Biomedical subjects

G Hempelmann

Publications and source records attributed to G Hempelmann.

At least 271 records · Page 15Linked to original sources

PubMed1994

[Lymphocyte subpopulations in controlled hypotension with sodium nitroprusside].

AIM: Induced hypotension is an anaesthesiological method to reduce blood loss in surgical patients. The aim of this study was to investigate whether induced hypotension with sodium nitroprusside (SNP) causes changes in lymphocyte subpopulations. METHODS: In a prospective randomised evaluation 30 patients undergoing elective oto-rhino-laryngological interventions were studied. In 15 patients SNP was administered to reduce the mean arterial pressure to 50 mmHg. There was a control group of another 15 patients. Anaesthesia was induced with etomidate and maintained with isoflurane. At 7 a.m. on the day of operation (T1), 10 minutes after induction of anaesthesia (T2), 60 minutes after T2 (T3, end of SNP-infusion), 120 minutes (T4) after T2; 180 minutes (T5) after T2, and at 7 a.m. on the following morning (T6) blood samples were taken. A new method (whole blood) was used to mark 6 different lymphocyte subpopulations with monoclonal antibodies which were measured by flow cytometry. RESULTS: In both groups a significant decrease in total lymphocyte count (from 32.7 x 10(9) cells/l preoperatively to 13 x 10(9) cells/l the following morning in the SNP-group and from 31 x 10(9) cells/l to 14.2 x 10(9) cells/l the following morning in the control group) was observed. In the SNP-group the HLA-DR positive T-lymphocytes increased from 11.8% at T1 to 19.2% at T5 and 22.3% at T6. No statistically significant changes were found in percentage of T-, T4-, T8-, B-lymphocytes and natural killer cells. CONCLUSION: The increase in the percentage of activated T-lymphocytes is possibly due to an activation of the sympatho-adrenergic system after sodium nitroprusside-infusion and a subsequent redistribution of these cells from other organs (bone marrow, spleen, lymph nodes). The cell-mediated and the humoral immunity are not altered by induced hypotension. In discussing this result, the age of the patients, the extent of the surgical trauma, the anaesthesiological procedure and the methodological aspects in the lymphocyte assay should be taken into consideration.

Adolescent↗

PubMed1994

[A possible risk for geriatric risk patients caused by intraoperative disorder of cerebral energy utilization?].

OBJECTIVE: This study was carried out on cerebrospinal fluid (CSF) to investigate the perioperative course of certain ischaemic markers, namely neurone-specific enolase (NSE), creatine kinase (CK-BB), hypoxanthine, and lactate in order to identify a disturbed cerebral energy utilisation which could be responsible for the development of temporary mental dysfunctions. Those dysfunctions are characterised by preserved memory content and perception, but the coordination and association of these functions are disturbed. Typical clinical signs are motor restlessness, disordered emotions, and symptoms of dementia. Little is known about the aetiology of those symptoms, but they are most likely due to various events, such as direct drug effects, the extent of surgical trauma, sensorial deprivation, and disturbed perfusion. METHODS: Eight orthopaedic patients (ASA III or IV) scheduled for removal of their total hip replacement were anaesthetised by catheter-spinal anaesthesia (CSA) for pain relief in combination with standardised, modified neuroleptanalgesia (NLA). At six defined times (15 hours preoperatively, immediately before and after surgery and 6, 24, and 36 hours postoperatively) CSF samples were drawn and the ischaemic markers were determined by means of radioimmunoassay (NSE), electrophoresis (CK-BB), photometry (lactate), and high-pressure liquid chromatography (hypoxanthine). The release of ischaemic markers into CSF correlates linear with the extent of ischaemic brain damage. RESULTS: Mean concentrations of the following ischaemic markers increased in all patients intraoperatively: NSE from 12.3 ng/ml to 13.4 ng/ml, hypoxanthine from 1.86 mumol/l to 3.73 mumol/l, and lactate from 1.4 mmol/l to 2.0 mmol/l respectively, all of which returned to normal within 36 hours. The CK-BB concentrations were all within normal values and not affected by the operation during this investigation. CONCLUSION: Although no clinical signs of temporary mental dysfunction have been observed, the results indicate that in CSF ischaemic markers temporarily undergo certain changes in their concentrations during the removal of total hip replacements in elderly patients. These changes are reason for assuming that risk patients may suffer a temporary disturbed cerebral energy utilisation intraoperatively, even if stable clinical and cardiovascular conditions prevail under anaesthesia. Such a temporary ischaemic penumbra might be responsible for the postoperative development of temporary mental dysfunctions.

Aged↗

PubMed1994

Influence of different anticoagulation regimens on platelet function during cardiac surgery.

Qualitative platelet defects are of great importance as a cause of bleeding in cardiac surgery. We have studied the effects of different anticoagulation regimens on platelet function in 60 patients undergoing elective aorto-coronary bypass grafting with cardiopulmonary bypass (CPB). Patients were allocated randomly to four groups (each group n = 15) to receive either: bovine heparin 300 u. kg-1 (standard); heparin 300 u. kg-1 followed by a continuous infusion of 10,000 u. kg-1 until the end of CPB; heparin 600 u. kg-1; or heparin 600 u. kg-1 in addition to high-dose aprotinin 2 million iu before CPB, 500,000 iu h-1 until the end of operation and 2 million iu added to the prime. Platelet function was evaluated by aggregometry (turbidometric technique) using adenosine triphosphate (ADP) 2.0 mumol litre-1, collagen 4 microliters ml-1, adrenaline 25 mumol litre-1 and saline solution (control) as inducers. Both maximum aggregation and maximum gradient of aggregation were measured in arterial blood samples before, during and after CPB until the first day after operation. Mean total dose of heparin given in groups 2, 3 and 4 was more than 50,000 u. and differed significantly from that of group 1 (28,150 (SD 4700)u.). Platelet aggregation variables were most depressed during CPB and until the end of surgery in groups 2 and 3 (maximum aggregation - 54% to - 75% of baseline values). In the postoperative period, platelet function recovered but did not completely reach baseline values in these patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗

PubMed1994

Cardiopulmonary actions of intravenously administered enalaprilat in trauma patients.

OBJECTIVE: To determine the cardiopulmonary actions of the intravenous administration of the angiotensin-converting enzyme inhibitor enalaprilat in hypertensive trauma patients. DESIGN: Prospective, before/after trial. SETTING: Intensive care unit (ICU) of a university hospital. PATIENTS: Twenty critically injured and hypertensive ICU patients. All patients were receiving continuous sedation (fentanyl and midazolam) for at least 2 days before the injection of enalaprilat and had a mean arterial pressure (MAP) of > 95 mm Hg. "Responders" were defined as having a decrease in MAP of > 15% within 30 mins after enalaprilat injection. INTERVENTIONS: Intravenous administration of 0.06 mg/kg of the angiotensin-converting enzyme inhibitor enalaprilat. Repeated doses were given when no sufficient response (decrease of MAP of > 15% within 30 mins after injection) was seen ("nonresponders"). MEASUREMENTS: In addition to standard hemodynamic monitoring, right ventricular hemodynamics and oximetric variables were also documented. Measurements were carried out before enalaprilat injection (during hemodynamic steady state [baseline values]) and at 1, 5, 10, 20, 30, 60, and 120 mins after enalaprilat administration. MAIN RESULTS: MAP was successfully controlled in 17 of 20 patients (maximum decrease -27 mm Hg [-26%]). In the three other patients, even reinjection of enalaprilat (0.06 mg/kg) did not sufficiently reduce MAP. In the 17 responders, heart rate did not increase, whereas central venous pressure, pulmonary arterial pressure, and pulmonary artery occlusion pressure decreased significantly after intravenous administration of enalaprilat. Cardiac index changed only slightly (mean maximum +0.70 L/min/m2 [+18%]). Right ventricular ejection fraction increased from 36% to 45% (p < .05); right ventricular end-diastolic and end-systolic volume index decreased significantly. Both systemic and pulmonary vascular resistance indices decreased within the investigation period (-31% and -16%, respectively). Pao2/FIO2, intrapulmonary right-to-left shunting, and oxygen extraction ratio were not altered. Oxygen delivery index (+17%) and oxygen consumption index (+20%) increased during the investigation period (p < .04). CONCLUSIONS: The intravenous administration of enalaprilat successfully decreased blood pressure in most of our patients. Mechanisms other than the renin-angiotensin system also appear to be involved in hypertensive, critically ill patients. Pulmonary function was not altered; right ventricular function, and both oxygen consumption and oxygen delivery improved in the enalaprilat responder group. Thus, the availability of intravenous enalaprilat seems to enlarge our armamentarium for treating hypertension in the critically ill patient.

Acute Disease↗

PubMed1994

Continuous hemofiltration and platelet function in critically ill patients.

OBJECTIVE: To evaluate platelet function in patients undergoing continuous pump-driven veno-venous hemofiltration. DESIGN: Prospective study. SETTING: Surgical intensive care unit of a university hospital. PATIENTS: Twenty consecutive, critically ill patients with acute renal failure (serum creatinine concentration > 3.0 mg/dL (> 265 mumol/L), serum urea > 200 mg/dL (> 33 mmol/L), urine output < 20 mL/hr) secondary to sepsis or trauma. A comparable group (n = 20) without renal failure and not undergoing hemofiltration served as a control group. INTERVENTIONS: Continuous pump-driven veno-venous hemofiltration was used in patients with renal insufficiency. Pump flow ranged from 60 to 100 mL/hr. MEASUREMENTS AND MAIN RESULTS: Platelet function was assessed by a turbidimetric technique using a double-channel aggregometer. Aggregation was induced by adenosine diphosphate (ADP) (2.0 mumol/L), collagen (4 micrograms/mL), epinephrine (25 mumol/L), and saline solution (control). Maximum aggregation was considered to be the maximum increase in light transmission after the addition of the aggregating agents. The maximum gradient of aggregation was considered to be the maximum increase per minute. Measurements were carried out before hemofiltration (baseline values) and during the following 5 days. In the control group, blood samples were taken at corresponding data points. Eight patients undergoing continuous hemofiltration survived during the investigation period; 16 patients in the control group survived. There were no significant differences among the two groups with respect to standard coagulation variables. Maximum platelet aggregation was lower than in normal patients after the addition of all three inductors (ADP, collagen, and epinephrine). In control patients, all aggregation variables remained almost stable during the entire investigation period. In the hemofiltered patients, maximum platelet aggregation was significantly reduced (ADP, decrease of 62 relative % from baseline values; collagen, decrease of 86 relative % from baseline values; epinephrine, decrease of 77 relative % from baseline values). Maximum platelet aggregation was also depressed in these patients (ADP, decrease of 40 relative % from baseline values; collagen, decrease of 88 relative % from baseline values; epinephrine, decrease of 85 relative % from baseline values). When platelet aggregation variables were reduced greater than a decrease of 60 relative % from baseline values (in all induction groups), the mortality rate was 100%. CONCLUSIONS: Continuous pump-driven veno-venous hemofiltration significantly changed platelet aggregability, which became obvious 2 to 3 days after the start of hemofiltration.

Acute Kidney Injury↗

PubMed1994

Changes in regulators of circulation in patients undergoing continuous pump-driven veno-venous hemofiltration.

Continuous pump-driven veno-venous hemofiltration (CVVH) has become an established method for treatment of acute renal failure (ARF). Since severe disturbances of (micro-) circulation are intimately involved in the bad outcome of these patients, the profile of endocrinological regulators of circulation was prospectively and serially measured in patients undergoing pump-driven CVVH (n = 15). 15 patients with similar APACHE II score, but without ARF and without CVVH were also studied. Endothelin-1 (ET-1), atrial natriuretic peptide (ANP), vasopressin, renin, and catecholamine (epinephrine, norepinephrine) plasma levels were measured before start of CVVH (= "baseline") (in the non-CVVH patients: admission to intensive care unit) and during the next 5 days. Various hemodynamic parameters were additionally monitored. MAP, HR, PAP, CI, and right ventricular hemodynamics (RVEF, RVEDV, RVESV) remained almost unchanged in the CVVH patients and were without differences to the non-CVVH group within the entire investigation period. PCWP and RAP were higher in the CVVH patients already at baseline (RAP, 17.8 +/- 4.0 mmHg; PCWP, 22.1 +/- 4.5 mmHg) (p < .02) and remained elevated in the further course of the investigation. Renin plasma level was higher already at baseline in the CVVH patients (907 +/- 184 pg/ml) (p < .05) and further increased during CVVH (to 1453 +/- 186 pg/mL). Vasopressin increased only in the CVVH group (from 3.80 +/- .66 to 11.85 +/- 1.05 pg/mL) (p < .01).(ABSTRACT TRUNCATED AT 250 WORDS)

Acute Kidney Injury↗

PubMed1994

Isolated circulatory response to intravenous administration of the ACE inhibitor enalaprilat.

The isolated vascular effects of intravenous administration of the angiotensin converting enzyme (ACE) inhibitor enalaprilat were investigated. Thirty male patients undergoing cardiopulmonary bypass (CPB) were studied. According to a randomized sequence, 0.04 mg kg-1 enalaprilat (low-dose, n = 10), 0.08 mg kg-1 (high-dose, n = 10) enalaprilat or saline solution as placebo (control group, n = 10) was given as an i.v. bolus during CPB. Changes in mean arterial pressure (MAP) and venous reservoir (RV) of the extracorporeal circulation were studied as indices of arterial resistance and venous capacitance. Mean arterial blood pressure (MAP) and peripheral vascular resistance (SVR) were significantly more reduced in the high-dose enalaprilat group (MAP: -36 mm Hg after 9 min; SVR: -836 dyn s cm-5) than in the low-dose group (MAP: -13 mm Hg after 10 min). Volume of the reservoir (RV) decreased in both enalaprilat treated groups indicating additional (dose-dependent) venous pooling effects of the substance (low-dose: -300 ml; high-dose: -520 ml; control group: -100 ml). Skin capillary blood flow measured by laser Doppler flowmetry (LDF) increased after injection of 0.04 mg kg-1 enalaprilat, whereas it decreased significantly when MAP fell markedly in patients treated with high-dose enalaprilat. I.v. enalaprilat had dose-dependent vasodilating properties in the arterial and venous vessel system indicating reduction in pre- and afterload. Microcirculation in both enalaprilat treated groups improved as long as reduction in blood pressure was not limited.

Blood Pressure↗

PubMed1994

Retracted: Influence of volume replacement with different HES-solutions on microcirculatory blood flow in cardiac surgery.

A variety of hydroxyethyl starch HES preparations with different molecular weight average (Mw) and molar substitution (MS) is available for volume replacement during acute normovolemic haemodilution (ANH). Particularly with regard to microcirculation, the ideal solution for volume therapy has not been found. The influence of four different HES preparations on macro- and microcirculation was investigated in 40 patients scheduled for elective aorto-coronary bypass grafting and undergoing ANH (preoperative withdrawn blood: 10 ml.kg-1): 1) 6% HES with Mw of 450,000 dalton and MS of 0.7; 2) 6% HES with Mw of 200,000 dalton and MS of 0.5; 3) 6% HES with Mw of 200,000 dalton and MS of 0.62; 4) 6% HES with Mw of 40,000 dalton and MS of 0.5. A 5th group without ANH served as a control (10 patients in each group). In addition to systemic haemodynamics and various laboratory parameters, skin capillary blood flow was measured by laser Doppler flowmetry. Laser Doppler flow (LDF) was monitored simultaneously at the patient's forehead and forearm. Changes in systemic haemodynamics were similar in all ANH-patients. Systemic vascular resistance (SVR) was lowest after infusion of HES 200/0.5. The most pronounced increase in plasma viscosity was in patients of group 1 (450/0.7) (P < 0.05) and plasma viscosity remained highest during the entire investigation period in these patients. After ANH, skin capillary blood flow measured at the forehead decreased in all patients except in patients of group 2 (200/0.5: max. +18%). Group 3 (200/0.62) showed the highest decrease in forehead-LDF. During CPB, forehead-LDF decreased significantly in groups 3 (200/0.62) and 4 (40/0.5).(ABSTRACT TRUNCATED AT 250 WORDS)

Blood Circulation↗

PubMed1994

Cold or warm start of cardiopulmonary bypass--influence on microcirculatory blood flow.

In a randomized study of 30 patients undergoing elective aortocoronary bypass grafting, either cold start of cardiopulmonary bypass (CPB) (prime: room temperature [approximately 20 degrees C], n = 15) or normothermic start of CPB (prime: warmed up to the patients' blood temperature, n = 15) were performed. After warm start, CPB was continued using almost normothermia (lowest nasopharyngeal temperature: 35.8 +/- 0.4 degrees C), after cold start hypothermia was used (lowest nasopharyngeal temperature: 28.8 +/- 0.2 degrees C). Changes in microcirculatory perfusion were assessed by measuring skin capillary blood flow at the patient's forearm and forehead using laser Doppler technique. Laser Doppler flow (LDF) was continuously monitored before onset of CPB (= baseline values), 30 seconds, one, five, 10, 15 and 20 minutes after start of CPB. Mean arterial blood pressure (MAP) and systemic vascular resistance (SVR) were reduced by CPB in both groups, with the more pronounced reduction in the normothermic patients. Haemoglobin and plasma viscosity were without differences between the groups. The lowest blood temperature in the hypothermic patients was 21.0 +/- 0.3 degrees C, and the lowest rectal temperature in these patients was 29.0 +/- 0.3 degrees C (20 minutes after start of CPB). Forehead- and forearm-LDF increased significantly in both groups by start of CPB. In the hypothermic patients, this increase was significantly lower, and LDFs were already reduced below baseline values five to 10 minutes after onset of CPB (LDF-forehead -18%, LDF-forearm -72%).(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗

PubMed1994

RETRACTED: Platelet function in critically ill patients.

This article has been retracted: please see Elsevier Policy on Article Withdrawal (https://www.elsevier.com/about/our-business/policies/article-withdrawal). This article has been retracted at the request of the editor In 2018, CHEST published a notice1 that all articles authored by Joachim Boldt be read with caution due to expressions of concern about falsified data. In 2020, CHEST received additional evidence of research misconduct and breaches of scientific integrity that were discovered following an investigation by the author's former institution, the University of Giessen2. In light of this new evidence, this article has been retracted by CHEST. 1. Irwin, R.S., MD, Master FCCP. Notice From the Editor in Chief. CHEST 153(3), p. 767. 2. Mukherjee, J. Statement on the scientific credibility of articles published by Joachim Boldt, formerly professor at Justus Liebig University (JLU), Giessen, Germany. https://ars.els-cdn.com/content/image/1-s2.0-S000709122030163X-mmc3.pdf.

Adult↗

PubMed1994

Influence of aprotinin on the thrombomodulin/protein C system in pediatric cardiac operations.

Thirty consecutive children scheduled for pediatric cardiac operation with cardiopulmonary bypass were included in the study. Before the operation, the patients were randomly divided into two groups: with aprotinin (n = 15, 30,000 U/kg after induction of anesthesia, 30,000 U/kg added to the prime of the cardiopulmonary bypass or without aprotinin (n = 15). Thrombomodulin, (free) protein S, protein C, and thrombin/antithrombin III complex were measured from arterial blood samples taken after induction of anesthesia (at baseline, before aprotinin) and before, during, and after cardiopulmonary bypass until the first postoperative day. Standard coagulation parameters (antithrombin III, fibrinogen, platelet count, and partial thromboplastin time) were without differences between the groups. Thrombomodulin plasma concentrations were within normal range ( < 40 micrograms/L) and were similar in both groups at baseline. During cardiopulmonary bypass and until 5 hours after cardiopulmonary bypass, however, thrombomodulin plasma levels were significantly lower in the children treated with aprotinin. No further differences were observed on the first postoperative day. Protein C and protein S plasma levels did not differ between the two groups. Thrombin/antithrombin III-complex plasma concentrations increased significantly during cardiopulmonary bypass, however, without showing differences between children with (225 +/- 49 micrograms/L) and without (149 +/- 31 micrograms/L) aprotinin treatment. Blood loss and the need for homologous blood and blood products did not differ significantly between the two groups. We concluded that administration of aprotinin resulted in reduced thrombomodulin plasma levels in pediatric patients undergoing cardiac operation without altering protein C/protein S plasma concentration. The exact role of aprotinin in endothelium-derived coagulation should be further studied.

Antithrombin III↗

PubMed1994

[Topographic electroencephalometry following anesthesia induction with ketamine-midazolam].

The neurophysiological action of ketamine has attracted increasing interest in recent years, with special interest in receptor action and in neurophysiological differences between and psychomimetic side effects of the two enantiomorphs. Most of the neurophysiological examinations published deal with ketamine as a single anaesthetic agent, although it has been suggested to that psychomimetic side-effects and haemodynamic deterioration could be avoided by combining ketamine with a sedative drug. The primary aim of our study was to examine the combined ketamine-midazolam action on cerebral activity; secondly, we planned to look at these interactions topographically at different points of the cortex to evaluate topographical differences in the combination's action; thirdly, the cerebral and haemodynamic reactions to anaesthesiological stimuli (intubation, gastric tube) were evaluated and compared. METHODS. Sixteen patients scheduled for elective aortocoronary bypass surgery were examined. Topographical electroencephalometric data were obtained by processed EEG with a CATEEM system at 17 recording points over the cortex and compared with heart rate and arterial blood pressure during the induction period. After documentation of the baseline data ketamine (3 mg/kg) and midazolam (0.15 mg/kg) were applied within 10 min by means of an automatic device. At the end of the infusion period patients were intubated, and after a further 10 min a gastric tube was placed. RESULTS. Induction resulted in increases in delta and beta 2 output (P < 0.05) in the early induction period and in significant decreases (P < 0.05) in alpha 1, alpha 2 and beta 1 activity. No significant change in theta activity was observed throughout the observation period. Intubation led to significant increases of power particularly in the temporal and parietal leads of all frequency bands, but not in the frontal area. Insertion of the gastric tube did not alter cerebral function. CONCLUSION. The interaction of ketamine and midazolam leads to increases in beta 2 and delta power and to significant decreases in the alpha bands and beta 1. Increases of theta activity, a typical effect of single-agent anaesthesia with ketamine, were not observed. Thus, the action of combined ketamine and midazolam on cerebral function is not an additive, but an interactive process. Despite a relatively high induction dosage, haemodynamic changes during intubation occurred and were accompanied by changes in cerebral activity. This can be regarded as incomplete cerebral suppression even by these induction dosages.

Adult↗

PubMed1994

[Structure and organization of ambulatory and day treatment in a university clinic].

Massive increases in costs of health care on one hand and the development of "minimal invasive" surgical techniques on the other hand have enforced an ambulatory or "day-care" treatment policy. Yet, the involvement of hospitals in ambulatory treatment has been limited in Germany, but in the near future this situation will change. In a small number of major hospitals, day surgery programs are going to be established even for infants or for patients at risk for prolonged postoperative monitoring or hospitalization. For these patients the concept of "same day surgery" is suitable. It includes ambulatory anesthesia and operation with the possibility of hospital stay, if necessary. The actual concept at the Justus-Liebig-University Giessen is described. This (at least in Germany) new approach to ambulatory operative treatment decreases costs of health care, improves the chances of hospitals in competition with private practitioners and last not least improves the status of the ambulatory compared with the hospitalized patient.

Adolescent↗

PubMed1994

[Effectiveness of oral versus parenteral iron substitution in autologous blood donors].

OBJECTIVE: Is intravenous iron therapy as efficient as oral iron supplementation in patients undergoing autologous blood donation? DESIGN: Prospective, randomized study. PATIENTS AND SETTING: 30 male and 30 female patients, separated into two groups were examined prior to total hip replacement. INTERVENTIONS: Patients of group O were given 6 x 50 mg Fe2+ aspartate/day orally, and patients of group P were given 0.75 mg/kg BW complex-bound Fe3+ once a week by infusion. In both groups therapy was started two weeks prior to the first donation. The substitution was continued the following six weeks until surgery. Hemoglobin, ferritin plasma concentrations and reticulocytes were monitored. The appearance of unwanted side effects was studied by questionnaire. RESULTS: Hb decreased significantly in both groups. A difference was seen in the reticulocyte count and in the ferritin levels. Here we found a significant increase in group P compared with group O. 40% of the patients who took the iron orally complained about unwanted side effects such as obstipation and diarrhoea, whereas none of the patients of the parenteral group had any complaints. CONCLUSIONS: Stimulation of the erythropoiesis appeared to be more efficient with intravenous iron therapy than with oral iron supplementation. The oral dose has in about 40% unwanted side effects. For this reason a parenteral iron therapy can be considered, but one must be aware that in some cases dangerous anaphylactic reactions could appear.

Administration, Oral↗

PubMed1994

[Intracranial hemorrhage and hemostasis. Monitoring patients after intracranial hemorrhage by determination and follow-up of activation products of blood coagulation].

OBJECTIVE: The aim of the study was to improve the detection of small hemorrhages with minimal symptoms and of unruptured aneurysms after a subdural and subarachnoid bleeding by the control of the intravascular hemostatic system. DESIGN: Prospective, open study. SETTING: Neurosurgical intensive care unit of a university hospital. PATIENTS: 44 patients undergoing a cranial trepanation. Patients of group 1 (control n = 11) had an intrasellar hypophysoma, patients of group 2 (n = 12) a chronic subdural hematoma without a previous traumatic incident and patients of group 3 (n = 15) a subarachnoid hemorrhage caused by an intracranial aneurysm. INTERVENTIONS: After cranial trepanation changes of plasmatic hemostasis have been assessed by means of immunologically determined parameters of coagulation. The investigation included blood parameters (hemoglobin, hematocrit, thrombocytes), clotting status (prothrombin time, partial thromboplastin time, thrombin time, fibrinogen, plasminogen, antithrombin III [AT III] activity and proteinase inhibitors), as well as immunological methods such as fibrinopeptide A (FPA), thrombin-antithrombin III (TAT), protein C and factor XIII activity (F XIII activity). RESULTS: In comparison to group 1 (control) a significant difference (p < 0.001) was seen in groups 2 and 3 for thrombin-antithrombin III (TAT), fibrinopeptide A (FPA), protein C, and the antithrombin III activity. Intra- and postoperatively increased TAT levels in groups 2 (16.9 ng/ml) and 3 (21.1 ng/ml) and decreased protein C levels (group 2: 61% and group 3: 58%) demonstrated an intravascular thrombin generation. On account of the elevated FPA levels in groups 2 (6.5 ng/ml) and 3 (5.7 ng/ml) and decreased AT III activity in groups 2 (58%) and 3 (62%), this thrombin generation was only incompletely compensated. Caused by proteolytic thrombin effects, another sign for a thrombin-induced turnover of clotting factors is the significant reduction (p < 0.001) of F XIII activity in groups 2 (40%) and 3 (44%). In comparison to group 1 this significantly reduced F XIII activity in groups 2 and 3 was correlated (r = 0.99) to changes in FPA and TAT plasma levels, an indication of latent chronic clotting activity. No significant difference was found concerning total amount of infusion, intra- and postoperative blood loss and blood parameters. Eight patients (group 2: 5 patients, group 3: 3 patients) showed a rebleeding episode without operative interventions. In these patients increased clotting activity (TAT, FPA, protein C) caused by proteolytic thrombin effects was combined with a factor XIII activity smaller than 40%. CONCLUSION: The results of the recent study indicated that immunologically determined TAT, FPA, protein C, factor XIII and AT III activities might serve to improve management in patients with intracranial bleeding events. In view of these parameters the evaluation of risks for a rebleeding is improved. A decrease of the plasma factor XIII activity under 40% associated with a latent clotting activity induced by a thrombin generation caused a higher risk of rebleeding after an initial intracranial bleeding event. The necessity of substituting factor XIII in such cases should be elucidated to minimize risks of rebleeding.

Aneurysm, Ruptured↗

PubMed1994

Is continuous cardiac output measurement using thermodilution reliable in the critically ill patient?

OBJECTIVE: Evaluation of continuous cardiac output monitoring based on the thermodilution technique in the critically ill. DESIGN: Prospective clinical investigation. SETTING: A surgical intensive care unit of a university hospital. PATIENTS: Thirty-five critically ill patients (trauma and/or sepsis patients), who needed pulmonary artery catheterization. The patients were prospectively studied according to the following groups: a) patients with a heart rate of > 120 beats/min; b) those patients with a cardiac output of > 10 L/min; c) patients with a cardiac output of < 4.5 L/min; d) patients with a rectal temperature of > 39.0 degrees C; and e) patients with a pulmonary artery catheter inserted for > 4 days. INTERVENTIONS: Therapies were carried out according to modern intensive care medicine protocols by physicians who were not involved in the study. MEASUREMENTS: Cardiac output was monitored continuously using a new, modified pulmonary artery catheter. This catheter has a heating filament by which energy is transmitted to the circulating blood (modified thermodilution technique). A bedside microprocessor calculated cardiac output using a new algorithm. Standard bolus thermodilution technique (10 mL of ice-cold saline solution) was used to compare the continuous cardiac output measurement with the intermittent bolus cardiac output measurement. MAIN RESULTS: A total of 404 pairs of intermittent (bolus) cardiac output and continuous cardiac output measurements were obtained from the 35 patients. The bias (mean difference between bolus cardiac output measurement and continuous cardiac output measurement) of all measurements was 0.03 +/- 0.52 L/min and the 95% confidence limit (mean difference +/- 2 SD) was -1.01/1.06 L/min. Also, continuous cardiac output measurement agreed closely with bolus cardiac output measurement (bias was 0.16 +/- 0.57 L/min in the cardiac output of > 10 L/min group; bias was -0.17 +/- 0.50 L/min for the cardiac output of < 4.5 L/min group). Increased temperature and prolonged length of stay did not influence the agreement of continuous cardiac output measurement with bolus cardiac output measurement (bias was 0.09 +/- 0.51 L/min in the > 39 degrees C rectal temperature group). CONCLUSIONS: Continuous monitoring of cardiac output using a modified pulmonary artery catheter with a heated filament has proven to be accurate and precise in the critically ill patient when compared with the "standard" intermittent bolus thermodilution technique. The continuous monitoring technique enhances our armamentarium for more intensive monitoring of these patients under a variety of circumstances.

Adult↗

PubMed1994

[Value of phosphodiesterase inhibitors in anesthesia and intensive care].

During anesthesia and in intensive care, pharmacological support is often required in patients with preexisting myocardial dysfunction as well as in patients with normal preoperative ventricular function. Abnormalities in both systolic and diastolic function may occur in this situation. Standard therapy used in this situation act on alpha-, beta- or dopaminergic-receptors. However, the observation of beta-receptor down-regulation phenomenon has led to the development of substances which act independently of the beta-receptor. The imidazole derivative enoximone belongs to a new class of non-catecholaminergic positive inotropics, which acts by selectively inhibiting phosphodiesterase type-III thus using a mechanism distal of the beta-receptor. Enoximone has been proven to successfully improve hemodynamics by either its positive inotropic and lusitropic or its vasodilating properties. The expected increase in MVO2 secondary to the increase in myocardial contractility appears to be compensated by the decrease in ventricular pre- and afterload. The most obvious positive hemodynamic effects are reported for patients undergoing cardiac surgery. In both adults and pediatric patients hemodynamics were improved significantly in this situation. There is a particular indication for enoximone for patients with severely impaired hemodynamics awaiting heart transplantation ("pharmacological" bridging). The first promising results were documented when PDE-III-inhibitors were given in myocardial infarction and septic shock patients. The most important risk associated with the use of enoximone is the reduction in blood pressure due to its arterial and venous vasodilatory effects. Limitation to a bolus of 0.5 mg/kg or a perfusor controlled therapy help to avoid critical decrease in perfusion pressure.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1993

Does platelet size correlate with function in patients undergoing cardiac surgery?

OBJECTIVE: Platelet dysfunction secondary to cardiopulmonary bypass (CPB) is one of the major reasons for nonsurgical post-operative bleeding in cardiac surgery. Whether platelet size is an indicator for platelet function was investigated in patients undergoing coronary artery bypass grafting. DESIGN: Prospective study. SETTING: Intra-operative, cardiac surgery operations. PATIENTS: 80 consecutive patients undergoing coronary artery bypass grafting. Excluding criteria were pre-operative coagulation disorders and medication with anticoagulants within the last 10 days before the operation day. MEASUREMENTS AND RESULTS: Platelet function was assessed by aggregometry using a turbidimetric method (inductors: ADP 2.0 mumol/l, collagen 4 micrograms/l, epinephrine 25 mumol/l). Mean platelet volume (MPV) was measured by an electrical conductivity method. Measurements were carried out before, during, and after CPB until the 1st post-operative day on intensive care unit (ICU). Platelet size decreased significantly during CPB (max. -25% after weaning from bypass) and returned to baseline values on the 1st post-operative day. Platelet count (ranging from 93 - 304 x 10(9)/l) did not correlate significantly with MPV or aggregation variables. Maximum aggregation and maximum gradient of aggregation induced by ADP and collagen were significantly decreased by CPB with the most pronounced reduction at the end of CPB (ranging from -25% to -45%). Analyses of co-variance revealed a significant correlation between changes in MPV and changes in aggregation variables (ADP, collagen). CONCLUSIONS: Platelet volume is easy to measure even in the operation room or in ICU and may indicate abnormalities in platelet function in the post-bypass period of cardiac surgery patients.

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