A prospective, multi-year analysis of illness and injury during summer travel to arid environments.

OBJECTIVE: There exist no prospectively generated analyses of the type and frequency of medical incidents in desert settings. We created a database of every illness and injury during 6 field seasons in the Gobi Desert in order to optimize expedition medical and safety planning. METHODS: Every incident presenting to the expeditions' physicians, regardless of type, magnitude, treatment, or outcome, was recorded. Incidents ranged from headache, insomnia, and diarrhea to lacerations, infection, fights, psychosis, and foreign body extraction and were thus categorized, segregating urban travel-related complaints from illness and injury occurring in the desert setting. The chronology of incidents and illnesses was observed. The incidence of categorized illness and injury was analyzed using descriptive statistics and was presented in terms of person-days in the field. RESULTS: There were 412 incidents recorded during 2689 person-days from 6 field seasons in the Gobi Desert from 2003 through 2007. The expeditions' physicians saw an average of 2.2 incidents x d(-1) in the urban setting compared to 3.6 incidents x d(-1) in the desert. Circadian rhythm disturbances, gastrointestinal illnesses, and musculoskeletal complaints predominated in the urban setting, while minor trauma, heat-related exposures, and gastrointestinal and orthopedic problems predominated in the desert setting. Our data show an absolute risk of illness or injury of 153.2 incidents per 1000 person-days and a risk of "gastrointestinal" and "trauma" complaints of 21.2 and 23.1 per 1000 person-days, respectively. CONCLUSIONS: Herein we describe results from the first ever prospective study of the hazards of travel in an arid environment. We observed that there are patterns of injury and illness that are consistent across expeditions to the Gobi Desert. For example, while heat- and wind-exposure-related illness and injury in the desert are quite common, other aspects of the desert environment are very forgiving. Perhaps the most interesting finding in our cohort was the degree to which different problems occurred at different stages of the expeditions. Our data sets suggest several future studies to evaluate patterns of illness and injury and could be an asset to recreational travelers and religious pilgrims, as well as to those sending employees to extreme environments.

In vitro-activated charcoal binding of staphylococcal enterotoxin B.

OBJECTIVE: Staphylococcal enterotoxin B (SEB) is a CDC category B bioterror agent that may cause significant morbidity. We assessed the in vitro binding of SEB by activated charcoal (AC). METHODS: Aqueous solutions of SEB at three concentrations (0.4, 2 and 10 mcg/mL) were combined in volume rations of 3:1, 6:1, and 12:1 with AC at three concentrations (62.5, 125, and 250 mg/mL) or left untreated as control samples. Subsequently, each sample was tested with a qualitative SEB immunoassay to detect the presence of SEB at concentrations of >12.5 ng/mL. RESULTS: SEB was detectable in each untreated control solution. SEB was undetectable in the 2 mcg/mL and 0.4 mcg/mL solutions after treatment with AC in all quantities. SEB was detected in the 10 mcg/mL solution after combination with all three concentrations of AC. The difference in assay results between charcoal treated and untreated pairs was statistically significant. CONCLUSION: At ratios of 3:1 and above, SEB was adsorbed by AC when combined in the manner described in concentrations of 2 mcg/mL and 0.4 mg/mL. In a quantity of 10 mcg/mL complete charcoal binding of SEB did not occur with any ratio of AC used. These results support a role for AC in treating patients exposed to SEB or purifying liquids or gases containing SEB.

Practicing paramedics cannot generate or estimate safe endotracheal tube cuff pressure using standard techniques.

OBJECTIVES: We sought to determine the ability of paramedics to inflate endotracheal tube cuffs within safe pressure limits as well as to estimate the pressure of previously inflated endotracheal tube cuffs by palpation of the pilot balloon. METHODS: Using a tracheal simulation model, we conducted a prospective, observational, cross-sectional simulation study of licensed, practicing paramedics. This included evaluation of their ability to inflate the cuff of an endotracheal tube to a safe pressure, defined as < or = 25 cm H(2)O, as well as to identify excessive intracuff pressure in previously inflated ETT cuffs by palpation of the pilot balloon. RESULTS: Fifty-three paramedics were sampled. The average pressure generated by inflating the endotracheal tube cuff was > 108 cm H(2)O. Participants were only 13% sensitive detecting over inflated endotracheal tube cuffs (95% CI 7.3-17.8). CONCLUSIONS: Participants were unable to inflate endotracheal tube cuff to safe pressures and were unable to identify endotracheal tube cuffs with excessive intracuff pressure by palpation. Clinicians should consider using devices such as manometers to facilitate safe inflation and accurate measurement of endotracheal tube cuff pressure.

Humming is as effective as Valsalva's maneuver and Trendelenburg's position for ultrasonographic visualization of the jugular venous system and common femoral veins.

STUDY OBJECTIVE: The purpose of this study is to compare ultrasonographic visualization of the jugular and common femoral veins by using a novel technique (humming) and 2 conventional techniques (Valsalva's maneuver and Trendelenburg's position). The Valsalva's maneuver and Trendelenburg's position are common methods for producing venous distention, aiding ultrasonographically guided identification and cannulation of the jugular and common femoral veins. We hypothesize that humming is as effective as either Valsalva's maneuver or Trendelenburg's position for distention and ultrasonographic visualization of these procedurally important blood vessels. Herein, we investigate a new method of venous distension that may aid in the placement of central venous catheters by ultrasonographic guidance. METHODS: Healthy, normal volunteers aged 28 to 67 years were enrolled. Each subject's internal jugular, external jugular, and common femoral veins were measured in cross-section by ultrasonograph during rest (baseline), humming, Valsalva's maneuver, and Trendelenburg's position. Three measurements were recorded per observation in each position. Subjects were used as their own controls, and measurements were normalized to percentage increase in diameter during each maneuver or position for later comparison. RESULTS: The study population consisted of 7 subjects, with a mean age of 47 years. Cross-sectional area was calculated for each vessel in 3 groups: baseline/control, Valsalva, Trendelenburg, and humming. The mean percentage change (+/-SD) relative to baseline cross-sectional area of the jugular vessels for each subject were external jugular vein: humming 134%+/-25% (95% confidence interval [CI] 124.9% to 146.9%), Valsalva 136%+/-23% (95% CI 121.3% to 147.5%), Trendelenburg 137%+/-32% (95% CI 120.7% to 156.9%); internal jugular vein: humming 137%+/-27% (95% CI 119.4% to 148.2%), Valsalva 139%+/-24% (95% CI 122.4% to 148.7%), Trendelenburg 141%+/-35% (95% CI 116.5% to 156.5%); common femoral vein: humming 131%+/-15% (95% CI 120.4% to 139.1%), Valsalva 139%+/-18% (95% CI 127.9% to 150.4%), Trendelenburg 132%+/-24% (95% CI 113.3% to 142.9%). CONCLUSION: All 3 maneuvers distended the external jugular, internal jugular, and common femoral veins compared to baseline. There was no important difference in magnitude of cross-sectional area between any of the 3 maneuvers when compared with one another. Humming shares many physiologic similarities to Valsalva's maneuver and may be more familiar and easier to perform during procedures such as ultrasonographically guided central venous catheter placement and insertion of external jugular intravenous catheters.

Hemodynamic effects of intravenous fat emulsion in an animal model of severe verapamil toxicity resuscitated with atropine, calcium, and saline.

BACKGROUND: Intravenous fat emulsion (IFE) decreases cardiotoxicity from several lipid-soluble drugs, including verapamil. OBJECTIVES: To verify if the addition of IFE to the standard treatment of severe verapamil toxicity would improve hemodynamics and survival. METHODS: Fourteen dogs were instrumented to measure systolic blood pressure, diastolic blood pressure, mean arterial pressure (MAP), heart rate, cardiac output, central venous pressures, left ventricular pressure changes over time, mixed venous oxygen saturation, pH, and base excess. Verapamil toxicity, defined as a 50% decrease in MAP, was induced with verapamil at 6 mg/kg/hr and maintained for 30 minutes by titrating the verapamil infusion rate. Following verapamil toxicity, the verapamil infusion rate was changed to 2 mg/kg/hr and continued for 90 minutes. All dogs were resuscitated with atropine (0.04 mg/kg intravenously) and calcium chloride (15 mg/kg intravenously every 5 minutes for three doses) and then randomized to receive either IFE (7 mg/kg of 20%) intravenously or equivalent volumes of 0.9% normal saline over 30 minutes. Measurements were recorded for 120 minutes by investigators blinded to the treatment. Data were analyzed using analysis of variance, survival analysis, and log-rank test. RESULTS: Before the 30-minute IFE or normal saline infusion, there were no differences in hemodynamic parameters. After IFE or normal saline infusion, the IFE-treated group had higher MAP at 30 minutes (95% confidence interval [CI] = 5.6 to 44.7 mm Hg), 45 minutes (95% CI = 10.8 to 50.0 mm Hg), and 60 minutes (95% CI = 10.2 to 53.1 mm Hg). Kaplan-Meier 120-minute survival rate was 14% (95% CI = 0.5% to 53%) for the saline group as compared with 100% (95% CI = 59% to 100%) for the IFE group (p = 0.01). CONCLUSIONS: Standard resuscitation and IFE increase MAP and survival in an animal model of severe verapamil toxicity compared with standard resuscitation alone.

Experienced emergency medicine physicians cannot safely inflate or estimate endotracheal tube cuff pressure using standard techniques.

OBJECTIVE: Tracheal necrosis, stenosis, and rupture may result from overinflated endotracheal tube cuffs (ETTcs). We sought to determine the ability of faculty emergency medicine (EM) physicians to safely inflate ETTc as well as to estimate pressure of previously inflated ETTc. METHODS: Using a previously tested tracheal simulation model, we assessed EM physician inflation of ETTc pilot balloons. Participants also palpated the pilot balloon of 9 ETTc inflated to pressures ranging from extremely low to extremely high in a random order and reported their estimate of pressure. RESULTS: We sampled 41 faculty EM physicians from 5 EM residency programs. Using palpation, participants were only 22% sensitive detecting overinflated ETTc. The average ETTc pressure produced by inflation was more than 93 cm H(2)O (normal, 15-25 cm H(2)O). CONCLUSIONS: Participants were unable to inflate ETTc to safe pressures or estimate pressure of ETTc by palpation. Clinicians should consider using devices to facilitate safe inflation and accurate measurement of ETTc pressure.

A case of glaucomatocyclitic crisis in the emergency department.

Glaucomatocyclitic crisis is caused by an idiopathic inflammatory process of the trabecular meshwork, causing a decrease in aqueous outflow. This decrease causes the cyclitis-associated ocular hypertension. There is rarely any pain or other findings typically associated with glaucoma. Thus, the diagnosis is easily missed. Patients may present with nonspecific symptoms such as blurry vision or periorbital discomfort. Examination typically reveals a noninjected, slightly mydriatic eye. Slit-lamp examination may reveal fewer-than-expected inflammatory cells in the anterior chamber, with only occasional small nonpigmented keratic precipitates on the corneal epithelium. The intraocular pressure is typically increased (30 to 70 mm Hg), despite an open angle. Therapy is aimed at controlling the increased intraocular pressure with the use of topical imidazolines, beta-blockers, and carbonic anhydrase inhibitors. Complications related to prolonged and recurrent attacks of increased intraocular pressure may result in damage to the optic nerve head and visual field compromise.

Contrast CT scan fails to detect the last heroin packet.

We report on the comparative utility of the abdominal computed tomography (CT) scan and contrast-enhanced plain radiography in one case of a "body packer" who claimed to have passed 50 out of 55 packets before being brought to the Emergency Department by the police for further gastrointestinal decontamination. The presence of retained packets was confirmed by plain radiography. The patient received whole bowel irrigation (WBI) with polyethylene glycol electrolyte solution (PEG-ELS) and passed four more packets. A helical abdominal CT scan with oral contrast was performed to identify any residual packets. A negative CT scan and a reliable patient prompted a subsequent upright abdominal radiograph that showed the last packet in the right lower quadrant. This packet ultimately passed with continued WBI. This case illustrates the failure of CT scan to identify the last packet and suggests that multiple modalities may be necessary to fully confirm a therapeutic endpoint.

EMLA-induced methemoglobinemia and systemic topical anesthetic toxicity.

This case report illustrates an adult presenting with the simultaneous occurrence of both methemoglobinemia (MetHb) and systemic toxicity from the topical application of local anesthetics while undergoing laser epilation therapy of the legs. The concurrent development of both is considered uncommon in this setting and may have been related to several factors, including her recent previous treatment, increased absorption secondary to abraded skin with the addition of occlusive dressing, and possible alteration of protein binding and drug metabolism due to the use of medications. The clinical manifestations and mechanisms of MetHb and systemic local anesthetic toxicity are discussed.