Background and Goal of Study: Suxamethonium is a depolarizing neuromuscular blocker, this has a fast onset of action and a short action. Rocuronium is a nondepolarizing neuromuscular blocker with a short latency time, and rapid development of the blockade. Length of action is proportional for the administered dose, 0.3 mg/ kg achieve a maximum neuromuscular blockade after 3 to 4 min, with a duration around 22 min.
This study aims to evaluate the quality of relaxation both for intubation and for maintenance using suxamethonium or rocuronium in patients undergoing laryngeal microsurgery.
Materials and Methods: Study with 30 patients, ASA I-II,scheduled for laryngeal microsurgery at the University Hospital Miguel Servet in Zaragoza, which was administered during the induction suxamethonium (1mg / kg) or rocuronium (0.3 mg / kg).
After standard monitoring we used neuromuscular monitoring (TOF) and after the induction was used rocuronium (0.3mg/kg) or suxamethonium (1mg/kg), according to the group. Intubation was made after assessment of a TOF with 0 responses. Measurements were made at 30, 60, 90, 120, 150, 180, 210 and 240 seconds, after neuromuscular blocker administration.
After right intubation, time of surgery was recorded and before extubation were reassessed the TOF: a T4/T1 ratio> 0.8 was considered optimal for extubation.
The analysis was performed using the statistical program Epi Info 3.2.2, Windows Word and Microsoft Excel.
Results and Discussion: We evaluated 30 patients in two groups: A (suxamethonium) B (rocuronium), 15 patients in each group. The average age for group A was 59 years and for B 63 years. The optimal condition for faster intubation was obtained in a patient of group A (30seconds), while 60% of the members of group B was intubated without difficulty at 180seconds after of rocuronium.
Only in the group which received suxamethonium had fasciculations, showing them in 87% of cases (13 patients).
The procedure had a mean duration of 18 and 22 min (A/B) respectively. No case need additional dose of neuromuscular relaxants, and finished the surgery, all patients in both groups were extubated without incidences, presenting a TOF T4/T1> 0.8.
Conclusion(s): Dose of 0.3 mg / kg allows optimal intubation conditions at 180 seconds after its administration with a short duration, allowing its use in short duration surgery, avoiding the use of depolarizing muscle blockers and adverse effects they carry with them.