Does the addition of active body warming to in-line intravenous fluid warming prevent maternal hypothermia during elective caesarean section? A randomised controlled trial.

INTRODUCTION: Inadvertent perioperative hypothermia occurs frequently during elective caesarean section but perioperative active body warming is not widely used. There is a paucity of evidence of its use in the obstetric population, and no applicable guidelines. We set out to identify a superior active warming method for preventing inadvertent perioperative hypothermia. METHODS: Following ethical approval, 132 women presenting for uncomplicated elective caesarean section under spinal anaesthesia were recruited. All participants received in-line intravenous fluid warming and were randomised to one of three parallel groups: no active body warming; forced air warming; and conduction mattress warming. The primary outcome was the difference in mean core temperature, measured on admission to the recovery room, between study groups. Core temperature and thermal comfort were measured perioperatively at 15-min intervals. Estimated blood loss, haemoglobin change, length of hospital stay and neonatal core temperature were also recorded. RESULTS: One-hundred-and-thirty-one women completed the study. There was no significant difference in mean core temperature on admission to the recovery room (36.6°C vs. 36.6°C vs. 36.6°C, η2=0.005, P=0.74). Maternal hypothermia was prevented in all groups with only 0.3% hypothermic at any of the temperature measurements (3/1016). There was no difference in mean neonatal core temperature (36.3°C vs. 36.3°C vs. 36.3°C, η2=0.003, P=0.82); however, 59.4% (76/128) of all neonates were hypothermic. CONCLUSION: In-line intravenous fluid warming is sufficient to prevent maternal hypothermia and maintain core temperature. The addition of active body warming conferred no added benefit.

Introduction of enhanced recovery for elective caesarean section enabling next day discharge: a tertiary centre experience.

BACKGROUND: The widespread adoption of enhanced recovery programmes in various surgical specialties has resulted in patient benefits including reduced morbidity, reduced length of stay and an earlier return to normal activities. This evidence, along with the increased financial pressures in the UK National Health Service, has led many units to consider introducing such a programme for obstetric surgery. We report our experience in setting up an enhanced recovery programme for women undergoing elective caesarean section and a prospective analysis of factors that influence length of stay. METHODS: An enhanced recovery pathway was designed by a multidisciplinary team and introduced in March 2012. Factors influencing length of stay were determined using a log normal model. RESULTS: The proportion of women discharged on Day 1 increased from 1.6% in the first quarter of 2012 to 25.2% in the first quarter of 2014. The 30-day readmission rate was 4.4% for those discharged on Day 1 and 5.6% for Day 2. Earlier gestation, multiple birth, intention to breast feed, longer surgery and more time in the post-anaesthesia recovery unit were all independently associated with a longer postoperative stay. Women presenting for obstetric surgery with the indication "one previous caesarean section" were more likely to leave hospital earlier compared to most other indications. CONCLUSION: An enhanced recovery programme was successfully introduced into our unit. Many of the interventions were straightforward and could be adopted easily elsewhere.

Enhanced recovery from obstetric surgery: a U.K. survey of practice.

BACKGROUND: In the UK earlier discharge of patients following elective caesarean section would require that more patients are discharged the day after surgery. The introduction of enhanced recovery in other specialties has resulted in shorter postoperative stay. We surveyed current U.K. practice to find whether this was consistent with enhanced recovery and what changes units would need to introduce to establish such a programme. METHODS: We conducted an Obstetric Anaesthetists' Association approved electronic survey of all the U.K. lead obstetric anaesthetists between March and May 2013. RESULTS: A response rate of 81% was achieved with 96% of those who responded supporting the concept of enhanced recovery. Only 4% of units routinely discharged their patients on day one. There were a number of practices consistent with enhanced recovery. Postoperative pain was controlled by regular paracetamol (97%) and non-steroidal anti-inflammatory drugs (100% when not contraindicated), with oral opioids (68%) being used for breakthrough pain. Over 70% of units allowed minimal interruption of perioperative oral intake and 72% of units mobilised their patients within 12h of surgery or when the neuraxial block had worn off. In contrast, a minority of units monitored patient temperature in theatre (27%) or used active warming (18%), and 28% routinely removed the urinary catheter within 12h of surgery or when the neuraxial block had worn off. Regarding neonatal recovery, only 23% reported using delayed cord clamping and 53% used skin-to-skin contact in theatre. CONCLUSION: Most obstetric units support the concept of enhanced recovery following caesarean section and many could introduce a programme for elective surgery with relatively small changes in patient care.

Assessment of interdisciplinary communication for Category 1 caesarean sections.

We assessed how often the urgency of Category 1 caesarean sections was incorrectly recorded by the anaesthetic and theatre teams. Category 1 caesarean sections were identified over a 15-month period (September 2010 to November 2011), from the daily audit of emergency caesarean sections undertaken by the obstetric team. The categories of urgency as recorded by the attending anaesthetist and theatre team were noted for each case. There were 236 Category 1 caesarean sections identified, of which 47 were incorrectly recorded as Category 2 by either the anaesthetist alone (34), the theatre team alone (1) or both (12). Where the category of urgency was correctly recorded, 11.6% of cases had a decision-to-delivery interval of more than 30 min compared with 27.7% of cases recorded as Category 2 (p = 0.01, Fisher's exact test).

Use of the HemoCue near patient testing device to measure the concentration of haemoglobin in suction fluid at elective caesarean section.

We have investigated the suitability of the HemoCue photometer to measure the concentration of haemoglobin in suction fluid obtained at elective caesarean section in 30 women. Laboratory analysis was used as a gold standard against which values generated by the HemoCue were compared. We used the method of Bland and Altman to analyse the data. The bias and the limits of agreement were -0.013 and -0.39 to 0.36 mg x dl(-1) respectively, indicating a good level of agreement. Mean (SD) total blood loss calculated using these data, combined with the weight of the swabs, was consistently greater than clinical estimation: 768 (496) ml versus 506 (249) ml respectively (p < 0.001). We have found that the HemoCue near patient testing device may be used to estimate blood loss accurately in the suction fluid obtained at elective Caesarean section.

Dose response to intrathecal diamorphine for elective caesarean section and compliance with a national audit standard.

BACKGROUND: This double-blind randomised controlled trial investigated the most appropriate dose of intrathecal diamorphine to use with high-dose diclofenac as part of a multimodal analgesic regimen for caesarean section under subarachnoid block. We also wished to establish whether it was possible to satisfy the Royal College of Anaesthetists postoperative pain audit recommendation for this patient group. METHODS: One hundred and twenty patients presenting for elective caesarean section under subarachnoid block were recruited and divided into four groups. Treatment was standard except that patients were given either placebo or one of three different doses of intrathecal diamorphine (100 microg, 200 microg or 300 microg). All patients were given regular paracetamol, high-dose diclofenac and an hourly subcutaneous diamorphine regimen for breakthrough pain. RESULTS: There was a dose-dependent improvement in analgesia with intrathecal diamorphine. Only 37.9% of patients given 300 microg of intrathecal diamorphine had a visual analogue pain score of 3/10 or less throughout the study. There was a dose-dependent increase in the incidence of itching with intrathecal diamorphine although the incidence of nausea and vomiting was similar between groups. CONCLUSIONS: We found that for elective caesarean section under subarachnoid block with high dose diclofenac, analgesia was optimal with 300 microg of intrathecal diamorphine. Even the highest dose of intrathecal diamorphine did not achieve the Royal College of Anaesthetists postoperative audit target that 90% of patients should have a pain score of no more than 3/10. We believe that this target is too arduous.

Preoperative anxiety and postoperative satisfaction in women undergoing elective caesarean section.

BACKGROUND: The primary aim was to investigate whether preoperative anxiety in women undergoing elective caesarean section predicts postoperative maternal satisfaction with the process, perceptions of recovery, analgesic use or length of hospital stay. Other factors that might influence postoperative satisfaction were also explored. METHOD: In 85 women awaiting elective caesarean section, anxiety, social support and aspects of preparation were measured in the 24 hours preceding surgery. Maternal satisfaction and perceptions of recovery were assessed around the third postoperative day. Satisfaction with the preoperative information from the anaesthetist and postoperative pain relief were also measured at this time. Medical notes were used to gather information on analgesia use and length of hospital stay. RESULTS: Preoperative anxiety scores were comparable with those of general surgical/medical patients. Preoperative trait anxiety and state anxiety were inversely associated with postoperative maternal satisfaction. State anxiety was also inversely associated with better recovery. Preoperative anxiety was not associated with analgesic use or length of hospital stay. Linear regression analysis indicated the degree of satisfaction with information from the anaesthetist and perceived emotional support from the partner explained 52% of the variance in postoperative maternal satisfaction. CONCLUSION: Lower preoperative anxiety is associated with greater maternal satisfaction with elective caesarean section and better recovery. Information provided by anaesthetists and perceived emotional support are also of importance. It may be possible to identify women with high anxiety and facilitate satisfaction and recovery through providing additional supportive input.

Spontaneous intracranial hypotension--lessons to be learned for the investigation of post dural puncture headache.

We describe a case of spontaneous intracranial hypotension in a 36-year-old woman. This condition shares many of the features of post dural puncture headache, but without a dural puncture having been performed. The aetiology and management of this rare condition are discussed. We believe from experience within our own unit that most anaesthetists are unaware of spontaneous intracranial hypotension. Highlighting this condition is important, as anaesthetists are often involved in its management. In our case, radiological investigation involved the use of spiral computerised tomography to identify the site of the hole in the dura. Spiral computerised tomography is a relatively recent innovation, which may also be useful in the investigation of post dural puncture headache when the level of the puncture is unknown.

Comparison between alfentanil, pethidine and placebo in the treatment of post-anaesthetic shivering.

We have compared the effects of pethidine, alfentanil and placebo in the treatment of post-anaesthetic shivering. Ninety patients who shivered after routine surgery were allocated randomly to receive normal saline (n = 30), alfentanil 250 micrograms (n = 30) or pethidine 25 mg (n = 30). After 10 min, 26 patients had stopped shivering in the pethidine group which was significantly more than the incidence in the two other groups (placebo = 7; alfentanil = 12) (P < 0.0002). Alfentanil was not significantly different from normal saline in affecting shivering. We conclude that alfentanil 250 micrograms was not effective in the treatment of post-anaesthetic shivering.

Analgesia after day case laparoscopic sterilisation. A comparison of tramadol with paracetamol/dextropropoxyphene and paracetamol/codeine combinations.

In a prospective, double-blind trial we compared the analgesic efficacy of tramadol during the first 24 h after day case laparoscopic sterilisation with two commonly prescribed combination analgesics. Seventy-five women were allocated randomly to receive oral paracetamol 325 mg/dextropropoxyphene hydrochloride 32.5 mg, tramadol 50 mg or paracetamol 500 mg/codeine phosphate 30 mg as required after a standardised anaesthetic technique. There were no significant differences in average or worst pain, sleep disturbance, mobility, number of tablets taken, satisfaction or preference for stronger analgesia (26.2% of all patients). The incidences of nausea and vomiting were comparable between groups. There was a trend towards a lower incidence of central nervous system side-effects (drowsiness, dizziness, headache) in the paracetamol/codeine group. Tramadol may be considered an alternative analgesic for day case surgery although analgesic regimens of greater efficacy are required for many patients. The relative incidence of side-effects for tramadol and other analgesics requires further evaluation.

The minimum effective doses of pethidine and doxapram in the treatment of post-anaesthetic shivering.

This study was designed to find the minimum effective doses of doxapram and pethidine to stop post-anaesthetic shivering. Two hundred and twenty healthy patients who shivered following routine surgery were allocated randomly to receive one of 10 doses of doxapram (0.18, 0.23, 0.29, 0.35, 0.41, 0.47, 0.7, 0.93, 1.17 and 1.4 mg.kg-1), one of five doses of pethidine (0.12, 0.18, 0.23, 0.29 and 0.35 mg.kg-1) or saline. Probit analysis demonstrated that the number of patients who stopped shivering with doxapram was independent of the amount of drug given in this dose range. The lowest dose of doxapram (0.18 mg.kg-1) was significantly more effective than placebo (p < 0.01). For pethidine there was a dose-dependent effect on shivering to a maximum of 95% of patients successfully treated with 0.35 mg.kg-1. We conclude that 0.35 mg.kg-1 of pethidine is the minimum dose required to treat post-anaesthetic shivering effectively. We also conclude that 0.18 mg.kg-1 of doxapram is as effective as 1.4 mg.kg-1 in the treatment of post-anaesthetic shivering. Further study is required to find the minimum effective dose of doxapram.

Lack of efficacy of intra-articular opioids for analgesia after day-case arthroscopy.

A randomised double-blind placebo-controlled trial was undertaken to assess the analgesic efficacy of intra-articular opioids following arthroscopy of the knee. At the completion of surgery, patients received an intra-articular injection of: morphine 1 mg, buprenorphine 30 micrograms or 0.9% saline. There were no differences in pain scores among groups for the first 24 h postoperatively. We have found no clinical evidence for a peripherally-mediated opioid analgesic effect.

The prevention of postoperative nausea and vomiting using a combination of ondansetron and droperidol.

We have studied the effect of combination antiemetic therapy (ondansetron and droperidol) with morphine delivered by patient-controlled analgesia following major gynaecological surgery. Sixty patients were randomly allocated to one of three treatment regimens; ondansetron alone (4 mg bolus and 0.13 mg.ml-1 in the morphine solution), droperidol alone (1.25 mg bolus and 0.05 mg.ml-1 in the morphine solution), or both drugs in combination. For the first 12 postoperative hours, patients receiving combination therapy experienced significantly less nausea than those receiving single antiemetic therapy (p < 0.001). There was no difference between the regimens from 12 to 18 h. We conclude that a combination of ondansetron and droperidol added to morphine in a patient-controlled analgesia system reduces postoperative nausea to a greater extent than treatment with either drug alone following major gynaecological surgery.

Alfentanil-mediated analgesia during propofol injection: no evidence for a peripheral action.

We have investigated if alfentanil acts via peripheral opioid receptors to relieve the pain which occurs on injection of propofol. Thirty seconds before induction of anaesthesia and immediately after a tourniquet at 50 mm Hg greater than systolic pressure was inflated on the upper arm, patients were given either placebo (n = 22), alfentanil 1 mg (n = 22) or lignocaine 40 mg (n = 22) via an i.v. cannula in the dorsum of the hand. Pain during injection of propofol was assessed using a three-point verbal rating scale, recorded at 8-s intervals. We found a significant reduction in pain after lignocaine compared with the two other groups (P < 0.001), but there was no difference between the placebo and alfentanil groups. We conclude that alfentanil does not relieve pain on injection with propofol via an action on peripheral opioid receptors when alfentanil is limited to the forearm for 30 s before induction of anaesthesia.

The effect of fetal calf serum on intracellular calcium in GH3 cells.

We have investigated the mechanism of action of fetal calf serum (FCS) on GH3 pituitary tumour cells by measuring intracellular free calcium levels. On the addition of FCS (1%) there was a transient increase in intracellular Ca2+ levels which was attenuated in conditions of reduced extracellular calcium concentrations. The Ca2+ response was abolished by the prior addition of lanthanum chloride (1mM). In contrast, the elevation of cytosolic calcium levels by TRH (100nM), an agonist which causes the mobilisation of calcium from the endoplasmic reticulum, was attenuated but not abolished by lanthanum chloride (1mM). We suggest that FCS (1%) causes the release of calcium from the plasma membrane and the influx of calcium from the extracellular milieu, but does not mobilise calcium from the endoplasmic reticulum.