The use and timing of angioembolization in pediatric blunt liver and spleen injury.

BACKGROUND: Nonoperative management (NOM) is the standard of care for the management of blunt liver and spleen injuries (BLSI) in the stable pediatric patient. Angiography with embolization (AE) is used as an adjunctive therapy in the management of adult BLSI patients, but it is rarely used in the pediatric population. In this planned secondary analysis, we describe the current utilization patterns of AE in the management of pediatric BLSI. METHODS: After obtaining IRB approval at each center, cohort data was collected prospectively for children admitted with BLSI confirmed on CT at 10 Level I pediatric trauma centers (PTCs) throughout the United States from April 2013 to January 2016. All patients who underwent angiography with or without embolization for a BLSI were included in this analysis. Data collected included patient demographics, injury details, organ injured and grade of injury, CT finding specifics such as contrast blush, complications, failure of NOM, time to angiography and techniques for embolization. RESULTS: Data were collected for 1004 pediatric patients treated for BLSI over the study period, 30 (3.0%) of which underwent angiography with or without embolization for BLSI. Ten of the patients who underwent angiography for BLSI failed NOM. For patients with embolized splenic injuries, splenic salvage was 100%. Four of the nine patients undergoing embolization of the liver ultimately required an operative intervention, but only one patient required hepatorrhaphy and no patient required hepatectomy after AE. Few angiography studies were obtained early during hospitalization for BLSI, with only one patient undergoing angiography within 1 hour of arrival at the PTC, and 7 within 3 hours. CONCLUSION: Angioembolization is rarely used in the management of BLSI in pediatric trauma patients with blunt abdominal trauma and is generally used in a delayed fashion. However, when implemented, angioembolization is associated with 100% splenic salvage for splenic injuries. LEVEL OF EVIDENCE: Therapeutic/Care Management; Level IV.

Hemodilution in pediatric trauma: Defining the expected hemoglobin changes in patients with liver and/or spleen injury: An ATOMAC+ secondary analysis.

BACKGROUND: Many children with blunt liver and/or spleen injury (BLSI) never bleed intraperitoneally. Despite this, decreases in hemoglobin are common. This study examines initial and follow up measured hemoglobin values for children with BLSI with and without evidence of intra-abdominal bleeding. METHODS: Children ≤18 years of age with BLSI between April 2013 and January 2016 were identified from the prospective ATOMAC+ cohort. Initial and follow up hemoglobin levels were analyzed for 4 groups with BLSI: (1) Non bleeding; (2) Bleeding, non transfused (3) Bleeding, transfused, and (4) Bleeding resulting in non operative management (NOM) failure. RESULTS: Of 1007 patients enrolled, 767 were included in one or more of four study cohorts. Of 131 non bleeding patients, the mean decrease in hemoglobin was 0.83 g/dL (+/-1.35) after a median of 6.3 [5.1,7.0] hours, (p = 0.001). Follow-up hemoglobin levels in patients with and without successful NOM were not different. For patients with an initial hemoglobin >9.25 g/dL, the odds ratio (OR) for NOM failure was 14.2 times less, while the OR for transfusion was 11.4 times less (p = 0.001). CONCLUSION: Decreases in hemoglobin are expected after trauma, even if not bleeding. A hemoglobin decrease of 2.15 g/dL [0.8 + 1.35] would still be within one standard deviation of a non bleeding patient. An initial low hemoglobin correlates with failure of NOM as well as transfusion, thereby providing useful information. By contrast, subsequent hemoglobin levels do not appear to guide the need for transfusion, nor correlate with failure of NOM. These results support initial hemoglobin measurement but suggest a lack of utility for routine rechecking of hemoglobin. LEVEL OF EVIDENCE: Level II Prognostic Study.

Racial/ethnic differences in receipt of surgery among children in the United States.

BACKGROUND: It is unknown whether racial/ethnic disparities exist in surgical utilization for children. The aim, therefore, was to evaluate the odds of surgery among children in the US by race/ethnicity to test the hypothesis that minority children have less surgery. METHODS: Cross-sectional data were analyzed on children 0-18 years old from the 1999 to 2018 National Health Interview Survey, a large, nationally representative survey. The primary outcome was odds of surgery in the prior 12 months for non Latino African-American, Asian, and Latino children, compared with non Latino White children, after adjustment for relevant covariates. The National Surgical Quality Improvement Program Pediatric Dataset was used to analyze the odds of emergent/urgent surgery by race/ethnicity. RESULTS: Data for 219,098 children were analyzed, of whom 10,644 (4.9%) received surgery. After adjustment for relevant covariates, African-American (AOR, 0.54; 95% CI, 0.50-0.59), Asian (AOR, 0.39; 95% CI, 0.33-0.46), and Latino (AOR, 0.62; 95% CI, 0.57-0.67) children had lower odds of surgery than White children. Latino children were more likely to require emergent or urgent surgery (AOR, 1.71; 95% CI, 1.68-1.74). CONCLUSIONS: Latino, African-American, and Asian children have significantly lower adjusted odds of having surgery than White children in America, and Latino children were more likely to have emergent or urgent surgery. These racial/ethnic differences in surgery may reflect disparities in healthcare access which should be addressed through further research, ongoing monitoring, targeted interventions, and quality-improvement efforts. LEVEL OF EVIDENCE: II. TYPE OF STUDY: Prognosis study.

Impact of Cryoablation on Pectus Excavatum Repair in Pediatric Patients.

BACKGROUND: Minimally invasive repair of pectus excavatum (MIRPE) involves placement of a transthoracic, retrosternal support bar under thoracoscopic guidance. Despite its minimally invasive technical approach, postoperative pain is a significant morbidity that often results in increased length of stay. Multi-modal pain control strategies have been used in the past with limited success. Recently, the use of intraoperative intercostal nerve cryoablation (CA) has been added. In the present study, we aim to evaluate the effects of CA on postoperative pain control, opioid requirements, and perioperative outcomes. STUDY DESIGN: A single-center, retrospective chart review of all patients (less than 18 years old) who underwent MIRPE from 2009 to 2020 was performed. CA was started in June 2018. Data collection included demographics, preoperative characteristics, intraoperative findings, and postoperative outcomes. We hypothesized that CA would be associated with improved pain scores, lower doses of total inpatient opioid requirement, and shorter length of stay (LOS). RESULTS: One hundred sixty-one patients met inclusion criteria: 75 underwent intraoperative CA and 86 underwent MIRPE without CA (NCA group). CA significantly decreased median LOS from 4 days in NCA to 2 days; the use of CA was the only significant predictor of LOS on linear regression. CA was also associated with decreased total PCA, intravenous opioid, and oral opioid dosages. There was no difference in inpatient pain scores and a slight increase in mean procedure time. However, CA was associated with significantly decreased postoperative complications. CONCLUSIONS: The use of cryoablation during MIRPE significantly decreases LOS, perioperative opioid requirements, and postoperative complications, with a minimal increase in operative time. Cryoablation is an effective pain control modality in the surgical management of chest wall deformities in children.

An unexpected COVID-19 diagnosis during emergency surgery in a neonate.

A 4-day-old, 3.3 kg infant presented with suspected intestinal malrotation, necessitating emergent diagnostic laparoscopy. Intra-operatively, the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) came back positive. This is the first case report of emergency surgery and anesthesia in a positive SARS-CoV-2 newborn. This report highlights a neonate with an incidental positive SARS-CoV-2 test, no known exposure history, negative polymerase chain reaction maternal testing, and absence of respiratory symptoms who required modified pressure control ventilation settings to adequately ventilate with the high-efficiency particulate air filter in situ.

Distilling the Key Elements of Pediatric Appendicitis Clinical Practice Guidelines.

BACKGROUND: Use of clinical practice guidelines (CPGs) have been shown to reduce care delays, optimize resource utilization, and improve patient outcomes. We conducted a systematized review to identify key elements that should be included in an evidence-based CPG for pediatric appendicitis. METHODS: We characterized key decision points and content areas from CPGs developed from 2000 to 2019 that were identified using publicly available platforms and manual search/personal communications. RESULTS: Twenty-seven CPGs were reviewed with content saturation achieved after reviewing eight. We found 16 key elements spanning from triage to postoperative care. Elements with high accord among CPGs included use of laparoscopy and delay of postoperative imaging for abscess screening until postoperative day seven. For simple appendicitis, all CPGs endorsed antibiotic cessation, diet advancement, and early activity, and 11 CPGs included same-day discharge. Elements with heterogeneity in decision-making included antibiotic selection/duration for perforated appendicitis, criteria defining perforation, and utility of postoperative laboratory evaluations. CONCLUSIONS: Development of an evidence-based CPGs for pediatric appendicitis requires attention to a finite number of key decision points and content areas. Existing literature demonstrates improved patient outcomes with CPG implementation.

Early vasopressor administration in pediatric blunt liver and spleen injury: An ATOMAC+ study.

BACKGROUND: No prior studies have examined the outcomes of early vasopressor use in children sustaining blunt liver or spleen injury (BLSI). METHODS: A planned secondary analysis of vasopressor use from a 10-center, prospective study of 1004 children with BLSI. Inverse probability of treatment weighting (IPTW) was used to compare patients given vasopressors <48 h after injury to controls based on pretreatment factors. A logistic regression was utilized to assess survival associated with vasopressor initiation factors on mortality and nonoperative management (NOM) failure. RESULTS: Of 1004 patients with BLSI, 128 patients were hypotensive in the Pediatric Trauma Center Emergency Department (ED); 65 total patients received vasopressors. Hypotension treated with vasopressors was associated with a sevenfold increase in mortality (AOR = 7.6 [p < 0.01]). When excluding patients first given vasopressors for cardiac arrest, the risk of mortality increased to 11-fold (AOR = 11.4 [p = 0.01]). All deaths in patients receiving vasopressors occurred when started within the first 12 h after injury. Vasopressor administration at any time was not associated with NOM failure. CONCLUSION: After propensity matching, early vasopressor use for hypotension in the ED was associated with an increased risk of death, but did not increase the risk of failure of NOM. LEVEL OF EVIDENCE: Level III prognostic and epidemiological, prospective.

Prevalence of pectus excavatum in an adult population-based cohort estimated from radiographic indices of chest wall shape.

BACKGROUND: Pectus excavatum is the most common chest wall skeletal deformity. Although commonly evaluated in adolescence, its prevalence in adults is unknown. METHODS AND FINDINGS: Radiographic indices of chest wall shape were analyzed for participants of the first (n = 2687) and second (n = 1780) phases of the population-based Dallas Heart Study and compared to clinical cases of pectus (n = 297). Thoracic computed tomography imaging studies were examined to calculate the Haller index, a measure of thoracic axial shape, and the Correction index, which quantitates the posterior displacement of the sternum relative to the ribs. At the level of the superior xiphoid, 0.5%, 5% and 0.4% of adult Dallas Heart Study subjects have evidence of pectus excavatum using thresholds of Haller index >3.25, Correction index >10%, or both, respectively. Radiographic measures of pectus are more common in females than males and there is a greater prevalence of pectus in women than men. In the general population, the Haller and Correction indices are associated with height and weight, independent of age, gender, and ethnicity. Repeat imaging of a subset of subjects (n = 992) demonstrated decreases in the mean Haller and Correction indices over seven years, suggesting change to a more circular axial thorax, with less sternal depression, over time. CONCLUSIONS: To our knowledge, this is the first study estimating the prevalence of pectus in an unselected adult population. Despite the higher reported prevalence of pectus cases in adolescent boys, this study demonstrates a higher prevalence of radiographic indices of pectus in adult females.

Physician-Estimated Depth as a Screening Tool for Computed Tomography Evaluation of Pectus Excavatum.

BACKGROUND: Pectus excavatum (PE) is the most common congenital chest wall anomaly with a reported incidence of 1/300 to 1/400 live births and a male predominance. Preoperative evaluation of defect severity typically requires a calculation of the Haller index (HI) and/or correction index (CI) using computed tomography (CT) or x-rays. The purpose of this study was to determine whether physician-estimated depth (PED), a bedside screening tool, could be used to identify a subset of pediatric patients in whom CT was unnecessary. METHODS: After institutional review board approval (IRB #032018-091), we retrospectively reviewed all patients with a diagnosis of PE between 2009 and 2018 at our academic pediatric center. Demographic information including age, sex, and body mass index were abstracted. Imaging was reviewed to obtain HI and CI and to retrospectively calculate PED. The PED is calculated at the bedside by measuring the depth of the pectus at the site of greatest depression relative to a horizontal surface laid across the deformity. For this retrospective study, we calculated the CT-derived PED by measuring the depth from the horizontal on the respective CT images. Patients without imaging studies and patients with pectus carinatum, arcuatum, or mixed deformities were excluded from this study. RESULTS: A total of 94 patients met inclusion criteria. Of these, 82% were male, with a median age of 15 y. Patients were further subdivided by BMI, with 46% of patients having a BMI of <18.5 kg/m2 (i.e., underweight), whereas 54% of patients had a BMI of ≥18.5 kg/m2. Using a threshold PED of 2 cm, patients with a BMI of <18.5 kg/m2 had correct classification rates of 93% and 95% using PED relative to HI and CI, respectively. Patients with a BMI of ≥18.5 kg/m2 had correct classification rates of 80% and 88% using PED relative to HI and CI, respectively, at the same 2 cm threshold. CONCLUSIONS: PED is a viable screening tool for the preoperative evaluation of PE with a 2 cm threshold providing the combination of high sensitivity, specificity, and correct classification rates especially in underweight patients.

Use of Laparoscopy in Pediatric Blunt and Spleen Injury: An Unexpectedly Common Procedure After Cessation of Bleeding.

Background: Recently, several series have reported the use of laparoscopy in pediatric trauma, most commonly for bowel and pancreatic injury within the first 12 or 24 hours. During a multicenter trial at 10 Level 1 pediatric trauma centers, selective use of laparoscopy in children with blunt liver or spleen injury (BLSI) was noted. A secondary analysis was performed to describe the frequency and application of these procedures to pediatric BLSI. Patients and Methods: Prospective data were collected on all children age ≤18 years with BLSI presenting to 1 of 10 pediatric trauma centers. An unplanned secondary analysis of children who underwent laparoscopy was done. Results: Of 1008 children with BLSI, 59 initially underwent a laparotomy, but 11 underwent a laparoscopic procedure during their index admission; 1 of these was 22 hours postlaparotomy and 2 others were laparoscopy-assisted and converted to laparotomy. Median age of patients undergoing a laparoscopic procedure was 11.5 years (interquartile range [IQR]: 5.8-16.4). Laparoscopy was performed at 7 of the 10 centers. Median time to surgery was 42 hours (IQR: 8-96). Most patients had a liver (n = 6) injury; 4 had spleen and 1 had both. One of the laparoscopies was for pancreatic surgery, and 2 were for bowel injury (but converted to open). Conclusions: Laparoscopy was utilized in 16% of children requiring abdominal surgery after BLSI, with a median time of 42 hours postinjury. Uses included diagnostic laparoscopy, drain placement, laparoscopic pancreatectomy, and washout of hematoma.

Massive transfusion in pediatric trauma: An ATOMAC perspective.

BACKGROUND/PURPOSE: Massive transfusion protocols (MTPs) are considered valuable in pediatric trauma. Important questions regarding the survival benefit and optimal blood component ratio remain unknown. METHODS: The study time frame was January 2007 through December 2013 five Level I Pediatric Trauma Centers reviewed all trauma activations involving children ≤18 years of age. Included were patients who either had the institutional MTP or received >20 mL/kg or > 2 units packed red blood cells (PRBCs). RESULTS: 110/202 qualified for inclusion. Median age was 5.9 years (3.0-11.4). 73% survived to discharge; median hospitalization was 10 (3.1-22.8) days. Survival did not vary by arrival hemoglobin (Hgb), gender or age. Partial prothrombin time (PTT), INR, GCS and injury severity score (ISS) significantly differed for nonsurvivors (all p < 0.05). Logistic regression found increased mortality (OR 3.08 (1.10-8.57), 95% CI; p = 0.031) per unit increase over a 1:1 ratio of pRBC:FFP. CONCLUSION: In pediatric trauma pRBC:FFP ratio of 1:1 was associated with the highest survival of severely injured children receiving massive transfusion. Ratios 2:1 or ≥3:1 were associated with significantly increased risk of death. These data support a higher proportion of plasma products for pediatric trauma patients requiring massive transfusion. LEVEL OF EVIDENCE: Level IV.

Reimaging in pediatric blunt spleen and liver injury.

BACKGROUND: APSA guidelines do not recommend routine reimaging for pediatric blunt liver or spleen injury (BLSI). This study characterizes the symptoms, reimaging, and outcomes associated with a selective reimaging strategy for pediatric BLSI patients. METHODS: A planned secondary analysis of reimaging in a 3-year multi-site prospective study of BLSI patients was completed. Inclusion required successful nonoperative management of CT confirmed BLSI without pancreas or kidney injury and follow up at 14 or 60 days. Patients with re-injury after discharge were excluded. RESULTS: Of 1007 patients with BLSI, 534 (55%) met inclusion criteria (median age: 10.18 [IQR: 6, 14]; 62% male). Abdominal reimaging was performed on 27/534 (6%) patients; 3 of 27 studies prompting hospitalization and/or intervention. Abdominal pain was associated with reimaging, but decreased appetite predicted imaging findings associated with readmission and intervention. CONCLUSION: Selective abdominal reimaging for BLSI was done in 6% of patients, and 11% of studies identified radiologic findings associated with intervention or re-hospitalization. A selective reimaging strategy appears safe, and even reimaging symptomatic patients rarely results in intervention. Reimaging after 14 days did not prompt intervention in any of the 534 patients managed nonoperatively. LEVEL OF EVIDENCE: Level II, Prognosis.

Adherence to APSA activity restriction guidelines and 60-day clinical outcomes for pediatric blunt liver and splenic injuries (BLSI).

BACKGROUND: After NOM for BLSI, APSA guidelines recommend activity restriction for grade of injury +2 in weeks. This study evaluates activity restriction adherence and 60 day outcomes. METHODS: Non-parametric tests and logistic regression were utilized to assess difference between adherent and non-adherent patients from a 3-year prospective study of NOM for BLSI (≤18 years). RESULTS: Of 1007 children with BLSI, 366 patients (44.1%) met the inclusion criteria of a completed 60 day follow-up; 170 (46.4%) had liver injury, 159 (43.4%) had spleen injury and 37 (10.1%) had both. Adherence to recommended activity restriction was claimed by 279 (76.3%) patients; 49 (13.4%) reported non-adherence and 38 (10.4%) patients had unknown adherence. For 279 patients who adhered to activity restrictions, unplanned return to the emergency department (ED) was noted for 35 (12.5%) with 16 (5.7%) readmitted; 202 (72.4%) returned to normal activity by 60 days. No patient bled after discharge. There was no statistical difference between adherent patients (n = 279) and non-adherent (n = 49) for return to ED (χ2 = 0.8 [p < 0.4]) or readmission (χ2 = 3.0 [p < 0.09]); for 216 high injury grade patients, there was no difference between adherent (n = 164) and non-adherent (n = 30) patients for return to ED (χ2 = 0.6 [p < 0.4]) or readmission (χ2 = 1.7 [p < 0.2]). CONCLUSION: For children with BLSI, there was no difference in frequencies of bleeding or ED re-evaluation between patients adherent or non-adherent to the APSA activity restriction guideline. LEVEL OF EVIDENCE: Level II, Prognosis.

Negative Focused Abdominal Sonography for Trauma examination predicts successful nonoperative management in pediatric solid organ injury: A prospective Arizona-Texas-Oklahoma-Memphis-Arkansas + Consortium study.

BACKGROUND: Focused Abdominal Sonography for Trauma (FAST) examination has long been proven useful in the management of adult trauma patients, however, its utility in pediatric trauma patients is not as proven. Our goal was to evaluate the utility of a FAST examination in predicting the success or failure of nonoperative management (NOM) of blunt liver and/or spleen (BLSI) in the pediatric trauma population. METHODS: A retrospective analysis of a prospective observational study of patients younger than 18 years presenting with BLSI to one of ten Level I pediatric trauma centers between April 2013 and January 2016. 1,008 patients were enrolled and 292 had a FAST examination recorded. We analyzed failure of NOM of BLSI in the pediatric trauma population. We then compared FAST examination alone or in combination with the pediatric age adjusted shock index (SIPA) as it relates to success of NOM of BLSI. RESULTS: Focused Abdominal Sonography for Trauma examination had a negative predictive value (NPV) of 97% and positive predictive value (PPV) of 13%. The odds ratio of failing with a positive FAST examination was 4.9 and with a negative FAST was 0.20. When combined with SIPA, a positive FAST examination and SIPA had a PPV of 17%, and an odds ratio for failure of 4.9. The combination of negative FAST and SIPA had an NPV of 96%, and the odds ratio for failure was 0.20. CONCLUSION: Negative FAST is predictive of successful NOM of BLSI. The addition of a positive or negative SIPA score did not affect the PPV or NPV significantly. Focused Abdominal Sonography for Trauma examination may be useful clinically in determining which patients are not at risk for failure of NOM of BLSI and do not require monitoring in an intensive care setting. LEVEL OF EVIDENCE: Prognostic study, level IV; therapeutic/care management, level IV.

Enhanced neonatal surgical site infection prediction model utilizing statistically and clinically significant variables in combination with a machine learning algorithm.

BACKGROUND: Machine-learning can elucidate complex relationships/provide insight to important variables for large datasets. This study aimed to develop an accurate model to predict neonatal surgical site infections (SSI) using different statistical methods. METHODS: The 2012-2015 National Surgical Quality Improvement Program-Pediatric for neonates was utilized for development and validations models. The primary outcome was any SSI. Models included different algorithms: full multiple logistic regression (LR), a priori clinical LR, random forest classification (RFC), and a hybrid model (combination of clinical knowledge and significant variables from RF) to maximize predictive power. RESULTS: 16,842 patients (median age 18 days, IQR 3-58) were included. 542 SSIs (4%) were identified. Agreement was observed for multiple covariates among significant variables between models. Area under the curve for each model was similar (full model 0.65, clinical model 0.67, RF 0.68, hybrid LR 0.67); however, the hybrid model utilized the fewest variables (18). CONCLUSIONS: The hybrid model had similar predictability as other models with fewer and more clinically relevant variables. Machine-learning algorithms can identify important novel characteristics, which enhance clinical prediction models.

The incidence of delayed splenic bleeding in pediatric blunt trauma.

BACKGROUND: One of the concerns associated with nonoperative management of splenic injury in children has been delayed splenic bleed (DSB) after a period of hemostasis. This study evaluates the incidence of DSB from a multicenter 3-year prospective study of blunt splenic injuries (BSI). METHODS: A 3-year prospective study was done to evaluate nonoperative management of pediatric (≤18years) BSI presenting to one of 10 pediatric trauma centers. Patients were tracked at 14 and 60days. Descriptive statistics were used to summarize patient and injury characteristics. RESULTS: During the study period, 508 children presented with BSI. Median age was 11.6 [IQR: 7.0, 14.8]; median splenic injury grade was 3 [IQR: 2, 4]. Nonoperative management was successful in 466 (92%) with 18 (3.5%) patients undergoing splenectomy at the index admission, all within 3h of injury. No patient developed a delayed splenic bleed. At least one follow-up visit was available for 372 (73%) patients. CONCLUSION: A prior single institution study suggested that the incidence of DSB was 0.33%. Based on our results, we believe that the rate may be less than 0.2%. LEVEL OF EVIDENCE: Level II, Prognosis.

Hypotension and the need for transfusion in pediatric blunt spleen and liver injury: An ATOMAC+ prospective study.

PURPOSE: Children with blunt liver or spleen injury (BLSI) requiring early transfusion may present without hypotension despite significant hypovolemia. This study sought to determine the relationship between early transfusion in pediatric BLSI and hypotension. METHODS: Secondary analysis of a 10-institution prospective observational study was performed of patients 18years and younger presenting with BLSI. Patients with central nervous system (CNS) injury were excluded. Children receiving blood transfusion within 4h of injury were evaluated. Time to first transfusion, vital signs, and physical exams were analyzed. Patients with hypotension were compared to those without hypotension. RESULTS: Of 1008 patients with BLSI, 47 patients met inclusion criteria. 22 (47%) had documented hypotension. There was no statistical difference in median time to first transfusion for those with or without hypotension (2h vs. 2.5h, p=0.107). The hypotensive group was older (median 15.0 versus 9.5years; p=0.007). Median transfusion volume in the first 24h was 18.2mL/kg (IQR: 9.6, 25.7) for those with hypotension and 13.9mL/kg (IQR: 8.3, 21.0) for those without (p=0.220). Mortality was 14% (3/22) in children with hypotension and 0% (0/25) in children without hypotension. CONCLUSION: Hypotension occurred in less than half of patients requiring early transfusion following pediatric BLSI suggesting that hypotension does not consistently predict the need for early transfusion. TYPE OF STUDY: Secondary analysis of a prospective observational study. LEVEL OF EVIDENCE: Level IV cohort study.