Measurement of end-tidal carbon dioxide in spontaneously breathing patients in the pre-hospital setting. A prospective evaluation of 350 patients.

OBJECTIVE: Monitoring of end-tidal carbon dioxide (EtCO(2)) is good clinical practice in the patient who is intubated and ventilated. This study investigated the EtCO(2) values in spontaneously breathing patients treated in a physician-staffed mobile intensive care unit (MICU). This article also discusses whether EtCO(2) monitoring may have an influence on therapeutic decisions by emergency physicians by providing additional information. METHODS: Over a period of 6 months, 350 spontaneously breathing patients (162 males, 137 females) were treated and transported in our MICU and monitored using a LifePak 12 monitor (EtCO(2), respiratory rate, pO(2), blood pressure, heart rate). Only 299 were enrolled in the study. RESULTS: Pathological EtCO(2) values were detected in 19 patients (6.3%). EtCO(2) levels of >55 mmHg (7.3 kPa) were found in nine of 12 (75%) patients with asthma, in one of 23 patients with hypoglycaemia (4.3%), and in all patients with subarachnoid hemorrhage, acute seizures and drug intoxications. With the exception of the asthma patients, all patients had an initial Glasgow Coma Score <8. EtCO(2) levels <20 mmHg (2.7 kPa) were found in all patients with hyperventilation or shock due to volume deficiency. Errors in EtCO(2) measurement occurred in 5% of cases. CONCLUSION: Although EtCO(2) monitoring may be a useful additional variable in spontaneously breathing patients. Consideration of the respective disease and the cost to benefit ratio suggests that this method should only be used for selected indications.

Metabolic effects of metaproterenol overdose: hypokalemia, hyperglycemia and hyperlactatemia.

This case report of metaproterenol toxicity was associated with hypokalemia, hyperglycemia and hyperlactatemia. A similar triad has been reported in acute theophylline poisoning. Hypokalemia and hyperglycemia have been reported with other beta-agonists, but not metaproterenol. Patients presenting with the metabolic triad of hypokalemia, hyperglycemia, and hyperlactatemia should have theophylline and beta-agonist toxicity included in their differential diagnosis because the prognosis and therapy of these 2 intoxications is markedly different.

Continuous intravenous flumazenil infusion for benzodiazepine poisoning.

This is the first US report of continuous iv flumazenil infusion for benzodiazepine poisoning. A MEDLINE search from 1966 to 1999 revealed no similar reports in the US literature. A 24-y-o woman ingested 50, 2 mg (=100 mg) flunitrazepam tablets in a suicide attempt. She presented 30 min after ingestion with a temperature of 36.5 C, blood pressure of 90/36 mmHg, pulse of 84/min, and shallow respirations of 8/min. Her Glasgow coma scale (GCS) was 8. Her ECG showed sinus rhythm at 80/min, a QRS axis of 30 with no terminal 40 msec deviation, and a QRS interval of 84 msec. She received 0.2 mg flumazenil iv and her GCS improved to 15. She was orogastrically lavaged and given 50 g of activated charcoal. Resedation to a GCS of 8 recurred twice, requiring additional 0.3 mg and 0.5 mg boluses of flumazenil iv, totaling 1.0 mg over 1 h. Then, a continuous flumazenil infusion was started at 1.0 mg/h, maintaining her GCS at 15. Fourteen h later, the continuous flumazenil infusion was terminated, resulting in resedation and clinical hypoventilation. Flumazenil infusion was restarted at 1.0 mg/h with resolution of sedation and hypoventilation. Thirty h after overdose flumazenil infusion was terminated without resedation or hypoventilation. Continuous iv flumazenil infusion is not US Food and Drug Administration approved, and further study is necessary in carefully selected patients to determine its safety and efficacy.

Trauma and thyroid-induced tachycardia.

Excluding a source of hemorrhage after blunt trauma in a patient who presents with a sustained tachycardia can be challenging. This report is of two trauma patients presenting with undiagnosed thyrotoxicosis. Trauma-triggered thyrotoxicosis is rarely reported in the literature. The confusing presentation, the laboratory analysis, and the response to therapeutic intervention are reviewed.

Spinal cord injury with a narrow spinal canal: utilizing Torg's ratio method of analyzing cervical spine radiographs.

A 65-year-old inebriated man crashed his car and presented with spinal shock and neurogenic shock from a cervical spinal cord injury without cervical spine fracture or dislocation. The lateral cervical spine radiography was initially read as normal, except for degenerative disk disease; however, Torg's ratio method of analyzing cervical spinal canal sagittal width indicated the spinal canal was congenitally narrow. Magnetic resonance imaging confirmed this and showed bulging and herniation of multiple invertebral disks between C2 and C7. This case illustrates the value of using Torg's ratio method of analyzing lateral cervical spine radiographs. Although Torg's method has not been prospectively validated, it may be useful to identify patients at risk for cervical spinal cord injuries without fractures or dislocations. An abnormal Torg's ratio may be the only clue to the fact that the patient is at higher risk of spinal cord injury when the patient's history or examination is questionable because of head injury, drug intoxication, or therapeutic sedation and paralysis.

Exotic snakebite: envenomation by an African puff adder (Bitis arietans).

We report an envenomation by the African puff adder (Bitis arietans), an exotic snake in the United States. The patient developed swelling and ecchymoses in the affected extremity, and cutaneous necrosis of the envenomated fingertip. There was no significant coagulopathy. He received 20 vials of specific antivenin (Schlangengift-Immunserum Behring Zentralafrika, Behringwerke, Marburg, Germany) and debridement of devitalized finger tissue. The only permanent sequelae were cutaneous scarring and permanent loss of the fingernail on the envenomated finger. Exotic snakebite is a rare presenting problem in emergency departments. The initial approach to a patient envenomated by an exotic venomous snake is discussed. Use of antivenin and supportive care are emphasized.

Loxosceles arizonica bite associated with shock.

Envenomation by the brown recluse spider (Loxosceles reclusa) is associated with shock, significant hemolysis, renal insufficiency, and disseminated intravascular coagulation (DIC). Shock has never been associated with envenomation by L arizonica, a related species indigenous to Arizona, southern California, and northwestern Mexico. We report the case of a 13-year-old girl, bitten by a specimen of L arizonica (the spider was identified by an entomologist), in whom shock and a typical cutaneous lesion developed. She did not experience renal insufficiency or disseminated intravascular coagulation. Infectious causes of shock were excluded. She recovered completely with supportive care.

Snakes and snakebite in Central America.

This review treats the general biology, taxonomy, distribution and venom apparatus of the venomous snakes of Central America. Consideration has been given to the chemistry, pharmacology and immunology of the venom, and particular attention is dispensed to the clinical problem, including the treatment, of envenomations by these reptiles.

Marijuana and hyperthermia.

BACKGROUND: Animal and human laboratory studies suggest marijuana may cause hyperthermia. However, there are no clinical case reports of life-threatening hyperthermia associated with use of marijuana alone. CASE REPORT: We report a patient who developed severe hyperthermia after smoking a marijuana cigarette and jogging on a warm day. He presented with delirium; hot, red, dry skin; and a rectal temperature of 41.7 degrees C. Historical and laboratory data indicated he had used cannabinoids and no other drugs. This is the first report of life-threatening hyperthermia temporally associated with use of marijuana alone.

Aortic dissection in a healthy 32-year-old man without risk factors.

We report the case of a 32-year-old male who presented to the emergency department with left-sided chest pain associated with burning epigastric discomfort and radiation to the back. Similar symptoms had prompted his visit to another emergency department 1 week earlier. He was discharged from that institution after a negative upper gastrointestinal series. In our emergency department a transoesophageal echocardiograph raised suspicion of a dissection of the thoracic aorta, which was later confirmed by a contrast chest computed tomography scan. The patient was admitted to the intensive care unit but refused surgical intervention at the time of admission. A detailed history failed to uncover any known risk factors for this disease entity. Aortic dissection is rarely seen in young, healthy individuals. Atypical clinical representations are reviewed. The emergency department work-up of aortic dissection is discussed.

Evidence for clonal disease by magnetic resonance imaging in patients with hypoplastic marrow disorders.

Some patients with hypoplastic marrow disorders, including aplastic anemia (AA), are at risk for clonal evolution to myelodysplastic syndromes (MDS) and leukemia. Magnetic resonance imaging (MRI) of marrow of the spine, pelvis, and femurs was performed in 24 patients with hypoplastic marrow disorders. In 12 patients (three AA, nine MDS) MRI was compatible with the clinical and biopsy diagnoses and served to define the spectrum of marrow patterns in these disorders. In eight patients with hypocellular marrow biopsies and a clinical diagnosis of AA, MRI showed an unexpected inhomogeneous or diffuse cellular pattern. Concurrent or subsequent marrow or cytogenetic studies have led to diagnoses of hypoplastic MDS in seven of these patients. In four patients with prolonged hypoplasia after bone marrow transplantation for lymphoma, a speckled pattern superimposed on a fatty background appeared in serial MRI studies. One case evolved to AML, two developed megaloblastic foci, and one remains hypoplastic at 19 months. This study suggests that MRI is able to detect early clonal disease in patients with AA, and can distinguish AA from hypoplastic MDS.

Congenital hip dislocation after walking age.

Between 1940 and 1970, 107 patients more than 1 year of age with 134 congenitally dislocated hips were treated at the Alfred I. duPont Institute. It was found that after initial reduction 66% of hips reduced closed and approximately 30% of hips reduced open required further surgery. Good acetabular development was seen in 19% of hips reduced between 2 and 3 years, but only in 7% reduced after 3 years of age. The best results in the correction of residual dysplasia or subluxation were seen if correction was done before 6 years of age. Avascular necrosis was highest after simple open reduction and was responsible for most of the fair and poor results, with late development of poor femoral head coverage after an initial concentric reduction with good coverage.

Congenital radial head dislocation.

Fifty patients with 77 congenitally dislocated radial heads were reviewed to assess the diagnostic features, functional limitations, symptomatology, and results of treatment. Twenty-three patients had associated anomalies of the affected upper extremity, and 35 had anomalies in other parts of the body. In six patients no other anomaly was found, all six had bilateral involvement. No patient had congenital radial head dislocation as a unilateral isolated anomaly, and therefore we doubt its existence. Functional limitation with congenital radial head dislocation is minimal and pain is uncommon. Radial head excision relieves pain and improves appearance: however, it does not increase motion.