Hypertonic saline infusion in hemorrhagic shock treated by military antishock trousers (MAST) in awake sheep

The effect of scene time on survival

A review of the literature was carried out to determine the importance of pre-hospital scene times and how it can be affected. In the UK, and certain centres in North America, mortality and morbidity in critically injured patients appears to be related to scene times. The majority of these patients only require basic life support at the scene. Consequently the possible benefits of more advanced procedure need to be compared with the transportation period, the time needed to mobilize a medical team and skill proficiency. Cardiovascular resuscitation procedures in particular require reappraisal. Though haemostasis is essential, there is little evidence to support the use of fluid resuscitation in nontrapped urban patients with a significant haemorrhage problem. In contrast patients who are not bleeding do appear to benefit from advanced life support procedures even though this increases scene time. There is therefore a need for pre-hospital paramedic workers to triage patients so that appropriate resuscitation can be carried out.

Military anti-shock garment: Historical relic or a device with unrealized potential?

Military anti-shock trousers represents a medical device which has engendered very divergent views, even up to today. From the time the concept was formulated in 1903 by surgeon George W Crile, there have been significant swings in opinion and evidence. The guidelines, where available, are often kept relatively general and cautious. As a spin-off to the mechanism and technology, several alternative devices have been proposed or developed over the years. This include the auto-transfusion torniquet, the non pneumatic anti-shock garment (Life Wrap) and the non inflatable antishock garment, which are discussed in this paper.

Surgical delays and outcomes in patients treated with pneumatic antishock garments: a population-based study

Until mid-1991, our emergency medical services (EMS) system required the routine application of pneumatic antishock garments (PASGs) in all trauma cases, and inflation of the garment if the patient was hypotensive (systolic blood pressure < 90 mm Hg). The findings in 398 trauma patients who underwent emergency surgery when PASG was still being routinely applied were compared with the findings in 590 trauma patients who underwent emergency surgery after routine PASG application had been discontinued. Since the discontinuation of routine PASG application, scene time intervals for "intermediate" blunt and penetrating trauma activations have not changed, but scene times for "full-activation" blunt trauma have actually increased (6.4 minutes with PASG and 9.5 minutes without PASG, P = .0004). Transport times were found to be a function of the type of trauma; patients with penetrating injuries were transported more rapidly (P < .0001) than patients with blunt trauma, even after controlling for injury severity and point of origin. Total time elapsed from EMS activation to the start of surgery for "full" activations, both blunt and penetrating, was unchanged (52.8 minutes with PASG and 53.8 minutes without PASG for penetrating trauma, 117.9 minutes with PASG and 105.1 minutes without PASG for blunt trauma). Times for "intermediate" activations did not change significantly. Length of intensive care unit (ICU) stay did not change. Within the subgroup of patients with femoral but not pelvic fractures, time spent at the scene of injury was shorter for patients treated with PASG than for those treated without (9.5 minutes v 14.5 minutes, P = .0066). Predicted and actual mortality rates were unchanged.(ABSTRACT TRUNCATED AT 250 WORDS)

The effect of heat load and dehydration on hypertonic saline solution treatment of uncontrolled hemorrhagic shock

Hypertonic saline solution treatment of uncontrolled hemorrhagic shock (UCHS) leads to increased bleeding from injured vessels, fall in arterial blood pressure, and increased mortality. The effect of dehydration induced by either water deprivation or heating on this response was studied in rats. The animals were divided into four groups: group 1 (n = 32), normal rats; group 2 (n = 30), water deprivation for 12 hours; group 3 (n = 30), heating at 37 degrees C for 5 hours; and group 4 (n = 30), heating as in group 3 and water deprivation as in group 2. UCHS was induced in all rats by 20% resection of the animals' tail. The rats were then divided into four treatment subgroups: group a was untreated, group b was treated after 15 minutes with 5 mL/kg NaCl 7.5% hypertonic saline (HTS), group c was treated after 15 minutes with 41.5 mL/kg NaCl 0.9% large volume normal saline (LNS) and group d was treated after 15 minutes with HTS + LNS. Tail resection in group 1a resulted in bleeding of 4.9 +/- 0.3 mL, and fall in mean arterial pressure (MAP) to 50 +/- 3 mm Hg (p < 0.001). Blood loss and fall in hematocrit in groups 2, 3, and 4 was significantly lower than in group 1. The fall in MAP and pulse rate was similar in all four groups.(ABSTRACT TRUNCATED AT 250 WORDS)