Background: Diabetes mellitus causes motor nerve dysfunction and degeneration that may alter the response to neuromuscular blocking drugs.
Objective: To analyse the risk of residual neuromuscular block (RNMB) induced by rocuronium given in standard doses to patients with type 2 diabetes mellitus (T2DM).
Design: A prospective, observational study.
Settings: Hospital San Jorge, Huesca and Hospital San Pedro, Logroño, Spain, from December 2011 to June 2012.
Patients: T2DM patients with no diabetic neuropathy or neurological symptoms (n = 32) and healthy controls (n = 39).
Intervention: All participants received a single dose of rocuronium 0.6 mg kg. Neuromuscular block was monitored throughout surgery until a train of four (TOF) ratio of at least 0.9 was achieved.
Main outcome: Time from rocuronium injection to a TOF ratio of at least 0.9 (DURTOF90).
Secondary outcomes: Time to reappearance of T1, T2, T3 and T4 of TOF; glycosylated haemoglobin values (HbA1c); correlation between blood glucose control and DURTOF90 in the group of diabetic patients.
Results: No significant differences in age, weight, renal function or other characteristics interfering with neuromuscular block were seen between T2DM patients and controls. DURTOF90 was significantly longer in the group of T2DM patients than in the controls (109.86 vs. 84.77 min, P = 0.001). Times to reappearance of T1, T2, T3 and T4 of TOF were also significantly longer in the T2DM group. No correlation was found between HbA1C and DURTOF90 values. In addition, DURTOF90 did not appear to be related to elevated blood glucose levels.
Conclusion: Diabetic patients, even in the absence of complications, have an increased risk of RNMB after rocuronium administration compared with those without diabetes. Poorer glycaemic control of diabetes does not appear to increase the risk. Appropriate dose and vigilant monitoring of the neuromuscular blocker is helpful in patients with T2DM.