Assessment of gastric emptying of maltodextrin, coffee with milk and orange juice during labour at term using point of care ultrasound: a non-inferiority randomised clinical trial.

Labouring women have been shown to have slower gastric emptying than non-pregnant subjects, and this argument is sometimes used to recommend fasting guidelines such as nil-by-mouth during labour. We performed a parallel group, randomised non-inferiority trial, comparing gastric emptying of 450 ml isocalorically-adjusted maltodextrin, coffee with milk or pulp-free orange juice, with 18 women in each group. The women were initially fasted for 2 h for clear fluids, 6 h for a light meal and 8 h for a high fat or high protein meal. We performed gastric ultrasound in the semirecumbent-right lateral decubitus position. Gastric antral area was measured at baseline and at 5 min, 30 min, 60 min, 90 min and 120 min. Gastric emptying of maltodextrin was significantly faster than coffee with milk (p < 0.001) and orange juice (p < 0.001). There was no statistically significant difference between pulp-free orange juice and coffee with milk (p = 0.97). The estimated gastric residual volume was lower than baseline from 90 min after drinking maltodextrin. In labouring women, maltodextrin is cleared from the stomach faster than coffee with milk and orange juice. Gastric emptying depends on other factors besides the caloric load and volume of the drink.

The effect of beta-2 adrenergic receptor haplotype variations on the haemodynamic response following spinal anaesthesia for caesarean delivery.

We investigated whether genetic variations of the beta-2 adrenergic receptor (ADRB2) modulate the haemodynamic response following spinal anaesthesia for caesarean delivery. We focused on the effects of haplotypes formed by combinations of the Arg16Gly and Gln27Glu polymorphisms. Clinical data from 143 healthy parturients were collected. Only the ArgGln haplotype appeared to influence the risk of hypotension, most probably through a recessive mode of inheritance (p=0.027). Therefore, patients were grouped according to ArgGln homozygosity in two groups: presence of one or no copies of the haplotype (n=120) or two copies of the haplotype (n=23). Both groups presented similar baseline characteristics. Comparatively, patients homozygous for the ArgGln haplotype presented consistently higher blood pressure levels throughout the evaluation period (p=0.001 for systolic arterial pressure variation from baseline). In conclusion, our results demonstrate that haplotype variations of the the ADRB2 modulate the haemodynamic response following spinal anaesthesia for caesarean delivery.