A recent finding of the Confidential Enquiry on Maternal and Child Health (CEMACH) 1 was that mat... more A recent finding of the Confidential Enquiry on Maternal and Child Health (CEMACH) 1 was that maternal mortality is associated with risk factors such as increased maternal age (>35 years), obesity [body mass index (BMI) > 30], late booking and social disadvantage. In the 3-year period from April 2002, there were 10 maternal deaths at Northwick Park Hospital (NPH); due to this excessive number, the unit was investigated by the Health Care Commision 2 and placed under 'special measures' by the Department of Health until October 2006.
We compared the incidence of Caesarean delivery in nulliparous women randomized to receive epidur... more We compared the incidence of Caesarean delivery in nulliparous women randomized to receive epidural analgesia with those randomized to intramuscular (i.m.) pethidine. On admission to the delivery suite in established labour, 802 nulliparae had already agreed to be randomized with respect to their first analgesia. One hundred and eighty-eight women required either no analgesia or 50% nitrous oxide in oxygen (Entonox) only. Of the remaining 614 women, 310 were randomly allocated to receive i.m. pethidine up to 300 mg and 304 to receive epidural bupivacaine. Labour management was standardized according to the criteria for active management of labour. The intention-to-treat analysis showed similar Caesarean section rates in those randomized to epidural (12%) or pethidine analgesia (13%). The difference in Caesarean rate was -1.1% with 95% confidence intervals from -6.3% to ϩ4.1%. The normal vaginal delivery rates were similar (epidural, 59%; pethidine, 61%).
We have examined the effects of lumbar extradural administration of 1% etidocaine 10 ml on somato... more We have examined the effects of lumbar extradural administration of 1% etidocaine 10 ml on somatosensory evoked potentials to posterior tibial nerve stimulation measured in the cervical extradural space. Eight patients, anaesthetized with propofol and nitrous oxide, were studied before hysterectomy and a control group received a similar anaesthetic and 0.9% sodium chloride solution 10 ml in the lumbar extradural space. Etidocaine decreased significantly overall amplitude of the evoked potentials and the amplitudes of all peaks, between 30 and 50 min after extradural injection. The effects of etidocaine on spinal cord conduction were greater than those found previously for lignocaine and bupivacaine, suggesting that it is the local analgesic of choice for inhibiting afferent conduction.
The effict.7 of fentanyl or diazepam on somatosensor?; visual and brainstem auditory evoked poten... more The effict.7 of fentanyl or diazepam on somatosensor?; visual and brainstem auditory evoked potentials were studied in 13 healthy patients schcduledjor elective surgery. Following control recordings of evoked potentials. either diazepam 20 mg or /tntangl200 p g M'US administered intravenously. Evokedpotentials were then recorded twice in the subsequent hour.
Background: Pituitary-adrenal secretion during induced hypotension for middle-ear surgery has rec... more Background: Pituitary-adrenal secretion during induced hypotension for middle-ear surgery has received little attention. Previous work failed to differentiate the effects of induced hypotension from surgical stimulation. We have undertaken a preliminary study exanking the effects of hypotension, achieved with labetalol or isoflurane, on pituitary-adrenal secretion before, during and after middle-ear surgery. Methods: Twenty-four patients were allocated randomly to 3 groups. The control group were anaesthetised with isoflurane, and normotension maintained for 30 min before hypotension was induced with isotlurane and surgery started. In the labetalol group, this drug was given i.v. to obtain a mean arterial pressure (MAP) of 60 mni Hg for 30 min before surgery and hypotension maintained with labetalol during the operation. In the isoflurane group, hypotension was induced to a MAP of 60 mm Hg for 30 min before surgery m d continued throughout the procedure.
Twelve patients undergoing abdominal surgery were studied. Alfentanil was used as the sole anesth... more Twelve patients undergoing abdominal surgery were studied. Alfentanil was used as the sole anesthetic agent in these patients via a predetermined infusion regime. In 7 cases this was sufficient but in five cases the infusion had to be supplemented. Induction was with alfentanil 100 micrograms/kg over 2 minutes, then 10 micrograms/kg/min for 10 minutes followed by 2 micrograms/kg/min for 50 minutes. After one hour the infusion rate was varied between 1-3 micrograms/kg/min. Vecuronium 0.1 mg/kg with increments of 0.025-0.075 mg/kg was used for neuromuscular blockade in nine patients, the other three patients received identical doses of pancuronium. There was no statistically significant change in blood pressure and heart rate after induction or in response to intubation and both were well maintained throughout surgery.
International journal of obstetric anesthesia, 2010
We describe a maternal death due to necrotising fasciitis caused by an extended spectrum beta-lac... more We describe a maternal death due to necrotising fasciitis caused by an extended spectrum beta-lactamase-producing Escherichia coli resistant to routinely used antimicrobial agents. Necrotising fasciitis is a rare complication of septicaemia with a high mortality. Signs of infection were insidious and masked by the use of routine analgesic agents and concurrent preeclampsia. The incidence of infection with extended spectrum beta-lactamase-producing organisms is increasing both in the United Kingdom and globally and will need to be considered in the obstetric setting. The use of the current Modified Early Warning Scores was of limited help in this case. Where there is no response to routine antibiotics within 12h, microbiological review is indicated.
International journal of obstetric anesthesia, 1999
Obstetric audit is multidisciplinary, but maternal mortality data represent the only national obs... more Obstetric audit is multidisciplinary, but maternal mortality data represent the only national obstetric anaesthetic audit currently available in the UK. Maternity and neonatal audit is progressing towards the collection of both numerator and denominator data in order to compare local, regional and national figures. Obstetric anaesthetists as a professional group play a significant role in maternity care and have in the past developed a minimum data set. Such a set now requires revision of items, agreement on definitions and integration with national projects. Since local and regional obstetric anaesthesia data collection systems are available, albeit in various manual or computerized forms, this is an achievable target. A standard maternity and neonatal data set which incorporates obstetric anaesthetic clinical items could offer a qualitative comparison of process variables and outcome, but should be under professional anaesthetic control. In addition, the process may enable profess...
We studied the effects of supplementing nitrous oxide-oxygen anaesthesia with halothane (1 MAC en... more We studied the effects of supplementing nitrous oxide-oxygen anaesthesia with halothane (1 MAC end-tidal concentration) on the motor evoked potential recorded in the extradural space of eight patients before corrective surgery for idiopathic adolescent scoliosis. The motor cortex was stimulated electrically through the scalp. An additional eight patients in whom anaesthesia was supplemented with an infusion of propofol acted as a control group. Halothane had no significant effect on the amplitude or latency of the motor evoked potential. We conclude that halothane is unlikely to alter the interpretation of motor evoked potentials recorded extradurally during scoliosis surgery.
Annals of the Royal College of Surgeons of England, 1990
A total of 40 patients undergoing scoliosis or brachial plexus surgery had bipolar electrodes ins... more A total of 40 patients undergoing scoliosis or brachial plexus surgery had bipolar electrodes inserted preoperatively in the cervical epidural space located by the 'hanging drop technique'. The angle of approach to the space was different for each spinal interspace used. Good quality recordings were obtained of SSEPs with no long-term complications and we recommend this as a safe technique.
We have studied the effects of extradural administration of 2% lignocaine at the L3-4 interspace ... more We have studied the effects of extradural administration of 2% lignocaine at the L3-4 interspace on somatosensory evoked potentials recorded in the cervical extradural space before corrective surgery for idiopathic adolescent scoliosis. Eight patients in whom the equivalent volume of 0.9% sodium chloride solution was administered into the lumbar extradural space acted as a control group. Lignocaine 2% resulted in a decrease in overall amplitude, but its main effect was a significant decrease in the amplitude of the second and third peaks, suggesting an action on the dorsal columns of the spinal cord. A significant increase in latency was found in both the lignocaine and sodium chloride groups. We conclude that the use of extradural 2% lignocaine in patients undergoing scoliosis surgery may interfere with the intraoperative monitoring of somatosensory evoked potentials.
Twenty patients who underwent elective Caesarean section received ranitidine 150 mg by mouth 8-14... more Twenty patients who underwent elective Caesarean section received ranitidine 150 mg by mouth 8-14 h, and 50 mg i.m. 90 min, before surgery. Intraoperative gastric aspiration resulted in contents with a pH greater than 2.5 and volume less than 25 ml in all patients (mean pH 6.5 (SD 0.8); mean volume 9.0 (SD 7.2) ml). Sixty patients in labour, who received ranitidine 50 mg i.m. 6-hourly, underwent emergency surgery. Half of this group received, in addition, a single preinduction dose of either 15 or 30 ml of sodium citrate 0.3 mol litre-1. A further 30 patients who remained unmedicated during labour and required emergency surgery received a preinduction dose of 15 or 30 ml of sodium citrate 0.3 mol litre-1 alone. Ranitidine medication resulted in a mean aspirated gastric volume of 31.4 (26.6) ml and pH of 5.3 (2.1); five of 30 patients had a pH less than 2.5. The addition of sodium citrate 0.3 mol litre-1 resulted in gastric pH greater than 2.5 in all patients and a mean gastric volume of 43.2 (38.3) ml. The group who received only sodium citrate 0.3 mol litre-1 had a mean pH of 5.3 (1.1) and a mean volume 122.7 (98.2) ml.
We compared the incidence of Caesarean delivery in nulliparous women randomized to receive epidur... more We compared the incidence of Caesarean delivery in nulliparous women randomized to receive epidural analgesia with those randomized to intramuscular (i.m.) pethidine. On admission to the delivery suite in established labour, 802 nulliparae had already agreed to be randomized with respect to their first analgesia. One hundred and eighty-eight women required either no analgesia or 50% nitrous oxide in oxygen (Entonox) only. Of the remaining 614 women, 310 were randomly allocated to receive i.m. pethidine up to 300 mg and 304 to receive epidural bupivacaine. Labour management was standardized according to the criteria for active management of labour. The intention-to-treat analysis showed similar Caesarean section rates in those randomized to epidural (12%) or pethidine analgesia (13%). The difference in Caesarean rate was -1.1% with 95% confidence intervals from -6.3% to ϩ4.1%. The normal vaginal delivery rates were similar (epidural, 59%; pethidine, 61%).
We studied the effects of supplementing nitrous oxide-oxygen anaesthesia with halothane (1 MAC en... more We studied the effects of supplementing nitrous oxide-oxygen anaesthesia with halothane (1 MAC end-tidal concentration) on the motor evoked potential recorded in the extradural space of eight patients before corrective surgery for idiopathic adolescent scoliosis. The motor cortex was stimulated electrically through the scalp. An additional eight patients in whom anaesthesia was supplemented with an infusion of propofol acted as a control group. Halothane had no significant effect on the amplitude or latency of the motor evoked potential. We conclude that halothane is unlikely to alter the interpretation of motor evoked potentials recorded extradurally during scoliosis surgery.
A recent finding of the Confidential Enquiry on Maternal and Child Health (CEMACH) 1 was that mat... more A recent finding of the Confidential Enquiry on Maternal and Child Health (CEMACH) 1 was that maternal mortality is associated with risk factors such as increased maternal age (>35 years), obesity [body mass index (BMI) > 30], late booking and social disadvantage. In the 3-year period from April 2002, there were 10 maternal deaths at Northwick Park Hospital (NPH); due to this excessive number, the unit was investigated by the Health Care Commision 2 and placed under 'special measures' by the Department of Health until October 2006.
We compared the incidence of Caesarean delivery in nulliparous women randomized to receive epidur... more We compared the incidence of Caesarean delivery in nulliparous women randomized to receive epidural analgesia with those randomized to intramuscular (i.m.) pethidine. On admission to the delivery suite in established labour, 802 nulliparae had already agreed to be randomized with respect to their first analgesia. One hundred and eighty-eight women required either no analgesia or 50% nitrous oxide in oxygen (Entonox) only. Of the remaining 614 women, 310 were randomly allocated to receive i.m. pethidine up to 300 mg and 304 to receive epidural bupivacaine. Labour management was standardized according to the criteria for active management of labour. The intention-to-treat analysis showed similar Caesarean section rates in those randomized to epidural (12%) or pethidine analgesia (13%). The difference in Caesarean rate was -1.1% with 95% confidence intervals from -6.3% to ϩ4.1%. The normal vaginal delivery rates were similar (epidural, 59%; pethidine, 61%).
We have examined the effects of lumbar extradural administration of 1% etidocaine 10 ml on somato... more We have examined the effects of lumbar extradural administration of 1% etidocaine 10 ml on somatosensory evoked potentials to posterior tibial nerve stimulation measured in the cervical extradural space. Eight patients, anaesthetized with propofol and nitrous oxide, were studied before hysterectomy and a control group received a similar anaesthetic and 0.9% sodium chloride solution 10 ml in the lumbar extradural space. Etidocaine decreased significantly overall amplitude of the evoked potentials and the amplitudes of all peaks, between 30 and 50 min after extradural injection. The effects of etidocaine on spinal cord conduction were greater than those found previously for lignocaine and bupivacaine, suggesting that it is the local analgesic of choice for inhibiting afferent conduction.
The effict.7 of fentanyl or diazepam on somatosensor?; visual and brainstem auditory evoked poten... more The effict.7 of fentanyl or diazepam on somatosensor?; visual and brainstem auditory evoked potentials were studied in 13 healthy patients schcduledjor elective surgery. Following control recordings of evoked potentials. either diazepam 20 mg or /tntangl200 p g M'US administered intravenously. Evokedpotentials were then recorded twice in the subsequent hour.
Background: Pituitary-adrenal secretion during induced hypotension for middle-ear surgery has rec... more Background: Pituitary-adrenal secretion during induced hypotension for middle-ear surgery has received little attention. Previous work failed to differentiate the effects of induced hypotension from surgical stimulation. We have undertaken a preliminary study exanking the effects of hypotension, achieved with labetalol or isoflurane, on pituitary-adrenal secretion before, during and after middle-ear surgery. Methods: Twenty-four patients were allocated randomly to 3 groups. The control group were anaesthetised with isoflurane, and normotension maintained for 30 min before hypotension was induced with isotlurane and surgery started. In the labetalol group, this drug was given i.v. to obtain a mean arterial pressure (MAP) of 60 mni Hg for 30 min before surgery and hypotension maintained with labetalol during the operation. In the isoflurane group, hypotension was induced to a MAP of 60 mm Hg for 30 min before surgery m d continued throughout the procedure.
Twelve patients undergoing abdominal surgery were studied. Alfentanil was used as the sole anesth... more Twelve patients undergoing abdominal surgery were studied. Alfentanil was used as the sole anesthetic agent in these patients via a predetermined infusion regime. In 7 cases this was sufficient but in five cases the infusion had to be supplemented. Induction was with alfentanil 100 micrograms/kg over 2 minutes, then 10 micrograms/kg/min for 10 minutes followed by 2 micrograms/kg/min for 50 minutes. After one hour the infusion rate was varied between 1-3 micrograms/kg/min. Vecuronium 0.1 mg/kg with increments of 0.025-0.075 mg/kg was used for neuromuscular blockade in nine patients, the other three patients received identical doses of pancuronium. There was no statistically significant change in blood pressure and heart rate after induction or in response to intubation and both were well maintained throughout surgery.
International journal of obstetric anesthesia, 2010
We describe a maternal death due to necrotising fasciitis caused by an extended spectrum beta-lac... more We describe a maternal death due to necrotising fasciitis caused by an extended spectrum beta-lactamase-producing Escherichia coli resistant to routinely used antimicrobial agents. Necrotising fasciitis is a rare complication of septicaemia with a high mortality. Signs of infection were insidious and masked by the use of routine analgesic agents and concurrent preeclampsia. The incidence of infection with extended spectrum beta-lactamase-producing organisms is increasing both in the United Kingdom and globally and will need to be considered in the obstetric setting. The use of the current Modified Early Warning Scores was of limited help in this case. Where there is no response to routine antibiotics within 12h, microbiological review is indicated.
International journal of obstetric anesthesia, 1999
Obstetric audit is multidisciplinary, but maternal mortality data represent the only national obs... more Obstetric audit is multidisciplinary, but maternal mortality data represent the only national obstetric anaesthetic audit currently available in the UK. Maternity and neonatal audit is progressing towards the collection of both numerator and denominator data in order to compare local, regional and national figures. Obstetric anaesthetists as a professional group play a significant role in maternity care and have in the past developed a minimum data set. Such a set now requires revision of items, agreement on definitions and integration with national projects. Since local and regional obstetric anaesthesia data collection systems are available, albeit in various manual or computerized forms, this is an achievable target. A standard maternity and neonatal data set which incorporates obstetric anaesthetic clinical items could offer a qualitative comparison of process variables and outcome, but should be under professional anaesthetic control. In addition, the process may enable profess...
We studied the effects of supplementing nitrous oxide-oxygen anaesthesia with halothane (1 MAC en... more We studied the effects of supplementing nitrous oxide-oxygen anaesthesia with halothane (1 MAC end-tidal concentration) on the motor evoked potential recorded in the extradural space of eight patients before corrective surgery for idiopathic adolescent scoliosis. The motor cortex was stimulated electrically through the scalp. An additional eight patients in whom anaesthesia was supplemented with an infusion of propofol acted as a control group. Halothane had no significant effect on the amplitude or latency of the motor evoked potential. We conclude that halothane is unlikely to alter the interpretation of motor evoked potentials recorded extradurally during scoliosis surgery.
Annals of the Royal College of Surgeons of England, 1990
A total of 40 patients undergoing scoliosis or brachial plexus surgery had bipolar electrodes ins... more A total of 40 patients undergoing scoliosis or brachial plexus surgery had bipolar electrodes inserted preoperatively in the cervical epidural space located by the 'hanging drop technique'. The angle of approach to the space was different for each spinal interspace used. Good quality recordings were obtained of SSEPs with no long-term complications and we recommend this as a safe technique.
We have studied the effects of extradural administration of 2% lignocaine at the L3-4 interspace ... more We have studied the effects of extradural administration of 2% lignocaine at the L3-4 interspace on somatosensory evoked potentials recorded in the cervical extradural space before corrective surgery for idiopathic adolescent scoliosis. Eight patients in whom the equivalent volume of 0.9% sodium chloride solution was administered into the lumbar extradural space acted as a control group. Lignocaine 2% resulted in a decrease in overall amplitude, but its main effect was a significant decrease in the amplitude of the second and third peaks, suggesting an action on the dorsal columns of the spinal cord. A significant increase in latency was found in both the lignocaine and sodium chloride groups. We conclude that the use of extradural 2% lignocaine in patients undergoing scoliosis surgery may interfere with the intraoperative monitoring of somatosensory evoked potentials.
Twenty patients who underwent elective Caesarean section received ranitidine 150 mg by mouth 8-14... more Twenty patients who underwent elective Caesarean section received ranitidine 150 mg by mouth 8-14 h, and 50 mg i.m. 90 min, before surgery. Intraoperative gastric aspiration resulted in contents with a pH greater than 2.5 and volume less than 25 ml in all patients (mean pH 6.5 (SD 0.8); mean volume 9.0 (SD 7.2) ml). Sixty patients in labour, who received ranitidine 50 mg i.m. 6-hourly, underwent emergency surgery. Half of this group received, in addition, a single preinduction dose of either 15 or 30 ml of sodium citrate 0.3 mol litre-1. A further 30 patients who remained unmedicated during labour and required emergency surgery received a preinduction dose of 15 or 30 ml of sodium citrate 0.3 mol litre-1 alone. Ranitidine medication resulted in a mean aspirated gastric volume of 31.4 (26.6) ml and pH of 5.3 (2.1); five of 30 patients had a pH less than 2.5. The addition of sodium citrate 0.3 mol litre-1 resulted in gastric pH greater than 2.5 in all patients and a mean gastric volume of 43.2 (38.3) ml. The group who received only sodium citrate 0.3 mol litre-1 had a mean pH of 5.3 (1.1) and a mean volume 122.7 (98.2) ml.
We compared the incidence of Caesarean delivery in nulliparous women randomized to receive epidur... more We compared the incidence of Caesarean delivery in nulliparous women randomized to receive epidural analgesia with those randomized to intramuscular (i.m.) pethidine. On admission to the delivery suite in established labour, 802 nulliparae had already agreed to be randomized with respect to their first analgesia. One hundred and eighty-eight women required either no analgesia or 50% nitrous oxide in oxygen (Entonox) only. Of the remaining 614 women, 310 were randomly allocated to receive i.m. pethidine up to 300 mg and 304 to receive epidural bupivacaine. Labour management was standardized according to the criteria for active management of labour. The intention-to-treat analysis showed similar Caesarean section rates in those randomized to epidural (12%) or pethidine analgesia (13%). The difference in Caesarean rate was -1.1% with 95% confidence intervals from -6.3% to ϩ4.1%. The normal vaginal delivery rates were similar (epidural, 59%; pethidine, 61%).
We studied the effects of supplementing nitrous oxide-oxygen anaesthesia with halothane (1 MAC en... more We studied the effects of supplementing nitrous oxide-oxygen anaesthesia with halothane (1 MAC end-tidal concentration) on the motor evoked potential recorded in the extradural space of eight patients before corrective surgery for idiopathic adolescent scoliosis. The motor cortex was stimulated electrically through the scalp. An additional eight patients in whom anaesthesia was supplemented with an infusion of propofol acted as a control group. Halothane had no significant effect on the amplitude or latency of the motor evoked potential. We conclude that halothane is unlikely to alter the interpretation of motor evoked potentials recorded extradurally during scoliosis surgery.
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Papers by B. Loughnan