Plasma Gabapentin Concentration During and Following Cardiac Bypass

Queen's University16 enrolled

Overview

This open label investigation is to determine whether cardiopulmonary bypass affects plasma gabapentin concentration after preoperative administration in the setting of cardiac bypass surgery. Following signed informed consent, 16 patients scheduled for cardiac bypass surgery will be given gabapentin (600mg, oral) 1 hour prior to surgery, 1 hour following extubation and then every 8 hours for a total of 4 doses. Plasma gabapentin levels will be measured prior to induction, prior to bypass, 10 min into the bypass procedure, 10 minutes before separation from bypass, 30 minutes following bypass and then before and 2 hours following each of the next 3 doses of gabapentin. Pain scores, sedation scores, side effects and morphine equivalents will be documented for one day following surgery.

Study Type

INTERVENTIONAL

Allocation

Purpose

TREATMENT

Masking

NONE

Enrollment

Conditions

Cardiopulmonary Bypass

Interventions

Eligibility

Sex: ALLMin age: 18 Years

Medical Language ↔ Plain English

Inclusion Criteria: * scheduled for cardiac bypass surgery involving median sternotomy and CPB * signed informed consent Exclusion Criteria: * history of chronic pain * regular opioid consumption * regular anticonvulsant consumption * regular gabapentin or pregabalin use * recent congestive heart failure * ejection fraction \<35% * chronic pulmonary disease * liver disease * renal insufficiency (preoperative creatinine \> 140umol/L * history of adverse reaction to acetaminophen

Outcomes

Primary Outcomes

plasma concentrations of gabapentin

Time frame: 1 hour before surgery, 10 min following initiation of bypass, 10 min before separation from bypass, 30 min following bypass, and then before and 2 hours following each of the next 3 doses of gabapentin