Overall mortality of COVID-19 is variable and has been reported to be between less than 1% and 7%. Many authors around the world also reported data on hospitalization rate, need for intensive care unit (ICU) care and need for mechanical ventilation in SARS-CoV-2 infected patients. To provide anesthetic and surgical care to SARS-CoV-2 infected patients, many health workers have to organize surgical platforms, personal protections and in-hospital trajectories to prevent dissemination and cross-contamination. However, no data has been published on the surgical need of these patients, their postoperative outcomes and the impact they may have on the operating room. Postoperative outcomes in SARS-CoV-2 infected patients seem to be variable. Expected benefits from a surgical procedure may be different in this population if their postoperative mortality is higher than expected. The association between preoperative characteristics and postoperative outcomes in this population has to be better defined. There is a need to better quantify these and better inform use of surgical resources during a pandemic. To address this knowledge gap, the investigators propose to conduct a multicenter observational cohort study in SARS-CoV-2 infected patients undergoing a surgical procedure, as well as in those who have recovered from COVID-19.
METHODS Objectives
Primary: To describe postoperative outcomes in patients with COVID-19 undergoing a surgical
procedure and measure the association between presence of symptoms and postoperative
outcomes.
Secondary: To describe postoperative outcomes in patients undergoing a surgical procedure
after they have healed from COVID-19 and measure the association between time from first
positive test and postoperative outcomes.
Tertiary: To compare outcomes between symptomatic and asymptomatic COVID-19 patients
undergoing a surgery with those who have healed from it.
Exposure variables:
For the primary objective, the exposure of interest will be the presence of symptoms at time
of surgery. For the secondary objective, the exposure will be the length of time between
first COVID-19 positive test and the date of surgery. For the tertiary objective, the status
of the disease will be our exposure of interest.
Variable definitions:
All COVID-19 variables will be based on the first day of diagnosis (either clinical or by
RT-PCR from either an oronasopharyngeal swab or an endotracheal specimen). The investigators
will also capture asymptomatic SARS-CoV-2 carrier. Recovery at surgery will be defined as
having two negative SARS-CoV-2 PCR tests between the last positive one and the surgery, or 1
negative test and a clinically significant period without symptoms between the last positive
test and the negative one or no negative test but considered as recovered by the clinical
team because of complete symptoms resolution.Criteria for "healed" status changed in November
2020 and were less restrictive (as detailed in table 1 of the protocol). No minimal or
maximal delay will be applied between SARS-COV-2 infection and surgery for inclusion.
Surgical disease will be defined as the one reported by the surgeon. Surgeries will be
further categorized into the following categories: neurosurgical (head, neck and spine),
cardiac, thoracic, major vascular (intrathoracic and/or intra-abdominal), non-vascular
abdominal (laparotomy or laparoscopy), urogenital (urology and/or gynecology), non-spine
orthopedics, peripheral vascular, ENT and other. Any neurosurgical, cardiac, thoracic, major
vascular or non-vascular abdominal surgery will be defined as a major surgery. The
investigators will capture the surgical approach (minimally invasive or invasive) and the
urgent nature of the procedure. Minimally invasive surgery will be defined as a one that does
not need to open an anatomical cavity (laparoscopy, thoracoscopy, endoluminal). Urgency of
surgery will be defined as one that needs to be done within 24 hours (emergent or urgent), or
can wait for more than 24 hours (non-urgent).
The investigators will measure hospital survival. The investigators will also capture
survival up to 30 days and 6 months using regular hospital follow-up. The investigators will
use existing definitions for the postoperative pulmonary complications outcome. Non-pulmonary
infectious complications will be defined as any infection that needed antibiotics for more
than 72 hours. Acute kidney injury will be defined by the creatinine difference of the
KDIGO-AKI criteria. Myocardial infraction and stroke will be defined as reported by treating
physicians. Mechanical ventilation will be defined as any mechanical support (non-invasive or
invasive). All 30-day outcomes will include any day with the outcome and the 30-day organ
dysfunction free days will use existing definitions.
Sample size:
The investigators plan a convenient sample size depending on the number of patients and
center included. Inclusion will start on the 13th of March 2020.
Analyses:
Primary objective The investigaors will first conduct descriptive analyses of baseline
characteristics and outcomes of COVID-19 confirmed patients based on the presence of symptoms
at the time of surgery (symptomatic versus asymptomatic). The investigators will report
descriptively the following outcomes in both patients' population: proportion of patients
with pulmonary complications, thromboembolic complications, non-pulmonary infectious
complications, need for a new postoperative ICU admission, mean hospital length of stay,
30-day mechanical ventilation free-days and 30-day organ dysfunction free days. . To evaluate
if presence of symptoms is associated with hospital survival in SARS-COV2 infected patients
for the primary analysis, investigators will fit a multivariable Cox model that will include
presence of symptoms, preoperative hospitalization, preoperative respiratory support need
(invasive mechanical ventilation, oxygen therapy, no oxygen), urgency of surgery, importance
of surgery (major versus minor) as independent variables and a frailty factor as a center
random effect. If too few events our observed, investigators will limit covariables in their
model.
Secondary objective The investigators will report descriptively patients who have recovered
by categorizing them based on the time since first positive test (categorized as 0-4 weeks,
4-8 weeks and > 8 weeks). The investigators will report the same outcomes as previously
mentioned. To analyze the effect of recovery time on postoperative survival, the
investigators will fit a similar multivariable survival model . The investigators will
include time since first positive COVID-19 test, preoperative hospitalization, preoperative
respiratory support need (invasive mechanical ventilation, oxygen therapy, no oxygen),
urgency of surgery, importance of surgery (major versus minor) as independent variables and a
frailty factor as a center random effect. Investigators will explore non-linear relationship
between time and the outcome.
Tertiary objective The investigators will report descriptively patients who have recovered
and asymptomatic COVID-19 patients. To compare if those two groups of patients are different
regarding hospital survival, the investigators will fit a multivariable survival model that
will include status (recovered versus asymptomatic carrier), preoperative hospitalization,
preoperative respiratory support need (invasive mechanical ventilation, oxygen therapy, no
oxygen), urgency of surgery, importance of surgery (major versus minor) as independent
variables and a frailty factor as a center random effect.
Inclusion Criteria:
- all patients undergoing a surgery with either a SARS-CoV-2 clinical suspicion based on
reported symptoms during the pandemic (fever, myalgia, fatigue, cough, dyspnea,
respiratory failure, diarrhea, vomiting, abdominal pain) or without any suggestive
symptoms AND a SARS-CoV-2 confirmed infection with RT-PCR before surgery or within 72
hours after surgery. Patients who have recovered from SARS-CoV-2 infection will also
be included. All patients up to 30th day of April 2021 will be included.
Exclusion Criteria:
- none
Centre Hospitalier de l'Université de Montréal (CHUM)
Montréal, Quebec, Canada
François-Martin Carrier, MD, FRCPC, Principal Investigator
Centre hospitalier de l'Université de Montréal (CHUM)