Pneumatic antishock garments (PASG): do they precipitate lower-extremity compartment syndromes?

Non-pneumatic anti-shock garment (NASG), a first-aid device to decrease maternal mortality from obstetric hemorrhage: a cluster randomized trial

Background

Obstetric hemorrhage is the leading cause of maternal mortality. Using a cluster randomized design, we investigated whether application of the Non-pneumatic Anti-Shock Garment (NASG) before transport to referral hospitals (RHs) from primary health care centers (PHCs) decreased adverse outcomes among women with hypovolemic shock. We hypothesized the NASG group would have a 50% reduction in adverse outcomes.

Methods and Findings

We randomly assigned 38 PHCs in Zambia and Zimbabwe to standard obstetric hemorrhage/shock protocols or the same protocols plus NASG prior to transport. All women received the NASG at the RH. The primary outcomes were maternal mortality; severe, end-organ failure maternal morbidity; and a composite mortality/morbidity outcome, which we labeled extreme adverse outcome (EAO). We also examined whether the NASG contributed to negative side effects and secondary outcomes. The sample size for statistical power was not reached; of a planned 2400 women, 880 were enrolled, 405 in the intervention group. The intervention was associated with a non-significant 46% reduced odds of mortality (OR 0.54, 95% CI 0.14–2.05, p = 0.37) and 54% reduction in composite EAO (OR 0.46, 95% CI 0.13–1.62, p = 0.22). Women with NASGs recovered from shock significantly faster (HR 1.25, 95% CI 1.02–1.52, p = 0.03). No differences were observed in secondary outcomes or negative effects. The main limitation was small sample size.

Conclusions

Despite a lack of statistical significance, the 54% reduced odds of EAO and the significantly faster shock recovery suggest there might be treatment benefits from earlier application of the NASG for women experiencing delays obtaining definitive treatment for hypovolemic shock. As there are no other tools for shock management outside of referral facilities, and no safety issues found, consideration of NASGs as a temporizing measure during delays may be warranted. A pragmatic study with rigorous evaluation is suggested for further research.

Trial Registration

ClinicalTrials.gov NCT00488462

Effectiveness and complications of pelvic circumferential compression devices in patients with unstable pelvic fractures: a systematic review of literature

BACKGROUND

Pelvic fractures can cause massive haemorrhage. Early stabilisation and compression of unstable fractures is thought to limit blood loss. Reposition of fracture parts and reduction of pelvic volume may provide haemorrhage control. Several non-invasive techniques for early stabilisation have been proposed, like the specifically designed pelvic circumferential compression devices (PCCD). The purpose of this systematic review was to investigate current evidence for the effectiveness and safety of non-invasive PCCDs.

METHODS

To investigate current literature the search string: "pelvi* AND fract* AND (bind* OR t-pod OR tpod OR wrap OR circumferential compression OR sling OR sheet)" was entered into EMBASE, PubMed (Medline), PiCarta, WebofScience, Cochrane Online, UptoDate, CINAHL, and Scopus. All scientific publications published in indexed journals were included.

RESULTS

The search resulted in 17 included articles, none of which were level I or II studies. One clinical cohort study (level III) and 1 case-control study (level IV) were found. These showed a significant reduction of pelvic volume after applying a PCCD, without an effect on outcome. Other included literature consisted of 4 case series (level V). Two biomechanical analysis studies of fractures in human cadavers showed pelvic stabilisation and effective volume reduction by PCCD, especially when applied around the greater trochanters. Finally, 7 case reports (level VI) and 3 expert opinions (level VII) were identified. These case reports suggested complications such as pressure sores and nerve palsy.

CONCLUSION

PCCDs seem to be effective in early stabilisation of unstable pelvic fractures. However, prospective data concerning mortality and complications is lacking. Some complications, like pressure sores have been described.

Hemorrhage in pelvic fracture: who needs angiography?

Pelvic fractures are rare but potentially devastating injuries. An understanding of the bony and peripelvic anatomy along with common patterns and the classification of the injury are of critical importance in their management. These form the basis for a general treatment algorithm for pelvic fracture patients. Angiographic embolization is time-consuming and often delayed. Hemodynamic instability with unstable pelvic fracture is therefore best approached with a combination of pelvic emergency stabilization (C-clamp) and surgical hemostasis by pelvic tamponade. This is especially true for critically injured patients in extremis.

Fluid and electrolyte deficit with prolonged pneumatic antishock garment application

OBJECTIVE

When trauma victims are within 1 hour of definitive surgical care, prehospital pneumatic antishock garment (PASG) application has not improved outcome. A resuscitative role for PASG has been suggested when transport time is longer (e.g., 4 hours). We assessed the fluid and electrolyte cost of treating posthemorrhagic hypotension with the PASG in 16 anesthetized Yorkshire piglets (30 to 32 kg).

DESIGN

Hypotension [30 mm Hg drop in carotid arterial blood pressure (CBP)] was produced by arterial line bleeding. Hemodynamics, serum electrolytes, lactate, and tissue edema (limb circumference) were monitored.

MATERIALS AND METHODS

In eight animals (group 1), PASG was inflated to maintain prebleed CBP for 4 hours. In group 2, the hypotension was untreated for 4 hours. After 4 hours, shed blood (over a period of 15 minutes) and normal saline (1.5 mL/kg/minute) were infused until CBP returned to normal baseline values.

MEASUREMENTS AND MAIN RESULTS

Shed blood alone did not restore baseline CBP. Serum K+ increased from a baseline of 3.9 to 9.1 mmol/L in group 1, with no significant change in group 2. Serum lactate rose from 1.8 to 24.1 and from 1.7 to 6.8 mmol/L in groups 1 and 2, respectively. After 4 1/2 hours, an increase in thigh circumference (6.4 +/- 1.4 vs. 1.9 +/- 1.0 mm) and intravenous fluid required after returning shed blood (626 +/- 36 vs. 324 +/- 22 mL) was greater in group 1 (means +/- SD, p < 0.05). Other serum electrolyte values were similar for the two groups.

CONCLUSIONS

We conclude that fluid deficit, lactic acidosis, tissue edema, and hyperkalemia are all greater with prolonged PASG application when compared with the untreated hypotensive state. These findings must be considered when suggesting more prolonged PASG application.

Pneumatic antishock garment-associated compartment syndrome in uninjured lower extremities

Pneumatic antishock garment-associated compartment syndrome is a rare and yet underrecognized complication that when it occurs, frequently results in myonecrosis and loss of limb function, and occasionally loss of a limb or even death. We report a case of pneumatic antishock garment-associated compartment syndrome in a trauma patient without lower extremity injury and review similar published reports. It is only with a high index of suspicion, early recognition, and prompt treatment of this complication by fasciotomy and proper wound care that associated morbidity and potential mortality of this complication can be prevented or minimized.

Compartment syndrome: a complication of acute extremity trauma

Compartment syndrome is a serious potential complication of trauma to the extremities. Fractures, crush injuries, burns, and arterial injuries, among others, can result in increased tissue pressure within closed osseofascial or compartmental spaces. Prolonged exposure to elevated pressure can result in nerve and muscle necrosis. Extreme pain unrelieved with analgesia, subjective complaint of pressure, pain with passive muscle stretching, paresis, paresthesia, and intact pulses, in the presence of a physically tight compartment, should alert the physician to the presence of a compartment syndrome. The diagnosis is a clinical one, but it may be aided by measurements of intracompartmental tissue pressures. Compartment syndrome is a surgical emergency requiring prompt treatment by fasciotomy. Time is a critical factor; the longer the duration of elevated tissue pressure, the greater the potential for disastrous sequelae. Emergency medicine providers must be cognizant of this clinical syndrome so that early emergent surgical consultation can be obtained to avoid complications.

[Antishock trousers in the prevention of air embolism]

This study aimed to assess the efficiency and safety of military anti-shock trousers (MAST) in preventing venous air embolism in children undergoing neurosurgical procedures in the sitting position. It included 26 children, 7.7 +/- 4-year-old and weighing 25.4 +/- 10.5 kg. All had the same anaesthetic protocol including premedication with oral lorazepam, induction with thiopentone or propofol with fentanyl and vecuronium, and maintenance with isoflurane and a continuous infusion of fentanyl. In 10 patients, a retrograde central venous catheter was inserted for measurement of pressure in the superior bulb of the internal jugular vein. Haemodynamic measurements were carried out with the patient supine; with the patient sitting, the MAST not being inflated; 10 min after inflation of the MAST (40 mmHg in the limbs, 30 mmHg in the abdominal part); after starting 10 cmH2 O positive end expiratory pressure; and after fluid administration with 5 ml.kg-1 macromolecules (Plasmion). The criterion for air embolism was a decrease in PetCO2 of more than 5 mmHg over more than 30 s, not preceded by respiratory or cardiovascular impairment. Inflation of the MAST resulted in a dramatic rise in venous pressure, still reinforced by minor PEEP. Transmission of pressure from the right atrium to the dural sinus was linear, and seemed to be sufficient to prevent occurrence of detectable venous air emboli. No deleterious side-effects were noted. This method would therefore seem to be very efficient, preserving the advantages of the sitting position, and restricting its disadvantages. Unfortunately, the limited availability of different paediatric sizes of MAST reduces the possible uses of this method.

Fasciotomy after trauma to the extremities

Over a 9-year period, fasciotomy for presumed compartmental syndromes after trauma was performed in 25 upper extremities and 100 lower extremities in 122 patients. This procedure was most commonly indicated after vascular injuries in the lower extremities. Twenty percent of patients underwent fasciotomy before vascular repair. Nineteen percent of patients with vascular injuries in the lower extremities had fasciotomies performed at reoperation. Seventy-five percent of amputations in the lower extremities were related to a delay in performing fasciotomy or an incomplete fasciotomy. Upper-extremity fasciotomies most commonly did not decompress the deep component of the volar compartment, whereas lower extremity fasciotomies without fibulectomy most commonly decompressed all four below-knee compartments. Fasciotomy sites were closed by direct suture in more than half of the patients.