Timing of intravenous patient-controlled remifentanil bolus during early labour.

BACKGROUND: Remifentanil labour analgesia is superior to nitrous oxide but less potent than epidural analgesia. The short onset and offset times of effect suggest that the timing of the bolus in the contraction cycle could have importance. We hypothesised that administering a remifentanil bolus during contraction pause would improve analgesia in early labour. METHODS: With permission from the ethical committee and the National Authority of Medicines, 50 parturients with uncomplicated singleton pregnancies and informed consent participated in a double blind cross-over study. Intravenous doses of 0.4 µg/kg remifentanil with 1-min infusion times were used during two study periods lasting six to eight contractions. Remifentanil and saline syringes were attached to two patient-controlled devices, one of which administered the bolus immediately after a trigger and the other targeted to start 140 s before the next contraction. The parturients assessed contraction pain, pain relief, sedation and nausea. Oxygen saturation (SaO(2)) pulse and blood pressure were recorded. SaO(2)<95% was the indication for oxygen supplement. RESULTS: Forty-one parturients were included in the analyses. Because of the period effect, pain and pain relief scores were analysed separately for each of the study periods. The mean pain and pain relief scores were similar during the two different dosing regimens. Side effects, the need for supplemental oxygen, SaO(2) and haemodynamics were similar. In a subgroup with long and regular contractions, however, delayed boluses were associated with lower pain scores. CONCLUSIONS: Administering a remifentanil bolus during the uterine contraction pause does not improve pain relief.

Intravenous remifentanil vs. epidural levobupivacaine with fentanyl for pain relief in early labour: a randomised, controlled, double-blinded study.

BACKGROUND: We hypothesised that intravenous patient-controlled analgesia (IV PCA) with remifentanil could provide as satisfactory pain relief for labour as epidural analgesia. METHODS: Fifty-two parturients with singleton uncomplicated pregnancies were randomised to receive either IV PCA with remifentanil or epidural analgesia with 20 ml levobupivacaine 0.625 mg/ml and fentanyl 2 microg/ml in saline. The PCA dose of remifentanil was given over 1 min with a lockout time of 1 min. The dose was increased starting from the bolus of 0.1 microg/kg and following a dose escalation scheme up until the individual-effective dose was reached. The parturients assessed contraction pain (0-10), pain relief (0-4), sedation and nausea during 60 min. RESULTS: Forty-five parturients were included in the analysis. The median cervical opening was 4 cm before the study and 7 cm after the study. The median pain scores were 7.3 and 5.2 during remifentanil and epidural analgesia, respectively (P=0.009). The median pain relief scores were 2.5 and 2.8 (P=0.17). There was no difference between the groups in the proportion of parturients who discontinued due to ineffective analgesia, nor in the proportion of parturients who would have liked to continue the given medication at the end of the study. Sedation and low haemoglobin oxygen saturation were observed more often during remifentanil analgesia. Foetal heart rate tracing abnormalities were as common in both groups. CONCLUSIONS: In terms of pain scores, epidural analgesia is superior to that provided by IV remifentanil. However, there was no difference in the pain relief scores between the treatments.

The effects of pre-emptive epidural sufentanil on human immune function.

BACKGROUND: Surgical stress and general anaesthesia suppress immune functions, including natural killer cell (NK) activity. This suppression could be attributed, at least in part, to the effect of opiates. METHODS: Twenty patients undergoing abdominal hysterectomy received epidural sufentanil (50 microg) either before (pre-emptive) or at the end (control group) of surgery. Post-operative pain relief was provided using sufentanil from a patient-controlled epidural analgesia (PCEA) system. Systemic immunity was assessed by determining leucocyte counts, NK cell counts and activity, lymphocyte response to mitogen stimulation, and secretion of pro-inflammatory cytokines. RESULTS: In the pre-emptive group there was a significant decrease in NK activity on the first and third post-operative day (P < 0.05) compared with baseline values and on the third postoperative day (P < 0.05) compared with the control group. The number of total leucocytes and neutrophiles increased in both groups post-operatively, but no differences were found in the levels of mononuclear lymphocyte populations or in their mitogen responses. Interleukin-6 (IL-6) concentration increased in both groups after the operation. In addition, at the end of the surgery the IL-6 level was greater in the control group than in the pre-emptive group. Interleukin-1 (IL-1) levels had decreased significantly at the end of surgery and 4 h later compared with baseline levels in the pre-emptive, but not in the control group. CONCLUSIONS: Pre-emptive epidural sufentanil during combined propofol and isoflurane anaesthesia had minor effects on the immune response after hysterectomy. The lower production of pro-inflammatory cytokines (IL-1, IL-6) in the pre-emptive group compared with the control group is beneficial, but its clinical importance remains to be determined.

Pre-emptive effect of epidural sufentanil in abdominal hysterectomy.

BACKGROUND: Experimental studies suggest pre-emptive administration of analgesics is effective but clinical evidence is less convincing. METHODS: Forty-one patients undergoing abdominal hysterectomy were allocated randomly in a double-blind fashion to receive sufentanil 50 micrograms via a lumbar epidural catheter before or at the end of surgery. RESULTS: Sufentanil consumption from a patient-controlled epidural analgesia (PCEA) system and numerical pain scores at rest and during movement over the initial 72 h were similar in the two groups. When the study period was divided into five time intervals, sufentanil consumption in the pre-emptive group was significantly less than in the control group between 8 and 16 h after surgery (P = 0.04). Furthermore, the number of failed bolus attempts from the PCEA device was significantly lower and patient satisfaction was significantly better in the pre-emptive group during the 72 h of PCEA treatment (P < 0.05). In addition, the median decrease in ACTH and cortisol on the first postoperative morning relative to baseline values was greater in the pre-emptive group than in the control group (P < 0.05). In subjects who had a Pfannenstiel incision, touch and pain sensitivity in the wound area were less in the pre-emptive group over the first 4 postoperative days (P < 0.05). CONCLUSIONS: We conclude that pre-emptive analgesia with epidural sufentanil was associated with a short-term sufentanil-sparing effect, and could have reduced stress hormone responses and wound sensitization after abdominal hysterectomy.

Post-tonsillectomy pain: a prospective, randomised and double-blinded study to compare an ultrasonically activated scalpel technique with the blunt dissection technique.

Thirty-two patients participated in a study to compare the use of an ultrasonically activated scalpel (Harmonic scalpel) for tonsillectomy on one side and a blunt dissection tonsillectomy on the other. Pain scores at rest and on swallowing expressed as the area under curves (AUC) during the 10 h after surgery, intra-operative blood loss and the need for electrocoagulation for haemostasis were significantly higher on the blunt dissection side than on the Harmonic scalpel side (p < 0.05). However, pain scores expressed as AUC at rest, on swallowing, the day's least, average and worst levels of pain, and the day's worst otalgia during the second week after surgery were significantly higher on the Harmonic scalpel side than on the blunt dissection side. In conclusion, we found that Harmonic scalpel tonsillectomy was associated with decreased severity in pharyngeal pain on the day of the operation but increased pharyngeal pain and otalgia during the second postoperative week.