Indirect effects of shielding on cardiovascular fitness and physiological reserve in preoperative assessment during the COVID-19 pandemic

In response to the COVID-19 pandemic, the UK Government introduced shielding for the 2.5 million vulnerable people in our society as determined by the presence of certain medical conditions, those aged > 70 and pregnant women. Those shielding were advised to stay at home at all times and avoid face-to-face contact. As the pandemic has evolved and lockdown restrictions have proved instrumental in achieving control, it is worth considering the potential adverse effects of protracted shielding for patients undergoing major elective surgery, such as reduction in their cardiopulmonary fitness. Methods At Worthing Hospital, we have continued our cardiopulmonary exercise testing (CPET) service with appropriate precautions during the pandemic, to aid risk stratification of patients undergoing work-up for planned major surgery. A peak oxygen delivery (VO2 peak) of < 15 ml.kg-1.min-1 and an anaerobic threshold (AT) < 10.1 ml.kg-1.min-1 [1] are associated with a higher risk of peri-operative complications, with a failure to achieve AT reflecting a very high-risk group [2]. We report a retrospective review of CPET testing for 6 months from the start of shielding (16 March 2020) compared with data from the previous 22 months. Patients were listed for major urological, colorectal and upper GI surgery with no change in referral criteria between the two periods and similar population characteristics. Results The lockdown group had a lower VO2 peak, with fewer patients reaching AT (results summarised in Table 1). Discussion Given the short time frame, it seems unlikely that an increase in number and severity of comorbidities affecting our local population would explain a decline in fitness. Change in lifestyle, including reduced exercise, is a plausible explanation for our findings. This highlights the importance of recognising the indirect physical effects of shielding, and should be considered when taking on high-risk surgical patients, estimating demand for ICU beds and the potential impact on outcomes. This small dataset may not be generalisable widely, and we would welcome other services experiences;however, this does serve to highlight the importance of educating our vulnerable population with regard to the importance of diet and exercise during ongoing lockdown restrictions, to help maintain their fitness in preparation for major surgery.