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17. DCR for Non-trauma Patients
Keywords
Massive transfusionDamage control resuscitationPediatric hemorrhageGeriatric hemorrhageObstetric hemorrhageBlood componentsWhole bloodTranexamic acidFactor VIIaProthrombin complex concentrateIntroduction
Since the introduction of the truncated laparotomy in 1983 [1] and subsequent popularization of damage control surgery (DCS) by Rotondo et al. in 1993 [2], similar concepts have been applied to resuscitation, termed damage control resuscitation (DCR) [3, 4]. DCR combats the “lethal triad” of trauma coagulopathy and has become the standard of care for severely injured trauma victims with exsanguinating hemorrhage [4–8]. When combined with DCS, this approach has been associated with improved patient outcomes [9]. The fundamental importance of hemostatic resuscitation was underscored by the PROPPR trial in which patients in the 1:1:1 group achieved hemostasis sooner and had decreased mortality from hemorrhage within the first 24 hours [10].
Pediatrics
The principles of DCR should be in the forefront of every practitioner’s mind taking care of a bleeding pediatric patient. The core tenets of DCR in this population remain the same: hemostatic resuscitation while limiting crystalloid administration, recognizing and treating causes of hypothermia, coagulopathy and acidosis, and rapid definitive hemostasis [17]. There are, however, multiple unique elements of pediatric morphology and physiology that make DCR in this population particularly challenging. Pediatric patients are thinner, have less subcutaneous fat, and have an increased surface area to body mass ratio and are thus vulnerable to hypothermia [18]. Furthermore, although pediatric patients have relatively more circulating volume (10% body weight vs. 7% in adults), the absolute pediatric blood volume is quite small [19, 20]. Thus, even seemingly small volumes of blood loss can represent a catastrophic hemorrhage in a child. Finally, although pediatric patients have increased cardiac reserve and are able to compensate for up to nearly 50% of blood loss before developing hypotension, once this reserve is spent, they tend to progress quickly to cardiac arrest [21]. Evidence suggests that pediatric patients may also respond differently to inflammation as compared to adults [22] and that children less than 12 months of age have immature hemostatic systems and may have different blood transfusion requirements [23]. Additionally, procoagulant factor levels are reportedly low in pediatric patients until 6 months of age although the functional significance of these differences remains unclear [24]. Similarly, difference in platelet function, aggregation, and adhesion are also described [25].
With these important differences in mind, the following paragraphs summarize our current understanding of the application of adult DCR principles to pediatric patients. Historically, DCR has been used in pediatric patients undergoing burn resection and reconstruction for craniosynostosis [26]. More recently, data from combat operations in Iraq and Afghanistan have shed more light on the application of DCR in injured children [27, 28] while the ongoing MAssive Transfusion In Children (MATIC) study promises to illuminate modern pediatric resuscitation in civilian practice for both trauma and non-trauma patients (http://pediatrics.wustl.edu/matic/AboutMATIC).
Permissive Hypotension
Minimize Crystalloids
There is evidence , however, to support the deleterious effects of crystalloid infusions in pediatric patients. Prehospital IV fluid administration has been associated with increased transfusion requirements, abnormal laboratory coagulation parameters, as well as a trend toward increased mortality [35]. In a recent large study of over 1300 pediatric trauma patients in Iraq and Afghanistan, investigators identified an association between crystalloid volume and both increased length of stay and prolonged ventilator days [36].
Coagulopathy and Shock
There is general consensus that the acute coagulopathy of trauma present in adults is also present in pediatric trauma patients. In a recent retrospective review of over 800 pediatric patients, early coagulopathy was present approximately one-third of patients and was associated with a significant increase in mortality [37]. Similar results have been reported in pediatric patients treated during combat operations [38]. Not surprisingly, hypotension and injury severity score with associated with early coagulopathy in pediatric patients [37].
Transfusion
Similar to adult patient populations, a massive transfusion protocol (MTP) should be implemented in all pediatric tertiary care centers [18, 21]. In pediatric patients, massive transfusion is defined as one of the following: transfusion >100% of estimated blood volume in 24 hours, ongoing transfusion of >10% of blood volume per minute, or replacement of 50% of estimated blood volume in 3 hours or less [23]. Importantly, a threshold of 40 cc/kg of all blood product transfused during the first 24 hours identified children at risk for mortality [27].
Although the evidence for MTP use in pediatric patients is still emerging, developing and employing an MTP for bleeding pediatric patients are likely beneficial [24]. The optimal target ratios of packed red blood cells, plasma, and platelets for the empiric phase of an MTP have yet to be firmly defined. It seems, however, that in pediatric patients, there may be more latitude in the exact ratio than in adults [28, 39]. Likewise, the optimal order of blood product administration has yet to be precisely defined. So long as volume overload is avoided, it is likely safe to lead with plasma and platelets followed by red blood cells. In the absence of an established best practice, there remains a lot of variation in the implementation of pediatric MTPs [23]. Fortunately, MTP for trauma in pediatric patients remains a relatively uncommon event compared to adults [40]. There is some evidence to support the use of TXA in pediatric trauma [41]; however, a recent survey of pediatric hospitals found that only 15% use antifibrinolytic therapy routinely [42].
Geriatrics/Elderly
Elderly patients represent an ever-growing demographic in our society. Although the elderly represents one-eighth of the population, they consume one quarter of trauma and critical care expenditures [43]. Patients over the age of 65 undergo approximately two million operations annually [44]. Studies have shown worse outcomes for elderly patients undergoing emergency operations [45] and when compared with their younger peers, elderly trauma patients are characterized as having worse outcomes [46]. Likewise, for those patients aged 65–79 undergoing a massive transfusion (defined as ≥10 units packed red blood cells over 2 consecutive calendar days [as an approximation for 24 hours given the nature of the data collection format for the registry]) for any indication, 30-day mortality was 27.7% and for patients over the age of 80 was 36%, compared to a mortality of just over 10% in patients ages 18–39 in a recent epidemiologic analysis [15]. This association between massive transfusion, age and mortality was also confirmed by another recent study [14]. Thus, we believe there are some important considerations when applying DCR principles to this population although to date, no study has specifically evaluated DCR outcomes in the elderly [47].
Neurologic |
Decreased brain mass |
Impaired autoregulation |
Cardiovascular |
Decreased maximum HR |
Decreased maximum CO |
Large arteries decreased compliance |
Increased peripheral vascular resistance |
Increased systolic blood pressure |
Pulmonary |
Decreased FEV1 and FVC |
Increased VQ mismatch |
Decreased inspiratory and expiratory pressures |
Decreased alveolar surface area |
Renal |
Decreased solute secretion |
Decreased renal mass |
Decreased response to ADH, renin, and aldosterone |
Temperature regulation |
Decreased shivering |
Decreased vasoconstriction |
Decreased sweat production |
Permissive Hypotension
Because vital signs are not a useful indicator of hypoperfusion in the elderly, the practice of permissive hypotension in this population is controversial. Permissive hypotension in the elderly has been studied in a retrospective fashion and was not associated with increased survival [59, 60]. However, the quality of the evidence is low and randomized controlled trials are lacking.
Crystalloids
Like in adults and pediatrics, however, the evidence supporting limiting crystalloid infusions in geriatric patients is more robust. In elderly patients in hemorrhagic shock, attempts should be made to limit crystalloid to two liters during the emergency department phase of patient care [61, 62].
Transfusions
Elderly patients have different cardiac physiology including impaired ventricular filling, decreased maximal cardiac output, and a decreased maximal heart rate [63]. Additionally, geriatric patients have a smaller blood volume and blunted cardiovascular responses [64]. Some studies also support more aggressive transfusion thresholds in non-bleeding geriatric patient with myocardial infarction [63]. Whether or not these benefits extended to patients undergoing DCR remains unclear.
Other non-trauma indications for DCR in the elderly patient population includes aortic surgery, cardiac surgery, and gastrointestinal hemorrhage. Recent studies have attempted to mitigate bleeding risk and the need for transfusion in these patient populations. For example, a recent randomized controlled trial of elderly patients undergoing combined coronary artery bypass grafting and aortic valve surgery found that prophylactic tranexamic acid reduced blood transfusion requirements perioperatively [65].
Anticoagulant and antiplatelet therapy in the aging population is also an important consideration during DCR of the elderly patient. These medications are widely prescribed and carry a substantial bleeding risk [50]. Particularly, the use of these medications increases the risk of intracranial hemorrhage. Additionally, these patients are also at risk for delayed hemorrhage following a negative CT scan examination of the head. Studies have shown that anticoagulant use increases the risk of mortality by sixfold in patients with a traumatic brain injury [66]. Although it is beyond the scope of this chapter, prompt reversal of therapeutic anticoagulation should be part of DCR for bleeding -injured and non-injured patients alike.
Obstetrics
Despite common perception, in large epidemiologic studies in industrialized nations, massive transfusion due to obstetrical bleeding is low 1.8% [15], and obstetrics patients have the lowest mortality following MTP (2.8%) [14]. When maternal bleeding does occur, however, it can be very dramatic and acute care surgeons are likely to be consulted to aid in the multidisciplinary care of these patients [67].
Plasma volume | Increases |
Red blood cell mass | Increases |
White blood cell count | Increases |
Peripheral vascular resistance | Decreases |
Heart rate | Increases |
Systolic blood pressure | Decreases |
Cardiac output | Increases |
Clotting factors | Increase |
Respiratory rate | Increases |
Glomerular filtration rate | Increases |