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Biomedical subjects

A Holdcroft

Publications and source records attributed to A Holdcroft.

At least 19 recordsLinked to original sources
PubMed2007

Analgesia with sevoflurane during labour: i. Determination of the optimum concentration.

BACKGROUND: Sevoflurane has favourable physical qualities for inhaled analgesia during labour pain. The aim of this preliminary study was to identify its optimum concentration. METHODS: In this open-labelled escalating-dose study, 22 parturients in labour self-administered sevoflurane at 10 contractions using an Oxford Miniature Vaporiser. The inspired concentration was increased by 0.2% after each contraction from 0% to 1.4% or decreased if sedation occurred. Visual analogue scores (0-100 mm) for pain intensity, pain relief, sedation, mood and coping were measured after each contraction. RESULTS: The median (IQR [range]) pain relief and sedation scores increased from 44 (43-56 [4-93]) mm and 55 (43-56 [0-98]) mm at 0.2% sevoflurane, to 74 (72-78 [50-80]) mm and 71 (71-73 [33-97]) mm at 1.2% sevoflurane, respectively. Pain relief scores did not show any significant increase above 0.8% whilst sedation continued to increase, with excessive sedation occurring at 1.2% sevoflurane. No significant changes in other scores were measured. CONCLUSIONS: We concluded that the optimal sevoflurane concentration in labour was 0.8%. This concentration allows a safety margin and balances the risk of sedation with the benefit of pain relief in labour.

Adaptation, Psychological↗
PubMed2007

Analgesia with sevoflurane during labour: ii. Sevoflurane compared with Entonox for labour analgesia.

BACKGROUND: We determined the optimal inspired sevoflurane concentration for use during labour as 0.8% in our previous study. This study compared sevoflurane at a concentration of 0.8% and Entonox((R)) (nitrous oxide 50%: oxygen 50%) for analgesia during labour in 32 healthy parturients. METHODS: Each mother underwent two open-label, three-part sequences in random order, Entonox-sevoflurane-Entonox or sevoflurane-Entonox-sevoflurane. In each part the agent was self-administered during 10 contractions. A 100 mm visual analogue scores for pain relief and sedation was completed immediately after each contraction. RESULTS: Two patients withdrew during administration of sevoflurane (because of its odour) and five during Entonox (requesting epidural analgesia). Of the remaining women, data were available for analysis from 29 participants: median (IQR [range]) pain relief scores were significantly higher for sevoflurane 67 (55-74 [33-100]) mm than for Entonox 51 (40-69.5 [13-100]) mm (P<0.037). Nausea and vomiting were more common in the Entonox group [relative risk 2.7 (95% CI 1.3-5.7); P=0.004]. No other adverse effects were observed in the mothers or babies. There was significantly more sedation with sevoflurane than with Entonox {74 (66.5-81 [32.5-100]) and 51 (41-69.5 [13-100]) mm, respectively; P<0.001}. Twenty-nine patients preferred sevoflurane to Entonox and found its sedative effects helpful. CONCLUSIONS: We conclude that self-administered sevoflurane at subanaesthetic concentration (0.8%) can provide useful pain relief during the first stage of labour, and to a greater extent than Entonox. Although greater sedative effects were experienced with sevoflurane, it was preferred to Entonox.

Adult↗
PubMed2006

A national survey of obstetric anaesthetic handovers.

The handover of patient information between shifts enables continuity of care and increases patient safety. We surveyed UK practice during handovers in obstetric anaesthesia. A questionnaire was sent to 239 lead consultant obstetric anaesthetists to record routine practice in their unit and individual opinion about handover procedures. Responses were received from 168 anaesthetists, a 70% response rate. Handover policies were available in 10% of units. Most (76%) responding units had an allocated time for handover. In most units (76%), the duration of handover was reported as being < 15 min but the actual duration and depth of any discussion involved were not specified. Handovers were rarely documented in writing (7%). Consultant anaesthetists were most likely to be present at the morning handover and few handovers were multidisciplinary. Four percent of units reported critical incidents following inadequate handovers in the past 12 months. We identify features in handover procedures that could be improved.

Anesthesia, Obstetrical↗
PubMed2003

Postpartum headaches: summary report of the National Obstetric Anaesthetic Database (NOAD) 1999.

The National Obstetric Anaesthetic Database was established in 1998 to support collection of national data on obstetric analgesia and anaesthesia. The first year's project aimed to determine the incidence, characteristics, contributing factors and management of postpartum headaches with anaesthetic interventions. A total of 65348 women were reported to have had anaesthetic interventions. There were individual records of 404 women in whom postdural puncture headache (PDPH) was diagnosed (47 mild, 134 moderate, 202 severe and 21 unspecified) and 571 in whom headache was not related to dural puncture (315 mild, 176 moderate, 44 severe and 36 unspecified). Recognised dural puncture occurred in 165 women (41%), 130 (79%) during labour. Placement of spinal catheters on dural puncture in 51 women did not influence headache severity. Abdominal compression used to test the diagnosis of PDPH was only positive in 56/186 parturients (30%). Epidural blood patch was performed in 240 women with PDPH, of whom 101 women (42%) received their first blood patch within two days of delivery. The incidence of headache ranged from 1.1% to 1.9% between all anaesthetic techniques but increased to 11% for women receiving multiple regional anaesthetics. The predominant characteristics of PDPH were limitation of daily activity (n=305, 75%), severity (moderate/severe) and a postural element (n = 325, 80%), all significantly different from headache from other causes (P = 0.001). Shoulder/neck stiffness (n=172, 43%) was the commonest symptom associated with PDPH.

Journal Article↗
PubMed2002

Magnetic resonance imaging in preeclampsia and eclampsia complicated by visual disturbance and other neurological abnormalities.

This study describes magnetic resonance imaging findings in women presenting with neurological complications associated with preeclampsia and eclampsia. One eclamptic and two preeclamptic women were studied after presenting with postpartum neurological events. In two women the brain increased in size on the initial follow-up images, following the same pattern seen in normal pregnancy. In the other woman, the brain was decreased in size at 13 days postpartum but increased in size at six weeks postpartum. This initial reduction in brain size may reflect the resolution of cerebral oedema resulting from underlying pathological processes.

Journal Article↗
PubMed2001

Cannabinoids - from plant to patient. 5 April 2001, London, UK.

The active constituents of cannabis (predominantly cannabinoids and possibly flavonoids) are more effective than a single cannabinoid in reducing muscle spasticity in a multiple sclerosis animal model. Possible interactions include both pharmacokinetic and pharmacodynamic effects. Synthetic cannabinoids with agonist or antagonist/inverse agonist effects are available with high affinity for cannabinoids receptors. Pharmaceutical products that block their uptake and metabolism may enhance the endocannabinoid system. Government- and charity-funded clinical trials of cannabis are proceeding in pain, both acute (MRC multicenter trial) and chronic, and multiple sclerosis (MRC and Multiple Sclerosis Society multicenter trials). The design of these trials should enable evidence to be presented to regulatory bodies documenting the medicinal uses of standardized cannabis plant material.

Journal Article↗
PubMed2000

Sex and oestrous cycle differences in visceromotor responses and vasopressin release in response to colonic distension in male and female rats anaesthetized with halothane.

Visceromotor responses and vasopressin release before and after colonic visceral distension were compared between male (n=5 (n=4 for vasopressin)) and female rats and between females during the oestrous cycle (proestrus n=6, oestrus n=5, metestrus n=5, diestrus n=6) at a controlled depth of anaesthesia. Pre-stimulation vasopressin and blood pressures demonstrated oestrous cycle variability. The mean (SEM) colonic balloon pressure triggering visceromotor responses was significantly higher in males (64 (4) mm Hg) than females (41 (1) mm Hg), P=0.002 and within females, proestrus rats had the lowest thresholds, (29 (1) mm Hg, P<0.01). Post-stimulation, vasopressin concentrations increased significantly in all groups (males 1.34 (0.39) to 2.24 (0.74) pmol litre(-1); females 1.54 (0.24) to 2.88 (0.58) pmol litre(-1); P=0.002). Within groups statistically significant differences were measured in proestrus 2.06 (0.56) to 3.42 (1.12) and oestrus 1.16 (0.38) to 2.76 (0.60) pmol litre(-1) (P<0.05). High vasopressin concentrations coupled with low-pressure stimulation during proestrus shows sex-hormone dependent integration of the neuroendocrine response to noxious visceral stimulation.

Analysis of Variance↗
PubMed2000

Urgency of caesarean section: a new classification.

A new classification for caesarean section was developed in a two-part study conducted at six hospitals. Initially, 90 anaesthetists and obstetricians graded ten clinical scenarios according to five different classification methods--visual analogue scale; suitable anaesthetic technique; maximum time to delivery; clinical definitions; and a 1-5 rating scale. Clinical definitions was the most consistent and useful, and this method was then applied prospectively to 407 caesarean sections at the same six hospitals. There was close agreement (86%) between anaesthetists and obstetricians for the five-point scale (weighted kappa 0.89), increasing to 90% if two categories were combined (weighted kappa 0.91). We suggest that the resultant four-grade classification system--(i) immediate threat to life of woman or fetus; (ii) maternal or fetal compromise which is not immediately life-threatening; (iii) needing early delivery but no maternal or fetal compromise; (iv) at a time to suit the patient and maternity team--should be adopted by multidisciplinary groups with an interest in maternity data collection.

Anesthesia, Obstetrical↗
PubMed2000

Future pain drugs. 8-9 March 2000, London, UK.

Closing the gaps between product design and delivery of analgesic drugs, and individual patient needs for pain relief was the focus for this meeting. The changes in theories of nociceptive activity, from a mechanistic to a biopsychosocial disorder with diverse systemic modulation, were highlighted by Mark Travers (Janssen-Cilag, Titusville, NJ, USA), including examples from clinical trials where a patient's expectations were not met and high drop-out rates occurred. The need to target drug design and delivery to defined patient groups was clearly an important issue. The potential for drug delivery systems, such as polymer matrix and transmucosal applications, was discussed. Analogs of naturally occurring compounds that interact with nociceptive systems are creating opportunities for novel antinociceptive and anti-hyperalgesic peptides. The never-ending discovery of new pain transmission and transduction mechanisms fuels the potential for synthesis of more compounds. In reality, the multifactorial nature of pain, with its large potential commercial market in hospitals and within the community, demands a similar multidimensional approach to pain therapies. Much of the emerging preclinical data suggest that interactions between the processes of nociception and the modulatory, inhibitory, immune and inflammatory systems that may generate or maintain nociceptive activity, may be important for the future development of therapeutics in pain management. Such data are being generated through studies with, for example: the tripeptides, vanilloid, galanin and neuropeptide Y receptor ligands; the pharmacological effects of sumatriptan (Glaxo Wellcome plc); and, the serotonin and norepinephrine selective antidepressant, venlafaxine (Effexor XR; Wyeth-Ayerst International Inc).

Journal Article↗
PubMed1999

Towards effective obstetric anaesthetic audit in the UK.

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 professional standards to be defined and tested so that high quality obstetric anaesthetic care can be maintained.

Journal Article↗