There were very few differences in outcomes following emergent laparoscopic and open appendectomy during the COVID-19 pandemic compared to the year prior to the pandemic among hospitals participating in the ACS-NSQIP. Previous studies using the ACS-NSQIP database have shown seasonal variations in outcomes after surgery,16 and this is compounded by the varying waves of the COVID-19 pandemic throughout 2020. By comparing the ACS-NSQIP data by quarter, we attempted to minimize the effects of these variations. We compared a variety of 30-day post-surgical outcomes including death, readmission, blood transfusions, prolonged ventilator requirement, sepsis, shock, and reoperations during each quarter of 2019 to the corresponding quarter of 2020. The only outcomes that we found to be more likely in 2020 when compared to the same periods of 2019 were septic shock in the first quarter (January, February, March), rates of complicated appendicitis in the fourth quarter (October, November, December), and reoperations in the third quarter (July, August, and September). Given the limited number of reoperations (1.23% of appendectomies in 2020 in comparison to 0.85% in 2019), reoperations still represent a very small number of total appendectomies. Of note, reoperations were more likely in the first quarter of 2020 than the first quarter of 2019, although this period was largely before COVID-19 was declared a pandemic. Overall, this study demonstrates the resiliency of surgical systems throughout the United States. Amid disruptions in workflow, limited PPE and available hospital beds, and the threat of contracting and spreading COVID-19, surgeons and the systems they function in were able to maintain surgical outcomes consistent with those observed pre-pandemic.
In addition to binary complications and outcomes, we compared other data points including length of stay, days from admission to operation, preoperative white blood cell count, and total operative time. Operative time was found to be significantly increased in the first three quarters of 2020 when compared to 2019. However, across all three quarters, the difference in mean operative time was under 3 minutes, and the clinical significance is unclear considering the absence of an associated difference in outcomes. During the early stages of the pandemic, there were concerns about potential adverse outcomes due to patient’s delaying arrival to the hospital due to fear of contracting COVID-19 in a healthcare setting as well as the possibility of in-hospital delays due to waiting for PCR testing results to return, strained hospital resources, additional precautions by staff to avoid exposure, and continually evolving infection prevention protocols. We found that the time from admission to operation in 2020 was longer in the first quarter (0.30 days in the first quarter of 2019 vs 0.38 days in the first quarter of 2020, p = 0.032), but not in the last three quarters. While the first quarter of 2020 is largely pre-COVID, it includes March 2020, likely the period of greatest disruption and rapid change for many hospital systems. Contributing factors to this observed increase in time until operation in the first quarter of 2020 may have included overwhelmed emergency departments in areas experiencing COVID-19 case surges, decreased availability of staff as systems restructured, increased time required to set-up and turn over rooms to prevent COVID-19 transmission, as well as the time required to perform COVID-19 PCR testing on patients prior to operations, a process that evolved as hospitals created new testing protocols for patients undergoing surgery. It is important to consider that our data does not address whether there was an increase in medical-only management of appendicitis, which has the potential to affect the observed time from admission to operation as well. While there was a slight increase in length of stay in the first quarter of 2020 in comparison to the same quarter of 2019, possibly reflective of the increase in days from admission to operation observed in this same period, this finding was not statistically significant, and overall length of stay was not significantly different between 2019 and 2020 in our data.
Previous research has suggested an increase in cases of complicated appendicitis during the early stages of the COVID-19 pandemic, perhaps a consequence of delayed presentation due to fear of contracting COVID-19 in hospitals.10,13,14,17 An international meta-analysis found 21 studies evaluating the rate of complicated appendicitis (involving abscess, perforation, or peritonitis). 7,474 patients during the pandemic were compared to 18,107 cases before the pandemic, with 26.6% of patients having complicated appendicitis during the pandemic compared to 22.2% before the pandemic.10 In the present study, there was a significantly higher frequency of complicated appendicitis in the fourth quarter of 2020 compared to 2019, but not in any of the other time periods. The first few months of the pandemic were when the largest disruptions in care would have been predicted to occur as well as the time of the greatest fear of contracting COVID-19 in hospital settings. Thus, the lack of significant changes in cases of complicated appendicitis in the first three quarters of the 2020 suggests that increased complicated appendicitis cases in the setting of delays care early in the pandemic may have been less prevalent then previously assumed. The marked increase in complicated appendicitis during the fourth quarter of 2020 compared to 2019 is perhaps unexpected given that there were no other significant differences in any of the variables we analyzed between the fourth quarters of 2019 and 2020. While the possibility of COVID-19-related delays in care may potentially have contributed to this observed increase in cases of complicated appendicitis in October, November, and December of 2020, it is also interesting to consider that non-operative, antibiotic-only management of uncomplicated appendicitis increased over the course of the pandemic.4,10,18 Thus increased rates of complicated appendicitis in the fourth quarter of 2020 may be the result of an increased number of cases of uncomplicated appendicitis being treated non-operatively and thus no longer included in appendectomy outcome data, or alternatively, increased complicated appendicitis cases in patients who failed conservative treatment that progress to complicated appendicitis requiring surgical intervention. While our dataset only allows for analysis of operative cases of appendicitis, there may be an opportunity for additional study to determine the effects of increased antibiotic-only treatment of appendicitis and whether this trend continues in 2021 and onwards.
Other factors that might correlate with disease severity possibly related to delays in care include sepsis, septic shock, and preoperative white blood cell (WBC) count. There was an observed increase in septic shock in the first quarter of 2020. This might be due to delays in care associated with disruptions to healthcare systems and fears of acquiring COVID-19 in hospital settings early in the pandemic; however, the lack of associated significant changes in complicated appendicitis, and mortality makes it challenging to understand the specific cause of the increases in cases of septic shock during the first quarter of 2020. When comparing preoperative WBC count in quarters 1, 3, and 4, there was no significant difference between the WBC count of patients receiving appendectomies in 2019 versus in 2020. In contrast, the second quarter of 2020 was modest increase in preoperative white blood cell count (13.09 in 2019 vs 13.24 in 2020, p = 0.030). It is not possible to form any conclusions from WBC count alone as it is just one of many factors used to assess the severity of appendicitis along with physical exam, imaging, and additional laboratory findings, and it is not a factor in differentiating complicated from uncomplicated appendicitis.19,20 It is possible that the increased operative time in the first three quarters of 2020 versus 2019 might reflect increased operative complexity,17 but this would be impossible to conclude without more specific data as there are many other factors that may lead to increased operative time. The minimal difference in outcomes during the early COVID-19 pandemic indicates that surgeons were able to maintain consistent outcomes regardless of any increase in complexity, demonstrating the ability of surgical systems to adapt effectively despite increased systemic stressors.
This study has several important limitations that may affect the interpretation and generalizability of these findings. First, there are inherent limits to the ACS-NSQIP database – only a subset of hospitals participate in this database, and thus demographic differences between NSQIP-participating hospitals and non-participating hospitals may affect the generalizability of these findings. While the NSQIP dataset has the advantage of its large scale, the de-identified nature of the data and absence of many clinical data points makes it more challenging to observe local trends and further analyze different sub-types of appendicitis. The COVID-19 pandemic evolved rapidly over the course of 2020, and affected different geographic regions at different times, thus both the local effects of COVID-19 and short-term effects (particularly events over a few week) may not be realized in this analysis of national data broken down quarterly. Additionally, it’s important to recognize the uniqueness of the 2020 COVID-19 outbreak. One may not assume that the outcomes from this initial phase of the pandemic will be applicable to future COVID-19 waves or other potential disruptions to the surgical system.