ORIGINAL C O N T R I B U T I O N heroin poisoning

Is Admission After Intravenous

Overdose Necessary?

Heroin

From the Division of Emergency Medicine, Texas A&M University College of Medicine, College Station, Texas;* and Department of Emergency Medicine, Texas Tech University School of Medicine, E1 Paso. ~

Received for publication June 24, 1991. Revision received March 19, 1992. Accepted for publication April 20, 1992.

Presented at the Society for Academic Emergency _Medicine Annual Meeting in Washington, DC, May 1991.

David A Smith, MD, FACEP*

Lawrence Leake, MD t

James Randall Loflin, MD t

Donald M Yealy, MD, FACEP*

Study object ives: To investigate the time of onset and incidence of complications in patients presenting to the emergency department with

an IV heroin overdose and the need for routine admission of such patients.

Methods: A retrospective chart review of hospital and emergency

medical service records of 124 patient visits involving IV heroin over- dose over a five-month period. We also reviewed the death certificates

of 115 persons having succumbed to a narcotic overdose over a 44-

month period and compared these with our hospital records.

S e t t i n g : Urban county hospital.

Type of par t ic ipants : Patients presenting to the ED with an IV

heroin overdose.

Results: There were five deaths in the ED, 12 hospital admissions,

and 107 patients who were discharged home. Neither delayed onset of pulmonary edema nor recurrence of respiratory depression was observed. Of the 115 persons having succumbed to a narcotic overdose,

eight had been seen previously at our hospital for a heroin overdose. There is no evidence that any of these eight deaths would have been prevented by a 24-hour hospital observation period.

Conclusion: Complications arising from an IV overdose of heroin are

usually evident on arrival in the El3 or shortly thereafter. On retrospec- tive review we have found no evidence that admission to the hospital

and 24 hours of observation are of benefit to patients who are awake,

alert, and lacking evidence of pulmonary complications after an IV heroin overdose.

[Smith DA, Leake L, Loflin JR, Yealy DM: Is admission after intravenous

heroin overdose necessary? Ann Emerg MedNovember 1992;21:1326-1330.]

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rtARCOTIC OVERDOSE Smith et al

N T R O D U C T I O N Many advocate hospitalizing all patients subsequent to a heroin overdose for an observation per iod of 12 to 24 hours, citing recurrent respi ra tory depression and pulmonary edema as potential late-arising life-threatening complications. 1 Previous studies have included only patients who have been admitted to the hospital subsequent to a heroin overdose and have indicated a high incidence of such complications.Z Pulmonary edema has been cited with a frequency of 50% to 67%, pneumonia is said to occur in 30%, and death occurs in 8% to 9%. 3 The time at which these complications appear after the overdose has been var iably repor ted. 4

It is our hypothesis that patients who are admitted to the hospital are not representat ive of the entire spectrum of acute IV heroin overdose. There is no study in the l i terature that includes all victims of a heroin overdose presenting to the emergency depar tment .

We sought to determine the incidence and time of onset of complications in the entire populat ion of patients presenting to the ED after an overdose by IV heroin injection and to re-examine the need for routine admission and observation of all such patients.

M A T E R I A L S AND M E T H O D S We conducted a retrospective review of the ED records of all patients with a chief complaint or ED diagnosis of heroin or narcotic overdose at RE Thomason General Hospital , El Paso, Texas, between June 1 and November 30, 1989. If the patient was admitted to the hospital , a review of the inpatient record was performed to determine the course, treatment, and final diagnosis. The records of the City of El Paso Depar tment of Emergency Medical Services also were examined to identify patients who were t ranspor ted with a heroin or narcotic overdose during the same time period.

We studied patients who were documented to have respi- ratory depression (defined as respirat ions of ten or less). This was performed to exclude patients who were only som- nolent as the result of drug abuse and had not t ruly sustained an overdose. We also included only patients who had evidence of IV narcotic abuse through either historic or physical evidence (ie, fresh needle marks). Patients who had enteral exposure to narcotics were excluded. None of the patients by their history used a narcotic other than heroin. However, we cannot demonstrate that heroin was the drug causing the overdose.

From each record, we collected patient age, sex, method of arr ival , field t reatment , and response to naloxone. We also sought information about the presentat ion at the scene of the overdose, including Glasgow Coma Scale, respi ra tory effort, vital signs, and skin condition. When available, we obtained information about the pat ient ' s mental status and vital signs on presentat ion in the ED~ route and dosage of naloxone, and whether there was any evidence of alcohol or

drug use other than narcotics. Time of observation before discharge from the ED or admission to the hospital also was noted. As is customary in our hospital, none of the patients discharged from the hospital had drug screening for narcotics performed.

Telephone follow-up of patients discharged from the hos- pi ta l was initially attempted. However, few patients had tele- phones or had a number recorded by the registration clerks. In cases in which a telephone number was available, usually it was incorrect or the answering par ty was not helpful. Subsequently, each pat ient was sent a let ter by certified mail requesting that they contact us by telephone. Death certifi- cates from the E1 Paso County Medical Examiner 's office were reviewed to determine if any of these patients had died subsequent to t reatment at our hospital.

In addit ion, death certificates were used to obtain the name and address of 115 patients who died from a narcotic overdose between January 1987 and August 1990. This was used to determine if the pat ient had a p r io r visit at RE Thomason Hospital and, if so, for what reason.

The names of all patients discharged from the hospital were also used to determine if the patients were t ranspor ted by emergency medical services (EMS) personnel a second time during the study per iod because of drug overdose, unconsciousness, or respi ra tory distress.

R E S U L T S Characteristics of the 124 patients who presented with a heroin overdose during the study per iod are presented (Table 1). One pat ient was seen three times. The five patients who died

Table 1. Characteristics o f 124 patients

No. %

Age (years) < 20 6 4.8 20-30 64 52 30-40 44 35 40-50 6 4.8 > 50 4 3.2 Average 30

Sex Male 117 94 Female 7 5.6

Evidence of alcohol iatoxicatien 58 47 Means of arrival

Private vehicle 11 8.8 EMS 113 91

Disposition Died in ED 5 4 Admitted 12 9.6 Not admitted 107 86

Medical complications Pulmonary edema 3 2.4 Hypoxic encephalopathy 2 1.6 Aspiration pneumonia 1 0,8 Death 5 4 Total 11 8,9

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N A R C O T I C O V E R D O S E Smith et al

were in cardiac ar res t when EMS personnel first a r r ived and remained so during t ranspor t to the hospital. Of patients with a heroin overdose t ransported by EMS personnel during the six-month study period, RE Thomason Hospital received 88 (78%). The other six hospitals in the city collectively received the remaining 25 (22%).

Twelve patients (10%) were admitted. Two patients were admitted to the ICU because of hypoxic encephalopathy. Both remained comatose in the ED after the adminis trat ion of naloxone. Three patients were admitted because of pulmonary edema, each evident within 20 minutes of a r r iva l in the ED. One pat ient appeared relatively well except for nausea on admission but was moved to the major resuscitation room 19 minutes later and intubated because of increasing respiratory distress. Another patient was confused after the adminis trat ion of naloxone and was noted to be developing respiratory distress five minutes after presentation. The th i rd patient was noted to be in resp i ra tory distress on presenta- tion to the ED. Aside from those who died or developed pulmonary edema, only one pat ient underwent endotracheal intubation in the course of therapy. This patient was observed to have aspi ra ted gastric contents and was admitted for an aspirat ion pneumonia. In addit ion, patients were admitted for multiple drug overdose (one), drug overdose (two), withdrawal (one), and t reatment and detoxification (two).

Most patients (107)were not admit ted despite the fact that many of them were quite seriously ill when first at tend- ed. Forty-one (38%) had a recorded Glasgow Coma Scale of 3 on presentat ion (average of all patients not admitted 6.1). Thirty-five patients (33%) were noted to be apneic, and 27 (25%) were cyanotic at the time of presentat ion. Twenty- four (22%) were diaphoretic. Pat ients who were not admit- ted were either discharged by the treat ing physician (46, or 37%), left against medical advice from the ED (42, or 34%), or pulled out their IV line and walked out of the ED without formal disposition (19, or 15%).

Because this study is based on a char t review, t reatment was not s tandardized. However, 91 patients received an IV dose of 2 mg (73 patients) or 4 mg (18 patients) naloxone in the ED. Twenty-six received no naloxone. Ninety-six patients were given in t ramuscular (IM) naloxone and the usual dose was 2 mg (83 patients). Although, 87 patients received both IM and IV doses. Seven patients were sufficiently resuscitat- ed in the field with bag-valve-mask ventilation and despite

Observation Time No, % -

30 Minutes or less 7 6.5 More than 30 minutes 8 7.5 More than 1 hour 18 16.8 More than 2 hours 31 29 More than 4 hours 16 15 More than 6 hours 9 8.4 More than 8 hours 2 1.9 Unknown 16 15

Table 2, Observation time in 107 patients not admitted

initially low respi ra tory rates never received any naloxone. Patients were discharged at the discretion of the attending physicians. Only 14 patients who were discharged had chest radiographs; all were normal.

Observat ion in the ED before discharge occurred for var iable periods of time (Table 2). Seven had disposition within 30 minutes of presentat ion. Fif ty-four were observed for more than two hours. Patients who were observed for longer than four hours generally requi red this because of intoxication with alcohol and/or other non-narcotic drugs. One pat ient was t reated with a naloxone drip because of incomplete initial response, which in retrospect apparent ly was due to intoxication with non-narcotic drugs. None of the remaining patients was observed to have recurrent narcosis or resp i ra tory depression, and none required addit ional doses of naloxone beyond those given on admission.

Registered letters were re turned with receipt signed by the pat ient in 15 cases. Return receipt was signed for the patient in 25 cases. The remainder of the letters were unde- l iverable for various reasons.

None of the patients in our study was ret ransported by E1 Paso EMS subsequent to discharge from our hospital for respiratory distress, respiratory depression, or drug overdose.

Review of the County Medical Examiner 's records deter- mined that 115 patients had died at least in pa r t from a nar- cotic overdose between January 1987 and August 1990. Of these, 28 had been seen previously at our hospital , eight for a heroin overdose. The shortest time intervals between the pr ior visit and subsequent death were six and 24 days in two patients. The reason for the pr ior visit in both of these cases was a heroin overdose.

D I S C U S S I O N

In the past , clinical studies of patients with a heroin over- dose have been conducted only on patients who were admit- ted to the hospital. If we had chosen to include only patients who were admitted to the hospital, the incidence of pulmonary edema would not have been 2.4% but ra ther 25%. The inci- dence of other complications such as aspirat ion pneumonia and hypoxic encephalopathy also would have been correspondingly higher.

The recommendat ion that all patients need to be admitted to the hospital was first made before the introduct ion of naloxone and has not been challenged since then. Patients who have been incompletely resuscitated with nalorphine have developed delayed onset of respi ra tory depression. 5 However, nalorphine has agonist propert ies and is capable of inducing respi ra tory depression.6 Naloxone has replaced nalorphine for the t reatment of narcotic overdose because of its lack of agonist propert ies .

Heroin is rapidly metabolized to morphine, which has a dura t ion of action of four to five hours. Although the reap- pearance of some sedation is acceptable, the antagonist should be present long enough to prevent l ife-threatening respi ra tory depression.

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NARCOTIC OVERDOSE Smith et al

Some studies have shown that naloxonc will antagonize the effects produced by morphine for only 45 to 70 minutes. Because of this, concern has been raised that patients may develop recur ren t narcot ic- induced resp i ra tory depression after t reatment with naloxone.7 IV infusions of naloxone have been advocated because of this concern. 8

There is evidence that naloxone in large doses has effects that last much longer than generally thought. During the first hour after adminis trat ion of naloxone, the serum con- centration diminishes rapidly. Because of this, the effect of a small but therapeut ic dose (0.4 mg) may d isappear quickly. However, between 20 minutes and four hours, the elimina- tion of naloxone proceeds with f i rs t -order kinetics, with an average half-life of 64 minutes. Jasinski et al 9 showed the durat ion of action of 15 mg naloxone to be at least nine h o u r s .

The pharmacology of naloxoue is, in fact, quite complex. A metabolite of naloxone (6-a-naloxol) has a much longer half-life than naloxonc. Because this metabolite has both agonistic as well as antagonistic effects, the presence of the metabolite may produce some sedation but not respi ra tory depression. Additionally, the p-opiate receptors are thought to mediate narcot ic- induced respi ra tory depression, whereas both p- and s~-receptors are thought to mediate the sedative effects. Thus, n-receptor stimulation may persist under cer- tain circumstances and produce sedation but not respi ra tory depression.

When naloxone is used in modest doses by contemporary standards (1 to 2 mg IV), there is evidence that it antagonizes the respi ra tory depressant effect of morphine for about six h o u r s . 10

Usually, our patients received relatively large doses of naloxone on presentat ion to the ED. Although many received IM administrat ion, the usefulness of this route is not clear. There is stone evidence that IM administrat ion prolongs the effect of naloxone. 11

The limitations of this review are important . The present study addressed the question of what to do with a pat ient who by all appearances has sustained an IV overdose with heroin. With the drug screens that are commonly available in the ED, it usually is not possible to determine which nar - cotic is involved. The answer to the question of what to do with a pat ient who has sustained an overdose known or proven to be heroin is of interest but is not the one that is commonly encountered.

Our results should not be extrapola ted to populations outside the study group. We have not included patients who stated they use methadone, propoxaphene , pentazocine, or any narcotic other than heroin. If this was the case, the r isk of delayed ill effect could be much higher than our data would indicate. In our populat ion, the use of such drugs probably occurs infrequently.

The results also should not he applied to situations where there is evidence of enteral exposure to narcotics. This is important as the enteral route produces a much longer dura-

iii i i i

tion of action. Methadone is a narcotic that may be part icu- lar ly problematic because it may be abused by addicts on maintenance programs. Methadone has a prolonged sedative and ant iwithdrawal effect when given orally. However, after paren te ra l adminis trat ion in human beings, methadone has a dura t ion of action similar to that of morphine.12 Although we have been unable to find recurrence of respi ra tory depression in patients who have only paren tera l exposure to narcotics, there are repor ted cases with an ingestion of methadone or propoxyphene. 13,14

Patients who intend to mislead the physician probably can and may cause themselves harm. For this reason, patients who have ingested narcotics in a suicide attempt are not good candidates for discharge from the hospital..41l our patients were recreat ional drug abusers and not suicidal.

Additionally, there may be other reasons to doubt the reliabil i ty of a pat ient ' s history. The availabili ty of heroin in E1 Paso is quite high. In other communities, this may not be the case, and the IV use of other drugs may be more common.

In our study, complications such as hypoxic cncephalopathy and pulmonary edema were obvious either on admission or within 20 minutes thereafter. Because no patient deter iorat- ed beyond the first 20 minutes in the ED, we are unable to suggest an optimal per iod of observation beyond this. The staff physicians felt comfortable in discharging most patients after two to four hours of observation. The exceptions were patients who also were intoxicated with alcohol or other drugs. I t would be prudent to evaluate the patient 's pulmonary status carefully before discharge for evidence of pulmonary edema or aspirat ion pneumonia. In our study, performance of a chest radiograph was at the discretion of the at tending physician. Only 14 of the patients who were discharged had chest radiographs performed.

Follow-up of all or most patients discharged from the hospital is difficult. Most patients could not be reached, and those who were did not contact us as requested. However, we believe that if patients had suffered delayed ill effects, they would have come to our attention in most cases. The records of the El Paso City EMS system showed that 78% of patients with a narcotic overdose in E1 Paso were t ranspor ted to our hospital. The other six hospitals in E1 Paso received only 22% of these patients. None of the patients in our study re turned to the ED except one patient who was seen on three separate and temporal ly disparate occasions with a heroin overdose. Because most patients ar r ived by EMS, it is likely that had a complication such as recurrent respira tory depression or pulmonary edema occurred, the patient would have re turned by the same manner in most cases. None of our patients were again t ranspor ted by EMS because of a complication relating to the overdose.

Because it is possible that patients would not have come to our attention because they had died, we decided to inves- tigate actual deaths by narcotic overdose in our locale to see if we could identify any that would have been prevented by

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NARCOTIC OVERDOSE Smith et al

a policy of admission for observation. From the County Medical Examiner's Office, we identified 115 deaths at tr ibuted at least in par t to a narcotic overdose in a 44-month period. In none of these cases had that individual presented with a heroin overdose close enough to their death to represent a case of recurrent respiratory depression or delayed onset of pulmonary edema. The earliest presentation had been six days earlier.

The number of patients in this study was relatively small, and admittedly, follow-up was incomplete. It is possible that with a larger number of patients or more complete follow-up that patients would have been identified as having sustained an adverse outcome escaping detection within the first few hours of treatment and observation. Because we cannot pre- vent patients who are discharged from the hospital from using drugs a second time, we would never know if the adverse event was precipitated by the first. Fur ther examination of this issue will require a study in an insti tution where all such patients are admitted for a 24-hour observation period.

C O N C L U S I O N

We have found on retrospective review that complications after an IV heroin overdose are relatively few in number and usually evident on or soon after presentation of the patient in the ED.

We identified no evidence that admission to the hospital and 12 to 24 hours of observation are necessary for patients who are awake, alert, and lacking evidence of pulmonary complications after a brief observation period of two to four hours in most cases. Associated intoxication with alcohol or other drugs may require longer periods of observation.

Patients who do not fully regain consciousness or are confused or otherwise mentally incompetent should not be allowedto leave or sign out of the hospital against medical advice.

R E F E R E N C E S

1. Allen T: Narcotics, in Rosen P, Baker F J, Barken RM, et al (eds): Emergency Medicine, St Louis, C V Mosby, 1988, p 2125-2140.

2. Vincent A, Perret C: Hospital morbidity and morality of acute opiate intoxication. Presse Med 1990;19:1403-1406.

3. Duberstein JL, Kaufrnan DM: A clinical study of and epidemic of heroin intoxication and heroin-induced pulrnena ry edema. Am J Med 1971;51:704:714.

4. Morrison WI, Wetherill S, Zyroff J: The acute pulmonary edema of heroin intoxication. Radiology1970;97:347-351.

5. Steinberg AD, Karliner JS: The clinical spectrum of heroin pulmonary edema. Arch Intern Med 1968;122:122-127.

6. Martin WR: Naloxone. Ann Intern Med 1976;85:765-768.

7. Ngai SH, Berkowitz BA, Yang JC, et al: Pharrnacokinetics of naloxone in rats and in man: Basis for its potency and short duration of action. Anesthesiology 1976;44:398-401.

8. Goldfrank L, Weisrnan RS, Errick JK, et al: A dosing nornograrn for continuous infusion intravenous naloxone. Ann Emerg Med 1986;15:566-570.

9. Jasinski B, Martin W, Haertzen C: The human pharmacology and abuse potential of N-allylnoroxyrnorphene (nalexone). J Pharmacol Exp Thor 1967;157:420-426.

10. Konieczko KM, Jones JG, Barrowcliffe MP, et al: Antagonism of morphine-induced respiratory depression with nalrnefene. BrJ,4nesth 1988;61:318-323.

11. Longnecker BE, 6razis P, Eggers GWN: Naloxone antagonism of morphine induced respiratory depression. ,4nesth ,4nalg 1973;52:447-452.

12. Jaffe JH, Martin WR: Opioid analgesics and antagonists, in Goodman L, Gilman A (eds): The Pharmacological Basis of Therapeutics, ed 6. New York, Macmillan, 1980.

13. Frand UI, Shim CS: Methadone-induced pulmonary edema. Ann Intern Med 1972;76:975.

14. Bradberry JC, Raebel MA: Continuous infusion of naloxone in the treatment of narcotic overdose. Drug Intefl Clin Pharm 1981;15;945-950.

Address for reprints: David A Smith, MD Department of Emergency Medicine Scott and White Memorial Hospital and Clinic 2401 South 31st Street Temple, Texas 76508

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