Search

Exposures to hydrazines occur during aeronautic and space operations and pose a potential risk to personnel. Historically, extensive preparatory countermeasures have been taken due to concern for severe toxicity. This study seeks to better understand manifestations of acute occupational exposures to hydrazine to guide recommendations for management. A retrospective database review of records from four United States regional poison centers was conducted of all human exposures to hydrazine, monomethylhydrazine, or 1,1-dimethylhydrazine over two decades. Following case abstraction, descriptive statistics were performed to characterize demographics, manifestations, treatments, and outcomes. One hundred and thirty-five cases were identified, and most were adult males exposed to inhaled hydrazine propellant vapors. Fifty-seven percent of patients were asymptomatic following exposure; otherwise, common symptoms were dyspnea, throat irritation, cough, ocular irritation, and headache. All patients were evacuated or received decontamination, with a few reports of symptomatic treatments, including oxygen supplementation and salbutamol (albuterol). Patients usually recovered quickly and were released after a brief healthcare facility evaluation or observed locally. No patients developed delayed symptoms. Symptoms of severe toxicity were not observed, and there were no deaths. Acute exposures to hydrazines during operations within the aerospace industry appear to be limited primarily to mucosal and mild pulmonary irritation without significant neurologic, hepatic, or hematologic toxicity. These findings are contrary to previously established expectations and may be related to low-level exposures or possibly due to current emergency countermeasures. Care in occupational hydrazine exposure will focus on evacuation, decontamination, and symptomatic management of chemical irritant properties of hydrazines. It is reasonable to manage mild cases outside of a healthcare facility. Continued endeavors in human space exploration and habitation will increase the risk of these exposures, making it imperative that clinicians be comfortable with the care and management of these patients. [ABSTRACT FROM AUTHOR]

Objectives: Hydrazine (HZ) and Hydrazine Derivative (HZ-D) exposures pose health risks to people in industrial and aerospace settings. Several recent systematic reviews and case series have highlighted common clinical presentations and management strategies. Given the low frequency at which HZ and HZ-D exposures occur, a strong evidence base on which to develop an evidence-based guideline does not exist at this time. Therefore, the aim of this project is to establish a consensus guideline for prehospital care of patients with exposures to HZ and HZ-Ds., Methods: A modified Delphi technique was used to develop clinical questions, obtain expert panel opinions, develop initial patient care recommendations, and revise the draft into a final consensus guideline. First, individuals (Emergency Medical Services (EMS) physicians and hazardous materials technicians) with experience in management of HZ and HZ-Ds identified relevant clinical questions. An expert panel was then convened to make clinical recommendations. In the first round, the panel voted on clinical care recommendations. These recommendations were drafted into a guideline that expert panel members reviewed. After review, additional unanswered questions were discussed electronically by expert panel members, and electronic votes were cast. Ultimately, patient care recommendations were condensed into a concise, consensus guideline., Results: Eight clinical questions regarding treatment of patients with HZ and HZ-D exposures were identified. These questions were reviewed by the expert panel which included 2 representatives from: aerospace medicine, military medicine, EMS medicine, paramedicine, pharmacy, and toxicology. Draft patient care recommendations generated three additional questions which were discussed electronically and voted on. These recommendations were then formatted into a guideline outlining recommendations for care prior to decontamination, during decontamination, and after decontamination., Conclusions: The consensus guideline for clinical care of patients with exposure to HZ/HZ-Ds is as follows: Prior to decontamination, use appropriate personal protective equipment, and when necessary, support ventilation using a bag-valve-mask and administer midazolam intramuscularly for seizures. After decontamination, provide supplemental oxygen; consider selective advanced airway management when indicated; administer inhaled beta-agonists for wheezing; and, for seizures unresponsive to multiple doses of benzodiazepines that occur during pre-planned, high-hazard activities, such as spacecraft recovery, consider intravenous or intraosseous pyridoxine.