Richard Gerkin

Characterization of Firefighter Exposures During Fire Overhaul

Previous studies have characterized firefighter exposures during fire suppression. However, minimal information is available regarding firefighter exposures during overhaul, when firefighters look for hidden fire inside attics, ceilings, and walls, often without respiratory protection. A comprehensive air monitoring study was conducted to characterize City of Phoenix firefighter exposures during the overhaul phase of 25 structure fires. Personal samples were collected for aldehydes; benzene; toluene; ethyl benzene; xylene; hydrochloric acid; polynuclear aromatic hydrocarbons (PNA); respirable dust; and hydrogen cyanide (HCN). Gas analyzers were employed to continuously monitor carbon monoxide (CO), HCN, nitrogen dioxide (NO2), and sulfur dioxide (SO2). Area samples were collected for asbestos, metals (Cd, Cr, Pb), and total dust. During overhaul the following exceeded published ceiling values: acrolein (American Conference of Governmental Industrial Hygienists [ACGIH] 0.1 ppm) at 1 fire; CO (National Institute for Occupational Safety and Health [NIOSH] 200 ppm) at 5 fires; formaldehyde (NIOSH 0.1 ppm) at 22 fires; and glutaraldehyde (ACGIH 0.05 ppm) at 5 fires. In addition, the following exceeded published short-term exposure limit values: benzene (NIOSH 1 ppm) at two fires, NO2 (NIOSH 1 ppm) at two fires, and SO2 (ACGIH 5 ppm) at five fires. On an additive effects basis, PNA concentrations exceeded the NIOSH recommended exposure limits (0.1 mg/M3) for coal tar pitch volatiles at two fires. Maximum concentrations of other sampled substances were below their respective permissible exposure limits. Initial 10-min average CO concentrations did not predict concentrations of other products of combustion. The results indicate that firefighters should use respiratory protection during overhaul. In addition, these findings suggest that CO should not be used as an indicator gas for other contaminants found in this atmosphere.

Adverse respiratory effects following overhaul in firefighters.

Overhaul is the stage in which firefighters search for and extinguish possible sources of reignition. It is common practice not to wear respiratory protection during overhaul. Fifty-one firefighters in two groups, 25 without respiratory protection and 26 wearing cartridge respirators, were monitored for exposure to products of combustion and changes in spirometric measurements and lung permeability following overhaul of a structural fire. Testing at baseline and 1 hour after overhaul included forced vital capacity (FVC), forced expiratory volume in one second (FEV1), serum Clara cell protein (CC16), and serum surfactant-associated protein A (SP-A). Overhaul increased CC16 in both groups, indicating increased alveolar-capillary membrane permeability. Contrary to expectations, SP-A increased and FVC and FEV1 decreased in the firefighters wearing cartridge respirators. Changes in FEV1, CC16, and SP-A were associated with concentrations of specific products of combustion or carboxyhemoglobin levels. Firefighter exposures during overhaul have the potential to cause changes in spirometric measurements and lung permeability, and self-contained breathing apparatus should be worn during overhaul to prevent lung injury.

Results of a protocol for the management of patients with fulminant liver failure

Objective:To assess the safety and efficacy of a protocol to support management of intracerebral pressure in patients with fulminant liver failure (FLF). Design and Setting:A prospective series was conducted between May 2004 and September 2006 at Banner Good Samaritan Medical Center, a 650-bed teaching hospital in Phoenix, Arizona. Patients:We recruited consecutive patients with FLF and stage 3 or 4 encephalopathy. Interventions:We placed an intracranial pressure monitor in each patient and employed a protocol to support decisions regarding hemostatic management and prevention and treatment of intracranial hypertension (IHTN). Treatment modalities included hypothermia, hypocarbia, intravenous pentobarbital, intravenous mannitol and vasopressor titration for maintenance of cerebral perfusion pressure. The main outcome measure was survival in transplant candidates. Measurements and Main Results:Twenty-two patients entered the study and 21 (95%) had at least one episode of IHTN. Eighty-two discrete episodes of IHTN occurred, and 78 of these (95%) resolved with treatment. Overall survival was 55%. Eleven of 18 (61%) of transplant candidates survived with good neurologic outcome. No patient died from isolated cerebral edema. Three patients had intracranial hemorrhages related to the intracranial pressure monitor. Conclusions:Protocol-driven management of intracranial pressure in FLF can result in good clinical outcomes in most transplant candidates, even if IHTN occurs. LEARNING OBJECTIVESOn completion of this article, the reader should be able to: Explain the most common cause of death in fulminant liver failure. Describe the protocol for management of patients with fulminant liver failure. Use this information in a clinical setting. Dr. Raschke has disclosed that he was a consultant/advisor for Cardinal Health and attended and spoke at several paid meetings and conferences in regards to intravenous heparin. The remaining authors have not disclosed any potential conflicts of interest. The authors have disclosed that the U.S. Food and Drug Administration has not approved pentobarbital for the treatment of intracranial hypertension discussed in this article. Please consult the products labeling information for approved indications and usage. All faculty and staff in a position to control the content of this CME activity have disclosed that they have no financial relationship with, or financial interests in, any commercial companies pertaining to this educational activity. Lippincott CME Institute, Inc., has identified and resolved all faculty conflicts of interest regarding this educational activity. Visit the Critical Care Medicine Web Site (www.ccmjournal.org) for information on obtaining continuing medical education credit.

Acute Cyanide Toxicity Caused by Apricot Kernel Ingestion

A 41-year-old woman ingested apricot kernels purchased at a health food store and became weak and dyspneic within 20 minutes. The patient was comatose and hypothermic on presentation but responded promptly to antidotal therapy for cyanide poisoning. She was later treated with a continuous thiosulfate infusion for persistent metabolic acidosis. This is the first reported case of cyanide toxicity from apricot kernel ingestion in the United States since 1979.

Impact of a patient care pathway protocol on surgical site infection rates in cardiothoracic surgery patients.

BACKGROUND We hypothesized that implementing a quality care initiative, including peri-incisional antibiotic administration, tight blood glucose control, and hair removal with clippers would reduce surgical site infection (SSI) rates in patients undergoing coronary artery bypass grafting (CABG), with or without valve replacement. METHODS Patients undergoing CABG were studied retrospectively, before (n = 808) and after (n = 674) instituting a patient care protocol. The pathway included peri-incisional antibiotics, tight glucose control (80 mg/dL-110 mg/dL) throughout intensive care unit (ICU) stays, and hair removal with clippers. RESULTS SSIs were significantly decreased in the experimental group (1.5%), compared with the control group (3.5%), (P = .001, odds ratio [OR] = .21). Significant independent predictors of infection included diabetes mellitus (P = .001, OR = 4.71), Nosocomial Infection Surveillance System (NNIS) wound class II (P = .044, OR = 2.07), and female gender (P = .001, OR = 2.83). CONCLUSIONS Protocols implementing timely perioperative antibiotics, tight blood glucose control, and avoidance of shaving decrease SSI rates in CABG patients.

Trauma: the impact of repeat imaging

BACKGROUND Patients referred to trauma centers often undergo an extensive diagnostic work-up before transfer. The purpose of our study was to quantify and examine the effects of repeat imaging in this population. METHODS A prospective cohort study of 410 patient transfers was performed. Repeat imaging was conducted at the discretion of the accepting surgeon for multiple reasons. Two groups were compared, those who did and those who did not require repeat imaging. RESULTS Overall, 53% of referrals received repeat imaging, at an average cost of

Efficacy of Vestibular Rehabilitation Therapy in Reducing Falls

2,985 per patient. This group was older (42 vs 37 y; P < .05), more severely injured (injury severity score, 12 vs 9; P < .05), and experienced longer delays before transfer (244 vs 192 min; P < .05). By using logistic regression analysis, injury severity score was found to be an independent predictor of the need for repeat imaging (P = .003). CONCLUSIONS Severely injured trauma patients often receive films that ultimately require duplication, resulting in transfer delay, unnecessary morbidity, and increased resource use. Targeted education and development of centralized radiology systems could alleviate some of the burden of unnecessary imaging.

First-order elimination kinetics following baclofen overdose

OBJECTIVE: To assess the short-term effectiveness of vestibular rehabilitation therapy in reducing fall risk in an at-risk population. STUDY DESIGN AND SETTING: Retrospective chart review of 70 patients older than 50 years of age at risk for falls treated at a tertiary vestibular therapy center. Fall risk was assessed by the Berg balance test. RESULTS: Vestibular rehabilitation therapy resulted in a statistically significant improvement in Berg balance test scores (pretherapy, 36.8, to posttherapy, 46.4). Referring diagnosis, age, and gender had no impact on outcome. CONCLUSION: Vestibular rehabilitation therapy significantly reduces the risk of falls in elderly at-risk patients with improvement measured at the termination of therapy. SIGNIFICANCE: Vestibular rehabilitation therapy plays an important preventive role in reducing falls in at-risk elderly patients, with beneficial effects seen at termination of therapy.

Improving Clinical Interpretation of the Anti-Platelet Factor 4/Heparin Enzyme-Linked Immunosorbent Assay for the Diagnosis of Heparin-Induced Thrombocytopenia Through the Use of Receiver Operating Characteristic Analysis, Stratum-Specific Likelihood Ratios, and Bayes Theorem

We followed serial plasma baclofen concentrations in a woman who ingested more than 2 g of baclofen in a suicide attempt, the largest ingestion of baclofen reported to date. The plasma clearance of baclofen was characterized by first-order elimination kinetics with a half-life of 8.6 hours. The persistent central nervous system depression noted in our patient after the return of plasma baclofen levels to the therapeutic range is best explained by delayed clearance of baclofen from the CNS. She made a full recovery with supportive care. No evidence of saturable elimination kinetics was found.

Vibration With the Canalith Repositioning Maneuver: A Prospective Randomized Study to Determine Efficacy

BACKGROUND Heparin-induced thrombocytopenia (HIT) is diagnosed using clinical criteria and detection of platelet-activating anti-platelet factor 4/heparin (anti-PF4/H) antibodies, usually through a surrogate enzyme-linked immunosorbent assay (ELISA). The high false-positive rate (FPR) of this ELISA prompted us to reexamine its interpretation. METHODS We analyzed anti-PF4/H ELISA results from a previously published dataset of 1,958 patients, using clinical suspicion and serotonin-release assay (SRA) to diagnose HIT. We performed receiver operating characteristic (ROC) analysis using stratum-specific likelihood ratios (SSLRs) and used Bayes theorem to construct a clinical decision-support algorithm. RESULTS The most discriminant single cutoff by anti-PF4/H ELISA for the diagnosis of HIT was found to be 0.8 optical density (OD) units, not 0.4 OD (currently accepted practice). This change reduced the FPR from 31% to 6% (95% CI, 5%-8%). ELISA results were grouped into five strata, which yielded SSLRs ranging from 0.02 (strongly ruling HIT out) to 104.4 (strongly ruling HIT in). Comparison of ROC curves demonstrated that this five-strata approach is statistically more accurate than current accepted practice at discriminating whether patients have HIT or not (area under the ROC curve, 0.97 [95% CI, 0.93-1.00] vs 0.83 [95% CI, 0.80-0.89]). Our decision-support algorithm incorporated clinical assessment into this stratified model and clarified HIT diagnosis with a high degree of certainty and without the need for SRA testing in approximately 90% of patients. CONCLUSIONS Diagnostic accuracy of the anti-PF4/H ELISA can be optimized by using a higher cutoff and a stratified interpretation of the results. Our algorithm should significantly reduce overdiagnosis of HIT and the need for SRA testing.