Remifentanil

- October 2010
- November 2006

• Some hospitals use Remifentanil as a routine analgesic option, whereas others only offer it to women who cannot have regional analgesia.
• Some hospitals include a patient information leaflet, observation chart and audit tool in their pack of Remifentanil PCA guidance. (Derby and Ninewells)
• Different concentrations of Remifentanil for bolus administration are being used. One used dose based on weight while others use fixed doses varying from 20mcg to 40 mcg (Ulster and Ninewells).
• Different strengths of Remifentanil solution are being prepared for PCA use in labour. Ulster and Ninewells use 40mcg/ml. others use 25, 50 or 100 mcg/ml. Trainees rotating through different hospitals will thus need to take particular care with different dose regimes and concentrations.
• All hospitals use a 2 minute lockout time, none use a background infusion.
• Frequency of observations is 30 minutes except in Derby where it is 15 minutes.
• All emphasise the importance of continuously monitoring SaO2 in patients on Remifentanil PCA and the importance of having a dedicated cannula.
• Only one guideline acknowledges that the drug is being used ‘off license’ –this is not uncommon for drugs in obstetric practice but Remifentanil does have a narrow therapeutic window.

• Clear advice on how to control pain if not controlled with initial setting. (Derby)
• Brief description of Remifentanil at the start of the guideline to refresh the memory of those who do not use it in their regular non obstetric practice. (Ninewells)
• One unit uses Remifentanil for women in whom regional analgesia is contraindicate AND Pethidine is unsuitable. The guideline notes that these women will usually have been identified antenatally and assessed by a consultant anaesthetist, and suggests that preparations are made as soon as they are admitted in labour.
• Inclusion of information sheet for mothers. (Ninewells and Ulster)
• Most include clear instructions for preparation of the Remifentanil solution and details of pharmacist to contact for out of hours. (Derby)
• Audit tool which would allow hospitals new to Remifentanil PCA to audit their practice.
• A tool to sign off midwive competence with Remifentanil solution preparation. (Ulster)
• Specific practical advice about importance of advising women of timing of using device (i.e. right at start of contraction).  

• The title of one patient information sheet uses the term ‘mother controlled pain relief’ – confusing, as PCA is the term that the midwife/ anaesthetist will use.
• No explicit mention of respiratory depression in information sheet for mothers considering Remifentanil for PCA (Ulster)
• Those who use weight based regime for bolus administration should caution the user to use lean body mass for obese patients to calculate dose.
• One hospital used a 20 mcg/ml concentration solution to deliver a 25 mcg bolus (1.25 ml). Instead by preparing a 25 mcg/ml concentration (1mg in 40 mls); a 1 ml bolus could be more easily delivered by the pump.
• Lack of clarity of who prepares the Remifentanil solution for the pump or makes the alteration to pump settings on the Remifentanil protocol flowchart. If the midwife is doing it, the need to call to anaesthetist should be made clear when adverse factors are noted.
• Not having a sedation score guide on the flowchart demonstrating the Remifentanil protocol.  

• The fact that Remifentanil is unlicensed for this indication was not mentioned in most information leaflets.