PubMed Health⌕ Search

Biomedical subjects

P D W Fettes

Publications and source records attributed to P D W Fettes.

4 recordsLinked to original sources
PubMed2006

Intermittent vs continuous administration of epidural ropivacaine with fentanyl for analgesia during labour.

BACKGROUND: Many years ago regular intermittent bolus administration of epidural local anaesthetic solution was recognized to produce more effective analgesia than continuous infusion, but only recently has the development of suitable pumps allowed the former technique's wider evaluation. METHODS: In this randomized, double-blind trial, 40 primigravid patients had a lumbar epidural catheter inserted, and plain ropivacaine 0.2% 15-20 ml was titrated until analgesia and bilateral sensory block to T10 were produced (time zero). Patients were then given either an infusion of ropivacaine 2 mg ml(-1) with fentanyl 2 microg ml(-1) at 10 ml h(-1), or hourly boluses of 10 ml of the same solution. Pain, sensory block and motor block were measured frequently. If requested, additional 10 ml boluses of the study mixture were given for analgesia. RESULTS: There were no differences between the two groups in patient characteristics, obstetric/neonatal outcome, or in sensory or motor block. A total of 12 (60%) patients in the continuous group required one or more additional boluses compared with 4 (20%) patients in the intermittent group (95% CI 9.6-61.7%, P=0.02). Therefore the intermittent group received a lower total drug dose than the infusion group (P=0.02). Duration of uninterrupted analgesia (time to first rescue bolus) was longer in the intermittent group (P<0.02). CONCLUSIONS: The intermittent group required fewer supplementary injections and less drug to maintain similar pain scores, sensory and motor block compared with the continuous group. This represents a more efficacious mode of analgesia.

Adult↗
PubMed2006

Effect of spinal flexion on the conus medullaris: a case series using magnetic resonance imaging.

Anatomy textbooks state that the conus medullaris moves cephalad when the vertebral column is flexed. This could confer protection against spinal cord damage during dural puncture, but has not been demonstrated in vivo. We therefore imaged the spine of 10 volunteers using magnetic resonance imaging to determine if such movement occurs with the spine in the neutral and flexed positions. The position of the conus medullaris in relation to the superior endplate of the L1 vertebra was determined. On spinal flexion, the conus medullaris moved cephalad in three subjects and caudad in three subjects, with no change in the remaining four. The median overall movement (95% CI [range]) was 0 mm (4 mm caudad to 1 mm cephalad [3 mm caudad to 1 mm cephalad]; p = 1.0). Whilst spinal flexion may facilitate needle insertion during dural puncture, it is unlikely to confer extra protection against spinal cord damage.

Adult↗
PubMed2004

Comparison of plain and hyperbaric solutions of ropivacaine for spinal anaesthesia.

BACKGROUND: Preliminary work has shown that ropivacaine provides spinal anaesthesia of shorter duration than bupivacaine, and may be of particular use in the day-case setting. However, there are few data comparing the actions of plain and hyperbaric solutions of this drug. METHODS: Forty ASA grade I-II patients undergoing elective perineal surgery under spinal anaesthesia were randomized to receive 3 ml ropivacaine 5 mg ml(-1), either in plain solution or with glucose 50 mg ml(-1). The extent and duration of sensory and motor block, pulse rate, blood pressure, and time to mobilization were recorded. RESULTS: Two patients (one per group) were withdrawn because of total block failure. There were significant differences in median time to onset of sensory block at T10 (plain 10 min; hyperbaric 5 min; P<0.01), median maximum extent (plain T8; hyperbaric T4; P<0.05), and median duration of sensory block at T10 (plain 25 min; hyperbaric 115 min; P<0.001). However, median times to complete regression of both sensory (270 vs 240 min; P<0.05) and motor (180 vs 120 min; P<0.001) block were longer in the plain group. Patients therefore mobilized sooner in the hyperbaric group (218 [n=16] vs 286 min [n=17]; P<0.01). All the hyperbaric blocks were adequate for surgery, but three patients receiving plain ropivacaine required general anaesthesia. CONCLUSION: Addition of glucose 50 mg ml(-1) to ropivacaine 5 mg ml(-1) increases the speed of onset, block reliability, duration of useful block for perineal surgery, and speed of recovery. Plain solutions are less reliable for surgery above a dermatomal level of L1.

Adult↗