Research project

Service evaluation of surgical mortality and morbidity risk prediction by preoperative cardiopulmonary exercise testing

Respiratory and Sleep Sciences
Philip Smith
Training location
Queen Alexandra Hospital, Portsmouth


All surgical procedures involve some level of risk. The pre-operative process of weighing up the relative benefits and risks of a procedure has developed over time to take into account a wide range of information about the patient, including the results of a cardiopulmonary exercise test (CPET). Previous studies demonstrate the benefits of using CPET results to stratify the risk of patients and identify those in need of further management. CPET is a maximal test where a patient exercises on a treadmill or bike until exhaustion. While they do this, equipment monitors the responses of their body including measurements such as their heart rate and rhythm, breathing patterns, work rate, and the level of oxygen and carbon dioxide they breathe in and out. Previous research has shown that poor performance in CPET was associated with a higher risk of complications and mortality during and after various types of surgeries. As a result, it is now increasingly used to tailor risk predictions for individual patients and recommend suitable post-surgical care.


This service evaluation retrospectively analysed perioperative CPET results at Queen Alexandra Hospital in Portsmouth and follow-up outcomes of patients to investigate how well CPET parameters predict post-operative outcomes.


Results showed that the main perioperative CPET parameters of peak VO2 index, anaerobic threshold index, and the ventilatory equivalent for carbon dioxide(VE/VCO2) were associated with some post-operative outcomes. However, this varied between different outcomes, measures, and across different surgical specialities. As such, despite the limitations of many CPET studies, CPET is predictive of post-operative outcomes in this patient cohort.

Last updated on 4th October 2022