416 TABLE Riskgroups for atlanto-axialsubluxation Pathological states Ankylosing spondylitis* Enteropathic arthritis Infections (especially pharyngeal) Postoperative (especially ENT) Psoriatic arthritis Reiter's syndrome Rheumatoid arthritis (adult and juvenile)* Systemic lupus erythematosus trauma (especially in young children)* Tumour* Congenital conditions Congenital scoliosis* Disproportionate dwarfism (but not achondroplasia)* Down syndrome* Mucopolysaccharidoses* Neurofibromatosis Osteogenesis imperfecta Scott syndrome* Vertebral anomalies (cervical)*
CANADIAN JOURNAL OF ANAESTHESIA
should be reviewed by a radiologist infornaed of the diagnosis and of the concerns. Evaluation and management of the patient at risk for cervical spine instability is a critical consideration for the anaesthetist. This is not limited to the trauma patient. Upper respiratory pathology, surgery in the pharyngeal area, and a host of congenital and acquired conditions are risk factors for cervical instability. Knowledge of who is at risk and the taking of appropriate precautions are important aspects of safe anaesthetic practice. *Steve M. Audenaert MD i'Thomas E. Schmidt MD *Departments of Anesthesiology and Pediatrics tUniversity of Kentucky Medical Center and Shriner's Hospital for Crippled Children, Lexington, Kentucky 40536. REFERENCES
1 Crosby ET, Lui A. The adult cervical spine: implicaAll of these groups are at risk for atlanto-axial subluxation. Risk arises from ligamentous laxity, odontoid hypoplasia, loss of mobility elsewhere in the cervical spine, degeneration or abnormality of bony supports, or from a combination of these factors. *Group where routine preoperative radiographic screening appears warranted.
Grisel described non-traumatic atlanto-axial subluxation associated with pharyngeal disease in 1930. 2 This entity commonly presents with torticollis or neck pain, sometimes with neurological symptoms, and has been reported after a long list of surgical procedures including mastoidectomy, tonsillectomy, and adenoidectomy. 3 Any patient with an inflammatory process in the pharyngeal area (tumours as well as infection 5) is at risk for atlanto-axial subluxation. Extra caution needs to be urged in accepting the x-ray diagnosis of a stable cervical spine in paediatric trauma. Fracture of the odontoid is more common in children than in adults, and radiographic interpretation is more difficult. 6'7 Paediatric victims of serious trauma should be assumed to have an unstable spine even after being "cleared" and caution is advised before airway manipulation and in patient positioning. We agree with Crosby and Lui's recommendation to obtain cervical spine x-rays as part of the preoperative evaluation of patients at high risk for cervical spine instability. We would include not only patients with Down's Syndrome or rheumatoid arthritis, but also other patient groups at high risk for atlanto-axial subluxation (see Table). The cervical spine series must include odontoid, extension, and non-forced flexion views, and
2 3
4 5
6
tions for airway management. Can J Anaesth 1990; 37: 77-93. Grisel P. Enucleation de I'atlas et torticolis nasopharyngien. Presse Med 1930; 38: 50-4. Wilson BC, Jarvis BL, Haydon RC. Nontraumatic subluxation of the atlantoaxial joint: Grisel's syndrome. Ann Otol Rhinol Laryngol 1987: 96: 705-8. Wetzel FT, LaRocca H. Grisel's Syndrome: A review. Clin Orthop 1989; 240: 141-52. Parker DA, Seb~yn P, Bradley PJ. Subluxation of the atlanto-axial joint. Br J Oral Maxillofac Surg 1985; 23: 275-8. Diekema DS, Allen DB. Odontoid fracture in child occupying a child restraint seat. Pediatrics 1988; 82: 117-9.
7 Fuchs S, Barthel MJ, Flannery AM, Christoffel KK.
Cervical spine fractures sustained by young children in forward-facing car seats. Pediatrics 1989: 84: 348-54.
But what do nonparametric data mean? To the Editor: There have been many publications on the need for higher standards of statistical excellence in anaesthesia and medical journals. ~-31 have noted an error in the statistical methods of two publications in the September issue of the Canadian Journal of Anaesthesia. 4'5 Those authors stated
CORRESPONDENCE
"... Chi-square analysis on nonparametric data ..."4 and "... the Kruskal-Wallis test for nonparametric data ''5 respectively in their papers. I would like to point out that nonparametric data do not exist, but there are nonparametric statistics. Strictly speaking, only those procedures that test hypotheses that are not statements about population parameters are classified as nonparametric. 6 Mohamed Naguib MB BCh MSc FFARCSI Department of Emergency and Critical Care Medicine Faculty of Medicine & Health Sciences United Arab Emirates University Box 17666, AI Ain United Arab Emirates REFERENCES
I Wallenstein S, Zucker CL, Fleiss JL. Some statistical
2
3
4
5
6
methods useful in circulation research. Circ Res 1980; 47: I-9. Airman DG, Gore SM, Gardner MJ, Pocock SJ. Statistical guidelines for contributors to medical journals. BMJ 1983; 286: 1489-93. Bailar JC, Mosteller F. Guidelines for statistical reporting in articles for medical journals. Amplifications and cxplanations. Ann Int Med 1988; 108: 266-73. Fuller JG, McMorland GH, Douglas MJ, Palmer L. Epidural morphine for analgesia after Caesarean section: a report of 488 patients. Can J Anaesth 1990; 37: 636-40. Maltby JR, Elliott RH, Warnell I et al. Gastric fluid volume and pH in elective surgical patients: triple prophylaxies is not superior to ranitidinc alone. Can J Anaesth 1990; 37: 650-5. Daniel WW. Biostatistics: a foundation for analysis in health sciences. 3rd Ed. New York: John Wiley & Sons, 1983; 388-435.
Lidoca?ne en a rosol aprEs l'amygdalectomie chez l'enfant To the Editor: l would like to support the concept reported in Dr. Bissonette's paper on the use of lidocaine aerosol following tonsillectomy. Much of the misery following tonsillectomy is caused by the pain which occurs with swallowing due to the raw tonsilfossa. The application of local anaesthesia to the raw areas relieves the pain and allows the child to swallow more easily.
417
About 20 yr ago 1 undertook a study where l put local anaesthetic on the pack placed in the tonsil fossa. Many children gained substantial relief but there were some failures. ! then decided that spraying the fossa with local anaesthetic directly would be more effective. Since the advent of bupivacaine I have used an 0.5% solution drawn up in a 2 ml syringe and injected through a needle with the tip bent to a right angle. This splits the flow on injection so that it acts as a spray making access to the upper and lower poles easier. Small fossae need about 0.5 ml on each side while large ones need about I ml per side to give a complete coating of the raw surface. The surgeon sucks away any local anaesthesia that spills on the posterior pharynx and any excess in the fossa after the bupivacaine has had about half a minute to absorb on to the tissues. Another altemative providing the same benefit is the injection of local anaesthetic prior to surgery. If placed in the correct plane it will also facilitate the dissection of the tonsil. Bupivacaine provides a longer effect than lignocaine. The other advantages of the method are the decrease in opiate requirements which reduces the incidence of respiratory obstruction or depression which can end in tragedy when excessive doses are used and much more peaceful patients in the recovery room. T.C.K. Brown Director of anaesthesia Royal Children's Hospital Melbourne, Australia
REPLY ! would offer the following comments. First, I think that if one decides to use local anaesthetic as a postoperative analgesic technique one should be aware of the possible complications. lntracarotid injection has been reported after infiltration of local anaesthetics into the tonsillar beds. As Dr. Brown has observed after application of local anaesthetic to the tonsillar area, aspiration of the excess of local anaesthetic is mandatory. Application of drugs onto freshly traumatised and oozing membrane raises the problem of .~ystemic absorption to toxic levels. As reported in my paper, 4 rag. kg -t lidocaine spray divided evenly on each tonsillar bed did not reach a toxic level, t Second, ! have been reluctant to use bupivacaine in the tonsillarfossae for analgesia. Although the use of bupivacaine is very attractive because of its longer duration of action and potency, it has been reported that bupiwmaine cardiore.wiratoO, toxicity is more likely when the agent is combined with epinephrine or phenylephrine.3 Vasoconstrictors are commonly used during tonsillectomy. The cardiac index was depressed and asystole occurred at a lower dose of bupivacaine in young pigs when they were receiving halothane or isoflurane/ It was concluded that N20 plus halothane or 3120 plus isoflurane increased the mortality of bupivacaine while they obscured the early warning signs of toxicity. Finally, if bupivacaine is
CANADIAN JOURNAL OF ANAESTHESIA
should be reviewed by a radiologist infornaed of the diagnosis and of the concerns. Evaluation and management of the patient at risk for cervical spine instability is a critical consideration for the anaesthetist. This is not limited to the trauma patient. Upper respiratory pathology, surgery in the pharyngeal area, and a host of congenital and acquired conditions are risk factors for cervical instability. Knowledge of who is at risk and the taking of appropriate precautions are important aspects of safe anaesthetic practice. *Steve M. Audenaert MD i'Thomas E. Schmidt MD *Departments of Anesthesiology and Pediatrics tUniversity of Kentucky Medical Center and Shriner's Hospital for Crippled Children, Lexington, Kentucky 40536. REFERENCES
1 Crosby ET, Lui A. The adult cervical spine: implicaAll of these groups are at risk for atlanto-axial subluxation. Risk arises from ligamentous laxity, odontoid hypoplasia, loss of mobility elsewhere in the cervical spine, degeneration or abnormality of bony supports, or from a combination of these factors. *Group where routine preoperative radiographic screening appears warranted.
Grisel described non-traumatic atlanto-axial subluxation associated with pharyngeal disease in 1930. 2 This entity commonly presents with torticollis or neck pain, sometimes with neurological symptoms, and has been reported after a long list of surgical procedures including mastoidectomy, tonsillectomy, and adenoidectomy. 3 Any patient with an inflammatory process in the pharyngeal area (tumours as well as infection 5) is at risk for atlanto-axial subluxation. Extra caution needs to be urged in accepting the x-ray diagnosis of a stable cervical spine in paediatric trauma. Fracture of the odontoid is more common in children than in adults, and radiographic interpretation is more difficult. 6'7 Paediatric victims of serious trauma should be assumed to have an unstable spine even after being "cleared" and caution is advised before airway manipulation and in patient positioning. We agree with Crosby and Lui's recommendation to obtain cervical spine x-rays as part of the preoperative evaluation of patients at high risk for cervical spine instability. We would include not only patients with Down's Syndrome or rheumatoid arthritis, but also other patient groups at high risk for atlanto-axial subluxation (see Table). The cervical spine series must include odontoid, extension, and non-forced flexion views, and
2 3
4 5
6
tions for airway management. Can J Anaesth 1990; 37: 77-93. Grisel P. Enucleation de I'atlas et torticolis nasopharyngien. Presse Med 1930; 38: 50-4. Wilson BC, Jarvis BL, Haydon RC. Nontraumatic subluxation of the atlantoaxial joint: Grisel's syndrome. Ann Otol Rhinol Laryngol 1987: 96: 705-8. Wetzel FT, LaRocca H. Grisel's Syndrome: A review. Clin Orthop 1989; 240: 141-52. Parker DA, Seb~yn P, Bradley PJ. Subluxation of the atlanto-axial joint. Br J Oral Maxillofac Surg 1985; 23: 275-8. Diekema DS, Allen DB. Odontoid fracture in child occupying a child restraint seat. Pediatrics 1988; 82: 117-9.
7 Fuchs S, Barthel MJ, Flannery AM, Christoffel KK.
Cervical spine fractures sustained by young children in forward-facing car seats. Pediatrics 1989: 84: 348-54.
But what do nonparametric data mean? To the Editor: There have been many publications on the need for higher standards of statistical excellence in anaesthesia and medical journals. ~-31 have noted an error in the statistical methods of two publications in the September issue of the Canadian Journal of Anaesthesia. 4'5 Those authors stated
CORRESPONDENCE
"... Chi-square analysis on nonparametric data ..."4 and "... the Kruskal-Wallis test for nonparametric data ''5 respectively in their papers. I would like to point out that nonparametric data do not exist, but there are nonparametric statistics. Strictly speaking, only those procedures that test hypotheses that are not statements about population parameters are classified as nonparametric. 6 Mohamed Naguib MB BCh MSc FFARCSI Department of Emergency and Critical Care Medicine Faculty of Medicine & Health Sciences United Arab Emirates University Box 17666, AI Ain United Arab Emirates REFERENCES
I Wallenstein S, Zucker CL, Fleiss JL. Some statistical
2
3
4
5
6
methods useful in circulation research. Circ Res 1980; 47: I-9. Airman DG, Gore SM, Gardner MJ, Pocock SJ. Statistical guidelines for contributors to medical journals. BMJ 1983; 286: 1489-93. Bailar JC, Mosteller F. Guidelines for statistical reporting in articles for medical journals. Amplifications and cxplanations. Ann Int Med 1988; 108: 266-73. Fuller JG, McMorland GH, Douglas MJ, Palmer L. Epidural morphine for analgesia after Caesarean section: a report of 488 patients. Can J Anaesth 1990; 37: 636-40. Maltby JR, Elliott RH, Warnell I et al. Gastric fluid volume and pH in elective surgical patients: triple prophylaxies is not superior to ranitidinc alone. Can J Anaesth 1990; 37: 650-5. Daniel WW. Biostatistics: a foundation for analysis in health sciences. 3rd Ed. New York: John Wiley & Sons, 1983; 388-435.
Lidoca?ne en a rosol aprEs l'amygdalectomie chez l'enfant To the Editor: l would like to support the concept reported in Dr. Bissonette's paper on the use of lidocaine aerosol following tonsillectomy. Much of the misery following tonsillectomy is caused by the pain which occurs with swallowing due to the raw tonsilfossa. The application of local anaesthesia to the raw areas relieves the pain and allows the child to swallow more easily.
417
About 20 yr ago 1 undertook a study where l put local anaesthetic on the pack placed in the tonsil fossa. Many children gained substantial relief but there were some failures. ! then decided that spraying the fossa with local anaesthetic directly would be more effective. Since the advent of bupivacaine I have used an 0.5% solution drawn up in a 2 ml syringe and injected through a needle with the tip bent to a right angle. This splits the flow on injection so that it acts as a spray making access to the upper and lower poles easier. Small fossae need about 0.5 ml on each side while large ones need about I ml per side to give a complete coating of the raw surface. The surgeon sucks away any local anaesthesia that spills on the posterior pharynx and any excess in the fossa after the bupivacaine has had about half a minute to absorb on to the tissues. Another altemative providing the same benefit is the injection of local anaesthetic prior to surgery. If placed in the correct plane it will also facilitate the dissection of the tonsil. Bupivacaine provides a longer effect than lignocaine. The other advantages of the method are the decrease in opiate requirements which reduces the incidence of respiratory obstruction or depression which can end in tragedy when excessive doses are used and much more peaceful patients in the recovery room. T.C.K. Brown Director of anaesthesia Royal Children's Hospital Melbourne, Australia
REPLY ! would offer the following comments. First, I think that if one decides to use local anaesthetic as a postoperative analgesic technique one should be aware of the possible complications. lntracarotid injection has been reported after infiltration of local anaesthetics into the tonsillar beds. As Dr. Brown has observed after application of local anaesthetic to the tonsillar area, aspiration of the excess of local anaesthetic is mandatory. Application of drugs onto freshly traumatised and oozing membrane raises the problem of .~ystemic absorption to toxic levels. As reported in my paper, 4 rag. kg -t lidocaine spray divided evenly on each tonsillar bed did not reach a toxic level, t Second, ! have been reluctant to use bupivacaine in the tonsillarfossae for analgesia. Although the use of bupivacaine is very attractive because of its longer duration of action and potency, it has been reported that bupiwmaine cardiore.wiratoO, toxicity is more likely when the agent is combined with epinephrine or phenylephrine.3 Vasoconstrictors are commonly used during tonsillectomy. The cardiac index was depressed and asystole occurred at a lower dose of bupivacaine in young pigs when they were receiving halothane or isoflurane/ It was concluded that N20 plus halothane or 3120 plus isoflurane increased the mortality of bupivacaine while they obscured the early warning signs of toxicity. Finally, if bupivacaine is
