To date, there are no clear guidelines from the National Institute of Clinical Excellence or the British Orthopaedic Association regarding the use of Autologous
This study aimed to identify factors associated with increased rates of blood transfusion in patients with adolescent idiopathic scoliosis (AIS) treated with posterior spinal fusion (PSF). A retrospective case-control study was performed for AIS patients treated at a large children's hospital between August 2018 and December 2020. All patients with a diagnosis of AIS were evaluated. Data on patient demographics, AIS, and transfusion parameters were collected. Univariate regression and multivariate logistic modeling were utilized to assess risk factors associated with requiring transfusion. Odds ratios (OR) and 95% confidence interval (CI) were calculated. Surgeries were done by three surgeons and thirty anesthesiologists. To quantify the influence of anesthesia practice preferences a categorical variable was defined as “higher-transfusion practice preference”, for the provider with the highest rate of transfusion. A total of 157 AIS patients were included, of whom 56 were transfused RBC units (cases), and 101 did not receive any RBC transfusion (controls). On univariate analysis, the following variables were significantly correlated with receiving RBC transfusion: “higher-transfusion practice preference,” “administration of crystalloids,” “receiving fresh frozen plasma (FFP),” “receiving platelets,” “pre-operative hemoglobin,” “cell saver volume,” and “surgical time.” On multiple regression modeling, “pre-operative hemoglobin less than 120 g/L” (OR 14.05, 95% CI: 1.951 to 135.7) and “higher-transfusion practice preference” (OR 11.84, 95% CI: 2.505 to 63.65) were found to be meaningfully and significantly predictive of RBC transfusion. In this cohort, we identified pre-operative hemoglobin of 120 g/L as a critical threshold for requiring transfusion. In addition, we identified significant contribution from anesthesia transfusion practice preferences. Our multivariate model indicated that these two factors are the major significant contributors to allogenic blood transfusion. Although further studies are required to better understand factors contributing to transfusion in AIS patients, we suggest standardized, peri-operative evidence-based strategies to potentially help reduce variations due to individual provider preferences.
Blood transfusion requirement after primary total hip replacements (THR) and total knee replacements (TKR) was found to be related to increased post-operative complications rate and length of hospital stay. Pre-operative haemoglobin level remains the single most important factor determining the requirement for post-operative blood transfusion. We carried out a local retrospective audit of 977 THRs and TKRs in 2019. Pre-operative and pre-transfusion haemoglobin levels for transfused group of patients were recorded.Abstract
Background
Methods
Blood donation in England is voluntary and a limited resource. Blood transfusion is essential and beneficial in some postoperative hip replacements, however is not without inherent risks. Royal College of Physician audit in 2007 has shown wide variation in transfusion with an average rate of 25% (22% – 97%). Patient blood management is an established approach to optimising need for post- operative transfusion. The Surgical Blood Conservation Service (SBCS) was set up in 2009 to enable a reduction in the demand for blood transfusion during and postoperatively in many orthopaedic procedures. We aimed to achieve preoperative haemoglobin of 12g/dl (males) and 11g/dl (females). Low levels were treated with iron therapy. Surgery was deferred till satisfactory Hb levels were reached. During surgery cell salvage was routinely used. Transfusion was recommended at postoperative Hb < 8g/dl. The transfusion rate was estimated at 47% in 2002. Following the introduction of SCBS, the transfusion rate reduced considerably to 7.9% in 2009 with a further reduction to 7.29% in 2011 and 3.16% in 2012. In 2013, 10 out of 442 hip replacements received transfusion (2.21%). Our results demonstrate successful Patient blood management, minimising the need for post- operative transfusion.
Patients undergoing Joint Arthroplasty received a significant proportion of blood transfusions. In this study, we compared the risk of Deep Infection, and Superficial Infection post operation following Primary Total Hip or Knee replacement in blood-transfused and non-blood-transfused patients. Cohort of patients who underwent primary total Hip or Knee Arthroplasty from April 2012 to March 2015 in Alberta. Patient characteristics, comorbidity, received blood transfusion were collected from electronic medical records, operating room information systems, discharge abstract database, provincial clinical risk grouper data. Deep Infection and Superficial Infection were captured from Provincial Surgical Site Infection Surveillance data. Deep Infection include deep incisional and organ/space infections. Logistic regression analysis were used to compare Deep Infection and Superficial Infection in blood-transfused and non-blood-transfused cohorts, and risk-adjusted for age, gender, procedure type, and co-morbidities. Our study cohort contains 27891 patients, with mean of age at admission was 66.3±10.4, 57.5% female, 49.3% had 1 or more comorbidities. 58.8% underwent Knee Replacement. 11.1% received blood transfusion during hospital stay (Total Hip Replacement (THR) =13.1% and Total Knee Replacement (TKR) =9.7%,). 1.1% had Deep Infection (THR=1.4% and TKR=0.9%) and 0.5% had Superficial Infection (THR=0.5% and TKR=0.5%). Blood-transfused patients got 1.7% Deep Infection and 1.0% Superficial infection. Non-blood-transfused patients got 1.0% Deep Infection and 0.5% Superficial infection. Controlling for age, gender, procedure type, and co-morbidities, the odds of Deep Infection were 1.6 times higher for blood-transfused patients than for non-blood-transfused patients (adjusted odds ratio [OR]=1.6, 95% confidence interval [CI] [1.2–2.2], p=0.004). The odds of Superficial Infection were 2.0 times higher for transfused patients (adjusted OR=2.0, 95% CI [1.3–3.0], p=0.002). Blood transfusion increases Deep Infection and Superficial Infection post-surgery following Primary Total Knee or Hip Replacement. This finding suggests to reduce the unnecessary blood transfusion for patients considering Joint Arthroplasty. Reducing the blood transfusion will save the inpatient cost and decrease the infective complications post-surgery in Hip or Knee Arthroplasty patients.
Surgery for DDH is one of the common paediatric orthopaedics procedures in a tertiary care paediatrics hospital. There are no uniformly agreed guidelines about the pre-operative work up related to blood transfusion in DDH surgery. This leads to lack of uniformity in practice, sometimes causes cancellations of operations on the day of surgery (due to no cross matched blood available) and on other occasions wastage of the cross matched blood. The aims of our study were to know the incidence of perioperative blood transfusion in a series of DDH operations and to determine what types of operations/kids have more chances of needing a blood transfusion peri-operatively. We included all children who had surgery for DDH between April 2009 and October 2012 in our institution. We found out which of these children had blood transfusion peri-operatively and reviewed their notes to determine any trends in transfusion requirements 165 children had operations for DDH during the study period. This included operations ranging from hip open reduction to Ganz osteotomy. 6 out of 165 (4%) were transfused blood. Children needing blood transfusion tended to be older and had multiple hip operations previously. Only 3 (2 during Ganz and 1 during bilateral hip reconstruction) of these 6 children needed intra-operative blood transfusion. None of the under 4 years old children needed intra-operative blood transfusion. We conclude that children for unilateral primary hip operations for DDH do not need pre operative blood cross match. A group and save is enough in these cases.
Conflicting results about the impact of blood transfusions on outcomes after total knee arthroplasty (TKA) have been reported. We hypothesized that transfusions would be associated with greater readmission and complication rates after primary TKA. We conducted a retrospective cohort study of the 100% 2008 Medicare Provider Analysis and Review database, and identified primary THA patients by ICD9 codes and excluded fractures/ER admissions to select for elective cases. Patients who received a perioperative blood transfusion (6,951 patients) were compared to a control group who did not receive transfusion (332,762 patients). Descriptive statistics of age, sex, race, diagnosis for surgery, Elixhauser comorbidities, mortality (inpatient, 30, 60, and 90 days and 2 years), readmissions (30, 60, and 90 days), complications (medical and surgical at 30 and 90 days), and revision at 2 years were assessed for both groups. Continuous variables were compared with Student's T-test and categorical variables with chi-square test. Multivariate logistic regression models were constructed to assess the association of transfusion with readmissions, complications, and revisions. Statistical significance was set at p < 0.01.Background
Methods
There is growing clinical and policy emphasis on minimizing transfusion use in elective joint arthroplasty, but little is known about the degree to which transfusion rates vary across US hospitals. This study aimed to assess hospital-level variation in use of allogeneic blood transfusion in patients undergoing elective joint arthroplasty, and to characterize the extent to which variability is attributable to differences in patient and hospital characteristics. The study population included 228,316 patients undergoing total knee arthroplasty (TKA) at 922 hospitals and 88,081 patients undergoing total hip arthroplasty (THA) at 606 hospitals from January 1, 2009, to December 31, 2011, in the Nationwide Inpatient Sample database, a 20% stratified sample of US community hospitals.Background
Methods
Perioperative blood management remains a challenge during total hip and total knee arthroplasty (THA and TKA, respectively). The purpose of this study was to determine the impact of body mass index (BMI) on blood transfusion in THA and TKA. We retrospectively evaluated 2399 patients, of whom 896 underwent THA and 1503 had TKA. A variety of outcome variables were assessed for their relationship to BMI which was stratified using the World Health Organization (WHO) classification scheme (Normal <25 kg/m2, Overweight 25–30, and Obese >30). Increased BMI was found to be protective of blood transfusion in both THA and TKA patients. Among THA patients, transfusion rates were 34.8%, 27.6% and 21.9% for normal, overweight and obese categories respectively (p = 0.002). TKA transfusion rates were 17.3%, 11.4% and 8.3% for the same categorization of BMI (p = 0.002). No trends were identified for a relationship between BMI and deep vein thrombosis, pulmonary embolism, myocardial infarction, discharge location, length of stay, 30-day readmission rate and preoperative hemoglobin level. Elevated BMI was significantly associated with decreased age, increased Hemoglobin A1c, increased baseline creatinine, increased OR time, increased American Society of Anesthesiologists (ASA) score and increased estimated blood loss in both THA and TKA patients. There was a statistically significant trend toward increased deep surgical site infection in THA patients (p = 0.043).
Arthroplasties of hip and knee are associated with blood loss, which may lead to adverse patient outcome. Jehovah's Witnesses do not accept blood transfusion. Performing arthroplasties in Witness patients without transfusion has been a matter of concern. We developed a protocol, which avoids transfusion in arthroplasties of Witness patients, and evaluated the feasibility and safety of the protocol. Our protocol consisted of subcutaneous administration of 4000 U recombinant erythropoietin and 100 mg of intravenous iron supplements when patient's hemoglobin level was less than 10 g/dL in preoperative evaluation. During the operation, cell saver, and plasma expander were used. Postoperatively, recombinant erythropoietin was administered three times a week and iron supplements were administered daily until the hemoglobin level reached 10 g/dL. We evaluated the feasibility of our protocol, perioperative complications and hematologic changes.Introduction
Materials and Methods
Primary total knee arthroplasty (TKA) is associated with perioperative bleeding, and some patients will require allogenic blood transfusion during their inpatient admission. While blood safety has improved in the last several decades, blood transfusion still carries significant complications and costs. Transfusion indications and alternative methods of blood conservation are being explored. However, there is limited nationally representative data on allogenic blood product utilization among TKA patients, and its associated outcomes and financial burden. The purpose of this study was to use a national administrative database to investigate the trends in utilization and outcomes (i.e. in-hospital mortality, length of stay, admission costs, acute complications) of allogenic blood transfusion in primary TKA patients. The Nationwide Inpatient Sample (NIS), the largest all-payer inpatient care database representing a 20% stratified sample of United States hospitals, was utilized. Primary TKA (ICD-9-CM 81.54) cases from 2000 to 2009 were retrospectively queried (n = 4,544,999; weighted national frequency). A total of 67,841 admissions were excluded (Figure 1). The remaining 4,477,158 cases were separated into two study cohorts: (1) patients transfused with allogenic blood products (red blood cells, platelets, serum) (n = 540,270) and (2) patients not transfused (n = 3,936,888). Multivariable regression and generalized estimating equations were used to examine the effect of transfusion on outcomes, adjusting for patient/hospital characteristics and comorbidity.Introduction:
Methods:
In a prospective randomised controlled trial, 51 patients who did not receive a bone plug during total knee replacement surgery were compared to 49 patients who received a bone plug. The primary outcome measure was the need for allogenic blood transfusion requirement and the secondary outcome was the post-operative blood loss and decline in haemoglobin levels. The patients had autologous re-transfusion from their closed drainage system. The two groups did not differ in the demographics. The mean intra-operative blood loss was slightly more in the no plug group (difference of 41.25 millilitres), which was not statistically significant. There was no statistically significant difference in total post-operative blood loss and drop in haemoglobin levels. Only one patient had two units of allogenic blood transfusion in the no bone plug group while none required allogenic blood in the bone plug group. There was no statistically significant difference in the amount of blood re-transfused from the drain between the two groups. Our findings did not show any statistically significant difference in post-operative blood loss, decline in haemoglobin levels and the need for allogenic blood transfusion in total knee replacement surgery.
One-stage bilateral total hip arthroplasty (THA) is twice as invasive as unilateral THA. Therefore, increases in bleeding, postoperative anemia, and complications are a concern. The purpose of this study was to investigate hemoglobin values and the use of autologous and allogenic blood transfusion after one-stage bilateral THA. Twenty-nine patients (7 men and 22 women; 58 hips) were treated with one-stage bilateral THA. The mean age of subjects at the time of surgery was 60.6 years. The average body mass index for patients was 21.7 kg/m2. The diagnoses were secondary osteoarthritis due to developmental dysplasia of the hip (n=25) and avascular necrosis (n=4). All patients had donated 800 ml of autologous blood in 2 stages preoperatively (1 to 4 weeks apart). All patients took iron supplements starting from 5 weeks preoperatively. For all patients, the procedure was performed under general anesthesia in the lateral decubitus position via a posterolateral approach. Intra-operative blood salvage was not used. Suction drains were inserted subfascially. As a general rule, pre-donated autologous blood was transfused back to the patients intra- or post-operatively. Allogenic blood transfusion was performed when clinical symptoms of anemia occurred (hypotension, low urinary output, tachycardia, etc.) rather than using a preset blood threshold (hemoglobin level <8 g/dl). To determine changes in blood pressure following surgery until the next morning, systolic and diastolic blood pressure were measured at 3-hr intervals.Background
Methods
Geriatric hip fracture patients have a 14-fold higher 30-day mortality than their age matched peers. Up to 50% of these patients receive blood transfusion perioperatively. Both restrictive and liberal transfusion policies are controversial in this population. Aim: The longitudinal description of transfusion practice in geriatric hip fracture patients in a major trauma centre. An 8-year (2002–2009) retrospective study was performed on patients over the age of 65 undergoing hip fracture fixation. Yearly transfusion rate; the influence of transfusion on 30-day, 90-day and 1-year mortality and length of stay (LOS) was investigated. On admission haemoglobin (Hb), pre-transfusion Hb and post-transfusion Hb and their effect on transfusion requirement and mortality was also reviewed. The yearly changes in on-admission and pre-transfusion Hb were also examined. The influence of comorbidities, timing, procedure performed and operation duration on transfusion requirement and mortality was also studied. From the 3412 patients, 35% (1195) received transfusion during their hospital stay. There was no change in age, gender and co-morbidities during the study. Thirty-day mortality improved from 12.4% in 2002 to 7% in 2009. The transfusion rate showed a gradual decrease from the highest of 48.3% (2003) to 22.9% (2009) (Pearson correlation - R2 = −0.707, p=0.05). There was no change during the study period in on-admission and pre-transfusion Hb. The mortality for non-transfused and transfused patients was [9.6% vs. 10.3 % (30-day)], [17.2% vs. 18.4%(90-day)] and [27% vs. 30.5%(1-year), p=0.031]. LOS was 11±9 for non-transfused patients and 13±10 (p<0.001) for transfused patients. Patients with more comorbidities experienced a higher transfusion rate, (0 – 31%, 1 – 38%, 2 – 46%, 3 – 57%), (Pearson Chi-squared, p<0.001). The need for transfusion by different procedures in decreasing order was 47.6% intramedullary device, 44.0% DHS, 25.2% cemented hemiarthroplasty, 23.6% Austin-Moore, and 5.5% cannulated screws. The length of the operation increases the chance of transfusion (<1hrs, – 33%, 1–2hrs – 35%, 2–3hrs – 41%, >3 hours – 65%), (Pearson Chi-squared, p=0.010). Preoperative waiting time had no influence on transfusion frequency (<24hrs – 36%, 24–48hrs – 34%, 48–96hrs – 36%, >96hrs – 33%), (Pearson Chi-squared, p=0.823). The percentage of transfused geriatric hip fracture patients halved during the eight-year period without changes in demographics and co-morbidities. Perioperative transfusion of hip fracture patients is associated with higher 1-year mortality and increased LOS. A more restrictive transfusion practice has been safe and may be a factor in the improved 30-day mortality.
Early rehabilitation and discharge following minimally-invasive total hip arthroplasty has potential risks including the possibility that patients may become progressively anemic at home. The current study assess the use of pre-emptive autologous blood transfusion on the length of stay, readmission, and allogenous transfusion. Patients treated by primary total hip arthroplasty using the superior capsulotomy technique were studied. Patients were divided into two groups. Group 1 were patients who did donate autologous blood and received an intra-operative pre-emptive transfusion. There were 283 patients in Group 1. Group 2 were patients who were medically capable of donating autologous blood but did not for non-medical reasons. There were 71 patients in Group 2. Patients who did not donate autologous blood for medical reasons (preoperative Hgb less than 11.5, age over 80) were excluded. All patients received general anesthesia. Length of stay, allogenous transfusion and readmission were compared.Introduction
Methods
Wound complications are common in patients with soft tissue sarcomas (STS) treated with surgical excision. Limited data is available on predictive factors for wound complications beyond the relationship to neo-adjuvant or adjuvant radiotherapy. Likewise, the association between blood transfusion, patient comorbidities and post-operative outcomes is not well described. In the present study we identified the predictive factors for blood transfusion and wound complications in patients undergoing surgical resection of soft tissue sarcoma from a national cohort. The American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) database was used to identify patients who underwent surgical resection of a STS from 2005 to 2013. Primary malignant soft tissue neoplasms were identified using the following ICD-9 codes: 171.2, 171.3 and 171.6. Patients treated with both wide excision and amputation were identified using the current procedural terminology (CPT) codes. Prolonged operative time was defined as greater than 90th percentile of time required per procedure. A multivariable logistic regression model was used to identify associations between patient factors and post-operative wound complications (superficial and deep surgical site infections (SSI), and wound dehiscence). A similar regression model sought to identify prognostic factors for blood transfusion and associations with post-operative outcomes. A total of 788 patients met our inclusion criteria. Of theses, 64.2% had tumours in the lower limb, 23.1% patients had tumours in the upper limb, and 12.7% patients had pelvic tumours. Six hundred and forty patients (81.2%) underwent surgical excision; 148 (18.8%) patients had an amputation. Multivariable logistic regression modeling identified American Society of Anaesthesiologist (ASA) class 3 and 4 (OR=2.3, P=0.03; OR=8.3, P=0.001, respectively), amputation (OR=14.0, P<0.001) and prolonged operative time (OR=4.6, P<0.001) as significant predictors of blood transfusion. Radiotherapy (OR=2.6, P=0.01) and amputation (OR=2.6, P=0.01) were identified as predictors of superficial SSI, whereas ASA class 4 (OR=6.2, P=0.03), prolonged operative time (OR=3.9, P=0.012) and return to the operating room (OR=10.5, P<0.001) were associated with deep SSI. Male gender (OR=1.8, P=0.03), diabetes (OR=2.3, P=0.03), ASA class 3 (OR=2.4, P=0.003), amputation (OR=3.8, P<0.001) and steroids (OR=4.5, P=0.03) were identified as predictors for wound dehiscence and open SSI. A national cohort demonstrates that male gender, diabetes, chronic steroid use, higher ASA score and radiotherapy are associated with an increased incidence of wound complications. One in twenty-three patients undergoing resection of an STS will require a blood transfusion, and this risk is correlated with amputation, prolonged operative time and increased ASA score. Strategies to decrease the risk of blood transfusion and wound complication should be considered for these patient groups.
Tranexamic acid is a potent antifibrinolytic which has shown efficacy in reducing blood loss in total knee arthroplasty when administered intravenously. We performed a randomised controlled trial of oral tranexamic acid in total knee arthroplasty in order to assess the blood sparing effect of this preparation. We investigated the effects of oral tranexamic acid on blood loss in 50 patients (25 treatment arm and 25 placebo) undergoing unilateral total knee replacement in a two year period starting January 2007. The treatment arm received 1500 mg of encapsulated oral tranexamic acid TDS pre-operatively, with the third dose occurring within two hours of surgery, and a fourth dose six hours post surgery. The control arm received an identically encapsulated non-active formulation at the same dosing intervals. Baseline pre-operative haemoglobin and heamatocrit measures were collected. Outcome measures were post-operative haemoglobin and haematocrit taken 12 to 24 hours post operatively and total blood loss in wound drains at 24 hours. Results showed a non-clinically significant trend towards decreased blood loss and transfusion rates in the treatment arm when compared to placebo. No significant adverse events occurred in relation to the use of oral Tranexamic acid in this study. The perioperative use of oral tranexamic acid in conjuntion with elective total knee arthroplasty appears safe; however, its efficacy as a blood sparing medication is less than that which has been recorded with intravenous dosing. The study supports further consideration of the availability of intravenous tranexamic acid for decreasing blood loss in orthopaedic arthroplasty.
Hemorrhage and transfusion requirements in spine surgery are common. This is especially true for thoracic and lumbar fusion surgeries. The purpose of this papersi to determine predictive factors for transfusion and their effect on short-term post-operative outcomes for thoracic and lumbar fusions. The American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) database was used to identify patients that underwent lumbar or thoracic fusion surgery from 2010 to 2013. Univariate and multivariate regression analysis was used to determine predictive factors and post-operative complications associated with transfusion. A total of 14,249 patients were included in this study; 13,586 had lumbar fusion and 663 had thoracic fusion surgery. The prevalence of transfusion was 35% for thoracic fusion and 17.5% for lumbar fusion. The multivariate analysis showed that age between 50–60 (OR 1.38, CI: 1.23–1.54), age between 61–70 (OR 1.65, CI: 1.40–1.95), dyspnea (OR 1.11, CI: 1.02–1.23), hypertension (OR 1.14, CI: 1.02–1.27), ASA class (OR 1.73, 1.18–1.45), pre-operative blood transfusion (OR 1.91, CI: 1.04–3.49), and extended surgical time (OR 4.51, CI: 4.09–4.98) were predictors of blood transfusion requirements for lumbar fusion. While only pre-operative BUN (OR 1.04, CI: 1.01–1.06) and extended surgical time (OR 4.70, CI: 3.12–6.96) were predictors of transfusion for thoracic fusion. In contrast, higher pre-operative hematocrit was protective against transfusion. Patients transfused who underwent lumbar fusion had an increased risk to develop superficial wound infection, deep wound infection, venous thromboembolism, myocardial infarction and had longer length of hospital stay. Patients transfused who underwent thoracic fusion were more likely to have venous thromboembolism and extended length of hospital stay. However, mortality was not associated with blood transfusion. This study used a large database to characterise the incidence, predictors and post-operative complications associated with blood transfusion in thoracic and lumbar fusion surgeries. Pre- and post-operative planning for patients deemed to be at high-risk of requiring blood transfusion should be considered to reduce post-operative complication in this population.
Tranexamic acid (TXA) is an effective medication to limit blood loss and transfusion requirements in association with contemporary total joint arthroplasty. TXA is in a class of medications termed anti-fibrinolytics due to their action to limit the breakdown of clot that has already been formed. It is useful to note that TXA does not promote the formation of clot, it simply limits the breakdown of already established clot. A recent systematic review and meta-analysis of randomised clinical trials of TXA use in total hip replacement demonstrated: 1) a substantial reduction in the proportion of patients who required transfusion and 2) no increase in DVT or PE. Similarly a recent Cochrane Database systematic review assessed Anti-fibrinolytic Use for Minimizing Perioperative
London's Air Ambulance (LAA) was first set-up in 1989 as a direct result of a Royal College of Surgeons of England Report highlighting poor trauma care provision. Since its inception, the service's mission is to be an innovative and effective provider of advanced pre-hospital care. The service provides a senior Doctor and senior Paramedic to the scene of any incident within the M25 by helicopter, during the day, and by fast-response car at night. The vast majority of doctors are usually Emergency Medicine Physicians or Anaesthetists. During a 6-month tenure, doctors will usually have completed a number of procedures, which include rapid sequence induction of anaesthesia, pre-hospital blood transfusion, and, procedural sedation. In terms of innovations, the organisation was the first in the UK to provide a 24/7 service. It was also the first to start pre-hospital Rapid Sequence Induction of Anaesthesia for the severely injured; Resuscitative Thoracotomy for the victims of penetrating trauma; and pre-hospital