This study aimed to evaluate the effect of Neostigmine partial dose towards neuromuscular blockade of rocuronium

Approval from Ethical Committee of Faculty of Medicine University of Indonesia was acquired prior conducting the study. Subjects were given informed consent before enrolling the study and randomized into two groups. Intravenous (IV) cannula with Ringer Lactate fluid, non-invasive blood pressure monitor, electrocardiogram (ECG) and pulse-oxymetry were set on the subjects in the operation room. After preoxygenation was given with 100% oxygen, general anesthesia induction was done with midazolam 0.01-0.02 mg/kg, fentanyl 3 mcg/kg, propofol 1-2 mg/kg, and rocuronium 0.6 mg/kg. Following induction, endotracheal intubation or laryngeal mask insertion was performed. Maintenance was done by sevoflurane 1.2 vol%, and fentanyl 1.2 mcg/kg. After the surgery had finished, fentanyl drip was stopped. Subjects were then observed until spontaneous breaths occured adequately (tidal volume ≥ 5 ml/kg) before train of four (TOF) ratio was evaluated using acceleromyography (AMG). Before reversal (neostigmine) was given, anesthetic gas was stopped and duration of operation as well as post-operative TOF ratio was recorded. The time since reversal was given then recorded. Group A received neostigmine partial dose (0.02 mg) in combination with atropine 0.4 mg for every milligram of neostigmine. Group B received TOF ratio-based dose of neostigmine in combination with atropine 0.4 mg for every milligram of neostigmine. After administration of neostigmine, TOF ratio was measured every 5 minutes until TOF ratio of ≥ 90% was achieved, and finally definitive airway could be removed. For Group A, another partial dose of neostigmine was given after 10 minutes from the first reversal dose if the TOF ratio of ≥90% had not been reached. For Group B, another TOF ratio-based dose of neostigmine was given after 10 minutes from the first reversal dose if the TOF ratio of ≥90% had not been reached. Subjects were then transported to recovery room. Data was analyzed using Statistical Package for the Social Sciences (SPSS), for numerical data using unpaired T-test or Mann-Whitney-U test, for categorical data using Chi-square test or Fischer Exact's Test. Data normality was tested by Kolmogorov-Smirnov test. Significant value is p<0.05.

Inclusion Criteria:

• patients aged 18-60 years old
• American Society of Anesthesiologists (ASA) physical status I-II who were planned to undergo any elective surgery at operating room in general anesthesia
• subjects had been explained about the study, and agreed to enroll and have signed the informed consent form

Exclusion Criteria:

• BMI ≥ 30
• had any severe kidney or liver disease
• had neuromuscular disease or asthma

Drop out Criteria:

• Duration of operation less than one hour or more than 2 hours
• during surgery received maintenance dose of neuromuscular block
• intraoperative cardiac arrest was occurred