Journal of special operations medicine : a peer reviewed journal for SOF medical professionals最新文献

Background: Among individuals with prior exertional heat illness (EHI), heat tolerance testing (HTT) may inform risk and return to duty/activity. However, little is known about HTT's predictive validity, particularly for EHI recurrence. Our project sought to demonstrate the predictive validity of HTT in EHI recurrence and HTT's utility as a diagnostic tool in exertional heat stroke (EHS).

Methods: Participants with prior EHS were recruited for the study by a physician's referral and were classified as heat tolerant or intolerant after completing demographics and an HTT. Participants were further categorized as single/simple (SS) EHI or recurrent/complex (RC) EHI by conducting a retrospective record review of the following two years. We calculated the positive (PPV) and negative predictive values (NPV) of HTT.

Results: The retrospective review of HTT records was used to categorize 44% of Servicemembers as RC, with 77% classified as heat tolerant, 14% as heat intolerant, and 9% as borderline. When borderline cases were classified as heat intolerant, HTT had a high NPV, indicating a high probability that heat-tolerant individuals did not have recurrent EHI. When borderline cases were classified as heat tolerant, NPV and sensitivity decreased while specificity increased.

Conclusion: We demonstrated that the HTT had a 100% NPV for future EHI over two years of follow-up for Servicemembers with a history of recurrent heat injury and negative HTT results. An HTT can provide critical data points to inform return to duty decisions and timelines by predicting the risk of EHI recurrence.

Background: Tactical Combat Casualty Care (TCCC) guidelines recognize low-titer group O whole blood (LTOWB) as the resuscitative fluid of choice for combat wounded. Utilization of prescreened LTOWB in a walking blood bank (WBB) format has been well described by the Ranger O low-titer blood (ROLO) and the United States Marine Corps Valkyrie programs, but it has not been applied to the maritime setting.

Methods: We describe three WBB experiences of an expeditionary resuscitative surgical system (ERSS) team, attached to three nontraditional maritime medical receiving platforms, over 6 months.

Results: Significant variations were identified in the number of screened eligible donors, the number of LTOWB donors, and the timely arrival at WBB activation sites between the platforms. Overall, 95% and 84% of the screened eligible group O blood donors on the Arleigh Burke Class Destroyer (DDG) and Nimitz Class Aircraft Carrier (CVN), respectively, were determined to be LTOWB. However, only 37% of the eligible screened group O blood donors aboard the Harper's Ferry Class Dock Landing Ship (LSD) were found to be LTOWB. Of the eligible donors, 66% did not complete screening, with 52% citing a correctable reason for nonparticipation.

Conclusion: LTOWB attained through WBBs may be the only practical resuscitative fluid on maritime platforms without inherent blood product storage capabilities to perform remote damage control resuscitation. Future efforts should focus on optimizing WBBs through capability development, education, and training efforts.

Background: Fast and reliable blood collection is critical to emergency walking blood banks (WBB) because mortality significantly declines when blood is quickly administered to a warfighter with hemorrhagic shock. Phlebotomy for WBB is accomplished via either the "straight stick" (SS) or "ruggedized lock" (RL) method. SS comprises a 16-gauge phlebotomy needle connected to a blood collection bag via tubing. The RL device collects blood through the same apparatus, but has a capped, intravenous (IV) catheter between the needle and the donor's arm. This is the first study to compare these two methods in battlefield-relevant metrics.

Methods: Military first responders and licensed medical providers (N=86) were trained in SS and RL as part of fresh whole blood training exercises. Outcomes included venipuncture success rates, time to IV access, blood collection times, total time, and user preferences, using a within-subjects crossover design. Data were analyzed using ANOVA and nonparametric statistics at p<0.05.

Results: SS outperformed RL in first venipuncture success rates (76% vs. 64%, p=0.07), IV access times (448 [standard error of the mean; SE 23] vs. 558 [SE 31] s, p<0.01), and blood collection bag fill times (573 [SE 48] vs. 703 [SE 44] s, p<0.05), resulting in an approximate 3.5-minute faster time overall. Survey data were mixed, with users perceiving SS as simpler and faster, but RL as more reliable and secure.

Conclusion: SS is optimal when timely collection is imperative, while RL may be preferable when device stability or replacing the collection bag is a consideration.

Background: Veno-venous extracorporeal membrane oxygenation (VV ECMO) is a low-frequency, high-intensity procedure used for severe lung illness or injury to facilitate rapid correction of hypoxemia and respiratory acidosis. This technology is more portable and extracorporeal support is more frequently performed outside of the hospital. Future conflicts may require prolonged causality care and more specialized critical care capabilities including VV ECMO to improve patient outcomes. We used an expert consensus survey based on a developed bifemoral VV ECMO cannulation checklist with an operational focus to establish a standard for training, validation testing, and sustainment.

Methods: A 36-item procedural checklist was provided to 14 experts from multiple specialties. Using the modified Delphi method, the checklist was serially modified based on expert feedback.

Results: Three rounds of the study were performed, resulting in a final 32-item checklist. Each item on the checklist received at least 70% expert agreement on its inclusion in the final checklist.

Conclusion: A procedural performance checklist was created for bifemoral VV ECMO using the modified Delphi method. This is an objective tool to assist procedural training and validation for medical providers performing VV ECMO in austere environments.

Building upon our strategic framework and operational model, we will discuss findings from our ethnographic study, entitled: "The Impact of Catastrophic Injury Exposure on Resilience in Special Operations Surgical Teams (SOSTs)," to explain the tactical nature and importance of social determinants within our new characterization of unconventional resilience. Our fourth paper in this series, will explain how bonding patterns establish the quality of intra- and interpersonal connections that create a tensive conduit for the pressure of performance within our operational model, allowing for dynamic freedom of maneuver to take place in ambiguity. We will use qualita- tive quotes to illustrate various ways SOST medics relate to themselves, other people, and the Special Operations Forces (SOF) culture. To achieve our goals, we will: 1) provide an in- troduction to social determinants as tactical engagement with unconventional resilience; 2) define the social determinant of bonding patterns as extrapolated from qualitative data as well as use qualitative data to thematize various types of bonding patterns; and 3) relate tactical engagement with bonding pat- terns to our metaphor of bag sets. We conclude by gesturing to the importance of bonding patterns in orienting SOF medics' proprioception and kinesthesia in the SOF performance space.

Aim: The objective of the study was to evaluate the use of tourniquets in the Russo-Ukrainian war.

Methods: The type, number, and duration of tourniquets per limb, the clinical course of limb injuries, and the functional status of the injured limbs during the 24 hours post-injury were evaluated in military hospital facilities for the period of 2014-2022. Statistical frequencies and variances were analyzed.

Results: During active hostilities, the medical units of the Southern Operational Command received 2,496 patients with limb injuries that required the application of tourniquets. Lower extremity injuries were predominantly observed (84.4%). A single tourniquet was used in 1,538 cases (61.6%), whereas two tourniquets were used in 533 (21.4%), and three tourniquets in 425 cases (17.0%). During the 2014- 2021 period, Esmarch's tourniquet was most commonly used. However, in 2022, it was mostly replaced by the Combat Application Tourniquet and similar systems (e.g., Sich, Dnipro). The duration of the tourniquet use ranged from 50 to 380 minutes (mean 205.9 [standard error 8.1] min), which prolonged ischemia in a significant number of cases. Limb amputations, mainly due to extensive necrosis, were performed in 92 cases (3.7%). In addition to 101 deaths (4.0% of patients), 11 cases of severe tourniquet syndrome were encountered. The limb was salvaged in 9 cases (81.8%).

Conclusion: Prompt triage and evacuation of injured combatants can save affected limbs, even when the duration of tourniquet use exceeds 2 hours. Tourniquet syndrome can be prevented using a hemostatic tourniquet.

Background: The U.S. Military needs fast-acting, non-opioid solutions for battlefield pain. The U.S. Military recently used morphine auto-injectors, which are now unavailable. Off-label ketamine and oral transmucosal fentanyl citrate use introduces challenges and is therefore uncommon among conventional forces. Sublingual suftentanil is the only recent pain medication acquired to fill this gap. Conversely, methoxyflurane delivered by a handheld inhaler is promising, fast-acting, and available to some partner forces. We describe methoxyflurane use reported in the Department of Defense Trauma Registry (DODTR).

Methods: We requested all available DODTR encounters from 2007 to 2023 with a documented intervention or assessment within the first 72 hours of care. We analyzed casualties who received methoxyflurane in the prehospital setting using descriptive statistics.

Results: There were 22 encounters with documented methoxyflurane administration. The median patient age was 23 (range 21-31) years. All were men. The largest proportion was partner force (50%), followed by U.S. Military (27%). Most (64%) sustained battle injuries. Explosives were the most common mechanism of injury (46%), followed by firearms (23%). The median injury severity score was 5 (range 1-17). The most frequent injuries were serious injuries to the extremities (27%), and 23% of patients (5) received a tourniquet. One-half of the casualties received concomitant pain medications. Only three casualties had multiple pain scores measured, with a median pain score change of -3 on a scale of 10.

Conclusion: Methoxyflurane use in deployed combat shows both feasibility and usability for analgesia.

Background: Recommendations for optimal temperature and humidity for sterile instrument storage vary according to different sources. Furthermore, there are limited data comparing methods of packing smaller, lightweight, low-profile instruments. The purpose of this study was to compare sterile peel packaging and sterile cellulose wrapping for sterile instrument storage in an austere environment characterized by elevated temperature and humidity.

Methods: Stainless steel screws were sterilized and stored in either sterile peel packaging, sterile cellulose wrapping, or no packaging. Four groups were evaluated. Group 1 consisted of four screws in a sterile peelpack envelope and served as a time-zero control. Group 2 consisted of two groups of five screws, each packaged with blue sterilization cellulose wrap. Group 3 consisted of two groups of five screws, each packaged in sterile peel-pack envelopes. Group 4 consisted of 10 non-sterile unpackaged screws, which served as controls. Screws from groups 2, 3, and 4 were then cultured for 6 and 12 weeks. Temperature and humidity values were recorded in the instrument storage area.

Results: Average temperature was 21.3°C (SD 1.2°C; range 18.9°C-27.2°C) and average humidity was 51.7% (SD 3.9%; range 39%- 70%). Groups 1 (time-zero control) and 2 (sterile cellulose wrapping) demonstrated no growth. After 6 and 12 weeks, groups 3 (sterile peel packaging) and 4 (control) demonstrated bacterial growth.

Conclusion: The most common culture isolates were gram-positive rods and two common nosocomial Staphylococcius species. Sterile peel packaging was not found to be equivalent to sterile cellulose wrapping in austere environmental conditions.

Background: The Tactical Pneumatic Tournqiuet 2" (TPT2, 5.1cm-wide deflated) allows total average applied pressure measurement, which should be useful toward development of emergency-use limb tourniquet certification devices.

Methods: The TPT2 hand bulb was replaced with stopcocks and syringes, allowing filling with continuous pressure measurement. Forearm and mid-thigh applications involved two sets of five Doppler-based pulse gone/return pairs. Second set pulse gones were chosen a priori for occlusion pressures (preliminary work indicated greater consistency in second sets).

Results: All 68 forearms occluded (30 female, 38 male, median circumference 17.8cm, range 14.6-23.5cm; median second set of pulse gone tourniquet pressures 176mmHg, range 128-282mmHg). Fifty-five thighs occluded (median circumference 54.3cm, range 41.6-62.4cm; median systolic pressure 126mmHg, range 102-142mmHg; median second set of pulse gone pressures 574mmHg, range 274-1158mmHg). Thirteen thigh applications were stopped without occlusion because of concerning pressures combined with no indication of imminent occlusion and difficulties forcing more air into the TPT2 (3 female, 10 male, peak pressures from 958-1377mmHg, median 1220mmHg, p<.0001 versus occluded thighs; median circumference 63.3cm, range 55.0-72.9cm, p<.0001 versus occluded thighs; median systolic pressure 126mmHg, range 120-173mmHg, p<.019 versus occluded thighs). Thigh TPT2 impression widths on five subjects after occlusion were as follows: 3.5cm, occlusion 274mmHg; 2.8cm, occlusion 348mmHg; 2.9cm, occlusion 500mmHg; 2.8cm, occlusion 782mmHg; 2.7cm, occlusion 1114mmHg.

Conclusions: Though probably useful to tourniquet certification, the required pressures for thigh occlusion make the TPT2 undesirable for any clinical use, emergency or otherwise.