Study of Rocuronium-Sugammadex as an Alternative to Succinylcholine-Cisatracurium in Microlaryngeal Surgery

Microlaryngeal surgery (ML) is a short procedure that requires a deep neuromuscular blockade to provide optimum surgical conditions. Succinylcholine is a relaxant widely used but involves numerous complications. One valid alternative is rocuronium, with a specific antagonist, sugammadex. The primary objective was to assess the surgical conditions in ML according to the relaxant. The secondary objectives were to assess intubation conditions and intraoperative and immediate postoperative adverse events.

STUDY DESIGN

Prospective randomized study.

METHODS

This was a prospective study of patients scheduled for ML randomized into two groups according to relaxant. Neuromuscular blockade was recorded after administration and during ML surgery. Surgical conditions were assessed using the ML Rating Scale, intubation conditions, remifentanil doses, intraoperative complications, surgery time, emergence time, and complications in the postanesthesia care unit.

RESULTS

Two hundred five patients were included (rocuronium = 103, succinylcholine = 102). Train-of-four values were higher for rocuronium, though the otorhinolaryngology surgical conditions were significantly better in that group (rocuronium = 5.54 ± 1.39 points; succinylcholine = 9.13 ± 1.99 points). Intubation conditions were similar in both groups. Remifentanil doses were higher for succinylcholine (P < .001) (rocuronium = 0.102 ± 0.05 μg/kg/min; succinylcholine = 0.201 ± 0.05 μg/kg/min). There were no differences in the duration of surgery, but the time to awakening was significantly longer for succinylcholine (rocuronium = 3.82 ± 1.38 minutes, succinylcholine = 9.18 ± 2.04 minutes, P < .001).

CONCLUSIONS

Rocuronium provides better surgical conditions and allows for the use of lower doses of remifentanil as compared to succinylcholine and cisatracurium in ML. This makes it possible to decrease the time to awakening and the complications associated with high doses of remifentanil.

LEVEL OF EVIDENCE

1b Laryngoscope, 131:E212-E218, 2021.

Accidental injection of succinylcholine into epidural space as a test dose

Inadvertent injection of nonepidural drugs into the epidural space is a rare situation, which is under-reported, and can lead to serious complications, such as cardiovascular and respiratory complications, paraplegia, or quadriplegia, and can worsen the patients' outcome from surgery. Succinylcholine administered epidurally leads to the appearance of fasciculation and shortness of breath and can prolong neuromuscular blockade. We report a case of accidental administration of 100 mg of succinylcholine via an epidural catheter as a test dose instead of 2 ml 0.5% bupivacaine in a patient planned for major abdominal surgery. After 2 min, the patient complained of shortness of breath; dysarthria; and fasciculation in the trunk, upper limbs, and face. This was managed with induction to general anesthesia (GA). In the postoperative period, no neurological or cardiovascular complications were observed. There is no adequate drug as an antidote of accidentally given nonepidural drugs via an epidural catheter. Succinylcholine given via epidural catheter has been shown to prolong neuromuscular blockade. Proper labeling and storage of syringes are of utmost importance for avoiding these unpleasant situations.

The Effect of Pregabalin on the Prevention of Succinylcholine-Induced Fasciculation and Myalgia

PURPOSE

This study evaluates the effect of pregabalin on fasciculation and myalgia after using succinylcholine.

DESIGN

This randomized double-blind prospective study was conducted among 100 patients aged 20 to 60 years old.

METHODS

Pregabalin (300 mg) and placebo (in capsule form) were placed in similar containers. The results were analyzed by SPSS 23 software, and statistical analysis consisted of χ² test and t test, and a P value less than .05 was considered significant.

FINDINGS

The mean pain score in the group receiving pregabalin was lower than the placebo group. According to the χ² test, there was a significant difference between the two groups in the frequency of fasciculation (P = .003). Mean fasciculation severity in the pregabalin group was lower than placebo group. According to t test, there was a significant difference in the mean fasciculation severity between the two groups (P = .002).

CONCLUSIONS

This study showed that 300 mg of pregabalin was effective in reducing postoperative fasciculation and myalgia in patients treated with succinylcholine.

Supramolecular therapeutics to treat the side effects induced by a depolarizing neuromuscular blocking agent

Succinylcholine (Sch) is the only depolarizing neuromuscular blocking agent widely used for rapid sequence induction in emergency rooms. Unfortunately, a variety of (sometimes lethal) adverse effects, such as hyperkalemia and cardiac arrest, are associated with its use, and currently there are no specific antidotes to reverse Sch or to treat these side-effects. Methods: The binding behaviors of Sch and several synthetic receptors, including cucurbit[7]uril, sulfo-calix[4]arene and water-soluble carboxylatopillar[6]arene (WP[6]), were first investigated. With a mouse model, a leathal dose of Sch was selected for evaluation of the antidotal effects of these synthetic receptors on Sch induced mortality. The antidotal effects of a selected synthetic receptor, WP[6], on Sch induced cardiac arrhythmias, hyperkalemia, rhabdomyolysis and paralysis were subsequently evaluated with rat and mouse models. The reversal mechanism was also investigated at a cellular level. Results: All of these macrocyclic molecules exhibited relatively high binding affinities with Sch in vitro. In a Sch-overdosed mouse model, immediate injection of these synthetic receptors right after Sch administration increased the overall survival rate, with WP[6] standing out with the most effective antidotal effects. In addition, administration of WP[6] also reversed the paralysis induced by Sch in a mouse model. Moreover, infusion of WP[6] to Sch-overdosed rats reduced the incidence of cardiac arrhythmia, inhibited the otherwise abnormally high serum potassium levels, and relieved the muscular damage. At the cellular level, WP[6] reversed the Sch induced depolarization and reduced the efflux of intracellular potassium. Conclusion: Synthetic receptors, particularly WP[6], exhibited high binding affinities towards Sch, and presented a significant potential as supramolecular therapeutics to treat the various side effects of Sch by specifically sequestering Sch in vivo.

Medical alert tattoos-A pinch of style along with patient safety

The use of medical tattoos can potentially be life-saving. We present a 16-year-old patient who chose to tattoo a medical condition on her forearm. Her tattoo is more extensive than most medical tattoos and shows the measures a mother will take to ensure her daughter's safety. To our knowledge, there are no published guidelines recommending an ideal location or symbology for a medical tattoo. Such guidelines would be useful to artists, as well as to medical personnel in emergencies if the patient has a tattoo.

Prolonged neuromuscular block associated with cholinesterase deficiency

RATIONALE

Hereditary genetic mutations may cause congenital cholinesterase deficiency. When succinylcholine and mivacurium are applied on cholinesterase-deficient patients during general anesthesia, prolonged postoperative asphyxia occurs, which is an uncommon but very serious complication.

PATIENT CONCERNS

A previously healthy 30-year-old female presented prolonged spontaneous breathing recovery after general anesthesia.

DIAGNOSES

After the patient's postoperative spontaneous breathing recovery delayed, the plasma cholinesterase was found to be 27 U/L, which was far below the normal level (4000 U/L to 13500 U/L). This patient had no disease that can cause plasma cholinesterase deficiency and was therefore diagnosed as congenital cholinesterase deficiency.

INTERVENTIONS AND OUTCOMES

The patient was sent to the intensive care unit (ICU) intubated for mechanical ventilator support, and on the next day the tracheal tube was removed without any complications when her spontaneous respiration resumed.

LESSONS

Cholinesterase is an enzyme secreted by the liver involved in many physiological processes in human body. Plasma cholinesterase commonly contains acetylcholinesterase (AChE) and butyrylcholinesterase (BChE). When succinylcholine and mivacurium are applied on patients with cholinesterase-deficiency during general anesthesia, prolonged postoperative asphyxia occurs, which is an uncommon but very serious complication. Lately, new evidences have suggested that hereditary genetic mutations may be responsible for congenital cholinesterase deficiency.

Succinylcholine-Induced Rhabdomyolysis in Adults: Case Report and Review of the Literature

PURPOSE

A case of succinylcholine (SCh) and sevoflurane as a probable cause of rhabdomyolysis in an adult is presented, along with a review of the relevant literature and strategies for prevention.

SUMMARY

A nondiabetic, morbidly obese 32-year-old female developed rhabdomyolysis after administration of SCh and sevoflurane for diagnostic procedures of 30 minutes' duration. Thirty-three hours following anesthesia, the patient developed diffuse muscle tenderness and progressive weakness with a creatinine kinase (CK) of 4319 U/L. Urinalysis findings indicated contamination, a white blood cells of 12.1 × 10³/μL was stress induced, while all other labs were normal. Following 26 hours of intravenous fluids, the patient's CK decreased to 1243 U/L, with pain responsive to acetaminophen and improved mobility, resulting in discharge. With a lack of reasonable alternative causes and a temporal association of symptoms, procedural medication-induced rhabdomyolysis was suspected. Based on Naranjo scale evaluation, SCh and sevoflurane were probable causes of rhabdomyolysis. We reviewed the literature for SCh-induced rhabdomyolysis among adults and found 10 cases. The majority of patients received halogenated anesthesia (HA) and prophylaxis for SCh myopathy, with no known personal or family history of neuromuscular disorders (NMD) reported.

CONCLUSION

Rhabdomyolysis was observed in a woman following the administration of SCh and sevoflurane for diagnostic procedures lasting 30 minutes. While avoidance is possible in adults with histories of NMDs, a high index of suspicion for occurrence of rhabdomyolysis is needed whenever combining SCh with HA in all adults.

Rapid Sequence Intubation in Traumatic Brain-injured Adults

Deciding on proper medication administration for the traumatic brain injury (TBI) patient undergoing intubation can be daunting and confusing. Pretreatment with lidocaine and/or vecuronium is no longer recommended; however, high-dose fentanyl can be utilized to help blunt the sympathetic stimulation of intubation. Induction with etomidate is recommended; however, ketamine can be considered in the proper patient population, such as those with hypotension. Paralysis can be performed with either succinylcholine or rocuronium, with the caveat that rocuronium can lead to delays in proper neurological examinations due to prolonged paralysis. Recommendations for post-intubation continuous sedation medications include a combination propofol and fentanyl in the normotensive/hypertensive patient population. A combination midazolam and fentanyl or ketamine alone can be considered in the hypotensive patient.

Low-dose Succinylcholine to Facilitate Laryngeal Mask Airway Insertion: A Comparison of Two Doses

Background and Aims:

Around the world, the use of the laryngeal mask airway (LMA) is becoming more common for different surgeries accounting for it being the dominant choice of airway in numerous surgeries. Although propofol is known to blunt the laryngeal reflexes often patient movement, coughing, and gagging occur on insertion. This study aims to identify the optimum dose of succinylcholine required to facilitate LMA insertion comparing placebo, 0.1 mg/kg and 0.25 mg/kg of succinylcholine. Further objectives were to compare (a) the overall insertion conditions of the LMA, (b) the number of insertion attempts, (c) the amount of propofol consumption, and (d) the hemodynamics in the three groups.

Setting and Design:

This is a prospective, double-blinded, randomized control trial of 283 patients randomized into three groups-placebo, 0.1 mg/kg and 0.25 mg/kg of succinylcholine. It was done in the day case theatres of a tertiary hospital in Southern India.

Subjects and Methods:

Patients were induced with 2 mg/kg of propofol, after 2 μg/kg of fentanyl. The study drug was given after loss of consciousness. After 60 s, a classic LMA was inserted by the standard method by a single investigator. Jaw relaxation, coughing, gagging, movement, laryngospasm, ease of insertion, number of attempts, propofol usage, and hemodynamics were assessed.

Statistical Analysis:

Statistical methods used were analysis of variance with Bonferroni's t-test, Chi-square test, and Fisher's test. P < 0.05 was considered statistically significant.

Results:

Jaw relaxation was significantly better in the 0.25 mg/kg succinylcholine group. There was no significant difference in coughing and gagging in the groups, but patient movement was more in the placebo group. Two patients in the placebo group experienced partial laryngospasm. Overall insertion conditions were significantly better in the 0.25 mg/kg group compared to the other two groups. Propofol consumption was significantly more in the placebo group.

Conclusions:

The study concludes that 0.25 mg/kg succinylcholine facilitates insertion of the LMA.

Spectroscopic determination of succinylcholine in dosage forms using eosin Y

Two simple and sensitive analytical assay methods using spectrophotometry and spectrofluorimetry techniques were developed for the estimation of succinylcholine chloride (SUC) in pharmaceutical preparations. The suggested methods are based on the formation of an ion pair complex formed between the drug and eosin Y spectrophotometrically (Method I), or the suppressive effect of succinylcholine on the native fluorescence property of eosin Y (Method II). The spectrophotometric method (Method I) involves measuring the absorbance of the complex between succinylcholine and eosin Y at 550 nm in Britton Robinson buffer of pH 3. However, the spectrofluorimetric method (Method II) involves measuring the quenching effect of the studied drug on the native fluorescence property of eosin Y at the same pH at 550 nm after excitation at 480 nm. The absorbance versus concentration of the drug is rectilinear over the range of 0.5 to 15 μg/ml. The formation constant was 3.5 × 10⁴ and the Gibb's free energy change was -2.5 × 10⁴  J/mol. In Method II, the relative fluorescence intensity was directly proportional to SUC concentration over the range of 0.05 to 1 μg/ml. The proposed methods allowed a successful application to the estimation of succinylcholine ampoules. An explanation of the reaction pathway was postulated.

Malignant Hyperthermia: A Review

Malignant hyperthermia is an uncommon, but potentially lethal condition that may be encountered during the perioperative period. There is wide variability in the manner in which malignant hyperthermia may manifest. For a patient to survive a malignant hyperthermia crisis, prompt recognition and treatment is of paramount importance. Perioperative nurses play a pivotal role in the successful management of malignant hyperthermia. The fictitious case study presented in this paper describes the identification, presentation, pathophysiology, and treatment of a general anesthesia patient with fulminant malignant hyperthermia.

Optimal dose of succinylcholine for laryngeal mask airway insertion: systematic review, meta-analysis and metaregression of randomised control trials

OBJECTIVES

To evaluate the optimal dose of succinylcholine for laryngeal mask airway (LMA) insertion and all related morbidities.

DESIGN

Systematic review, meta-analysis and metaregression of randomised controlled trials (RCTs).

DATA SOURCE AND STUDY ELIGIBILITY CRITERIA

A comprehensive search of RCTs in the PubMed, Embase, the Cochrane Library and the ClinicalTrials.gov registry up to July 2016 and articles that evaluated the use of succinylcholine chloride for LMA insertion were included in the analyses. The relative risk (RR) and the corresponding 95% CIs were determined.

INTERVENTION

Succinylcholine as the coinduction agent and the doses were divided into mini (≤0.3 mg/kg) and low (0.3-1.0 mg/kg) doses for dose-dependent effect analyses.

PRIMARY AND SECONDARY OUTCOMES

The primary outcome was the first-attempt LMA insertion failure rate. Secondary outcomes included all related adverse events.

RESULTS

Data from 10 RCTs comprising 625 participants showed that succinylcholine reduced the first-attempt LMA insertion failure rate (RR, 0.22; 95% CI 0.12 to 0.43), coughing and gagging (RR, 0.26; 95% CI 0.15 to 0.45) and laryngospasm (RR, 0.14; 95% CI 0.05 to 0.39). The use of succinylcholine did not result in a significant increase of postoperative myalgia (RR, 2.58; 95% CI 0.79 to 8.44) and did not reduce the risk of postoperative sore throat (RR, 0.76; 95% CI 0.55 to 1.03). Subgroup analysis further showed that low-dose succinylcholine reduced the LMA insertion failure rate and its related coughing and gagging when compared with mini dose.

CONCLUSION

The use of succinylcholine compared with none can facilitate LMA insertion and reduce insertion-related reflexes without significant postoperative myalgia. However, additional prospective studies with a larger sample size are required to fully evaluate the dose-dependent effect and complications of succinylcholine for LMA insertion.

Comparison of atracurium and methocarbamol for preventing succinylcholine-induced muscle fasciculation: A randomized controlled trial

Fasciculation is a minor adverse effect of succinylcholine and may be an unpleasant experience for patient. The aim of this study was to compare the use of atracurium and methocarbamol to decrease the occurrence and severity of succinylcholine-induced muscle fasciculation. Fifty-nine adults with American Society of Anesthesiologists I or II hospitalized for elective surgery were randomly assigned to two groups: Group A (n = 29) who received succinylcholine 1 mg/kg body weight (BW) intravenously followed by 0.2–0.5 mg/kg BW atracurium and patients in Group B (n= 29) who received succinylcholine 1 mg/kg BW intravenously followed by methocarbamol 0.2–0.5 mg/kg BW. Anesthesia was induced in all patients with thiopental sodium 3–5 mg/kg. Fasciculation was scored on a four-point (0–4) Likert scale. There were no statistically significant differences in demographic variables between two groups, whereas in Group A, 27 patients (93.1%) suffered from mild fasciculation and two (6.9%) from moderate fasciculation. In Group B, twenty patients (68.9%) suffered from mild fasciculation, five (17.2%) from moderate fasciculation, and four (13.9%) from severe fasciculation. The difference between the groups was statistically significant (P < 0.05). Atracurium is more effective than methocarbamol in decreasing the occurrence and severity of succinylcholine-induced fasciculations. In addition, the use of methocarbamol before succinylcholine administration can decrease the incidence of severe fasciculation.

To Evaluate the Efficacy of Intravenous Infusion of Dexmedetomidine as Premedication in Attenuating the Rise of Intraocular Pressure Caused by Succinylcholine in Patients Undergoing Rapid Sequence Induction for General Anesthesia: A Randomized Study

Context:

Laryngoscopy and intubation performed during RSI lead to choroidal blood volume increase and an eventual rise in intraocular pressure (IOP). Use of succinylcholine (SCh) causes an undesirable rise in IOP which is further aggravated by laryngoscopy and endotracheal intubation. Dexmedetomidine is a highly selective centrally acting α₂ adrenergic agonist that has IOP lowering properties.

Aims:

This study aims to evaluate the efficacy of intravenous (i.v.) infusion of dexmedetomidine (0.5 μg/kg) as premedication in attenuating the rise of IOP and adverse effect if any caused by SCh in patients undergoing RSI for general anesthesia.

Settings and Design:

This was a double-blind, randomized trial.

Subjects and Methods:

Sixty adult patients in the age group of 20–50 years scheduled for elective surgeries under general anesthesia. Group I (dexmedetomidine group) (n = 30) received i.v. infusion of dexmedetomidine (0.5 μg/kg) and Group II (control group) (n = 30) received i.v. infusion of 50 ml normal saline as premedication

Statistical Analysis Used:

The analysis was done using Statistical Package for Social Sciences Version 15.0 statistical Analysis Software.

Results:

It was observed that Group I (dexmedetomidine group) had a better attenuating effect over the increases in IOP in patients undergoing RSI for general anesthesia using SCh. An increase in IOP was seen in Group II (control group) patients with RSI.

Conclusions:

The findings in the present study indicate that i.v. dexmedetomidine effectively attenuates the increases in IOP with an additional advantage of control on hemodynamic responses following RSI.

The Influence of Two Different Doses of Magnesium Sulfate on Intraocular Pressure Variations after Injection of Succinylcholine and Endotracheal Intubation: A Prospective, Randomized, Parallel Three-Arm, Double-blind, Placebo-controlled Clinical Trial

Background:

The use of succinylcholine for rapid sequence induction in patients with open globe injuries may be detrimental to the eye.

Aim:

The aim of this study is to determine if the premedication with magnesium sulfate (MgSO₄) could attenuate the increase in intraocular pressure (IOP) associated with succinylcholine injection and intubation.

Setting:

Operation theaters in a tertiary care University Hospital between December 2014 and July 215.

Design:

This was a prospective, randomized, parallel three-arm, double-blind, placebo-controlled clinical trial.

Participants:

One hundred and thirteen patients’ physical status ASA Classes I and II underwent elective cataract surgery under general anesthesia.

Patients and Methods:

These patients allocated into three groups: Group C (control group) received 100 ml normal saline, Group M1 received 30 mg/kg MgSO₄ in 100 ml normal saline, and Group M2 received 50 mg/kg MgSO₄ in 100 ml normal saline. IOP, mean arterial pressure (MAP), and heart rate (HR) reported at 5-time points related to study drug administration. In addition, any adverse effects related to MgSO₄ were recorded. Intragroup and between-groups differences were examined by analysis of variance test.

Results:

We noticed a significant decrease in IOP in M1 (n = 38) and M2 (n = 37) groups as compared with C group (n = 38) after study drugs infusion, 2 and 5 min after intubation, P < 0.001. While the difference between M1 and M2 groups was insignificant, P = 0.296 and P = 0.647, respectively. There was a significant decrease in MAP and HR in M1 and M2 groups as compared with C group 2 and 5 min after intubation, P = 0.01. While the difference between M1 and M2 groups was insignificant, P = 1.

Conclusion:

MgSO₄ 30 mg/kg as well as 50 mg/kg effectively prevented the rise in IOP, MAP, and HR associated with rapid sequence induction by succinylcholine and endotracheal intubation.

Effects of low-dose ketamine on succinylcholine-induced postoperative myalgia in outpatient surgeries: a randomized, double-blind study

Objective

Despite the many complications of succinylcholine, it is still widely used as a superior muscle relaxant for rapid sequence induction. One of these complications is postoperative myalgia (POM). The aim of this study was to investigate the prophylactic effect of low-dose ketamine on the incidence and severity of POM.

Materials and methods

In this double-blind clinical study, a total of 148 patients scheduled for general anesthesia were randomly divided into two equal groups. Initially, in Group K, 0.5 mg/kg of ketamine was injected intravenously, whereas in Group N, the same volume (5 mL) of normal saline was injected. Thereafter, anesthesia was induced in all patients, by injecting 1.5 mg/kg of fentanyl and 2 mg/kg of propofol intravenously. Following the loss of eyelid reflex, 1.5 mg/kg of succinylcholine was injected intravenously as a muscle relaxant and then the patients were intubated. POM was defined as a pain with no surgical interferences, and its intensity was graded based on a four-point scale. The incidence and severity of myalgia were assessed by a blinded observer 24 hours after surgery.

Results

In terms of demographic data, the results of this study showed that there is no significant difference between patients in both groups (P>0.05). Overall, the incidence of POM in Group K was significantly less, when compared with Group N (P<0.05), but both groups were comparable based on the grade 2 of POM. After the induction of anesthesia, the systolic and diastolic blood pressure values were found to reduce in both groups (P<0.05). However, the changes were somehow similar, and repeated measures of variance analysis showed no significant difference in the two study groups (P>0.05).

Conclusion

The addition of 0.5 mg/kg of ketamine to propofol for the induction of anesthesia can be effective in reducing the incidence of low-grade POM.

Malignant hyperthermia in a 6-month-old infant

Malignant hyperthermia (MH) is a rare hypermetabolic disorder of skeletal muscles that manifests as a life-threatening crisis in susceptible individuals, after exposure to triggering agents, most commonly halothane and succinylcholine. MH presents with multiple nonspecific signs and laboratory findings such as tachycardia, hyperthermia, hypercarbia, acidosis, and muscle rigidity. Caffeine halothane contracture test is not available at most centers in India. Larach et al. have described a clinical grading scale for determining the MH raw score based on clinical findings and biochemical tests. The high degree of suspicion, early recognition and aggressive treatment should commence immediately. It is imperative to avoid triggering agents, such as volatile anesthetics and succinylcholine, and promote the use of total intravenous anesthesia in MH susceptible patients. We report a case of 6-month-old child undergoing laparotomy under general anesthesia, who presented with signs and symptoms of MH, had MH rank 5 and raw score 36.

Comparison of rocuronium at two different doses and succinylcholine for endotracheal intubation in adult patients for elective surgeries

Background:

The effects of rocuronium at two different doses, that is, 0.6 mg/kg (2 × ED95) and 0.9 mg/kg (3 × ED95), were compared with succinylcholine (2 mg/kg) when used for endotracheal intubation in adult patients for elective surgeries under general anesthesia.

Materials and Methods:

Ninety patients were divided into three groups of 30 each. Groups A, B received injection rocuronium at 0.6 mg/kg, 0.9 mg/kg respectively and Group C received succinylcholine at 2 mg/kg. Onset of action of relaxant, intubation conditions, time taken to intubate and duration of action were compared.

Statistical Analysis Used:

To compare the statistical difference in the age, weight, height of the study subjects, onset of action of relaxant, intubation conditions, time taken to intubate, and duration of action analysis of variance and unpaired t-test were used.

Results:

The onset time was considerably shorter with rocuronium 0.9 mg/kg than 0.6 mg/kg. The onset time of rocuronium 0.9 mg/kg was found to be significantly longer than succinylcholine 2 mg/kg. Time taken to intubate was shortest with succinylcholine 2 mg/kg. The time taken to intubate with the rocuronium 0.9 mg/kg was found to be comparable to that of rocuronium 0.6 mg/kg. Intubation score of rocuronium 0.9 mg/kg was the best (17.75), which was comparable with succinylcholine. However, the intubation score obtained with rocuronium 0.6 mg/kg was inferior. Duration of action was shortest with succinylcholine. The duration of action is prolonged when the dose of rocuronium is increased from 0.6 to 0.9 mg/kg.

Conclusion:

Rapid sequence induction of anesthesia with propofol and fentanyl, succinylcholine allowed a more rapid endotracheal intubation sequence and created superior intubation conditions than rocuronium. However, the technique of using a large dose of rocuronium to achieve perfect conditions for tracheal intubation may have application whenever succinylcholine is relatively contraindicated.

Endotracheal intubation without muscle relaxants in children using remifentanil and propofol: Comparative study

Introduction:

Endotracheal intubation is essential during general anesthesia and muscle relaxant drugs provide ideal conditions for this purpose. The objective of this study was to evaluate the intubating condition of remifentanil combined with propofol without muscle relaxant.

Materials and Methods:

In this prospective randomized study, 60 children aged 3-12 years, American Society of Anesthesiologists physical status I and II were included. All the children were premedicated with 0.05 mg/kg midazolam and 1.5 mg/kg lidocaine 5 min before the induction of anesthesia with 3 mg/kg propofol. Then, they were allocated randomly to receive either 2 μg/kg remifentanil (group R) or 1.5 mg/kg succinylcholine (group S). Tracheal intubation was attempted 90 s after the administration of propofol. The quality of intubation was assessed by using Copenhagen score based on jaw relaxation, ease of laryngoscopy, position of vocal cord, coughing and limb movement. Heart rate and blood pressure were recorded before and after induction, and 1, 3, 5 min after intubation.

Results:

There was no significant difference in intubating condition between the two groups (P = 0.11). Intubation condition was excellent in 26 of 30 (86.7%) patients in the group R compared with 30 (100%) patients in the group S. We observed significant difference in heart rate and systolic blood pressure over time between two groups (P = 0.02, P = 0.03 respectively). After intubation, we had higher heart rate and systolic blood pressure with a significant difference in group S compared with group R (P = 0.006, P = 0.018). None of the children had a chest rigidity, laryngospasm, and hypoxia.

Conclusions:

In premedicated children, propofol-remifentanil combination provides adequate conditions for tracheal intubation that is comparable with succinylcholine. Hemodynamic response to laryngoscopy and tracheal intubation was controlled better in group R.

Efficacy of alpha2 agonists in obtunding rise in intraocular pressure after succinylcholine and that following laryngoscopy and intubation

Context:

Elevation of intraocular pressure (IOP) is an inherent and inadvertent association with the use of succinylcholine and alpha₂ agonists can be used to obtund this effect.

Aims:

The study was aimed to assess the efficacy of intravenous dexmedetomidine and clonidine premedication in attenuating rise in IOP during laryngoscopy and intubation following administration of succinylcholine.

Settings and Design:

This prospective, observational study was conducted in 40 patients aged 20–60 years undergoing non ophthalmic surgical procedures.

Subjects and Methods:

For patients in Group D, dexmedetomidine 0.4 mcg/kg and in Group C clonidine 1 μg/kg over 10 min was administered before induction. All patients were induced with propofol. Laryngoscopy and intubation were performed 1 min after administration of succinylcholine 2 mg/kg.

Statistical Analysis Used:

Mann–Whitney, Chi-square and Wilcoxon tests.

Results:

Mean baseline IOP of both groups were comparable (15.4 ± 2.6 vs. 14.7 ± 2.3). Following premedication and induction, IOP decreased in both groups and the reduction was significantly more in Group D. Following administration of succinylcholine and 1 min after intubation IOP raised and exceeded the baseline value in Group C (16.0 ± 1.6 and 18.6 ± 2.2). Though there was an increase in IOP in Group D (12.0 ± 1.9 and 14.0 ± 2.1), it did not reach up to baseline values. Then there was a gradual reduction in IOP in both groups at 3, 5, and 10 min and Group D continued to have a significantly low IOP than Group C up to 10 min.

Conclusions:

Dexmedetomidine 0.4 μg/kg resulted in a reduction of IOP and blunted the increase in IOP, which followed administration of succinylcholine, laryngoscopy, and intubation. Though clonidine 1 μg/kg reduced IOP, it did not prevent rise in IOP following succinylcholine, laryngoscopy, and intubation.

Statins and succinylcholine interaction: A cause of concern for serious muscular damage in anesthesiology practice!

Statins are being extensively used in cardiac patient throughout the globe. Succinylcholine has been the mainstay of profound relaxation during induction and intubation of anesthesia for almost six decades now. The interactive properties of these drugs have been of major concern during routine anesthesiology practice in the last few years. However, no major research trial, prospective studies or meta-analysis are available, which can truly allay the fears of possible potential negative synergistic interactions between these two commonly used drugs. Whatever the evidence is available is hardly enough to support a positive outcome and the results have been drawn from observations of only few small studies. As a result, a continuous need among anesthesiologist fraternity is felt to arrive at a suitable inference, which can predict definite consequences of this synergistic interaction. The present article reviews some of the important observations of few handful studies which were carried out to observe any potential adverse interactions between succinylcholine and statins.

Management of malignant hyperthermia: diagnosis and treatment

Malignant hyperthermia is a potentially lethal inherited disorder characterized by disturbance of calcium homeostasis in skeletal muscle. Volatile anesthetics and/or the depolarizing muscle relaxant succinylcholine may induce this hypermetabolic muscular syndrome due to uncontrolled sarcoplasmic calcium release via functionally altered calcium release receptors, resulting in hypoxemia, hypercapnia, tachycardia, muscular rigidity, acidosis, hyperkalemia, and hyperthermia in susceptible individuals. Since the clinical presentation of malignant hyperthermia is highly variable, survival of affected patients depends largely on early recognition of the symptoms characteristic of malignant hyperthermia, and immediate action on the part of the attending anesthesiologist. Clinical symptoms of malignant hyperthermia, diagnostic criteria, and current therapeutic guidelines, as well as adequate management of anesthesia in patients susceptible to malignant hyperthermia, are discussed in this review.

Functional and genetic characterization of clinical malignant hyperthermia crises: a multi-centre study

BACKGROUND

Malignant hyperthermia (MH) is a rare pharmacogenetic disorder which is characterized by life-threatening metabolic crises during general anesthesia. Classical triggering substances are volatile anesthetics and succinylcholine (SCh). The molecular basis of MH is excessive release of Ca2+ in skeletal muscle principally by a mutated ryanodine receptor type 1 (RyR1). To identify factors explaining the variable phenotypic presentation and complex pathomechanism, we analyzed proven MH events in terms of clinical course, muscle contracture, genetic factors and pharmocological triggers.

METHODS

In a multi-centre study including seven European MH units, patients with a history of a clinical MH episode confirmed by susceptible (MHS) or equivocal (MHE) in vitro contracture tests (IVCT) were investigated. A test result is considered to be MHE if the muscle specimens develop pathological contractures in response to only one of the two test substances, halothane or caffeine. Crises were evaluated using a clinical grading scale (CGS), results of IVCT and genetic screening. The effects of SCh and volatile anesthetics on Ca2+ release from sarcoplasmic reticulum (SR) were studied in vitro.

RESULTS

A total of 200 patients met the inclusion criteria. Two MH crises (1%) were triggered by SCh (1 MHS, 1 MHE), 18% by volatile anesthetics and 81% by a combination of both. Patients were 70% male and 50% were younger than 12 years old. Overall, CGS was in accord with IVCT results. Crises triggered by enflurane had a significantly higher CGS compared to halothane, isoflurane and sevoflurane. Of the 200 patients, 103 carried RyR1 variants, of which 14 were novel. CGS varied depending on the location of the mutation within the RyR1 gene. In contrast to volatile anesthetics, SCh did not evoke Ca2+ release from isolated rat SR vesicles.

CONCLUSIONS

An MH event could depend on patient-related risk factors such as male gender, young age and causative RyR1 mutations as well as on the use of drugs lowering the threshold of myoplasmic Ca2+ release. SCh might act as an accelerant by promoting unspecific Ca2+ influx via the sarcolemma and indirect RyR1 activation. Most MH crises develop in response to the combined administration of SCh and volatile anesthetics.