Does initial clinical impression predict cardiopulmonary exercise testing performance?

Recognising frailty in patients pre-operatively is important as they have higher mortality and are less likely to return to baseline functional status post surgery [1]. Valid and reliable assessment of functional capacity is an important part of pre-operative evaluation [2]. Initial clinical impression is considered useful to identify frail patients during pre-operative assessment,though little research exists to validate this. By comparison, cardiopulmonary exercise testing (CPET) reliably predicts postoperative outcomes.
MethodsDuring pre-operative assessment in our CPET clinic, an initial clinical impression for each patient was prospectively formed by two experienced clinicians before history taking. Each patient was judged ‘frail’ or ‘not frail’ by initial subjective assessment. Clinical notes were reviewed and patients considered either ‘fit’ or‘unfit’ based on severity of comorbidities. This information was compared against anaerobic threshold (AT), postoperative risk prediction by CPET and ASA status. Data were analysed using the Chi-square automatic interaction detection decision tree technique method (SPSS).
ResultsIn total, 133 patients who had CPET testing in 2016 were included (age range 45–89, 44% female, 56% male). The majority (64%) of patients were scheduled for colorectal surgery. Four patients were unable to perform CPET and 18 (14%) had an indeterminate AT. Twenty-six percent of patients who were frail by initial clinical impression were fit by notes review. Of those with an AT < 11 mlO2.kg-1.min-1, 35% were deemed not frail by clinical impression whereas 39% were frail; the remainder of patients had an indeterminate AT. Of those with an AT > 11 mlO2.kg-1.min-1, 26% were deemed frail by clinical impression; 28% of patients who were not frail by clinical impression were intermediate/high risk by CPET criteria.
DiscussionThere appears to be poor agreement between first impression ‘eyeballing’by clinicians and CPET performance. Approximately one-third of patients deemed fit by first clinical impression or notes review were higher risk by CPET criteria. This study suggests that snapshot clinical opinions of frailty status gained in the first minute of patient encounter often result in inaccurate assessment of patient risk. We have shown that many patients who are deemed fit on clinical impression have CPET results that put them in a higher risk group postoperatively. Caution is warranted when using ‘gutinstinct’ as a predictor of peri-operative risk assessment.
References1. O’Neill B, Batterham A, Hollingsworth A, Durrand J, Danjoux G. Do firstimpressions count? Frailty judged by initial clinical impression predictsmedium-term mortality in vascular surgical patients. Anaesthesia 2016;71: 684–91.2. Stokes J, Wanderer J, McEvoy M. Significant discrepancies exist betweenclinician assessment and patient self-assessment of functional capacityby validated scoring tools during preoperative evaluation. PerioperativeMedicine 2016; 5: 18.
ApprovalsREC Approval obtainedR&D department Approval obtainedAudit department Advice not soughtCaldicott Guardian Advice not soughtConsent None