panic membrane is intact and the canal not impacted with cerumen that may impair stimulation, cold water is intro- duced into the canal. Normal nystagmus is regular, rhyth- mic, and lasts two to three minutes in response to caloric stimulation. As consciousness is lost acutely from meta- bolic or supratentorial brain disease, the fast component progressively disappears and the slower reflex eye move- ments carry the eyes tonically toward the irrigated ear.2, 3 When present this reaction indicates intact brainstem func- tion. Severe brainstem injury or deep metabolic depression of brainstem traction may alter or obliterate the caloric re- sponse.

If normal nystagmus is elicited, the patient is phys- iologically awake, and the unresponsiveness cannot be caused by structural or metabolic disease of the nervous system. Conversion disorders, catatonia, malingering, and other causes of psychogenic unresponsiveness should be considered.

In summary, in the unconscious patient with intact

brainstem hmctions, cold water irrigation produces slow de- viation of the eyes to the same side of stimulation. Warm water irrigation should produce deviation to the side op- posite the site of irrigation. Not "COWS" but cold - - same, warm - - opposite in the unresponsive patient.

J Stephen Huff, MD Department of Emergency Medicine University of Cincinnati Cincinnati, Ohio

l. Baloh RW, Honrubia V: Clinical Neurophysiology of the Ves- tibular System. Philadelphia, FA Davis Company, 1979, p 134.

2. Baker PB: Caloric testing, in Roberts JR, Hedges JR (eds): Clinical Procedures in Emergency Medicine. Philadelphia, WB Saunders Company, 1985.

3. Plum F, Posner JB: The Diagnosis of Stupor and Coma. Phila- delphia, FA Davis Company, 1980, pp 54-56.

Beta Blocker Overdoses

To the Editor: The following case studies present two patients with beta

blocker overdoses. Case 1: A 27-year-old woman who had ingested 40 80-mg

Inderal ® tablets less than one hour before was admitted to the emergency department. She was given ipecac and with- in minutes suffered cardiovascular decompensation. Her pulse was 40 and blood pressure was 55/30 mm Hg. She was given 7.5 mg glucagon IVP Within minutes her pulse and blood pressure were restored to normal range. They re- mained stable for the duration of her emergency treatment. She was transferred to the MICU on a continuous infusion of glucagon at 2.5 mg/h. She was weaned from the infusion after 12 hours and was discharged within the next 72 hours without incident.

Case 2: Paramedics were called to a residence because of a report that a young woman had taken 100 40-mg Inderal ® tablets. When they arrived, the patient was semiconscious, had a weak pulse, and no apparent blood pressure. An IV line was started and she was transported to the ED. On ar- rival CPR was in progress and the rhythm had deteriorated from sinus bradycardia to asystole. After extensive resusci- tation techniques were applied the patient was pronounced dead. Only 3 mg glucagon were available in the ED. Two more were obtained 30 minutes after the patient arrived.

These cases point out several clear lessons. First, the rapidity of onset of cardiovascular compromise in overdose of beta-blocking agents, particularly Inderal ®, should cause the emergency physician to be very cautious in the use of ipecac in these patients. Ipecac is relatively contraindicated

in beta blocker overdoses. Second, glucagon, which has been recognized since 1980 as effective in reversing bra- dycardia and hypotension, should be available for immedi- ate use on all paramedic vans and in all EDs. The recom- mended dosage of glucagon is 100 to 150 ~g/kg IVP followed by a continuous infusion of 1 to 5 mg/h for the duration of four to five half-lives of the specific beta blocker. This should be accompanied by standard overdose therapy of la- vage with large-bore orogastric tube with 3 to 5 L sodium chloride. Charcoal should be administered in a dose of 1 gm/kg or five times the ingested dose of the beta blocking agent. Because of enterohepatic circulation pulse charcoal should be administered in a dose of 20 to 40 g every two to four hours. A cathartic should be used as well. Glucagon should be approved for paramedic usage in the field accord- ing to poison center guidelines.

Similarly, IV pyridoxine has been shown to be extremely effective in treatment of seizures due to isoniazid overdose. The IV dose of pyridoxine is 1 mg pyridoxine IV push for every 1 mg of isoniazid ingested. If the quantity of isoniazid ingested is unknown, then 5 g should be used. A recent survery of the EDs in our area shows that neither of these drugs are readily available. We believe it advisable that all directors check their drug supplies.

John Wilkinson, DO Clinical Toxicology Associates of San Diego Poway, California

Manual Intubation: Transmitter of Disease?

To the Editor: While practicing the technique of manual oral endo-

tracheal intubat ion on the intubat ion mannequin we noticed a disturbing fact. Every successful intubater was noted to have abrasions over the second and third metacar-

15:8 August 1986 Annals of Emergency Medicine 982/171