To Study the Adequacy of Surgical Muscle Relaxation in Paediatric Patients Scheduled for Elective Groin Surgeries Under General Anesthesia using Sevoflurane without using Neuromuscular Blocking Agents

Introduction: In Anesthesia practice neuromuscular blocking agents (muscle relaxants) are used for intobation and surgical muscle relaxation. The use of modern inhalational anesthetics like sevoflurane is commonly practiced in paediatric anesthesia for induction and endotracheal intubation. LMA is alternative to endotracheal intubation. It is commonly used supraglotic device for the elective surgical procedures in adults and paediatric population. We conducted this study to see whether sevoflurane produces enough surgical muscle relaxation so that the use of neuromuscular blocking agents can be avoided. Patients and Methods: 84 paediatric patients of King Khalid Hospital (KSA) from April 2013 to February 2014 posted for elective surgical procedure were included in this observational study regarding the adequacy of surgical muscle relaxation. Induction of anesthesia Conflict of Interest: No Funding Source: No


Introduction
Muscle relaxants were introduced in anesthesia practice to facilitate the anesthetist for endotracheal intubations and for surgeons through operative site muscle

Original Article
relaxation. 1 Muscle relaxants prevent patient's movements during surgery.Their use avoid overdose of anesthetic drugs that is particularly risky in sick patients and commonly results in delayed recovery.
Use of LMA in anesthesia has revolutionized the practice of anesthesia for elective ambulatory and nonambulatory surgeries.Use of LMA has replaced the need of intubation. 2 Its use is safe and secure 3 .It can be used in adult and paediatric patients.Its use is comparable with face mask anesthesia for short procedures. 4voflurane is commonly used inhalational agent in modern paediatric anesthesia practice.It is safe and effective for the inhalational induction and maintenance of anesthesia. 5Sevoflurane produces enough muscle relaxation that is required for paediatric intubation. 6It produces rapid awakening and early recovery from anesthesia.
So we conducted this study to find out whether sevoflurane alone produces enough surgical muscle relaxation or not?

Patients and Methods
We conducted this study after getting institutional permission and patients consent from the parents or guardians.This observational study was conducted in King Khalid Hospital (KSA) from April 2013 to February 2014.

Inclusion Criteria
1. ASA 1 and 2 paediatric patients coming for elective groin surgeries.
2. All patients undergoing anesthesia by using LMA.

Exclusion Criteria
1. Patients having ASA status more than 2.
2. Patients coming for emergency surgeries.

Patients requiring muscle relaxants.
Base line reading of the blood pressure and heart rate was noted.Induction of anesthesia was done by using propofol 2 mg/kg and Fentanyl 2 mcg/kg.Maintenance of anesthesia was by using sevoflurane in oxygen and air.LMA was inserted to maintain the airway.Blood pressure and heart rate were kept within 20% of the baseline reading by titrating sevoflurane and intravenous fluids.
Primary variable was adequacy of surgical muscle relaxation.It was asked from surgeons during the procedures as follow; Good: Adequate surgical muscle relaxation.
Fair: Less adequate surgical muscle relaxation but no need of muscle relaxant.
Poor: Inadequate surgical muscle relaxation requiring muscle relaxant.
Other variable measured was recovery of the patients.It was noted as smooth or delay.
All the patients were shifted to the recovery room at the end of anesthesia and discharged today surgery unit or ward upon satisfactory recovery.
All the data (age, sex, type of surgery, adequacy of muscle relaxation and recovery status) was analyzed by using SPSS 16 to find out the outcomes.Numerical variables are represented in terms of mean and standard deviation.Qualitative variables are represented as frequencies and percentages.

Results
Mean age of the patients was 2.4 year.There were 76 male and 8 female patients.47 patients were operated for inguinal herniotomy, 32 for orchedopexy and 5 for umbilical herniotomy.Surgical relaxation was good in all of the patients and none of them required muscle relaxant.Recovery of all the patients was smooth.

Discussion
Our study showed that in paediatric groin surgeries, sevoflurane produced enough surgical muscle relaxation and there was no need of additional muscle relaxants.
Muscle relaxants were introduced in anesthesia practice in 1942. 7Alan Stead summarized the main advantages of muscle relaxants in paediatric anaesthesia as follows 8 : 1.They provide a means of effecting (tracheal intobation) and maintaining control of respiration throughout the operation.
2. The patient is completely relaxed and the work of the surgeon is facilitated.3. The quantity of toxic anaesthetic agents is greatly reduced.Over dose of muscle relaxants results in delayed recovery and residual neuromuscular blockade resulting in deleterious after effects.Patient has adequate surgical muscle relaxation or not, is variable from surgeon to surgeon and between surgeon and anesthetist. 9Muscle relaxation is monitored clinically by surgeons from tense muscles or by anesthetist from patient's breathing activity.It can be monitored by using gadgets with facial or thumb muscle twitches.
New computer based automatic methods uses this muscle twitches and automatically deliver the required dose of muscle relaxants. 10epth of muscle relaxation required for surgical procedures is comparable with laryngeal muscle relaxation required for endotracheal intubation.Sevoflurane is most common anesthetic agent used for intobations without muscle relaxants and intubations without muscle relaxants is preferred by > one third paediatric anaesthesiologists. 11Awad MT 12 found that sevoflurane with propofol produces rapid induction.Another studies depicted that propofol 2 mg/kg was better than 1 mg/kg with sevoflurane for excellent intu-bation condition. 13Blair JM 14 showed that sevoflurane is better than propofol and suxamethonium in children intubations.Sevoflurane is very popular in paediatric anesthesia because of its favorable properties.It produces satisfactory induction and intubation condition.It can be used for ambulatory and non-ambulatory paediatric surgeries. 15Gas induction has been safely used even in pyloromyotomy. 16Aqil M 17 found that sevoflurane with Fentanyl was supportive for intubation in adults.Shah TH 18 also found it possible to intubate children without neuromuscular block.
Rapid emergence properties of sevoflurane are comparable with desflurane. 19But the problem of post anesthesia excitement is very common with sevoflurane in paediatric patients. 20Also there is risk of nephrotoxicity with sevoflurane.
So if we have the modern volatile anaesthetic agents like sevoflurane then in paediatric population endotracheal intubation and surgical muscle relaxation can be safely achieved from it.

Conclusion
Our study concluded that in paediatric population the elective surgical procedures of groin region can be safely preceded alone with sevoflurane without using additional muscle relaxants.