Dobson GP, Letson HL 20(3). 128 - 134 (Journal Article)
Future expeditionary missions are expected to occur in more remote austere environments where combat medics and casualties may have to wait up to 7 days before resupply or safe evacuation. Currently, there is no effective fluid therapy for hemorrhagic shock (HS) at the point-of-injury and continuum-of-care over this extended period. We have been developing a small-volume IV or IO ALM therapy for noncompressible HS and have shown in preclinical models that it extends survival to 3 days, reduces abdominal bleeding by 60%, blunts inflammation, corrects coagulopathy, preserves platelet function, and prevents immunodeficiency. The ALM-survival phenotype is associated with an upregulation of the master genes of metabolism and mitochrondrial biogenesis in heart and brain and a downregulation in the periphery. Future translational studies will investigate the timing and nature of the "switch" and extend survival to 7 days. We will also discuss some of the controversies of ALM resuscitation in pigs, present our Systems Hypothesis of Trauma (SHOT), and discuss future clinical safety trials before field use.
Staak BP, Petersen CD, Smith J, Hartman M, Rush SC 20(3). 135 - 140 (Journal Article)
Best practices and training for prolonged field care (PFC) are evolving. The New York Pararescue Team has used part task training, cadaver labs, clinical rotations, and a complicated sim lab to prepare for PFC missions including critical care. This report details an Atlantic Ocean nighttime parachute insertion to provide advanced burn care to two sailors with 50% and 60% body surface area burns. Medical mission planning included pack-out of ventilators, video laryngoscopes, medications, and 50 L of lactated Ringer's (LR). Over the course of 37 hours, the patients required high-volume resuscitation, analgesia, wound care, escharotomies, advanced airway and ventilator management, continuous sedation, telemedicine consultation, and complicated patient movement during evacuation. A debrief survey was obtained from the Operators highlighting recommendation for more clinical rotations and labs, missionspecific pack-outs, and tactical adjustments. This historic mission represents the most sophisticated PFC ever performed by PJs and serves to validate and share our approach to PFC.
Hall AB, Morrow L, Dixon M 20(3). 120 - 121 (Journal Article)
This case describes the prolonged treatment of a 38-year-old man with a transpelvic gunshot wound requiring a diverting ostomy and cystostomy for damage control procedures with a comminuted acetabular and femoral head fracture. The team used a ketamine drip for prolonged field care over 48 hours. The benefit of using a ketamine drip included low supply requirement, excellent analgesia, and ease of administration, but side-effects included somnolence and atelectasis necessitating oxygen supplementation before evacuation.
Mix JW, DeSoucy ES, Hilser A, Houser DJ, Mhayamaguru KM, Dorsch J, Gaither JB, Rush SC 20(3). 122 - 127 (Journal Article)
Background: US Air Force (USAF) pararescuemen (PJs) perform long-range ocean rescue missions for ill or injured civilians when advanced care and transport are not available. The purpose of this case series is to examine the details of these missions, review patient treatments and outcomes, and describe common tactics, techniques, and procedures for these missions. Methods: Cases in which the USAF PJs preformed long-range ocean rescue for critically ill or injured civilians between 2011 and 2018 were identified. Case information was obtained, including patient demographics, location, infiltration/exfiltration methods, diagnoses, treatments, duration of patient care, patient outcome, and lessons learned. Results: A total of 14 pararescue missions involving 22 civilians were identified for analysis. Of the 22 patients, 10 (45%) suffered burns, six (27%) had abdominal issues, four (18%) had musculoskeletal injuries, one had a traumatic brain injury, and one had a necrotizing soft-tissue infection. Medical care of these patients included intravenous fluid and blood product resuscitation, antibiotics, analgesics, airway management, and escharotomy. The median duration of patient care was 51 hours. Conclusion: This case series illustrates the complex transportation requirements, patient and gear logistical challenges, austere medicine, and prolonged field care (PFC) unique to USAF PJ open-water response.
Alexander DW 20(3). 109 - 112 (Journal Article)
The SOCOM Spiritual Fitness Scale (SSFS) enables religious support teams and other spiritual fitness/performance (SF/SP) stakeholders in the Special Operations Forces community to reliably measure both "horizontal" and "vertical" dimensions of spirituality, as defined by the chairman of the Joint Chiefs of Staff Instruction on SF. The SSFS's three subscales relate to core attributes of SF/SP, which were identified through factor analysis during the iterations of the tool's development. The SSFS is capable of generating baseline assessments for research related to SF/SP. It is also capable of generating unique SF/SP profiles for individuals and groups, which can shape programs and inform tailored coaching for optimized performance.
Knapik JJ, Hoedebecke BL, Mitchener TA 20(3). 114 - 116 (Journal Article)
This is second of a two-part series on the history and effectiveness of mouthguards (MGs) for protection from orofacial injuries. MGs are hypothesized to reduce orofacial injuries by separating the upper and lower dentation, preventing tooth fractures, redistributing and absorbing the force of direct blows to the mouth, and separating teeth from soft tissue which helps prevent lacerations and bruises. The single study on MG use in military training found that when boil-and-bite MGs were required for four training activities, orofacial injury rates were reduced 56% compared with when MGs were required for just one training activity. A recent systematic review on the effectiveness of MGs for prevention of orofacial injuries included 23 studies involving MG users and nonusers and a wide variety of sports. For cohort studies that directly collected injury data, the risk of an orofacial injury was 2.33 times higher among MG nonusers (95% confidence interval, 1.59-3.44). More well-designed studies are needed on the effectiveness of MGs during military training. Despite some methodological limitations, the current data suggest that MGs can substantially reduce the risk of orofacial injuries in sport activities. MGs should be used in activities where there is a significant risk of orofacial injuries.
Kroshus E, Cameron KL, Coatsworth JD, D'Lauro C, Kim NJ, Lee KM, Register-Mihalik J, Milroy JJ, Roetert EP, Schmidt JD, Silvermann RD, Warmath D, Wayment HA, Hainline B 20(3). 88 - 95 (Journal Article)
Early disclosure of possible concussive symptoms has the potential to improve concussion-related clinical outcomes. The objective of the present consensus process was to provide useful and feasible recommendations for collegiate athletic departments and military service academy leaders about how to increase concussion symptom disclosure in their setting. Consensus was obtained using a modified Delphi process. Participants in the consensus process were grant awardees from the National Collegiate Athletic Association and Department of Defense Mind Matters Research & Education Grand Challenge and a multidisciplinary group of stakeholders from collegiate athletics and military service academies. The process included a combination of in-person meetings and anonymous online voting on iteratively modified recommendations for approaches to improve concussion symptom disclosure. Recommendations were rated in terms of their utility and feasibility in collegiate athletic and MSA settings with a priori thresholds for retaining, discarding, and revising statements. A total of 17 recommendations met thresholds for utility and feasibility and are grouped for discussion in five domains: (1) content of concussion education for athletes and MSA cadets, (2) dissemination and implementation of concussion education for athletes and military service academy cadets, (3) other stakeholder concussion education, (4) team and unit-level processes, and (5) organizational processes. Collectively, these recommendations provide a path forward for athletics departments and military service academies in terms of the behavioral health supports and institutional processes that are needed to increase early and honest disclosure of concussion symptoms and ultimately to improve clinical care outcomes.
Gray BO, St. George D, Cativo M, Tagore A, Ariyaprakai N, Palmer LE 20(3). 103 - 108 (Journal Article)
Severe acute respiratory syndrome coronavirus 2 (SARSCov- 2) is hypothesized to have originated from a spillover event from an animal reservoir. This has raised many questions, with an important one being whether the widely disseminated coronavirus disease 2019 (COVID-19) is transmissible to other animal species. SARS-CoV-2 is primarily transmitted person to person. K9-to-human transmission, although theoretically possible via fomites, is considered minimal, if at all, and there have been no reported cases of K9-to-human transmission. Human-to-K9 transmission, although rare, seems more likely; however, in only one case has a K9 been suspected to have displayed symptoms of COVID-19. Preparation, decontamination, hand hygiene, and distancing remain the key factors in reducing transmission of the virus. The information presented is applicable to personnel operating within the military conventional and Special Operation Forces as well as civilian Tactical Emergency Medical Services communities who may have the responsibility of supporting an operational K9.
Schauer SG, Naylor JF, Ahmed YM, Maddry JK, April MD 20(3). 76 - 80 (Journal Article)
Background: The United States (US) military utilizes combat wound medication packs (CWMP) to provide analgesia and wound prophylaxis in casualties who are still able to fight. We compared characteristics of combat casualties receiving CWMP to those not receiving CWMP. We also describe the proportions of casualties with injury patterns consistent with Tactical Combat Casualty Care (TCCC) guideline indications for CWMP use who received this intervention. Methods: This is a secondary analysis of Department of a Defense Trauma Registry (DODTR) dataset of US military personnel from January 2007 to August 2016. We searched for all subjects with documented use of at least one medication from the CWMP (acetaminophen, meloxicam, moxifloxacin). Results: Within our dataset, 11,665 casualties were US military Servicemembers. Overall, <1% (84) of our study population received the CWMP. The median age and mechanism of injuries were similar between CWMP nonrecipients versus recipients. Median composite injury scores were higher for nonrecipients than recipients (6 versus 4, P < .001). Proportions of casualties with injury patterns meeting TCCC guideline CWMP indications who received this intervention were low: gunshot wound, <1% (14 of 1805), tourniquet applied, <1% (11 of 1912), major amputation, <1% (5 of 803), and open fracture, <1% (10 of 2425). Based on serious injuries by body region, we had similar findings for the thorax (<1%; 3 of 1122), abdomen (<1%; 1 of 736), and extremities (<1%; 11 of 2699). Conclusions: Subjects receiving the CWMP were less severely injured compared to those who did not receive this intervention. The CWMP had very infrequent use among those casualties with injury patterns meeting indications specified in the TCCC Guidelines for use of this intervention.
Fisher AD, Schwartz DS, Petersen CD, Meyer SE, Thielemann JN, Redman TT, Rush SC 20(3). 81 - 86 (Journal Article)
Background: Opioids can have adverse effects on casualties in hemorrhagic shock. In 2014, the Committee on Tactical Combat Casualty Care (CoTCCC) recommended the use of ketamine at the point of injury (POI). Despite these recommendations the adherence is moderate at best. Poor use may stem from a lack of access to use ketamine during training. The United States Special Operations Command (USSOCOM) is often in a unique position, they maintain narcotics for use during all training events and operations. The goal of this work is to demonstrate that ketamine is safe and effective in both training and operational environments. Methods: This was a retrospective, observational performance improvement project within United States Special Operations Command and Air Combat Command that included the US Army's 75th Ranger Regiment, 160th Special Operations Aviation Regiment, and US Air Force Pararescue. Descriptive statistics were used to calculate the doses per administration to include the interquartile range (IQR), standard deviation (SD) and the range of likely doses using a 95% confidence interval (CI). A Wilcoxon signed-rank test was used to compare the mean pre-ketamine pain scores to the mean post-ketamine on a 0-to-10 pain scale. Results: From July 2010 to October 2017, there was a total of 34 patients; all were male. A total of 22 (64.7%) received intravenous ketamine and 12 (35.3%) received intramuscular ketamine and 8 (23.5%) received intranasal ketamine. The mean number of ketamine doses via all routes administered to patients was 1.88 (SD 1.094) and the mean total dose of all ketamine administration was 90.29mg (95% CI, 70.09-110.49). The mean initial dose of all ketamine administration was 47.35mg (95% CI, 38.52-56.18). The median preketamine pain scale for casualties was noted to be 8.0 (IQR 3) and the median post-ketamine pain scale was 0.0 (IQR 3). Conclusion: Ketamine appears to be safe and effective for use during military training accidents. Military units should consider allowing their medics to carry and use as needed.
Shukal A, Perez C, Hoemann B, Keasal M 20(3). 67 - 70 (Journal Article)
Over the course of nearly 19 years of conflict, Tactical Combat Casualty Care (TCCC) guidelines and their implementation have evolved to incorporate the latest advances in trauma research, casualty care, and transport, playing a large role in generating the lowest incidence of preventable deaths in the history of modern warfare. During the conflicts in Afghanistan and Iraq, the adoption and implementation of TCCC principles by conventional forces have been extrapolated to have been responsible for saving the lives of more than 1,000 US Servicemembers. As the intensity and nature of the military conflicts in Afghanistan and Iraq change, and a growing potential for a near peer conflict rises, it remains important that the lessons of TCCC continue to be instilled in our formations in garrison, before deployment, and while in theater. This article reviews the use of TCCC principles by an assault helicopter battalion, in combination with a variety of other factors, in the successful management of a mass casualty event during Operation Freedom's Sentinel 2019 in Afghanistan.
Meadows RM, Monti JD, Umar MA, Van Arnem KA, Chin EJ, Mitchell CA, Love S 20(3). 71 - 75 (Journal Article)
Background: Ultrasound, due to recent advances in portability and versatility, has become a valuable clinical adjunct in austere, resource-limited settings and is well demonstrated to be an accurate/efficient means to detect pneumothorax. The purpose of this study was to evaluate the impact of hands-on ultrasound training on ultrasound-naive US Army combat medics' ability to detect sonographic findings of pneumothorax with portable ultrasound in a cadaver model. Methods: Ultrasound-naive US Army combat medics assigned to conventional military units were recruited from a single US Army installation and randomized to receive either didactic training only, or "blended" (didactic and hands-on) training on ultrasound detection of pneumothorax. Blinded participants were asked to perform a thoracic ultrasound exam on ventilated human cadaver models. Primary outcome measured was sensitivity and specificity of detecting sonographic findings of pneumothorax between cohorts. Results: Forty-three participants examined a total of 258 hemithoraces. The didactic-only cohort (n = 24) detected sonographic findings of pneumothorax with a sensitivity of 68% and specificity of 57%. The blended cohort (n = 19) detected sonographic findings of pneumothorax with an overall sensitivity of 91% and specificity of 80%. Detection sensitivities were similar between B-mode versus M-mode use. Conclusion: US Army combat medics can use portable U/S to detect sonographic findings of pneumothorax in a human cadaver model with high sensitivity after a brief, blended (didactic and hands-on) training intervention.
Hingtgen E, Wall PL, Buising CM 20(3). 52 - 61 (Journal Article)
Background: The OMNA Marine Tourniquet is a 5.1cm-wide, simple redirect buckle, hoop-and-loop secured, ratcheting tourniquet designed for storage and use in marine environments. This study evaluated self-application effectiveness and pressures. Methods: Triplicate secured, occlusion, and completion pressures were measured during 60 subjects pulling down or up thigh applications and nondominant, single-handed arm applications. Arm pressure measurements required circumferences ≥30cm. Results: Thirty-one subjects had arm circumferences ≥30cm. All 540 applications were effective; 376 of 453 applications had known secured pressures >150mmHg (89 of 93 arm). Thigh down versus up pulling directions were not different (secured, occlusion, and completion pressures and ladder tooth advances). Occlusion pressures were 348mmHg (275-521mmHg) for combined thighs and 285mmHg (211-372mmHg) for arms. Completion pressures were 414mmHg (320-588mmHg) for combined thighs and 344mmHg (261-404mmHg) for arms. Correlations between secured pressures and occlusion ladder tooth advances (clicks) were r2 = 0.44 for combined thighs and 0.68 for arms. Correlations between occlusion pressures and occlusion clicks were poor (r2 = 0.24, P < .0001 for combined thighs and r2 = 0.027, P = .38 for arms). Conclusions: The OMNA Marine Tourniquet can be self-applied effectively, including one-handed applications. Occlusion and completion pressures are similar to reported 3.8cm-wide Ratcheting Medical Tourniquet pressures.
Schauer SG, April MD, Tanaka K, Baldwin D, Maddry JK, Becker TE, De Lorenzo RA 20(3). 62 - 66 (Journal Article)
Introduction: Airway compromise is the second leading cause of potentially survivable death on the battlefield. Studies show that airway management is a challenge in prehospital combat care with high error and missed opportunity rates. Lacking is user information on the perceived reasons for the challenges. The US military uses several performance improvement and field feedback systems to solicit feedback regarding deployed experiences. We seek to review feedback and after-action reviews (AARs) from end-users with specific regard to airway challenges noted. Methods: We queried the Center for Army Lessons Learned (CALL), the Army Medical Department Lessons Learned (AMEDDLL), and the Joint Lessons Learned Information System (JLLIS).Our queries comprised a series of search terms with a focus on airway management. Three military emergency medicine expert reviewers performed the primary analysis for lessons learned specific to deployment and predeployment training lessons learned. Upon narrowing the scope of entries to those relevant to deployment and predeployment training, a panel of eight experts performed reviews. The varied nature of the sources lent itself to an unstructured qualitative approach with results tabulated into thematic categories. Results: Our initial search yielded 611 nonduplicate entries. The primary reviewers then analyzed these entries to determine relevance to the project-this resulted in 70 deployment- based lessons learned and four training-based lessons learned. The panel of eight experts then reviewed the 74 lessons learned. We categorized 37 AARs as equipment challenges/malfunctions, 28 as training/education challenges, and 9 as other. Several lessons learned specifically stated that units failed to prioritize medic training; multiple comments suggested that units should consider sending their medics to civilian training centers. Other comments highlighted equipment shortages and equipment malfunctions specific to certain mission types (e.g., pediatric casualties, extreme weather). Conclusions: In this review of military lessons learned systems, most of the feedback referenced equipment malfunctions and gaps in initial and maintenance training.This review of AARs provides guidance for targeted research efforts based the needs of the end-users.
Drew B, Auten JD, Cap AP, Deaton TG, Donham B, Dorlac WC, DuBose JJ, Fisher AD, Ginn AJ, Hancock J, Holcomb JB, Knight J, Koerner AK, Littlejohn LF, Martin MJ, Morey JK, Morrison J, Schreiber MA, Spinella PC, Walrath B, Butler FK 20(3). 36 - 43 (Journal Article)
The literature continues to provide strong support for the early use of tranexamic acid (TXA) in severely injured trauma patients. Questions persist, however, regarding the optimal medical and tactical/logistical use, timing, and dose of this medication, both from the published TXA literature and from the TCCC user community. The use of TXA has been explored outside of trauma, new dosing strategies have been pursued, and expansion of retrospective use data has grown as well. These questions emphasize the need for a reexamination of TXA by the CoTCCC. The most significant updates to the TCCC Guidelines are (i) including significant traumatic brain injury (TBI) as an indication for TXA, (ii) changing the dosing protocol to a single 2g IV/IO administration, and (iii) recommending TXA administration via slow IV/IO push.
Kragh JF, Aden JK, Dubick MA 20(3). 44 - 51 (Journal Article)
Background: Given little data to assess guidelines, we sought a way to exchange one type of intervention, field tourniquet use, for another, use of a pressure dressing. The study purpose was to test performance of controlling simulated bleeding with a stepwise procedure of tourniquet conversion. Methods: An experiment was designed to assess 15 tests of a caregiver making tourniquet-dressing conversions. Tests were divided into trials: tourniquet use and its conversion. In laboratory conditions, the tourniquet trial was care under gunfire; then, the conversion trial was emergency healthcare. A HapMed Leg Tourniquet Trainer simulated a limb amputation. An investigator provided healthcare. Results: Mean (± standard deviation [SD]) test time and blood loss were 9 ± 3.6 minutes and 334 ± 353.9mL, respectively. The first test took 17 minutes. By test number, times decreased; the last six took ≤7 minutes. All tourniquet trials controlled bleeding. Mean (±SD) tourniquet pressure and blood loss were 222 ± 18.0mmHg and 146 ± 40.9mL, respectively. Bleeding remained uncontrolled in one conversion. Initial attempts to wrap a dressing were effective in 73% of tries (n = 11 of 15). Four of 15 wrap attempts (27%) were repeated to troubleshoot bleeding recurrence, and the first three tests required a repetition. Mean (±SD) dressing pressures and blood losses were 141 ± 17.6mmHg and 188 ± 327.4mL, respectively. Unsatisfactory conversion trials had a dressing pressure <137mmHg. Dressings and wraps hid the wound to impair assessment of bleeding. Conclusions: In testing a method of converting a limb tourniquet to a pressure dressing, the caregiver performed faster with experience accrual. The tourniquet results were uniformly good, but conversion results were worse and more varied. Simulating conversion was disappointing on a manikin and indicated that its redesign might be needed to suit this method. The procedural method constituted a start for further development.
Nicholson J, Searor JN, Lane AD 20(3). 117 - 119 (Editorial)
America's adversaries will contest US military superiority in the domains of land, sea, air, space, and cyberspace. Fundamentally, these foes seek to disrupt the dominance of American fighting forces through anti-access and area denial (A2AD) systems, such as cyber exploitation, electromagnetic jamming, air defense networks, and hypersonic capabilities. According to Training and Doctrine Command (TRADOC) Pamphlet 525- 3-1, these A2AD capabilities create multiple layers of stand-off that inhibit the US ability to focus combat power and achieve strategic objectives in a contested, increasingly lethal, inherently complex, and challenging operational environment.1 The Department of Defense (DoD) plans to mitigate this shift in enemy strategy through the adoption of multidomain operations (MDO).1 MDO is defined as operations that converge capabilities to overcome an adversary's strengths across various domains by imposing simultaneous dilemmas that achieve operational and tactical objectives.1 Within this MDO construct, medical treatment expectations must shift accordingly as the ability to rapidly treat and evacuate patients may be constrained by enemy action. Thus, the notion of prolonged field care (PFC) may be a necessity on the future battlefield. As Special Operations Forces (SOF) continue to refine what PFC entails, it is imperative that an understanding of the incidence and type of diseases that require medical evacuation to higher levels of care be thoughtfully estimated. Armed with an understanding of the anticipated epidemiology, effective prioritization of training requirements and equipment acquisition is possible in a manner that is complementary to the overall success of the assigned mission. Furthermore, this prior planning mitigates risk, as the limitations of money and time impose significant opportunity costs in the short run should the disproportionate mix of disease states be pursued, which in turn, avoids jeopardizing Soldiers' lives over the long term.
Bennett BL, Giesbrect G, Zafren K, Christensen R, Littlejohn LF, Drew B, Cap AP, Miles EA, Butler FK, Holcomb JB, Shackelford SA 20(3). 21 - 35 (Journal Article)
As an outcome of combat injury and hemorrhagic shock, trauma-induced hypothermia (TIH) and the associated coagulopathy and acidosis result in significantly increased risk for death. In an effort to manage TIH, the Hypothermia Prevention and Management Kit™ (HPMK) was implemented in 2006 for battlefield casualties. Recent feedback from operational forces indicates that limitations exist in the HPMK to maintain thermal balance in cold environments, due to the lack of insulation. Consequently, based on lessons learned, some US Special Operations Forces are now upgrading the HPMK after short-term use (60 minutes) by adding insulation around the casualty during training in cold environments. Furthermore, new research indicates that the current HPMK, although better than no hypothermia protection, was ranked last in objective and subjective measures in volunteers when compared with commercial and user-assembled external warming enclosure systems. On the basis of these observations and research findings, the Committee on Tactical Combat Casualty Care decided to review the hypothermia prevention and management guidelines in 2018 and to update them on the basis of these facts and that no update has occurred in 14 years. Recommendations are made for minimal costs, low cube and weight solutions to create an insulated HPMK, or when the HPMK is not readily available, to create an improvised hypothermia (insulated) enclosure system.
Hoggarth A, Grist M, Murch T 20(2). 154 - 155 (Journal Article)
Thompson P, Hudson AJ, Convertino VA, Bjerkvig C, Eliassen HS, Eastridge BJ, Irvine-Smith T, Braverman MA, Hellander S, Jenkins DH, Rappold JF, Gurney JM, Glassberg E, Cap AP, Aussett S, Apelseth TO, Williams S, Ward KR, Shackelford SA, Stroberg P, Vikeness BH, Pepe PE, Winckler CJ, Woolley T, Enbuske S, De Pasquale M, Boffard KD, Austlid I, Fosse TK, Asbjornsen H, Spinella PC, Strandenes G 20(3). 97 - 102 (Editorial)
Based on limited published evidence, physiological principles, clinical experience, and expertise, the author group has developed a consensus statement on the potential for iatrogenic harm with rapid sequence induction (RSI) intubation and positive-pressure ventilation (PPV) on patients in hemorrhagic shock. "In hemorrhagic shock, or any low flow (central hypovolemic) state, it should be noted that RSI and PPV are likely to cause iatrogenic harm by decreasing cardiac output." The use of RSI and PPV leads to an increased burden of shock due to a decreased cardiac output (CO)2 which is one of the primary determinants of oxygen delivery (DO2). The diminishing DO2 creates a state of systemic hypoxia, the severity of which will determine the magnitude of the shock (shock dose) and a growing deficit of oxygen, referred to as oxygen debt. Rapid accumulation of critical levels of oxygen debt results in coagulopathy and organ dysfunction and failure. Spontaneous respiration induced negative intrathoracic pressure (ITP) provides the pressure differential driving venous return. PPV subsequently increases ITP and thus right atrial pressure. The loss in pressure differential directly decreases CO and DO2 with a resultant increase in systemic hypoxia. If RSI and PPV are deemed necessary, prior or parallel resuscitation with blood products is required to mitigate post intervention reduction of DO2 and the potential for inducing cardiac arrest in the critically shocked patient.