Performance assessment of intravenous catheters for massive transfusion: A pragmatic in vitro study.

BACKGROUND: Rapid infusion of warmed blood products is the cornerstone of trauma resuscitation and treatment of surgical and obstetric massive hemorrhage. Integral to optimizing this delivery is selection of an intravenous (IV) catheter and use of a rapid infusion device (RID). We investigated which IV catheter and RID system enabled the greatest infusion rate of blood products and the governing catheter characteristics. STUDY DESIGN AND METHODS: The maximum flow rates of nine IV catheters were measured while infusing a mixture of packed red blood cells and fresh frozen plasma at a 1:1 ratio using a RID with and without a patient line extension. To account for IV catheters that achieved the RID's maximum 1000 ml/min, the conductance of each infusion circuit configuration was calculated. RESULTS: IV catheters of 7-Fr caliber or higher reached the maximum pressurized flow rate. The 9-Fr multi-lumen access catheter (MAC) achieved the greatest conductance, over sevenfold greater than the 18 g peripheral catheter (4.6 vs. 0.6 ml/min/mmHg, p < .001). Conductance was positively correlated with internal radius (ß = 1.098, 95% CI 4.286-5.025, p < .001) and negatively correlated with length (ß= - 0.495, 95% CI -0.007 to 0.005, p < .001). Use of an extension line (ß= - 0.094, 95% CI -0.505 to -0.095, p = .005) was independently associated with reduced conductance in large caliber catheters. CONCLUSION: Short, large-diameter catheters provided the greatest infusion rates of massive transfusion blood products for the least pressure. For patients requiring the highest transfusion flow rates, extension tubing should be avoided when possible.

Hemodiafiltration-A Technique for Physiological Correction of Priming Solution in Pediatric Cardiac Surgery: An In Vitro Study.

Pediatric cardiopulmonary bypass (CPB) circuit invariably requires priming with packed red blood cells (PRBCs). Metabolic composition of stored PRBCs is unphysiological and becomes worse with increasing duration of storage. It is recommended to correct these abnormalities before initiation of CPB. We tested the hypothesis that hemodiafiltration of the prime with 0.45% saline is sufficient for reducing the metabolic load and reaching a physiologic state. In an in vitro study, 100 mL of blood each from 45 units of PRBCs stored for 3-20 days were used for priming the 45 neonatal CPB circuits. Based upon the method used for removal of excess crystalloid from the prime, circuits were divided into three groups. Group 1: Direct removal through manifold line. Group 2: Ultrafiltration of prime. Group 3: Hemodiafiltration of the prime. Blood gas analyses were obtained from the PRBCs and from the prime before and after removal of crystalloid. Both direct removal of crystalloid and ultrafiltration resulted in significant reduction in biochemical and metabolic load of blood (P < 0.001). However, the final composition of the prime was far from being physiological. Hemodiafiltration resulted in improvement of metabolic parameters to near physiological range (lactate: 33.8 ± 4.44 vs. 14 ± 2.53 mg/dL, pH: 7.05 ± 0.15 vs. 7.34 ± 0.06, bicarbonates: 4.83 ± 0.59 vs. 27.6 ± 2.94 meq/L; P < 0.001). Similarly, sodium (147.76 ± 12.73 vs. 144.6 ± 5.96 meq/L) and potassium (9.6 ± 2.83 vs. 4.23 ± 0.37 meq/L) also changed significantly (P < 0.001) to near physiologic range. Hemodiafiltraion of final prime is a simple, efficients and rapid method of correcting the biochemical parameters and reducing the metabolic load of stored PRBCs towards the physiological range before initiating the CPB.

Comparative evaluation of the depletion-red cell exchange program with the Spectra Optia and the isovolemic hemodilution-red cell exchange method with the COBE Spectra in sickle cell disease patients.

BACKGROUND: This study aims to compare in patients with sickle cell disease (SCD), the technical performance and packed red blood cell unit consumption between the automated depletion/Red Blood Cell exchange (RBCx) program (Spectra Optia Apheresis System) with the isovolemic hemodilution (IHD)/RBCx procedure (COBE Spectra Apheresis System) in a routine clinical setting. METHODS: We retrospectively reviewed the data of 23 patients treated between October 2010 and August 2013 who underwent repeated RBCx on both apheresis systems for preventive indications. Each patient was their own control and had undergone two procedures on each system, totaling 46 sessions per group. On Spectra Optia, we performed the automated depletion/RBCx program. For COBE Spectra, we used a modified IHD/RBCx protocol. All patients had an initial 250 mL depletion offset by a 5% albumin prior to the exchange procedure, for the respective device, with leucodepleted Rh/Kell compatible and cross-matched RBC packs. RESULTS: All procedures were well tolerated except three mild febrile nonhemolytic reactions. Postprocedure hemoglobin S (HbS), fraction of cells remaining (FCR), procedure duration and processed blood and anticoagulant volumes were comparable in the two groups. However, the RBCx volume was significantly higher for the Spectra Optia group (+71 mL, P = 0.01), with no significant difference in the number of RBC units used. CONCLUSIONS: Technical performance and packed RBC unit consumption were not compromised when switching from the COBE Spectra IHD/RBCx protocol to the depletion/RBCx protocol on the Spectra Optia. Tolerability was equal for both protocols. J. Clin. Apheresis 31:429-433, 2016. © 2015 Wiley Periodicals, Inc.

Infusion pumps and red blood cell damage in transfusion therapy: an integrative revision of the academic literature / Bombas de infusão e lesão celular em hemácias na terapia transfusional: revisão integrativa da literatura / Bombas de infusión y lesión celular en glóbulos rojos en la terapia transfusional: revisión integradora de la literatura

ABSTRACT Objectives: to obtain information from scientific literature concerning infusion pumps used in administering erythrocyte (red blood cells) and to evaluate the implications in the practical use of this equipment by nurses when conducting transfusions. Method: an integrative revision of the following scientific databases: Pubmed/Medline, Scopus, the Virtual Library for Health, SciELO, Web of Science and Cochrane. The following descriptors were used: "infusion pumps", "blood transfusion", "transfused erythrocyte" and "hemolyis". There were no restrictions on the scope of the initial data and it was finalized in December 2014. 17 articles were identified in accordance with the inclusion and exclusion criteria. Results: all of the publications included in the studies were experimental in vitro and covered the use of infusion pumps in transfusion therapy. A summary of the data was presented in a synoptic chart and an analysis of it generated the following categories: cellular damage and the infusion mechanism. Conclusion: infusion pumps can be harmful to erythrocytes based on the infusion mechanism that is used, as the linear peristaltic pump is more likely to cause hemolysis. Cellular damage is related to the plasmatic liberation of markers that largely dominate free hemoglobin and potassium. We reiterate the need for further research and technological investments to guide the development of protocols that promote safe practices and that can contribute to future clinical studies.

RESUMO Objetivos: identificar na literatura a produção científica acerca dos efeitos de bomba de infusão na administração de hemácias e avaliar as implicações do uso desses equipamentos na prática transfusional de enfermagem. Método: revisão integrativa de literatura nas bases de dados Pubmed/Medline, Scopus, Biblioteca Virtual em Saúde, SciELO, Web of Science e Cochrane, utilizando os descritores "bombas de infusão", "transfusão de sangue", "transfusão de eritrócitos" e "hemólise". A data inicial não foi delimitada e a final foi dezembro de 2014. Foram identificados 17 artigos de acordo com os critérios de inclusão e exclusão. Resultados: Todas as publicações incluídas eram estudos experimentais in vitro e abordavam o uso de bombas de infusão na terapêutica transfusional. A síntese dos dados foi apresentada em quadro sinóptico e a análise gerou duas categorias relevantes: lesão celular e mecanismo de infusão. Conclusão: bombas de infusão podem ser deletérias às hemácias de acordo o mecanismo de infusão, sendo que as peristálticas lineares foram mais predisponentes à hemólise. A lesão celular foi relacionada à liberação plasmática de marcadores, predominando a hemoglobina livre e potássio. Reitera-se a necessidade de pesquisas adicionais e investimentos tecnológicos para nortear o desenvolvimento de protocolos que promovam prática segura e que subsidiem futuros estudos clínicos.

RESUMEN Objetivos: identificar en la literatura la producción científica acerca de los efectos de la bomba de transfusión en la administración de glóbulos rojos y evaluar las implicaciones del uso de esos equipos en la práctica transfusional de enfermería. Método: revisión integradora de literatura en las bases de datos Pubmed/Medline, Scopus, Biblioteca Virtual en Salud, SciELO, Web of Science y Cochrane, utilizando los descriptores "bombas de infusión", "transfusión de sangre", "transfusión de eritrocitos" y "hemolisis". La fecha inicial no fue delimitada y la final fue en diciembre de 2014. Fueron identificados 17 artículos de acuerdo con los criterios de inclusión y exclusión. Resultados: todas las publicaciones incluidas eran estudios experimentales in vitro y abordaban el uso de bombas de infusión en la terapéutica transfusional. La síntesis de los datos se presenta en un cuadro sinóptico y el análisis generó dos categorías relevantes: lesión celular y mecanismo de transfusión. Conclusión: las bombas de infusión pueden ser perjudiciales para los glóbulos rojos de acuerdo el mecanismo de transfusión, siendo que las peristálticas lineares fueron más predisponentes para la hemolisis. La lesión celular fue relacionada a la liberación plasmática de marcadores, predominando la hemoglobina libre y el potasio. Se reitera la necesidad de realizar investigaciones adicionales e inversiones tecnológicas que puedan orientar el desarrollo de protocolos que promuevan la práctica segura y que ayuden a futuros estudios clínicos.

Effects of the Sangvia blood collection system on patients undergoing elective hip surgery.

We have conducted a randomized controlled study where 164 patients were randomized to receive autologous salvaged blood collected by Sangvia™ Blood Salvage System or allogeneic red cell concentrates if transfusion was indicated by clinical judgement. The study was powered to detect if transfusion of autologous blood reduced the occurrence of postoperative infections. We found no statistical significant difference in postoperative infection rate between the groups, but this may be due to the fact that postoperative infections were diagnosed in only five patients. Increased C-reactive protein concentrations slightly above level of significance indicate that autologous blood transfusions stimulate the patient's immune system. However, there was no indication of increased transfusion reaction rate, including febrile reactions, in the autologous group. Transfusion of autologous blood did not reduce the use of allogeneic red cell concentrates. The mean use of allogeneic red cell concentrates was 0.93 units (both groups combined), indicating that the transfusion policy may have been too liberal. There was a highly significant inverse correlation between pre-operative haemoglobin concentration and transfusion of allogeneic blood. In a patient population with a low frequency of postoperative infection, a larger study is needed to clarify if autologous salvaged blood protects against postoperative infections.

Antecedentes históricos de nuestra Revista. La transfusión de glóbulos rojos sedimentados en el tratamiento de la enfermedad hemolítica del recién nacido (19 casos) / Historical background of our journal. Red blood cells transfusion in the treatment of the hemolytic disease of newborn

Se describe el método de tratamiento de la enfermedad hemolítica del recién nacido con transfusiones de glóbulos rojos sedimentados, se estudian sus fundamentos y se comentan sus ventajas sobre la exanguíneo transfusión y otros tratamientos. Se modifica la técnica de Pennell suprimiendo el uso de la jeringa de tres vías y la transfusión por presión y se utiliza el método corriente de goteo. Se aconseja el uso de dosis mayores que las indicadas por Pennell y se presenta una serie de 19 niños con enfermedad hemolítica todos con formas graves, con una mortalidad de 15,58%. En el comentario de los casos se estudian los efectos de la primera transfusión de glóbulos sedimentados y de las subsiguientes sobre la globulia, se estudia la cifra crítica que debe determinar la oportunidad y necesidad del tratamiento transfusional. Se comenta la anemia tardía de la enfermedad hemolítica.

The treatmen of the hemolitic disease of the newborn by transfusion of sedimented red cells is described. Its fundamentals are discussed and its advantages upon the ex-sanguinotransfusion and other treatments are commented. Pennell's technique is modified by supressing the three-ways syringe and the transfusion, using the current drip method. larger doses than those indicated by Pennel are advised and a serie is presented of 19 children with hemolitic disease, all serious forms with a mortality rate of 15.58%. In the commentary upon the cases the effect of the first transfusion of sedimented red cells and of the following ones upon the globulia is studied. The critical number that should determine the oportunity and necessity of transfusional treatment is studied. The late anemia of hemolitic disease is commented.

Hemolysis of red blood cells after cell washing with different automated technologies: clinical implications in a neonatal cardiac surgery population.

BACKGROUND: In subsets of pediatric cardiac surgery patients, red blood cells (RBCs) are often washed to reduce extracellular potassium (K) to avoid hyperkalemia, but mechanical manipulation and time delay in issuing washed products may increase hemolysis and K. This study's purpose was to evaluate the quality of washed RBCs with regard to hemolysis and extracellular K using different cell washers as a function of postprocessing time. STUDY DESIGN AND METHODS: Fresh (<4 days old) RBCs were washed on COBE 2991 blood cell processors (Model 1 and Model 2) or the Fresenius Continuous AutoTransfusion System (CATS), and K and hemolysis index (HI) were analyzed. Academic pediatric hospitals were surveyed to ascertain practice trends regarding indications for washing, washing device, and expiration time for washed RBCs. RESULTS: K concentration at 24 hours for units washed with the COBE devices met or exceeded prewash values. At 12 hours, there was a significant difference (p < 0.001) in K concentration between all devices, with the CATS maintaining the lowest K concentration. HI increased immediately after wash on all devices and showed a significant difference between the COBE devices and CATS at times of more than 6 hours (p < 0.01). At storage times beyond 4 hours, hemoglobin exceeded 100 mg/dL on the COBE Model 1. Survey of pediatric hospitals indicated that COBE devices are commonly used, and storage time after washing was 12 hours or more in blood banks queried. CONCLUSIONS: Hemolysis levels vary among different cell washers. Decreasing the expiration time of units after washing may be warranted.

Red blood cells from pluripotent stem cells for use in transfusion.

The use of donated red blood cells in transfusion is a well-established cellular therapy. However, problems including insufficient supply, transfusion-transmitted infections and the need for immunological matching hamper even in the best services. These issues may be eliminated by using pluripotent stem cells to generate universal donor group O, Rhesus D-negative red blood cells. Human embryonic stem cells can be maintained and expanded indefinitely and can, therefore, produce the very large cell numbers required for this application. Red blood cell production is also an attractive goal for pluripotent stem cell-derived therapeutics because it is a well-characterized single cell suspension, lacking nucleated cells and with a low expression of HLA molecules. Much progress has been made; however, a number of challenges remain including scale-up, clinical effectiveness and product safety.

The Haemonetics Cell Saver 5 washing properties: effect of different washing pump and centrifuge speeds.

This study evaluated the effect of different washing and centrifuge rates of the Cell Saver 5 on the quality of processed autologous blood. Autologous blood was washed with 1000 ml of sterile normal saline at centrifuge speed of 5650 revolutions per minute (rpm) (group I) or 4350 rpm (group II) with different washing pump speeds--500, 800 and 1000 ml/min. Hemoglobin, free hemoglobin, hematocrit, erythrocytes, leukocytes, platelets, and protein were measured before and after processing. The highest values of hemoglobin, hematocrit and erythrocytes were achieved using 800 and 1000 ml/min pump speeds in group I and 500 ml/min speed in group II. Red blood cells concentration was higher in group I. There were no significant changes of free hemoglobin removal within group I. In group II the lowest free hemoglobin was achieved when 1000 ml/min rate was used. Platelets and protein did not depend on wash pump speeds in both groups. Platelet recovery in group I was higher than in group II at all washing pump speeds. Leukocytes were not adequately removed at all pump speeds. The Cell Saver 5 produces optimum results when the high wash pump speeds (800 and 1000 ml/min) and standard centrifuge speed are used.

[Efficacy of intraoperative apparatus autotransfusion of the blood in revisional endoprosthesis of the hip joint].

Significant blood loss and the methods of its compensation constitute one of the main problems of revisional prosthesis of big joints. Application of a patient's blood constitutes the most available and secure way of the problem solution at the modern stage of surgery evolution. The apparatus autotransfusion of the blood owes prominent place in the system of the blood saving, solely as well as in combination with autodonoring and preoperative hemodilution. In the patients, to whom the revisional prosthesis of the hip joint was performed, using intraoperative apparatus autotransfusion of the blood and the donor's erythrocytes, the red blood indexes were investigated on the stages of operative intervention and postoperative period. Application of apparatuses, such as Cell Saver, constitutes optimal and secure method of the blood oxygentransporting function restoration in the revisional prosthesis of big joints operations.

Quality of red blood cells using the Dideco Electa autotransfusion device.

The purpose of this study was to evaluate the quality of washed, concentrated red blood cells (RBCs) produced by the new Electa autotransfusion device from Cobe Cardiovascular (Dideco). Blood was collected intraoperatively in 16 patients undergoing cardiac surgery for whom routine cell savage was being used and then washed using the Electa. According to the manufacture's protocol. 125-mL bowls were used in the standard wash program. Reservoir and washed RBCs were analyzed for platelets (PLTs), leukocytes (WBCs), potassium (K+), and plasma-free hemoglobin (PFH) removal, as well as, hematocrit (Hct) and RBC recovery. The Electa cell saver produced a product with an average Hct of 58+/-5% and a RBC recovery rate of 87+/-10%. Its removal of waste products resulted in the washout of 54+/-18% WBCs, 87+/-6% PLTs, 91+/-4% K+, and 77+/-17% PFH. The Electa produces a good-quality washed RBC product that is comparable with other autotransfusion devices on the market.

Implementation of concurrent red blood cell and platelet collection by apheresis in a university haemapheresis unit.

The present study analyses the number of concurrently collected red blood cell (RBC) units in plateletpheresis donors and the reasons why donors were deferred from multicomponent collection. Donors undergoing concurrent collection of RBCs and platelets (PLTs) were retrospectively evaluated for haemoglobin values and the reasons for deferral over a period of 1 year. A total of 404 RBC units were concurrently collected with PLTs. An average of 1.8 RBC units per year was collected from each donor. The baseline haemoglobin values were almost equal for the RBC donations. An RBC unit was not collected in 190 aphereses. Most frequent reasons for the noncollection of an RBC product were a donation interval of less than 3 months (20.5%), haematoma and blood flow problems (18.9%) and low pre-haemoglobin values (17.4%). Donor eligibility has to be taken into account to optimize concurrent RBC collection in plateletpheresis.

Quality of packed red blood cells and platelet concentrates collected by multicomponent collection using the MCS plus device.

The demand for blood components is constantly increasing, while the exclusion criteria for donors are strengthened in order to reach maximal safety for donors and patients. To counterbalance reduced availability of volunteers, multicomponent collections (MCC) is an attractive approach to produce more than one component during a single apheresis procedure from one donor, such as packed red blood cells (PRBCs) and platelet concentrates (PCs). Further, the exposures of patients to a limited number of donors reduces the possibility of alloimmunization and transfusion-related diseases. We measured the quality of PRBCs and PCs obtained by MCC, using the MCS+ device with the LDPRBC program, Revision B, and compared them with the quality of manually collected PRBCs and PCs collected with the Revision C2 of the MCS+. We found higher pH levels and lower hemolysis assessed by means of fHb and K+ in the supernatant of PRBCs over the whole storage period of 42 days in MCC-derived PRBCs. The functional metabolism assessed by intracellular ATP was higher in PRBCs collected by MCC than in manually collected units. Furthermore, PCs obtained during MCC showed an increase in p-selectin expression on day 5 of storage compared to PCs collected with the Revision C2 of the MCS+. The p-selectin expression on MCC platelets was within the range of p-selectin expression found in PCs obtained by other apheresis devices. These results indicate less storage lesion in MCC-derived PRBCs compared to manually collected units and no compromise in the quality of MCC PCs obtained in the same apheresis procedure.

[Autotransfusion after cardiac surgery. Hematological, biochemical and immunological properties of shed mediastinal blood]. / Autotransfusión postoperatoria en cirugía cardíaca. Características hematológicas, bioquímicas e inmunológicas de la sangre recuperada del drenaje mediastínico.

OBJECTIVE: Although it is well documented that the reinfusion of unwashed shed blood reduces postoperative homologous blood requirements after cardiac surgery, the efficacy and safety of the technique has been questioned on the basis of several possible adverse effects. We therefore aimed to evaluate the extent of mediastinal shed blood damage by cardiopulmonary bypass (CPB) and extravasation. PATIENTS AND METHOD: Five perioperative blood samples were obtained from each of the 20 patients undergoing cardiac surgery: by venipuncture, during the induction of anesthesia (sample 1), at the end of CPB (sample 2), and one hour after mediastinal shed blood reinfusion (sample 5), and from the cardiotomy reservoir at the first and sixth postoperative hours (samples 3 and 4). Hematological, biochemical and immunological parameters, and the metabolic and functional status of shed erythrocytes were studied in each sample. RESULTS: Hematological and biochemical values were lower at the end of CPB and in shed blood, but not after reinfusion. Inversely, plasma free hemoglobin levels and echinocyte formation were elevated after CPB and in shed blood, the latter correlating with the decrease in serum albumin levels due to hemodilution. No alterations were detected in erythrocyte median corpuscular fragility, D-glucose, L-phenylalanine and L-serine uptakes or 2,3-bisphosphoglycerate content. Plasma IL-10 levels were elevated at the end of CPB, whereas shed blood showed increased levels of IL-1beta, IL-6 and IL-10. Shed blood retrieval did not modify the pattern of circulating cytokines found at the end of CPB. CONCLUSIONS: Shed mediastinal blood salvaged after cardiac surgery seems to be an excellent source of red cells, which conserve functional and metabolic status; once reinfused, shed blood does not modify the inflammatory response of the patient to CPB.

Use of a prestorage leukoreduction filter effectively removes leukocytes from canine whole blood while preserving red blood cell viability.

Leukoreduction of blood products is a technique used to prevent leukocyte-induced transfusion reactions. Filters currently used for human blood products achieve at least a 99.9% reduction in leukocyte numbers per unit (450 mL) of blood. Goals of this study were to determine if a prestorage leukoreduction filter could effectively achieve leukoreduction of canine blood and to determine if viability of the leukoreduced red blood cell (RBC) product could be maintained after 35 days of storage. Blood collected from each dog was filtered through a leukoreduction filter at either room temperature or after cooling (4 degrees C) for 4 hours. Filtration efficacy was determined by measurement of pre- and postfiltration leukocyte counts. In vitro viability of RBCs was determined by comparing RBC adenosine triphosphate concentration and percent hemolysis before and after the storage period. In vivo viability of stored cells was determined using a biotin-streptavidin-phycoerythrin labeling technique and flow cytometry. Blood filtered within 30 minutes of collection versus blood filtered after cooling had mean reductions in leukocyte numbers of 88.90 and 99.99%, respectively. The mean ATP and hemoglobin concentrations from the in vitro analysis were comparable to those obtained in previously for canine RBC adequately stored for 35 days. The mean in vivo 24-hour survival of the stored RBC was 84.7%. The leukoreduction filter used did not adversely affect in vitro or in vivo viability of canine RBCs. The filter effectively removed leukocytes from blood, with maximal efficiency of filtration achieved with use of cooled blood.

Quality of processed blood for autotransfusion.

Centrifugal red blood cell washers for intraoperative autotransfusion process shed blood during surgery. In this study, the quality of processed fresh, human bank blood was assessed in a standardized laboratory setting during standard, medium, and high flow processing. Red cell recovery rates and plasma washout efficiencies were compared using three different devices. The accurate parameters measuring effectiveness and product quality were red cell mass (RCM) flow rate and the plasma washout efficiency. Cobe BRAT 2, a system with discontinuous flow (DF) and a cylindrical centrifuge bowl, permitted processing in standard and medium flow of 26 and 35 mL RCM/min, respectively, with washout of residual plasma albumin of 93.2 and 91.2%. The Medtronic Sequestra 1000, a DF system with a conical centrifuge bowl processed blood at 15 and 23 mL RCM/min and eliminated plasma albumin with 98.4 and 96.8% washout during standard and medium flow, respectively, with significant red cell loss occurring during medium flow. The respective speeds of high-flow programs with BRAT 2 and Sequestra 1000 were 15 and 22 mL RCM/min, related to a hematocrit in the holding bag, less than that of the incoming blood from the reservoir. Washout was 58.2 and 58.3%, respectively. Fresenius CATS, a continuous flow (CF) device, produced flow rates of 19, 24, and 43 mL RCM/min and plasma albumin elimination of 97.8, 94.4, and 93.3% in standard, medium, and high-flow, respectively. Holding bag hematocrits with CF exceeded that of DF. Standard, medium, and high-flow programs of CATS may be used without restriction.

Continuous monitoring of arterial blood gases and pH during intraoperative rapid blood administration using a Paratrend sensor.

BACKGROUND AND OBJECTIVES: The aim of this study was to determine the effects of rapid transfusion of packed red cells on the arterial blood gases and acid-base status of the recipient. MATERIALS AND METHODS: We studied 16 patients (mean age 66.3+/-9.9 years) who received rapid transfusion of 632.8+/-287.2 g of packed red cells in CPDA-1, stored before use for a period of 15.2+/-4.4 days. During transfusion, monitoring of pH, PCO2 and PO2 was continuous using an intra-arterial multiparameter sensor (Paratrend 7, Biomedical Sensors, UK). RESULTS: The rate of the transfusion was 73.1+/-9.6 g/min and the duration of observation was 35.8+/-12.8 min. Arterial pH decreased from 7.446+/-0.023 to 7.385+/-0.034 (p<0.001) and PCO2 increased from 32.31+/-1.35 to 36.41+/-1.86 mmHg (p<0.001). Delta pH and delta PCO2 showed significant correlation to the weight and the age of the transfused blood (p<0.001 for both dependent variables). The rate of pH change was positively but insignificantly correlated to the rate of the transfusion. Base excess was significantly decreased and end-tidal CO2 (PetCO2) was increased from 25.8+/-2.0 to 28.1+/-2.3 mmHg (p<0.05), significantly correlating to the amount and age of the administered component (p<0.05). PetCO2 was not elevated when PCO2 changes were minimal. Alterations in PO2 were not specific and our clinical impression was that they were related to unmeasured parameters. CONCLUSION: Our findings suggest that the fall in pH and the elevation in PCO2 which occur during rapid transfusion of packed red cells may go undetected or be misinterpreted if the acid-base status of the recipient is not monitored continuously. These alterations are mainly of metabolic character and depend on the amount and age of the transfused component. Our data suggest that arterial sampling is essential during massive transfusions.