Pneumatic anti-shock garment: state of the art 1988

Obstetric hemorrhage in resource-limited locations: A quality improvement project after adoption of abdominopelvic compression devices

OBJECTIVE

To evaluate obstetric hemorrhage outcomes and present data specific to adoption of pneumatic circumferential abdominopelvic compression devices.

METHODS

Two resource-limited locations added low-cost pneumatic compression devices to their standard protocols for obstetric hemorrhage between 2010 and 2019. Providers in rural Nepal and Papua New Guinea used devices that incorporated a bicycle tube or soccer ball ("Ball and Binder") to provide abdominopelvic pressure after all available routine treatments had failed. Data were collected during the entire period as part of ongoing obstetric quality improvement. Data presented include obstetric event, etiology of bleeding, need for surgery, transfusion, transport, length of transports, maternal survival, and complications.

RESULTS

Circumferential abdominopelvic compression was used 106 times. The devices were used primarily after vaginal birth with atony, but also for obstetrical lacerations, miscarriages, and post-abortion bleeding. In all cases the bleeding stopped "promptly." All women survived, none required hysterectomy, and no complications were reported resulting from device use. Only 15 (14%) patients were transported to a referral hospital.

CONCLUSION

In this quality improvement project, obstetric hemorrhage was controlled when circumferential pressure was applied after usual care had failed.

History and significance of the trauma resuscitation flow sheet

There is little to no written information in the literature regarding the origin of the trauma flow sheet. This vital document allows programs to evaluate initial processes of trauma care. This information populates the trauma registry and is reviewed in nearly every Trauma Process Improvement and Patient Safety conference when discerning the course of patient care. It is so vital, a scribe is assigned to complete this documentation task for all trauma resuscitations, and there are continual process improvement efforts in trauma centers across the nation to ensure complete and accurate data collection. Indeed, it is the single most important document reviewed by the verification committee when evaluating processes of care at site visits. Trauma surgeons often overlook its importance during resuscitation, as recording remains the domain of the trauma scribe. Yet it is the first document scrutinized when the outcome is less than what is expected. The development of the flow sheet is not a result of any consensus statement, expert work group, or mandate, but a result of organic evolution due to the need for relevant and better data. The purpose of this review is to outline the origin, importance, and critical utility of the trauma flow sheet.

The Compartment Syndrome of the Abdominal Cavity: A State of the Art Review

Abdominal compartment syndrome gains increasing recognition. It impairs physiology and requires treatment. It occurs more commonly with acute rather than chronic abdominal hypertension. Functional impairments involve the cardiovascular system, respiratory system, hepatic, renal, and gastrointestinal function, and intracranial pressure. Abdominal hypertension decreases venous return, increases systemic vascular resistance and intrathoracic pressure, and therefore reduces cardiac output. It also adversely affects cardiovascular monitoring. In the presence of increased abdominal pressure, atelectasis and pneumonia are likely to develop and impaired ventilation may lead to respiratory failure. Also, blood flow to the liver and kidney may be reduced, resulting in functional impairment of both organs. The adverse effects on gastrointestinal function result from impairing lymphatic, venous, and arterial flow. Anastomotic healing may become a problem under these circumstances. Decreased venous return through the inferior vena cava in obese patients may lead to venous stasis ulcers and hemorrhage. The correlation of increased intracranial pressure and intra-abdominal pressure may be a problem for trauma patients with simultaneous injuries to the head and the abdomen. There are three severity grades of increased intra-abdominal pressure: Acute sustained elevation of intra-abdominal pressure above 10–20 mmHg is called mild abdominal hypertension. Physiologic effects are generally well compensated and usually clinically nonsignificant. Nonoperative therapy may be required. Moderate hypertension is defined as sustained elevation of 21–35 mmHg. Therapy is generally necessary. Surgical abdominal-decompression may be critical. Severe hypertension or abdominal compartment syndrome is defined as sustained elevation above 35 mmHg. Operative decompression is always indicated. The gap between the abdominal wound edges must be temporarily covered to prevent fascia retraction and formation of a huge hernia. All detrimental effects of elevated intra-abdominal pressure and the methods and benefits of its decompression have been well studied, both in the laboratory and in clinical practice. Diagnostic suspicion may be confirmed with objective measurements of intra-abdominal pressure to select patients who may benefit from decompression. Operative decompression is achieved by abdominal fasciotomy and covering the fascial gap with mesh made of Marlex®, Gore-Tex®, silastic, or by a Velcro-like closure mesh (artificial bur). All meshes help to effectively decompress the abdomen. The artificial bur offers further advantages by permitting successive reapproximation of the fascia until final fascial closure, and avoiding the fistula and hernia formation seen with the other meshes.

An inexpensive device to treat postpartum hemorrhage: a preliminary proof of concept study of health provider opinion and training in Nepal

Background

Obstetric hemorrhage remains the leading cause of maternal mortality in resource limited areas. An inexpensive pneumatic anti-shock garment was devised of bicycle tubes and tailored cloth which can be prepared from local materials in resource-limited settings. The main purposes of this study were: 1) to determine acceptability of the device by nurses and midwives and obtain suggestions for making the device more suitable for use in their particular work environments, 2) to determine whether a three hour training course provided adequate instruction in the use of this device for the application of circumferential abdominal pelvic pressure, and 3) determine production capability and cost in a resource-limited country.

Methods

Fifty-eight nurse and midwife participants took part in three sessions over eight months in Nepal. Correct device placement was assessed on non-pregnant participants using ultrasound measurement of distal aortic flow before and after device inflation, and analyzed using confidence intervals. Participants were surveyed to determine acceptability of the device, obtain suggestions for improvement, and to collect data on clinical use.

Results

Device placement achieved flow decreases with a mean of 39% (95% CI 25%-53%, p < 0.001) in the first session, 28% (95% CI 21%-33%, P < 0.001) after four months and 29% (95% CI 24%-34%, p < 0.001) at 8 months. All nurses and midwives thought the device would be acceptable for use in obstetric hemorrhage and that they could make, clean, and apply it. They quickly learned to apply the device, remembered how to apply it, and were willing and able to use the device clinically. Ten providers used the device, each on one patient, to treat obstetric hemorrhage after routine measures had failed; bleeding stopped promptly in all ten, two of whom were transported to the hospital. Production of devices in Kathmandu using local tailors and supplies cost approximately $40 per device, in a limited production setting.

Conclusions

Preliminary data suggest that an inexpensive, easily-made device is potentially an appropriate addition to current obstetric hemorrhage treatment in resource-limited areas and that further study is warranted.

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

Medical Anti-Shock Trousers: Pneumatic Anti-Shock Garment: Does it Work?

The use of the Pneumatic Anti-Shock Garment (PASG) has created much controversy in prehospital care. It is interesting that such an inexpensive device and technique has created so much controversy regarding effectiveness when expensive devices and techniques, such as coronary artery bypass, carotid endarteroectomy, and laser angioplasty have been questioned as to effectiveness, but have not created as much controversy.

Where do we stand on the PASG today? One well-done, randomized, prospective study has been reported as several different papers. In reality, these reports originate from only one study (1-5). This is compared to more than 200 other studies, many of which have been randomized, prospective studies in animals using the same quality as the randomized, prospective study done on humans. Such studies have the advantage of having better isolation of the specific condition being studied. It does not seem appropriate to base the clinical use or non-use on just one study. All studies should be reviewed and placed in context when attempting to identify the role the PASG has in patient care.

Medical Anti-Shock Trousers: Blind Faith, Poor Judgment and Patient Jeopardy

The oft-repeated historic development of the pneumatic lower body compression suit (MAST, PASG) for the presumed treatment of hypotension has been well-documented by McSwain(l). While the experimental and anecdotal clinical observations of Crile, Gardner, Wangenstein and Kaplan are interesting, they are not prospective, controlled, randomized clinical trials in humans(2,3,4,5). In the early 1970s, the EMS community was ripe for the bandwagon reflex to grasp at any and all gimmicks and gadgets which became available, regardless of a lack of evidence regarding their safety or danger to patients. Inventions such as the esophageal obturator airway, various darts, MAST, external cardiac bumpers, percutaneous trachea obturators, and many others simultaneously were thrust upon the unsuspecting and unprotected patient community. Some of these innovations may have been beneficial but others were dangerous. Contending that some intervention in a “life threatening, good Samaritan situation” was better than no interventional treatment or “stabilization” at all, the paramedics' blind faith in these modalities persisted. The Medical Device Amendment of 1976 (6), which requires safety and efficacy for devices, similar to that long in effect for new drugs, had not yet been enacted into law to require premarketing clearance of new medical devices. Building on blind faith and premature recommendations regarding in the unproven concept of MAST, the EMS community exercised poor judgment in recommending to state legislators that this unproven device be “required equipment” on board ambulances. Furthermore, this small cadre of “special interest groups” lobbied to have the MAST mandated as essential equipment in trauma centers(7,8). Although the minutes of the trauma planning meetings do not reflect the debate at the American College of Surgeons Committee on Trauma, numerous voices of advised constraint, said “go slow” on including the MAST as part of the ATLS course and the ACS optimal resources document.

Impact of the Non-pneumatic Antishock Garment on pelvic blood flow in healthy postpartum women

OBJECTIVE

The Non-pneumatic Antishock Garment (NASG) is a compression device that has shown significantly decreased blood loss in cases of obstetric hemorrhage. However, there are no physiologic studies of the NASG in postpartum women. This study used Doppler ultrasound to measure the resistive index (RI) in the internal iliac artery, thus approximating blood flow to the pelvis with and without the garment applied.

STUDY DESIGN

In this study, RI of the internal iliac artery was measured in a sample of 10 postpartum volunteers with and without the NASG applied. Median RI was calculated and compared between baseline and full application.

RESULTS

Internal iliac artery median RI was 0.83 (SD 0.11) at baseline and increased to 1.05 (SD 0.15) with full NASG application (P = .02).

CONCLUSION

This study suggests a significant increase in internal iliac artery RI with NASG application and provides a physiological explanation of how the NASG might reduce postpartum hemorrhage.

CEU: Prevention and Treatment of Postpartum Hemorrhage: New Advances for Low-Resource Settings

Postpartum hemorrhage due to uterine atony is the primary direct cause of maternal mortality globally. Management strategies in developed countries involve crystalloid fluid replacement, blood transfusions, and surgery. These definitive therapies are often not accessible in developing countries. Long transports from home or primary health care facilities, a dearth of skilled providers, and lack of intravenous fluids and/or a safe blood supply often create long delays in instituting appropriate treatment. We review the evidence for active management of third-stage labor and for the use of specific uterotonics. New strategies to prevent and manage postpartum hemorrhage in developing countries, such as community-based use of misoprostol, oxytocin in the Uniject delivery system, the non-inflatable antishock garment to stabilize and resuscitate hypovolemic shock, and the balloon condom catheter to treat intractable uterine bleeding are reviewed. New directions for clinical and operations research are suggested.

A thermodynamic model to predict the thermal response of living beings during pneumoperitoneum procedures

In this work, hypothermia associated with pneumoperitoneum procedures is studied. A thermodynamic model is developed to allow for the computational simulation of the thermal body response to pneumoperitoneum procedures, which are required by laparoscopic surgery. The numerical results predict the body temperature decay (or loss of energy) in time when the pneumoperitoneum procedures is conducted in patient. The influence of several operating parameters (e.g. inlet air mass flow rate and temperature) on the resulting hypothermia level is analysed. Therefore, the model allows the identification of parameters that have to be controlled to minimize the loss of energy, and consequently, the hypothermia level due to pneumoperitoneum procedures.

Use of the non-pneumatic anti-shock garment (NASG) to reduce blood loss and time to recovery from shock for women with obstetric haemorrhage in Egypt

Obstetric haemorrhage is one of the leading causes of maternal mortality. In many low-resource settings, delays in transport to referral facilities and in obtaining lifesaving treatment, contribute to maternal deaths. The non-pneumatic anti-shock garment (NASG) is a low-technology pressure device that decreases blood loss, restores vital signs, and has the potential to improve adverse outcomes by helping women survive delays in receiving adequate emergency obstetric care. With brief training, even individuals without medical backgrounds can apply this first-aid device. In this secondary analysis of hospital data from a pre-post intervention study in Egypt (N=364 women with obstetric haemorrhage and shock), 158 received standard care, while 206 received standard care plus the NASG. The NASG significantly reduced blood loss, time to recovery from shock, and, for those with postpartum haemorrhage due to uterine atony who received oxytocin, the NASG had a significant effect on blood loss independent of oxytocin. These results indicate that the NASG may be a valuable innovation for reducing maternal mortality in low-resource settings. Testing at community and household levels will be necessary in order to determine whether the NASG can help women survive the longest delays.

Anti-shock garment in postpartum haemorrhage

The non-pneumatic anti-shock garment (NASG) is a first-aid device that reverses hypovolaemic shock and decreases obstetric haemorrhage. It consists of articulated neoprene segments that close tightly with Velcro, shunting blood from the lower body to the core organs, elevating blood pressure and increasing preload and cardiac output. This chapter describes the controversial history of the predecessors of NASG, pneumatic anti-shock garments (PASGs), relates case studies of PASG for obstetric haemorrhage, compares pneumatic and non-pneumatic devices and posits why the NASG is more appropriate for low-resource settings. This chapter discusses the only evidence available about NASGs for obstetric haemorrhage - two pre-post pilot trials and three case series - and describes recently initiated randomized cluster trials in Africa. Instructions and an algorithm for ASGs in haemorrhage and shock management are included. Much remains unknown about the NASG, a promising intervention for obstetric haemorrhage management.

Postoperative gastric dilatation causing abdominal compartment syndrome

OBJECTIVE

To study the effect of postoperative gastric dilatation on intra-abdominal pressure (IAP).

DESIGN AND SETTING

Single case report from a primary teaching hospital.

PATIENTS AND METHODS

A 72-year-old woman demonstrated a sudden respiratory and cardiovascular collapse following resection of a retroperitoneal sarcoma. This collapse was caused by abdominal compartment syndrome due to gastric dilatation.

RESULTS

The patient was re-explored, an enormously distended stomach was found with the nasogastric tube situated in a small sliding hernia which prevented drainage of the distended stomach. Re-positioning of the nasogastric tube, allowed the decompression of the stomach and the patient's condition immediately improved.

CONCLUSION

Acute abdominal distention following major abdominal surgery may result from acute gastric dilatation, leading to oliguria and increased airway pressures. Untreated gastric dilatation can cause abdominal compartment syndrome.

First aid for obstetric haemorrhage: the pilot study of the non-pneumatic anti-shock garment in Egypt

OBJECTIVE

To compare the effect of non-pneumatic anti-shock garment (NASG) on blood loss from obstetric haemorrhage with standard management of obstetric haemorrhage.

DESIGN

Observational study of consecutive obstetric haemorrhage cases before and after introduction of the NASG.

SETTING

Four tertiary care maternity facilities in Egypt.

SAMPLE

The sample consisted of women with obstetric haemorrhage and signs of shock and the entry criteria were: >750 mL of blood loss and either pulse of >100 beats per minute or systolic blood pressure of <100 mmHg. A total of 158 women were in the preintervention group and 206 in the postintervention group.

METHODS

All the women with haemorrhage meeting the eligibility criteria were treated according to the standard protocol for 4 months (May-August 2004); blood loss was measured and recorded. The NASG was then introduced, and all the women meeting the eligibility criteria were treated according to the standard haemorrhage protocol plus the NASG for 4 months (September-December 2004).

MAIN OUTCOME MEASURES

Measured blood loss collected in a closed-end, graduated, plastic, under buttocks collection drape.

RESULTS

Median measured blood loss in the drape following study entry was 50% lower in those treated with the NASG (250 versus 500 mL, P < 0.001). There was also a non-statistically significant decrease in morbidity and mortality.

CONCLUSIONS

This is the first comparative study of the NASG with a standard obstetric haemorrhage treatment protocol. The NASG shows promise for management of obstetric haemorrhage, particularly in lower resource settings. Larger studies will be needed to determine if the NASG contributes to statistically significant decreases in morbidity and mortality.

Opinions of Trauma Practitioners Regarding Prehospital Interventions for Critically Injured Patients

BACKGROUND

Significant controversy surrounds the prehospital management of trauma patients.

METHODS

A questionnaire describing clinical scenarios was mailed to a random sample of 345 trauma practitioners.

RESULTS

The 182 trauma practitioners (52.8%) who returned the surveys were predominantly general or trauma surgeons (83.5%) in academic or university practice (68.1%). For a patient with a severe traumatic brain injury, 84.5% of trauma practitioners recommended that emergency medical services personnel attempt intubation at least once when transport time was 20 to 40 minutes. For a patient with a gunshot wound to the epigastrium in decompensated shock, the majority of trauma practitioners believed that a relatively hypotensive state should be maintained, regardless of transport time. Trauma practitioners (52.2%) have recommended the use of the pneumatic antishock garment for transports of 20 to 40 minutes for patients with an unstable pelvic fracture and decompensated shock.

CONCLUSIONS

Most trauma practitioners believe that emergency medical services providers should attempt intubation for a patient with a severe traumatic brain injury, should treat decompensated shock in a patient with penetrating torso trauma but maintain the patient in a relatively hypotensive state, and should apply and inflate the pneumatic antishock garment for a suspected pelvic fracture accompanied by decompensated shock if the patient is 20 to 40 minutes from a trauma center. The recommendations of trauma practitioners regarding appropriate prehospital care are significantly influenced by the time required for transport to the trauma center.

A non-inflatable anti-shock garment for obstetric hemorrhage

OBJECTIVES

Maternal death from hemorrhage in low resource settings is frequently due to long delays in transportation to referral centers and/or in obtaining blood and surgical interventions. This case series was designed to demonstrate the feasibility, efficacy and safety of the non-inflatable anti-shock garment (NI-ASG) for resuscitation and hemostasis in the initial management of obstetric hemorrhage and shock.

METHODS

Fourteen cases of obstetric hemorrhage and hypovolemic shock at Memorial Christian Hospital, Sialkot, Pakistan were managed with a specific clinical protocol based on using NI-ASG as the primary intervention.

RESULTS

The NI-ASG was used to resuscitate and stabilize women with hypovolemic shock from 18 to 57 h. Thirteen patients survived without evidence of morbidity, but one had prolonged shock followed by multiple organ failure and death.

CONCLUSIONS

This study confirmed that the NI-ASG quickly restored the vital signs of most women in severe hemorrhagic shock and stabilized them while awaiting blood transfusion.

Regional blood flow after pneumatic anti-shock garment inflation

OBJECTIVE

To determine whether fully inflated pneumatic anti-shock garments (PASGs) decrease blood flow to abdominal and retroperitoneal organs.

METHODS

An experimental study was conducted using a convenience sample of ten healthy adults. A duplex Doppler ultrasound was used to image and measure blood flow at the aortic root (cardiac output), left carotid artery, left subclavian artery, superior mesenteric artery (SMA), left renal artery, and distal aorta. Each subject was imaged before and after inflation of all three compartments of the garment to 90 mm Hg. Data were analyzed with paired t-tests.

RESULTS

PASG inflation did not affect cardiac output (5.45 vs. 5.83 L/min, 95% confidence limit (CL) for mean -0.97 to 0.30, p = 0.26), left carotid artery flow (0.34 vs. 0.35 L/min, 95% CL for mean -0.06 to 0.04, p = 0.70), or left subclavian artery flow (0.12 vs. 0.11 L/min, 95% CL for mean -0.01 to 0.03, p = 0.47). Inflation did cause the aortic flow immediately distal to the renal artery to decrease markedly in all subjects (1.01 vs. 0.11 L/min, 95% CL for mean 0.79 to 1.19, p < 0.001). Flow immediately above this point appeared unaffected. Physical interference with the ultrasound probe by the garment precluded measurement of SMA or renal artery flow in five subjects. In the remaining subjects, these values did not change significantly (SMA 0.40 vs. 0.28 L/min, 95% CL for mean -0.11 to 0.33, p = 0.23; renal artery 0.44 vs. 0.51 L/min, 95% CL for mean -0.09 to 0.08, p = 0.78).

CONCLUSION

PASG inflation caused a dramatic decrease in aortic blood flow over a small area immediately distal to the renal arteries but had little or no effect above this point. This provides support for the use of PASG to decrease otherwise uncontrollable hemorrhage from the iliac, pelvic, and leg vessels, but not for injuries above them.

Planning for hemorrhage. Steps an anesthesiologist can take to limit and treat hemorrhage in the obstetric patient

Obstetric hemorrhage continues to be a significant cause of maternal mortality and morbidity. Blood transfusion in such circumstances may be life saving but involves exposing the patient to additional risks. Limiting blood transfusion and using autologous blood when possible may reduce some of these risks. This article outlines the techniques that may be used to limit and more effectively treat hemorrhage in the obstetric patient, with particular attention paid to reducing the use of allogeneic blood transfusion.

The abdominal compartment syndrome following aortic surgery

BACKGROUND

multi-organ failure is a leading cause of death following aneurysm surgery, especially in the emergency setting. Intra-abdominal hypertension is an important factor in the development of multi-organ failure. Prevention, early recognition and prompt treatment of abdominal hypertension and the abdominal compartment syndrome may reduce mortality following aneurysm surgery.

METHODS

a descriptive review of the literature from a Medline search.

RESULTS AND CONCLUSIONS

the abdominal compartment syndrome is the result of diverse physiological effects caused by increased intra-abdominal pressure. The syndrome has been most widely described in trauma victims, but occurs in patients following aortic surgery, particularly following ruptured aneurysm repair. Preventative therapy should be instituted to minimise its development in patients at risk, and monitoring of intra-abdominal pressure may allow prompt treatment of this condition.

Anti-shock garment provides resuscitation and haemostasis for obstetric haemorrhage

OBJECTIVE

To evaluate the feasibility, safety and effectiveness of the non-pneumatic anti-shock garment for resuscitation and haemostasis following obstetric haemorrhage resulting in severe shock.

DESIGN

During a six-week period, the author served a locum tenens as the obstetrician consultant for the Memorial Christian Hospital, Sialkot, Pakistan. All women who suffered from severe obstetric haemorrhage were managed with the anti-shock garment as the first intervention. The data for this report were collected from hospital chart review.

SETTING

Sialkot is a city of about three million and Memorial Christian Hospital is one of two major obstetric hospitals. There is no blood bank at Memorial Christian Hospital or elsewhere in Sialkot. The Memorial Christian Hospital laboratory is able to draw donor blood, type and cross match blood, and process it for transfusion 24 hours per day.

POPULATION

During the six weeks of this study, in June and July 2001, there were 764 deliveries and 34 other admissions within a week following deliveries outside the hospital. Seven women with obstetric haemorrhage who developed severe shock were managed with the anti-shock garment. One woman, who was later found to have mitral stenosis, developed dyspnea upon placement of the anti-shock garment and therefore it was removed within 5 minutes. This report concerns the six women who were able to tolerate the anti-shock garment without untoward symptoms.

METHODS

As soon as severe shock was recognised in the hospital, the anti-shock garment was placed. Crystalloid solutions were given intravenously over the first hour at a rate of 1500 mL per estimated litre of blood loss, then at a maintenance rate of 150 mL/hour. Vital signs every 15 to 30 minutes, hourly urine output and intermittent oxygen saturation were used to monitor patients during the use of the anti-shock garment. When sufficient blood transfusion had been given to restore the haemoglobin to >7 g/dL, the anti-shock garment was removed in segments at 15-minute intervals with documentation of vital signs before removal of each subsequent portion.

MAIN OUTCOME MEASURES

Restoration of mean arterial pressure of 70 mmHg and clearing of sensorium were considered as signs of effective resuscitation. Haemorrhage was considered controlled if the blood loss was less than 25 mL/hour. Morbidity included any complications noted in the medical chart.

RESULTS

Restoration of blood pressure and improvement of mental status occurred within 5 minutes in two patients who were pulseless and three who were unconscious or confused. All patients had improvement of mean arterial pressure to greater than 70 mmHg within 5 minutes. Duration of anti-shock garment use ranged from 12 to 36 hours and none of the six women had significant further bleeding while the anti-shock garment was in place. Patients were comfortable during use of the anti-shock garment and no adverse effects were noted apart from a transient decrease in urine output.

CONCLUSIONS

The anti-shock garment rapidly restored vital signs in women with severe obstetric shock. There was no further haemorrhage during or after anti-shock garment use and the women experienced no subsequent morbidity. A prospective randomised study of the anti-shock garment for management of obstetric haemorrhage is needed to further document these observations.

Advanced or basic life support for trauma: meta-analysis and critical review of the literature

BACKGROUND

The question of whether to use advanced life support (ALS) or basic life support (BLS) for trauma patients in the prehospital setting has been much debated and still lacks a clear answer. The purpose of this study was to conduct a comprehensive critical review of the literature regarding this controversy

METHODS

A total of 174 articles on prehospital ALS or BLS for trauma were reviewed. Fifteen of these studies were found to involve mortality statistics for both ALS- and BLS-treated patients. Odds ratios were calculated for survival in ALS versus BLS and summarized across studies on the basis of multivariate scoring systems that incorporated both design and methodological assessment. Overall odds ratios for all studies were calculated on the basis of both raw data from the papers, and weighted odds ratios were calculated from the scoring systems.

RESULTS

Six studies were scored as being methodologically average (5 favoring BLS and 1 favoring ALS), two were scored as good (1 favoring BLS and 1 favoring ALS), seven as excellent (6 favoring BLS and 1 favoring ALS). Ten studies had an average study design score (6 favoring BLS and 4 favoring ALS) and seven had a good study design score (6 favoring BLS and 1 favoring ALS). Weighted odds ratio for dying was 2.59 for patients receiving ALS compared with those receiving BLS. The crude odds ratio was 2.92.

CONCLUSION

The aggregated data in the literature have failed to demonstrate a benefit for on-site ALS provided to trauma patients and support the scoop and run approach.

Abdominal haemorrhage--a preventable cause of death after field stabilization?

The causes of preventable death vary in different operational settings, and the topic has not previously been explored in a fully developed central European rescue system. The factors associated with potentially preventable death were studied in a retrospective study of 430 fatal traffic accident victims (1980-96) in Lörrach County, Germany. Mission protocols could be retrieved for detailed analysis in 239 of the cases. These were studied in order to identify factors associated with preventable death. At the scene of the accident, 38% of the patients died without cardiopulmonary resuscitation (CPR) and 18% after CPR. Four patients died after a certain delay without CPR before reaching hospital. A total of 43% of the victims were admitted to hospital, 5% had received prehospital CPR and the remaining 38% had not. In a subgroup representing the experience of a single emergency physician 60 fatalities were studied. Of these, 27 (45%) patients died within the hospital; almost half of these cases (13/27) had been conscious at some time after the accident and of these, seven (7/13) died from intra-abdominal bleeding within 4 h after admission. The same cause of death was found in 3 of the 14 comatose patients. Pleural drainage was carried out in four patients and unrecognized pneumothoraces or spinal injuries did not occur. Tracheal intubation was employed in 24/27. Medical antishock trousers (MAST) were not available. The data indicate that intra-abdominal haemorrhage is an underestimated cause of death in a comprehensive rescue system, possibly as a consequence of field stabilization. The use of MAST may be a relevant therapeutic option to prevent these fatalities. The method offers the possibility of intra-abdominal compression and haemostasis after tracheal intubation has been performed. Previous controlled studies on MAST may have been biased by faulty methodology (e.g. absence of tracheal intubation) and inappropriate indications (e.g. other causes of shock). The value of MAST in comprehensive rescue systems should therefore be reassessed. The difficulties in identifying factors leading to preventable death in a retrospective analysis, are discussed and it is recommended that a permanent prospective quality control be performed in all cases of fatal accidents in order to ensure the continued improvement of prehospital emergency medical systems.

Pneumatic antisnock garment: state of the art at the turn of the century

The pneumatic antishock garment (PASG) accomplishes in 1999 exactly what Crile postulated that it did in 1901. It increases blood pressure by increasing systemic vascular resistance. No published article counters this fact. The weakness that has become apparent is that this increase in blood pressure can also increase haemorrhage and therefore does not necessarily improve outcome in every patient. Patients in profound shock benefit from the reduction in the vascular space and increased systemic vascular resistance, without excessive additional blood loss. Patients without ongoing haemorrhage benefit from increased blood pressure. Patients with ongoing haemorrhage in the abdomen, retroperitoneal area and pelvis benefit as the rate of blood loss is reduced. The controversy that has been sparked by the device is `what is the end point for resuscitation?'. Two randomized studies using the same method for PASG application and large volume replacement of intravenous (iv) fluids has produced the same outcome. One study has been readily accepted while the other has not. If the PASG is bad for resuscitation then so is large volume iv fluid replacement. One cannot accept scientifically or logically one study without accepting the other. The current indications for PASG are haemorrhage control in the abdomen, retroperitoneum and pelvis, and short-term management of profound shock.

Abdominal compartment syndrome

The ACS is a clinical entity that develops from progressive, acute increases in IAP and affects multiple organ systems in a graded fashion because of differential susceptibilities. The gut is the organ most sensitive to IAH, and it develops evidence of end-organ damage before the development of the classic renal, pulmonary, and cardiovascular signs. Intracranial derangements with ACS are now well described. Treatment involves expedient decompression of the abdomen, without which the syndrome of end-organ damage and reduced oxygen delivery may lead to the development of multiple organ failure and, ultimately, death. Multiple trauma, massive hemorrhage, or protracted operation with massive volume resuscitation are the situations in which the ACS is most frequently encountered. Knowledge of the ACS, however, is also essential for the management of critically ill pediatric patients (especially those with AWD) and in understanding the limitations of laparoscopy. The role of IAH in the pathogenesis of NEC, central obesity co-morbidities, and pre-eclampsia/eclampsia remains to be fully studied.

Hemodynamic, renal, and hormonal responses to lower body positive pressure in human subjects

Studies in healthy human subjects subjected to lower body positive pressure (LBPP) have failed to elucidate many of the physiologic effects of this maneuver. In 7 healthy, well-hydrated men we studied the following responses to LBPP (35 mm Hg, 1 hour, supine position): systemic and renal hemodynamics; urine volume (UV), urine osmolality (Uosm), and urine sodium level (UNaV); free water (CH20) and osmolar (Cosm) clearances; plasma renin activity (PRA); levels of aldosterone (PA), cortisol (CORT), norepinephrine (NE), atrial natriuretic peptide (ANP), and vasopressin (AVP); osmolality (Posm); and serum sodium level. Subjects were restudied on a control day with zero trouser pressure. The recorded changes (p < 0.05) when comparing the LBPP day with the control day were as follows: fractional Na+ reabsorption increased (98.7% +/- 0.2% to 99.3% +/- 0.1%) and UNaV decreased (0.19 +/- 0.03 mEq/min to 0.10 +/- 0.01 mEq/min), with concomitant increases in PRA (1.7 +/- 0.2 ng/ml/90 min to 4.5 +/- 1.8 ng/ml/90 min), PA (7.7 +/- 0.7 ng/dl to 9.3 +/- 1.5 ng/dl), and CORT (13.0 +/- 2.6 mg/dl to 19.2 +/- 3 mg/dl); the increase in blood pressure with LBPP (96 +/- 3 mm Hg to 112 +/- 4 mm Hg) was greater than that during control conditions. Renal plasma flow tended to display an interactive pattern across days, with a slight decline during LBPP (5%) and a slight elevation under control conditions (9%). On the LBPP day only, filtered Na+ declined (15 +/- I mEq/min to 12 +/- 1 mEq/min) as a function of reduced glomerular filtration rate (112 +/- 5 ml/min to 91 +/- 7 ml/min), blood volume decreased (by 2.7% +/- 0.7%), CO decreased (5.5 +/- 0.3 L/min to 4.7 +/- 0.3 L/min), and stroke volume declined (101 +/- 6 ml to 84 +/- 3 ml). On both days, NE increased (control, 221 +/- 23 pg/ml to 340 +/- 33 pg/ml; LBPP, 236 +/- 17 pg/ml to 369 +/- 31 pg/ml) and ANP increased (control, 47 +/- 7 pg/ml to 97 +/- 21 pg/ml; LBPP, 49 +/- 10 pg/ml to 104 +/- 30 pg/ml). We concluded that LBPP reduces renal sodium excretion. The mechanism for this reduction is not known, although it did occur in association with an increase in plasma renin activity, which in turn results from mechanical reduction of renal perfusion, stress-related CORT stimulation, a reflex-based elevation in peripheral vascular resistance leading to a reflex increase in plasma renin activity, or a combination of these.

MAST 96

The Military Anti-Shock Trouser, or MAST suit, is a controversial device that has been used to support blood pressure in hypotensive trauma patients. Most studies on humans have shown that the device has limited clinical utility. In this study, a telephone survey of all 50 State Emergency Medical Services was conducted to determine the nature and extent of MAST suit usage in the United States. The trend in MAST suit usage in San Diego County over the last 7 years was also analyzed. Thirty (60%) states still require MAST suits to be carried on ambulances. In San Diego County, MAST suit inflations for adult, hypotensive (systolic blood pressure < 90 mmHg,) blunt trauma patients has declined from 37% in 1987, to 2% in 1993. Despite a lack of data supporting efficacy in areas of severe hypotensive shock, blunt trauma, long transport times, and pelvic fractures, states continue to expend resources on the MAST suit. It is for this reason that we believe that the clinical use of the MAST suit should be based upon medical control philosophy rather than legislation.

Trauma in pregnancy

Trauma is a major cause of maternal death in pregnancy. The pregnant woman who has been involved in an episode leading to her arrival in an accident and emergency department presents with specific problems that often require specialist attention. The correct initial management of such patients should not be beyond the capabilities of an average trauma team and such management is clearly taught as part of the Advanced Trauma Life Support course now available in the UK. This review outlines the physiological changes associated with pregnancy that become important during resuscitation and definitive care. It discusses the presentation and management of specific problems, and the safety--or otherwise--of commonly administered drugs. Only the initial resuscitation of the patient is considered; specialist obstetric care is beyond the scope of the article.

Evaluation, treatment, and transport of pediatric patients with shock

Early recognition and correct treatment of shock remain the most important keys to preventing the death and disability frequently caused by this condition in children. The pediatrician plays a vital role in this process and in referral of the patient for transport to tertiary care centers, where shock is best managed. The transport environment creates special challenges in initial stabilization and ongoing treatment of shock. Discussion centers on clinical clues to recognition, on simple measures available to increase tissue oxygenation, and on the issues of pretransport and transport treatment. Support of airway and breathing, vascular access, and correct fluid therapy remain the cornerstones of successful treatment.

The impact of injury severity and prehospital procedures on scene time in victims of major trauma

STUDY OBJECTIVE

To evaluate the relationship among injury severity, prehospital procedures, and time spent at the scene by paramedics for victims of major trauma.

DESIGN

Retrospective study of 98 consecutive patients with an Injury Severity Score of more than 15 who were brought to a trauma center by fire department paramedics.

SETTING

A medium-sized metropolitan emergency medical services (EMS) system and a Level I trauma center.

RESULTS

There were 66 male and 32 female patients with a mean age of 34 years. Thirty-two patients (32.6%) died. Blunt and penetrating trauma accounted for 68.4% and 31.6% of cases, respectively. Thirty-three patients (33.7%) had successful advanced airway procedures, and 81 (82.7%) had at least one IV line started in the field. Analysis of scene time, prehospital procedures, and injury severity parameters revealed that more procedures were performed in the field on the more severely injured cases; that despite this, there was a trend toward shorter scene time for more severely injured patients; and that there was a mean scene time of 8.1 minutes. This is the shortest scene time reported to date for prehospital trauma care in an EMS system.

CONCLUSION

Extremely short scene times can be attained without foregoing potentially life-saving advanced life support interventions in an urban EMS system with strong medical control. In such a system, the most severely injured victims may spend less time at the scene although more procedures are performed on them.

Emergency management of blunt trauma in children

Apart from the trend to nonoperative treatment of blunt abdominal injuries, based on accurate CT diagnosis, most of the recent and anticipated changes in pediatric trauma are organizational. They include resuscitation and triage before hospitalization, the use of designated trauma centers, resuscitation by trauma teams, noninvasive diagnosis and monitoring, comprehensive pediatric intensive care, the use of objective measures of outcome, and improved rehabilitation programs (Templeton JM: personal communication). The treatment of individual cases is based on simple but well-established principles. The key steps in management are to recognize children with life-threatening injuries (on the basis of the mechanism of injury or a Pediatric Trauma Score less than or equal to 8 or a Revised Trauma Score less than or equal to 11), to support the function of vital organs by establishing and maintaining adequate respiratory gas exchange and circulation, and to identify all important injuries by thorough and ongoing assessment.

Prehospital care of the patient with an injured chest

The trauma patient with thoracic injury poses special problems for the paramedic. A chest injury frequently is a signal of other injury and alerts the paramedic to transport the patient to the regional trauma center, regardless of triage criteria applicable in any general area. In patients with chest injury, fluids should be judiciously administered, and pneumatic garments should NOT be applied. Trocar chest tubes should be avoided. Airway management is of prime importance, and the airway can be assured and protected by the paramedics. As time is of prime concern, the patient with thoracic injury should be transported as soon as possible to a regional trauma center. For distances of less than 35 miles, advanced life-support ground ambulances are preferable to air ambulances.