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

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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.

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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

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sprayed at the end of tonsillectomy while the patient is breathing spontaneously, one sho,dd be aware that apnoea, one of the major signs of bupivacaine toxicity, ahvays precedes cardiovascular collapse/ I agree with Dr. Brown that bupivacaine may become the agent of choice for longer and more satifactory posttonsillectomy analgesia. However, I believe that further investigation of the safety and recommended dosage is required before we can support its general use. REFERENCES

1 Bissonnette, B. Lidocaine en a6rosol apr/~s I'amygdalectomie chez I'enfant. Can J Anaesth 1990; 37: 534-7. 2 Kambam JR, Wesley WK, Matsuda F, Wright W, Duncan AH. Epinephrine and phenylcphrinc increase cardiorespiratory toxicity of intravenously administered bupivacaine in rats. Anesth Analg 1990; 70: 543-5. 3 BadgwellJM, Heavner JE, Kytta JH. Bupivacaine toxicity in young pigs is age-dependent and is affected by volatile anesthetics. Anesthesiology 1990; 73:297-303 4 Lina AA, Dauchot PJ, Anton AH, Jezeski BS. Immediate ventilatory support after bupivacaine-induced apnea prevents CV collapse in anesthetized rats. Anesthesiology 1990; 73: A845. Bruno Bissonnette Mo FREPC The Hospital for Sick Children Toronto

Anaesthesia high-risk nurse To the Editor: In these demanding times it is difficult to understand why, as a group, we have chosen to disregard an opportunity for a cost-effective, efficient means of improving patient care and support for our role as anaesthetists. By unequivocally accepting the concept of an anaesthesia technician, the CAS Council (February 1990) endorsed a choice but not an optimal solution. In providing care to high-risk surgical patients, the composition of the anaesthesia care team (ACT) is crucial. We have identified the need for a nurse who provides a combination of patient management and technical support and a bridge between our patients' needs and our role as practitioners. In our institution, we have found that an anaesthesia high-risk nurse (AHRN) fulfils this vital role extremely well. This position is held by a registered nurse with an approved diploma from an intensive care nursing program with one to two years of clinical intensive care unit experience. In addition, the nurse receives one to two months of training on our Department's routines, protocols, etc. Without providing a full job description, let us outline some of the benefits of this position. First, it is costeffective and efficient. Training costs are manageable

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because the majority of the education has already been completed. In addition, both practitioner and patient benefit from the broad experience and technical skills already gained in the intensive care unit. The nurse's equipment and monitoring experience has improved the efficiency of our patient transfer. Her/his role as a liaison with recovery and intensive care staff has reduced system duplication. The AHRN is also a major participant in meeting the overall objectives of our Department. Product and cost evaluation; efficient use of various drug administration routines; participation with other allied units in an ongoing equipment and technical review; all play a contributing role in our Department's effective operation. More important, though, is the impact of this position on the management of our patients, especially those of the high-risk category. As a member of the team, the nurse's assessment capabilities, problem-solving skills and ability to intervene where necessary, further supports the anaesthetist's ability to provide quality care. The AHRN has drug administration experience and monitoring expertise that provide vital information on a given patient's progress. Her/his skills and experience enable proper dealing with the patient's emotional and physiological needs in the perioperative period. How often do anesthetists have the luxury of time, or the capacity to deal with many of these issues satisfactorily? In building a support team, the question becomes, Does the restrictive nature of a technical position, by definition, provide the answer? Does it increase our ability to provide better care? Perhaps. Does it help our patients? Not to the extent of the experience or capability of a well-trained AHRN. By adding a technician we may be adding more skill, but are we solving the problem'? Instead of debating whether the answer lies with a technician or a nurse, perhaps the optimum answer lies in addressing which "position" will enable us to do our job better. We strongly recommend that instead of accepting a unilateral approach of utilizing an anaesthesia assistant/ technologist that other approaches, such as the role outlined above, be considered. Peter Duke MD FRCPC Debbie Paterson RN Chris Kehler MD FRCPC Department of Anesthesia Health Sciences Centre University of Manitoba Winnipeg, Manitoba