Spinal motion restriction: an educational and implementation program to redefine prehospital spinal assessment and care

INTRODUCTION

Prehospital spine immobilization has long been applied to victims of trauma in the United States and up to 5 million patients per year are immobilized mostly with a cervical collar and a backboard.

OBJECTIVE

The training of paramedics and emergency medical technicians on the principals of spine motion restriction (SMR) will decrease the use of backboards.

METHODS

The training for SMR emphasized the need to immobilize those patients with a significant potential for an unstable cervical spine fracture and to use alternative methods of maintaining spine precautions for those with lower risk. The training addressed the potential complications of the use of the unpadded backboard and education was provided about the mechanics of spine injuries. Emergency medical services (EMS} personnel were taught to differentiate between the critical multisystem trauma patients from the more common moderate, low kinetic energy trauma patients. A comprehensive education and outreach program that included all of the EMS providers (fire and private), hospitals, and EMS educational institutions was developed.

RESULTS

Within 4 months of the policy implementation, prehospital care practitioners reduced the use of the backboard by 58%. This was accomplished by a decrease in the number of patients considered for SMR with low kinetic energy and the use of other methods, such as the cervical collar only.

CONCLUSION

The implementation of a SMR training program significantly decreases the use of backboards and allows alternative methods of maintaining spine precautions.

Which emergency medical dispatch codes predict high prehospital nontransport rates in an urban community?

BACKGROUND

The Medical Priority Dispatch System (MPDS) is a commonly used computer-based emergency medical dispatch (EMD) system that is widely used to prioritize 9-1-1 calls and optimize resource allocation. There are five major priority classes used to dispatch 9-1-1 calls in the San Francisco System; Alpha codes are the lowest priority (lowest expected acuity) and Echo are the highest priority.

OBJECTIVE

We sought to determine which MPDS dispatch codes are associated with high prehospital nontransport rates (NTRs).

METHODS

All unique MPDS call categories from 2009 in a highly urbanized, two-tier advanced life support (ALS) system were sorted according to highest NTRs. There are many reasons for nontransport, such as "gone on arrival," and "patient denied transport." Those categories with greater than 100 annual calls were further evaluated. MPDS groups that included multiple categories with NTRs exceeding 25% were then identified and each category was analyzed. Results. EMS responded to a total of 81,437 calls in 2009, of which 18,851 were not transported by EMS. The majority of the NTRs were found among "cardiac/ respiratory arrest/death," "assault/sexual assaults," "unknown problem/man down," "traffic/transportation accidents," and "unconscious/fainting." "Cardiac or respiratory arrest/death -obvious death" (9B1) had the highest overall nontransport rate, 99.25% (1/134), most likely due to declaration of death. "Unknown problem -man down -medical alert notification" had the second highest NTR, 67.22% (138/421). However, Echo priority codes had the highest overall nontransport rates (45.45%) and Charlie had the lowest (13.84%).

CONCLUSIONS

The nontransport rates of individual MPDS categories vary considerably and should be considered in any system design. We identified 52 unique call categories to have a 25% or greater NTR, 18 of which exceeded 40%. The majority of NTRs occurred among the "cardiac/respiratory arrest/death," "assault/sexual assaults," "unknown problem/man down," "traffic/transportation accidents," and "unconscious/fainting" categories. The higher the priority code within each subset (AB vs. CDE), the less likely the patient was to be transported. Charlie priority codes had a lower NTR than Delta, and Delta was lower than Echo. Charlie codes were therefore the strongest predictors of hospital transport, while Echo codes (highest priority) were those with the highest nontransport rates and were the worst predictors of hospital transport in the emergent subset.

Accuracy of the initial diagnosis among patients with an acutely altered mental status

OBJECTIVES

The objectives of this prospective observational study were to: (1) determine the accuracy of physician diagnosis in patients with an acutely altered mental status (AMS) within the first 20 min of emergency department (ED) presentation; and (2) access if physician confidence in early diagnosis correlates with accuracy of diagnosis.

METHODS

A prospective observational convenience study was conducted of 112 adult patients who presented to an urban county ED with AMS (Glasgow Coma Scale (GCS) score ≤14) between August 2008 and July 2009. Within the first 20 min of patient presentation to the ED, treating physicians were asked to record their best diagnostic guess of the cause of the patient's AMS and their confidence in this diagnosis. Serial hourly GCS was performed and the results of all diagnostic testing were recorded. Blinded investigators determined the final consensus diagnostic cause of the patient's AMS.

RESULTS

The final consensus diagnoses for AMS aetiologies were as follows: isolated alcohol intoxication 31%, other (psychotic episodes, underlying dementia) 21%, combination alcohol/other drug intoxications 18%, isolated other drug intoxications 10%, other metabolic derangements 6%, cerebrovascular accident/transient ischaemic attack 4%, seizures/post-ictal states 4%, traumatic brain injuries 3%, isolated opiate intoxications 2%, isolated benzodiazepine intoxication 1% and septic episode 1%. The emergency physician's initial diagnosis of the AMS patient correlated with the accuracy of the final diagnosis (r(2)=0.807). The quintiles of confidence of diagnosis were: 0-20% degree of confidence had a 33% diagnostic accuracy, 21-40% had 25% accuracy, 41-60% had 43% accuracy, 61-80% had 52% accuracy and those with 81-100% confidence of initial diagnosis had 78% accuracy. Of the 106 patients with an initial diagnosis, 52 (51%) had a head CT performed, with eight (8%) having an acute abnormality.

DISCUSSION

Early diagnoses of AMS patients are moderately accurate. Few early misdiagnoses of AMS patients were clinically relevant. Physicians' greater degree of confidence in their diagnosis correlated with greater accuracy.

A multisite assessment of the American College of Surgeons Committee on Trauma field triage decision scheme for identifying seriously injured children and adults

BACKGROUND

The American College of Surgeons Committee on Trauma (ACSCOT) has developed and updated field trauma triage protocols for decades, yet the ability to identify major trauma patients remains unclear. We estimate the diagnostic value of the Field Triage Decision Scheme for identifying major trauma patients (Injury Severity Score [ISS] ≥ 16) in a large and diverse multisite cohort.

STUDY DESIGN

This was a retrospective cohort study of injured children and adults transported by 94 emergency medical services (EMS) agencies to 122 hospitals in 7 regions of the Western US from 2006 through 2008. Patients who met any of the field trauma triage criteria (per EMS personnel) were considered triage positive. Hospital outcomes measures were probabilistically linked to EMS records through trauma registries, state discharge data, and emergency department data. The primary outcome defining a "major trauma patient" was ISS ≥ 16.

RESULTS

There were 122,345 injured patients evaluated and transported by EMS over the 3-year period, 34.5% of whom met at least 1 triage criterion and 5.8% had ISS ≥ 16. The overall sensitivity and specificity of the criteria for identifying major trauma patients were 85.8% (95% CI 85.0% to 86.6%) and 68.7% (95% CI 68.4% to 68.9%), respectively. Triage sensitivity and specificity, respectively, differed by age: 84.1% and 66.4% (0 to 17 years); 89.5% and 64.3% (18 to 54 years); and 79.9% and 75.4% (≥55 years). Evaluating the diagnostic value of triage by hospital destination (transport to Level I/II trauma centers) did not substantially improve these findings.

CONCLUSIONS

The sensitivity of the Field Triage Decision Scheme for identifying major trauma patients is lower and specificity higher than previously described, particularly among elders.

Detailed analysis of prehospital interventions in medical priority dispatch system determinants

BACKGROUND

Medical Priority Dispatch System (MPDS) is a type of Emergency Medical Dispatch (EMD) system used to prioritize 9-1-1 calls and optimize resource allocation. Dispatchers use a series of scripted questions to assign determinants to calls based on chief complaint and acuity.

OBJECTIVE

We analyzed the prehospital interventions performed on patients with MPDS determinants for breathing problems, chest pain, unknown problem (man down), seizures, fainting (unconscious) and falls for transport status and interventions.

METHODS

We matched all prehospital patients in complaint-based categories for breathing problems, chest pain, unknown problem (man down), seizures, fainting (unconscious) and falls from January 1, 2004, to December 31, 2006, with their prehospital record. Calls were queried for the following prehospital interventions: Basic Life Support care only, intravenous line placement only, medication given, procedures or non-transport. We defined Advanced Life Support (ALS) interventions as the administration of a medication or a procedure.

RESULTS

Of the 77,394 MPDS calls during this period, 31,318 (40%) patients met inclusion criteria. Breathing problems made up 12.2%, chest pain 6%, unknown problem 1.4%, seizures 3%, falls 9% and unconscious/fainting 9% of the total number of MPDS calls. Patients with breathing problem had a low rate of procedures (0.7%) and cardiac arrest medications (1.6%) with 38% receiving some medication. Chest pain patients had a similar distribution; procedures (0.5%), cardiac arrest medication (1.5%) and any medication (64%). Unknown problem: procedures (1%), cardiac arrest medication (1.3%), any medication (18%). Patients with Seizures had a low rate of procedures (1.1%) and cardiac arrest medications (0.6%) with 20% receiving some medication. Fall patients had a lower rate of severe illness with more medication, mostly morphine: procedures (0.2%), cardiac arrest medication (0.2%), all medications (28%). Unconscious/fainting patients received the following interventions: procedures (0.3%), cardiac arrest medication (1.9%), all medications (32%). Few stepwise increases in the rate of procedures or medications were seen as determinants increased in acuity.

CONCLUSION

Among these common MPDS complaint-based categories, the rates of advanced procedures and cardiac arrest medications were low. ALS medications were common in all categories and most determinants. Multiple determinants were rarely used and did not show higher rates of interventions with increasing acuity. Many MPDS determinants are of modest use to predict ALS intervention.

How many emergency dispatches occurred per cardiac arrest?

BACKGROUND

The Medical Priority Dispatch System (MPDS) is an emergency medical dispatch (EMD) system that is widely used to prioritize 9-1-1 calls and optimize resource allocation. Calls are assigned an MPDS determinant, which includes a number (1-32) representing chief complaint and priority (Alpha through Echo) representing acuity.

OBJECTIVE

This study evaluates the number of emergency dispatches per cardiac arrest (NOD-CA) in cardiac arrest and non-cardiac arrest MPDS determinants.

METHODS

All patients assigned a determinant by MPDS from January 1, 2008 to June 30, 2009 in a large metropolitan area were included. Prehospital electronic patient care records were linked with dispatch data. For each MPDS determinant, the number of calls for which the paramedic impression was listed as "Cardiac Arrest - Non-Traumatic" was tabulated. The NOD-CA was calculated for each cardiac arrest and non-cardiac arrest MPDS determinant. Non-MPDS calls with cardiac arrests were analyzed separately.

RESULTS

A total of 101,642 patients were included. Among them, 555 had "Cardiac Arrest - Non-Traumatic" listed as the paramedic impression. The Cardiac/Respiratory Arrest/Death protocol had the highest number of cardiac arrests (285), followed by Breathing Problems (99) and Unconscious/Fainting (76). Overall, 183 dispatched occurred for each cardiac arrest, 131 of which resulted in a lights and sirens response. The NOD-CA was 7 in the Cardiac Arrest/Death protocol, 122 in Breathing Problems, and 104 in Unconscious/Fainting. 31 Cardiac arrests occurred in non-MPDS dispatch categories (N=62,989), most of which were calls for medical assistance from police or fire units.

CONCLUSIONS

MPDS was designed to detect cardiac arrest with high sensitivity, leading to a significant degree of mistriage. The number of dispatches for each cardiac arrest may be a useful way to quantify the degree of mistriage and optimize EMS dispatch. This large descriptive study revealed a low NOD-CA in most cardiac arrest MPDS determinants. We demonstrated significant variability in the NOD-CA among non-cardiac arrest MPDS determinants, and few cardiac arrests in non-MPDS dispatch categories.

Organizational issues in the implementation of a hospital-based syringe exchange program

Little published information exists to guide health care institutions in establishing syringe exchange program (SEP) services. To address this gap, this article discusses organizational issues encountered in the implementation of a hospital-based SEP in San Francisco, California (USA). Investigators collaborated with a community organization in implementing a county hospital-based SEP. SEP services integrated into a public hospital presented unique challenges directly related to their status as a health care institution. In the course of introducing SEP services into a hospital setting as part of a clinical trial, various ethical, legal, and logistical issues were raised. Based on these experiences, this paper provides guidance on how to integrate an SEP into a traditional health care institution.

Validation of Low-Acuity Emergency Medical Services Dispatch Codes

BACKGROUND

Computer-aided dispatch systems are used to assess the severity of a 9-1-1 caller's complaint and then assign an appropriate level of emergency medical services (EMS) response.

OBJECTIVE

To evaluate a group of low-acuity codes (defined as requiring advanced life support [ALS] intervention in fewer than 10% of cases) that has been derived and validated in one community.

METHODS

All of the 9-1-1 medical calls assigned to these predetermined emergency medical dispatch codes between January 1, 2004, and July 1, 2004, were analyzed. ALS care was defined as receiving one or more of the following: pulse oximetry measurement, blood glucose measurement, cardiac defibrillation, administration of any medication, airway maneuvers, or the placement of an intravenous (IV) catheter. A more restrictive definition of ALS care (use of IV fluid bolus, medication administration, intubation, or defibrillation) was also calculated.

RESULTS

A total of 1,799 calls were assigned low-acuity dispatch codes, and 1,597 met inclusion criteria. None of the 26 dispatch codes were found to be low-acuity by the study definition. Fifty-six percent of these patients received ALS care. Placement of an IV-catheter was the ALS intervention used most frequently (45% of cases), followed by pulse oximetry measurement (32%), glucose measurement (22%), medication administration (11%), intubation (0.13%), and defibrillation (0%). The medication administered most frequent was morphine. When using the more restrictive definition of acuity, patients in 19 of the 28 categories received ALS intervention less than 10% of the time. Patients in the other seven categories were considered high-acuity 13% to 36% of the time.

CONCLUSION

Dispatch codes that had previously been determined to be low-acuity were found not to be so in this community. The variation in clinical practice is likely explained by a more precautionary approach to care in this EMS system and the increased use of analgesics. This study demonstrates the need to define the optimal subset of prehospital patients who would benefit from these treatments.

The Ability of Emergency Medical Dispatch Codes of Medical Complaints to Predict ALS Prehospital Interventions

OBJECTIVE

The Medical Priority Dispatch System (MPDS) is an emergency medical dispatch (EMD) system that is commonly used to triage 9-1-1 calls and optimize paramedic and EMT dispatch. The objective of this study was to determine the sensitivity, specificity, and positive and negative predictive values of selected MPDS dispatch codes to predict the need for ALS medication or procedures.

METHODS

Patients with selected MPDS codes between November 1, 2003, and October 31, 2005, from a suburban California county were matched with their electronic patient care record. The records of all transported patients were queried for prehospital interventions and matched to their MPDS classification [Basic Life Support (BLS) versus Advanced Life Support (ALS)]. Patients who received prehospital interventions or medications were considered ALS Intervention. With true positive = ALS by MPDS + ALS Intervention, true negative = BLS by MPDS + BLS Interventions, false positive = ALS by MPDS + BLS Interventions, and false negative = BLS by MPDS + ALS Interventions, the screening performance of the San Mateo County EMD system was determined for selected complaint categories (abdominal pain, breathing problems chest pain, sick person, seizures, and unconscious/fainting).

RESULTS

There were a total of 64,647 medical calls, and 42,651 went through the EMD process; 31,187 went through the EMD process and were transported; 22,243 of these were matched to a patient care record. The sensitivity and specificity with 95% confidence intervals in () were as follows: all EMD calls 84 (83-85), 36 (35-36); abdominal pain, 53 (41-65), 47 (43-51); chest pain 99 (99-100), 2 (1-3); seizure 83 (77-88), 20 (17-23), sick 59 (53-64), 51 (49-54), and unconscious/fainting 99 (98-100), 2 (2-3).

CONCLUSION

In our EMS system, MPDS coding for all medical calls had high sensitivity and low specificity for the prediction of calls that required ALS intervention. Chest pain and unconscious/fainting calls were screened with very high sensitivity but very low specificity.

Can emergency medical dispatch codes predict prehospital interventions for common 9-1-1 call types?

OBJECTIVE

The Medical Priority Dispatch System is an emergency medical dispatch (EMD) system that is widely used to categorize 9-1-1 calls and optimize resource allocation. This study evaluates the ability of EMD and non-EMD codes (calls not processed by EMD) to predict prehospital use of medications and procedures.

METHODS

All transported prehospital patients placed in an EMD or non-EMD category that exceeded 500 total calls from January 1, 2004, to December 31, 2006, in a suburban California county were matched with their prehospital electronic patient care record. These records (N = 69,541) were queried for the following prehospital interventions: basic life support (BLS) care only, intravenous line placement only, medication given, and procedures. Advanced life support (ALS) interventions were defined as the administration of a medications or a procedure. The numbers of medications and procedures that were performed on patients in each EMD code were measured.

RESULTS

Thirty-one of 141 EMD and non-EMD codes met inclusion criteria and comprised 73% of all calls during the study period. Non-EMD codes accounted for 48% of all calls in this study. Patients with shortness of breath, chest pain, diabetic problems, and altered mental status received the most medications. High rates of medication administration were also seen in the following codes: 17A (fall, 27%), 17B (fall, 14%), EMDX (unable to complete EMD process, 22%), MED (medical aid requested--details to follow, 26%), and MED3 (medical aid requested by police--code 3, 18%). Procedures were performed on only 0.9% of all calls, of which 75% were related to advanced airways. Higher rates of ALS interventions in higher-acuity categories (Alpha, Bravo, etc.) were seen in a number of EMD categories, including seizure, laceration/hemorrhage, sick, and traffic accident, but not seen in many categories, including abdominal pain, falls, and chest pain.

CONCLUSIONS

This study demonstrated only a modest ability of the EMD system to predict which patients would require ALS intervention. There were limited differences noted in the ALS rates between the different codes (Alpha, Bravo, etc.) in the same complaint category, bringing into question the utility of the multiple subgroups. Non-EMD codes made up a large portion of calls (48%) and should be included in future studies.

Patterns of Ecstasy-Associated Hyponatremia in California

STUDY OBJECTIVE

We describe the clinical characteristics of patients with ecstasy- (3,4-methylenedioxymethamphetamine [MDMA]) associated hyponatremia (serum sodium level <130 mmol/L) reported to the California Poison Control System during a 5-year period and determine whether a sex difference exists among patients with ecstasy-associated hyponatremia and hyponatremia-associated adverse outcomes.

METHODS

We performed a retrospective review of cases involving ecstasy intoxication reported to the California Poison Control System and recorded in its computerized database from January 1, 2000, through October 9, 2005. We excluded cases that did not involve MDMA exposure or in which there were no symptoms or were minimal effects only. Confirmation of exposure to MDMA was based on history of use and, when available, urine toxicology testing results positive for MDMA or amphetamine derivatives. Hyponatremia was defined as a measured serum sodium level less than 130 mmol/L.

RESULTS

A total of 1,436 cases potentially involving ecstasy were reported to the California Poison Control System during the 5-year study period, of which 891 were excluded according to the criteria described above. Of the 545 cases that met inclusion criteria, 296 (54.3%) were women and 249 (45.7%) were men. There were 188 cases (34.5%) with a documented serum sodium level, of which 73 (38.8%) reported hyponatremia (Na <130 mmol/L). Of the 73 subjects with hyponatremia, 55 (75.3%) were women and 18 (24.7%) men; of the 115 nonhyponatremic subjects, 50 (43.5%) were women and 65 (56.5%) were men. Among patients with a documented serum sodium level, female sex was associated with increased odds of hyponatremia (odds ratio [OR] 4.0; 95% confidence interval [CI] 2.1 to 7.6). Among women, those with hyponatremia demonstrated increased odds of coma (OR 3.9; 95% CI 1.2 to 12.9), whereas among men, no increased odds of hyponatremia-associated coma were observed (OR 0.8; 95% CI 0.15 to 4.0).

CONCLUSION

Female sex was associated with increased odds of hyponatremia and increased odds of hyponatremia-associated coma among persons with ecstasy intoxication and a documented serum sodium level reported to the California Poison Control System from 2000 to 2005. Multiple potential confounders, including spectrum bias, incomplete laboratory data, and individual differences in study subject characteristics, prevent determination of causality about sex differences in the incidence of ecstasy-associated hyponatremia and its complications.

Prescription naloxone: a novel approach to heroin overdose prevention

The mortality and morbidity from heroin overdose have increased in the United States and internationally in the last decade. The lipid solubility allows the rapid deposition of heroin and its metabolites into the central nervous system and accounts for the "rush" experienced by users and for the toxicity. Risk factors for fatal and nonfatal heroin overdoses such as recent abstinence, decreased opiate tolerance, and polydrug use have been identified. Opiate substitution treatment such as methadone or buprenorphine is the only proven method of heroin overdose prevention. Death from a heroin overdose most commonly occurs 1 to 3 hours after injection at home in the company of other people. Numerous communities have taken advantage of this opportunity for treatment by implementing overdose prevention education to active heroin users, as well as prescribing naloxone for home use. Naloxone is a specific opiate antagonist without agonist properties or potential for abuse. It is inexpensive and nonscheduled and readily reverses the respiratory depression and sedation caused by heroin, as well as causing transient withdrawal symptoms. Program implementation considerations, legal ramifications, and research needs for prescription naloxone are discussed.

Do medications affect vital signs in the prehospital treatment of acute decompensated heart failure?

INTRODUCTION

Prehospital treatment of patients with acute decompensated heart failure (ADHF) has been shown to decrease mortality and morbidity. Vital sign changes have been proposed as clinical endpoints in the evaluation of prehospital treatment for this condition.

OBJECTIVE

To examine the effect of prehospital treatments on vital signs among patients with ADHF.

METHODS

Records of an urban emergency medical services system from September 1, 2002, through September 1, 2003, were queried for patients who had a paramedic impression of shortness of breath or respiratory distress and had received nitroglycerin and/or furosemide. Demographics, initial and repeat vital signs (blood pressure, heart rate, respiratory rate, and oxygen saturation), and medications and doses were collected.

RESULTS

Three hundred nineteen patients were included; the average age was 77 (+/-12) years and 47% were male. Treatments administered to these patients included nitroglycerin, 296 (93%); furosemide, 194 (61%); albuterol, 189 (59%); aspirin, 57 (18%); morphine, 20 (6%); and prehospital intubation, 15 (5%). Patients were initially hypertensive [mean +/- standard deviation of systolic blood pressure (SBP) was 167 +/-37 mm Hg], tachycardic (heart rate 106 +/- 24 beats/min), tachypneic (respiratory rate 33 +/- 7 breaths/min), and hypoxic (pulse oximetry 88% +/- 9.5%). After treatment, mean changes included decreases (95% confidence interval) in (SBP), -10.6 mm Hg (-14.1 to -7.1), heart rate, -2.3 beats/min (-4.0 to -0.7), and respiratory rate, -3.0 (-3.6 to -2.3), and an increase in oxygen saturation, +8.2 (7.1 to 9.3). Changes in blood pressure and oxygen saturation after treatment correlated with initial values. There was no independent association of either nitroglycerin, furosemide, albuterol, or morphine with improvement in vital signs.

CONCLUSION

Prehospital patients with ADHF are a heterogeneous group of patients with significant variability in vital signs. The change in systolic blood pressure or oxygen saturation after treatment depends greatly on the patient's starting point. There was no association of either nitroglycerin or other medications with the improvement in vital signs.

Buprenorphine: a primer for emergency physicians

The recent approval of office-based treatment for opioid addiction and US Food and Drug Administration approval of buprenorphine will expand treatment options for opioid addiction. Buprenorphine is classified as a partial micro opioid agonist and a weak kappa antagonist. It has a high affinity for the micro receptor, with slow dissociation resulting in a long duration of action and an analgesic potency 25 to 40 times more potent than morphine. At higher doses, its agonist effects plateau and it begins to behave more like an antagonist, limiting the maximal analgesic effect and respiratory depression. This "ceiling effect" confers a high safety profile clinically, a low level of physical dependence, and only mild withdrawal symptoms on cessation after prolonged administration. Suboxone contains a mixture of buprenorphine and naloxone. The naloxone is poorly absorbed sublingually and is designed to discourage intravenous use. Subutex, buprenorphine only, will also be available primarily as an initial test dose. Clinicians will be using this drug for detoxification or for maintenance of opioid addiction. Patients with recent illicit opioid use may develop a mild precipitated withdrawal syndrome with the induction of buprenorphine. Acute buprenorphine intoxication may present with some diffuse mild mental status changes, mild to minimal respiratory depression, small but not pinpoint pupils, and relatively normal vital signs. Naloxone may improve respiratory depression but will have limited effect on other symptoms. Patients with significant symptoms related to buprenorphine should be admitted to the hospital for observation because symptoms will persist for 12 to 24 hours.

Gamma-hydroxybutyrate serum levels and clinical syndrome after severe overdose

STUDY OBJECTIVE

We discuss a prospective case series of patients who present with a severe gamma-hydroxybutyrate intoxication with confirmatory serum and urine gamma-hydroxybutyrate levels.

METHODS

Patients with a clinical suspicion of gamma-hydroxybutyrate-like drug overdoses and a Glasgow Coma Scale score of 8 or lower were identified from July 1998 through January 1999. Serial serum specimens and a single urine specimen were collected. The levels of gamma-hydroxybutyrate were performed by gas chromatography-mass spectrometry.

RESULTS

All 16 suspected severe gamma-hydroxybutyrate overdose patients had significant serum or urine levels of gamma-hydroxybutyrate. Serum levels ranged from 45 to 295 mg/L, with a median of 180 mg/L (interquartile range [IQR] 235 to 118 mg/L). Patients who developed a Glasgow Coma Scale score of 3 had serum levels that ranged from 72 to 300 mg/L, with a median of 193 mg/L (IQR 242 to 124 mg/L). The time of awakening ranged from 30 minutes to 190 minutes, with a median of 120 minutes (IQR 150 to 83 minutes). Quantitative serum gamma-hydroxybutyrate levels did not correlate with the degree of coma or the time to awakening. Urine levels ranged from 432 to 2,407 mg/L, with a median of 1,263 mg/L (IQR 1,550 to 796 mg/L). Mild transitory hypoventilation occurred in 5 of the 16 patients.

CONCLUSION

All of our patients with clinically suspected severe gamma-hydroxybutyrate overdose were confirmed to have significant serum and urine levels of exogenous gamma-hydroxybutyrate. They presented with severe coma that lasted 1 to 2 hours. Transient hypoventilation occurred in one third of these patients.

Heroin-related noncardiogenic pulmonary edema : a case series

STUDY OBJECTIVES

To examine the current clinical spectrum of noncardiogenic pulmonary edema (NCPE) related to heroin overdose.

DESIGN

Retrospective chart review of all identified patients from August 1994 through December 1998.

SETTING

Urban academic hospital.

PATIENTS OR PARTICIPANTS

Heroin-related NCPE was defined as the syndrome in which a patient develops significant hypoxia (room air saturation < 90% with a respiratory rate > 12/min) within 24 h of a clinically apparent heroin overdose. This should be accompanied by radiographic evidence of diffuse pulmonary infiltrates not attributable to other causes, such as cardiac dysfunction, pneumonia, pulmonary embolism, or bronchospasm, and which resolve clinically and radiographically within 48 h.

INTERVENTIONS

None.

MEASUREMENTS AND RESULTS

Twenty-seven patients were identified during this 53-month period, with a majority being male patients (85%; average age, 34 years). Twenty patients (74%) were hypoxic on emergency department arrival, and 6 patients (22%) had symptoms develop within the first hour. One patient had significant hypoxia develop within 4 h. Nine patients (33%) required mechanical ventilation, and all intubated patients but one were extubated within 24 h. Eighteen patients (66%) were treated with supplemental oxygen alone. Hypoxia resolved spontaneously within 24 h in 74% of patients, with the rest (22%) resolving within 48 h. Twenty patients (74%) had classical radiograph findings of bilateral fluffy infiltrates, but unilateral pulmonary edema occurred in four patients (15%) and more localized disease occurred in two patients (7%).

CONCLUSION

NCPE is an infrequent complication of a heroin overdose. The clinical symptoms of NCPE are clinically apparent either immediately or within 4 h of the overdose. Mechanical ventilation is necessary in only 39% of patients. The incidence of NCPE related to heroin overdose has decreased substantially in the last few decades.

Acute heroin overdose

Acute heroin overdose is a common daily experience in the urban and suburban United States and accounts for many preventable deaths. Heroin acts as a pro-drug that allows rapid and complete central nervous system absorption; this accounts for the drug's euphoric and toxic effects. The heroin overdose syndrome (sensitivity for diagnosing heroin overdose, 92%; specificity, 76%) consists of abnormal mental status, substantially decreased respiration, and miotic pupils. The response of naloxone does not improve the sensitivity of this diagnosis. Most overdoses occur at home in the company of others and are more common in the setting of other drugs. Heroin-related deaths are strongly associated with use of alcohol or other drugs. Patients with clinically significant respiratory compromise need treatment, which includes airway management and intravenous or subcutaneous naloxone. Hospital observation for several hours is necessary for recurrence of hypoventilation or other complications. About 3% to 7% of treated patients require hospital admission for pneumonia, noncardiogenic pulmonary edema, or other complications. Methadone maintenance is an effective preventive measure, and others strategies should be studied.

Clinical course of gamma-hydroxybutyrate overdose

STUDY OBJECTIVE

To describe the clinical characteristics and course of gamma-hydroxybutyrate (GHB) overdose.

METHODS

We assembled a retrospective series of all cases of GHB ingestion see in an urban public-hospital emergency department and entered in a computerized database January 1993 through December 1996. From these cases we extracted demographic information, concurrent drug use, vital signs, Glasgow Coma Scale (GCS) score, laboratory values, and clinical course.

RESULTS

Sixty-one (69%) of the 88 patients were male. The mean age was 28 years. Thirty-four cases (39%) involved coingestion of ethanol, and 25 (28%) involved coingestion of another drug, most commonly amphetamines. Twenty-five cases (28%) had a GCS score of 3, and 28 (33%) had scores ranging from 4 through 8. The mean time to regained consciousness from initial presentation among nonintubated patients with an initial GCS of 13 or less was 146 minutes (range, 16-389). Twenty-two patients (31%) had an initial temperature of 35 degrees C or less. Thirty-two (36%) had asymptomatic bradycardia; in 29 of these cases, the initial GCS score was 8 or less. Ten patients (11%) presented with hypotension (systolic blood pressure < or = 90 mm Hg); 6 of these patients also demonstrated concurrent bradycardia. Arterial blood gases were measured in 30 patients; 21 had a PCO2 of 45 or greater, with pH ranging from 7.24 to 7.34, consistent with mild acute respiratory acidosis. Twenty-six patients (30%) had an episode of emesis; in 22 of these cases, the initial GCS was 8 or less.

CONCLUSION

In our study population, patients who overdosed on GHB presented with a markedly decreased level of consciousness. Coingestion of ethanol or other drugs is common, as are bradycardia, hypothermia, respiratory acidosis, and emesis. Hypotension occurs occasionally. Patients typically regain consciousness spontaneously within 5 hours of the ingestion.