CORRESPONDENCE Opinions expressed in the Correspondence Section are those of the authors, and not necessarily of the Journal editors, A CEP, or UA/EM.

Treatment of Phencyclidine Overdose

To the Editor:

I wish to echo the editorial comments of Barry Rumack, MD, regarding treatment of phencyclidine overdose (9:595, 1980). A major complication of the treatment of behavioral effects of phencyclidine over- dose is the consequence of over-treatment.1 Although phencyclidine appears to be the most commonly abused street drug, it is not always possible to tell if that is the drug or the only drug that a patient seen in the emergency department has used) ,2

Consequently acidifying, tranquilizing, or otherwise altering the patient's biochemical status may compli- cate recovery rather than hasten it. Because conserva- tive treatment Ca quiet, supportive environment") is successful most of the time, that should be the treat- ment of choice for the behavioral effects of PCP use unless further treatment is absolutely necessary. 1'3

Beverly J. Fauman, MD, Chief Division of Psychiatric Emergencies

Henry Ford Hospital Detroit

1. Fauman MA, Fauman BJ: Chronic PCP abuse: a psychiat- ric perspective. J Psyched Drugs 12:307-315, 1980. 2. Fauman B, Aldinger G, Fauman M, et al: Psychiatric se- quellae of phencyctidine abuse. Clin Toxicol 9:529-538, 1976. 3. Stein J: Phencyclidine induced psychosis. The need to avoid unnecessary sensory influx. Military Med 138:590-593, 1973.

Mechanical ECC Not Yet Warranted

To the Editor:

I wish to comment on the correspondence (9:47-48, 1980) on mechanical versus manual external ches t compression (ECC). The article 1 referred to by Mr. Peterson does not support his conclusion that the re- quired level of performance can be more easily ob- tained mechanically. In fact, that study found no sig- nificant differences between the two methods, either in complication rate or in outcome. Furthermore, pre- vious studies 2'3 have indicated that adequate perfor- mance on the Recording Annie is probably not a reli- able indicator of effective performance in patients, especially if immediate feedback in the form of an in- tra-arterial pressure curve or Doppler flowmeter is provided.

Dr. Nagel's point that further studies are required is important; since current studies have not shown a decided advantage to mechanical ECC in real patients, but only equivalence, the extensive application of an expensive device such as the Thumper ® is premature. The history of medicine is all too full of examples of

the premature introduction of therapeutic modalities which subsequently prove to be ineffective or even harmful. Unti l it can be shown by well-designed stud- ies that mechanical ECC leads to greater survival, fewer complications, or lower cost, its widespread ap- plication is unwarranted.

"I would like to be concerned not with what is new, but what is best." PIRSIG, Zen and the Art of Motorcycle Maintenance.

Robert L. Wears, MD Jacksonville, Florida

1. Taylor GJ, Rubin R, Tucker M, et al: External cardiac compression. JAMA 240:644-646, 1978. 2. Taylor GJ, Tucker WT, Greene HL, et al: Importance of prolonged compression during cardiopulmonary resuscitation in man. New Engl J Med 296:1515-1517, 1977. 3. Vaagenes P, Lund I, Skulbert A, et al: On the technique of external cardiac compression. Crit Care Med 6:176-180, 1978.

Treatment for "Immersion" Accidental Hypothermia To the Editor:

I enjoyed the article by Myers, Britten and Cow- ley entitled "Hypothermia: Quantitative Aspects of Therapy" (8:523-527, 1979), as it provided the formu- las and Calculations needed to assess the value of the different rewarming methods. I endorse their state- ment, "Mortality rates, rather than warming rates, should dictate choice of therapy."

The reason the reports extracted from the Dachau concentration camp 1 conflict with the many reports supporting passive rewarming 24 may be related to the onset of the hypothermia. In the German prison camp, prisoners were immersed in water of 2 C to 12 C and cooled rapidly. The pathophysiology associated with rapid cooling from this extremely cold environment is different from that experienced in an outdoorsman over many hours of exhaustive physical activity or an alcoholic sleeping outdoors on a cold night.

I suggest that for "immersion" accidental hypo- thermia rapid, external rewarming may be the treat- ment of choice, whereas slow, passive rewarming has fewer complications, such as rewarming shock, than do other methods of treating accidental hypothermia. 5

This is another controversial area of emergency medicine ripe for research analysis.

Charles M. Bova, MD Medical Director

New Mexico Emergency Medical Services Albuquerque

1. Alexander L: Item No. 24, File No. XXVI-37 (Combined Intelligence Objectives Subcommittee, US Army, July 1945). Summarized by Gagge AP, Herrington LP: Physiological effects of heat and cold. Ann Rev Physiol 9:409-428, 1947. 2. O'Keeffe KM: Accidental hypothermia: a review of 62 cases. JACEP 6:11, 1977. 3. Kugelberg J, Schuller II, Berg B, et al: Treatment of

10:3 (March) 1981 Ann Emerg Med 165/71