Abnormal routine pre-operative test results and their impact on anaesthetic management: An observational study.
Indian Journal of Anaesthetics 2018;62:23-8. DOI: 10.4103/ija.IJA_223_17
Presented by: Dr Benjamin O’Donovan, ST4 Anaesthetics
In spite of guidelines from the ASA and NICE, and a lack of evidence for ‘routine’ pre-operative investigations they are still frequently carried out. These investigations may identify previously unknown abnormalities resulting in changes to pre-operative management. This study aimed to assess the prevalence of abnormal test results and their impact on the peri-operative management of patients undergoing elective surgery.
Design & Setting
An observational prospective study, in a tertiary care teaching hospital.
414 consecutive patients aged 12 years or older, male or female, attending preassessment clinic for non-cardiac surgery were used.
- Pregnant patients
- Bedridden or immobile patients (unable to assess body weight)
- Patients under the age of 12 years old
- ASA grade
- Grade of surgery (NICE classification)
- All investigations and results prior to being declared fit for surgery were noted including:
- Haemoglobin less than 10g/dL
- Platelets less than 100
- Elevated blood sugar
- Abnormal TFTs
- Newly diagnosed comorbidities from investigations were noted.
NB: New diagnoses of hypertension were not counted
- An abnormal result was said to be ‘impactful’ if it resulting in referral, delay, further investigations, retesting or changes in anaesthetic management plan.
- This was said to be a significant impact if the resulting change was in the perioperative anaesthetic management.
- An abnormal but potentially expected result leading to a change in management was not counted.
- 345 (11.6%) of results were abnormal
- 56 abnormalities had an impact
- 20 had a significant impact.
NNI for significant impact was 21 and detecting new abnormality was 28. Average
- Over half of patients in the study have abnormal test results
- 8% of tests have an impact on patients
- 67% of tests have significant impact.
- National Journal
- Prospective study
- Appropriate study power calculation
- Largely reasonable exclusion criteria
- Positive subject to investigate in terms of rationalising healthcare expenditure.
- Observational study
- Single centre
- Unclear if protocol for requesting pre-operative investigations
- 12 seems an odd age for cut off of lower limit
- Not affecting peri-operative management doesn’t necessarily mean no significant patient impact.
We over investigate our patients by the parameters of impact/significant impact set out in this study.
Potential for impact
Given that this study indicates that patients are over investigated at pre-operative assessment there would be the potential for significant cost-saving by reducing the number of investigations requested.