Assessing analgesic efficacy after operative delivery: is it how you ask the question?
M Davidson, KN Litchfield, M Broom
Princess Royal Maternity, Glasgow Royal Infirmary, Glasgow, UK
Introduction: Postoperative review of women after operative delivery is a routine part of the obstetric anaesthetist's role. It allows assessment of adequacy of analgesia and should be structured around departmental guidelines ensuring local standards of care1.Numerical rating scores (NRS) are one form of assessment. However, what one woman considers the "worst pain you can imagine" may be vastly different to that of another woman, limiting its use. Additionally, asking about pain and pain scores after operative delivery may adversely affect patient reports of their postoperative experiences when compared to other assessment modalities such as comfort scores2.In our institution, we previously used an NRS for comfort (NRS-C). We then moved to an NRS for pain (NRS-P) but now use a functional score (FS). Our aim was to assess if using an FS allowed a better evaluation of analgesic efficacy.
Methods: A retrospective review of data from routinely collected post-operative assessments was performed. All operative deliveries performed under regional anaesthesia where a post-operative pain assessment had been performed were included from Sept 2015 to Sept 2017 (3846 mothers).
Z-score with 2-tailed p-value was used to test statistical significance. An NRS-C was used where comfort score of 0 equated to no comfort and 10 totally comfortable. A conventional NRS-P used pain score of 0 as no pain and 10 as worst pain imaginable. The functional score assessed a woman’s ability to “do what you wanted to for yourself and your baby”.
Results: Using an NRS-C, 48% of women reported a score ≥7 and 13% reported a score of ≤3. This correlated with NRS-P which showed 48% of women reported scores of ≤3 and 15% reported scores of ≥7. For poor analgesia outcomes reported by women (NRS-P ≥7 and NRS-C ≤3) there was no statistically significant difference between these groups (p=0.26). When assessing functional score, 73% and 25% of women reported ‘completely’ and ‘mostly’ respectively. Only 2% of women reported ‘very little’ or ‘not at all’. Significantly fewer women reported poor analgesia outcome using FS when compared to NRS-C and NRS-P (p=0.002).
Discussion: If considering an NRS-P of ≥7, or NRS-C ≤3 as a poor analgesic outcome, this was reported by 14% of women in these groups overall. However, without altering analgesic regime and moving to functional score, only 2% reported a poor score. Though not a validated score, we believe that assessing functional scores allows us to evaluate important and more relevant end-points for post-operative analgesia outcomes.