Units Of Packed Red Blood Cells Research Articles

Cardiac iron overload assessed by T2* magnetic resonance imaging and cardiac function in regularly transfused myelodysplastic syndrome patients

Cardiac iron overload assessed by <scp>T</scp>2* magnetic resonance imaging and cardiac function in regularly transfused myelodysplastic syndrome patients

Putting Evidence Into Nursing Practice: Four Traditional Practices Not Supported by the Evidence

Evidence-based nursing practice is essential to the delivery of high-quality care that optimizes patients' outcomes. Studies continue to show improved outcomes when best evidence is used in the delivery of patient care. Despite awareness of the importance of practicing by using best evidence, achieving and sustaining evidence-based practice within practice environments can be challenging, and research suggests that integration of evidence-based practice into daily clinical practice remains inconsistent. This article addresses 4 practice issues that, first, are within the realm of nursing and if changed might improve care of patients and, second, are areas in which the tradition and the evidence do not agree and practice continues to follow tradition. The topics addressed are (1) noninvasive measurement of blood pressure in children, (2) oxygen administration for patients with chronic obstructive pulmonary disease, (3) intravenous catheter size and blood administration, and (4) infection control practices to prevent infections. The related beliefs, current evidence, and recommendations for practice related to each topic are described.

Reinforcing the Staple Line with Surgicel® Nu-knit® in Roux-en-Y Gastric Bypass: Comparison with Bovine Pericardial Strips

In the literature, staple line leak rate is reported to be 1-6%, and hemorrhage rate is 2-5% in laparoscopic Roux-en-Y gastric bypass (LRYGB). Various buttress materials are available in an attempt to reduce perioperative complications. The aims of our study are to evaluate the effect of using absorbable hemostat (SNK) as buttress material and compare its usage with bovine pericardial strips (PSD). Between January 2006 to May 2007 and from October 2007 to December 2009, a total of 1,074 patients underwent LRYGB at our institution. Of these 1,074 patients, PSD was used in 443 (41.2%) patients, and SNK was used in 631 (58.8%) patients. A retrospective review of a prospectively collected database was performed for all LRYGB patients, noting the outcomes and complications of the procedure. Five (1.1%) patients required transfusion of packed red blood cells (PRBC) during early postoperative period (postoperative 1-3days) in the PSD group, while two (0.3%) patients required transfusion in the SNK group. SNK patients received significantly lower mean units of PRBC (1.0 unit) when compared to that of PSD patients (5.0 units). One (0.2%) anastomotic leak was found in the PSD group on postoperative day (POD) 10. One (0.2%) patient in the SNK group also showed an anastomotic leak on POD 2. Additionally, the cost of SNK per procedure was significantly less than that of PSD. The use of absorbable hemostat as buttress material may be effective in reducing acute postoperative bleeding in LRYGB at a significantly lower cost.

Efficacy of a high FFP:PRBC transfusion ratio on the survival of severely injured patients: a retrospective study in a single tertiary emergency center in Japan

Recent studies have shown increased survival benefits when a high fresh frozen plasma (FFP) to packed red blood cell (PRBC) ratio is used during trauma resuscitation. However, some reports have raised questions about the effect of higher FFP:PRBC transfusion ratios. The aim of this study was to examine the efficacy of high FFP:PRBC ratios in injured patients with regard to survival and morbidity in a single tertiary emergency center in Japan. This study examined severe trauma patients who received 10 or more PRBC units during the first 24 h of admission. We examined the relationship between the FFP:PRBC ratios during the first 6 h and the patient outcome. The severity was similar among all groups. The mortality rate was 44.4% in the high (>1:1.5), 16.7% in the middle (1:1.5-1:2) and 33.3% in the low (<1:2) F:P ratio groups. Only one patient in the high group developed sepsis, and none of the patients developed ARDS. The current results indicate that the FFP:PRBC ratios during the first 6 h after admission might not affect the mortality or morbidity. However, differences between trauma care systems in Japan and other countries, along with other study limitations, necessitate that a subsequent prospective multicenter study be undertaken before any definitive conclusions can be made.

Impact of inverse ratios on patients with exsanguinating vascular injuries

Resuscitation strategies in patients with severe hemorrhage have evolved throughout the years. Optimal resuscitation ratios for civilian exsanguinating vascular injuries has not been determined. We hypothesize improved outcomes in patients with exsanguinating vascular injuries when an aggressive hemostatic resuscitation is used with an inverse ratio of fresh frozen plasma (FFP) to packed red blood cell (PRBC). This is a 5-year retrospective analysis of vascular injuries requiring hemostatic resuscitation. Resuscitation groups by ratios of FFP/PRBC were inverse (>1:1), high (1-1:2), and low (<1:2). Patients with 10 or greater units of PRBC (massively transfused patients) were evaluated in each of the resuscitation groups. Demographics and complications throughout hospital length of stay and were compared between the resuscitation groups. Survivability Kaplan-Meier curves were generated at 6 hours and 5 days. A total of 258 patients with vascular injuries required component therapy resuscitation (low, n = 78; high, n = 156; inverse, n = 24). Massively transfused patients (n = 162, 62.7%) showed a significant Kaplan-Meier survivability difference at 6 hours (low, 65.0% vs. high, 75.0% vs. inverse, 100%, p = 0.024) and at 5 days (low, 52.5% vs. high, 62.0% vs. inverse, 100%, p = 0.008). Moreover, for massively transfused patients with extremity vascular injuries (n = 65, 39%), a relationship between resuscitation ratio and amputations was significant (low vs. high vs. inverse was 36.8% vs. 12.8% vs. 0%, respectively; p = 0.033). This is the first study that highlights the potential outcomes benefits of an inverse ratio of FFP-PRBC in patients with exsanguinating vascular injuries. Multi-institutional prospective analysis is needed to potentially elucidate the cytoprotective effect of FFP to validate these results. Therapeutic study, level IV; diagnostic study, level III.

Intraoperative blood transfusion of one or two units of packed red blood cells is associated with a fivefold risk of stroke in patients undergoing elective carotid endarterectomy

Transfused blood can disrupt the coagulation cascade. We postulated that packed red blood cell (PRBC) transfusion may be associated with thromboembolic phenomena. We used propensity matching to examine the relationship between intraoperative PRBC transfusion and stroke during carotid endarterectomy (CEA). We selected CEA procedures from the American College of Surgeons National Surgical Quality Improvement Program database from 2005-2009. We excluded bilateral, redo, and emergent procedures. We used multivariate logistic regression to identify independent risk factors for stroke. We then calculated a transfusion propensity score to match patients who received one or two units of transfused PRBC intraoperatively with patients of similar risk profiles who had not been transfused. Our criteria resulted in 12,786 elective CEA patients. Of these, 82 (0.6%) received a one- to two-unit intraoperative transfusion. Thirty-day stroke rates were 1.4% (179/12,704) in the nontransfused group and 6.1% (5/82) in the transfused group (Fisher exact test, P = .007). In forward stepwise multivariable regression of risk factors, only hemiplegia, stroke history, and transient ischemic attacks were predictive of 30-day stroke. We used these same variables to calculate transfusion propensity. We matched 80 transfused patients with 160 controls, thus, creating two groups with very similar risk profiles differing only by their transfusion status. In the matched groups, there was a fivefold increase in the risk of stroke in transfused patients (Fisher exact test, P = .043) Intraoperative transfusion of one to two units of PRBCs is associated with a fivefold increase in stroke risk. This holds true after consideration of stroke risk variables and operative duration as a surrogate for technical difficulty. The increased risk may be related to several effects of transfused blood on the coagulation inflammation cascade.

Lead Content of Blood Transfusions for Extremely Low-Birth-Weight Infants

Our objective was to evaluate the levels of lead in blood transfusions for extremely low-birth-weight (ELBW) infants and how they compare with lead levels suspected of causing neurotoxicity. This prospective cohort included infants with a birth weight ≤ 1000 g. The quantity of transfused lead was calculated based on transfused volume and packed red blood cell (PRBC) unit lead levels. The results were compared with the exposure reference. Thirty-seven infants (birth weight 736 ± 157 g, gestational age 25.5 ± 1.5 weeks) received 322 transfusions from 47 PRBC units with 6.5 ± 3.5 different units used to complete all transfusions per infant. Lead was detected in all units. The average lead level in a PRBC unit was 18.3 ± 10.4 µg/L. Of 322 transfusions, 139 (43%) had lead volumes that exceeded the exposure reference. All infants received at least one transfusion with a lead volume exceeding the daily reference dose equivalent, and four infants (11%) received several transfusions with a cumulative lead volume exceeding the weekly reference dose. Blood transfusions are a potential source of lead for ELBW infants with unknown safety implications in this critical time of brain development.

Macroaggregates in the packed red blood cell unit during transfusion

Macroaggregates in the packed red blood cell unit during transfusion

Effect of leukoreduction treatment on vascular endothelial growth factor concentration in stored canine blood transfusion products

To evaluate vascular endothelial growth factor (VEGF) concentrations in canine blood products treated with or without a leukoreduction filter. 10 canine blood donors. Dogs underwent blood collection. Five of 10 units were leukoreduced prior to separation into packed RBCs and fresh frozen plasma (FFP). Concentrations of VEGF were measured by ELISA in plasma supernatants from aliquots of packed RBCs obtained immediately after separation and on days 7, 14, and 21 of storage. Fresh frozen plasma samples of 2 filtered and 2 nonfiltered units were examined after storage. RBC counts in whole blood before and after leukoreduction did not differ significantly, but WBCs and platelets were removed effectively. The VEGF concentration was lower than the detection limit (9 pg/mL) in 9 of 10 plasma samples and in all packed RBC and FFP units immediately after separation. The median VEGF concentrations in 5 nonfiltered packed RBC units were 37, 164, and 110 pg/mL on days 7, 14, and 21 of storage, respectively. In 5 filtered packed RBC and all FFP units, VEGF concentrations remained lower than the detection limit. Leukoreduction filters were effective in preventing the release of VEGF during storage of canine RBC products.

The Influence of the Duration of Storage of Red Blood Cells On Cancer Survival

AbstractAbstract 1184 Background:The duration of storage of red blood cells (RBC) has been associated with poor clinical outcomes amongst those receiving red cells. Patients with cancer are at risk of RBC transfusions and the effect of RBC storage is unknown in this population. We investigated the influence of duration of storage of RBC units transfused on overall survival (OS) and cancer recurrence in patients diagnosed with a new malignancy. We further described the transfusion requirements in this cohort of patients. Methods:Patients diagnosed with cancer at The Ottawa Regional Cancer Centre between January 01, 2000 and December 31, 2005 were included. Data was retrieved from the Ottawa Hospital Transfusion and Cancer database for analysis. RBC units were categorized as “new” if stored for less than 14 days, “intermediate” if stored between 14 to 28 days and “old” if stored for more than 28 days. Baseline characteristics between the comparative groups were compared by ANOVA test. Categorical variables and continuous variables were compared using Chi-squared and Wilcoxan rank-sum tests respectively. Kaplan-Meier analyses were used to examine differences in unadjusted survival while Cox-regression analyses were applied to adjust for potential confounding variables. Results:There were n=27,591 patients diagnosed with any cancer. The mean number of packed RBC units transfused was 3.42 (0.22, 6.62) with 1,929 (7.0%) patients receiving RBC within 1 year of diagnosis. Of these patients, 1335 (69.2%) received exclusively one “aged” category of RBC. The median OS was worse for patients who were transfused versus those not transfused (1.1 vs 7.5 years respectively, p<0.0001) as well as the number of RBC transfused (median OS for 1–2 units was 1.2 years, 3–5 units was 1.05 years and 6 or more units was 1.1 years; p=0.0017) in univariate analysis. Overall survival was not associated with duration of storage of transfused RBC with a median survival of 1.2, 1.7, 1.1 years for only new, intermediate and old RBC units respectively (p=0.36). Cancer recurrence was significantly higher in patients who received a RBC transfusion than those who did not (56.3% vs 33.0% respectively; p<0.0001) but was not affected by the duration of storage of transfused RBC (p=0.06). In multivariate analysis, a diagnosis of lung cancer, chemotherapy use, radiation use, cancer-related surgery and cancer recurrence were associated with inferior overall survival (p<0.05). In contrast, neither the number of RBC units transfused nor the duration of RBC storage before transfusion were associated with OS in multivariate analysis. Conclusion:In patients diagnosed with cancer, the duration of storage of transfused RBC had no impact on OS or cancer recurrence. However, the number of RBC transfused was associated with an increased risk for cancer recurrence. This suggests that current RBC storage policies are adequate for patients with malignancy requiring RBC transfusions. Disclosures:No relevant conflicts of interest to declare.

34. The effects of biochemical rejuvenation on red blood cell microvesiculation, phosphatidylserine and CD47 expression during hypothermic storage

Red blood cells (RBCs) under blood bank storage conditions undergo biophysical and biochemical alterations, including biochemical depletion of adenosine triphosphate (ATP) and 2,3-diphosphoglycerate (2,3-DPG), as well as cholesterol and phospholipid loss through microvesiculation. Microvesiculation is the process by which microparticles (MPs), phospholipid vesicles that are less than 1 μm in diameter, are released in response to different stimuli and conditions. RBC microparticles (RMPs) have been shown to be harmful effectors of inflammation and coagulation post transfusion, as well as in vitro indicators of RBC function and viability throughout ex vivo storage. Recent studies suggested that microvesiculation during storage results from biochemical depletion and/or cell senescence (Chernitskii˘ et al. 38 (8) (1993)18–21). Rejuvenation solutions have been shown to be able to restore ATP and 2,3-DPG levels in hypothermically stored RBCs. The purpose of this study was to examine the effects of the biochemical rejuvenation on red blood cell microvesiculation, as well as phosphatidylserine (PS) and CD47 expression during hypothermic storage. Leukoreduced packed RBC units (n = 14) were produced using the standard buffy coat method from whole blood in citrate–phosphate–dextrose (CPD) and stored in saline–adenine–glucose–mannitol (SAGM) at 1–6 °C for up to 49 days. Units were divided into three different experimental groups: untreated control, sham control and rejuvenated group. On days 28, 35, and 42 of hypothermic storage the rejuvenated group was incubated for one hour with 50 mL of rejuvenation solution containing pyruvate, inosine, phosphate and adenine (PIPA), while the sham control group was incubated for 1 h with 50 mL of 1× phosphate buffered saline. RBC units were tested weekly for ATP concentration, quantity of RMPs, and PS and CD47 expression. Microvesiculation was assessed using multicolor flow cytometric (FC) analysis and a spectrophotometric assay was used to determine ATP concentration. The results indicated that ATP significantly decreased throughout the hypothermic storage in untreated and sham RBC units (p

Results from a 1-year, open-label, single arm, multi-center trial evaluating the efficacy and safety of oral Deferasirox in patients diagnosed with low and int-1 risk myelodysplastic syndrome (MDS) and transfusion-dependent iron overload

The majority of patients with myelodysplastic syndrome (MDS) present with anemia and will become dependent on regular transfusions of packed red blood cells (PRBC) with the risk of iron overload (IOL). Liver iron content best reflects the total body iron content, and measurement of liver iron concentration (LIC) by MRI is a validated tool for detection, but data in MDS is rather limited. Here we present the results of a multi-center trial evaluating the efficacy and safety of deferasirox (DFX) in low and intermediate-1 risk MDS patients with transfusion-dependent IOL. Three patients with transfusion frequency of > 4 units PRBC per month were initially treated with 30mg/kg/day while in 46 patients with a lower transfusion burden deferasirox was initiated at 20mg/kg/day, due to patient related reasons one patient received DFX in a dose of 6mg/kg/day only. LIC was measured by MRI at baseline and end of study using the method by St. Pierre et al. The intention to treat population consisted of 50 MDS patients (28 male; 22 female) with a median age of 69years who were treated with DFX for a median duration of 354days. Mean daily dose of DFX was 19mg/kg/day. Median serum ferritin level (SF) at baseline was 2,447ng/mL and decreased to 1,685ng/mL (reduction by 31%) at end of study (p = 0.01). In 7 (13%) patients the initially chosen dose had to be increased due to unsatisfactory efficacy of chelation therapy. For 21 patients, LIC measurement by liver MRI was performed at baseline and for 19 of these patients at the end of study: mean LIC decreased significantly from 16,8mg/g dry tissue weight (± 8.3mg/g dry tissue weight) at study entry to 10,8mg/g dry tissue weight (± 10.4mg/g dry tissue weight) at end of study (p = 0.01). Of all patients exposed to the study drug (n = 54), 28 (52%) did not complete the 12month study period most commonly due to AEs in 28% (n = 15) and abnormal laboratory values in 7% (n = 4), respectively. The most common adverse events (≥ 10% of all patients) with suspected drug relationship were diarrhea (n = 25, 46%), nausea (n = 13, 24%), upper abdominal pain (n = 8, 15%), serum creatinine increase (n = 16, 30%) and rash (n = 5, 9%). Adverse events making dose adjustments or interruption of study drug necessary occurred in 33 patients (61%). Hematologic improvement according to IWG criteria (2006) was observed in 6 patients (11%). Initiation of treatment of IOL with DFX depending on the transfusion burden yields sufficient reduction of excess iron indicated by serum ferritin levels and most importantly by liver MRI. The safety profile of DFX was comparable to previous observations.

High dose of human plasma‐derived FVIII‐VWF as first‐line therapy in patients affected by acquired haemophilia A and concomitant cardiovascular disease: four case reports and a literature review

Haemostatic control is the first priority in acquired haemophilia A (AHA) and recent consensus recommendations suggest using bypassing agents (BAs) (recombinant activated FVII (rFVIIa) and activated prothrombin complex concentrate) as first-line treatment of bleeds. FVIII concentrates, both plasma-derived and recombinant, may be used with low inhibitor titre, minor haemorrhagic episodes and when bypassing drugs are not available [1]. The use of BAs may be associated with thrombotic complications, especially in the elderly with cardiovascular comorbidity, and should be carried out cautiously, as a literature review reported that 7% of patients treated with rFVIIa experienced thrombotic events [2]. Efficacy of FVIII concentrates in AHA has been reported since the early 1990s. Yet the published reports are retrospective, include few patients and deal with heterogeneous populations (see Table 1). Two main protocols have been recorded in the literature [3,4], but FVIII is often used at a much lower dosage. For instance, the data provided by the EACH2 Registry [5] reporting that the efficacy of FVIII treatment is lower than using BAs would show median doses inferior to those recommended in the literature (initial mean dose 50 U kg , total mean dose for patient 20 000 U, period-treatment range 4–6 days). This letter reports on the experience of our Centre in the use of high-dose human plasma-derived FVIII-VWF (HP-FVIII-VWF) concentrates in four patients affected by AHA and concomitant cardiovascular disease treated with a standardized protocol and include a review of the literature on the usage of HP-FVIII in the treatment of AHA.

The association of early transfusion with acute lung injury in patients with severe injury

Packed red blood cell (PRBC) transfusion is associated with acute lung injury (ALI) development after trauma, but this risk may not be constant through time after trauma. We hypothesized that the relationship between PRBC delivery and ALI risk varies through time after injury. Data were collected prospectively from 1999 to 2006. Inclusion criteria include the following: older than 13 years, surgical intensive care unit admission, and Injury Severity Score of 16 or greater. Exclusion criteria included discharge/death within 24 hours of admission. Patients were followed up prospectively for ALI development for 5 days after trauma. Discrete time models were fit to test the association of timing of PRBC delivery with the development of ALI while controlling for patient demographics, resuscitation variables, Injury Severity Score, and Acute Physiology and Chronic Health Evaluation III scores. At total of 602 patients were included. Median age was 33 years, 77% were male, and 50% were African American. Using a discrete time-survival model, the relation between transfusion and ALI development was found to vary by transfusion time window (p < 0.0001). The major effect of PRBC delivery on ALI risk occurred in the first 24 hours after trauma; this finding persisted in multivariable modeling (adjusted odds ratio, 1.07 per unit; 95% confidence interval, 1.02-1.11, p < 0.001). Cumulative incidence of ALI approached 50% in patients receiving 6 U of PRBC or more in the first 24 hours. The association between PRBC transfusion and ALI development in patients with trauma is time dependent, with PRBC delivery in the first 24 hours after injury driving the overall relation. Each PRBC unit during this period increases odds of subsequent ALI development by 7%. Prognostic/epidemiologic study, level II.

Bleeding from the Excluded Gastric Remnant after Roux-en-Y Gastric Bypass Controlled with Mesenteric Angiography

Introduction: We present a rare case of life threatening gastrointestinal bleeding from excluded gastroduodenal remnant after Roux-en-Y gastric bypass that was successfully controlled with mesenteric angiography and coil embolization of the proximal branch of the gastroduodenal artery (GDA). Case Report: A 43-year-old male with medical history of laparoscopic Rouxen-Y gastric bypass done for morbid obesity in 2006 presented with complaint of black tarry and maroon colored stools for one day prior to admission. He was using NSAIDs for chronic back pain. His vitals were stable at the time of admission. Patient was placed on proton pump inhibitor drip. Physical examination was significant for pallor and dark red blood on rectal examination. Initial laboratory data were significant for hemoglobin of 7.3gm/dl, Platelets of 167 K/μL and INR was 1.5. Patient was started on proton pump inhibitor drip and he was transfused initially with four units Packed Red Blood Cell (PRBC). Esophagogastroduodenoscopy (EGD) was performed and two small ulcers were found at the anastomotic site. Both of them had a clean base. One of the ulcers was deep linear ulcer with minimal oozing where epinephrine was injected and two hemoclips were placed with control of the oozing. Few hours later, patient developed hypovolemic shock after he had multiple episodes of hematemesis and maroon colored stools. He received an additional nine units of PRBCs and two units of fresh frozen plasma. Mesenteric angiogram was performed emergently as the severity of blood loss was unduly higher than the findings of EGD. It showed active bleeding from the proximal branch of GDA that was successfully embolized with two small micro-coils. Patient stabilized afterwards and he recovered. The GDA supplies the excluded gastroduodenal segment of the gastric bypass that was not visualized on EGD. Discussion: The incidence of bleeding after gastric bypass is estimated to be between 0.8 and 4.4%. Marginal ulcer is the most common cause of bleeding after gastric bypass. Bleeding from the excluded gastric remnant after Roux-en-Y gastric bypass is a rare event. Evaluation of the excluded gastric remnant is challenging and was limited to intraoperative gastrotomy and intraoperative endoscopy through the gastrotomy. Double balloon enteroscopy has been recently used to evaluate and control bleeding from excluded gastric remnant. We present a rare case in which mesenteric angiography was used to control bleeding from excluded gastric remnant that could be particularly useful especially in centers where double balloon enteroscopy is not readily available.

Altered thyroid function in severely injured patients

BackgroundHemorrhagic shock profoundly affects the neuroendocrine profile of trauma patients, and we hypothesized that massive resuscitation would negatively impact thyroid function. MethodsA prospective, observational study investigating thyroid function in hypotensive trauma patients (systolic blood pressure <90 mm Hg × 2) who survived >48 h was conducted at a Level I center over a 6-mo period. Blood samples for thyroid function were collected at time of presentation to the trauma bay and serially for 48 h. Collected data included demographics, injury data, vital signs, transfusion needs, crystalloid use, and vasopressor requirements. Patients receiving >5 units packed red blood cells (PRBC) within 12 h were compared with those receiving ≤5 units. ResultsPatients who required >5 units of PRBC/12 h had significantly lower total and free T4 levels on initial presentation, and levels remained significantly depressed over the next 48 h when compared with patients who required a less aggressive resuscitative effort. T3 values were markedly suppressed during the initial 48 h post trauma in all patients, but were significantly lower in patients requiring >5 units PRBC. TSH levels remained within the normal range for all time points. Lower trauma admission T4 levels were associated with the need for greater crystalloid resuscitation within the first 24 h. ConclusionMeasurements of thyroid function are significantly altered in severely injured patients on initial presentation, and low T4 levels predict the need for large resuscitation. Further research investigating the profile and impact of thyroid function in trauma patients during resuscitation and recovery is warranted.

How appropriately is blood ordered in a rural hospital?

BackgroundBlood products are a limited resource particularly in a rural setting and their appropriate use is important to maintain patient safety and minimise costs. ObjectiveTo assess the appropriateness of transfusion practices in a rural hospital. Design/Data SourcesA retrospective medical record audit of packed red blood cell (PRBC) use. SettingA rural hospital 300km northwest of Melbourne. ParticipantsAll patients in Wimmera Base Hospital who had a PRBC crossmatch request from October 2010 to March 2011 inclusive. Main outcome measuresProportion of appropriate transfusions and crossmatch to transfusion ratios. ResultsA total of 257 patients and 657 PRBC units were cross-matched during the study period. Of these patients, 28.4% had pre-procedure (elective) cross-matches. Of the elective cross-matches, 27.4% were inappropriate, compared with 16.1% of emergency cross-matches. The cross-match to transfusion ratio (C:T) was 1.59 for emergency requests and 5.96 for elective requests. The C:T ratio was high in the surgical and obstetrics and gynaecology departments. 16.3% of all transfusions were single-unit transfusions. ConclusionsEmergency requests were predominantly appropriate but a significant proportion of elective requests were inappropriate, suggesting changes in elective crossmatch request protocols, and increased education regarding ordering blood in a rural setting.

P-040 A comparison between particulate and Onyx embolization for devascularization of Juvenile angiofibromas prior to surgical resection

IntroductionJuvenile nasopharyngeal angiofibroma is a locally invasive tumor in adolescent males. Surgical resection is the treatment of choice, but the tumor's extensive vascular involvement necessitates preoperative embolization. In this retrospective...

A modelling approach for blood units transfused after stem cell transplantation

Patients undergoing stem cell transplantation may require transfusion of units (bags) of packed red blood cells (PRBCs). Modelling of PRBC usage is important not only for prediction of transfusion requirements in future patients but also for its use as an inverse surrogate for engraftment, that is transplantation success. Inspection of PRBC unit usage reveals a strong preference for even numbers, which is caused by behavioural preference on the part of prescribing physicians. Digit preference is a phenomenon observed more commonly with self-reported data: typically survey respondents round recalled quantities such as the age at which a life event occurred to multiples of 5 or 10. In all cases, we can conceive of a latent variable, which has a smooth distribution, which is transformed via stochastic rules to a discrete variable with probability spikes at preferred digits. We propose a modelling framework based on a latent variable specification and stochastic transformation to the spiked distribution. Loglinear models for the mean of the process are implemented. Specification of the stochastic rules is important to success in accurate modelling of the process.

The Oslo massacre 2011

Background In terrorist attacks on July 22, 2011, seventy‐seven people were killed; 8 in and around the goverment buildings in downtown Oslo due to a huge bomb explosion, and 69 mostly young people due to shootings at Utøya; an island outside Oslo where there was an ongoing political youth camp. Thirthy‐one heavily injured patients were admitted to the Oslo University Hospital, Ullevaal that houses the trauma referral centre, and all except for one patient survived.Aims This report presents how we handled the disaster at the Department of Immunology and Transfusion Medicine that hosts the Blood Bank of Oslo.Methods Being the largest blood bank in Norway, we are supposed to have a stock of approximately 1750 units of packed red blood cells (PRBC) of all blood types at any time including a stock of minimum 80, and rather 130 units of blood type O RhD negative PRBC. But instead we had only 55 O RhD negative units when the terrorist attacks started. Since this was too low, we had to collect blood from already registered blood donors at our blood bank, and at the same time purchase units from the other blood banks. We had yet called a couple of donors, then an enormous flow of people who wanted to donate blood started. There were hundreds of people, a lot of them not registered from before. Chaos lasted several hours until the security guards gained control over the situation.Results The Blood Bank was well‐staffed with 28 biomedical laboratory technicians, nurses and doctors both on July 22 and 23, and collected blood from 220 donors. We bought also 80 units of PRBC from the other blood banks. Sixty units of PRBC, 14 platelet concentrates and 51 units of plasma were issued on 22 and 23 July, and during the first five days 84, 14 and 61 units, respectively. One of the major challenges was, already in the beginning, to estimate the blood requirements to come without knowing the dimensions of the disaster. This was necessary in order to decide how many blood units to purchase from the other blood banks and to collect from registered donors. Over‐collection could lead to massive discards of non‐used units, waste of money/resources, harm blood donor recruitment later, and cause loss of trust in the transfusion service. Discards stayed at a very low level. However, we may have hindered chaos due to hundreds of people who wanted to donate blood if we, in a much earlier phase, had communicated with media and announced at the social platforms that only our registered donors with blood type O RhD negative were needed.Conclusion In a real emergency, only units that are ready to transfuse can be used in life‐saving treatment, because it takes several hours from the collection of blood until the unit is ready for transfusion. Therefore blood banks need a stable supply of donors to maintain an adequate stock of blood at any time.