Treatment of obstetric post-dural puncture headache. Part 2: epidural blood patch.

The 2009-12 MBRRACE-UK report highlighted the deaths of two women in whom dural puncture had occurred during insertion of a labour epidural catheter. Despite suffering long-term headaches, neither woman was adequately followed-up after discharge from hospital. Death resulted from a cerebral vein thrombosis in one case and a subdural haematoma in the other. Due to significant variation in the treatment of obstetric post-dural puncture headache, an Obstetric Anaesthetists' Association working group was set up to produce evidence-based guidelines to guide clinicians. These guidelines have been condensed into two review articles. In this second review, the role of an epidural blood patch is discussed using a question and answer format.

Treatment of obstetric post-dural puncture headache. Part 1: conservative and pharmacological management.

The 2009-12 MBRRACE-UK report highlighted the deaths of two women in whom dural puncture had occurred during insertion of a labour epidural catheter. One woman received an epidural blood patch, the other did not, but both suffered with chronic headaches following discharge from hospital. Neither woman was adequately followed-up. Death resulted from a cerebral vein thrombosis in one case and a subdural haematoma in the other. Surveys of clinical practice in the UK have revealed significant variation in anaesthetic practice in the management of obstetric post-dural puncture headache. To help provide guidance on treatment, the Obstetric Anaesthetists' Association set up a working group to review the literature and produce evidence-based guidelines for management of obstetric post-dural puncture headache. These guidelines have been condensed into two review articles, the first of which covers conservative and pharmacological treatment.

Choice of anaesthetic agents for caesarean section: a UK survey of current practice.

BACKGROUND: A national survey of current practice and preferred drug choices for both induction and maintenance of general anaesthesia for caesarean section was undertaken. METHODS: Following approval by the Obstetric Anaesthetists' Association, all UK consultant members were invited to respond to an electronic survey. RESULTS: The response rate was 56% (691/1228). Ninety-three percent of respondents use thiopental for induction: 58% (15% definitely and 44% probably) would support a change to propofol for induction. Thiopental was used in most cases for historical reasons (37%) or to reduce awareness (31%); other considerations included a clear end-point, dose predictability, cardiovascular stability, effects on the baby and drug licence concerns. Fifty-seven percent indicated that their trainees were encouraged to use thiopental for non-obstetric anaesthesia. Fifteen percent of respondents use opioids during rapid-sequence induction. Eighty-five percent use nitrous oxide; 53% of respondents use sevoflurane (51.6%) or desflurane (1.6%) for maintenance of anaesthesia, and this would increase to over 80% if financial constraints were removed. CONCLUSION: Our survey suggests that while thiopental remains the induction agent of choice in the UK, a reasonable body of medical opinion would support a change to propofol for induction. This is reassuring as thiopental becomes more difficult and expensive to obtain.

Rapid sequence spinal anaesthesia for category-1 urgency caesarean section: a case series.

SUMMARY: General anaesthesia is the fastest method for anaesthetising a category-1 caesarean section but is associated with increased maternal morbidity and mortality. We describe the 'rapid sequence spinal' to minimise anaesthetic time. This consists of a no-touch spinal technique, consideration of omission of the spinal opioid, limiting spinal attempts, allowing the start of surgery before full establishment of the spinal block, and being prepared for conversion to general anaesthesia if there are delays or problems. We present a case series of 25 rapid sequence spinal anaesthetics for category-1 caesarean section. The mean (SD [range]) decision-delivery interval was 23 (6 [14-41]) min. After excluding cases where there was an identified delay, the median (IQR [range]) time to prepare and perform the spinal was 2 (2-3 [1-7]) min, and time to develop a 'satisfactory' block was 4 (3-5 [2-7]) min. The total time to induce spinal anaesthesia was 8 (7-8 [6-8]) min. There were three pre-operative conversions to general anaesthesia and three women had pain during surgery that did not require treatment. Our data indicate that one might expect to establish anaesthesia in 6-8 min using a rapid sequence spinal. Careful case selection is crucial. While rapid anaesthesia is important, the reduction of the decision-delivery interval also requires attention to other stages in the pre-operative process.

Assessment of a modified four-category classification of urgency of caesarean section.

A four-category urgency classification for caesarean section (CS) based on clinical definitions was introduced in 2000. However, clinical application remains inconsistent. We proposed that modification of the wording of these definitions might improve consistency of assignment of urgency. A total of 349 maternity professionals applied an urgency category to 10 hypothetical cases of CS, using either the original or a modified classification. There was a supplementary question relating to urgency category in relation to the 30 minute decision-to-delivery time standard. The commonest urgency categories applied to the cases by the respondents were: Category 1: cord prolapse, significant placental abruption, maternal cardiorespiratory distress; Category 2: late fetal heart rate decelerations, CS pre-booked to avoid vaginal delivery but woman presents in advanced labour, bleeding placenta praevia without hypovolaemia, failed instrumental delivery with no fetal compromise; Category 3: deteriorating but compensated maternal medical condition; Category 4: operation at short notice but no clinical urgency. Consistency of responses in individual cases varied from 0.92 down to 0.55. Some 66% of respondents believe that only Category 1 cases should be included in a 30 minute decision-to-delivery time standard, whereas 34% would include Category 2 as well as Category 1 in this standard. The consistency of responses did not differ between the original and modified urgency classifications. Inter-rater reliability was better when comparing the answers from obstetricians compared with anaesthetists or midwives. This study found that the proposed modifications did not improve the consistency of application, and that any changes to the current classification should not be introduced without thorough investigation.

Spinal anaesthesia in a patient with hereditary spastic paraplegia: case report and literature review.

We report the use of spinal anaesthesia in a patient with hereditary spastic paraplegia who presented for manual removal of placenta following a normal vaginal delivery. This 18-year-old primigravida had been diagnosed with hereditary spastic paraplegia at 8 years of age when neurological examination revealed mild bilateral lower limb spasticity. A 25-gauge Whitacre spinal anaesthetic needle was inserted at the L3-4 intervertebral space and 0.5% plain bupivacaine 2 mL plus fentanyl 25 microg administered. The procedure was uneventful. At 24 hours postoperatively, there was full neurological recovery to pre-anaesthetic levels. The hereditary spastic paraplegias are a group of neurological disorders characterised by a slowly progressing spastic paraparesis. The neurological disorder and its anaesthetic implications are reviewed.

Where is T5? A survey of anaesthetists.

The extent of a regional block for Caesarean section must be tested and documented before surgery commences. In recent years a block to 'touch' that includes T5 has increasingly been considered the best predictive test for a pain-free Caesarean section. Our survey examines the consistency with which different anaesthetists identified the location of the T5 dermatome. Seventy-three anaesthetists were asked to mark a point on an anatomical picture to indicate where they would test for T5. Overall there was good agreement on the location of the T5 dermatome, but one in seven anaesthetists were inaccurate by two or more dermatomes. There were no statistically significant differences between the subgroups of senior house officer, specialist registrar and consultant anaesthetists. The knowledge of relevant dermatome levels should be an integral part of obstetric anaesthetic training.

Maternal cardiovascular consequences of positioning after spinal anaesthesia for Caesarean section: left 15 degree table tilt vs. left lateral.

Sixty healthy women undergoing elective Caesarean section were randomly allocated to either a measured 15 degrees left table tilt position (n = 31) or full left lateral position (n = 29) for a 15-min period after spinal blockade. Arm and leg blood pressure, ephedrine requirements, symptoms, fetal heart rate, cord gases and Apgar scores were recorded. Mean ephedrine requirements and incidence of hypotension were similar in the two groups. Arm systolic arterial pressure over time was similar in both groups, but leg systolic arterial pressure over time was significantly lower in the tilt group (p < 0.001); the mean leg systolic arterial pressure was lower for all 15 sequential recordings in the tilt group, reaching statistical significance (p < 0.05) at 4, 5, 6 and 8 min. Differences in maternal nausea, vomiting and bradycardia and fetal outcome were not statistically significant. Following spinal anaesthesia, even a true 15 degrees left table tilt position is associated with aortic compression.

Eating in labour. A randomised controlled trial assessing the risks and benefits.

The aim of this study was to determine whether permitting women in labour to eat a light diet would: (i) alter their metabolic profile, (ii) influence the outcome of labour, and (iii) increase residual gastric volume and consequent risk of pulmonary aspiration. Women were randomised to receive either a light diet (eating group, n = 48) or water only (starved group, n = 46) during labour. The light diet prevented the rise in plasma beta-hydroxybutyrate (p = 2.3 x 10(-5)) and nonesterified fatty acids (p = 9.3 x 10(-7)) seen in the starved group. Plasma glucose (p = 0.003) and insulin (p = 0.017) rose in the eating group but there was no difference in plasma lactate (p = 0.167) between the groups. There were no differences between the groups with respect to duration of first or second stage of labour, oxytocin requirements, mode of delivery, Apgar scores or umbilical artery and venous blood samples. Relative gastric volumes estimated by ultrasound measurement of gastric antral cross-sectional area were larger (p = 0.001) in the eating group. This was supported by the observation that those from this group who vomited, vomited significantly larger volumes than those in the starved group (p = 0.001). We conclude that eating in labour prevents the development of ketosis but significantly increases residual gastric volume.

Comparison of three different loading doses to establish epidural analgesia in labour.

Women requesting epidural analgesia were randomized to receive one of three loading doses. Group 1 received a single dose of bupivacaine 9.375 mg (15 ml of 0.0625%) containing fentanyl 37.5 microg and adrenaline 37.5 microg group 2 received a single dose of bupivacaine 15 mg (15 ml of 0.1%) containing fentanyl 30 microg and adrenaline 30 microg and group 3 received a test dose of bupivacaine 10 mg (4 ml of 0.25% - test) followed 5 min later by bupivacaine 20 mg (8 ml of 0.25% - loading). All groups received an infusion of bupivacaine 0.0625% with fentanyl 0.00025% and adrenaline 0.00025% at 10-12 ml/h started 15 min after the loading dose. Speed of onset of analgesia was the same in all three groups, with the majority of women achieving satisfactory analgesia by 20 min. Motor block was significantly increased in group 3 at 30 min, but by 1 h there was no difference in motor block between the groups.

Differential regulation of von Willebrand factor exocytosis and prostacyclin synthesis in electropermeabilized endothelial cell monolayers.

We have developed a system to permeabilize human umbilical vein endothelial cells in monolayer culture by application of a high-voltage electric field. The permeabilized preparation allows access of small molecules (M(r) < 1000) without loss of large cytosolic proteins. Electropermeabilized cells exocytose highly multimeric von Willebrand factor from secretory granules in response to added Ca2+ (EC50 = 0.8 +/- 0.02 microM), with levels comparable with those observed on stimulation of intact endothelial cells by physiological agonists. MgATP2- potentiates Ca(2+)-driven von Willebrand factor secretion. Other nucleoside triphosphates, but not non-hydrolysable analogues, can replace ATP. Electropermeabilized cells also synthesize and release prostacyclin in response to added Ca2+ (EC50 = 0.3 +/- 0.08 microM), but nucleoside triphosphates markedly inhibit, whereas nonhydrolysable GTP analogues increase, Ca(2+)-driven prostacyclin synthesis. We conclude that elevation of the intracellular [Ca2+] is sufficient to cause efficient exocytosis of von Willebrand factor from permeabilized cells, despite evidence that additional second messengers are needed in intact cells. We find no evidence in endothelial cells for a guanine nucleotide-binding protein promoting exocytosis, although one is clearly involved in stimulating Ca(2+)-driven prostacyclin synthesis.

Relationship Between the Systems Responsible for Uptake of 5-hydroxytryptamine and of Noradrenaline by Human Blood Platelets.

Human blood platelets carry a high affinity, but low capacity, saturable system for the uptake of noradrenalhe. The uptake is partially Na(+) dependent but cannot be categorised as uptake. It is distinct from the uptake system responsible for 5-hydroxytryptamine transport into the platelet since the selective inhibitors of the platelet uptake system for 5-hydroxytryptamine (citalopram, paroxetine) Wer from those for the uptake system for noradrenaline (normetanephrine, methylisoprenaline). 5-hydroxytryptamine inhibits noradrenaline uptake but with properties inconsistent with competition for the same uptake system while noradrenaline does not inhibit 5-hydroxytryptamine uptake. Neither noradrenaline nor 5-hydroxytryptamine uptake by human platelets is inhibited by dopamine.