Biomedical subjects

B Zickmann

Publications and source records attributed to B Zickmann.

At least 55 records · Page 3Linked to original sources

PubMed1993

Influence of different glucose-insulin-potassium regimes on glucose homeostasis and hormonal response in cardiac surgery patients .

Intravenous infusion of glucose/insulin in combination with potassium (GIK) is an often used technique to improve myocardial preservation in cardiac surgery. In a randomized study in 50 patients undergoing elective aortocoronary bypass grafting with good ventricular function, the influence on glucose homeostasis and hormonal response to four different glucose/insulin regimes were compared to an untreated control: 1) 50 g of glucose mixed with 100 U of human insulin (HI/100); 2) 50 g of glucose mixed with 100 U of bovine insulin (BI/100); 3) 50 g of glucose mixed with 50 U of human insulin (HI/50); and 4) 50 g of glucose mixed with 50 U of bovine insulin (BI/50) [corrected]. Glucose/insulin were given in combination with 70 mmol of potassium 40 min before beginning the operation. In addition to blood glucose concentrations various endocrine variables were studied before, during and after cardiopulmonary bypass (CPB). Hemodynamic data (arterial blood pressure, heart rate, cardiac index, systemic vascular resistance) were similar in all five groups. Inotropic support after CPB was necessary in none of the patients. Blood glucose levels showed no differences among all GIK groups (groups 1-4) but were significantly higher than in the control patients. The incidence of severely reduced (< 50 mg/dL) or elevated blood glucose level (> 300 mg/dL) did not differ between HI- and BI-treated patients but was significantly lower in the untreated control. Insulin plasma level increased significantly after infusion of GIK with higher levels in HI- than BI-treated patients (P < 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1993

Influence of different intravascular volume therapies on platelet function in patients undergoing cardiopulmonary bypass.

The influence of four different kinds of intravascular volume replacement on platelet function was investigated in 60 patients undergoing elective aortocoronary bypass grafting using cardiopulmonary bypass (CPB). In a randomized sequence, high-molecular weight hydroxyethyl starch solution (HMW-HES, mean molecular weight [Mw] 450,000 d), low-molecular weight HES (LMW-HES, Mw 200,000 d), 3.5% gelatin or 5% albumin were infused preoperatively to double reduced filling pressure (pulmonary capillary wedge pressure [PCWP] < 5 mm Hg). Fifteen untreated patients served as a control. Platelet function was assessed by aggregometry using turbidometric technique (inductors: ADP, epinephrine, collagen). Maximum aggregation, maximum gradient of aggregation, and platelet volume were measured before, during, and after CPB until the first postoperative day. HMW-HES 840 +/- 90 mL, LMW 850 +/- 100 mL, gelatin 950 +/- 110 mL, and albumin 810 +/- 100 mL were given preoperatively. Maximum platelet aggregation (ranging from -23% to -44% relative from baseline value) and maximum gradient of platelet aggregation (ranging from -26% to -45% relative from baseline values) were reduced only in the HMW-HES patients. After CPB, aggregometry also was impaired most markedly in these patients. The other volume groups showed less reduction in platelet aggregation and were similar to the untreated control. On the first postoperative day, aggregation variables had returned almost to baseline in all patients. Platelet volume was the same among the groups within the investigation period. Postbypass blood loss was highest in the HMW-HES group (890 +/- 180 mL). There was significant (P < 0.04) correlation in this group between blood loss and change in platelet aggregation.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗

PubMed1993

Comparison of two aprotinin dosage regimens in pediatric patients having cardiac operations. Influence on platelet function and blood loss.

Only a few studies have reported on the effects of aprotinin in pediatric cardiac surgery, and the correct dose is controversial. In a prospective, randomized study, three groups of children weighing less than 20 kg were investigated. In group 1 (n = 14): aprotinin 20,000 U/kg was given after induction of anesthesia, 20,000 U/kg was added to the prime, and another 20,000 U/kg was given every hour of cardiopulmonary bypass (low-dose regimen). In group 2 (n = 14) aprotinin 35,000 U/kg was given after induction followed by an infusion of 10,000 U/kg.min until the end of the operation and 35,000 U/kg was added to the prime (high-dose regimen). In group 3 (n = 14) no aprotinin was used (control). Platelet function was evaluated by aggregometry (maximum platelet aggregation, maximum gradient of platelet aggregation) by means of turbidometric technique (inductors: adenosine diphosphate, collagen, and epinephrine) before and after cardiopulmonary bypass until the first postoperative day. Platelet aggregation was significantly reduced during and after bypass, values ranging from -29% to -54% (maximum aggregation) and -25% to -75% (maximum gradient of aggregation) with regard to baseline values. In the further postoperative course, platelet function recovered and mostly exceeded baseline values on the first postoperative day. Platelet aggregation variables were without any differences among aprotinin-treated and control patients. Blood loss was similar for all three groups and added up to approximately 28 ml/kg until the first postoperative day. The use of packed red cells was also comparable for the three groups, whereas the use of fresh frozen plasma was highest in group 1 (1680 ml until the first postoperative day). We conclude from this study that aprotinin did not improve platelet function and did nor reduce blood loss or the need for homologous blood transfusion in pediatric cardiac surgery, regardless of whether a low-dose or a high-dose regimen was used.

Aprotinin↗

PubMed1993

[Cardiac protection in heart surgery interventions by preventive drug administration before extracorporeal circulation. Studies with troponin T as a parameter for perioperative myocardial damage].

The present study was designed to test if prophylactic intravenous nifedipine or nitroglycerine could reduce myocardial damage after cardiopulmonary bypass. 45 patients scheduled for elective coronary artery bypass grafting were divided at random into three groups: Group 1: control; group 2: nifedipine (0.25 microgram/kg/min); group 3: nitroglycerine (1.5 micrograms/kg/min). Infusion period reached from the beginning of anaesthesia until crossclamp of the aorta. Myocardial damage was estimated by troponin T (TnT), CK-MB and ST-segment analysis of the ECG. TnT is a cardiospecific protein from the contractile apparatus of striated muscle cells. TnT-levels might provide a very sensitive marker of small amounts of cardiac muscle necrosis. It was tested with an ELISA/one-step sandwich-assay with streptavidin-technology [9]. Criteria for ischemia in the ST-segment analysis were (according to Smith et al. [19]): ST-depression > 1 mm from baseline or ST-elevation > 2 mm from baseline at J-point + 60 ms. Statistical interpretation was done by one- and two-factorial analyses of variance (including multivariate analyses of variance). Correlation between two variables was tested by regression analysis. A level of p < 0.05 was taken for indicating statistical significance. Biometrical data, circulation data and data from cardiopulmonary bypass were without significant differences among all groups (Tables 1 and 2). Starting from normal values (< 0.05 ng/ml) TnT significantly rose in all groups immediately after cardiopulmonary bypass and remained elevated until the forth day after operation (values between 0.4 and 0.6 microgram/ml) (Figure 1).(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗

PubMed1992

Phosphodiesterase-inhibitors enoximone and piroximone in cardiac surgery: influence on platelet count and function.

OBJECTIVE: Some phosphodiesterase (PDE)-inhibitors are believed to alter platelet count and function due to changes in intracellular cAMP. Whether newly developed (specific) PDE-inhibitors negatively influence platelet function in cardiac surgery should be investigated in a randomized study. METHODS: Eighty patients undergoing aorto-coronary bypass grafting were divided into 4 groups and received either the new PDE-III-inhibitor piroximone (group 1), the PDE-III-inhibitor enoximone (group 2), epinephrine (group 3) or no inotropic support (control). PDE-III-inhibitors were given as a bolus followed by infusion until starting of cardiopulmonary bypass (CPB). In addition to platelet count and a thrombelastogram, platelet function was assessed by aggregometry (ADP, epinephrine, collagen). Measurements were done before, during and after CPB until the 1st postoperative day. RESULTS: Platelet count and postoperative blood loss did not differ between the groups within the entire investigation period. Maximum aggregation and maximum gradient of platelet aggregation to all stimuli were not changed by either PDE-inhibitor enoximone or piroximone. CPB resulted in a significant decrease of all aggregation variables which was without differences due to treatment. Platelet aggregation recovered in the post-bypass period and exceeded baseline values on the 1st postoperative day. CONCLUSION: It is concluded that enoximone and the new PDE-III-inhibitor piroximone do not affect platelet function and can be used before CPB without risking platelet-related bleeding in cardiosurgical patients in the perioperative period.

Adenosine Triphosphate↗

PubMed1992

The effects of preoperative aspirin therapy on platelet function in cardiac surgery.

Extracorporeal circulation is known to have profound effects upon platelets. Changes in platelet function were assessed in 20 patients undergoing elective coronary artery bypass grafting (CABG) who stopped taking aspirin (100 mg per day) 5-7 days before the operation compared with 20 patients undergoing aortic valve replacement (AVR) who had never taken anticoagulants or aspirin. Platelet aggregometry was carried out using the turbidimetric technique (inducing agents: adenosine diphosphate (ADP) 1.0 and 2.0 mumol/l; collagen 4 micrograms/ml; epinephrine 25 mumol/l), and maximum aggregation as well as the maximum gradient of aggregation were monitored before, during, and after cardiopulmonary bypass (CPB) until the 1st postoperative (p.o.) day. Until the 1st p.o. day blood loss was significantly higher in the CABG (890 +/- 160 ml) than in the AVR patients (420 +/- 120 ml). A total of 8 units of packed red cells (PRC) were given in the CABG group, whereas no homologous blood was necessary in the AVR patients (P < 0.05). The aggregation variables of the CABG patients were lower than in the AVR patients as early as after the induction of anesthesia (difference in maximum aggregation ranged from 13-29%). During CPB and immediately thereafter, all aggregation variables were significantly reduced in the CABG patients (reduction in maximum aggregation ranged from -32 to -49%) and were significantly different from the platelet aggregation in the AVR patients. Five hours after CPB and on the 1st p.o. day platelet aggregation in the CABG group almost returned to baseline values, however, without reaching the values of the AVR patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1992

Effects of pulsatile and nonpulsatile perfusion mode during extracorporeal circulation--a comparative clinical study.

In a prospective randomized study with 80 male patients scheduled for aorto-coronary bypass grafting we investigated the influence of pulsatile and nonpulsatile perfusion mode on cell count (leukocytes, platelets, hematocrit), concentrations of thromboxane (TXB2), 6-keto-prostaglandin F1 alpha (6-keto-PGF1 alpha), plasma hemoglobin, PMN-elastase, complement C3a, clotting factor XII, lactate, plasmatic inhibitors (C1-INH, AT-III, alpha 2-antiplasmin), arterio-venous oxygen difference (AVDO2) and hemodynamic parameters. Changes in hematocrit were similar in both groups, whereas plasma hemoglobin concentration was significantly higher with pulsatile perfusion. Platelet count paralleled changes in hematocrit and was not influenced by the perfusion mode. Leukocyte count as well as concentrations of PMN-elastase and C3a showed a strong increase during cardiopulmonary bypass, but there were no significant differences between the two groups. Similar changes of the concentrations of TXB2 and 6-keto-PGF1 alpha were noted irrespective of the perfusion mode applied. The observed alterations in the concentrations of clotting factor XII, alpha 2-antiplasmin, AT-III and C1-INH largely paralleled hematocrit changes in either flow mode. Significant differences between the two groups were found with lactate: with nonpulsatile perfusion there was a slight but continuous increase, while with pulsatile flow lactate levels remained unchanged. There was no evidence for a better oxygen uptake (AVDO2) with pulsatile perfusion. Pulsatile perfusion seems to be advantageous to tissue perfusion, however, at the cost of a higher rate of hemolysis. We cannot confirm further salutary effects of the pulsatile perfusion mode with the 1-pump-system on cellular and humoral blood constituents.(ABSTRACT TRUNCATED AT 250 WORDS)

6-Ketoprostaglandin F1 alpha↗

PubMed1992

Transcranial Doppler sonography: effects of halothane, enflurane and isoflurane on blood flow velocity in the middle cerebral artery.

Systolic, diastolic, and mean blood flow velocity in the middle cerebral artery (Vs,mca; Vd,mca; Vm,mca) and pulsatility (Vs-Vd)/Vm of the waveform obtained were recorded in 51 patients before, during and after general anaesthesia. Transcranial Doppler (TCD) sonographic variables were measured in the awake patient and after induction of anaesthesia with thiopentone 5-6 mg kg-1. After tracheal intubation, 17 patients received 0.8% halothane and 66% nitrous oxide in oxygen for 30 min (15 min normoventilation; 15 min hyperventilation). The inspired halothane concentration was then increased to 1.6% for 45 min (15 min normoventilation; 15 min hyperventilation; 15 min normoventilation with nitrous oxide replaced by oxygen). Enflurane (1.7% for 30 min and 3.4% for 45 min) was given to another 17 patients; 17 other patients received isoflurane (1.2% and 2.4%). Mean arterial pressure (MAP), nasopharyngeal temperature, end-tidal carbon dioxide concentration, inspired and end-tidal anaesthetic agent concentrations, haemoglobin concentration, PVC and TCD variables were measured at the end of each 15 min period. After recovery from anaesthesia, TCD variables were measured again. There were no intergroup differences in changes in MAP, nasopharyngeal temperature, haemoglobin concentration and PCV. Halothane, enflurane and isoflurane at low doses and normoventilation had little influence on TCD variables compared with awake values. In large concentrations with nitrous oxide in oxygen and normoventilation, there were differences between the volatile agents. Halothane increased blood flow velocities, but enflurane and isoflurane caused little change. Hyperventilation always decreased blood flow velocities and increased pulsatility.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

PubMed1992

The role of enoximone in cardiac surgery.

After cardiopulmonary bypass (CPB), some patients may require circulatory support. This study examined the role of the phosphodiesterase-III inhibitor, enoximone, in cardiac surgery. Eighty patients selected by chance were allocated randomly to two groups: 40 patients received enoximone 1.0 mg kg-1 approximately 10 min before weaning from CPB and 40 served as a control group. Additional pharmacological therapy (adrenaline, noradrenaline, nitroglycerin) was given, when necessary, by anaesthetists who were not involved in the study. In addition to standard monitoring, skin capillary blood flow was assessed using a laser Doppler technique before, during and after CPB until 2 h after the end of the operation. In the period after bypass, cardiac index was always significantly greater in the enoximone than in the control group. Systemic and pulmonary vascular resistance were less in the enoximone-treated patients, indicating a reduction in right and left ventricular wall stress. Oxygen consumption in the enoximone patients was significantly greater after CPB, whereas intrapulmonary shunting was comparable in the two groups. In comparison with baseline values, skin capillary blood flow in the enoximone patients was always greater than that in the control group. In comparison with the control patients, significantly fewer enoximone patients needed adrenaline, and in a smaller dose, even 2 h after operation, whereas more enoximone patients required noradrenaline therapy for a short period. We conclude that the use of enoximone before weaning from CPB improved overall cardiac function, reduced the need of catecholaminergic inotropic support, and provided increased organ perfusion up to 2 h after operation.

Adult↗

PubMed1992

Endothelin plasma levels in old and young patients during open heart surgery: correlations to cardiopulmonary and endocrinology parameters.

We compared endothelin (ET) plasma levels during and after aortocoronary bypass (CPB) grafting in old and young patients. Correlations to cardiopulmonary parameters and catecholamines were tested. The study included 22 patients (11 aged greater than 70 years and 11 aged less than 55 years). Measurements were performed after induction of anesthesia (baseline), before bypass, during bypass, after patients were weaned off bypass, at the end of operation, and after 4-h intensive care (IC) treatment. ET [radioimmunoassay (RIA) technique] and catecholamines [high pressure liquid chromatography (HPLC) technique] plasma levels were determined from arterial blood samples; hemodynamics (pulmonary artery catheter), oxygen data, and laser Doppler flow were also monitored. Baseline ET plasma levels were within normal range (young, 3.1 +/- 0.9 pg/ml, old, 4.5 +/- 1.4 pg/ml). Old patients had higher values during the entire investigation period. During CPB ET plasma levels increased to a maximum immediately after patients were weaned off bypass. A significant increase (twofold to baseline) was noted during IC therapy. ET plasma levels did not correlate to catecholamine plasma levels or to hemodynamic or laser Doppler flow parameters. A significant correlation existed between ET plasma levels and oxygen consumption. Monitoring ET plasma levels appears to be of minor value in predicting circulatory changes and assessing surgical stress. Further investigations must elucidate the increase in oxygen consumption and its correlation to ET plasma level.

Aged↗

PubMed1992

Influence of five different priming solutions on platelet function in patients undergoing cardiac surgery.

The ideal choice of a priming solution of the cardiopulmonary bypass (CPB) and its influence on the hemostatic system are not clear. Addition of albumin was reported to inhibit platelet damaging by blood-surface interactions ("coating"). To explore this possibility in 60 consecutive male patients undergoing elective aortocoronary bypass grafting, five different priming solutions were randomly used: (1) 1000 mL of 5% dextrose + 1000 mL of Ringer's solution (RS) + 250 mL of 5% human albumin (HA); (2) 1850 mL of RS + 400 mL of 20% HA; (3) 1750 mL of RS + 500 mL of 10% low molecular weight hydroxyethyl starch (molecular weight average: 200,000; molar substitution ratio: 0.5); (4) 1750 mL of RS + 500 mL of 3.5% gelatin; (5) 2250 mL of RS. Platelet function was studied by aggregometry (= turbidometric technique; 1.0 and 2.0 mumol/L of adenosine diphosphate (ADP), 4 microL/mL of collagen, 25 mumol/L of epinephrine) before, during, and after CPB until the first postoperative day. Blood loss and need for homologous blood was not different between the groups. During CPB, maximum platelet aggregation induced by ADP was least compromised in group 1 and group 4. At the end of the operation ADP-induced aggregation increased in group 1 (+27%), whereas aggregation was decreased in the other priming solution groups. A significant increase in maximum aggregation was found in group 1 even on the first postoperative day (+132% +/- 16%). Collagen-induced aggregation was also least compromised in group 1. Epinephrine-induced platelet aggregation did not change and was similar for all groups. Maximum gradient of aggregation was influenced in an identical way as maximum aggregation.(ABSTRACT TRUNCATED AT 250 WORDS)

Blood Platelets↗

PubMed1992

[Cardiorespiratory and microcirculatory effects following volume replacement using a new hydroxyethyl starch preparation].

Volume therapy is often necessary in cardiac surgery to maintain stable haemodynamics. Various different hydroxyethyl starch (HAES) solutions with different concentrations, mean molecular weights, and degrees of substitution are available for this purpose. In determining the ideal type of volume therapy, not only changes in macrohaemodynamics, but also the influence on microcirculatory blood flow have to be taken into account. The efficacy of a new 10% HAES 130/0.5 solution was studied in cardiac surgery patients in comparison to a standard 10% HAES 200/0.5 preparation. METHODS. In patients scheduled for elective aortocoronary bypass grafting who had a pulmonary capillary wedge pressure (PCWP) of less than 4 mm Hg after induction of anaesthesia, either a new 10% HAES 130/0.5 (n = 15) or a standard 10% HAES 200/0.5 solution (n = 15) was infused to double the reduced PCWP; 15 patients without volume therapy served as controls (n = 15). A two-channel laser Doppler skin blood-flux monitor was used to evaluate microcirculatory alterations. Measurements of laser Doppler flux (LDF) was simultaneously performed at the patient's forehead and forearm before and after volume infusion as well as during and after cardiopulmonary bypass (CPB). In addition, changes in gross haemodynamics were documented using a pulmonary artery catheter. Plasma viscosity and various laboratory parameters, including calculation of intrapulmonary right-to-left shunting (Qs/Qt), were also measured. RESULTS. Cardiac index (CI) increased in both volume groups (HAES 130: max. +38%; HAES 200: +55%). The increases in PCWP and CI were maintained at 40 min after volume infusion only in the HAES 200 patients. Systemic vascular resistance (SVR) decreased most markedly after infusion of HAES 200 (-34%; HAES 130: -18%). No further differences in gross haemodynamics could be seen after CPB. Plasma viscosity and colloid osmotic pressure increased in both HAES groups without significant differences. During the entire investigation period, pulmonary gas exchange (paO2) and Qs/Qt did not differ between the groups. Infusion of both HAES solutions resulted in an increase in LDF that was most pronounced after infusion of HAES 200 (forehead LDF: +81%; HAES 130: +18%) and was evident in the post-bypass period only in these patients (LDF: HAES 200: +82%; HAES 130: -20%; control: -43%). No correlation between LDF values and the other haemodynamic and laboratory parameters could be demonstrated. CONCLUSION. The improvement in macrohaemodynamics was of shorter duration after infusion of the new HAES 130 solution than after standard HAES 200. Volume replacement with HAES 200 resulted in an increase in microcirculatory blood flow that was more pronounced and of longer duration than in the HAES 130 patients. Thus, HAES 130 seems to be less effective than HAES 200 for volume replacement; HAES 200 should be preferred in patients undergoing cardiac surgery.

Cardiac Surgical Procedures↗

PubMed1992

Heparin management during cardiac surgery with respect to various blood-conservation techniques.

BACKGROUND: Various methods to reduce blood consumption are used in cardiac surgery. This study was designed to investigate the influence of various blood-conservation techniques on heparin plasma levels and coagulation variables in the perioperative period. METHODS: Anticoagulation was achieved by application of 300 units/kg bovine heparin before cardiopulmonary bypass (CPB). Ninety patients undergoing coronary bypass surgery were randomly divided into six groups according to different blood-conservation methods: group 1, blood during and after CPB was concentrated by a cell saver (CS); group 2, blood was concentrated by means of a hemofiltration device (HF); group 3, acute normovolemic hemodilution (ANH) was performed in combination with the CS technique (ANH-CS); group 4, ANH was carried out in combination with an HF during CPB (ANH-HF); group 5, acute plasmapheresis (APP) was performed and a CS was used during CPB (APP-CS); and group 6, APP was used in combination with an HF device (APP-HF). RESULTS: Heparin plasma concentration during CPB did not differ significantly among the six groups, ranging from 1.60 to 2.03 units/ml. Antagonization with protamine sulfate after termination of bypass in a 1:1 ratio decreased heparin concentration almost to baseline values. Fibrinogen concentration and antithrombin-III level were lowest in the CS group but were not decreased critically during the entire investigation period. Activated clotting time differed widely among the patients (range 383 to 807 seconds) and showed no significant correlation to heparin plasma levels. Partial thromboplastin time was higher than 300 seconds during the entire period of CPB, also indicating sufficient anticoagulation. Blood loss until day 1 after surgery was significantly most pronounced in the CS group and least in the APP-HF group. CONCLUSIONS: The blood conservation techniques used in this study were safe with regard to sufficient anticoagulation during CPB. No insufficient antagonization with protamine could be observed in the postbypass period.

Antithrombin III↗

PubMed1991

RETRACTED: Six different hemofiltration devices for blood conservation in cardiac surgery.

This article has been retracted: please see Elsevier Policy on Article Withdrawal (http://www.elsevier.com/locate/withdrawalpolicy). This article has been retracted at the request of the Editor. Reason: By comparing the results of this article with results reported by Berend Fedderson (Hämofiltration als blutsparendes Verfahren in der Herzchirurgie: sechs verschiedene Hämofilter im Vergleich; Niebüll, Germany; http://d-nb.info/930239350), it has been determined that experimental outcomes have been altered. Thus, the research published in this article was misrepresented to The Annals of Thoracic Surgery and the article should be retracted from the scientific record.

Aged↗

PubMed1991

Cardiorespiratory responses to hypertonic saline solution in cardiac operations.

Infusion of small volumes of hypertonic saline solution (HS) seems to be of benefit in patients with impaired perfusion. The cardiorespiratory response to a 7.2% NaCl solution prepared in hydroxyethylstarch (HES) solution was investigated prospectively in patients undergoing prolonged cardiopulmonary bypass (CPB) (HS-HES group; n = 15); 6% HES 200/0.5 solution was infused in a control group (HES group; n = 15). Volume was given preoperatively to double low pulmonary artery occlusion pressure (less than 4 mm Hg) within 20 minutes. Hemodynamics, oxygen transport variables, and pulmonary gas exchange were studied before and after infusion as well as before and after CPB. Significantly less HS-HES solution (3.06 +/- 0.2 mL/kg) than 6% HES 200/0.5 solution (10.3 +/- 0.9 mL/kg) was necessary to double baseline pulmonary artery occlusion pressure. Fluid balance during CPB was negative in the HS-HES patients (-0.05 mL/kg.min CPB) and was lowest in this group even 5 hours after CPB. Mean arterial pressure, pulmonary arterial pressure, and heart rate were without differences between the groups. Changes in cardiac index (+40%) and total systemic resistance (-25%) were significantly most pronounced in the HS-HES patients, continuing even until the end of operation. Pulmonary gas exchange (arterial oxygen tension, intrapulmonary right-to-left shunting) was least compromised in these patients, particularly after bypass. Oxygen consumption was without difference between the groups; oxygen delivery increased significantly more in the HS-HES patients due to the larger increase in cardiac output.(ABSTRACT TRUNCATED AT 250 WORDS)

Cardiopulmonary Bypass↗

PubMed1991

Does the technique of cardiopulmonary bypass affect lung water content?

Several efforts have been made to improve the technique of cardiopulmonary bypass (CPB), including the use of pulsatile flow and the modification of cannulation technique. The present study focused upon extravascular lung water (EVLW) in 60 aortocoronary bypass patients subjected to four different perfusion techniques during CPB: group 1 (n = 15): non-pulsatile flow and standard cannulation; group 2 (n = 15); pulsatile flow and standard cannulation; group 3 (n = 15): nonpulsatile flow and monoatrial cannulation (i.e., always "partial" bypass during CPB); group 4 (n = 15): pulsatile flow and monoatrial cannulation. EVLW content was measured using the double-indicator dilution technique with indocyanine green; in addition, various hemodynamic and laboratory variables were measured. Lung water content rose above normal values (mean: 5.79 +/- 0.33 ml/kg) only in the groups submitted to the standard cannulation technique, irrespective of whether the perfusion flow was pulsatile or not (group 1: + 27.4%; group 2: + 25.5%). Pulmonary gas exchange, too, was compromised only in these patients (PaO2 in group 1 -19% and in group 2 -17%; Qs/Qt in group 1 + 36 rel. % and in group 2 + 29 rel. %), whereas all patients with monoatrial cannulation and partial bypass throughout the CPB period showed no rise in EVLW content or Qs/Qt and no drop in PaO2. From the results of this study we conclude that pulsatile perfusion during open heart surgical procedure has no advantages in regard to lung water content. Monoatrial cannulation with partial bypass at all times during CPB, however, seems to be beneficial, probably owing to the maintenance of pulmonary circulation during the bypass period.

Aged↗

PubMed1991

RETRACTED: Does the preparation of heparin influence anticoagulation during cardiopulmonary bypass?

Various preparations of heparin from different manufacturers are commercially available. The influence of bovine lung heparin (BLH) and porcine mucosal heparin (PMH) on anticoagulation and heparin plasma concentration was investigated in four groups of 10 patients undergoing elective aortocoronary bypass grafting either after single dose or repetitive dose (after 60 minutes) of one of these heparin preparations. Heparin plasma concentration increased significantly after injection of heparin (BLH: minimum, 1.67 U/mL; maximum, 2.10 U/mL; PMH: minimum, 1.69 U/mL; maximum, 2.15 U/mL). Sixty minutes after the initial dose, heparin plasma levels were higher in the patients who received PMH. Supplemental heparin doses 60 minutes after the loading dose increased plasma heparin concentration only with porcine mucosal heparin. Elimination of heparin in the urine was not different among the groups. Fibrinogen and antithrombin III concentrations, as well as activated clotting time (ACT; always greater than 400 seconds) and partial thromboplastin time (PTT; always greater than 300 seconds), did not differ among the groups, indicating effective anticoagulation during the bypass period with both types of heparin. It can be concluded that sufficient anticoagulation can be achieved with either kind of heparin. PMH seems to be longer acting and a repeat dose in these patients seems to be necessary only if cardiopulmonary bypass lasts longer than 90 minutes.

Aged↗

PubMed1991

[Anesthesia in heart surgery].

Today, the performance of anaesthesia in cardiac surgery is on a high quality level. It requires special knowledge of the various operative techniques, the different methods of extracorporeal circulation and haemodynamic changes of the underlying cardiological disease, as well as extensive experience in cardiac and vasoactive drugs. Heart patients are now being operated on in many departments of cardiac surgery. Over and above this patients with more or less severe cardiac diseases are being looked after in every Department of Anaesthesiology, thus, every anaesthesiologist should acquaint himself with these specific problems during his specialist training.

Adult↗