Diabetes mellitus does not affect the neuromuscular blocking action of atracurium in dogs

To compare the duration of action of atracurium in diabetic and nondiabetic dogs.

Prospective, blinded, clinical study.

A total of 26 diabetic and 29 nondiabetic dogs.

Following preanaesthetic medication and intravenous (IV) propofol induction, anaesthesia was maintained with isoflurane in oxygen. Atracurium 0.2 mg kg^-1 IV was administered to provide neuromuscular blockade (NMB) and the responses (twitches; T) to train-of-four nerve stimulation were recorded by palpation and electromyography (EMG). Time to onset of NMB (from atracurium administration to loss of T4 by EMG), duration of NMB (to return of T1 by EMG) and also times to loss and return of T2-T4 were recorded. Heart rate (HR), mean arterial pressure, end-tidal isoflurane (Fe'Iso), end-tidal CO₂ concentrations and oesophageal temperature were recorded at onset of NMB and when T1_EMG returned. Groups were compared using t tests and Mann-Whitney U tests (p<0.05).

Diabetic dogs were older (9.9±0.3 compared with 6.8±0.7 years, p=0.0003). Group parameters were similar at onset and offset of NMB apart from HR at offset, which was higher for diabetics compared to nondiabetics (114±4 compared with 100±3 beats minute^-1, respectively, p=0.004), Fe'Iso was higher in the diabetic group at onset (1.3±0.03% compared with 1.2±0.04%, p=0.026) and offset (1.4±0.03% compared with 1.3±0.03%, p=0.007), and temperature was higher for diabetics at onset (37.5±0.1 °C compared with 37.0±0.2 °C, p=0.012) and offset (37.5±0.1 °C compared with 36.9±0.2 °C, p=0.004). The duration of action of atracurium_(tactile) and atracurium_(EMG) were similar for both groups_. CONCLUSIONS AND CLINICAL RELEVANCE: The duration of action of atracurium was similar in diabetic and nondiabetic dogs as indicated by tactile and EMG monitoring.