Cerebral blood flow changes during palpation of external airway structures in healthy volunteers.

INTRODUCTION: Previous studies demonstrate increased intracranial pressure (ICP) during direct laryngoscopy in patients with traumatic brain injury (TBI). Worse outcomes in TBI have been associated with increased ICP. It remains unclear if the same effect occurs during cricothyrotomy. We evaluated changes in cerebral blood flow and hemodynamic changes that occurred during preparation for cricothyrotomy in healthy volunteers. METHODS: An emergency medicine trainee performed routine anatomical procedural palpation with simultaneous transcranial doppler (TCD) measurements of cerebral blood flow velocities (CBFV) from bilateral middle cerebral arteries (MCAs). Mean arterial pressure (MAP) and heart rate (HR) were recorded throughout event. Our primary outcome was changes in pulsatility index (PI) and CBFV by TCD during palpation. TCD measurements were used as a surrogate for ICP. RESULTS: We enrolled 20 healthy volunteers for this study. No significant differences were found in pulsatility index [Right MCA -0.02 (95% confidence interval, -0.09 to 0.06), left MCA -0.02 (95% confidence interval, -0.011 to 0.07)] or mean CBFV [right MCA -0.70 mm/s (95% confidence interval, -10.15 to 8.75) left MCA -1.20 mm/s (95% confidence interval, -10.68 to 8.28)] during palpation. No significant change in HR was found [-1.1 bpm ((95% confidence interval, -2.4 to 0.1)]. A change in MAP was observed [1.3 mmHg (95% confidence interval, -0.1 to 2.4)]. CONCLUSIONS: In healthy individuals, no clinically significant change in cerebral blood flow velocities, ICP, or change heart rate was observed during palpation for cricothyrotomy.

The Prehospital Trauma Registry Experience With Intraosseous Access.

BACKGROUND: Peripheral intravenous (IV) cannulation is often difficult to obtain in a patient with hemorrhagic shock, delaying the appropriate resuscitation of critically ill patients. Intraosseous (IO) access is an alternative method. To date, few data exist on use of this procedure by ground forces in Afghanistan. Here, we compare patient characteristics and concomitant interventions among patients undergoing IO access versus those undergoing IV access only. METHODS: We obtained data from the Prehospital Trauma Registry (PHTR). When possible, patients were linked to the Department of Defense Trauma Registry for outcome data. To develop the cohorts, we searched for all patients with documented IO or IV access placement. Those with both IO and IV access documented were placed in the IO group. RESULTS: Of the 705 available patients in the PHTR, we identified 55 patients (7.8% of the population) in the IO group and 432 (61.3%) in the IV group. Among patients with documentation of access location, the most common location was the tibia (64.3%; n = 18). Compared with patients with IV access, those who underwent IO access had higher urgent evacuation rates (90.9% versus 72.4%; p = .01) and air evacuation rates (58.2% versus 14.8%; p < .01). The IO cohort had significantly higher rates of interventions for hypothermia, chest seals, chest tubes, needle decompressions, and tourniquets, but a significantly lower rate of analgesic administration (ρ ≤ .05). CONCLUSION: Within the registry, IO placement was relatively low (<10%) and used in casualties who received several other life-saving interventions at a higher rate than casualties who had IV access. Incidentally, lower proportions of analgesia administration were detected in the IO group compared with the IV group, despite higher intervention rates.

Battlefield Analgesia: Adherence to Tactical Combat Casualty Care Guidelines.

BACKGROUND: Low rates of prehospital analgesia, as recommended by Tactical Combat Casualty Care (TCCC) guidelines, have been demonstrated in the Joint Theaters combat setting. The reasons for this remain unclear. This study expands on previous reports by evaluating a larger prehospital dataset for determinants of analgesia administration. METHODS: This was part of an approved quality assurance project evaluating adherence to TCCC guidelines across multiple modalities. Data were from the Prehospital Trauma Registry, which existed from January 2013 through September 2014, and comprises data from TCCC cards, Department of Defense 1380 forms, and after-action reports to provide real-time feedback to units on prehospital medical care. RESULTS: Of 705 total patient encounters, there were 501 documented administrations of analgesic medications given to 397 patients. Of these events, 242 (34.3%) were within TCCC guidelines. Special Operations Command had the highest rate of overall adherence, but rates were still low (68.5%). Medical officers had the highest rates of overall administration. The low rates of administration and adherence persisted across all subgroups. CONCLUSION: Rates of analgesia administration remained low overall and in subgroup analyses. Medical officers appeared to have higher rates of compliance with TCCC guidelines for analgesia administration, but overall adherence to TCCC guidelines was low. Future research will be aimed at finding methods to improve administration and adherence rates.

Prehospital Resuscitation Performed on Hypotensive Trauma Patients in Afghanistan: The Prehospital Trauma Registry Experience.

INTRODUCTION: Hemorrhage is the leading cause of potentially preventable death on the battlefield. Hypotension in the setting of trauma portends a higher rate of mortality. We describe the interventions for trauma-related hypotension performed in the prehospital combat setting in accordance with Tactical Combat Casualty Care (TCCC) guidelines. MATERIALS AND METHODS: We searched the Prehospital Trauma Registry for casualties from January 2013 to September 2014. Within that group, we searched for all casualties with documented hypotension by either measured systolic blood pressure ≤90 mmHg or a weak or absent radial pulse documented by the prehospital provider. We used descriptive statistics to analyze the interventions performed in our study sample. RESULTS: Of the 705 casualties available for query, 134 (19.0%) casualties with documented hypotension met inclusion criteria. Most casualties with hypotension had an alert mental status (70.1%), had a medical officer in their chain of care (59.0%), were Afghan (64.2%), and evacuated on an urgent status (78.4%). Explosives were the most frequent mechanism of injury (50.7%). There were 42 fluid administrations documented on 33 (24.6%) casualties. The most common fluid administered was normal saline (52.4%) followed by hetastarch solution (33.3%). There was one documented use of a fluid warmer in this cohort. One subject received four units of packed red blood cells. No other casualties had documented blood product administration. There were no documented administrations of PlasmaLyte. There were four casualties that received lactated Ringer's. CONCLUSION: Most casualties with documented hypotension after trauma in the Prehospital Trauma Registry did not receive prehospital blood or fluid intervention. Of the interventions performed, most did not match with contemporary TCCC guidelines.

Prehospital Administration of Antibiotic Prophylaxis for Open Combat Wounds in Afghanistan: 2013-2014.

BACKGROUND: Military operations place injured Servicemembers at high risk for open wounds. Austere environments and initial wound contamination increase the risk for infection. Wound infections continue to cause significant morbidity among injured Servicemembers. Limited evidence suggests that early antibiotic therapy for open wounds reduces infection rates. METHODS: We obtained data from the Prehospital Trauma Registry (PHTR) from January 2013 through September 2014. This database includes data from Tactical Combat Casualty Care (TCCC) cards, Department of Defense 1380 forms, and after-action reports to provide near-real-time feedback to units on prehospital medical care. We evaluated whether patients with open wounds received antibiotics in accordance with TCCC guidelines. Low adherence was defined at less than 80%. RESULTS: In this data set, overall, prefixed facility providers administered antibiotics to 54.0% of patients with an open combat wound. Of the antibiotics given, 11.1% were within TCCC guidelines. The relatively low administration and adherence rates persisted across subgroup analyses. CONCLUSION: Overall, relatively few patients with open combat wounds receive antibiotic administration as recommended by TCCC guidelines. In the group that received antibiotics, few received the specific antibiotics recommended by TCCC guidelines. The development of strategies to improve adherence to these TCCC recommendations is a research priority.

Chest Seal Placement for Penetrating Chest Wounds by Prehospital Ground Forces in Afghanistan.

BACKGROUND: Thoracic trauma represents 5% of all battlefield injuries. Communicating pneumothoraces resulting in tension physiology remain an important etiology of prehospital mortality. In addressing penetrating chest trauma, current Tactical Combat Casualty Care (TCCC) guidelines advocate the immediate placement of a vented chest seal device. Although the Committee on TCCC (CoTCCC) has approved numerous chest seal devices for battlefield use, few data exist regarding their use in a combat zone setting. OBJECTIVE: To evaluate adherence to TCCC guidelines for chest seal placement among personnel deployed to Afghanistan. METHODS: We obtained data from the Prehospital Trauma Registry (PHTR). Joint Trauma System personnel linked patients to the Department of Defense Trauma Registry, when available, for outcome data upon reaching a fixed facility. RESULTS: In the PHTR, we identified 62 patients with documented gunshot wound (GSW) or puncture wound trauma to the chest. The majority (74.2%; n = 46) of these were due to GSW, with the remainder either explosive-based puncture wounds (22.6%; n = 14) or a combination of GSW and explosive (3.2%; n = 2). Of the 62 casualties with documented GSW or puncture wounds, 46 (74.2%) underwent chest seal placement. Higher proportions of patients with medical officers in their chain of care underwent chest seal placement than those that did not (63.0% versus 37.0%). The majority of chest seals placed were not vented. CONCLUSION: Of patients with a GSW or puncture wound to the chest, 74.2% underwent chest seal placement. Most of the chest seals placed were not vented in accordance with guidelines, despite the guideline update midway through the study period. These data suggest the need to improve predeployment training on TCCC guidelines and matching of the Army logistical supply chain to the devices recommended by the CoTCCC.

QuikClot® Combat Gauze® Use by Ground Forces in Afghanistan The Prehospital Trauma Registry Experience.

BACKGROUND: QuikClot® Combat Gauze® (QCCG) was fielded in 2008 to replace previous generations of hemostatic products. To the best of our knowledge, despite nearly a decade of use, there are no published data on use among US combatant forces. We describe the use of QCCG by ground forces in Afghanistan and compare patients who received QCCG compared with the remaining population in the database who did not receive QCCG. METHODS: Data were obtained from the Prehospital Trauma Registry (PHTR). Joint Trauma System personnel linked patients to the Department of Defense Trauma Registry (DODTR) for outcome data, when available, upon reaching a fixed facility. RESULTS: Of the 705 patients within the entire PHTR, 118 (16.7%) had documented use of QCCG. Most patients (69.5%) were Afghan; all were male. Lower extremities accounted for the most common site of application (39.7%). Hemorrhage control occurred in 88.3% of encounters with hemorrhage control status documented. Patients receiving QCCG generally had higher rates of concomitant interventions. Of the 705 patients, 190 were linkable to the DODTR for outcome data; 25 of the 28 (89.3%) in the QCCG group were discharged alive compared with 153 of the 162 (94.4%) in the non-QCCG group (ρ = .300). CONCLUSION: QCCG appears to have common use on the battlefield as a concomitant intervention for obtaining hemorrhage control. Patients receiving QCCG had higher rates of gunshot wounds compared with the baseline population and were generally sicker. Hemorrhage control success was like that reported in other military and civilian settings.

Effect of pain and analgesia on compensatory reserve.

BACKGROUND: The measurement of the body's capacity to compensate for reduced blood volume can be assessed with a compensatory reserve measurement (CRM). The CRM, which is calculated from changes in features of the arterial waveform, represents the integration of compensatory mechanisms during states of low tissue perfusion and oxygenation, such as hemorrhage. This study was designed to test the hypothesis that pain which activates compensatory mechanisms and analgesia that result in reduced blood pressure are associated with lower compensatory reserve. This study evaluated CRM in obstetric patients during labor as pain intensity increased from no pain to severe pain and compared CRM before and after epidural anesthesia. METHODS: CRM was calculated from a finger pulse oximeter placed on the patient's index finger and connected to the DataOx monitor in healthy pregnant women (n = 20) before and during the active labor phase of childbirth. RESULTS: As pain intensity, based on an 11-point scale (0, no pain; 10, worst pain), increased from 0 to 8.4 ± 0.9 (mean ± SD), CRM was not affected (81 ± 10% to 82 ± 13%). Before analgesia, CRM was 84 ± 10%. CRM at 10 minutes, 20 minutes, 30 minutes, 40 minutes, 50 minutes, and 60 minutes after analgesia was 82 ± 11%, 83 ± 14%, 83 ± 15%, 86 ± 12%, 89 ± 9%, and 87 ± 10%, respectively. There was a transient 2% reduction followed by a 5% increase in CRM from before to after epidural anesthesia (p = 0.048). Pain scores before and after analgesia were 7 ± 2 and 1 ± 1, respectively (p < 0.001). CONCLUSION: These results indicate that pain and analgesia contribute minimally, but independently to the reduction in compensatory reserve associated with trauma and hemorrhage. As such, our findings suggest that analgesia can be safely administered on the battlefield while maintaining the maximal capacity of mechanisms to compensate for blood loss. LEVEL OF EVIDENCE: Diagnostic study, level II.