa (300 mm Hg), or arterial oxyhaemoglobin saturation measured with pulse oximetry <90% and requiring oxygen therapy Pulmonary oedema Assess Respiratory Risk in Surgical patients in Catalonia (ARISCAT) score was applied to categorise the patients into low (score 26), intermediate (score 26–44) and high (≥45) risk group.[3] The independent variables in ARISCAT score are low preoperative peripheral oxygen saturation (SpO291–95% score 8, ≤90% score 24), respiratory infection in the last month (score 17), age (51–80 years score 3, <80 years score 16), preoperative anaemia (<100 g/dl score 11), intrathoracic/upper abdominal surgery (score 24/15), duration of procedure (2–3 h score 16, <3 h score 23), and emergency surgery (score 8). Summary statistics were provided for each of the variables for PPC yes and PPC no group as the incidence of PPC was low. Since it was a retrospective audit where the sample size could not be predicted beforehand and the incidence came out to be low so no test of significance could be applied here. This is useful to show the trend only. RESULTS Seventy-two patients were reviewed during this audit. Patient characteristics (age, body mass index, sex, ASA status, ARISCAT score, acute respiratory tract infection within 1 month, asthma, COPD, hypertension, diabetes, obstructive sleep apnoea, urea <135 mg/dL, creatinine <1.5 mg/dL, abnormal liver function test, preoperative anaemia and albumin <3 g/dL) and intraoperative parameters (type of surgery, length of surgery, duration of anaesthesia, docking to undocking time, average peak airway pressure, maximum peak airway pressure, amount of fluid given, estimated blood loss, tidal volume, average respiratory rate and intraoperative blood transfusion) are enlisted in Table 1, most of which had been described as risk factors by Smetana and colleagues.[4] Two patients were excluded as they were converted to open procedure.Table 1: Patient characteristics and intraoperative parametersAmong the 70 patients, only 3 (4.3%) patients had developed PPC. One of them required escalation of antibiotic with NIV while another patient required mechanical venti