Comparison of clinical assesment and the use of peripheral nerve stimulator with a new criteria for ecaluation of patient safety from neuromuscular blockage.

Abstract

Background : Muscle relaxants currently play important role as general anesthesia. However their residues after treatment could cause diverse effect and danger the patients. At Prapokklao Hospital most evaluations on the recovery from muscle relaxants have been done by observation of clinical symptoms. The other way has been operated by using peripheral nerve stimulator (PNS) which could provide higher precision.Unfortunately the number of PNS has some limits. In the past the safety level from these muscle relaxants have to be observed from TOF ratio ≥ 0.7. Recently the safety level have been adjusted to TOF ratio ≥ 0.9 which there have no reported studies involving this new criteria compared with clinical evaluations.

Objective : 1) To study the effective recovery from muscle relaxant residues after operation by using PNS with the new safety criteria TOF ≥ 0.9.
2) The relationship between the clinical evaluations and new PNS criteria with corresponding to type of non-depolarizing muscle relaxant (NDMR).

Method : Prospective unblind clinical controlled trials have been explored in the patients undergoing operation as elective case at Prapokklao Hospital. ASA status 1-2 had obtained general anesthesia coupled with non-depolarizing muscle relaxants and then got reversal drug at the end operation. At recovery rooms the TOF ratio and clinical evaluations have been detected. The new safety criteria TOF ≥ 0.9 has been applied to the whole study.

Results : It was found that the residual effects of muscle relaxants have been detected at immediate measurement in recovery rooms for 75 percent out off the studied patients. The patients getting pancuronium showed the highest diverse effect (93.33 percent) and need time about 14.33 min for taking a rest to reach the safety level (TOF ratio > 0.9). For clinical evaluations it was found that raising head up over 5 minutes and having strong coughing had significant correlations with TOF ratio ≥ 0.9 (P < 0.05). For the rest of symptom evaluations they had no significant relationships.

Conclusion : Using PNS technique with the new TOF ratio resulted in larger positive detected measurements compared to the old TOF criteria. Therefore in case of need we have to select appropriate duration of action of NDMR and give the optimum doses to those patients. For some special patients using PNS technique coupled with clinical evaluations may be necessary.

Key wards : residual curarization TOF ratio