Fluid resuscitation in traumatic haemorrhage

Prolonged controlled hemorrhagic shock in a swine model: is there a role for mechanical circulatory assistance?

Outcomes of mechanical circulatory assistance during hemorrhagic shock were evaluated in a swine model. Pigs were bled to a mean arterial pressure of 35 mm Hg (group I, n = 3) or 40 mm Hg (group II, n = 5; group III, n = 5), maintained there for 30 minutes, and then resuscitated with fluids alone (groups I and II) or fluids plus mechanical circulatory assistance (group III). Mean blood loss was greater in group I than in groups II or III (1,037 +/- 212 vs. 862 +/- 387 ml vs. 681 +/- 117 ml, respectively; I vs. III, p < 0.05) and survival was shorter (230 +/- 25.5 min vs. 709 +/- 251 min vs. 662 +/- 428 min, respectively; I vs. II or III, p < 0.05). Cardiac arrhythmia caused death in most cases. Mean biochemical parameters increased progressively in all cases. Left anterior descending coronary artery flow stayed relatively constant in group II but increased in group III. Superior mesenteric artery flow returned to baseline in group II but increased in group III. Cardiac output was similar in groups II and III, but SGOT levels significantly differed (750 +/- 135 U/L vs. 359 +/- 157 U/L; p < 0.005). These results suggest that the swine model will be useful for studying ways to improve outcomes after prolonged hemorrhagic shock.

The efficacy and limitations of transarterial embolization for severe hepatic injury

BACKGROUND

The efficacy of transarterial embolization (TAE) for severe blunt hepatic injury has been reported. We performed a prospective study evaluating the efficacy and the limitation of TAE from January 1996 to December 2000.

METHODS

All patients with blunt abdominal injury who could be stabilized by fluid resuscitation underwent computed tomographic (CT) scan examinations. Patients with CT scan evidence of hepatic injury were classified into five grades according to CT scan findings on the basis of the injury scale of the American Association for the Surgery of Trauma (Mirvis classification). All patients with CT scan grade 3 to 5 injury underwent angiography. When angiography showed extravasation of contrast medium extending from hepatic arterial branches, TAE was performed.

RESULTS

Of 612 patients with blunt abdominal trauma, 51 had CT scan grade 3 to 5 injury. Thirty-seven of these patients had a CT scan grade 3 injury and 18 underwent TAE. One of 19 patients who did not undergo TAE developed a delayed hemorrhage on day 6 and required a laparotomy. All 13 patients with a CT scan grade 4 injury had angiographic findings of the extravasation. TAE was successful in 11 patients and unsuccessful in 2. Five patients with a CT scan grade 4 injury required laparotomy. One developed a delayed hemorrhage on day 4. The remaining four patients had a major venous injury (a right lobectomy was performed in two with inferior vena cava injury, and a gauze packing in two with hepatic venous injury). One patient with a CT scan grade 5 injury underwent immediate laparotomy after TAE. Laparotomy revealed inferior vena cava injury and a right lobectomy was performed. Only two patients who underwent a lobectomy died of an uncontrollable hemorrhage. All CT scans of patients with hepatic venous or inferior vena cava injury showed a large low-density area (> or = 10 cm) with involvement of these vessels. The volumes of fluid resuscitation needed from admission until TAE ranged from 2,109 to 2,638 mL/h.

CONCLUSION

It was considered that the combination of the presence of a CT scan grade 4 or 5 lesion and the fluid requirements of more than 2,000 mL/h to maintain normotension indicated the absolute necessity of surgery. We felt that these patients were not candidates for TAE, and should undergo immediate laparotomy.

The role of interventional radiology in the management of blunt renal injury: a practical protocol

OBJECTIVE

The purpose of this study was to evaluate the efficacy of a protocol designed to minimize the need for surgery in the management of severe blunt renal injury.

METHODS

Forty-six of 752 trauma patients had evidence of renal injury on computed tomographic (CT) scan. Two patients required emergency laparotomy, and the remaining 44 patients were classified by CT scan grade using the American Association for the Surgery of Trauma classification system. Patients with CT scan grade 3 or over underwent renal angiography.

RESULTS

Twenty-one patients had a high-grade injury on CT scan (> or =3). Eight had angiographic evidence of extravasation from renal arterial branches and underwent transarterial embolization. One patient with a grade 5 injury had extravasation from a main renal vein and underwent immediate laparotomy. This was the only patient who required surgery for renal injury.

CONCLUSION

Surgery can be avoided in most cases of blunt renal injury. Hemodynamic instability and injury to main renal veins remain indications for surgical exploration.

Blood loss estimation by out-of-hospital emergency care providers

OBJECTIVES

To evaluate emergency medical technicians' (EMTs') ability to estimate spilled blood volume and to determine whether limited training improves estimate accuracy and whether there is a difference in improvement comparing two different training methods.

METHODS

The study design was a single-blinded, clinical model, utilizing EMTs (basic, intermediate, and advanced) from a local commercial ambulance service. Participants estimated the volume of randomly selected volumes of packed red blood cells reconstituted to a normal hematocrit and poured onto three absorbent (carpet) and three nonabsorbent (vinyl) surfaces. Participants were then randomly assigned to one of two teaching groups. The SITEGRP (n = 17) returned to the six testing sites and were told the actual blood volumes. The SLIDE-GRP (n = 16) were taught with slides of six similar blood spill sites. Both groups were provided with suggestions for making volume estimates. The same participants were then retested one month later using the same type of sites and six new blood volumes.

RESULTS

Thirty-three participants with an average of 7.5 years of prehospital care experience completed testing on both dates. Mean percent error {[(estimated volume - actual volume)/actual volume] x 100} for all participants decreased from 65%+/-33% initially to 52%+/-20% after retesting (p < 0.05). Mean percent error was 74%+/-41% and 59%+/-20% for the SITEGRP (p < 0.15) initially and after retesting, respectively. Mean percent error was 56%+/-17% and 45%+/-17% for the SLIDEGRP (p < 0.05) initially and after retesting, respectively.

CONCLUSION

Prehospital care providers are not accurate at estimating spilled blood volumes. This ability can be improved with limited education. Slides appear to be as effective as viewing actual spill sites.