Anesth Prog 37:296-300 1990
Submental Administration of Succinyicholine in Children
Ronald J. Redden, DDS, Mike Miller, DDS, Robert L. Campbell, DDS Department of Oral & Maxillofacial Surgery Medical College of Virginia, Richmond, Virginia
During inhalation induction of the pediatric patient, laryngospasm can develop before intravenous access has been established. The intramuscular administration of succinylcholine is commonly used in such instances. This study was designed to determine if the injection of succinylcholine by an extraoral submental approach would be an acceptable method of terminating laryngospasm when compared to conventional intramuscular sites. Following induction with halothane and nitrous oxide in oxygen, a total of fifteen ASA 1 children were given 3.0 mg/kg intramuscular succinylcholine either intralingually by a submental approach, or using the upper leg musculature in order to electromyographically measure the time to maximum (or 90 percent depression from baseline) twitch depression. The intralingual submental injection had a mean twitch depression of 265 + 62.5 seconds compared to the quadriceps femoris at 295 + 42.6 seconds. A group with digital massage of the intralingual injection site produced a mean depression time of 133 ± 11.9 seconds and was also the only group providing 100% success rate in reaching the desired twitch depression level. This may suggest that the operator should consider digital massage to produce a more predictable and desirable result.
come a life-threatening occurrence, especially prior to establishing venous access. The intramuscular administration of succinylcholine has been proven successful in such instances to assure airway patency while attempts are made at placing an intravenous line. Considering the vascularity of the tongue and floor of mouth musculature, theoretically an injection of a muscle relaxing agent (i.e., succinylcholine) into this area may significantly hasten the drug response and decrease the length of time that laryngospasm would persist. One problem often seen when laryngospasm occurs is the patient's jaws are frequently locked closed, making the intra-oral tongue injection nearly impossible. This study was designed to determine if the injection of succinylcholine into the tongue musculature through an extra-oral submental approach would be a safe and more rapid method of terminating laryngospasm when compared to conventional intramuscular sites. In addition, data was collected to assess whether or not digital massage of the submental area after injection would have any effect on the adsorption and response to succinylcholine.
METHOD Fifteen ASA Class 1 children weighing between 12 and 33 kilograms were randomly divided into three groups: five received 3.0 mg/kg of succinylcholine intralingually via the submental approach without massage (Group 1), five received 3.0 mg/kg succinylcholine by the same route plus digital massage of the post-injection site (Group 2), and five were given 3.0 mg/kg succinylcholine into the quadriceps femoris muscle of the upper leg (Group 3). The injection volume, which was limited to a maximum of 3cc in order to avoid the possibility of airway obstruction, was given intralingually with a 26 1/2 needle 1 3/8 inches in length. The patients were scheduled for procedures such as routine oral surgery (extractions, etc.), restorative denistry, cleft lip and palate surgery, tonsillectomy and myringotomy, with all children reporfing
In pediatric anesthesia, the development of laryngospasm during induction with a volatile agent can beReceived February 1, 1990; accepted August 21, 1990. Address correspondence to Dr. Redden, 1908 Stonegate, Denton, TX 76205. © 1990 by the American Dental Society of Anesthesiology
ISSN 0003-3006/90/$3.50
296
Redden et al. 297
Anesth Prog 37:296-300 1990 ANESTHESIA NEUROMUSCULAR TRANSMISSION MONITORING SYSTEM % Response
dl
100
75
50
25
Time:
,r:--.
O
TIO%
-
0
2.5
5
7.5
10
Time from injection to 10% response is 142 seconds
Figure 1. Baseline electromyographic data was collected in to a 2 Hz train-of-four stimulus applied at twenty second intervals. The EMG response was noted and the time following succinylcholine injection to ten percent remaining electrical response (or maximal twitch depression) was calculated. response
negative past medical histories for serious disorders (e.g., congenital heart defects or neuromuscular diseases). Each group was induced with halothane, nitrous oxide and oxygen, and general anesthesia maintained with 1.0 to 1.5% halothane mixed with 60% nitrous oxide in oxygen. Monitors including electrocardiogram, blood pressure, precordial stethoscope, pulse oximeter and EMG/twitch monitor electrodes were applied prior to induction if physically tolerated by the patient, or as soon as possible after induction. An intravenous line was established with normal saline solution and atropine (0.01 mg/kg) and dexamethasone (6.0 mg) given prior to the administration of any succinylcholine. A train-of-four stimulus was applied and baseline electromyographical data corresponding to 100% twitch response was recorded through an IBM PC XT computer and displayed in bar graph form on the visual monitor as well as on printed data. Two minutes of baseline electromyographical data was collected in response to a 2 Hertz train-of-four stimulus applied at twenty second intervals with data collected simultaneously. A 2% succinylcholine (20 mg/cc) injection was then given and the time from injection to a maximum twitch depression, or 90% reduction from baseline electrical activity, was recorded (Figure 1). Once this criteria was met, intubation was performed and the operative procedure started. The electrocardiogram was under continuous observation and rhythm strips were recorded for arrhythmias that could be related to succinylcholine administration.
RESULTS From the data collected, the mean elapsed time from a ten percent electrical response in Group 1 (intralingual without massage) was 265 + 62.5 seconds
injection to
(Table 1). In this group, depression to ten percent remaining electrical activity was never achieved in two of the five children. With Group 2 (intralingual with massage) the mean time to 90% twitch depression was 133 ± 11.9 seconds with all participants in this group reaching the desired level of twitch depression. The use of the quadriceps femoris muscle in Group 3 resulted in a mean time to 90% depression calculated at 295 ± 42.6 seconds. Again, failure to reach 90% twitch reduction was recorded in three of five patients from this group. Using this particular method of measuring electrical depression, the patients in Groups 1 and 3 showed a similar time period before 90% depression was reached from IM injection alone, where the Group 2 patients exhibited the most consistent results and a shorter time period from baseline to a ten percent electrical activity. Throughout the succinylcholine post-injection period there were no arrhythmias noted with EKG monitoring. All patients in this study were successfully intubated using this method, and there were no clinical signs of any upper airway compromise after the submental administration of muscle relaxants as all patients were examined during intubation with direct visual laryngoscopy.
DISCUSSION
Laryngospasms are an unforgettable and preventable, yet treatable episode experienced by virtually everyone who has administered pediatric general anesthesia. Defined by Fink1 as a prolonged glottic closure maintained beyond the initiating stimuli, laryngospasm is a protective autonomic reflex resulting in complete or partial spasmodic closure of the vocal cords. It is generally heralded by the recognizable signs of airway obstruction-inspiratory stridor or complete absence of any audible signs of air movement, thoraco-abdominal or "rocking horse" breathing, and the inability to ventilate the patient resulting in the oxyhemoglobin desaturation seen during pulse oximetry. The types of stimulation leading to laryngospasm include small amounts of blood or secretions, foreign bodies in the laryngeal region, irritating inhalation agents, pain, light anesthesia, and even neck traction or manipulation sometimes seen during attempts to thrust the jaw forward. Regardless of the cause, treatment must be systematic and immediate. When laryngospasm occurs during induction, the pharynx should be suctioned followed by continuous positive pressure delivery with 100% oxygen. Deepening the anesthesia with an inhalation agent is also recommended in an effort to reverse vocal cord hyperactivity. Most spasms can be broken by this combination alone with adequate return of ventilatory volumes and proper oxygenation provided. But if laryngospasm persists and the threat of hypoxia develops, then the administration of
Anesth Prog 37:296-300 1990
298 Administration of Succinylcholine in Children
Table 1. Summary of demographic characteristics and time to maximal twitch depression. Intralingual Without Massage-(Group 1)
Subject # 1 2 3 4 5 MEAN ± SEM (n = 5)
Weight (Kg) 15.0 16.0 13.0 18.5 16.0 15.7 ± 0.89
Age (Years) 7.3 4.0 2.5 3.2 3.5 4.1 ± 0.84
Time to Maximum Twitch Depression (Sec.) 237 142 126 382* 436* 265 ± 62.5
Intralingual With Massage-(Group 2)
Subject # 1 2 3 4 5 MEAN ± SEM (n =5)
Weight (Kg) 16.0 19.0 12.5 17.0 15.0 15.9 ± 1.1
Age (Years) 3.0 7.2 3.5 3.8 2.3 4.0 ± 0.85
Time To Maximum Twitch Depression (Sec.) 120 114 168 109 155 133 ± 11.9
Upper Leg: Quadriceps Femoris-(Group 3)
Subject #
Age (Years) 3.9 3.5 5.3 2.3 6.2 4.2 ± 0.68
Weight (Kg)
1 2 3 4 5 MEAN ± SEM (n = 5) * Failed to reach twitch depression greater than 90% reduction from baseline
succinylcholine is recommended to allow the anesthesiologist total control of the airway. Currently, the recommeded dose of intramuscularly administered succinylcholine in children ranges from 1.5-4.0 mg/kg with varying reported effects.2 In this study, the injection of a 2% succinylcholine at a dose of 3.0 mg/kg either intralingually or using upper leg musculature resulted in satisfactory intubating conditions in all patients. None showed significant cardiovascular changes or airway obstruction lingually, which contradicts Masse and Dunbar's observations3 in which the administration of the drug transorally into the tongue resulted in a 28 percent incidence of arrhythmias in children anesthetized with halothane and nitrous oxide. Some patients in their study developed arrhythmias after a second does of succinylcholine was administered which may explain some of the differences from our findings. Also absent during our study
19 16 33 12 21
20.2 ± 3.5
Time To Maximum Twitch Depression (Sec.) 400* 291 360* 152 270* 295 ± 42.6
were signs of pulmonary edema, which has been casually related to the use of intramuscular succinylcholine.4 Fulminant pulmonary edema has been reported in infants 3 to 8 weeks of age associated with intramuscular succinylcholine. Although the mechanism is unclear, the problems of gastric aspiration, sympathetic stimulation associated with transient systemic and pulmonary hypertension, and the in vitro relaxation of pulmonary veins by parasympathetic stimulation have all been implicated. Based on our electromyographic study, the non-massaged intralingual injection of succinylcholine produced a similar rate of neuromuscular twitch depression and consequent succinylcholine absorption at 265 + 62.5 seconds when compared to the intramuscular injections into upper leg musculature as reported by Sutherland and Beven with 240 ± 36 seconds respectively.5 The data in our study also show that the submental intralingual site of
Redden et al. 299
Anesth Prog 37:296-300 1990
administration results in an equal or better recorded onset time in comparison with the quadriceps femoris site tested. Although this onset time may be considered too long for emergency situations,5 an important consideration in treating laryngospasms form clinical experience with intramuscular succinylcholine in children has been that airway control after laryngospasm is achieved in less time than the time to maximum twitch depression.2 In other words, less than 100% depression of twitch response may be sufficient to perceive the benefits toward regaining control of the airway. In terms of technique, the submental approach offers certain advantages to other intramuscular sites. By eliminating the need to remove any clothing to expose the muscular site, this area is easily assessable and is included in the visual field of the anesthesiologist. While the intraoral type of intralingual injections have been advocated for the administration of succinylcholine, the extraoral submental approach may also eliminate serious potential problems. With the extraoral approach, a full face mask can be continually maintained and the airway supported which is especially important when oxygen delivery and positive pressure is paramount. In children where the functional residual capacity is less than that of an adult, hypoxia can rapidly follow even a brief period of hypoventilation, or obstructive laryngospasm, with bradycardia from vagal stimulation often contributing to the problem. Hypoxia presents a serious threat of permanent neurological damage and may also cause prodromal cardiac arrhythmias (i.e., PVC's) prior to bradycardia and cardiac arrest. An important physiological principle to remember in children is that the cardiac rate is the more influential determinant of cardiac output, 40% of which contributes to pediatric cerebral blood flow.7 This rate dependency in the child is largely due to the fact that changes in myocardial contractility (stroke volume) cannot compensate effectively in the child's heart when compared to the adult in maintaining the cardiac output. Because parasympathetic tone is most pronounced in infancy until at least 1 year of age with variable degrees of increased parasympathetic tone in earlier years of childhood, a decrease in cardiac rate due to vagal stimulation can also result in decreased cardiac output and hypotension. This type of stimulation frequently occurs with manipulation of the airway including endotracheal intubation.7 For this reason, it is often recommended that children be premedicated with a parasympathetic blocking drug such as atropine or glycopyrollate to oppose these predictable changes in heart rate. Additionally, with an extraoral injection there is a decreased chance of bleeding into the airway which can only potentiate a hyper-reflexic glottis and could go unnoticed for an undetermined amount of time. This technique may also be anatomically safer by avoiding potential airway
obstruction from a swollen tongue, or possible damage to associated oral structures including Wharton's Duct and the lingual nerve. Furthermore, there is a trend in this study which suggests that digital massage of the submental area following injection may lead to a more rapid and consistent level of muscular paralysis when compared to other peripheral injection sites, or even the submental area with no massage. Peripheral vasoconstriction in children resulting from extreme anxiety or a cold environment is common and can decrease the absorption of intramuscularly administered drugs. The end result is usually a delayed onset of action and lower plasma levels of injected drugs. Interestingly enough, massaging the submental injection site of Group 2 resulted in a decreased mean twitch depression time of 133 + 11.9 seconds. This simple routine reduced the effective time of an IM injection by approximately 50 percent according to this data. Without massage of either the submental or upper leg musculative sites, inconsistent levels of neuromuscular paralysis resulted with 5 of 10 patients in Groups 1 and 3 never reaching 90 percent twitch reduction. The massaged Group 2 also had a greater success rate achieving the desired depression level suggesting that digital massage not only decreases the maximum twitch depression time, but increases the efficacy of the muscle relaxing agent. Some massage is inadvertently performed to a certain extent via the anesthesiologist's hand placement over the full face mask and under the patient's mandible during "chin-up" head extension and mask adaptation for airway maintenance. In conclusion, the availability and effectiveness of the injection site and the ability of a single operator to alone provide airway maintenance, administer intramuscular succinylcholine, and perform digital massage supports the usefulness of the submental approach. And though the advantages of massage in a group using the upper leg musculature was not proven in this study, those reluctant to use the submental route may find that massage of the vastas lateralis or quadriceps femoris may prove to be more than just a kind gesture to a sore muscle.
REFERENCES 1. Fink BR. The Human Larynx: A Functional Study. Raven Press, New York, 1975:100. 2. Lui L. Dose Response to Intramuscular Succinylcholine in Children. Anesth 1981;55:599-602. 3. Mazee RI, Dunbar RW. Intralingual Succinylcholine Administration in Children. Anesth Analg 1968;47:605-615. 4. Cook DR. Pulmonary Edema in Infants: Possible Association with Intramuscular Succinylcholine. Anesth Analg 1981;60:220-223.
300 Administration of Succinylcholine in Children 5. Sutherland GA, Beven JC. Neuromuscular Blockade in Infants Following Intramuscular Succinylcholine in Two or Five Percent Concentrations. Can Anesth Soc J 1983;30:342346.
Anesth Prog 37:296-300 1990 6. Campbell RL. General Anesthesia for the Pediatric Patient. J Oral Maxillofac Surg 1982;40:497-506. 7. Anderson J. Pediatric Denistry: Infancy Through Adolescence. W. B. Saunders Company-Philadelphia, 1988:67-72.
Submental Administration of Succinyicholine in Children
Ronald J. Redden, DDS, Mike Miller, DDS, Robert L. Campbell, DDS Department of Oral & Maxillofacial Surgery Medical College of Virginia, Richmond, Virginia
During inhalation induction of the pediatric patient, laryngospasm can develop before intravenous access has been established. The intramuscular administration of succinylcholine is commonly used in such instances. This study was designed to determine if the injection of succinylcholine by an extraoral submental approach would be an acceptable method of terminating laryngospasm when compared to conventional intramuscular sites. Following induction with halothane and nitrous oxide in oxygen, a total of fifteen ASA 1 children were given 3.0 mg/kg intramuscular succinylcholine either intralingually by a submental approach, or using the upper leg musculature in order to electromyographically measure the time to maximum (or 90 percent depression from baseline) twitch depression. The intralingual submental injection had a mean twitch depression of 265 + 62.5 seconds compared to the quadriceps femoris at 295 + 42.6 seconds. A group with digital massage of the intralingual injection site produced a mean depression time of 133 ± 11.9 seconds and was also the only group providing 100% success rate in reaching the desired twitch depression level. This may suggest that the operator should consider digital massage to produce a more predictable and desirable result.
come a life-threatening occurrence, especially prior to establishing venous access. The intramuscular administration of succinylcholine has been proven successful in such instances to assure airway patency while attempts are made at placing an intravenous line. Considering the vascularity of the tongue and floor of mouth musculature, theoretically an injection of a muscle relaxing agent (i.e., succinylcholine) into this area may significantly hasten the drug response and decrease the length of time that laryngospasm would persist. One problem often seen when laryngospasm occurs is the patient's jaws are frequently locked closed, making the intra-oral tongue injection nearly impossible. This study was designed to determine if the injection of succinylcholine into the tongue musculature through an extra-oral submental approach would be a safe and more rapid method of terminating laryngospasm when compared to conventional intramuscular sites. In addition, data was collected to assess whether or not digital massage of the submental area after injection would have any effect on the adsorption and response to succinylcholine.
METHOD Fifteen ASA Class 1 children weighing between 12 and 33 kilograms were randomly divided into three groups: five received 3.0 mg/kg of succinylcholine intralingually via the submental approach without massage (Group 1), five received 3.0 mg/kg succinylcholine by the same route plus digital massage of the post-injection site (Group 2), and five were given 3.0 mg/kg succinylcholine into the quadriceps femoris muscle of the upper leg (Group 3). The injection volume, which was limited to a maximum of 3cc in order to avoid the possibility of airway obstruction, was given intralingually with a 26 1/2 needle 1 3/8 inches in length. The patients were scheduled for procedures such as routine oral surgery (extractions, etc.), restorative denistry, cleft lip and palate surgery, tonsillectomy and myringotomy, with all children reporfing
In pediatric anesthesia, the development of laryngospasm during induction with a volatile agent can beReceived February 1, 1990; accepted August 21, 1990. Address correspondence to Dr. Redden, 1908 Stonegate, Denton, TX 76205. © 1990 by the American Dental Society of Anesthesiology
ISSN 0003-3006/90/$3.50
296
Redden et al. 297
Anesth Prog 37:296-300 1990 ANESTHESIA NEUROMUSCULAR TRANSMISSION MONITORING SYSTEM % Response
dl
100
75
50
25
Time:
,r:--.
O
TIO%
-
0
2.5
5
7.5
10
Time from injection to 10% response is 142 seconds
Figure 1. Baseline electromyographic data was collected in to a 2 Hz train-of-four stimulus applied at twenty second intervals. The EMG response was noted and the time following succinylcholine injection to ten percent remaining electrical response (or maximal twitch depression) was calculated. response
negative past medical histories for serious disorders (e.g., congenital heart defects or neuromuscular diseases). Each group was induced with halothane, nitrous oxide and oxygen, and general anesthesia maintained with 1.0 to 1.5% halothane mixed with 60% nitrous oxide in oxygen. Monitors including electrocardiogram, blood pressure, precordial stethoscope, pulse oximeter and EMG/twitch monitor electrodes were applied prior to induction if physically tolerated by the patient, or as soon as possible after induction. An intravenous line was established with normal saline solution and atropine (0.01 mg/kg) and dexamethasone (6.0 mg) given prior to the administration of any succinylcholine. A train-of-four stimulus was applied and baseline electromyographical data corresponding to 100% twitch response was recorded through an IBM PC XT computer and displayed in bar graph form on the visual monitor as well as on printed data. Two minutes of baseline electromyographical data was collected in response to a 2 Hertz train-of-four stimulus applied at twenty second intervals with data collected simultaneously. A 2% succinylcholine (20 mg/cc) injection was then given and the time from injection to a maximum twitch depression, or 90% reduction from baseline electrical activity, was recorded (Figure 1). Once this criteria was met, intubation was performed and the operative procedure started. The electrocardiogram was under continuous observation and rhythm strips were recorded for arrhythmias that could be related to succinylcholine administration.
RESULTS From the data collected, the mean elapsed time from a ten percent electrical response in Group 1 (intralingual without massage) was 265 + 62.5 seconds
injection to
(Table 1). In this group, depression to ten percent remaining electrical activity was never achieved in two of the five children. With Group 2 (intralingual with massage) the mean time to 90% twitch depression was 133 ± 11.9 seconds with all participants in this group reaching the desired level of twitch depression. The use of the quadriceps femoris muscle in Group 3 resulted in a mean time to 90% depression calculated at 295 ± 42.6 seconds. Again, failure to reach 90% twitch reduction was recorded in three of five patients from this group. Using this particular method of measuring electrical depression, the patients in Groups 1 and 3 showed a similar time period before 90% depression was reached from IM injection alone, where the Group 2 patients exhibited the most consistent results and a shorter time period from baseline to a ten percent electrical activity. Throughout the succinylcholine post-injection period there were no arrhythmias noted with EKG monitoring. All patients in this study were successfully intubated using this method, and there were no clinical signs of any upper airway compromise after the submental administration of muscle relaxants as all patients were examined during intubation with direct visual laryngoscopy.
DISCUSSION
Laryngospasms are an unforgettable and preventable, yet treatable episode experienced by virtually everyone who has administered pediatric general anesthesia. Defined by Fink1 as a prolonged glottic closure maintained beyond the initiating stimuli, laryngospasm is a protective autonomic reflex resulting in complete or partial spasmodic closure of the vocal cords. It is generally heralded by the recognizable signs of airway obstruction-inspiratory stridor or complete absence of any audible signs of air movement, thoraco-abdominal or "rocking horse" breathing, and the inability to ventilate the patient resulting in the oxyhemoglobin desaturation seen during pulse oximetry. The types of stimulation leading to laryngospasm include small amounts of blood or secretions, foreign bodies in the laryngeal region, irritating inhalation agents, pain, light anesthesia, and even neck traction or manipulation sometimes seen during attempts to thrust the jaw forward. Regardless of the cause, treatment must be systematic and immediate. When laryngospasm occurs during induction, the pharynx should be suctioned followed by continuous positive pressure delivery with 100% oxygen. Deepening the anesthesia with an inhalation agent is also recommended in an effort to reverse vocal cord hyperactivity. Most spasms can be broken by this combination alone with adequate return of ventilatory volumes and proper oxygenation provided. But if laryngospasm persists and the threat of hypoxia develops, then the administration of
Anesth Prog 37:296-300 1990
298 Administration of Succinylcholine in Children
Table 1. Summary of demographic characteristics and time to maximal twitch depression. Intralingual Without Massage-(Group 1)
Subject # 1 2 3 4 5 MEAN ± SEM (n = 5)
Weight (Kg) 15.0 16.0 13.0 18.5 16.0 15.7 ± 0.89
Age (Years) 7.3 4.0 2.5 3.2 3.5 4.1 ± 0.84
Time to Maximum Twitch Depression (Sec.) 237 142 126 382* 436* 265 ± 62.5
Intralingual With Massage-(Group 2)
Subject # 1 2 3 4 5 MEAN ± SEM (n =5)
Weight (Kg) 16.0 19.0 12.5 17.0 15.0 15.9 ± 1.1
Age (Years) 3.0 7.2 3.5 3.8 2.3 4.0 ± 0.85
Time To Maximum Twitch Depression (Sec.) 120 114 168 109 155 133 ± 11.9
Upper Leg: Quadriceps Femoris-(Group 3)
Subject #
Age (Years) 3.9 3.5 5.3 2.3 6.2 4.2 ± 0.68
Weight (Kg)
1 2 3 4 5 MEAN ± SEM (n = 5) * Failed to reach twitch depression greater than 90% reduction from baseline
succinylcholine is recommended to allow the anesthesiologist total control of the airway. Currently, the recommeded dose of intramuscularly administered succinylcholine in children ranges from 1.5-4.0 mg/kg with varying reported effects.2 In this study, the injection of a 2% succinylcholine at a dose of 3.0 mg/kg either intralingually or using upper leg musculature resulted in satisfactory intubating conditions in all patients. None showed significant cardiovascular changes or airway obstruction lingually, which contradicts Masse and Dunbar's observations3 in which the administration of the drug transorally into the tongue resulted in a 28 percent incidence of arrhythmias in children anesthetized with halothane and nitrous oxide. Some patients in their study developed arrhythmias after a second does of succinylcholine was administered which may explain some of the differences from our findings. Also absent during our study
19 16 33 12 21
20.2 ± 3.5
Time To Maximum Twitch Depression (Sec.) 400* 291 360* 152 270* 295 ± 42.6
were signs of pulmonary edema, which has been casually related to the use of intramuscular succinylcholine.4 Fulminant pulmonary edema has been reported in infants 3 to 8 weeks of age associated with intramuscular succinylcholine. Although the mechanism is unclear, the problems of gastric aspiration, sympathetic stimulation associated with transient systemic and pulmonary hypertension, and the in vitro relaxation of pulmonary veins by parasympathetic stimulation have all been implicated. Based on our electromyographic study, the non-massaged intralingual injection of succinylcholine produced a similar rate of neuromuscular twitch depression and consequent succinylcholine absorption at 265 + 62.5 seconds when compared to the intramuscular injections into upper leg musculature as reported by Sutherland and Beven with 240 ± 36 seconds respectively.5 The data in our study also show that the submental intralingual site of
Redden et al. 299
Anesth Prog 37:296-300 1990
administration results in an equal or better recorded onset time in comparison with the quadriceps femoris site tested. Although this onset time may be considered too long for emergency situations,5 an important consideration in treating laryngospasms form clinical experience with intramuscular succinylcholine in children has been that airway control after laryngospasm is achieved in less time than the time to maximum twitch depression.2 In other words, less than 100% depression of twitch response may be sufficient to perceive the benefits toward regaining control of the airway. In terms of technique, the submental approach offers certain advantages to other intramuscular sites. By eliminating the need to remove any clothing to expose the muscular site, this area is easily assessable and is included in the visual field of the anesthesiologist. While the intraoral type of intralingual injections have been advocated for the administration of succinylcholine, the extraoral submental approach may also eliminate serious potential problems. With the extraoral approach, a full face mask can be continually maintained and the airway supported which is especially important when oxygen delivery and positive pressure is paramount. In children where the functional residual capacity is less than that of an adult, hypoxia can rapidly follow even a brief period of hypoventilation, or obstructive laryngospasm, with bradycardia from vagal stimulation often contributing to the problem. Hypoxia presents a serious threat of permanent neurological damage and may also cause prodromal cardiac arrhythmias (i.e., PVC's) prior to bradycardia and cardiac arrest. An important physiological principle to remember in children is that the cardiac rate is the more influential determinant of cardiac output, 40% of which contributes to pediatric cerebral blood flow.7 This rate dependency in the child is largely due to the fact that changes in myocardial contractility (stroke volume) cannot compensate effectively in the child's heart when compared to the adult in maintaining the cardiac output. Because parasympathetic tone is most pronounced in infancy until at least 1 year of age with variable degrees of increased parasympathetic tone in earlier years of childhood, a decrease in cardiac rate due to vagal stimulation can also result in decreased cardiac output and hypotension. This type of stimulation frequently occurs with manipulation of the airway including endotracheal intubation.7 For this reason, it is often recommended that children be premedicated with a parasympathetic blocking drug such as atropine or glycopyrollate to oppose these predictable changes in heart rate. Additionally, with an extraoral injection there is a decreased chance of bleeding into the airway which can only potentiate a hyper-reflexic glottis and could go unnoticed for an undetermined amount of time. This technique may also be anatomically safer by avoiding potential airway
obstruction from a swollen tongue, or possible damage to associated oral structures including Wharton's Duct and the lingual nerve. Furthermore, there is a trend in this study which suggests that digital massage of the submental area following injection may lead to a more rapid and consistent level of muscular paralysis when compared to other peripheral injection sites, or even the submental area with no massage. Peripheral vasoconstriction in children resulting from extreme anxiety or a cold environment is common and can decrease the absorption of intramuscularly administered drugs. The end result is usually a delayed onset of action and lower plasma levels of injected drugs. Interestingly enough, massaging the submental injection site of Group 2 resulted in a decreased mean twitch depression time of 133 + 11.9 seconds. This simple routine reduced the effective time of an IM injection by approximately 50 percent according to this data. Without massage of either the submental or upper leg musculative sites, inconsistent levels of neuromuscular paralysis resulted with 5 of 10 patients in Groups 1 and 3 never reaching 90 percent twitch reduction. The massaged Group 2 also had a greater success rate achieving the desired depression level suggesting that digital massage not only decreases the maximum twitch depression time, but increases the efficacy of the muscle relaxing agent. Some massage is inadvertently performed to a certain extent via the anesthesiologist's hand placement over the full face mask and under the patient's mandible during "chin-up" head extension and mask adaptation for airway maintenance. In conclusion, the availability and effectiveness of the injection site and the ability of a single operator to alone provide airway maintenance, administer intramuscular succinylcholine, and perform digital massage supports the usefulness of the submental approach. And though the advantages of massage in a group using the upper leg musculature was not proven in this study, those reluctant to use the submental route may find that massage of the vastas lateralis or quadriceps femoris may prove to be more than just a kind gesture to a sore muscle.
REFERENCES 1. Fink BR. The Human Larynx: A Functional Study. Raven Press, New York, 1975:100. 2. Lui L. Dose Response to Intramuscular Succinylcholine in Children. Anesth 1981;55:599-602. 3. Mazee RI, Dunbar RW. Intralingual Succinylcholine Administration in Children. Anesth Analg 1968;47:605-615. 4. Cook DR. Pulmonary Edema in Infants: Possible Association with Intramuscular Succinylcholine. Anesth Analg 1981;60:220-223.
300 Administration of Succinylcholine in Children 5. Sutherland GA, Beven JC. Neuromuscular Blockade in Infants Following Intramuscular Succinylcholine in Two or Five Percent Concentrations. Can Anesth Soc J 1983;30:342346.
Anesth Prog 37:296-300 1990 6. Campbell RL. General Anesthesia for the Pediatric Patient. J Oral Maxillofac Surg 1982;40:497-506. 7. Anderson J. Pediatric Denistry: Infancy Through Adolescence. W. B. Saunders Company-Philadelphia, 1988:67-72.
