Artificial intelligence model GPT4 narrowly fails simulated radiological protection exam.

This study assesses the efficacy of Generative Pre-Trained Transformers (GPT) published by OpenAI in the specialised domains of radiological protection and health physics. Utilising a set of 1064 surrogate questions designed to mimic a health physics certification exam, we evaluated the models' ability to accurately respond to questions across five knowledge domains. Our results indicated that neither model met the 67% passing threshold, with GPT-3.5 achieving a 45.3% weighted average and GPT-4 attaining 61.7%. Despite GPT-4's significant parameter increase and multimodal capabilities, it demonstrated superior performance in all categories yet still fell short of a passing score. The study's methodology involved a simple, standardised prompting strategy without employing prompt engineering or in-context learning, which are known to potentially enhance performance. The analysis revealed that GPT-3.5 formatted answers more correctly, despite GPT-4's higher overall accuracy. The findings suggest that while GPT-3.5 and GPT-4 show promise in handling domain-specific content, their application in the field of radiological protection should be approached with caution, emphasising the need for human oversight and verification.

Radioactive seed localization is a safe and effective tool for breast cancer surgery: an evaluation of over 25,000 cases.

Radioactive seed localization (RSL) provides a precise and efficient method for removing non-palpable breast lesions. It has proven to be a valuable addition to breast surgery, improving perioperative logistics and patient satisfaction. This retrospective review examines the lessons learned from a high-volume cancer center's RSL program after 10 years of practice and over 25 000 cases. We provide an updated model for assessing the patient's radiation dose from RSL seed implantation and demonstrate the safety of RSL to staff members. Additionally, we emphasize the importance of various aspects of presurgical evaluation, surgical techniques, post-surgical management, and regulatory compliance for a successful RSL program. Notably, the program has reduced radiation exposure for patients and medical staff.

Impact of shield location on staff and caregiver dose rates for I-131 radiopharmaceutical therapy patients.

The goal of this study is to investigate the effect of the location and width of a single lead shield on the dose rate of staff and caregivers in a hospital room with an I-131 patient. The best orientation of the patient and caregiver relative to the shield was determined based on minimizing staff and caregiver radiation dose rates. Shielded and unshielded dose rates were simulated using a Monte Carlo computer simulation and validated using real-world ionisation chamber measurements. Based on a radiation transport analysis using an adult voxel phantom published by the International Commission on Radiological Protection, placing the shield near the caregiver yielded the lowest dose rates. However, this strategy reduced the dose rate in only a tiny area of the room. Furthermore, positioning the shield near the patient in the caudal direction provided a modest dose rate reduction while shielding a large room area. Finally, increased shield width was associated with decreasing dose rates, but only a four-fold dose-rate reduction was observed for standard width shields. The recommendations of this case study may be considered as potential candidate room configurations where radiation dose rates are minimized, however these findings must be weighed against additional clinical, safety, and comfort considerations.

OCCUPATIONAL EYE LENS DOSE OVER SIX YEARS IN THE STAFF OF A US HIGH-VOLUME CANCER CENTER.

This paper summarizes the dose to the eye lens of workers of Memorial Sloan Kettering Cancer Center, a high-volume US oncologic and associated diseases facility. The doses presented in this report were collected from personal dosemeter readings using optically stimulated luminescence badges to estimate Hp(3). Doses were collected for 5950 clinical and research workers between January 2012 and December 2017. The median eye lens dose for all monitored workers was 0.23 mSv y-1. Workers performing, or supporting, fluoroscopy procedures received the highest unprotected eye lens dose of all workers with a median eye dose of 10 mSv. The use of leaded glasses by this group reduced the actual doses to the lens. Nurses and technicians involved in positron emission tomography injections received median eye lens dose of 1.2 mSv.

Anaesthesia, surgery, and life-threatening allergic reactions: protocol and methods of the 6th National Audit Project (NAP6) of the Royal College of Anaesthetists.

BACKGROUND: Anaphylaxis during anaesthesia is a serious complication for patients and anaesthetists. METHODS: The Sixth National Audit Project (NAP6) of the Royal College of Anaesthetists examined the incidence, predisposing factors, management, and impact of life-threatening perioperative anaphylaxis in the UK. NAP6 included: a national survey of anaesthetists' experiences and perceptions; a national survey of allergy clinics; a registry collecting detailed reports of all Grade 3-5 perioperative anaphylaxis cases for 1 yr; and a national survey of anaesthetic workload and perioperative allergen exposure. NHS and independent sector (IS) hospitals were approached to participate. Cases were reviewed by a multi-disciplinary expert panel (anaesthetists, intensivists, allergists, immunologists, patient representatives, and stakeholders) using a structured process designed to minimise bias. Clinical management and investigation were compared with published guidelines. This paper describes detailed study methods and reports on project engagement by NHS and IS hospitals. The methodology includes a new classification of perioperative anaphylaxis and a new structured method for classifying suspected anaphylactic events including the degree of certainty with which a causal trigger agent can be attributed. RESULTS: NHS engagement was complete (100% of hospitals). Independent sector engagement was limited (13% of approached hospitals). We received >500 reports of Grade 3-5 perioperative anaphylaxis, with 266 suitable for analysis. We identified 199 definite or probable culprit agents in 192 cases. CONCLUSIONS: The methods of NAP6 were robust in identifying causative agents of anaphylaxis, and support the accompanying analytical papers.

Anaesthesia, surgery, and life-threatening allergic reactions: epidemiology and clinical features of perioperative anaphylaxis in the 6th National Audit Project (NAP6).

BACKGROUND: Anaphylaxis during anaesthesia is a serious complication for patients and anaesthetists. METHODS: The 6th National Audit Project (NAP6) on perioperative anaphylaxis collected and reviewed 266 reports of Grades 3-5 anaphylaxis over 1 yr from all NHS hospitals in the UK. RESULTS: The estimated incidence was ≈1:10 000 anaesthetics. Case exclusion because of reporting delays or incomplete data means true incidence might be ≈70% higher. The distribution of 199 identified culprit agents included antibiotics (94), neuromuscular blocking agents (65), chlorhexidine (18), and Patent Blue dye (9). Teicoplanin comprised 12% of antibiotic exposures, but caused 38% of antibiotic-induced anaphylaxis. Eighteen patients reacted to an antibiotic test dose. Succinylcholine-induced anaphylaxis, mainly presenting with bronchospasm, was two-fold more likely than other neuromuscular blocking agents. Atracurium-induced anaphylaxis mainly presented with hypotension. Non-depolarising neuromuscular blocking agents had similar incidences to each other. There were no reports of local anaesthetic or latex-induced anaphylaxis. The commonest presenting features were hypotension (46%), bronchospasm (18%), tachycardia (9.8%), oxygen desaturation (4.7%), bradycardia (3%), and reduced/absent capnography trace (2.3%). All patients were hypotensive during the episode. Onset was rapid for neuromuscular blocking agents and antibiotics, but delayed with chlorhexidine and Patent Blue dye. There were 10 deaths and 40 cardiac arrests. Pulseless electrical activity was the usual type of cardiac arrest, often with bradycardia. Poor outcomes were associated with increased ASA, obesity, beta blocker, and angiotensin-converting enzyme inhibitor medication. Seventy per cent of cases were reported to the hospital incident reporting system, and only 24% to Medicines and Healthcare products Regulatory Agency via the Yellow Card Scheme. CONCLUSIONS: The overall incidence of perioperative anaphylaxis was estimated to be 1 in 10 000 anaesthetics.

Cross-sectional study of perioperative drug and allergen exposure in UK practice in 2016: the 6th National Audit Project (NAP6) Allergen Survey.

BACKGROUND: Details of the current UK drug and allergen exposure were needed for interpretation of reports of perioperative anaphylaxis to the 6th National Audit Project (NAP6). METHODS: We performed a cross-sectional survey of 356 NHS hospitals determining anaesthetic drug usage in October 2016. All cases cared for by an anaesthetist were included. RESULTS: Responses were received from 342 (96%) hospitals. Within-hospital return rates were 96%. We collected 15 942 forms, equating to an annual caseload of 3.1 million, including 2.4 million general anaesthetics. Propofol was used in 74% of all cases and 90% of general anaesthetics. Maintenance included a volatile agent in 95% and propofol in 8.7%. Neuromuscular blocking agents were used in 47% of general anaesthetics. Analgesics were used in 88% of cases: opioids, 82%; paracetamol, 56%; and non-steroidal anti-inflammatory drugs, 28%. Antibiotics were administered in 57% of cases, including 2.5 million annual perioperative administrations; gentamicin, co-amoxiclav, and cefuroxime were most commonly used. Local anaesthetics were used in 74% cases and 70% of general anaesthetics. Anti-emetics were used in 73% of cases: during general anaesthesia, ondansetron in 78% and dexamethasone in 60%. Blood products were used in ≈3% of cases, gelatin <2%, starch very rarely, and tranexamic acid in ≈6%. Chlorhexidine and povidone-iodine exposures were 74% and 40% of cases, and 21% reported a latex-free environment. Exposures to bone cement, blue dyes, and radiographic contrast dye were each reported in 2-3% of cases. CONCLUSIONS: This survey provides insights into allergen exposures in perioperative care, which is important as denominator data for the NAP6 registry.

Anaesthesia, surgery, and life-threatening allergic reactions: management and outcomes in the 6th National Audit Project (NAP6).

BACKGROUND: Anaphylaxis during anaesthesia is a serious complication for patients and anaesthetists. There is little published information on management and outcomes of perioperative anaphylaxis in the UK. METHODS: The 6th National Audit Project of the Royal College of Anaesthetists (NAP6) collected and reviewed 266 reports of Grade 3-5 anaphylaxis from all UK NHS hospitals over 1 yr. Quality of management was assessed against published guidelines. RESULTS: Appropriately senior anaesthetists resuscitated all patients. Immediate management was 'good' in 46% and 'poor' in 15%. Recognition and treatment of anaphylaxis were prompt in 97% and 83% of cases, respectively. Epinephrine was administered i.v. in 76%, i.m. in 14%, both in 6%, and not at all in 11% of cases. A catecholamine infusion was administered in half of cases. Cardiac arrests (40 cases; 15%) were promptly treated but cardiac compressions were omitted in half of patients with unrecordable BP. The surgical procedure was abandoned in most cases, including 10% where surgery was urgent. Of 54% admitted to critical care, 70% were level 3, with most requiring catecholamine infusions. Ten (3.8%) patents (mostly elderly with cardiovascular disease) died from anaphylaxis. Corticosteroids and antihistamines were generally administered early. We found no clear evidence of harm or benefit from chlorphenamine. Two patients received vasopressin and one glucagon. Fluid administration was inadequate in 19% of cases. Treatment included sugammadex in 19 cases, including one when rocuronium had not been administered. Adverse sequelae (psychological, cognitive, or physical) were reported in one-third of cases. CONCLUSIONS: Management of perioperative anaphylaxis could be improved, especially with respect to administration of epinephrine, cardiac compressions, and i.v. fluid. Sequelae were common.

An observational national study of anaesthetic workload and seniority across the working week and weekend in the UK in 2016: the 6th National Audit Project (NAP6) Activity Survey.

BACKGROUND: UK national anaesthetic activity was studied in 2013 but weekend working was not examined. Understanding changes since 2013 in workload and manpower distribution, including weekends, would be of value in workforce planning. METHODS: We performed an observational survey of NHS hospitals' anaesthetic practice in October 2016 as part of the 6th National Audit Project of the Royal College of Anaesthetists (NAP6). All cases cared for by an anaesthetist during the study period were included. Patient characteristics and details of anaesthetic conduct were collected by local anaesthetists. RESULTS: Responses were received from 342/356 (96%) hospitals. In total, 15 942 cases were reported, equating to an annual anaesthetic workload of ≈3.13 million cases. Approximately 95% (9888/10 452) of elective and 72% (3184/4392) of emergency work was performed on weekdays and 89% (14 145/15 942) of activity was led by senior (consultant or career grade) anaesthetists and 1.1% (180/15942) by those with <2 yr anaesthetic experience. During weekends case urgency increased, the proportion of healthy patients reduced and case mix changed. Cases led by senior anaesthetists fell to 80% (947/1177) on Saturday and 66% (342/791) on Sunday. Senior involvement in obstetric anaesthetic activity was 69% (628/911) during the week and 45% (182/402) at weekends, compared with 93% (791/847) in emergency orthopaedic procedures during the week and 89% (285/321) at weekends. Since 2013, the proportion of obese patients, elective weekend working, and depth of anaesthesia monitoring has increased [12% (1464/12 213) vs 2.8%], but neuromuscular monitoring has not [37% (2032/5532) vs 38% of paralysed cases]. CONCLUSIONS: Senior clinicians deliver most UK anaesthesia care, including at weekends. Our findings are important for any planned workforce reorganisation to rationalise 7-day working.

Specialist perioperative allergy clinic services in the UK 2018: Results from the Royal College of Anaesthetists Sixth National Audit Project (NAP6) investigation of perioperative anaphylaxis.

BACKGROUND: The Royal College of Anaesthetists 6th National Audit Project examined Grade 3-5 perioperative anaphylaxis for 1 year in the UK. OBJECTIVE: To describe the causes and investigation of anaphylaxis in the NAP6 cohort, in relation to published guidance and previous baseline survey results. METHODS: We used a secure registry to gather details of Grade 3-5 perioperative anaphylaxis. Anonymous reports were aggregated for analysis and reviewed in detail. Panel consensus diagnosis, reaction grade, review of investigations and clinic assessment are reported and compared to the prior NAP6 baseline clinic survey. RESULTS: A total of 266 cases met inclusion criteria between November 2015 and 2016, detailing reactions and investigations. One hundred and ninety-two of 266 (72%) had anaphylaxis with a trigger identified, of which 140/192 (75%) met NAP6 criteria for IgE-mediated allergic anaphylaxis, 13% lacking evidence of positive IgE tests were labelled "non-allergic anaphylaxis". 3% were non-IgE-mediated anaphylaxis. Adherence to guidance was similar to the baseline survey for waiting time for clinic assessment. However, lack of testing for chlorhexidine and latex, non-harmonized testing practices and poor coverage of all possible culprits was confirmed. Challenge testing may be underused and many have unacceptably delayed assessments, even in urgent cases. Communication or information provision for patients was insufficient, especially for avoidance advice and communication of test results. Insufficient detail regarding skin test methods was available to draw conclusions regarding techniques. CONCLUSION AND CLINICAL RELEVANCE: Current clinical assessment in the UK is effective but harmonization of approach to testing, access to services and MHRA reporting is needed. Expert anaesthetist involvement should increase to optimize diagnostic yield and advice for future anaesthesia. Dynamic tryptase evaluation improves detection of tryptase release where peak tryptase is <14 µg/L and should be adopted. Standardized clinic reports containing appropriate details of tests, conclusions, avoidance, cross-reactivity and suitable alternatives are required to ensure effective, safe future management options.

Effective dose rate coefficients for exposure to contaminated soil.

The Oak Ridge National Laboratory Center for Radiation Protection Knowledge has undertaken calculations related to various environmental exposure scenarios. A previous paper reported the results for submersion in radioactive air and immersion in water using age-specific mathematical phantoms. This paper presents age-specific effective dose rate coefficients derived using stylized mathematical phantoms for exposure to contaminated soils. Dose rate coefficients for photon, electron, and positrons of discrete energies were calculated and folded with emissions of 1252 radionuclides addressed in ICRP Publication 107 to determine equivalent and effective dose rate coefficients. The MCNP6 radiation transport code was used for organ dose rate calculations for photons and the contribution of electrons to skin dose rate was derived using point-kernels. Bremsstrahlung and annihilation photons of positron emission were evaluated as discrete photons. The coefficients calculated in this work compare favorably to those reported in the US Federal Guidance Report 12 as well as by other authors who employed voxel phantoms for similar exposure scenarios.

Effective Dose Rate Coefficients for Immersions in Radioactive Air and Water.

The Oak Ridge National Laboratory Center for Radiation Protection Knowledge (CRPK) has undertaken a number of calculations in support of a revision to the United States Environmental Protection Agency (US EPA) Federal Guidance Report on external exposure to radionuclides in air, water and soil (FGR 12). Age-specific mathematical phantom calculations were performed for the conditions of submersion in radioactive air and immersion in water. Dose rate coefficients were calculated for discrete photon and electron energies and folded with emissions from 1252 radionuclides using ICRP Publication 107 decay data to determine equivalent and effective dose rate coefficients. The coefficients calculated in this work compare favorably to those reported in FGR12 as well as by other authors that employed voxel phantoms for similar exposure scenarios.

Reducing Statistical Uncertainties in Simulated Organ Doses of Phantoms Immersed in Water.

In this article, methods are addressed to reduce the computational time to compute organ-dose rate coefficients using Monte Carlo techniques. Several variance reduction techniques are compared including the reciprocity method, importance sampling, weight windows and the use of the ADVANTG software package. For low-energy photons, the runtime was reduced by a factor of 105 when using the reciprocity method for kerma computation for immersion of a phantom in contaminated water. This is particularly significant since impractically long simulation times are required to achieve reasonable statistical uncertainties in organ dose for low-energy photons in this source medium and geometry. Although the MCNP Monte Carlo code is used in this paper, the reciprocity technique can be used equally well with other Monte Carlo codes.

COMPARISON OF MONOENERGETIC PHOTON ORGAN DOSE RATE COEFFICIENTS FOR STYLIZED AND VOXEL PHANTOMS SUBMERGED IN AIR.

As part of a broader effort to calculate effective dose rate coefficients for external exposure to photons and electrons emitted by radionuclides distributed in air, soil or water, age-specific stylized phantoms have been employed to determine dose coefficients relating dose rate to organs and tissues in the body. In this article, dose rate coefficients computed using the International Commission on Radiological Protection reference adult male voxel phantom are compared with values computed using the Oak Ridge National Laboratory adult male stylized phantom in an air submersion exposure geometry. Monte Carlo calculations for both phantoms were performed for monoenergetic source photons in the range of 30 keV to 5 MeV. These calculations largely result in differences under 10 % for photon energies above 50 keV, and it can be expected that both models show comparable results for the environmental sources of radionuclides.

Estimated dose rates to members of the public from external exposure to patients with 131I thyroid treatment.

PURPOSE: Estimated dose rates that may result from exposure to patients who had been administered iodine-131 ((131)I) as part of medical therapy were calculated. These effective dose rate estimates were compared with simplified assumptions under United States Nuclear Regulatory Commission Regulatory Guide 8.39, which does not consider body tissue attenuation nor time-dependent redistribution and excretion of the administered (131)I. METHODS: Dose rates were estimated for members of the public potentially exposed to external irradiation from patients recently treated with (131)I. Tissue attenuation and iodine biokinetics were considered in the patient in a larger comprehensive effort to improve external dose rate estimates. The external dose rate estimates are based on Monte Carlo simulations using the Phantom with Movable Arms and Legs (PIMAL), previously developed by Oak Ridge National Laboratory and the United States Nuclear Regulatory Commission. PIMAL was employed to model the relative positions of the (131)I patient and members of the public in three exposure scenarios: (1) traveling on a bus in a total of six seated or standing permutations, (2) two nursing home cases where a caregiver is seated at 30 cm from the patient's bedside and a nursing home resident seated 250 cm away from the patient in an adjacent bed, and (3) two hotel cases where the patient and a guest are in adjacent rooms with beds on opposite sides of the common wall, with the patient and guest both in bed and either seated back-to-back or lying head to head. The biokinetic model predictions of the retention and distribution of (131)I in the patient assumed a single voiding of urinary bladder contents that occurred during the trip at 2, 4, or 8 h after (131)I administration for the public transportation cases, continuous first-order voiding for the nursing home cases, and regular periodic voiding at 4, 8, or 12 h after administration for the hotel room cases. Organ specific activities of (131)I in the thyroid, bladder, and combined remaining tissues were calculated as a function of time after administration. Exposures to members of the public were considered for (131)I patients with normal thyroid uptake (peak thyroid uptake of ∼27% of administered (131)I), differentiated thyroid cancer (DTC, 5% uptake), and hyperthyroidism (80% uptake). RESULTS: The scenario with the patient seated behind the member of the public yielded the highest dose rate estimate of seated public transportation exposure cases. The dose rate to the adjacent room guest was highest for the exposure scenario in which the hotel guest and patient are seated by a factor of ∼4 for the normal and differentiated thyroid cancer uptake cases and by a factor of ∼3 for the hyperthyroid case. CONCLUSIONS: It was determined that for all modeled cases, the DTC case yielded the lowest external dose rates, whereas the hyperthyroid case yielded the highest dose rates. In estimating external dose to members of the public from patients with (131)I therapy, consideration must be given to (patient- and case-specific) administered (131)I activities and duration of exposure for a more complete estimate. The method implemented here included a detailed calculation model, which provides a means to determine dose rate estimates for a range of scenarios. The method was demonstrated for variations of three scenarios, showing how dose rates are expected to vary with uptake, voiding pattern, and patient location.

An empirical method for deriving RBE values associated with electrons, photons and radionuclides.

There is substantial evidence to justify using relative biological effectiveness (RBE) values of >1 for low-energy electrons and photons. But, in the field of radiation protection, radiation associated with low linear energy transfer has been assigned a radiation weighting factor wR of 1. This value may be suitable for radiation protection but, for risk considerations, it is important to evaluate the potential elevated biological effectiveness of radiation to improve the quality of risk estimates. RBE values between 2 and 3 for tritium are implied by several experimental measurements. Additionally, elevated RBE values have been found for other similar low-energy radiation sources. In this work, RBE values are derived for electrons based upon the fractional deposition of absorbed dose of energies less than a few kiloelectron volts. Using this empirical method, RBE values were also derived for monoenergetic photons and 1070 radionuclides from ICRP Publication 107 for which photons and electrons are the primary emissions.

Dose conversion coefficients for neutron exposure to the lens of the human eye.

Dose conversion coefficients for the lens of the human eye have been calculated for neutron exposure at energies from 1 × 10(-9) to 20 MeV and several standard orientations: anterior-to-posterior, rotational and right lateral. MCNPX version 2.6.0, a Monte Carlo-based particle transport package, was used to determine the energy deposited in the lens of the eye. The human eyeball model was updated by partitioning the lens into sensitive and insensitive volumes as the anterior portion (sensitive volume) of the lens being more radiosensitive and prone to cataract formation. The updated eye model was used with the adult UF-ORNL mathematical phantom in the MCNPX transport calculations.

Epidural analgesia and liver resection: postoperative coagulation disorders and epidural catheter removal.

BACKGROUND: The aim of this study was to quantify the duration and severity of postoperative coagulopathy in order to establish the optimal time for epidural catheter removal. METHODS: In a 2-year retrospective study, 140 consecutive patients underwent major liver resection. RESULTS: Epidural catheters were present in 123 patients (87.9%). Resections were: 33 (26.8%) right hepatectomy (with or without left metastasectomy), 9 (7.3%) left hemihepatectomy (with or without right metastasectomy), 37 (30.1%) trisectionectomy (extended hemihepatectomy) and 44 (35.8%) non-anatomical metastasectomy. Surgery was quantified by segments resected (4 [range: 1-7]). Vascular inflow occlusion was used in 65.6%. Ischaemic time was 26.5 min (range: 0-104 min). Platelet count fell postoperatively and was lowest on day 2 (205±72 10(9) L(-1)). There was a significant increase in prothrombin time, activated partial thromboplastin time and International Normalised Ratio (INR) postoperatively, peaking on day 2 (21.5±5.6 s, 37.9±5.8 s and 1.9±0.5, respectively). Changes persisted beyond day 6. Epidural catheters were removed on day 5 (1-11), with a protocol criterion of INR <1.2. Actual INR on day 5 was 1.49±0.36. CONCLUSION: Despite this, no epidural or spinal haematoma was recorded.

Massive transfusion--evaluation of current clinical practice and outcome in two large teaching hospital trusts in Northern England.

BACKGROUND AND OBJECTIVES: Although numerous guidelines exist for the management of massive blood loss, there have been few data confirming whether these guidelines are observed in practice or whether compliance results in improved outcome. We have performed a retrospective audit of cases of massive transfusion in two major teaching hospital trusts in Northern England to investigate the use of blood components and patient outcome. MATERIALS AND METHODS: The massive transfusion population was electronically derived from a list of all blood component transfusions in 2006. Data from the intensive care and patient administration databases established hospital outcome. Factors independently predictive of survival were identified by logistic regression. Data are presented as medians and interquartile ranges. Odds ratios (OR) are given with 95% confidence intervals. RESULTS: Two hundred and four patients had a massive transfusion. Although only 1.3% of all transfused patients, the massive transfusion group used 10% of the total blood products. Their mortality rate was 34%. Factors independently predictive of survival were: a ratio of fresh frozen plasma: red blood cells > 1.1, OR 7.22 (1.95-26.68), and elective surgery, OR 4.56 (1.88-11.05). Factors independently predictive of death were: age (per year), OR 0.97 (0.95-0.99), liver disease, OR 0.25 (0.09-0.70), male gender, OR 0.41 (0.19-0.89), vascular surgery, OR 0.34 (0.12-0.96) and number of adult packs of platelets transfused, OR 0.69 (0.57-0.83). CONCLUSION: Massive transfusion occurs rarely but has a high mortality and requires a disproportionate amount of blood products. An increased ratio of fresh frozen plasma to red blood cells was associated with improved outcome.