title: A randomised controlled trial of the effect of a head-elevation pillow on intrathecal local anaesthetic spread in caesarean section.
abstract: BACKGROUND
  A head-elevation pillow places a patient in a ramped posture, which maximises the view of the larynx during laryngoscopy, particularly in obese parturients. In our institution an elevation pillow is used pre-emptively for neuraxial anaesthesia. We hypothesised that head-elevation may impair cephalad spread of local anaesthetic before caesarean section resulting in a lower block or longer time to achieve a T6 level. We aimed to investigate the effect of head-elevation on spread of intrathecal local anaesthetics during anaesthesia for caesarean section.
  
  
  METHODS
  One-hundred parturients presenting for caesarean section under combined spinal-epidural anaesthesia were randomised to either the standard supine position with lateral displacement or in the supine position with lateral displacement on an head-elevation pillow. Each patient received intrathecal hyperbaric bupivacaine 11 mg, morphine 100 μg and fentanyl 15 μg. Patients were assessed for adequacy of sensory block (T6 or higher) at 10 min.
  
  
  RESULTS
  Sensory block to T6 was achieved within 10 min in 65.9% of parturients in the Elevation Pillow Group compared to 95.7% in the Control Group (P<0.05). Compared to the Control Group, patients in the Elevation Pillow Group had greater requirements for epidural supplementation (43.5% vs 2.1%, P<0.001) or conversion to general anaesthesia (9.3% vs 0%, P<0.04).
  
  
  CONCLUSIONS
  Use of a ramped position with an head-elevation pillow following injection of the intrathecal component of a combined spinal-epidural anaesthetic for scheduled caesarean section was associated with a significantly lower block height at 10min.
authors.affiliation: Department of Anaesthesia, National Maternity Hospital, Dublin, Ireland. Electronic address: asmak33@hotmail.com.
authors.forename: H
authors.initials: H
authors.lastname: Elfil
authors.affiliation: Department of Anaesthesia, National Maternity Hospital, Dublin, Ireland.
authors.forename: L
authors.initials: L
authors.lastname: Crowley
authors.affiliation: School of Public Health, Physiotherapy and Population Science, University College Dublin, Dublin, Ireland.
authors.forename: R
authors.initials: R
authors.lastname: Segurado
authors.affiliation: Department of Anaesthesia, National Maternity Hospital, Dublin, Ireland.
authors.forename: A
authors.initials: A
authors.lastname: Spring
mesh_terms: D000328:Adult; D000701:Analgesics, Opioid; D000767:Anesthesia, Epidural; D000773:Anesthesia, Obstetrical; D000775:Anesthesia, Spinal; D000779:Anesthetics, Local; D001512:Bedding and Linens; D002045:Bupivacaine; D002585:Cesarean Section; D005260:Female; D005283:Fentanyl; D006257:Head; D006801:Humans; D009020:Morphine; D056888:Patient Positioning / Q000379:methods*; D011247:Pregnancy
chemical_list: D000701:Analgesics, Opioid; D000779:Anesthetics, Local; D009020:Morphine; D005283:Fentanyl; D002045:Bupivacaine
keywords: Caesarean section; Combined spinal-epidural anaesthesia; Head elevation pillow