Infectious complications after cardiac surgery: lack of association with fresh frozen plasma or platelet transfusions

Fresh frozen plasma transfusion after cardiac surgery

INTRODUCTION

Fresh frozen plasma (FFP) transfusion in the intensive care unit (ICU) is commonly used to treat coagulopathy and bleeding in cardiac surgery, despite suggestion that it may increase the risk of morbidity and mortality through mechanisms such as fluid overload and infection.

METHODS

We retrospectively studied consecutive adults undergoing cardiac surgery from the Medical Information Mart for Intensive Care III and IV databases. We applied propensity score matching to investigate the independent association of within-ICU FFP transfusion with mortality and other key clinical outcomes.

RESULTS

Of our 12,043 adults who met inclusion criteria, 1585 (13.2%) received perioperative FFP with a median of 2.48 units per recipient (interquartile range [IQR]: 2.04, 4.33) at a median time of 1.83 h (IQR: 0.75, 3.75) after ICU admission. After propensity matching of 952 FFP recipients to 952 controls, we found no significant association between FFP use and hospital mortality (odds ratio (OR): 1.58; 99% confidence interval (CI): 0.57, 3.71), suspected infection (OR: 0.72; 99% CI: 0.49, 1.08), or acute kidney injury (OR: 1.23; 99% CI: 0.91, 1.67). However, FFP was associated with increased days in hospital (adjusted mean difference (AMD): 1.28; 99% CI: 0.27, 2.41; p = .0050), days in intensive care (AMD: 1.28; 99% CI: 0.27, 2.28; p = .0011), and chest tube output in millilitres up to 8 h after transfusion (AMD: 92.98; 99% CI: 52.22, 133.74; p < .0001).

CONCLUSIONS

After propensity matching, FFP transfusion was not associated with increased hospital mortality, but was associated with increased length of stay and no decrease in bleeding in the early post-transfusion period.

Trends and outcomes in multicomponent blood transfusion: an 11-year cohort study of a large multisite academic center

BACKGROUND

Most studies reporting on blood component utilization overlook patients transfused with more than one type of blood product (multicomponent transfusion). These patients are of importance, as they are large consumers of blood products and likely have different characteristics and outcomes than nontransfused patients and patients transfused with only one blood component type. Our study aimed to determine the prevalence of multicomponent transfusion at a large multisite academic center, as well as the patient characteristics and outcomes associated with multicomponent transfusion.

METHODS

A retrospective cohort study of transfused adult inpatients at the Ottawa Hospital between 2007 and 2017 was performed. Eligible transfusions were red blood cells (RBCs), platelets, plasma, cryoprecipitate, and/or fibrinogen concentrate. Descriptive analyses were done to determine multicomponent transfusion prevalence. Patient characteristics and outcomes associated with multicomponent transfusion were assessed using multivariable regressions.

RESULTS

Of 55,719 adult transfused inpatient admissions, 25% received a multicomponent transfusion. Multicomponent transfusion prevalence was highest in hematology (51%), cardiac surgery (45%), and critical care (40%) patients. Multivariable regression analysis showed that compared to RBC-only transfusion, multicomponent transfusion was associated with increased odds of in-hospital mortality (odds ratio, 3.48; 95% confidence interval [CI], 3.26-3.73), greater odds of institutional discharge as opposed to discharge home (odds ratio, 1.22; 95% CI, 1.15-1.30), and a 1.58 time increase in duration of hospitalization (95% CI, 1.54-1.62).

CONCLUSION

Multicomponent transfusion recipients make up a large proportion of transfused patients and have poorer outcomes. It is necessary to continue studying these patients, including outcomes and transfusion appropriateness, to inform best practices.

Variation in Platelet Transfusion Practices in Cardiac Surgery

Objective

Although the morbidity associated with red blood cell transfusion in cardiac surgery has been well described, the impacts of platelet transfusion are less clearly understood. Given the conflicting results of prior studies, we sought to investigate the impact of platelet transfusion on outcomes after cardiac surgery across institutions in Maryland.

Methods

Using a multiinstitutional statewide database created by the Maryland Cardiac Surgery Quality Initiative, we retrospectively analyzed data from 10,478 patients undergoing isolated coronary artery bypass across 10 centers. Platelet transfusion practices were compared between institutions. Multivariate logistic regression model was used to analyze the association between platelet transfusion and 30-day mortality and postoperative complications.

Results

Rates of platelet transfusion varied between institutions from 4.4% to 24.7% ( P < 0.001), a difference that remained statistically significant in propensity score–matched cohorts. Among patients on preoperative antiplatelet therapy, transfusion rates varied from 8.5% to 46.4% ( P < 0.001). There was no statistically significant relationship between case volume and transfusion rates ( P = 0.815). In multivariate logistic regression, platelet transfusion was associated with increased risk of 30-day mortality (OR 2.43, P = 0.008), postoperative pneumonia (OR 2.21, P = 0.004), prolonged intubation (OR 2.05, P < 0.001), and readmission (OR 1.43, P = 0.039).

Conclusions

Significant variation existed in platelet transfusion rates between institutions, even after controlling for various risk factors. This variation may be associated with increased mortality and length of stay. Further study is warranted to better understand risks associated with platelet transfusion. Standardizing practice may help reduce risk and conserve resources.

Korean clinical practice guideline for perioperative red blood cell transfusion from Korean Society of Anesthesiologists

Background

Considering the functional role of red blood cells (RBC) in maintaining oxygen supply to tissues, RBC transfusion can be a life-saving intervention in situations of severe bleeding or anemia. RBC transfusion is often inevitable to address intraoperative massive bleeding; it is a key component in safe perioperative patient management. Unlike general medical resources, packed RBCs (pRBCs) have limited availability because their supply relies entirely on voluntary donations. Additionally, excessive utilization of pRBCs may aggravate prognosis or increase the risk of developing infectious diseases. Appropriate perioperative RBC transfusion is, therefore, crucial for the management of patient safety and medical resource conservation. These concerns motivated us to develop the present clinical practice guideline for evidence-based efficient and safe perioperative RBC transfusion management considering the current clinical landscape.

Methods

This guideline was obtained after the revision and refinement of exemplary clinical practice guidelines developed in advanced countries. This was followed by rigorous evidence-based reassessment considering the healthcare environment of the country.

Results

This guideline covers all important aspects of perioperative RBC transfusion, such as preoperative anemia management, appropriate RBC storage period, and leukoreduction (removal of white blood cells using filters), reversal of perioperative bleeding tendency, strategies for perioperative RBC transfusion, appropriate blood management protocols, efforts to reduce blood transfusion requirements, and patient monitoring during a perioperative transfusion.

Conclusions

This guideline will aid decisions related to RBC transfusion in healthcare settings and minimize patient risk associated with unnecessary pRBC transfusion.

Does a Platelet Transfusion Independently Affect Bleeding and Adverse Outcomes in Cardiac Surgery?

Background

Conflicting results have been reported concerning the effect of platelet transfusion on several outcomes. The aim of this study was to assess the independent effect of a single early intraoperative platelet transfusion on bleeding and adverse outcomes in cardiac surgery patients.

Methods

For this observational study, 23,860 cardiac surgery patients were analyzed. Patients who received one early (shortly after cardiopulmonary bypass while still in the operating room) platelet transfusion, and no other transfusions, were defined as the intervention group. By matching the intervention group 1:3 to patients who received no early transfusion with most comparable propensity scores, the reference group was identified.

Results

The intervention group comprised 169 patients and the reference group 507. No difference between the groups was observed concerning reinterventions, thromboembolic complications, infections, organ failure, and mortality. However, patients in the intervention group experienced less blood loss and required vasoactive medication 139 of 169 (82%) versus 370 of 507 (74%; odds ratio, 1.65; 95% CI, 1.05 to 2.58), prolonged mechanical ventilation 92 of 169 (54%) versus 226 of 507 (45%; odds ratio, 1.47; 94% CI, 1.03 to 2.11), prolonged intensive care 95 of 169 (56%) versus 240 of 507 (46%; odds ratio, 1.49; 95% CI, 1.04 to 2.12), erythrocytes 75 of 169 (44%) versus 145 of 507 (34%; odds ratio, 1.55; 95% CI, 1.08 to 2.23), plasma 29 of 169 (17%) versus 23 of 507 (7.3%; odds ratio, 2.63; 95% CI, 1.50–4.63), and platelets 72 of 169 (43%) versus 25 of 507 (4.3%; odds ratio, 16.4; 95% CI, 9.3–28.9) more often compared to the reference group.

Conclusions

In this retrospective analysis, cardiac surgery patients receiving platelet transfusion in the operating room experienced less blood loss and more often required vasoactive medication, prolonged ventilation, prolonged intensive care, and blood products postoperatively. However, early platelet transfusion was not associated with reinterventions, thromboembolic complications, infections, organ failure, or mortality.

Deep sternal wound infection after cardiac surgery: Evidences and controversies

Despite many advances in prevention and perioperative care, deep sternal wound infection (DSWI) remains a pressing concern in cardiac surgery, with a still relevant incidence and with a considerable impact on in-hospital mortality and also on mid- and long-term survival. The permanent high impact of this complication is partially related to the increasing proportion of patients at high-risk for infection, as well as to the many patient and surgical risk factors involved in the pathogenesis of DSWI. The prophylactic antibiotic therapy is one of the most important tools in the prevention of DSWI. However, the choice of antibiotic, the dose, the duration, the adequate levels in serum and tissue, and the timing of antimicrobial prophylaxis are still controversial. The treatment of DSWI ranges from surgical revision with primary closure to surgical revision with open dressings or closed irrigation, from reconstruction with soft tissue flaps to negative pressure wound therapy (NPWT). However, to date, there have been no accepted recommendations regarding the best management of DSWI. Emerging evidence in the literature has validated the efficacy and safety of NPWT either as a single-line therapy, or as a “bridge” prior to final surgical closure. In conclusion, the careful control of patient and surgical risk factors - when possible, the proper antimicrobial prophylaxis, and the choice of validated techniques of treatment could contribute to keep DSWIs at a minimal rate.

Practice guidelines for perioperative blood management: an updated report by the American Society of Anesthesiologists Task Force on Perioperative Blood Management*

The American Society of Anesthesiologists Committee on Standards and Practice Parameters and the Task Force on Perioperative Blood Management presents an updated report of the Practice Guidelines for Perioperative Blood Management.

Supplemental Digital Content is available in the text.

A multivariate analysis to assess the effect of packed red cell transfusion and the unit age of transfused red cells on postoperative complications in patients undergoing cardiac surgeries

BACKGROUND

Transfusion of blood components and age of transfused packed red cells (PRCs) are independent risk factors for morbidity and mortality in cardiac surgeries.

MATERIALS AND METHODS

We retrospectively examined data of patients undergoing cardiac surgery at our institute from January 1, 2012 to September 30, 2012. Details of transfusion (autologous and allogenic), postoperative length of stay (PLOS), postoperative complications were recorded along with other relevant details. The analysis was done in two stages, in the first both transfused and nontransfused individuals and in the second only transfused individuals were considered. Age of transfused red cells as a cause of morbidity was analyzed only in the second stage.

RESULTS

Of the 762 patients included in the study, 613 (80.4%) were males and 149 (19.6%) were females. Multivariate analysis revealed that factors like the number and age of transfused PRCs and age of the patient had significant bearing upon the morbidity. Morbidity was significantly higher in the patients transfused with allogenic PRCs when compared with the patients not receiving any transfusion irrespective of the age of transfused PRCs. Transfusion of PRC of over 21 days was associated with higher postoperative complications, but not with in-hospital mortality.

CONCLUSION

In patients undergoing cardiac surgery, allogenic blood transfusion increases morbidity. The age of PRCs transfused has a significant bearing on morbidity, but not on in-hospital mortality. Blood transfusion services will therefore have to weigh the risks and benefits of providing blood older than 21 days in cardiac surgeries.

Transfusion of packed red blood cells is not associated with improved central venous oxygen saturation or organ function in patients with septic shock

BACKGROUND

The exact role of packed red blood cell (PRBC) transfusion in the setting of early resuscitation in septic shock is unknown.

STUDY OBJECTIVE

To evaluate whether PRBC transfusion is associated with improved central venous oxygen saturation (ScvO(2)) or organ function in patients with severe sepsis and septic shock receiving early goal-directed therapy (EGDT).

METHODS

Retrospective cohort study (n=93) of patients presenting with severe sepsis or septic shock treated with EGDT.

RESULTS

Thirty-four of 93 patients received at least one PRBC transfusion. The ScvO(2) goal>70% was achieved in 71.9% of the PRBC group and 66.1% of the no-PRBC group (p=0.30). There was no difference in the change in Sequential Organ Failure Assessment (SOFA) score within the first 24 h in the PRBC group vs. the no-PRBC group (8.6-8.3 vs. 5.8-5.6, p=0.85), time to achievement of central venous pressure>8 mm Hg (732 min vs. 465 min, p=0.14), or the use of norepinephrine to maintain mean arterial pressure>65 mm Hg (81.3% vs. 83.8%, p=0.77).

CONCLUSIONS

In this study, the transfusion of PRBC was not associated with improved cellular oxygenation, as demonstrated by a lack of improved achievement of ScvO(2)>70%. Also, the transfusion of PRBC was not associated with improved organ function or improved achievement of the other goals of EGDT. Further studies are needed to determine the impact of transfusion of PRBC within the context of early resuscitation of patients with septic shock.

Postoperative complications associated with transfusion of platelets and plasma in cardiac surgery

BACKGROUND

Studies in cardiac surgery have reported increased postoperative morbidity and mortality after allogeneic red blood cell (RBC) transfusions. Whether platelet (PLT) and/or plasma transfusions are a marker for more concomitant RBC transfusions or are independently associated with complications after cardiac surgery is unknown.

STUDY DESIGN AND METHODS

Data from two randomized controlled studies were combined to analyze the effects of PLT and/or plasma transfusions on postoperative infections, length of stay in the intensive care unit (ICU), all-cause mortality, and mortality in the presence or absence of infections in the postoperative period.

RESULTS

After adjusting for confounding factors, plasma units and not RBC transfusions were associated with all-cause mortality. White blood cell (WBC)-containing RBC transfusions and PLT transfusions were associated with mortality occurring in the presence of or after infections. The number of (WBC-containing) RBC transfusions was also significantly associated with postoperative infections and with ICU stay for 4 or more days.

CONCLUSION

Although it is difficult to separate the effects of blood components, we found that in cardiac surgery, perioperative plasma transfusions are independently associated with all-cause mortality. WBC-containing RBC transfusions and PLT transfusions are independently associated with mortality in the presence of infections in the postoperative period. Future transfusion studies in cardiac surgery should concomitantly consider the possible adverse effects of all the various transfused blood components.

Age of transfused blood is not associated with increased postoperative adverse outcome after cardiac surgery

BACKGROUND

This study investigated the hypothesis that storage age of transfused red blood cells (RBCs) is associated with adverse outcome after cardiac surgery, and examined association between volume of RBC transfusions and outcome after cardiac surgery.

METHODS

Adult patients undergoing first time elective/urgent cardiac surgery who had received RBC transfusion perioperatively were included. Three prospective institutional databases were linked. Patients were grouped according to the oldest storage age of any RBCs transfused: those who received only RBCs stored for ≤14 days, only RBCs stored for >14 days, and a mixture of both ages of blood. The effect of RBC age on early mortality, postoperative ventilation ≥72 h, renal failure, pulmonary and infectious complications, length of intensive care stay, and postoperative ventilation time was examined using regression analyses with adjustment for confounding factors, including number of units transfused.

RESULTS

Data were analysed on 1153 patients who received a total of 5962 RBC units. There was no difference in adjusted odds of any outcome between the ≤14 days group and the group who received RBCs aged >14 days. Multivariate logistic regression analyses disclosed number of RBC units transfused as the most consistent factor associated with major postoperative complications, P<0.0001 in all cases. A trend of increasing complication rate was observed with more units transfused.

CONCLUSIONS

Storage age of RBC transfusion up to 35 days was not associated with increased postoperative adverse outcome after cardiac surgery. The number of RBC units transfused is consistently associated with adverse outcome.

The effect of postoperative gastrointestinal complications in patients undergoing coronary artery bypass surgery

BACKGROUND

Gastrointestinal (GI) complications after coronary artery bypass graft surgery (CABG) are uncommon but associated with a disproportionate share of mortality. We thus identified variables associated with GI complications and analyzed their effect on postoperative mortality in patients undergoing isolated CABG.

METHODS

Information from patients who underwent isolated CABG at our institution during a 12-year period was obtained from the Anesthesiology Institute patient registry. Patients who experienced one or more postoperative GI complication(s) during their initial intensive care unit stay were identified. Multivariable logistic regression with backward variable selection was used to determine variables associated with GI complications and to evaluate their effect on mortality.

RESULTS

Among 16,043 patients who underwent isolated CABG, 213 (1.43%) had one or more GI complication(s). The main patient variables associated with postoperative GI complications included preoperative (odds ratio, 2.43; 95% confidence interval [CI], 1.39 to 4.23; p < 0.001) and intraoperative (odds ratio, 5.07; 95% CI, 3.08 to 8.35; p < 0.001) intraaortic balloon pump insertion, patient age (odds ratio, 1.65; 95% CI, 1.41 to 1.94; p < 0.001), intraoperative fresh-frozen plasma transfusion (odds ratio, 3.38; 95% CI, 2.12 to 5.41; p < 0.001), and cardiogenic shock (odds ratio, 3.04; 95% CI, 1.12 to 8.24). No difference was detected in complication rates between off-pump and on-pump CABG procedures (1.50% versus 1.30%, respectively; p = 0.63). Postoperative GI complication(s) after CABG was associated with a 12.98 times increase in mortality (p < 0.001).

CONCLUSIONS

This single-center cohort study indicates that GI complications after isolated CABG remain rare with an incidence 1.43%. However, GI complications portend a significant mortality. The implications of intraoperative administration of fresh-frozen plasma and insertion of an intraaortic balloon pump deserve further investigation as they are associated with GI complications.

Hospital variation in transfusion and infection after cardiac surgery: a cohort study

BACKGROUND

Transfusion practices in hospitalised patients are being re-evaluated, in part due to studies indicating adverse effects in patients receiving large quantities of stored blood. Concomitant with this re-examination have been reports showing variability in the use of specific blood components. This investigation was designed to assess hospital variation in blood use and outcomes in cardiac surgery patients.

METHODS

We evaluated outcomes in 24,789 Medicare beneficiaries in the state of Michigan, USA who received coronary artery bypass graft surgery from 2003 to 2006. Using a cohort design, patients were followed from hospital admission to assess transfusions, in-hospital infection and mortality, as well as hospital readmission and mortality 30 days after discharge. Multilevel mixed-effects logistic regression was used to calculate the intrahospital correlation coefficient (for 40 hospitals) and compare outcomes by transfusion status.

RESULTS

Overall, 30% (95 CI, 20% to 42%) of the variance in transfusion practices was attributable to hospital site. Allogeneic blood use by hospital ranged from 72.5% to 100% in women and 49.7% to 100% in men. Allogeneic, but not autologous, blood transfusion increased the odds of in-hospital infection 2.0-fold (95% CI 1.6 to 2.5), in-hospital mortality 4.7-fold (95% CI 2.4 to 9.2), 30-day readmission 1.4-fold (95% CI 1.2 to 1.6), and 30-day mortality 2.9-fold (95% CI 1.4 to 6.0) in elective surgeries. Allogeneic transfusion was associated with infections of the genitourinary system, respiratory tract, bloodstream, digestive tract and skin, as well as infection with Clostridium difficile. For each 1% increase in hospital transfusion rates, there was a 0.13% increase in predicted infection rates.

CONCLUSION

Allogeneic blood transfusion was associated with an increased risk of infection at multiple sites, suggesting a system-wide immune response. Hospital variation in transfusion practices after coronary artery bypass grafting was considerable, indicating that quality efforts may be able to influence practice and improve outcomes.

Impact of fresh-frozen plasma from male-only donors versus mixed-sex donors on postoperative respiratory function in surgical patients: a prospective case-controlled study

BACKGROUND

To reduce the risk of transfusion-related acute lung injury (TRALI), plasma products are mainly made from male donors in some countries because of the lower possibility of alloimmunization; other countries are considering this policy. The advantage of male-only fresh-frozen plasma (FFP) should be examined in a prospective case-control study.

STUDY DESIGN AND METHODS

This study compared pulmonary function after the transfusion of FFP derived from either male donors only (FFP-male) or mixed donors (FFP-mixed) in informed surgical patients treated at a tertiary university hospital in Japan. The factors contributing to pulmonary distress (PD) after transfusion were then statistically examined.

RESULTS

Eighty-two patients participated in this study (FFP-male, n = 55; FFP-mixed, n = 27). Nineteen patients developed PD (PaO(2)/FiO(2) ratio [P/F] < 300) within 6 hours after transfusion: seven had congestive pulmonary edema (transfusion-associated circulatory overload), five had permeability pulmonary edema (possible TRALI), and seven had no apparent pulmonary edema. A multivariate logistic regression analysis revealed that the use of cardiopulmonary bypass and preoperative liver dysfunction were significantly associated with a P/F of less than 300 (odds ratios [ORs], 8.95 [p = 0.004] and 6.54 [p = 0.005], respectively), while the use of FFP-male was significantly associated with the absence of PD (OR, 0.219; p = 0.022). All the patients with possible TRALI had received either white blood cell or granulocyte antibody-positive FFP. The lysophosphatidylcholine level was not correlated with PD.

CONCLUSIONS

Our data suggests that the use of FFP derived from male donors may be advantageous for posttransfusion pulmonary function, although PD is also determined by background characteristics.

Soluble Human Leukocyte Antigen class I antigen and interleukin-12 in hepatectomized patients

BACKGROUND

Interleukin-12 (IL-12) has been shown to enhance the cytotoxic activity of NK cells and CTL. IL-12 also acts as a growth factor for activated NK, T and NKT cells. The soluble HLA class I (sHLA-I) has been reported to bind a killer-cell inhibitory receptor, which is expressed on the NK cell, and its signals inhibit NK cell-mediated cytotoxicity. Effects of fresh frozen plasma (FFP) on post-operative immune status have not yet been completely examined.

METHODS

Thirty consecutive patients taking a hepatectomy were enrolled. The levels of IL-12 and sHLA-I were examined by enzyme-linked immunosorbent assay.

RESULTS

The rate of complication after hepatectomy in the FFP-administered patients was higher than that in patients without FFP administration (P = 0.0358). Decreased IL-12 levels after surgery in patients without FFP administration recovered to the preoperative state earlier than those in patients with FFP administration (P < 0.05). The levels of sHLA-I in the FFP-administered patients were higher than those in the patients without FFP administration (P < 0.05).

CONCLUSIONS

Administration of FFP, which contains sHLA-I, affected the levels of sHLA-I after hepatectomy. Both high levels of sHLA-I and low levels of IL-12 could attenuate NK activities after hepatectomy, especially when FFP would be administered.

Blood product transfusion and ventilator-associated pneumonia in trauma patients

BACKGROUND

Ventilator-associated pneumonia (VAP) is the most common nosocomial infection in trauma patients, with a high mortality rate. Blood transfusion has been identified as an independent risk factor for VAP in critically ill patients. Prior studies in trauma are limited by retrospective design, lack of multivariable analyses, and scant data on the timing of transfusion. We examined critically the relation between blood product transfusion and VAP in trauma patients.

METHODS

Prospective observational cohort study of 766 trauma patients admitted to the intensive care unit (ICU), who received mechanical ventilation (MV) for >or= 48 h, and who did not have pneumonia on admission. Late-onset VAP was defined as that occurring >or= 72 h after MV. Only transfusions of red blood cell (RBC) concentrate, fresh-frozen plasma (FFP), or platelets before the onset of VAP were considered. Logistic regression analyses controlled for all variables related significantly to VAP by univariate analysis (sex, Injury Severity Score, and ventilator days and ICU length of stay prior to VAP).

RESULTS

A significantly greater proportion of male patients developed VAP. Patients with VAP had a longer duration of MV: The mean number ventilator days prior to VAP was 11.1 +/- 8.0. Transfusion of blood products was an independent risk factor for VAP, and the risk increased with more units transfused. All blood products were associated with a higher risk of VAP (RBC: odds ratio [OR] 4.41; 95% confidence interval [CI] 1.00, 19.54; p = 0.05; FFP: OR 3.34; 95% CI 1.18, 9.43; p = 0.023; platelets: OR 4.19; 95% CI 1.37, 12.83; p = 0.012).

CONCLUSION

Blood product transfusion is an independent risk factor for VAP in trauma, and the odds ratio is significantly higher (3.34-4.41) than in published studies of other types of ICU patients (1.89). To reduce the incidence of VAP, all efforts to reduce the transfusion of blood products to trauma patients should be implemented.

Packed Red Blood Cell Transfusion in the Intensive Care Unit: Limitations and Consequences

• Objective To review the literature on the limitations and consequences of packed red blood cell transfusions, with particular attention to critically ill patients.

• Methods The PubMed database of the National Library of Medicine was searched to find published articles on the indications, clinical utility, limitations, and consequences of red blood cell transfusion, especially in critically ill patients.

• Results Several dozen papers were reviewed, including case series, meta-analyses, and retrospective and prospective studies evaluating the physiological effects, clinical efficacy, and consequences and complications of transfusion of packed red blood cells. Most available data indicate that packed red blood cells have a very limited ability to augment oxygen delivery to tissues. In addition, the overwhelming preponderance of data accumulated in the past decade indicate that patients receiving such transfusions have significantly poorer outcomes than do patients not receiving such transfusions, as measured by a variety of parameters including, but not limited to, death and infection.

• Conclusions According to the available data, transfusion of packed red blood cells should be reserved only for situations in which clear physiological indicators for transfusion are present.

Indications for Blood Transfusion in Cardiac Surgery

In addition to its life-saving effect in hemorrhagic shock, transfusion of allogenic packed red blood cells can be beneficial in situations where a critically low hematocrit is contributing to a state of oxygen-supply dependency. These benefits are countered by the risks of transfusion-associated lung injury, transfusion-associated immunomodulation, and cellular hypoxia after RBC transfusion. The critical hematocrit is patient and organ specific, and varies intraoperatively according to the duration and temperature of bypass, as well as for a variable postoperative period. Future randomized studies must prospectively evaluate regional indicators of tissue oxygenation in transfusion algorithms.

Microbiologically documented nosocomial infections after coronary artery bypass surgery without cardiopulmonary bypass

OBJECTIVE

This study was undertaken to evaluate the frequency, characteristics, and risk factors of microbiologically documented nosocomial infections after off-pump coronary artery bypass grafting.

METHODS

A prospective cohort study was performed at Henry Dunant Hospital, Athens, Greece. It included all adult patients who underwent coronary artery bypass grafting with no valve surgery and without the use of cardiopulmonary bypass during a period of 3 years. Case patients were those with development of microbiologically documented nosocomial infections. Various variables were examined as possible risk factors for nosocomial infections.

RESULTS

Twenty-one of 782 studied patients (2.7%) acquired 26 microbiologically documented nosocomial infections after off-pump coronary artery bypass grafting. Eight of 782 studied patients had pneumonia (1.02%), 7 of 782 (0.90%) had bacteremia, 4 of 782 (0.51%) had superficial wound infection at the sternotomy site, 4 of 782 (0.51%) had urinary tract infection, 2 of 782 (0.26%) had mediastinitis, and 1 of 782 (0.13%) had pressure sore infection. Twenty-one infections were monomicrobial, whereas 5 were polymicrobial. All polymicrobial infections were wound infections. There was a statistically significant difference in mortality between patients with and without nosocomial infection (23.8% vs 1.2%, P < .001). Clinical response of the infection to the treatment administered was observed in 21 of 26 episodes (80.8%) in 21 patients. A backward stepwise multivariable logistic regression model showed that independent risk factors (P < .05) associated with development of microbiologically documented nosocomial infection were arterial hypertension, previous vascular surgery, urgent operation, postoperative atrial fibrillation, number of inotropes used during and after operation, transfusion of fresh-frozen plasma during the intensive care unit stay, and intensive care unit stay until development of infection.

CONCLUSION

Nosocomial infection after off-pump coronary artery bypass grafting is an uncommon but potentially life-threatening complication. The identification of independent risk factors, including arterial hypertension, associated with development of postoperative infection may help in the development of clinical strategies for the prevention, early diagnosis, and treatment of these infections.