Lay summary: High Altitude Pulmonary Edema (HAPE) is a potentially fatal disease of altitude, in which the lungs can become filled with fluid. In this article we explore the mechanisms causing this condition and how it can be viewed as a condition of a mismatch between current environment and evolutionary experience.

Introduction The coronavirus disease 2019 (COVID-19) pandemic led to hospitals in the UK substituting face-to-face (FtF) clinics with virtual clinic (VC) appointments. We evaluated the use of virtual two-week wait (2-ww) lower gastrointestinal (LGI) clinic appointments, conducted using telephone calls at a district general hospital in England. Methods Patients undergoing index outpatient 2-ww LGI clinic assessment between 1 June 2019 and 31 October 2019 (FtF group) and 1 June 2020 and 31 October 2020 (VC group) were identified. Relevant data were obtained using electronic patient records. Compliance with national cancer waiting time targets was assessed. Environmental and financial impact analyses were performed. Results In total, 1,531 patients were analysed (median age=70, male=852, 55.6%). Of these, 757 (49.4%) were assessed virtually via telephone; the remainder were seen FtF (n=774, 50.6%). Ninety-two (6%, VC=44, FtF=48) patients had malignant pathology and 64 (4.2%) had colorectal cancer (CRC); of these, 46 (71.9%, VC=26, FtF=20) underwent treatment with curative intent. The median waiting times to index appointment, investigation and diagnosis were significantly lower following VC assessment (p<0.001). The cancer detection rates (p=0.749), treatments received (p=0.785) and median time to index treatment for CRC patients (p=0.156) were similar. A significantly higher proportion of patients were seen within two weeks of referral in the VC group (p<0.001). VC appointments saved patients a total of 9,288 miles, 0.7 metric tonnes of CO2 emissions and £7,482.97. Taxpayers saved £80,242.00 from VCs. No formal complaints were received from patients or staff in the VC group. Conclusion Virtual 2-ww LGI clinics were effective, safe and were associated with tangible environmental and financial benefits.