Background: Arterial hypotension is frequent in patients undergoing anesthesia and may aggravate the outcome. Common genetic variations may influence the cardiovascular response to anesthesia. In this retrospective cohort study, we tested whether variation in the gene encoding the β2-adrenergic receptor (ADRB2) influences perioperative arterial blood pressure and consequently the use of vasopressors.
Methods: Five hundred seventy-one Danish Caucasians undergoing neurosurgery were genotyped for 5 marker single-nucleotide polymorphisms (SNPs) within ADRB2 (Gly16Arg, Gln27Glu, Thr164Ile, Arg175Arg, and Gly351Gly). A pairwise tagging principle was used to identify ADRB2 haplotypes. Mean arterial blood pressure (MAP) was recorded in the supine awake state and, together with administration of vasopressors (ephedrine and/or phenylephrine), for 30 minutes after induction of general anesthesia (sevoflurane/remifentanil or propofol/remifentanil).
Results: Four hundred thirteen (72%) patients received ephedrine and/or phenylephrine. Only baseline MAP (P < 0.001) and the Arg175Arg SNP (P = 0.01) were associated with nadir perioperative MAP. The Gly16Arg SNP but no other SNPs showed a trend toward an association with the amount of vasopressors used during anesthesia with Arg16 homozygotes receiving less ephedrine equivalents. The Arg16-Gln27-Thr164-Arg175-Gly351 haplotype was associated with approximately 13% lower vasopressor requirements than the most common Gly16-Glu27-Thr164-Arg175-Gly351 haplotype (P = 0.01).
Conclusions: Gly16 carriers received larger amounts of vasopressor compared with Arg16 homozygotes. This corresponds to previous studies demonstrating that the Gly16 allele in ADRB2 is associated with vasodilation and high cardiac output.