A49 An Audit of Post-operative Analgesia Requirements after a Supratentorial Craniotomy with and without an Intra-operative Scalp Block

Abstract

Post-operative pain after a craniotomy can be a common problem and is described as moderate to severe and is often more than expected (1,2,3,4). It is for this reason, and concern of drug side-effects that it is often poorly managed (1,2). Some studies describe the significant effect of a scalp block (2,4,5,). A recent systematic review concluded that overall the evidence does suggest an analgesic effect but it was unable to give any firm recommendations (1).

The aim of the study was to assess whether the peri-operative insertion of a scalp block, in patients having a supra-tentorial craniotomy, altered post-operative analgesia requirements.

From June to November 2011, 40 patients that had a supra-tentorial craniotomy were retrospectively identified from the Neurosurgical Theatre Logbook. The case notes were requested and an audit proforma completed.

Exclusion criteria included a post-operative Glasgow Coma Score less than 15 and patients on chronic pain medications.

All scalp blocks involved the use of 0.5% Levobupivicaine, with over 75% receiving 20mls. 50% of scalp blocks had the addition of 1/200,000 Adrenaline.

Intra-operatively, 40% of the scalp block group received an opioid for analgesia, whereas 75% of the non-scalp block group received an opioid for analgesia. In recovery, 30% of both audit groups received an opioid.

Post-operatively, by 4 hours, 50% of the non-scalp block group received an opioid for analgesia. 85% of the non-scalp block group had an opioid by 12 hours.

Post-operatively, it was not until 10 hours that 50% of the scalp block group received an opioid. At 14 hours, it was still only 50% of the scalp block group that had received an opioid.

There does appear to be a role for the use of an intra-operative scalp block in all patients having a supra-tentorial craniotomy. There is a difference in intra-operative and post-operative use of opioids between the two groups, although there was no difference in the recovery room.

The scalp block has many advantages as a technique. It is considered a low risk procedure, easy to insert and has less side effects. It provides effective analgesia without compromising neurological function. As the study represents our local patient population, we will use it to inform practice in our department.