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Second, the degree of relief afforded by the study drug was compared with the degree of relief in those receiving placebo using a numerical pain scale. These rank-order, ordinal data m a y have been more appropriately tested using nonp a r a m e t r i c m e t h o d s , as Drs DeBehnke and McKee have pointed out. Differences in null hypothesis probabilities between parametric and nonp a r a m e t r i c m e t h o d s are u s u a l l y slight, but I will concede that this can assume importance when results are of borderline significance. Our results were not borderline. To clear up any doubt about our c o n c l u s i o n s that m a y result f r o m this, we reanalyzed our ordinal data using the M a n n - W h i t n e y U test. 2 (The Wilcoxon test was not appropriate because the samples were independent.) As expected, the difference in pain relief between the placebo and metoclopramide group was significant (P = .02). Finally, Dr DeBehnke recommends comparing a new treatment against a "gold standard." He is right that no s u c h gold s t a n d a r d exists in migraine. As explained in the article, that is one of the reasons we undertook this study. He suggests testing m e t o c l o p r a m i d e versus meperidine or DHE. While such studies might be interesting, they would be problematic. T h e e u p h o r i a p r o d u c e d by meperidine would be difficult to separate from pure pain relief and could bias the subjects. A comparison with a non-~ agonist analgesic such as nalbuphine would be more revealing, and we would welcome such a study. The use of DHE requires s i m u l taneous use of a dopamirie antagonist (often metoclopramide) to reduce the adverse side effects of the drug, rendering a meaningful comparison impossible. T e s t i n g DHE as a single agent would not be relevant to clinical p r a c t i c e . T h e q u e s t i o n t h a t we w a n t e d to a n s w e r was w h e t h e r metoclopramide really relieved migraine cephalgia. The double-blind, placebo-controlled clinical trial was the most reliable means of answering that question. I believe most of your readers would agree. 176/712

I thank Drs DeBehnke and McKee for giving us the opportunity to clarify these issues and to restate our conclusion: that metoclopramide is effective and safe therapy as a single agent for acute episodes of migraine. Deniz S Tek, MD, FACEP Emergency Department Saint Vincent Hospital Billings, Montana 1. Caddis GM, Gaddis ML: Introduction to biostatistics: Part 5, Statistical inference techniques for hypothesis testing with nonparametric data. Ann Emerg Med 1990;19:1054-1059. 2. SPSS/PC+. version 2.1. SPSS Inc, Chicago, 1989.

The MANTRELS

Score

To the Editor." Bond et al are to be applauded for their contribution of examining the p e r f o r m a n c e of Alvarado's appendicitis scoring system in a prospective trial on children in "Use of the MANTRELS Score in Childhood Appendicitis: A Prospective Study of 187 Children With Abdominal Pain" [September 1990;19:1014-1018]. Their findings of the system's poor perform a n c e in the younger age groups (Table 3) document the few clinical differences between children with and without appendicitis. It confirms the difficulty in diagnosing appendicitis in children. It explains why the perforation rate was so high in this (60%) and past studies On children with abdominal pain. Unfortunately, their data do not support their conclusion that clinical judgment outperforms the scoring system. Calculating confidence intervals for their results, 1 clinical judgm e n t and the scoring s y s t e m had equal performance in the initial evaluation of patients in the emergency department. One hundred forty-three patients were judged by the emergency physicians to need hospitalization for appendicitis, a false-positive rate of 19% (95% CI 13,27) and sensitivity of 99% (95% CI 95,100'). This is similar to the score's performance. At a cutoff score of 6, the MANTRELS s y s t e m had a false-positive surgery rate of 24% (95% CI 17,32) and s e n s i t i v i t y of 95% (95% CI Annals of Emergency Medicine

89,97). There is no statistically significant difference between the physician's performance and the scoring system's performance. Another failure in the analysis was comparing the scoring system's preo b s e r v a t i o n p e r f o r m a n c e w i t h the clinician's p o s t o b s e r v a t i o n performance. The patient's postobservation appendicitis scores (scores at the time the clinicians made a final decision on surgery or discharge of the patient) would have been very different from the patient's initial scores. During observation we have found that the appendicitis patients' scores worsen and the nonappendicitis patients' scores improve. 2 Clearly, Bond examined physician performance after observation. In the study, 20 of the 143 admitted patients had an evaluation in the hospital after which they did not go to surgery, and these were counted as truenegative physician decisions. This is consistent with past research that has shown that physician diagnostic performance is improved by a short period of observation of the abdominal pain patient being evaluated for appendicitis. This occurs because the clinician recognizes changes in clinical condition during observation (appendicitis p a t i e n t s get worse and nonappendicitis patients improve) 3 and does further diagnostic tests (ult r a s o u n d , b a r i u m e n e m a , laparoscopy). 4 Before the MANTRELS scoring system is abandoned, further study should examine MANTRELS scores in children after observation. This study underscores the need for physicians to improve their diagnostic performance in evaluating children for appendicitis (60% perforation rate in this study). Physicians are at least partially responsible for the delay in diagnosis, s and an aid such as A1varado's scoring system is needed. Louis Graft, MD, FACEP, FACP Emergency Department N e w Britain Hospital N e w Britain, Connecticut 1. Pearson ES, Hartley BO: Biometrika TabIes for Statisticians, voI 1. Cambridge, Cambridge University Press, t954, table 41. 2. Graft LG, Radford M, Werne C: Probability of appendicitis before and after observation (abstract). A n n

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Emerg Med 1989;18:439. 3. Nauta RJ, Magnant C: Observation versus operation for abdominal pain in the right lower quadrant. Am J Surg 1986;15h746-748. 4. White JJ, Santillana M, Haller JA: Intensive in-hospital observation: A safe way to decrease unnecessary appendectomy. Am Surg 1975;41:793-799. 5. Brender ID, et ah Childhood appendicitis: Factors associated with perforation. Pediatrics 1985~76:301-306.

fn Reply: Dr Graft is comparing admission decision apples to our operative decision oranges. Both are potential uses of a clinical score, but we o n l y sought to test the ability of the score to make an early, accurate, operative decision avoiding in-hospital delay and potential associated morbidity. Our use of eventual outcome is the only appropriate gold standard for evaluating this usage. Physicians rarely need help deciding that a child with a rigid abdomen requires operative i n t e r v e n t i o n or that a smiling, jumping child may go home. They need help sorting out children in between. This has traditionally been done by serial observation. To be advantageous, a score m u s t offer one of three improved outcomes: 1} better triage (fewer unnecessary admissions without loss of sensitivity}; 2} better initial screening (earlier, equally accurate decision to operate); or 3} more accurate ultimate decision making (fewer falsepositive surgeries without a loss of sensitivity). Although it was not the focus of our study, Dr Graft uses our data to point out that the MANTRELS score offers no advantage over physician triage in the group of all children. Used for thi's purpose, however, a MANTRELS score of 6 would have resulted in six of 88 children less than 16 years old with appendicitis being sent home from the emergency department (sensitivity, 93%). We sought to test the score's ability to offer better initial screening. We demonstrated that no single score at the time of ED evaluation could have saved observation time in some of the children w i t h o u t subjecting many to unnecessary surgery. Obviously, all children admitted but not operated on underwent serial obser20:6:June1991

vation. Because we did not collect data regarding the time from initial evaluation to the decision to operate, we cannot say how many of our operative group underwent serial observation. This represents another potential use of the score that we did not seek to test. As Dr Graft points out, "appendicitis patients get worse and nonappendicitis patients improve." It is difficult to see much advantage in serial scoring over serial physician examination alone, but the theoretical potential for greater speed to decision or more accurate decision exists and is so far untested. Considering ultimate accuracy, our physicians outperformed the MANTRELS score even at scores associated with unacceptably low levels of sensitivity. How much of that accuracy was the result of serial observation offering the theoretical potential for improvement by serial scoring is unknown. Although delay from symptom onset to operative intervention results in an increased rate of perforation, three time periods contribute to this delay - the time from symptom onset to presentation, the time from presentation to diagnosis, and the time from diagnosis to operative intervention. In our series, the first period was frequently more than 24 hours. This is the most significant factor in our high perforation rate. In many crowded inner-city hospitals with o v e r w o r k e d surgical services, the second and third periods are also prolonged. As emergency physicians we have the opportunity to influence only the second period. We should continue to examine all diagnostic options that offer the potential to do this. We remain unconvinced that the MANTRELS score offers a diagnostic advantage in children. Early surgical consultation remains the most effective way to reduce the delay from presentation to diagnosis.

G Randall Bond, MD Susan B Tully, MD Linda S Chan, PhD Department of Pediatrics University of Virginia Charlottesville Annals of Emergency Medicine

Sedation for Pediatric Laceration Repair To the Editor." The articles "The Effect of Oral Midazolam on Anxiety of Preschool Children During Laceration Repair" by H e r m e s et al [ S e p t e m b e r 1990;19:1006-1009] and "Ketamine Sedation for Pediatric Procedures" by Green et al [September 1990;19: 1024-1032] reflect a growing interest in pediatric pain control and the recent focus on minimizing the fear, anxiety, and discomfort our youngest patients may experience while undergoing m i n o r procedures in the emergency department. Pain control and alleviation of anxiety are certainly worthy goals. However, we are concerned that the trend toward the use of agents such as midazolam and ketamine for minor procedures, despite the demonstration of their apparent safety and efficacy, may reflect a tendency to consider the physician's comfort and time above the best interests of the patient. We concede the fact that there are some injuries and procedures that by their very nature make local anesthesia impractical or impossible. In this category we would place cleaning and debridement of extensive abrasions (so-called "road-burn"), joint aspirations, extensive or complicated lacerations, and the pelvic examination in an abuse situation. There are certainly other procedures and situations that would fall into this class. We would not place the simple laceration requiring fewer than a dozen sutures in this category of injury. Most m i n o r l a c e r a t i o n s can be dealt with very effectively and, for the most part, very efficiently with local infiltration of lidocaine or topical application of TAC 1 or LAC (lidocaine, adrenaline, cocaine}. The most important factor in the effective use of lidocaine is correct infiltration technique. ~ The proper infiltration of lidocaine takes time and patience on the part of the physician. Meticulous attention to slow infiltration renders the process virtually pain free. Buffering the lidocaine with sodium bicarbonate may further enhance pain reduction. 3 713/177