A comparison of intramuscular diamorphine and intramuscular pethidine for labour analgesia: a two-centre randomised blinded controlled trial.

OBJECTIVE: Intramuscular (i.m.) pethidine is used worldwide for labour analgesia and i.m. diamorphine usage has increased in the UK in the last 15 years. This trial aims to ascertain the relative efficacy and adverse effects of diamorphine and pethidine for labour pain. DESIGN: Prospective, parallel-arm randomised controlled trial with blinding of participants, care-givers and outcome assessors. SETTING: Maternity units in two District General Hospitals in the UK. POPULATION: After written informed consent, 484 women were randomised and recruited (244 diamorphine, 240 pethidine). Inclusion criteria included women 16 years or older, established labour, singleton pregnancy, 37-42 weeks of gestation and weight 60-120 kg. METHODS: On request of i.m. analgesia, participants received either 150 mg pethidine or 7.5 mg diamorphine based on computer-generated block randomisation. MAIN OUTCOME MEASURES: Maternal-reduction in pain intensity from baseline (10-cm visual analogue scale) at 60 minutes and over the 3-hour period after drug administration. Neonatal-requirement for resuscitation and Apgar score at 1 minute. RESULTS: Diamorphine provided modestly improved pain relief at 60 minutes, mean difference 1 cm (95% confidence interval [CI] 0.5-1.5), and over the 3 hours, mean difference 0.7 cm (95% CI 0.3-1.1). However, average length of labour in women receiving diamorphine was 82 minutes longer (95% CI 39-124) and therefore they experienced more pain overall. There were no statistically significant differences in primary neonatal outcomes. CONCLUSIONS: There is a modest difference between the analgesia provided by diamorphine or pethidine for labour analgesia but diamorphine is associated with significantly longer labours.

Prescribing intramuscular opioids for labour analgesia in consultant-led maternity units: a survey of UK practice.

BACKGROUND: Intramuscular opioids are widely used for analgesia in labour. We conducted a postal survey to establish current prescribing and monitoring guidelines for intramuscular opioids in consultant-led obstetric units in the UK. METHODS: A postal questionnaire was sent between December 2005 and January 2006 to the lead obstetric anaesthetist of all 234 consultant-led obstetric units in the UK. We enquired about dose regimens of intramuscular opioids in labour and monitoring of mother, fetus and neonate. RESULTS: The response rate was 71%; 84.4% of responding units used pethidine and 34.1% diamorphine. Meptazinol and morphine were available in 13.8% and 13.2% of units respectively. Some units used more than one opioid. The choice of opioid was dictated mainly by tradition (65.3%) and familiarity (40.7%). Prophylactic antiemetics were co-administered in 73.7% of units, the most commonly used being prochlorperazine (30.5%). Vital signs were monitored in 91.6% of units: in total 10.2% measured haemoglobin oxygen saturations and 4.8% respiratory rate. Pain scores were recorded in 13.7% of units. CONCLUSIONS: When compared with previous studies the use of intramuscular diamorphine is increasing in UK consultant-led obstetric units, although pethidine remains the widely used opioid. At present this change cannot be justified by a suitably powered, randomised study comparing intramuscular pethidine with diamorphine.

Reversible posterior leucoencephalopathy syndrome in a peripartum patient.

We present the case of a multiparous parturient who developed hypertension associated with a severe headache in the immediate post-partum period. She subsequently suffered a generalised tonic clonic seizure on the fifth post-partum day. Following recovery of consciousness, she developed a left homonymous hemianopia. Apart from hypertension, headache and convulsion, she had no symptoms and no proteinuria or other biochemical or haematological changes associated with eclampsia. The magnetic resonance imaging findings were consistent with vasogenic oedema in the right posterior parieto-occipital white matter and these in turn are consistent with reversible posterior leucoencephalopathy syndrome. The differential diagnosis of convulsions in the post-partum period is discussed and the clinical and radiological features of reversible posterior leucoencephalopathy syndrome are described.

Perioperative bradycardia and asystole: relationship to vasovagal syncope and the Bezold-Jarisch reflex.

Reflex cardiovascular depression with vasodilation and bradycardia has been variously termed vasovagal syncope, the Bezold-Jarisch reflex and neurocardiogenic syncope. The circulatory response changes from the normal maintenance of arterial pressure, to parasympathetic activation and sympathetic inhibition, causing hypotension. This change is triggered by reduced cardiac venous return as well as through affective mechanisms such as pain or fear. It is probably mediated in part via afferent nerves from the heart, but also by various non-cardiac baroreceptors which may become paradoxically active. This response may occur during regional anaesthesia, haemorrhage or supine inferior vena cava compression in pregnancy; these factors are additive when combined. In these circumstances hypotension may be more severe than that caused by bradycardia alone, because of unappreciated vasodilation. Treatment includes the restoration of venous return and correction of absolute blood volume deficits. Ephedrine is the most logical choice of single drug to correct the changes because of its combined action on the heart and peripheral blood vessels. Epinephrine must be used early in established cardiac arrest, especially after high regional anaesthesia.

Thoracic epidural anaesthesia and analgesia: United Kingdom practice.

BACKGROUND: Thoracic epidural analgesia has become increasingly practised in recent years. Complications are rare but potentially serious and, consequently, careful evaluation is required before undertaking this technique. The practice surrounding this procedure varies widely amongst anaesthetists. METHODS: A postal survey to examine the practice of thoracic epidural analgesia was sent to all Royal College of Anaesthetists tutors in the United Kingdom. RESULTS: Responses were received from 240 tutors, representing a return rate of 83%. When obtaining consent for thoracic epidural cannulation, 42% of respondents mentioned risk of a dural tap complication and 11% mentioned neurological damage. Fifty percent of respondents performed epidural cannulation following induction of general anaesthesia. The practice of epidural insertion in patients with abnormal coagulation varied, although over 80% of respondents did not consider concurrent treatment with either aspirin or non-steroidal anti-inflammatory drugs a contraindication. Sterile precautions for epidural insertion also varied between anaesthetists. Postoperatively, 95% of respondents used an opioid-based bupivacaine solution for epidural infusions, and these were most commonly nursed on general surgical wards (63%). Seventy-eight percent of hospitals provided an acute pain team to review epidural analgesia. CONCLUSION: In the United Kingdom, there is little consensus in the practice of thoracic epidural analgesia relating to the issues of informed consent, epidural cannulation in patients with deranged clotting and the sterile precautions taken prior to performing epidural insertion. Most respondents use an opioid-based bupivacaine solution to provide postoperative epidural analgesia. Most hospitals in the UK now provide an acute pain service for thoracic epidural follow-up.

Randomized study of intravenous fluid preload before epidural analgesia during labour.

We performed a randomized controlled trial of the effect of intravenous fluid preload on maternal hypotension and fetal heart rate (FHR) changes in labour after the first epidural injection. Group 1 (49 women) received 1 litre of crystalloid preload. Group 2 (46 women) received no preload. No statistically significant difference was shown between the two groups for either of the outcomes. Hypotension was found in three women in group 1 and five in group 2 (P = 0.4). Deterioration in FHR pattern was found in four women in group 1 and 11 in group 2 (P = 0.08). This study has not shown a significant increase in the incidence of hypotension when intravenous preload is omitted before epidural analgesia using a low concentration of bupivacaine during labour. Because of the clinical importance of the difference in the rate of FHR deterioration between the two groups, we continue to administer preload for high-risk cases.

Analgesia after day-case knee arthroscopy: double-blind study of intra-articular tenoxicam, intra-articular bupivacaine and placebo.

Arthroscopy of the knee is performed regularly on a day-case basis. Intra-articular bupivacaine produces transient analgesia and reports of analgesia using intra-articular morphine have produced conflicting results. Non-steroidal anti-inflammatory drugs given systemically can provide effective analgesia for this procedure. In this study we attempted to determine if intra-articular tenoxicam provided useful analgesia after day-case arthroscopy. Sixty three ASA I-II patients were allocated randomly to one of three groups to receive 40 ml of a solution containing 0.9% saline (group Pla), 0.25% bupivacaine (group Bup) or tenoxicam 20 mg (group Ten). The injection was made into the knee joint at the end of surgery, 10 min before tourniquet deflation. Verbal rating and visual analogue pain scores (at rest and on knee flexion), use of analgesia, mobilization and disturbance by pain at home were recorded for the next 48 h. There were no differences between pain scores in any of the three groups when tested at rest or on movement. Less analgesia was used in the first 24 h by patients in the tenoxicam group but the difference in time to first analgesia was not statistically significant. Side effects and disturbance by pain were similar in all groups. The use of intra-articular tenoxicam 20 mg at the end of arthroscopy reduced oral analgesic requirements during the first day after operation but did not alter patients' perception of pain.

Feasibility of day case laparoscopic cholecystectomy in unselected patients.

The feasibility of day case laparoscopic cholecystectomy was assessed in unselected patients using a standard anaesthetic protocol. Postoperative pain and nausea were assessed at 6 and 24 h postoperatively (visual analogue scale, range 0-10). Thirty-two patients were studied (23 female, 9 male, mean age 49.6 years). The mean duration of surgery was 68 min. At 6 h after surgery, 10 patients (31%) had no pain at rest. For the group as a whole, the median pain score was 3 at rest (range 0-6), 4 on movement (0-9), and 5 on coughing (0-9) and eight patients (25%) were nauseated. At 24 h, 15 (46.9%) had no pain at rest. For the group as a whole, the median pain score was 1 at rest (0-7), 3 (0-6) on movement and 3 on coughing (0-9). The same eight patients were nauseated. Ten patients (31.3%) were judged fit for discharge at 6 h, and 28 (87.5%) by 24 h. There was no statistical difference in mean age or duration of surgery in those judged fit for early discharge compared to the study group as a whole. Nausea was an important factor in those unfit for discharge at 24 h. Selection criteria might improve these figures. From the results of our study, 24 h admission is a more realistic goal and will be suitable for most patients requiring laparoscopic cholecystectomy.

A comparison between the Macintosh and the McCoy laryngoscope blades.

The view of the larynx using the Macintosh laryngoscope and the McCoy levering laryngoscope was assessed in 177 adult patients. The view with the McCoy blade in the neutral position and in the position (neutral or elevated) that gave the 'best' view were recorded. The McCoy blade in the neutral position was associated with a lower incidence of grade 1 views and a higher incidence of grade 2 views than the Macintosh blade. There was no difference in the incidence of grade 3 views. When views for each patient using the different blades were compared, the McCoy blade in the neutral position produced a worse view than the Macintosh blade (p < 0.0001). The view obtained with the McCoy blade in its 'best' position and the Macintosh blade were similar. In the 152 patients in whom the vocal cords were seen using the Macintosh blade, the view was worse using the McCoy blade in its 'best' position more often than it was better (p = 0.06). In 25 patients, the vocal cords could not be seen with the Macintosh blade; in these patients the view was better with the McCoy blade (the cords were visible) on 14 occasions and worse in one (p = 0.001). We conclude that the McCoy blade in its neutral position does not behave identically to the Macintosh blade. The McCoy blade is a useful aid to difficult intubation but should not replace the Macintosh blade as the first choice laryngoscope.

Forum. An evaluation of the levering laryngoscope.

This study was undertaken to evaluate the effect of the levering laryngoscope on the view obtained at laryngoscopy. Two hundred and ten consecutive patients who required tracheal intubation were studied. The view at laryngoscopy with the levering laryngoscope blade in the neutral and elevated positions was recorded. In patients in whom there was a Cormack and Lehane grade 3 view of the larynx with the blade in the neutral position, elevation of the levered tip of the blade significantly improved the visualisation of the larynx. In patients where the view of the larynx was grade 1 or 2 with the blade in the neutral position, elevation of the levered tip often (23%) resulted in the view being impaired. This was not a clinical problem as the blade could simply be returned to the neutral position. The levering laryngoscope is a useful additional aid to laryngeal visualisation.