Effect of co-administration of different doses of phenylephrine with oxytocin on the prevention of oxytocin-induced hypotension in caesarean section under spinal anaesthesia: A randomised comparative study

Dural sac cross-sectional area measured using ultrasound to modify the dosage of local anaesthetic in spinal anaesthesia for transurethral resection of prostate surgery: A prospective, double blind, randomised controlled study

BACKGROUND AND AIMS

The area of lumbar spinal canal decreases with age, and hence the level of sensory blockade is higher in the elderly after spinal injection. The present study optimised the dose of local anaesthetic in elderly patients based on the lumbar dural sac cross sectional area (DSCSA) determined using ultrasound.

METHODS

Sixty patients of age above 60 years undergoing transurethral resection of prostrate (TURP) surgery in a tertiary care hospital were included in the study. Patients were categorised into two groups of 30 each based on a computer-generated random number table. In the control group (C), 2 ml of 0.5% hyperbaric bupivacaine was given and in the ultrasound group (U), the drug dose was modified according to DSCSA which was measured using the formula area = p (diameter/2) ².

RESULTS

The DSCSA and bupivacaine dosage were significantly lower in group U compared to control group (P = 0.0001). The maximal level of cephalad spread of sensory blockade was significantly lower in ultrasound group, than in control group (P = 0.002). The two-segment block regression time and motor recovery time was less in group U. Higher mean arterial pressure (105.8 ± 9.66 mmHg; P = 0.007), and a lower decrease from baseline (14.15 ± 7.55%; P = 0.041) was noted in group U after subarachnoid block.

CONCLUSION

The estimation of DSCSA is an effective parameter and can be used to modify the dose of local anaesthetic for subarachnoid block in elderly patients undergoing TURP surgery.

A randomised double-blind trial of minimal bolus doses of oxytocin for elective caesarean section under spinal anaesthesia: Optimal or not?

Background

Oxytocin administration regimens are arbitrary and highly subjective. Hence, it is essential to reinvestigate the appropriate dose for effective uterine contraction with minimal bleeding and adverse effects.

Aim

To determine the optimal dose of bolus oxytocin for uterine contractions for elective caesarean section under spinal anaesthesia.

Methods

Ninety term mothers (37 to 41 weeks) undergoing caesarean section electively under spinal anaesthesia were considered for the trial and divided into three groups to receive oxytocin bolus of one, two or three units. The uterine tone was assessed at 2 min after oxytocin administration. Intraoperative blood loss, mean arterial pressure, heart rate and possible side effects were also compared. Paired t-test, Kruskal-Wallis test, Chi-square test and analysis of variance (ANOVA) test with Scheffe multiple comparisons were used as inferential statistics.

Results

Adequate uterine contraction was seen in 66% of participants who received one unit of oxytocin, and in 83.3% of participants who received two units of oxytocin. All those who received three units of oxytocin had an adequate uterine contraction. Blood loss was inversely related to the bolus dose of oxytocin.

Conclusions

Lower bolus oxytocin doses of one and two units were inadequate for uterine contraction at elective caeserean section, while three units appeared to be effective in terms of adequate uterine contraction, reduced blood loss and stable haemodynamic system and absent side effects.