key: cord-0845675-46dqkmfd
authors: Mavrothalassitis, Orestes; Pirracchio, Romain; Fong, Nicholas; Lazzareschi, Daniel; Sharma, Anshuman; Vaughn, Michelle T.; Mathis, Michael; Legrand, Matthieu
title: Outcome of surgical patients during the first wave of the COVID-19 pandemic in US hospitals
date: 2021-10-01
journal: Br J Anaesth
DOI: 10.1016/j.bja.2021.09.023
sha: e1be41c18f94c404f3c7a3d8d75a2032f06f70d5
doc_id: 845675
cord_uid: 46dqkmfd

nan

pandemic period (period of a three-phase pandemic model as described below). A random effect for the institution ID and week number and an interaction term between the pandemic period and the COVID-19 regional severity quartile was included in the model. Surgical case volume trends across all included MPOG institutions were identified using joinpoint regression. The identified joinpoints were used to split the study into three periods of surgical volumes: surgeries performed from 6 January 2020 through 15 March 2020 were defined as "pre-pandemic," surgeries performed during the nadir surgical volume period from 16 March 2020 through 5 April 2020 were defined as "nadir pandemic," and surgeries performed from 6 April 2020 through 28 June 2020 were defined as "restart pandemic" (Supplemental Figure 1) . States in the US were distributed into quartiles based on cumulative COVID-19 mortality per capita on 30 June 2020 to assess regional COVID-19 severity (Supplemental Figure 2) .

A total of 618,251 surgeries across 36 MPOG institutions were analysed. The average weekly surgical case volume in the cohort was 35,876 cases per week at baseline during the week of 6 January 2020 and dropped the week of 16 March 2020, before rising again the week of 6 April 2020.

There was heterogeneity in weekly surgical volume decline from baseline to nadir between institutions, with the most severely affected institution having a 99% decrease from baseline surgical volume and the least severely affected institution having a 49% decrease from baseline surgical volume (Supplemental Figure 3 ).

When compared with pre-pandemic surgical patients, nadir pandemic surgical patients tended to be younger (53 (17) yr vs. 56 (18) yr, p<0.001), less likely to be outpatient (39.1% vs. 57.1%, p<0.001), and more likely to be undergoing emergency surgery (8.8% vs. 4 .2%, p<0.001) ( Table 1) . They were more likely to have comorbid conditions, including arrhythmia, coagulopathy, congestive heart failure, hypertension, and renal failure, and had higher 30-day mortality (hazard ratio 1.75, 95%CI 1.61-1.93).

After adjustment, there was no difference in 30-day surgical mortality during the nadir pandemic period when compared to the pre-pandemic period (hazard ratio 1.09, 95% CI 0.77-1.41), nor was there a significant difference between pandemic nadir and restart periods. There was an increase in J o u r n a l P r e -p r o o f 30-day surgical mortality at hospitals from COVID-19 regional severity quartiles Q4, Q3, and Q1 during the nadir pandemic period when compared to the pre-pandemic period, with the greatest increase at hospitals in the highest COVID-19 regional severity quartile [30-day surgical mortality hazard ratio 2.18 (95%CI 1.94-2.45) in Q4, 1.43 (1.07-1.93 ) in Q3, 1.13 (0.90-1.43 ) in Q2, and 1.42 (1.13-1.80) in Q1]. After risk adjustment, there was no significant difference in 30-day surgical mortality at hospitals within any of the COVID-19 severity quartiles during the nadir pandemic period when compared to the pre-pandemic period (Supplemental Table 1 ).

Previous studies have shown worse postoperative outcomes in individual patients with COVID-19 infection 5, 6 , even in settings with low overall incidence of perioperative COVID-19 infection 7,8 . However, there has been little evidence on the outcome of patients undergoing surgery during the early phase of the pandemic regardless of the infective status. The lack of association of early pandemic COVID-19 regional severity with adjusted surgical mortality in our study would suggest that despite any health system limitations in perioperative staff, intensive care unit beds, ventilators, medications, testing, or risk of viral transmission, outcomes of patients undergoing surgery were not compromised even in states with the highest COVID-19 severity.

Our study has limitations. Due to the need to preserve anonymity of the MPOG institutions meeting inclusion criteria of this study, it was not possible to ascertain the COVID-19 mortality rate within individual institutions being studied, or their precise geography; as such, some granularity as to COVID-19 regional severity was compromised by only associating institutional surgical volumes and patient outcomes with national quartiles of COVID-19 mortality rates. COVID-19 severity in this study was evaluated based on 30 June 2020 COVID-19 statistics. It is possible that this assessment of COVID-19 severity does not correlate completely with early COVID-19 regional severity. Furthermore, only mortality was explored as an outcome, while other potentially meaningfull outcomes (e.g. postoperative infections) were not explored. Although the MPOG consortium includes a mix of private and public hospitals from across the US, we had an over-representation of centres from states most severely impacted. Furthermore, county hospitals might be underrepresented.

To conclude, patients undergoing surgery during the early phase of the pandemic had a greater burden of comorbidities, were more frequently undergoing emergency surgeries and had higher 30day mortality, with the highest surgical mortality noted at hospitals with highest COVID-19 regional severity. However, after adjusting for patient risk factors, surgical mortality was not different across regions of varying COVID-19 regional severity, suggesting that this finding was related to an inherently sicker patient population undergoing higher-risk surgeries, rather than impact from regional COVID-19 severity per se. Taken together, these findings support that the quality of care and safety of anaesthesia, surgery and perioperative medicine were maintained during the early phase of the pandemic.

Global guidance for surgical care during the COVID-19 pandemic -PubMed

non-essential medical, surgical, and dental procedures during COVID-19 response 2020

Response of US hospitals to elective surgical cases in the COVID-19 pandemic

Preoperative Score to Predict Postoperative Mortality (POSPOM): Derivation and Validation

Factors Associated With Surgical Mortality and Complications Among Patients With and Without Coronavirus Disease 2019 (COVID-19) in Italy

Mortality and pulmonary complications in patients undergoing surgery with perioperative SARS-CoV-2 infection: an international cohort study

Mortality after surgery with SARS-CoV-2 infection in England: a population-wide epidemiological study

Surgical activity in England and Wales during the COVID-19 pandemic: a nationwide observational cohort study

The authors gratefully acknowledge the valuable contributions to protocol and final manuscript review by the following MPOG collaborators

Shital Vachhani

Administrative, technical, or material support: all authors Supervision: ML Age, yr (SD)

1%) 5,088 (13.1%) 0.94

ASA physical status 1-2 161,643 (47.5%) 13853 (39.6%)

6%) 7,507 (19.3%)

.9%)

5%)

3%)

Society of Anesthesiologists; CI, confidence interval

The authors would like to thank the staff of the MPOG coordinating centre for the development of the technical, regulatory, and organizational infrastructure required for the establishment and sustainment

The authors declare no conficts of interest.

Funding was provided by departmental and institutional resources at each contributing MPOG site. In addition, partial funding to support underlying electronic health record data collection into the