Incidence and Risk Factors for Postoperative Pulmonary Complications in Head and Neck Cancer Surgery Patients: a Prospective Observational Study

AIMS & OBJECTIVES OF THE STUDY:

The objective of this study is to identify the incidence and risk factors of Postop Pulmonary Complications in Head and Neck Cancer surgeries.

STUDY DESIGN AND METHODOLOGY:

This will be a prospective observational study, which will be done over a period of one year (Upto1000 patients) after approval from ethics committee. It will be carried out at Tata Memorial hospital, Mumbai after the patient’s written informed consent (if IEC approves waiver of written informed consent then consent will not be taken). This study is a prospective observational study as a part of dissertation in Tata Memorial Hospital. Once after approval from the IEC, a data till November 2019 end will be analyzed and will be presented as a thesis for MD (Anaesthesia).

The clinical data of all patients who undergo head and neck cancer surgeries with or without free flap reconstruction at a single institution during a 1 year period from January 2019 to December 2019 will be analyzed in a prospective fashion. Administration of anaesthesia and reversal of neuromuscular blocking drugs will be carried as per the institutional routine practice and at the discretion of anaesthesiologist in charge. Postoperatively, the patient will be shifted to the post anesthesia care unit with or without the Endotracheal or tracheostomy tube. On the morning of postoperative day 1 (POD 1), the patients will be extubated in recovery and observed for another two hours. Later they will be shifted to the ward if their vitals and hemodynamics are stable. The patients will be followed up in the wards, till the patient is discharged or develops a PPC (by one of the research team member) and the postoperative pulmonary complications (PPC) will be recorded. The PPCs which will be recorded are pneumonia, aspiration, atelectasis, & pulmonary edema, till the date of discharge.

Also any patient in ward with saturation less than 88 % and persistent tachycardia more than 100/min that shifted to PACU will be followed up for PPCs.

Once the patients are diagnosed to have PPCs, they will be considered to have reached the end point of the study.

VARIABLES:

Preoperative:demographics and the following variables will be recorded: Serum albumin level, body mass index (calculated as weight in kilograms divided by the square of height in meters), cigarette smoking and tobacco consumption history (pack-years), and alcohol consumption history (units per week). We will also record the primary cancer, neoadjuvant chemotherapy, pre-operative tracheostomy.

Intraoperative: ventilatory strategy, tracheostomy, blood loss, fluid replacement, blood transfusion, duration of surgery, antibiotic prophylaxis, will be recorded Postoperative: mechanical ventilation, type of surgery- primary closure or reconstructive procedures and PPCs

PRIMARY OUTCOME:

The primary outcome will be pulmonary complication. This is defined as pneumonia or aspiration, atelectasis, & pulmonary edema. Pulmonary infection will be diagnosed if at least 2 of the following criteria are met: persistent (i.e., at least 24 hours’ duration) temperature rise above 37.5°C, purulent sputum with a definite increase in volume (20%), radiologic evidence of new shadowing on chest radiograph, and/or persistent (i.e., for 2 or more days) localized signs on chest examination (crackles, bronchial breathing, wheeze, and/or pleural rub). The presence of atelectasis will be diagnosed radiologically. Aspiration will be diagnosed radiologically and by history. Pulmonary edema diagnosed by history, clinical examination and radiologically.

INCLUSION CRITERIA:

All male & female patients (aged 18-75 years) who undergohead and neck cancer surgeries including base of skull and oral cavity, with American Society of Anaesthesiologists physical status (ASA-PS) I & II

EXCLUSION CRITERIA:

1. Presence of preoperative respiratory diseases,
2. ASA-PS III & above,
3. Age < 18yrs and > 75 yrs.
4. Thyroid, Parotid surgeries

STATISTICAL ANALYSIS:

Since the study will be done over a period of twelve months, there is no sample size.

Continuous variables will be analyzed using independent t-test or Mann Whitney U test as per the distribution of the data for continuous variables. Categorical variables will be analyzed using Chi-square test or Fisher’s exact test. P-value < 0.05 will be considered statistical significant. Risk factors of PPCs will be analyzed using univariate and multivariate binary regression with robust estimates to calculate odds ratio (OR) and their 95% confidence interval. A manual stepwise forward logistic regression will be used toextract univariate independent variables. A p value ≤ 0.2 by univariate analysis will be used as the criterion for choosing variables to be included in the model for multivariate analysis. A p value <0.05 is considered statistically significant.