Telementorship in Underway Naval Operations: Leveraging Operational Virtual Health for Tactical Combat Casualty Care

BACKGROUND

Virtual health (VH) may enhance mentorship to remote first responders. We evaluated the feasibility of synchronous bidirectional VH to mentor life-saving procedures performed by deployed novice providers.

METHODS

Video teleconferencing (VTC) was established between the USNS Mercy (T-AH 19) underway in the Pacific Ocean to Naval Medical Center San Diego using surgeon teleconsultation. The adult simulated clinical vignette included injuries following a shipboard explosion with subsequent fire. The pediatric simulated vignette included injuries that resulted from an improvised explosive device (IED) blast. Using VTC, augmented reality (AR) goggles, and airway simulation equipment, corpsmen (HMs) received visual cues to perform advanced life-saving procedures.

RESULTS

In adult scenarios, 100% of novice hospital HMs performed tasks on first attempt (n = 12). Mean time for tourniquet placement was 46 seconds (standard deviation [SD], 19 seconds); needle thoracostomy, 70 seconds (SD, 67 seconds); tube thoracostomy, 313 seconds (SD, 152 seconds); and cricothyroidotomy, 274 seconds (SD, 82 seconds). In pediatric scenarios, 100% of novice HMs performed tasks on first attempt (n = 5). Mean time for tube thoracostomy completion was 532 seconds (SD, 109 seconds).

CONCLUSION

VH can enhance the training and delivery of trauma care during prolonged field care in resource-limited settings.

A tale of two centers: Is low-molecular-weight heparin really superior for prevention of posttraumatic venous thromboembolism?

BACKGROUND

Low-molecular-weight heparin (LMWH) is widely used for venous thromboembolism chemoprophylaxis following injury. However, unfractionated heparin (UFH) is a less expensive option. We compared LMWH and UFH for prevention of posttraumatic deep venous thrombosis (DVT) and pulmonary embolism (PE).

METHODS

Trauma patients 15 years or older with at least one administration of venous thromboembolism chemoprophylaxis at two level I trauma centers with similar DVT-screening protocols were identified. Center 1 administered UFH every 8 hours for chemoprophylaxis, and center 2 used twice-daily antifactor Xa-adjusted LMWH. Clinical characteristics and primary chemoprophylaxis agent were evaluated in a two-level logistic regression model. Primary outcome was incidence of DVT and PE.

RESULTS

There were 3,654 patients: 1,155 at center 1 and 2,499 at center 2. The unadjusted DVT rate at center 1 was lower than at center 2 (3.5% vs. 5.0%; p = 0.04); PE rates did not significantly differ (0.4% vs. 0.6%; p = 0.64). Patients at center 2 were older (mean, 50.3 vs. 47.3 years; p < 0.001) and had higher Injury Severity Scores (median, 10 vs. 9; p < 0.001), longer stays in the hospital (mean, 9.4 vs. 7.0 days; p < 0.001) and intensive care unit (mean, 3.0 vs. 1.3 days; p < 0.001), and a higher mortality rate (1.6% vs. 0.6%, p = 0.02) than patients at center 1. Center 1's patients received their first dose of chemoprophylaxis earlier than patients at center 2 (median, 1.0 vs. 1.7 days; p < 0.001). After risk adjustment and accounting for center effects, primary chemoprophylaxis agent was not associated with risk of DVT (odds ratio, 1.01; 95% confidence interval, 0.69-1.48; p = 0.949). Cost calculations showed that UFH was less expensive than LMWH.

CONCLUSION

Primary utilization of UFH is not inferior to LMWH for posttraumatic DVT chemoprophylaxis and rates of PE are similar. Given that UFH is lower in cost, the choice of this chemoprophylaxis agent may have major economic implications.

LEVEL OF EVIDENCE

Prognostic and epidemiological, level II; Therapeutic, level III.

Is cerebral perfusion maintained during full and partial resuscitative endovascular balloon occlusion of the aorta in hemorrhagic shock conditions?

BACKGROUND

Partial resuscitative endovascular balloon occlusion of the aorta (pREBOA) is a technology that occludes aortic flow and allows for controlled deflation and restoration of varying distal perfusion. Carotid flow rates (CFRs) during partial deflation are unknown. Our aim was to measure CFR with the different pREBOA balloon volumes and correlate those to the proximal mean arterial pressure (PMAP) and a handheld pressure monitoring device (COMPASS; Mirador Biomedical, Seattle, WA).

METHODS

Ten swine underwent a hemorrhagic injury model with carotid and iliac arterial pressures monitored via arterial lines. Carotid and aortic flow rates were monitored with Doppler flow probes. A COMPASS was placed to monitor proximal pressure. The pREBOA was inflated for 15 minutes then partially deflated for an aortic flow rate of 0.7 L/min for 45 minutes. It was then completely deflated. Proximal mean arterial pressures and CFR were measured, and correlation was evaluated. Correlation between CRF and COMPASS measurements was evaluated.

RESULTS

Carotid flow rate increased 240% with full inflation. Carotid flow rate was maintained at 100% to 150% of baseline across a wide range of partial deflation. After full deflation, CFR transiently decreased to 45% to 95% of baseline. There was strong positive correlation (r > 0.85) between CFR and PMAP after full inflation, and positive correlation with partial inflation (r > 0.7). Carotid flow rate had strong correlation with the COMPASS with full REBOA (r > 0.85) and positive correlation with pREBOA (r > 0.65).

CONCLUSION

Carotid flow rate is increased in a hemorrhagic model during full and partial inflation of the pREBOA and correlates well with PMAP. Carotid perfusion appears maintained across a wide range of pREBOA deflation and could be readily monitored with a handheld portable COMPASS device instead of a standard arterial line setup.

Real-time bedside management and titration of partial resuscitative endovascular balloon occlusion of the aorta without an arterial line: Good for pressure, not for flow!

BACKGROUND

Partial resuscitative endovascular balloon occlusion of the aorta (pREBOA) attempts to minimize ischemia/reperfusion injury while controlling hemorrhage. There are little data on optimal methods to evaluate and titrate partial flow, which typically requires invasive arterial line monitoring. We sought to examine the use of a miniaturized handheld digital pressure device (COMPASS; Mirador Biomedical, Seattle, WA) for pREBOA placement and titration of flow.

METHODS

Ten swine underwent standardized hemorrhagic shock. Carotid and iliac pressures were monitored with both arterial line and COMPASS devices, and flow was monitored by aortic and superior mesenteric artery flow probes. Partial resuscitative endovascular balloon occlusion of the aorta was inflated to control hemorrhage for 15 minutes before being deflated to try targeting aortic flow of 0.7 L/min (using only the COMPASS device) by an operator blinded to the arterial line pressures and aortic flow. Correlations between COMPASS and proximal/distal arterial line were evaluated, as well as actual aortic flow.

RESULTS

There was strong correlation between the distal mean arterial pressure (MAP) and the distal COMPASS MAP (r = 0.979, p < 0.01), as well as between the proximal arterial line and the proximal COMPASS on the pREBOA (r = 0.989, p < 0.01). There was a significant but weaker correlation between the distal compass MAP reading and aortic flow (r = 0.47, p < 0.0001), although it was not clinically significant and predicted flow was not achieved in a majority of the procedures. Of 10 pigs, survival times ranged from 10 to 120 minutes, with a mean survival of 50 minutes, and 1 pig surviving to 120 minutes.

CONCLUSION

Highly reliable pressure monitoring is achieved proximally and distally without arterial lines using the COMPASS device on the pREBOA. Despite accurate readings, distal MAPs were a poor indicator of aortic flow, and titration based upon distal MAPs did not provide reliable results. Further investigation will be required to find a suitable proxy for targeting specific aortic flow levels using pREBOA.

Outcomes after single-look trauma laparotomy: A large population-based study

BACKGROUND

Outcomes following damage control laparotomy for trauma have been studied in detail. However, outcomes following a single operation, or "single-look trauma laparotomy" (SLTL), have not. We evaluated the association between SLTL and both short-term and long-term outcomes in a large population-based data set.

METHODS

The California Office of Statewide Health Planning and Development patient discharge database was evaluated for calendar years 2007 through 2014. Injured patients with SLTL during their index admission were identified using International Classification of Diseases, Ninth Revision, Clinical Modification procedure codes. Diagnosis and procedure codes were used to identify specific abdominal organ injuries, surgical interventions, and perioperative complications. Subsequent acute care admissions were examined for postoperative complications and related surgical interventions. Clinical characteristics, injuries, surgical interventions, and outcomes were analyzed by mechanism of injury.

RESULTS

There were 2113 patients with SLTL during their index admission; 712 (33.7%) had at least one readmission to an acute care facility. Median time to first readmission was 110 days. Penetrating mechanism was more common than blunt (60.6% vs. 39.4%). Compared to patients with penetrating injury, blunt-injured patients had a significantly higher median Injury Severity Score (9 vs. 18, p < 0.0001) and a significantly higher mortality rate during the index admission (4.1% vs. 27.0%, p < 0.0001). More than 30% of SLTL patients requiring readmission had a surgery-related complication. The most common primary reasons for readmission were bowel obstruction (17.7%), incisional hernia (11.8%), and infection (9.1%). There was no significant association between mechanism of injury and development of surgery-related complications requiring readmission.

CONCLUSIONS

Patients with SLTL had postinjury morbidity and mortality, and more than 30% required readmission. Complication rates for SLTL were comparable to those reported for emergency general surgery procedures. Patients should be educated on signs and symptoms of the most common complications before discharge following SLTL. Further investigation should focus on the factors associated with the development of these complications.

LEVEL OF EVIDENCE

Prognostic and epidemiologic study, level III.

Radiofrequency Identification of the ER-REBOA: Confirmation of Placement Without Fluoroscopy

INTRODUCTION

Non-compressible torso hemorrhage accounts for 70% of battlefield deaths. Resuscitative endovascular balloon occlusion of the aorta (REBOA) is an emerging technology used to mitigate massive truncal hemorrhage. Use of REBOA on the battlefield is limited by the need for radiographic guided balloon placement. Radiofrequency identification (RFID) is a simple, portable, real-time technology utilized to detect retained sponges during surgery. We investigated the feasibility of RFID to confirm the placement of ER-REBOA.

MATERIALS AND METHODS

This was a single-arm prospective proof-of-concept experimental study approved by the institutional review board at Naval Medical Center San Diego. The ER-REBOA (Prytime Medical Devices, Inc, Boerne, TX, USA) was modified by placement of a RFID tag. The tagged ER-REBOA was placed in zone I or zone III of the aorta in a previously perfused cadaver. Exact location was documented with X-ray. Five blinded individuals used the RF Assure Detection System (Medtronic, Minneapolis, MN, USA) handheld detection wand to predict catheter tip location from the xiphoid process (zone I) or pubic tubercle (zone III).

RESULTS

In zone I, actual distance (Da) of the catheter tip was 11 cm from the xiphoid process. Mean predicted distance (Dp) from Da was 1.52 cm (95% CI 1.19-1.85). In zone III, Da was 14 cm from the pubic tubercle. Mean Dp from Da was 4.11 cm (95% CI 3.68-4.54). Sensitivity of detection was 100% in both zones. Specificity (Defined as Dp within 2 cm of Da) was 86% in zone I and 16% in zone III.

CONCLUSIONS

Using RFID to confirm the placement of ER-REBOA is feasible with specificity highest in zone I. Future work should focus on refining this technology for the forward-deployed setting.

Association of Operative Repair Type and Trauma Center Designation With Outcomes in Ruptured Abdominal Aortic Aneurysm Repair

OBJECTIVE

Open repair of ruptured abdominal aortic aneurysm (rAAA) has shown improved outcomes at trauma centers. Whether the benefit of trauma center designation extends to endovascular repair of rAAA is unknown.

METHODS

Retrospective cohort study using the California Office of Statewide Health Planning and Development 2007 to 2014 discharge database to identify patients with rAAA. Data included demographic and admission factors, discharge disposition, International Classification of Diseases, Ninth Revision, Clinical Modification codes, and hospital characteristics. Hospitals were categorized by trauma center designation and teaching hospital status. The effect of repair type and trauma center designation (level I, level II, or other-other trauma centers and nondesignated hospitals) was evaluated to determine rates and risks of 9 postoperative complications, in-hospital mortality, and 30-day postdischarge mortality.

RESULTS

Of 1941 rAAA repair patients, 61.2% had open and 37.8% had endovascular; 1.0% had both. Endovascular repair increased over the study interval. Hospitals were 12.0% level I, 25.0% level II, and 63.0% other. A total of 48.7% of hospitals were teaching hospitals (level I, 100%; level II, 42.2%; and other, 41.8%). Endovascular repair was significantly more common at teaching hospitals (41.5% vs 34.3%, P < .001) and was the primary repair method at level I trauma centers (P < .001). Compared with open repair, endovascular repair was protective for most complications and in-hospital mortality. The risk for in-hospital mortality was highest among endovascular patients at level II trauma centers (hazard ratio 1.67, 95% confidence interval [CI]: 0.95-2.92) and other hospitals (hazard ratio 1.66, 95% CI: 1.01-2.72).

CONCLUSIONS

Endovascular repair overall was associated with a lower risk of adverse outcomes. Endovascular repair at level I trauma centers had a lower risk of in-hospital mortality which may be a result of their teaching hospital status, organizational structure, and other factors. The weight of the contributions of such factors warrants further study.

Evaluating surgical outcomes in pediatric extremity vascular trauma

BACKGROUND

The purpose of this study was to evaluate the epidemiology and management of pediatric vascular extremity trauma to assess injury patterns and other factors that may contribute to poor outcomes.

METHODS

Using the California Office of Statewide Health Planning and Development discharge database, we identified pediatric patients with extremity arterial trauma admitted to acute-care hospitals from 2007 to 2014. Demographics, management patterns, and outcomes were collected and analyzed.

RESULTS

A total of 775 patients were treated for an extremity arterial injury. Overall, 40% were admitted to pediatric trauma centers and 39% to adult trauma centers. Management was predominantly by open surgical repair. Injury to the common femoral artery was associated with mortality (Hazard Ratio 3.9; 95% CI 1.1-14.5; p < 0.05). Popliteal artery injuries (Odds Ratio [OR] 4.8; 95% CI 1.2-19.9; p < 0.05) and anterior tibial artery injuries (OR 7.1; 95% CI 1.4-37.3; p < 0.05) had an increased risk of amputation. There was no difference in amputation or mortality rates by hospital category.

CONCLUSIONS

Pediatric extremity arterial injuries are rare. In California, outcomes are similar by hospital type. Common femoral artery injuries are associated with an increased risk of mortality, while popliteal and anterior tibial artery injuries are associated with an increased risk of amputation.

TYPE OF STUDY

Prognosis Study.

LEVEL OF EVIDENCE

Level III.

Association of complicated gallstone disease in pregnancy and adverse birth outcomes

BACKGROUND

Complicated gallstone disease (CGD) is a common condition requiring intervention during pregnancy to avert adverse birth outcomes (ABO).

METHODS

Cohort study using the California OSHPD 2007-2014 database. Records of pregnant patients were analyzed for gallbladder calculus within four months of delivery. Biliary system interventions were evaluated as the primary exposure.

RESULTS

Of 7,597 patients, those with CGD had a greater likelihood of biliary system procedures than those with uncomplicated gallstone disease (36.6% vs. 2.5%, p < 0.001). Patients with CGD also had increased odds of ABO (OR 2.02, 95% CI, 1.48-2.76). Compared to patients without biliary system procedures, those with interventions for gallstones had an OR of 3.46 (95% CI, 2.48-4.82) for ABO. After adjustment, biliary system intervention for CGD had an even greater risk of ABO (OR 4.26, 95% CI, 2.86-6.35).

CONCLUSIONS

The risk of ABO is significantly increased in women with CGD and intervention for gallstones.

Outcomes in adhesive small bowel obstruction from a large statewide database: What to expect after nonoperative management

BACKGROUND

Although adhesive small-bowel obstruction (ASBO) is frequently managed nonoperatively, little is known regarding outcomes on readmission following this approach. Using a large population-based dataset, we evaluated risk factors for operative intervention and mortality at readmission in patients with ASBO who were initially managed nonoperatively.

METHODS

The ASBO patients were identified in the California Office of Statewide Health Planning and Development 2007 to 2014 patient discharge database. Patients who were managed operatively at index admission or had an International Classification of Diseases, Ninth Revision, Clinical Modification diagnosis code for nonadhesive obstructive small bowel disease were excluded. Associations between risk factors and both operative intervention and death following readmission were evaluated using survival analysis.

RESULTS

Among 15,963 ASBO patients, 3,103 (19.4%) had at least one readmission. The 1,069 (34.5%) who received an operation during their first readmission presented sooner (175 days vs. 316 days, p < 0.001) and were more likely to die during that readmission (5.2% vs. 0.7%, p < 0.001). Operative management at first readmission was associated with younger age, fewer comorbidities, and shorter times to readmission. Patients operatively managed at first readmission had longer times to second readmission compared with nonoperative patients. Stratified analyses using nonoperative patients as the reference over the study period revealed that patients who underwent lysis of adhesions and bowel resection were 5.04 times (95% confidence interval [CI], 2.82-9.00) as likely to die while those who underwent lysis only were 2.09 times (95% CI, 1.14-3.85) as likely to die. Patients with bowel resection only were at an increased risk for subsequent interventions beyond the first readmission (hazard ratio, 1.79; 95% CI, 1.11-2.87).

CONCLUSION

In a large cohort readmitted for ASBO and initially managed nonoperatively, subsequent operative intervention conferred a greater risk of death and a longer time to readmission among survivors. Prospective research is needed to further delineate outcomes associated with initial nonoperative management of ASBO.

LEVEL OF EVIDENCE

Prognostic and epidemiological, level III.