Lower Postoperative Hemoglobin Research Articles

Intraoperative Hemoglobin Levels and Transfusion Independently Predict Stroke After Cardiac Operations

Anemia has been associated with adverse cerebrovascular outcomes, particularly after cardiac operations. This study was conducted to determine if hemoglobin levels during and after cardiopulmonary bypass (CPB) predict postoperative stroke in cardiac surgical patients, independent of transfusion requirements. Individuals who had sustained a clinical postoperative stroke (cases) were matched 1:2 with controls by age, sex, surgical procedure, and year of operation. In 617 patients, conditional logistic regression was performed to analyze associations between hemoglobin levels before and after CPB, and stroke. After adjustment for potentially confounding vascular risk factors, lower hemoglobin after CPB was associated with a higher risk of stroke, even after adjustment for the amount of packed red blood cells transfused (adjusted odds ratio, 1.28; 95% confidence interval, 1.00 to 1.64, per point of lower hemoglobin level; adjusted odds ratio for stroke per higher quartile of packed red blood cells transfused in this model, 1.37; 95% confidence interval, 1.02 to 1.83). Similar associations were not found for hemoglobin concentrations preoperatively nor change in hemoglobin from before to after CPB. A post-CPB hemoglobin level below the median was associated with 37% increased odds of a postoperative stroke occurring (p = 0.02). Lower postoperative hemoglobin levels and higher intraoperative transfusion requirements are each independently associated with a higher risk of stroke. Reduced cerebral oxygen delivery due to anemia may contribute to cerebral injury after coronary artery bypass grafting.

Predictors of Duration of Unconsciousness in Patients With Coma After Cardiac Surgery

To describe clinical and brain imaging characteristics of patients who recovered and did not recover consciousness from a coma after cardiac surgery and to investigate predictors of the duration of unconsciousness in those patients who ultimately recovered consciousness. A retrospective analysis from a cohort of patients who developed coma after cardiac surgery. A single university hospital. One hundred twelve patients with postoperative stroke, encephalopathy, and/or seizures who remained in coma longer than 24 hours after cardiac surgery. None. The authors analyzed the patients' perioperative and intraoperative characteristics, laboratory values, noncontrast head computed tomography (CT) scans, and outcomes. Patients who did not recover consciousness (n = 16) were more likely to have been classified preoperatively as New York Heart Association class III/IV (p = 0.037). In patients who recovered consciousness (n = 96), only increased preoperative serum creatinine was an independent predictor of a longer duration of unconsciousness (p = 0.011). In patients who eventually recovered consciousness and had no acute findings on brain imaging, preoperative creatinine (p = 0.014), the lowest postoperative hemoglobin (p = 0.039), and surgical emergency (p = 0.045) were independent predictors of the duration of unconsciousness (p = 0.002). In patients who regained consciousness but had acute findings on brain imaging, cardiogenic shock (p = 0.012) and the insertion of an intra-aortic balloon pump before or during surgery (p = 0.025) predicted longer durations of unconsciousness (p < 0.001). In patients who ultimately recovered consciousness after being in a coma for at least 24 hours after cardiac surgery and have no abnormality on a brain CT scan, elevated preoperative serum creatinine, urgent cardiac surgery, and lower postoperative hemoglobin were correlated with an increased duration of unconsciousness.

Aprotinin and classic wound drainage are unnecessary in total hip replacement a prospective randomized trial

BackgroundClassic wound drainage is still common in hip replacement but its benefit is doubtful. The role of systemic administration of proteinase inhibitors like aprotinin to avoid perioperative blood loss is still unclear.Patients and MethodsIn a prospective randomized trial, the perioperative blood loss in alloplastic hip replacement under the influence of proteinase inhibitor (aprotinin, Trasylol®) using wound drainage as well as compression treatment alone were compared. 80 patients were prospectively randomized in 4 arms. Patients received either aprotinin or placebo during surgery as well as drainage or targeted external wound compression.ResultsObserving the "drug therapy" aprotinin had no effect on the intraor postoperative blood loss (p > 0.05), a trend to lower postoperative hemoglobin decline was found, but without significance. thrombosis occurred in neither the aprotinin nor in the placebo group. Two patients had a severe allergic drug reaction and were excluded from the study. Under "non drug therapy" with compression therapy and wound drainage a significant difference in blood loss was found (p < 0.001). The blood loss was higher under the wound drainage. There was no influence on the infection rate. Yet we could observe increased bruising under the sole external compression treatment.ConclusionThe administration of aprotinin did not achieve the desired reduction of perioperative blood loss. Hence, costs and two severe allergic drug reactions in our study represent arguments against its use in regular treatment. Furthermore, it seems that wound drainage is neglectable in hip replacement and can be substituted by a sole compression treatment.

Changes in Red Blood Cell Transfusion Practice During the Turn of the Millennium: A Retrospective Analysis of Adult Patients Undergoing Elective Open Abdominal Aortic Aneurysm Repair Using the Mayo Database

Conclusion: Change in transfusion practice, including the use of more autotransfusions and tolerance of lower perioperative hemoglobin levels, have not resulted in significant differences in perioperative morbidity or mortality in patients undergoing open abdominal aortic aneurysm (AAA) repair. Summary: The average cost of the transfusion of a red blood cell (RBC) unit is $153.68, and 14 million units of RBCs are transfused annually in the United States (Sullivan NT, et al. Transfusion 2007;47:385-94). Currently, there is also enthusiasm for reducing the number of transfused units because of reported increased morbidity and mortality with increased transfusions and reported increased infectious complications with increased transfusions. The authors sought to determine whether changes in transfusion practice during a two-decade study had any impact on perioperative morbidity and mortality in patients undergoing open elective AAA repair. The authors stratified patients undergoing open elective AAA repair into one of two transfusion-related groups. Early practice was defined as that between 1980 and 1982, and late practice was defined as between 2003 and 2006. Hemoglobin concentration and RBC transfusion were analyzed as continuous variables and compared between groups. Perioperative complications were compared, and data were age adjusted and analyses corrected for multiple comparisons. Patients in the late practice group compared with those in the early practice group had lower intraoperative (mean, 10 ± 1.4 vs 11.5 ± 1.5 g/dL), postoperative (mean, 11.9 ± 1.4 vs 13.4 ± 1.5 g/dL), and discharge hemoglobin levels (mean, 10.8 ± 1.2 vs. 12.5 ± 1.5 g/dL; P < .0001 for each variable). Fewer patients in the late practice group received intraoperative allogenic transfusions (46% vs 99%, P < .0001). There were also fewer total allogenic units transfused in the late practice group (mean, 1.7 vs 4.3, P < .0001). No patients in the early practice group had intraoperative autotransfusions, whereas intraoperative autotransfusions were used in 97% of the late practice patients (P < .0001). The incidence of perioperative morbidity and mortality was 40% (n = 119) in the late practice group and 35% (n = 106) in the early practice group (P = .27). Comment: RBC transfusion is associated with worse outcomes in cardiac surgery patients and in patients experiencing acute coronary syndrome (Murphy GJ, et al. Circulation 2007;116:2544-52; and Rao SV. JAMA 2004;292:1555-62). However, a randomized trial in critically ill patients comparing liberal vs conservative RBC transfusion found no difference in survival with the two treatment strategies (Hebert PC, et al. N Engl J Med 1999;340:409-47). The current study also found no difference in major morbidity or mortality in patients undergoing AAA repair with respect to a changing transfusion policy using more conservative thresholds for transfusion. However, the patients did no worse, and given the expense occurred with each unit transfused, a more conservative policy for patients undergoing open AAA repair is at least indicated financially if not medically.

Atrial flutter after non-congenital cardiac surgery: Incidence, predictors and outcome

BackgroundAtrial arrhythmias (AAs) occur frequently after cardiac surgery. However, most authors do not differentiate postoperative atrial fibrillation (AF) from atrial flutter (AFL). Our study sought to investigate the incidence and predictors of AFL following non-congenital cardiac surgery, and the long-term outcome of this arrhythmia. Methods and resultsWe conducted an observational, retrospective, single-centre study. Among 821 patients in sinus rhythm (SR) before non-congenital cardiac surgery, AFL occurred in 42 patients (5.1%) and AF in 77 (9.4%). Independent predictors of AAs were older age (odds ratio (OR): 1.06, 95% confidence interval (CI): 1.01–1.11, p=0.02), low postoperative hemoglobin level (OR: 0.43, CI: 0.29–0.63, p<0.0001) and long cross-clamp time (OR: 1.02, CI: 1.002–1.037, p=0.03). Compared to AF patients, those with AFL were younger (67±10 versus 72±8years, p=0.005) and less likely to have valve surgery (57% versus 76%, p=0.03). After conversion to SR, of 41/42 patients with AFL, 5 (12%) developed AFL and 5 (12%) had AF within a mean follow-up of 9.6±8.4months: only 32% of patients were on long-term antiarrhythmic therapy and 5% had radiofrequency ablation of AFL in the early postoperative period. ConclusionAFL following non-congenital cardiac surgery is not frequent. Compared to patients in AF, those with AFL are younger and less likely to have valve surgery. After conversion of AFL to SR, recurrence rate of AAs is relatively low. Therefore, AFL occurring in this setting does not require systematic catheter ablation in the postoperative period.

On admission haemoglobin in patients with hip fracture

Several authors have identified on admission haemoglobin level as the most useful predictor of transfusion risk in patients with a hip fracture. A low postoperative haemoglobin unexplained by perioperative blood loss is not uncommon in these patients. The drop in haemoglobin after re-hydration prior to surgery should depend not only on the degree of dehydration but also on the amount of blood lost in the fracture. We could find no study in the English literature estimating the magnitude of this fall in haemoglobin after re-hydration prior to surgery. We conducted a prospective study to estimate the magnitude of fall in haemoglobin after re-hydration prior to surgery by repeating the full blood count after at least 12 h of preoperative fluid resuscitation in 127 patients with hip fracture (75 consecutive at one centre and 52 consecutive at another). The average preoperative drop in haemoglobin was 2.23 gram/decilitre (g/dL) ( p-value = 0.00) in subtrochanteric fractures, 1.1 g/dL ( p-value = 0.001) in intertrochanteric fractures and 0.7 g/dL ( p-value = 0.02) in intracapsular fractures. Fifteen patients with a haemoglobin level >9 g/dL on admission were found to have a haemoglobin level <9 g/dL on repeat test and were prevented from going to theatre without arrangements for perioperative transfusion during this study. Their predicted average postoperative haemoglobin without perioperative blood transfusion was calculated to be 6.5 g/dL. The on admission haemoglobin level was found to be falsely reassuring and could lead to a very low postoperative haemoglobin level. This could prove to be dangerous for many patients especially if remains undetected for several hours. We recommend that all patients with subtrochanteric fractures, and all patients with intertrochanteric or intracapsular fractures with a haemoglobin of less than 12 g/dL on admission have a repeat haemoglobin level performed prior to their surgery.

Alternative Procedures for Reducing Allogeneic Blood Transfusion in Elective Orthopedic Surgery

Perioperative blood loss is a major problem in elective orthopedic surgery. Allogeneic transfusion is the standard treatment for perioperative blood loss resulting in low postoperative hemoglobin, but it has a number of well-recognized risks, complications, and costs. Alternatives to allogeneic blood transfusion include preoperative autologous donation and intraoperative salvage with postoperative autotransfusion. Orthopedic surgeons are often unaware of the different pre- and intraoperative possibilities of reducing blood loss and leave the management of coagulation and use of blood products completely to the anesthesiologists. The goal of this review is to compare alternatives to allogeneic blood transfusion from an orthopedic and anesthesia point of view focusing on estimated costs and acceptance by both parties.

Risk factors for late extubation after coronary artery bypass grafting

To evaluate the independent risk factors for late extubation after coronary artery bypass grafting (CABG). Preoperative, intraoperative, and postoperative characteristics of patients undergoing isolated CABG between June 2005 and June 2008 at the Tongji Hospital were retrospectively analyzed. Elapsed time between CABG and extubation of more than 8hours was defined as late extubation. The incidence of late extubation after CABG was 69.23% (288/416). Through univariate and logistic regression analysis, the independent risk factors for late extubation after CABG were older age (odds ratio [OR]=4.804), duration of cardiopulmonary bypass (OR=2.426), perioperative use of intra-aortic balloon pump (OR=1.451), preoperative arterial oxygen partial pressure (OR=.204), and postoperative hemoglobin level (OR=.793). Older age, prolonged cardiopulmonary bypass time, perioperative intra-aortic balloon pump requirement, low preoperative arterial oxygen partial pressure, and low postoperative hemoglobin level were identified as the 5 independent risk factors for late extubation after CABG.

The Effect of Gain in Total Body Water on Haemoglobin Concentration and Body Weight Following Cardiac Surgery

Haemodilution contributes to a low post-operative haemoglobin concentration in cardiac surgery patients. An assessment of the degree of haemodilution could contribute to the avoidance of red cell transfusion when such an act is based simply on a haemoglobin "transfusion trigger". We have recorded post-operative change in total body water along with body weight to assess the impact of haemodilution on haemoglobin concentration. Total body water, measured by bio-electrical impedance analysis, haemoglobin and body weight were measured pre-operatively and on the 1st, 3rd, 5th and 10th post-operative days. The percentage peri-operative change in all three variables was used to examine the paired associations. Total body water and body weight underwent a fall from day 1, with both variables significantly associated up until day 10. Haemoglobin rose steadily from day 1 to 10. This rise was associated with falling total body water and body weight until day 5, but not from day 5 to 10. Following cardiac surgery, an individual's fluid state should be considered in determining a patient's need for red cell transfusion. Monitoring body weight provides a simple estimate. Such an approach may reduce the incidence of unnecessary, and potentially counterproductive, transfusion in cardiac surgery patients.

Is There a Need for Autogenous Blood Donation in Orthognathic Surgery?

The present study sought to determine the frequency of blood transfusion and to evaluate the need for autogenous blood donations in patients undergoing bimaxillary orthognathic surgery. According to an inclusion and exclusion protocol, 65 patients were selected for further analysis. Twenty-six patients donated a total of 45 units of autogenous blood; the remaining 39 patients did not. Medical records were reviewed retrospectively. Donors tended to have lower preoperative, intraoperative, and postoperative hemoglobin values, as well as lower hematocrit and leukocyte counts. Only the difference in mean preoperative leukocyte count, however, was statistically significant (donor: 6500/microl versus nondonor: 7400/microl; p = 0.021). The rate of transfusion was 2.5 percent for nondonors and 13 percent for donors of autogenous blood. Six donors had to be transfused a total of 8 units of autogenous blood, whereas only one of 39 nondonors received an allogenic blood transfusion. This difference turned out to be significant according to Fisher's exact test (p = 0.013). None of the donors received allogenic blood transfusion. In the authors' analysis, preoperative autogenous blood donation appears to be effective in reducing exposure to allogenic blood. Donors of autogenous blood, however, were transfused significantly more often than nondonors were. Neither intraoperative blood loss nor hematological values justify a preoperative donation of autogenous blood on a regular basis.

Minimizing blood transfusions in the surgical correction of coronal and metopic craniosynostosis

The current study was performed to determine the rate of allogeneic blood transfusion for coronal and metopic craniosynostosis surgery done by two experienced pediatric neurosurgeons and to identify factors associated with a need for transfusion. First operations for coronal and metopic craniosynostosis correction in children from 1996 to 2002 were reviewed retrospectively. For analysis, the primary endpoint was defined as either the receipt of a blood transfusion or a postoperative Hb level below 70 g/l, even if no blood was transfused. Univariate and multivariate analyses were done to examine the relationship of attaining the primary endpoint to extent of surgery, surgeons, surgery time, preoperative hemoglobin, craniosynostosis type, weight, and age. Thirty-two patients were operated on: 17 with unicoronal; 9 with bicoronal, and 6 with metopic craniosynostosis. Median age at operation was 7.5 months. Blood transfusion rates were 0% for unicoronal, 44% for bicoronal, and 33% for metopic synostosis operations. Logistic regression revealed that the best predictor of having a postoperative hemoglobin level of <70 g/l or receiving a blood transfusion was the extent of surgery (beta=1.59, SE(beta)=0.57). The odds of reaching the primary endpoint for extensive surgery over basic surgery was 4.9 [95%CI=(1.6,15.0)]. Once extent of surgery was accounted for in the model, no other covariates significantly improved the model. Low transfusion rates were achieved in primary operations for coronal and metopic craniosynostosis using simple intraoperative techniques and by accepting a low postoperative hemoglobin level.

Do we really need to routinely crossmatch blood before primary total knee or hip arthroplasty?

A maximum surgical blood ordering schedule may lead to wastage of valuable resources due to over-ordering of blood and/or under-utilisation. We audited the results of a group-and-save (GS) policy for primary hip (THR) and knee (TKR) arthroplasty to evaluate its safety and practicality. We conducted a retrospective review of consecutive patients attending for THR (177) or TKR (137) over a period of 8 months (phase 1). Following introduction of a limited GS policy, 205 THR and 147 TKR were reviewed prospectively over a corresponding period of 8 months (phase 2). Corresponding THR and TKR groups in each phase were comparable with respect to age, gender, length of stay, operating surgeon, pre- and lowest postoperative hemoglobin, reason for and timing of transfusion. Quantities (units) of blood requested pre- and postoperatively, transfused and returned to the blood bank, were recorded. 77 and 62% of all blood requested for THR and TKR, respectively, in phase 1 was not used. 58 and 21% of patients undergoing THR and TKR, respectively, in phase 2 underwent preoperative GS, with 92% and 100% of all blood requested being used for transfusion. Overall, the quantity of blood returned was reduced by 25% for the THR group. Transfusion rates fell by 9% and 5% for the TKR and THR groups, respectively. We found no adverse events associated with blood from a GS sample. Cost savings of 37 800 euro were calculated estimated for the study period (phase 2). For routine primary THR/TKR, GS policy is a safe procedure. Reduction in non-utilisation of blood has economic and cost-saving implications for limited healthcare resources. Having subsequently introduced a group-and-save policy for all patients undergoing routine THR/TKR, considerable savings have been identified after only 2 months.

Effects of preoperative enoxaparin versus unfractionated heparin on bleeding indices in patients undergoing coronary artery bypass grafting

Background We examined the effects of preoperative administration of enoxaparin (ENOX), a low-molecular-weight heparin, on bleeding indices and transfusion rates in patients undergoing coronary artery bypass grafting (CABG). Methods Patients undergoing isolated CABG between 1997 and 2002 who received preoperative ENOX or a continuous infusion of unfractionated heparin (UFH) were randomly divided into three groups: continuous UFH, ENOX last administered more than 12 hours before surgery (ENOX > 12), and ENOX administered less than 12 hours before surgery (ENOX < 12). Perioperative hemoglobin values, transfusion rates, and bleeding complications were compared. Results A total of 69, 58, and 34 patients comprised the UFH, ENOX > 12, and ENOX < 12 groups, respectively. Preoperative demographics and hematologic data were similar among the groups. Compared with the UFH group, the ENOX < 12 group had significantly lower postoperative hemoglobin values (9.6 ± 1.3 g/dL versus 10.4 ± 1.2 g/dL, p < 0.05), higher transfusion rates (73.5% versus 50.7%, p < 0.05), and required more total packed red cells per patient (882 ± 809 mL versus 472 ± 626 mL, p < 0.05). A nonsignificant increase was noted in the risk of returning to the operating room for bleeding in patients who had received ENOX compared with patients receiving UFH (6.5% versus 2.9%). Conclusions The preoperative use of ENOX less than 12 hours before CABG is associated with lower postoperative hemoglobin values and higher rates of transfusion than continuous UFH.

Prognostic implications of hemoglobin levels before and after surgery as well as before and after radiochemotherapy for head and neck tumors.

Several studies have shown that tumor cells may develop resistance to radiotherapy, proliferating under hypoxic conditions. Following surgery, patients may develop low hemoglobin levels, which may cause low oxygen conditions. This retrospective analysis was undertaken to determine the impact of low hemoglobin levels in patients with head and neck tumors treated with combined-modality therapy (surgery and postoperative radiochemotherapy). We studied 120 patients with mostly advanced head and neck tumors (88% stage III/IV) who had undergone macroscopically complete resections of their primary tumors and lymph node metastases. At 20-277 days after surgery (median: 51.3 days), these patients received postoperative chemoradiotherapy (56.7 Gy of radiation over 28-49 days and cisplatin 6 mg/m(2) body surface area on radiation treatment days with a cumulative dose of 96 mg/m(2)). Normal hemoglobin levels were considered to be 12 g/dl for females and 13 g/dl for males. Decreased hemoglobin levels before or after surgery and before or after chemoradiotherapy were correlated with the prognosis. Preoperatively, 99 of 114 patients (87%) had normal levels of hemoglobin compared with only 20 of 107 patients (19%) postoperatively. At the onset of radiochemotherapy, the hemoglobin levels of 82 of 116 patients (71%) were within the normal range. After radiochemotherapy, however, 62 of 114 patients (54%) had normal hemoglobin levels. Univariate analysis (Kaplan-Meier method and log-rank test) showed that patients with decreased pre- or postoperative hemoglobin levels had significantly worse locoregional control ( P=0.032 and P=0.0001, respectively) and lower overall survival ( P=0.0013 and P=0.0002, respectively) than patients with normal hemoglobin levels. The 3-year locoregional control rates in patients with preoperative hemoglobin levels that were normal, were reduced by 1-2 g/dl or were reduced by more than 3 g/dl, respectively, were 78%, 55% and 50%. Correlated with normal and diminished postoperative hemoglobin levels, the 3-year locoregional control rates were 90%, 84% and 50%, respectively. There was no correlation between prognosis and hemoglobin level at the onset or after radiochemotherapy. On multivariate analysis, only the postoperative hemoglobin level remained a prognostic factor for locoregional control ( P=0.0241) and overall survival ( P=0.0080). We conclude that low postoperative hemoglobin levels resulting from blood loss may influence the efficacy of postoperative radiochemotherapy in patients with head and neck cancer. Early intervention to raise the postoperative hemoglobin level may result in better tumor control and overall survival after combined-modality therapy.

Reduction of transfusion rates in the surgical correction of sagittal synostosis.

As public concern about the risks of blood transfusions increased in the mid-1990s, avoidance of transfusions became a goal of surgery for sagittal synostosis. This study was performed to confirm a hypothesized reduction in transfusion rates in recent years and to identify factors associated with both the need for transfusion and low postoperative levels of hemoglobin. Sagittal synostosis operations performed in children between 1986 and 1999 were reviewed retrospectively. Patients underwent a minimum of vertex strip craniectomy and parietal craniectomies. There were 118 patients whose median age at surgery was 4.2 months. The primary end point for analysis was defined as either the receipt of a blood transfusion or a postoperative level of hemoglobin less than 70 g/L. Forty-two percent of patients (95% confidence interval [CI] 31-52%) treated before 1996 and 11% of patients (95% CI 0-23%) treated from 1996 onward received blood. The reduction in the blood transfusion rate in later years was, in part, related to the acceptance of a lower postoperative hemoglobin level, often below 70 g/L. A univariate analysis showed that the only patient or surgical factors that correlated with reaching the primary end point in a statistically significant manner were the year of surgery and the extent of surgery. A logistic regression of the age and weight of the child, length of surgery time (from skin opening to skin closure), preoperative hemoglobin level, extent of surgery, and surgeon against the primary end point revealed that the best predictor of the need for a blood transfusion or the presence of a postoperative hemoglobin level lower than 70 g/L was the extent of surgery (beta = 1.4, standard error of the beta statistic = 0.44). Once the extent of surgery was accounted for in the model, no other covariates significantly improved the model. Techniques implemented to minimize blood loss since 1995 included the following: use of the Colorado needle for scalp incision, selection of the Midas Rex craniotome for cranial cuts, and application of microfibrillar collagen. Postoperative hemoglobin was allowed to decrease to 60 g/L if the child was stable hemodynamically, before blood was administered. There were no cardiovascular, wound healing, or infectious complications, and no surgeries were repeated for cosmetic reasons. Low blood transfusion rates were achieved using simple intraoperative techniques and by accepting a low level of postoperative hemoglobin.

Effect of perioperative complications on excess mortality among women after coronary artery bypass: The israeli coronary artery bypass graft study (ISCAB)

Background: Widely observed excess mortality among women after coronary artery bypass grafting is still largely unexplained, although case-mix factors have been identified. We evaluated the contribution of perioperative complications to the risk of 180-day mortality among women while adjusting for case-mix factors. Methods: This is part of a prospective, 1-year nationwide Israeli coronary artery bypass graft study of 1029 female and 3806 male patients. Deaths within 180 days were independently ascertained. Case-mix risk strata were obtained from a pooled Cox survival model (including all subjects and study variables) by using the adjusted coefficients corresponding to the case-mix factors within the model. Sex-specific mortality associated with perioperative complications was evaluated within the strata. In addition, sex-specific Cox models were constructed. Results: Higher mortality among women compared with that among men was significant within the pooled model (hazard ratio, 1.4; P =.038) and was evident early in the postoperative period. Women tended to cluster in the highest risk quartile compared with men (39.8% vs 20.9%, P <.001). However, although the incidence of perioperative complications was similar for the 2 sexes, the associated mortality for a given perioperative complication was higher among women. Sex-specific Cox models confirmed the above findings. For example, the hazard ratio for women with low postoperative hemoglobin was 6.9, whereas for men, the hazard ratio was 3.9. Conclusions: The role of perioperative factors in the excess mortality among women after coronary artery bypass grafting shifts the focus of attention from the selection of women for the operation to the in-hospital experience. Improving the outcome for women will entail efforts to prevent complications in the perioperative period.J Thorac Cardiovasc Surg 2002;123:517-24

Placenta previa: A 22-year analysis

Objective: Our purpose was to identify what anesthetic method is safer for women with a placenta previa. Study Design: We retrospectively reviewed all women with placenta previa who underwent cesarean delivery during the period January 1, 1976–December 31, 1997 at Northwestern Memorial Hospital. Results: Of 93,384 deliveries, placenta previa was found in 514 women. Identifiable trends with time included an increasing incidence of placenta previa ( r = 0.54, P < .01); cesarean hysterectomy ( r = 0.54, P < .01); placenta accreta ( r = 0.45, P < .03); and regional anesthesia ( r = 0.84, P < .0001). The mean gestational age at delivery was 35.3 ± 3.4 weeks and did not change with time. General anesthesia was used for delivery in 380 women and regional anesthesia was used for 134 women. Prior cesarean delivery and general anesthesia were independent predictors of the need for blood transfusion, but only prior cesarean delivery was a predictor of the need for hysterectomy. General anesthesia increased the estimated blood loss, was associated with a lower postoperative hemoglobin concentration, and increased the need for blood transfusion. Elective and emergent deliveries did not differ in estimated blood loss, in postoperative hemoglobin concentrations, or in the incidence of intraoperative and anesthesia complications. Regional and general anesthesia did not differ in the incidence of intraoperative and anesthesia complications. Conclusions: In women with placenta previa, general anesthesia increased intraoperative blood loss and the need for blood transfusion. Regional anesthesia appears to be a safe alternative. (Am J Obstet Gynecol 1999;180:1432-7.)

Preoperative autologous blood deposition in support of gynaecological repair procedures.

Autologous blood transfusion was evaluated in gynaecological repair procedures including abdominal/ vaginal hysterectomy with vaginal repair, post-hysterectomy vaginal suspension and fixation, uni/bilateral salpingo-oophorectomy with vaginal colpopexy and sling procedures. A total of 247 autologous units were collected from 95 patients at the regional blood centre with 1-3 units (mean 2-6 units) deposition from each patient. One hundred and ninety of all collected units were transfused (collection/transfusion ratio = 1.3). Of these patients, 86 (90.5%) received autologous blood; 12 (13%) being transfused with 1 unit, 44 (46%) with 2 units and 30 (32%) with 3 units. Two of these patients received additional homologous blood. The average preoperative haemoglobin level was 119 g L-1 and average post-operative haemoglobin level was 105 gL-1. The post-operative Hb level was used as a retrospective indicator for the requirement for blood transfusion. The results show that overall 75% of patients had post-operative haemoglobin levels < or = 110 and 33% of patients with Hb levels < 100, respectively. These results suggest that preoperative autologous blood deposition may be appropriate in the patients undergoing reconstructive gynaecological repair procedures since there was a high rate of usage of autologous blood and low post-operative haemoglobin in a significant proportion of patients.

CURRENT METHODS TO REDUCE THE ADVERSE HAEMATOLOGICAL CONSEQUENCES OF CARDIOPULMONARY BYPASS

SUMMARYBleeding remains a significant cause of morbidity after cardiac surgery and results in a major demand on blood transfusion capacity. The aetiology is multifactorial, but platelet dysfunction is the most important cause. Because of the potential risks of heterologous blood transfusion, a number of techniques have been developed to reduce its need. These can broadly be divided into three categories. First, modification of bypass methods and the use of agents such as aprotinin can reduce blood loss. Second, more use can be made of the patient's own blood through predonation of autologous blood or blood conservation techniques. Finally, transfusion policy can be modified so that a lower postoperative haemoglobin level is accepted. However, a method with which to preoperatively predict those patients who will bleed significantly remains elusive.