Relationship of seizure duration to antidepressant efficacy in electroconvulsive therapy

BACKGROUND: Aprotinin and epsilon-aminocaproic acid are routinely used to reduce bleeding during cardiac surgery. The marked difference in average wholesale cost between these two drug therapies (aprotinin, $1,080 vs. epsilon-aminocaproic acid, $11) has generated significant controversy regarding their relative efficacies and costs. METHODS: In a multicenter, randomized, prospective, blinded trial, patients having repeated cardiac surgery received either a high-dose regimen of aprotinin (total dose, 6 x 10(6) kallikrein inactivator units) or epsilon-aminocaproic acid (total dose, 270 mg/kg). RESULTS: Two hundred four patients were studied. Overall (data are median [25th-75th percentiles]), aprotinin-treated patients had less postoperative thoracic drainage (511 ml [383-805 ml] vs. 655 ml [464-1,045 ml]; P = 0.016) and received fewer platelet transfusions (0 [range, 0-1] vs. 1 [range, 0-2]; P = 0.036). The surgical field was more likely to be considered free of bleeding in aprotinin-treated patients (44% vs. 26%; P = 0.012). No differences, however, were seen in allogeneic erythrocyte transfusions or in the time required for chest closure. Overall, direct and indirect bleeding-related costs were greater in aprotinin- than in epsilon-aminocaproic acid-treated patients ($1,813 [$1,476-2,605] vs. $1,088 [range, $511-2,057]; P = 0.0001). This difference in cost per case varied in magnitude among sites but not in direction. CONCLUSIONS: Aprotinin was more effective than epsilon-aminocaproic acid at decreasing bleeding and platelet transfusions. Epsilon-aminocaproic acid, however, was the more cost-effective therapy over a broad range of estimates for bleeding-related costs in patients undergoing repeated cardiac surgery. A cost-benefit analysis using the lower cost of half-dose aprotinin ($540) still resulted in a significant cost advantage using epsilon-aminocaproic therapy (P = 0.022).     

Aprotinin does not decrease early graft patency after coronary artery bypass grafting despite reducing postoperative bleeding and use of donated blood

Forty-five male patients with planned coronary artery bypass operation were randomized in a double blind fashion to receive either 6 million kallikrein inactivator units of aprotinin (high-dose group), 2 million kallikrein inactivator units of aprotinin (low-dose group), or placebo (control group). Postoperative bleeding was significantly decreased in both aprotinin groups in comparison to that in the control group (590 ml [290 to 1800 ml] high-dose group and 650 ml [280 to 1900 ml] low-dose group versus 920 ml (350 to 2700 ml) control group, p < 0.001). There was no difference between the two aprotinin groups. The need for postoperative blood transfusion was significantly lower in the aprotinin groups (1.46 [0 to 4] blood units high-dose group and 1.65 [0 to 5] blood units low-dose group versus 2.43 [0 to 7] blood units control group, p < 0.05). All patients underwent coronary angiography between the seventh and twelfth postoperative day. No difference was found among the three groups in patency of vein grafts-93.8% in the high-dose group, 94.5% in the low-dose groups, and 93.3% in the control group. Therefore, aprotinin significantly reduced postoperative bleeding and transfusion requirement after coronary artery bypass grafting without influencing early graft patency.     

Aprotinin and recombinant human erythropoietin reduce the need for homologous blood transfusion in cardiac surgery

The effects of low dose aprotinin (Trasylol) and preoperative administration of recombinant human erythropoietin (EPO) were evaluated in 144 patients undergoing cardiopulmonary bypass divided into four groups. Group I (n = 43) received a subcutaneous administration of EPO (18,000 U) one week before operation and intraoperative administration of low-dose aprotinin (mean; 1.38 +/- 0.26 x 10(6) kallikrein inactivator units; KIU) from extracorporeal circulation, group II (n = 39) received only preoperative administration of EPO, group III (n = 28) received only intraoperative administration of low-dose aprotinin (mean; 1.46 +/- 0.25 x 10(6) KIU), and group IV (n = 34) were not administered either drug. Compared with group IV, the intraoperative blood loss was significantly lower in group I (p < 0.01), and in group II or III (p < 0.05). The postoperative drainage in 24 hours was significantly lower in groups I and III receiving aprotinin than in the other groups. The mean volume of total homologous blood transfusion and the percentage of cases not requiring a homologous blood transfusion in each group was, respectively, 74 +/- 235 ml and 88.4% in group I, 282 +/- 1289 ml and 87.2% in group II, 414 +/- 584 ml and 60.7% in group III, and 976 +/- 1931 ml and 44.1% in group IV. Significant differences were recognized between group I and group IV (p < 0.05). These findings indicate that when used in combination, both drugs reduce blood loss and the need for a homologous blood transfusion more effectively than either drug alone.     

Aprotinin prolongs activated and nonactivated whole blood clotting time and potentiates the effect of heparin in vitro

This study was designed to evaluate the effect of aprotinin on activated versus nonactivated whole blood clotting time using two different on-site methods and to quantify these anticoagulant properties when compared to heparin in a controlled, in vitro environment. Blood specimens were obtained prior to heparin administration from 56 patients undergoing cardiac surgery. Specimens obtained from the first consecutive 20 patients were mixed with either normal saline (NS) or aprotinin (400 kallikrein inhibiting units (KIU)/mL), inserted into Hemochron tubes containing either NS or heparin (0.3 or 0.6 U/mL) and then used to measure celite-activated (celite ACT) and nonactivated whole blood clotting time (WBCT1) using four Hemochron instruments. Accordingly, specimens obtained from the second consecutive 20 patients were mixed with either NS or aprotinin, inserted into Automated Clot Timer cartridges containing either NS or heparin (0.06, 0.13, or 0.25 U/mL) and then used to measure kaolin-activated (kaolin ACT) or nonactivated whole blood clotting times (WBCT2) using four Automated Clot Timer instruments. Specimens obtained from the last 16 patients were mixed with either incrementally larger doses of aprotinin (0, 100, 200, 300, or 400 KIU/mL) or heparin (0, 0.12, 0.24, 0.36, 0.48, or 0.72 U/mL) and were then used for measurement of whole blood clotting time (WBCT2) using six Automated Clot Timer instruments. Aprotinin significantly prolonged activated or nonactivated whole blood clotting time and potentiated the prolongation of whole blood clotting time by heparin. The linear relationship between whole blood clotting time and either heparin concentration (WBCT2 = H x 357 + 280, mean adjusted r2 = 0.88) or aprotinin concentration (WBCT2 = A x 0.97 + 300, mean adjusted r2 = 0.94) was variable among patients. On average, 200 KIU/mL of aprotinin prolonged WBCT2 to the same extent as 0.69 +/- 0.28 U/mL of heparin using linear regression models within each patient. Aprotinin significantly prolongs activated or nonactivated whole blood clotting time measurements in a dose-dependent manner. Since prolongation of whole blood clotting time by heparin is potentiated by aprotinin in vitro, aprotinin's anticoagulant properties may in part account for the prolonged celite activated clotting time values observed in the presence of aprotinin.     

Analyses of coronary graft patency after aprotinin use: results from the International Multicenter Aprotinin Graft Patency Experience (IMAGE) trial

OBJECTIVE: We examined the effects of aprotinin on graft patency, prevalence of myocardial infarction, and blood loss in patients undergoing primary coronary surgery with cardiopulmonary bypass. METHODS: Patients from 13 international sites were randomized to receive intraoperative aprotinin (n = 436) or placebo (n = 434). Graft angiography was obtained a mean of 10.8 days after the operation. Electrocardiograms, cardiac enzymes, and blood loss and replacement were evaluated. RESULTS: In 796 assessable patients, aprotinin reduced thoracic drainage volume by 43% (P < .0001) and requirement for red blood cell administration by 49% (P < .0001). Among 703 patients with assessable saphenous vein grafts, occlusions occurred in 15.4% of aprotinin-treated patients and 10.9% of patients receiving placebo (P = .03). After we had adjusted for risk factors associated with vein graft occlusion, the aprotinin versus placebo risk ratio decreased from 1.7 to 1.05 (90% confidence interval, 0.6 to 1.8). These factors included female gender, lack of prior aspirin therapy, small and poor distal vessel quality, and possibly use of aprotinin-treated blood as excised vein perfusate. At United States sites, patients had characteristics more favorable for graft patency, and occlusions occurred in 9.4% of the aprotinin group and 9.5% of the placebo group (P = .72). At Danish and Israeli sites, where patients had more adverse characteristics, occlusions occurred in 23.0% of aprotinin- and 12.4% of placebo-treated patients (P = .01). Aprotinin did not affect the occurrence of myocardial infarction (aprotinin: 2.9%; placebo: 3.8%) or mortality (aprotinin: 1.4%; placebo: 1.6%). CONCLUSIONS: In this study, the probability of early vein graft occlusion was increased by aprotinin, but this outcome was promoted by multiple risk factors for graft occlusion.     

Mechanics of avian fibrous periosteum: tensile and adhesion properties during growth

Aprotinin is a proteinase inhibitor that reduces blood loss in total hip arthroplasty when administered in large doses. Little is known about the capability of smaller doses of aprotinin in reducing blood loss and transfusion needs in this surgical setting. We reviewed the medical records of 372 patients who had undergone unilateral primary total hip arthroplasty under general anaesthesia during a 6-year period (1989 to 1994) at our institution. Successively, 193 patients had and 179 patients had not received aprotinin in a dose of 20,000 kallikrein inhibitor units per kilogram body weight intravenously before surgery. Neither the volume of red blood cells lost nor that of red blood cells transfused during hospitalization differed significantly between the patients who had and those who had not received aprotinin (520 +/- 406 vs. 549 +/- 394 mL and 463 +/- 379 vs. 475 +/- 367 mL; P = 0.49 and P = 0.76 respectively). These results suggest that small-dose aprotinin was not effective in reducing blood loss and transfusion needs in patients undergoing unilateral primary total hip replacement.     

Aprotinin reduces homologous blood transfusions when pediatric cardiac surgery must be redone

The hemostatic effect of aprotinin in pediatric cardiac surgery is controversial. This study demonstrated the usefulness of aprotinin in cases undergoing additional surgery. In a retrospective study, three groups of children were investigated. In group I (n = 10), no aprotinin or Cell saver was used (control). In group II (n = 12), Cell saver was used intraoperatively. In group III (n = 14), aprotinin 30,000 KIU/kg was added to the prime of cardiopulmonary bypass, and another 10,000 KIU/kg was given every hour during extracorporeal circulation. Both blood loss and use of homologous blood during operation were significantly (p < 0.01) reduced in group III compared to those in the other two groups. In group III, blood loss both 12 and 48 hours postoperatively were one-third less than those in group I (no significant difference). The use of homologous blood 48 hours postoperatively was significantly reduced in group III compared to that in group I (p < 0.01) or group II (p < 0.05). We conclude that aprotinin administration during cardiopulmonary bypass reduced blood loss and homologous blood requirements both operatively and postoperatively when pediatric cardiac surgery must be redone.     

Intraoperative heparinisation, blood loss and myocardial infarction during aortic aneurysm surgery: a Joint Vascular Research Group study

OBJECTIVES: The primary aim of this prospective multi-centre study involving patients undergoing elective abdominal aortic aneurysm (AAA) surgery was to investigate the relationship between intraoperative intravenous heparinisation, blood loss during surgery and thrombotic complications. METHODS: Two hundred and eighty-four patients were randomised to receive intravenous heparin (n = 145) or no heparin (n = 139). Groups were evenly matched for age, sex, weight, aneurysm size, haemoglobin concentration, platelet counts and distal occlusive disease measured by ankle/brachial systolic pressure. RESULTS: There were no statistically significant differences in blood loss (median 1400 ml vs. 1500 ml; z = 0.02, p = 0.98, 95% C.I. = -200 to 200), blood transfused (4.0 units vs. 4.0 units; z = 1.09, p = 0.28, 95% C.I. = -1 to 0) or distal thrombosis between the two groups. However, analysis of the clinical outcome revealed that 5.7% of the non-heparin group but only 1.4% of the heparinised patients suffered a fatal perioperative myocardial infarction (MI); p < 0.05. All MI, including non fatal events, affected 8.5% and 2% respectively (p = 0.02). CONCLUSIONS: Heparin does not increase blood loss or the need for blood transfusion during surgery. Heparin is not necessary to prevent distal thrombosis when the aorta is cross clamped. The results of the study are consistent with the known mechanisms leading to intraoperative MI and strategies for its prevention. Intravenous heparin, given before aortic cross clamping, is an important prophylaxic against perioperative MI in relation to AAA surgery.     

The prophylactic effect of aprotinin on intraoperative bleeding in liver transplantation: a randomized clinical study

Fibrinolysis has been recognized as an important cause of intraoperative bleeding during orthotopic liver transplantation (OLT). Several investigators have used prophylactic administration of aprotinin in patients to inhibit fibrinolysis and to decrease transfusion requirements, morbidity, and mortality. Nevertheless, the role of aprotinin in this situation is not yet clear. The goal of this study was to determine the effects of prophylactic administration of aprotinin on intraoperative bleeding and blood requirements, and on hemostatic changes during OLT. Eighty consecutive patients were included in a double-blind, prospective study and were randomized in two groups. In group A (n = 39), an initial dose of 2 x 10(6) kallikrein inactivator units (KIU) of aprotinin was administered in the induction of anesthesia followed by infusion of 5 x 10(5) KIU/h until the end of the procedure. The control group (n = 41) received an identical volume of saline solution. The majority of the operations were performed with vena cava preservation (piggy-back technique) without venovenous bypass. During the anhepatic phase, a significant increase in levels of tissue plasminogen activator, thrombin-antithrombin complexes (TAT) and D-dimers (DD) was noted in both groups. A significant increment of TAT was observed in group A during reperfusion. The remaining hemostatic parameters were similar in both groups. Intraoperative requirements of packed red cells, fresh-frozen plasma (FFP), platelets, and cryoprecipitate were similar in the two groups. Our results suggest that prophylactic administration of aprotinin is not useful in reducing bleeding and blood product requirements during OLT.     

Value of pre-operative embolization in surgery for nasopharyngeal angiofibroma

The value of embolization in surgery for nasopharyngeal angiofibroma is a controversial matter. We analysed retrospectively the results of surgical treatment in ten patients with a nasopharyngeal angiofibroma, the last five of whom underwent pre-operative embolization with Gelfoam. Embolization reduced the intraoperative blood loss at primary surgery from an average of 1510 ml in the non-embolized patients to 510 ml in the embolized patients and transfusions from an average of 4.4 units to none. Seven reoperations were performed on four non-embolized patients on account of tumour recurrence, while no recurrences were diagnosed among the pre-operatively embolized patients. Blood loss in the reoperations averaged 4065 ml, and transfusions 7.1 units. The results indicate that embolization is effective in reducing intraoperative blood loss and contributes to improved surgical results. We recommend it as a routine pre-operative adjunct to surgery for nasopharyngeal angiofibroma.     

Clinical and experimental studies of intraoperative autotransfusion using a new filtration device

The Haemocell S-350 device has recently been introduced for intraoperative autotransfusion. The system uses a novel membrane filter to process shed blood. In the first part of this study a 0.2-micron pore size filter was used in a randomized trial comparing the use of autotransfusion (n = 8) with bank blood controls (n = 9) during aortic reconstruction. This part of the trial was abandoned because of unexpected non-surgical bleeding. Bank blood requirements fell from a median of 3.0 (range 0.0-9.0) units to 1.5 (range 0.0-7.0) units when autotransfusion was used, but these patients had a greater perioperative blood loss (1791 (range 932-3104) versus 1140 (range 440-3840) ml). There was evidence of postoperative heparin excess with an activated partial thromboplastin time ratio of 1.3 (range 0.9-3.0) versus 1.0 (range 1.0-1.2) in controls and an activated clotting time of 206 (range 143-280) versus 137 (range 107-142) s. This was confirmed by raised plasma heparin levels and a prolonged thrombin time normalized by protamine. To improve performance a 0.6-micron pore size filter was studied in ten patients. Filtration efficiency doubled from 19 to 38 per cent. Electron micrographs demonstrated better filter clearance, but 44 per cent of the original concentration of heparin remained in the reinfusate. The S-350 device may be an attractive alternative to centrifugation for intraoperative autotransfusion but, until efficiency is improved, it should only be used for cardiovascular surgery when excess heparin can be reversed with protamine.     

The effects of perioperative blood salvage and autologous blood donation on transfusion requirements in scoliosis surgery

Fifty consecutive cases of surgical instrumentation and fusion for adolescent idiopathic scoliosis were prospectively studied to test the hypothesis that the use of predonated autologous blood combined with judicious perioperative blood salvage could decrease the amount of homologous blood needed. All cases had posterior instrumentation and fusion. Nineteen patients had their rib prominence resected with an average of 4.8 ribs per patient. Our protocol called for perioperative blood salvage with the cell saver and reinfusion of postoperative drained blood if more than 300 ml were drained in 4 hours. Two units of predonated autologous blood was made available. Hypotensive anesthesia and meticulous hemostasis kept the blood loss to a minimum. The average total blood loss was 1,055 ml. Blood loss per segment was 91 ml with an average of 11 segments fused per patient. Patients with rib resection had a blood loss of 1,105 ml, while those without had a blood loss of 955 ml. The cell saver blood returned per case was 391 ml with the hematocrit of the product averaging 46%. Twelve patients were reinfused an average of 300 ml of the postoperative drained blood. The predonated autologous blood was used as part of the intraoperative fluid management. In no patient was homologous blood needed. The average starting hematocrit was 35.6%, with the hematocrit at discharge (seventh day) being 32.4%. There were no complications or blood transfusion reactions. Our results suggest that judicious perioperative blood management may decrease the need for homologous blood transfusion in selected posterior idiopathic scoliosis surgery.     

Fibrinolysis-adjusted perioperative low-dose aprotinin reduces blood loss in bypass operations

BACKGROUND: Postoperative bleeding still remains a serious problem in bypass surgery. This study evaluated fibrinolysis and perioperative low-dose antifibrinolytic regimens adjusted to the time course of fibrinolysis. METHODS: In a prospective, randomized study of 42 patients undergoing bypass grafting, patients received low-dose aprotinin (group A; n = 14) or low-dose tranexamic acid (group TA; n = 14) intraoperatively and postoperatively, respectively, with no antifibrinolytics for comparison (group C; n = 14). Parameters of procoagulation, fibrinolysis, and activated factor VII were measured preoperatively, intraoperatively, and postoperatively. Blood loss was determined up to 24 hours. RESULTS: The level of thrombin-antithrombin III complex was significantly decreased postoperatively in the treatment groups (group A and TA versus C: 25 +/- 14 and 19 +/- 10 microg/L, respectively, versus 40 +/- 21 microg/L; p < 0.05). Levels of plasmin-antiplasmin complexes were significantly decreased postoperatively in group A (607 +/- 231 microg/L) versus group C (825 +/- 225 microg/L) (p < 0.05) but were increased in group TA (1,145 +/- 394 microg/L) versus group C (p < 0.05). At all times intraoperatively and postoperatively, levels of D-dimers were significantly decreased in group A and group TA versus control (p < 0.001), indicating that fibrinolysis persists after the operation. Intraoperatively, the factor VIIa level decreased significantly in group A (20 +/- 8 mU/mL) versus group C (31 +/- 15 mU/mL) (p < 0.05), but not in group TA (32 +/- 15 mU/mL). Blood loss was significantly lower in group A (135 +/- 37 mL) and group TA (155 +/- 71 mL) versus group C (354 +/- 170 mL) (p < 0.001). CONCLUSIONS: This low-dose aprotinin regimen adjusted to perioperative fibrinolysis reduces blood loss significantly in coronary bypass grafting. For further progress in this subject, clinical investigations of individual fibrinolysis-adjusted antifibrinolytic treatment seems warranted.     

Aprotinin and deep hypothermic circulatory arrest: there are no benefits even when appropriate amounts of heparin are given

OBJECTIVE: To evaluate retrospectively the effect of 'high-dose' aprotinin on blood losses, donor blood requirements and morbid events on patients undergoing ascending aorta and/or aortic arch procedures with the employ of deep hypothermic circulatory arrest (HCA). METHODS: During the period 1987-1994, 39 patients underwent a thoracic aorta procedure with the employ of circulatory arrest; of these 18 (46.2%) were operated on during the period 1990-1994 and were given aprotinin intraoperatively following the 'high-dose' protocol (group I), while 21 (53.8%) who underwent surgery during the years 1987-1989, did not receive intraoperative aprotinin and served as historical controls (group II). Twenty-seven (69.2%) patients were male, 18 (46.2%) were operated on on an emergency basis, 15 (38.5%) were acute type A dissections, and two (5.1%) were redo-operations. Circulatory arrest times were not significantly different between the two groups (40 +/- 4 (S.E.) group I vs. 43 +/- 4 min group II, P = 0.62) likewise cardiopulmonary bypass (CPB) times (181 +/- 9 vs. 201 +/- 20 mm, P = 0.74) and the amount of heparin administered (32056 +/- 1435 vs. 31 691 +/- 1935 IU, P = 0.56). RESULTS: Postoperative blood loss was comparable between the two groups (1213 +/- 243 (median 850) group I vs. 1528 +/- 377 (median 880) ml group II, P = 0.87), as well as the number of units of donor blood transfused (9.4 +/- 3.0 (median 6) vs. 9.9 +/- 3.6, (median 5) P = 0.87), and revisions for bleeding (2/18, 11.1% vs. 3/21, 14.3%, P = 0.77). In-hospital mortality rate was not statistically different (5/18, 27.7% group I vs. 6/21, 28.6% group II, P = 0.92). There were no significant differences between the two groups in myocardial infarction (2/18, 11.1% vs. 0/21, 0%, P = 0.21), and postoperative renal failure rates (3/18, 16.7% vs. 2/21, 9.5%, P = 0.65). On the other hand, there was a trend towards an increased incidence of permanent neurological deficit (5/18, 27.7% group I vs. 1/21, 4.8% group II, P = 0.07) and towards a more complicated postoperative course (perioperative renal failure and/or myocardial infarction and/or neurological deficit either transient or permanent) (8/18, 44.4% group I vs. 4/21, 19% group II, P = 0.09) in group I patients. Forward stepwise logistic regression analysis, performed on the whole group of patients, identified chronic obstructive pulmonary disease (P = 0.010, Odds ratio (OR) = 5.7), aprotinin use (P = 0.017, OR = 5.1), and the number of units of blood collected intraoperatively by the cellsaver (P = 0.045, OR = 1.3/unit) as independent predictors of complicated postoperative course in the whole group of patients. CPB time (P = 0.040, OR = 1.032/min), circulatory arrest time (P = 0.053, OR = 1.22/min), and overall donor blood units transfused (P = 0.067, OR = 1.37/unit) emerged as independent risk factors for in-hospital mortality at multivariate analysis. CONCLUSIONS: Even when appropriate amounts of heparin are administered, 'high-dose' aprotinin probably is not an effective blood-sparing drug in deep HCA. Aprotinin should be employed cautiously in this clinical setting because of its possible correlation with an increased rate of postoperative morbid events.     

Effects of cardiac output on blood and tissue pH during general anesthesia with constant ventilation

We investigated the effects of cardiac output on blood and tissue pH in 106 adult patients undergoing cardiac or non-cardiac surgery under general anesthesia. After anesthetic induction, the minute ventilation volume was kept constant at 10 ml.kg-1 x 10 cycles.min-1. A pulmonary artery catheter and a nasogastric tube incorporating a tonometer were inserted. During surgery, cardiac index (CI), pH, Pco2, BE, So2 and Hb of arterial and mixed venous blood as well as gastric intramucosal pH (pHi) were measured simultaneously. Oxygen uptake index (Vo2I) and blood CO2 contents were calculated. The measurements were repeated every 10 to 20 minutes during surgery or during the prebypass period. Two patients with preoperative cardiogenic shock were excluded from data analysis because of development of severe acidosis and 624 sets of data from 104 patients were analyzed. Arterial and mixed venous pH correlated negatively with CI. Blood Pco2 and base excess (BE) correlated positively and negatively, respectively, with CI. Blood lactate concentration measured 142 times in the last 30 patients correlated positively with CI. Vo2I correlated positively with CI and Paco2 correlated positively with Vo2I. Veno-arterial differences in Pco2 and Cco2 correlated negatively with CI. Due to the difference, Caco2 correlated positively with CI, while Cvco2 did not correlate with CI. pHi correlated negatively with CI but only marginally. By multiple regression analysis, pHi was not affected significantly by CI, while it showed positive correlation with pHa, Hb, Sao2 and negative correlation with blood temperature. When cardiac output increased, blood pH decreased due to increased Pco2 and decreased BE. An increase in Paco2 might result from both an increase in Vo2 or Vco2 and decreased ventilation-to-perfusion ratio. A decrease in BE might result from increased washout of acids (e.g. lactate) from the tissue to the central circulation. In contrast to blood pH, pHi or tissue pH was not affected significantly by cardiac output unless patients were in cardiogenic shock.     

A population pharmacokinetic study of alminoprofen penetration into synovial fluid

BACKGROUND: Transfusing fresh autologous blood during cardiac surgery may improve hemostasis and decrease the need for transfusion. STUDY DESIGN AND METHODS: A prospective randomized study was performed with fresh whole blood (WB) obtained by intraoperative hemodilution (IH) and with platelet-rich plasma (PRP) obtained by perioperative apheresis from adult cardiac surgery patients. RESULTS: Seventy patients were randomly assigned to three arms: 24 to the PRP arm, 18 to the IH arm, and 28 to serve as controls. A mean of 924 +/- 130 mL of WB was collected from the IH group, and a mean of 650 +/- 124 mL of PRP was collected from the PRP group (mean, 1.42 +/- 0.74 x 10(11) platelets); these components were transfused after bypass. Preoperative measures were similar among groups. Intraoperatively, the groups did not differ in bypass time, estimated blood loss, number of transfusions, or proportion receiving transfusion(s). Postoperatively, control patients had more mediastinal drainage (736 mL vs. 476 mL [IH] and 463 mL [PRP]; p = 0.014), but there was no difference in the proportion of patients requiring red cell transfusion (p = 0.87), the hemoglobin at discharge (p = 0.20), or the length of hospitalization (p = 0.57). CONCLUSION: Although a hemostatic benefit manifested as reduced postoperative bleeding was observed, this study does not support the use of fresh blood components obtained by IH or PRP collection during low-risk cardiac surgery. Additional studies are needed to assess whether more aggressive component collection or the use of these techniques in high-risk cases may have a greater impact on clinical outcome variables, including transfusion.     

Frontal sinus mucoceles causing proptosis--two case reports

BACKGROUND: Blood requirements for Head and Neck surgical procedures have not been studied carefully. In order to set up an autotransfusion program, the blood loss and transfusion requirements should be known precisely. METHODS: The blood bank database was used to determine which Head and Neck procedures required blood transfusion during the previous 5 years. A list of 10 transfusion-associated operations was established, the records of all patients who underwent these procedures during a 5-year period were reviewed, and average the blood loss and number of units transfused determined. RESULTS: All procedures were for cancer resection. The operations were classified in 3 groups according to their transfusion probability: high (> 80%), low (< 5%) and moderate. For the moderate transfusion group, age, preoperative hemoglobin, and past medical history of cardiac and pulmonary disease were associated with higher incidence of transfusion. An average delay of 3 weeks was found between the diagnosis and the actual surgery. CONCLUSION: The transfusion requirements of Head and Neck surgical procedures could be safely met by an autotransfusion protocol, given the average delay of 3 weeks between diagnosis and surgery.     

Identification of human and rabbit cytochromes P450 1A2 as major isoforms involved in thiabendazole 5-hydroxylation

OBJECTIVE: To determine perioperative predictors of morbidity and mortality in patients > or =75 yrs of age after cardiac surgery. DESIGN: Inception cohort study. SETTING: A tertiary care, 54-bed cardiothoracic intensive care unit (ICU). PATIENTS: All patients aged > or =75 yrs admitted over a 30-month period for cardiac surgery. INTERVENTION: Collection of data on preoperative factors, operative factors, postoperative hemodynamics, and laboratory data obtained on admission and during the ICU stay. MEASUREMENTS AND MAIN RESULTS: Postoperative death, frequency rate of organ dysfunction, nosocomial infections, length of mechanical ventilation, and ICU stay were recorded. During the study period, 1,157 (14%) of 8,501 patients > or =75 yrs of age had a morbidity rate of 54% (625 of 1,157 patients) and a mortality rate of 8% (90 of 1,157 patients) after cardiac surgery. Predictors of postoperative morbidity included preoperative intraaortic balloon counterpulsation, preoperative serum bilirubin of >1.0 mg/dL, blood transfusion requirement of >10 units of red blood cells, cardiopulmonary bypass time of >120 mins (aortic cross-clamp time of >80 mins), return to operating room for surgical exploration, heart rate of >120 beats/min, requirement for inotropes and vasopressors after surgery and on admission to the ICU, and anemia beyond the second postoperative day. Predictors of postoperative mortality included preoperative cardiac shock, serum albumin of <4.0 g/dL, systemic oxygen delivery of <320 mL/ min/m2 before surgery, blood transfusion requirement of >10 units of red blood cells, cardiopulmonary bypass time of >140 mins (aortic cross-clamp time of >120 mins), subsequent return to the operating room for surgical exploration, mean arterial pressure of <60 mm Hg, heart rate of >120 beats/min, central venous pressure of >15 mm Hg, stroke volume index of <30 mL/min/m2, requirement for inotropes, arterial bicarbonate of <20 mmol/L, plasma glucose of >300 mg/dL after surgery, and anemia beyond the second postoperative day. During the study period, the study cohort used 6,859 (21.5%) ICU patient-days out of a total 31,867 ICU patient-days. Nonsurvivors used 2,023 (30%) ICU patient-days and patients with morbidity used 5,903 (86%) ICU patient-days. CONCLUSIONS: Severe underlying cardiac disease (including shock, requirement for mechanical circulatory support, hypoalbuminemia, and hepatic dysfunction), intraoperative blood loss, surgical reexploration, long ischemic times, immediate postoperative cardiovascular dysfunction, global ischemia and metabolic dysfunction, and anemia beyond the second postoperative day predicted poor outcome in the elderly after cardiac surgery. Postoperative morbidity and mortality disproportionately increased the utilization of intensive care resources in elderly patients. Future efforts should focus on preoperative selection criteria, improvement in surgical techniques, perioperative therapy to ameliorate splanchnic and global ischemia, and avoidance of anemia to improve the outcome in the elderly after cardiac surgery.     

Mortality following elective infrarenal aortic reconstruction: a Joint Vascular Research Group study

BACKGROUND: This study aimed to define the cause of death in patients undergoing elective infrarenal aortic reconstruction. METHODS: Members of the Joint Vascular Research Group who had collected details prospectively of patients undergoing elective aortic reconstruction provided information on those who died. RESULTS: Details of 3786 patients were obtained. Some 171 patients died (133 following abdominal aortic aneurysm (AAA) and 38 after aortofemoral bifurcation graft (AFBG) for occlusive disease). The mortality rate following AAA repair was 4.8 per cent, rising to 16 per cent if repair was combined with either renal or distal reconstruction (P < 0.001). Similar results were obtained with AFBG (3.4 and 11 per cent respectively, P < 0.001). The first major complication encountered was cardiac (39.8 per cent), followed by bleeding (20.5 per cent), respiratory (13.5), and gut (5.3 per cent), or limb ischaemia (6.4 per cent). Bleeding was commoner following reconstruction for aneurysm compared with that for occlusive disease (P < 0.05). Eighty-six patients (50.3 per cent) died from the first major complication. Of the remainder, 45 (53 per cent) developed multisystem organ failure (MSOF). The most commonly involved systems were cardiac, respiratory and renal. CONCLUSION: Cardiac problems were the major cause of death following infrarenal aortic reconstruction. MSOF is the 'final common pathway' in about half of the patients who survive the initial complication.     

Regulation of the Wilms'' tumour suppressor (WT1) gene by an antisense RNA: a link with genomic imprinting?

OBJECTIVE: To assess our experience with isolated iliac artery aneurysms and to assess the blood transfusion requirement in patients undergoing surgery for iliac artery aneurysms. MATERIAL AND METHODS: The case records of 12 patients who underwent 12 arterial reconstructive procedures for isolated iliac aneurysms from January 1989 to December 1995 were identified from our prospective vascular database and reviewed. Only patients with aneurysms limited to the common, external, or internal iliac arteries were included. RESULTS: Eleven patients had symptoms and rupture occurred in five patients. Aneurysmorrhaphy with graft interposition was the most common procedure. There was no perioperative mortality. The median transfusion requirement was 11 units per operation (range 1-30 units). The median intraoperative blood loss was 4700 ml (range < 500-13,000 ml). CONCLUSIONS: Isolated iliac aneurysm is a dangerous condition. A low perioperative mortality is possible only if large volumes of blood are available.