Wilderness Medical Society Clinical Practice Guidelines for the Out-of-Hospital Evaluation and Treatment of Accidental Hypothermia: 2019 Update.

To provide guidance to clinicians, the Wilderness Medical Society convened an expert panel to develop evidence-based guidelines for the out-of-hospital evaluation and treatment of victims of accidental hypothermia. The guidelines present the main diagnostic and therapeutic modalities and provide recommendations for the management of hypothermic patients. The panel graded the recommendations based on the quality of supporting evidence and a balance between benefits and risks/burdens according to the criteria published by the American College of Chest Physicians. The guidelines also provide suggested general approaches to the evaluation and treatment of accidental hypothermia that incorporate specific recommendations. This is the 2019 update of the Wilderness Medical Society Practice Guidelines for the Out-of-Hospital Evaluation and Treatment of Accidental Hypothermia: 2014 Update.

Wilderness Medical Society practice guidelines for the out-of-hospital evaluation and treatment of accidental hypothermia: 2014 update.

To provide guidance to clinicians, the Wilderness Medical Society (WMS) convened an expert panel to develop evidence-based guidelines for the out-of-hospital evaluation and treatment of victims of accidental hypothermia. The guidelines present the main diagnostic and therapeutic modalities and provide recommendations for the management of hypothermic patients. The panel graded the recommendations based on the quality of supporting evidence and the balance between benefits and risks/burdens according the criteria published by the American College of Chest Physicians. The guidelines also provide suggested general approaches to the evaluation and treatment of accidental hypothermia that incorporate specific recommendations. This is an updated version of the original Wilderness Medical Society Practice Guidelines for the Out-of-Hospital Evaluation and Treatment of Accidental Hypothermia published in Wilderness & Environmental Medicine 2014;25(4):425-445.

Wilderness Medical Society practice guidelines for the out-of-hospital evaluation and treatment of accidental hypothermia.

To provide guidance to clinicians, the Wilderness Medical Society (WMS) convened an expert panel to develop evidence-based guidelines for the out-of-hospital evaluation and treatment of victims of accidental hypothermia. The guidelines present the main diagnostic and therapeutic modalities and provide recommendations for the management of hypothermic patients. The panel graded the recommendations based on the quality of supporting evidence and the balance between benefits and risks/burdens according the criteria published by the American College of Chest Physicians. The guidelines also provide suggested general approaches to the evaluation and treatment of accidental hypothermia that incorporate specific recommendations.

Percutaneous transtracheal ventilation: resuscitation bags do not provide adequate ventilation.

INTRODUCTION: Percutaneous, transtracheal jet ventilation (PTJV) is an effective way to ventilate both adults and children. However, some authors suggest that a resuscitation bag can be utilized to ventilate through a cannula placed into the trachea. HYPOTHESIS: Percutaneous transtracheal ventilation (PTV) through a 14-gauge catheter is ineffective when attempted using a resuscitation bag. METHODS: Eight insufflation methods were studied. A 14-gauge intravenous catheter was attached to an adult resuscitation bag, a pediatric resuscitation bag, wall-source (wall) oxygen, portable-tank oxygen with a regulator, and a jet ventilator (JV) at two flow rates. The resuscitation bags were connected to the 14-gauge catheter using a 7 mm adult endotracheal tube adaptor connected to a 3 cc syringe barrel. The wall and tank oxygen were connected to the 14-gauge catheter using a three-way stopcock. The wall oxygen was tested with the regulator set at 15 liters per minute (LPM) and with the regulator wide open. The tank was tested with the regulator set at 15 and 25 LPM. The JV was connected directly to the 14-gauge catheter using JV tubing supplied by the manufacturer. Flow was measured using an Ohmeda 5420 Volume Monitor. A total of 30 measurements were taken, each during four seconds of insufflation, and the results averaged (milliliters (ml) per second (sec)) for each device. RESULTS: Flow rates obtained using both resuscitation bags, tank oxygen, and regulated wall oxygen were extremely low (adult 215 +/- 20 ml/sec; pediatric 195 +/- 19 ml/sec; tank 358 +/- 13 ml/sec; wall at 15 l/min 346 +/- 20 ml/sec). Flow rates of 1,394 +/- 13 ml were obtained using wall oxygen with the regulator wide open. Using the JV with the regulator set at 50 pounds per square inch (psi), a flow rate of 1,759 +/- 40 was obtained. These were the only two methods that produced flow rates high enough to provide an adequate tidal volume to an adult. CONCLUSIONS: Resuscitation bags should not be used to ventilate adult patients through a 14-gauge, transtracheal catheter. Jet ventilation is needed when percutaneous transtracheal ventilation is attempted. If jet ventilation is attempted using oxygen supply tubing, it must be connected to an unregulated oxygen source of at least 50 psi.

Hypothermia with profound anemia and pancreatitis.

A patient with severe hypothermia presented with an initial rectal temperature of 28.3 degrees C coupled with a hemoglobin of 2.2 g x dL(-1) and acute pancreatitis. Although hypothermia decreases oxygen and substrate consumption by tissues and can be cerebro-protective, the ideal rewarming strategy is unclear when the oxygen-delivery system is profoundly deficient, as with severe anemia. In this patient, truncal active external rewarming with a forced-air system, heated inhalation, and slow warmed transfusion yielded a 1.5 degrees C x h(-1) rate of rewarming and a good outcome. We discuss the numerous protective and detrimental factors affecting oxygenation and ventilation during hypothermia coupled with profound anemia and the possible etiologic explanations for coexistent hypothermia and pancreatitis.