Background: Colonoscopy is a common outpatient procedure often requiring anaesthesia/sedation. Pain is often reported as main complaint, and thus we designed a prospective observational trial of PCA remifentanil, but, aware that peri-procedural anxiety may be an issue we used the State Trait Anxiety Inventory (STAI) to limit the procedure by excluding those with the highest anxiety and analysing only those, who may benefit from an analgesic-only technique
Aim: To assess an analgesic-only technique for outpatient colonoscopies and to analyse the influence of anxiety on pt. assessment of anaesthetic approach
Materials and Methods: Under routine monitoring (ECG, SpO2 and NIBP) and oxygen 3 l/min suppl. PCA remifentanil (concentration 20 μg/ml) was administered in a 0.4 μg/kg bolus followed by PCA doses 0.2 μg/kg; lock-out 1 min; no background infusion, no anxyolytics. We noted HR, BP, SpO2, responsiveness acc. to Ramsay scale, pain acc. to 1-10 VAS scale, discomfort on a 0-3 scale and all side effects and complaints.
Results: Of 100 ASA I-II pts. (32 M, 68F) 9 were excluded due to STAI score of 70+, 3 - due to poor bowel preparation. Analysis incl. 88 pts (24M, 63F); aged 20-75 (median: 57); weight 50-115 kg (median 72); mean colonoscopy duration - 34 mins (range: 14-70). Remifentanil use: mean ind. dose 29 μg (range: 20-46); total dose - 31-756 μg (mean: 199 μg); mean no. of PCA impulses - 21and of effective PCA impulses - 7 (ranges 1-133 and 1-20, resp.). No significant BP, HR and RR changes were observed. 22 pts reported pain (2 of VAS 10) but refused change of technique defining pain as anxiety. Mean VAS: 3.75. 41 pts. reported discomfort. We observed no differences between M and F as to STAI score (p=0.13); VAS score (p=0.1) and discomfort (p=0.067). Assessment of method was 2.94 on a 2 to 5 scale. Pre-procedural STAI score correlated with VAS and discomfort scores (p=0.03) and with total no. of ineffective PCA doses (p=0.0017). 63 patients stated that they would rather sleep through the procedure, but 2only 7 refused the same regimen in the future. Results show that pts with a high STAI score assess the method as poor and suggest that not pain, but anxiety is the main issue during colonoscopy.
Conclusions: An analgesic-only technique for colonoscopy is poorly accepted; anxiety is confused with pain. The technique is acceptable for pts with tthe lowest anxiety level; the remaining pts. require sedation.