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Biomedical subjects

G Hempelmann

Publications and source records attributed to G Hempelmann.

At least 199 records · Page 11Linked to original sources
PubMed1996

[NO inhalation in heart surgery procedures: relevance for right heart function?].

UNLABELLED: The right ventricle is more jeopardized by a cardiopulmonary bypass than the left one. Impaired right ventricular performance may profit from an afterload reduction. A selective reduction in pulmonary artery pressure (PAP) or pulmonary vascular resistance (PVR) without impairment of the systemic circulation seems to be possible by inhalation of nitric oxide (NO). Therefore in the present study we looked for influences of NO inhalation on PAP, PVR and right heart parameters immediately after weaning from the bypass. The dependence of endothelial function on age, preoperative heart function and extracorporeal circulation is well established. The relevance of such parameters on NO inhalation was also investigated. METHODS: After ethical approval and informed consent were obtained, 20 patients with moderately increased PAP were included in the study. Ten patients inhaled NO at a concentration of 30 ppm; the other group served as a control group. Measurement points were 10 min after the end of extracorporeal circulation (baseline), 3, 10, and 20 min after the start, as well as 10 min after the end of NO inhalation. NO was injected near the tube into the tubing system during inspiration; dosage and monitoring of the concentration were achieved by means of a chemiluminometer. Measured parameters consisted of PAP, PVR, right ventricular ejection fraction and volumes, systemic blood pressure and resistance, central venous pressure, pulmonary capillary wedge pressure, and oxygenation parameters (paO2, pvO2, paCO2). RESULTS: The decrease in PAP (from 29.7 +/- 3.9 to a minimal 25.4 +/- 4.3 mm Hg, P < 0.005) and in PVR (from 169.4 +/- 51.9 to a minimal 116.3 +/- 60.9 dyn.s.cm-5, P.0.05) did not improve right heart function. A similar significant increase in SVR was observed in the NO group and in the control group. Age, haemodynamic parameters or duration of the ischaemic phase of the cardiopulmonary bypass did not influence the course of PAP or PVR. Changes in PAP (from 30.0 +/- 4.0 to a minimal 26.7 +/- 3.6 mm Hg, P < 0.05) and PVR (from 149.0 +/- 41.5 to a minimal 125.2 +/- 51.5 dyn.s.cm-5, in the control group were not statistically different from those in the NO group. Indicators of intoxication like an increase in NO2 or methaemoglobin concentrations or changes in compliance or resistance were not observed. CONCLUSIONS: Patients with moderate pulmonary hypertension did not profit from NO inhalation immediately after weaning from the cardiopulmonary bypass. The decreases in PAP and PVR found in the NO or control group did not improve right-heart function. When the NO and control group were compared, specific effects of NO inhalation on PAP and PVR must be questioned. This could perhaps be explained by data from animal experiments, which found high endogenous NO levels in situations with elevated cytokine levels. Cytokines are increased after extracorporeal circulation. Oxygenation was not impaired by inhalation of relatively high concentrations of NO. For all investigations with NO inhalation not preceded by steady-state conditions, a control group is recommended.

Aged↗
PubMed1996

[The in vitro effect of alpha-2 agonists on thrombocyte function and density of thrombocyte alpha-2 receptors].

UNLABELLED: alpha 2-Agonists are being used increasingly in anaesthesia and intensive care medicine because of their antihypertensive, analgesic and sedative properties. Platelets bear alpha 2-receptors on the cell surface. Stimulation of these receptors by agonists induces platelet aggregation. The present study examined whether in vitro incubation of blood with the alpha 2-agonists clonidine and dexmedetomidine decreases alpha 2-receptor density and hereby influences platelet aggregation. METHODS: Whole blood of 20 healthy volunteers was incubated over 24 h at 37 degrees C with 1 ng/ml clonidine or 1 or 10 ng/ml dexmedetomidine. Induced platelet aggregation was determined by means of turbidometry. Epinephrine (22 mumol/l) or collagen (20 mg/l) served as inductors. The density of alpha 2-receptors was measured in radioligand assays with 3H-Yohimbine. Phentolamine was used to assess unspecific binding. The data were analyzed with an analysis of variance. RESULTS: Neither 1 ng/ml clonidine nor 1 ng/ml dexmedetomidine altered platelet aggregation or alpha 2-receptor density in comparison with the control sample. As a major result we found that 10 ng/ml dexmedetomidine caused a significant (P < 0.05) reduction in epinephrine-induced platelet aggregation (16.0 +/- 5.4%, n = 20, mean +/- SEM) compared with the control (46.0 +/- 1.3%, n = 20). alpha 2-Receptor density was not any different from the control. CONCLUSIONS: This in vitro study showed that clinically relevant concentrations of 1 ng/ml clonidine or dexmedetomidine did not alter platelet aggregation or alpha 2-receptor density, even after 24 h exposure. However, 10 ng/ml dexmedetomidine was found to diminish significantly epinephrine-induced platelet aggregation, but did not change alpha 2-receptor density. This result showed that desensitization of platelet aggregation can occur without quantitative changes in alpha 2-receptors.

Adrenergic alpha-2 Receptor Agonists↗
PubMed1996

[Cost aspects in anesthesia. Propofol versus isoflurane anesthesia].

UNLABELLED: Cost control is no longer an option, but a necessity. Propofol anaesthesia is expensive, however, the true differences in comparison to volatile anaesthetics (isoflurane) are not known. METHODS: Sixty patients undergoing either thyroidectomy (n = 30) or laparoscopic cholecystectomy (n = 30) were randomly divided into 3 groups of 20 patients. In group I propofol and fentanyl were used for anaesthesia, in group II isoflurane ('standard' isoflurane anaesthesia), and in group III isoflurane using a low-flow system (fresh gas flow 2 l/min) was given. All patients were ventilated using 70% N2O in oxygen. Vecuronium was used in all cases for muscle relaxation. Isoflurane consumption was measured by weighing the isoflurane vaporizer. RESULTS: Biometric data and time of administration of the anaesthetic were similar in the three groups. Propofol patients stayed significantly shorter than isoflurane patients in the postanaesthesia care unit (PACU). Costs of additional drugs (antiemetics, analgesics) in the PACU were least in the propofol patients. Costs were without differences between the propofol (78.30 DM/patient) and 'standard' isoflurane groups (81.69 DM/patient). Patients in group III showed the lowest overall costs (57.46 DM/patient) (P < 0.05). CONCLUSION: A climate of cost-consciousness and cost-containment prevails at the present time. The costs of propofol and 'standard' isoflurane anaesthesia were without differences; however, isoflurane used in a low-flow system had the lowest cost in this study. Doubts are justified, however, as to whether the choice of anaesthetic agents may considerably lower the costs of an anaesthesia department.

Adult↗
PubMed1996

[Is the elimination of osteosarcoma cells with intraoperative "mesh autotransfusion" and leukocyte depletion filters possible?].

UNLABELLED: Intraoperative autotransfusion is contraindicated in cancer surgery because of the possible risk of systemic tumor spread. The aim of the present study was to investigate whether a cell saver in combination with a white blood cell depletion filter can remove osteosarcoma cells. METHODS: A defined number of osteosarcoma cells from an established cell line were added to red cell concentrates and Ringer solution. The tumor cell concentration was 1000/ ml in the first five experiments, 7111/ml in test no. 6, 1667/ml in test no. 7 and 167/ml in test no. 8. Following thorough mixing, each unit was processed separately by a cell saver (DIDECO BT 795/P) in its normal operation mode to produce a red cell concentrate. This red cell concentrate was filtered using a leukocyte depletion filter (PALL BPF 4). Samples were taken before and after processing with the autotransfuser and after filtration with the white cell depletion filter. Cytospin specimens from all samples were examined for osteosarcoma cells by three different methods (Papanicolaou stain, Vimentin antibodies, DNA analysis). RESULTS: After processing with the autotransfuser, tumor cells were identified in the red cell concentrate. No osteosarcoma cells were evident after the combined use of cell saver and leukocyte depletion filter. CONCLUSION: The sole use of the autotransfuser DIDECO BT 795/P during osteosarcoma surgery is not recommended because of the potential danger of retransfusion of malignant cells. In combination with the leukocyte depletion filter PALL BPF 4, no osteosarcoma cells were identified in the red cell concentrate. Since the adhesiveness of tumor cells from established cell lines may be different from that of tumor cells in the intraoperative salvaged blood, further studies with blood from the surgical field are necessary to determine the efficacy of white cell depletion filters to eliminate osteosarcoma cells.

Blood Transfusion, Autologous↗
PubMed1996

Normothermic versus hypothermic cardiopulmonary bypass: do changes in coagulation differ?

BACKGROUND: The differences between hypothermic and normothermic cardiopulmonary bypass (CPB) on platelet function and endothelial-related coagulation (eg, the thrombomodulin/protein C/protein S system) should be investigated. METHODS: According to a randomized sequence, 30 patients undergoing aortocoronary bypass grafting underwent either hypothermic (rectal temperature, 27 degrees C to 28 degrees C, n = 15) or normothermic CPB (rectal temperature, more than 35 degrees C, n = 15). Arterial blood samples were taken after induction of anesthesia (baseline values), before, during, and immediately after CPB, 5 hours after CPB, and on the morning of the first postoperative day. Circulating thrombomodulin, (free) protein S, protein C, and thrombin/antithrombin III complex were measured from these samples. Platelet function was assessed by aggregometry (turbidometric technique) induced by adenosine diphosphate (2 mumol/L), collagen (4 micrograms/L), and epinephrine (25 mumol/L). RESULTS: Hypothermic patients showed a significantly higher blood loss and need for homologous blood than the normothermic patients. Thrombomodulin plasma level increased more in the hypothermic (from 28 +/- 5 ng/mL to 60 +/- 10 ng/mL) than in the normothermic group (from 28 +/- 7 ng/mL to 41 ng/mL); p < 0.05). Both protein C and (free) protein S were reduced significantly in the hypothermic (protein C, from 88% +/- 25% to 60% +/- 11%; protein S, from 71% +/- 10% to 40% +/- 8%) than in the normothermic patients. Platelet aggregation was significantly more decreased in the hypothermic (adenosine diphosphate, maximum decrease by -43% relative to baseline) than in the normothermic patients (adenosine diphosphate, maximum decrease by -22% relative to baseline). In the hypothermic CPB group, platelet aggregation had recovered incompletely, whereas in the normothermic patients platelet aggregation even slightly exceeded baseline values. CONCLUSIONS: Hypothermic CPB resulted in more pronounced alterations of platelet aggregation and endothelial-related coagulation than normothermic CPB. Plasma levels of soluble thrombomodulin were more increased in hypothermic than in normothermic CPB indicating more extensive endothelial damage or activation associated with hypothermic CPB.

Aged↗
PubMed1996

Perioperative microbiologic monitoring of tracheal aspirates as a predictor of pulmonary complications after cardiac operations.

The value of preoperative and early postoperative microbiologic testing of tracheal aspirates as a prognostic indicator of the development of pneumonia was evaluated in a prospective study of 213 cardiac surgical patients. Tracheal aspirates were obtained immediately after intubation and after the patient's arrival at the intensive care unit. Diagnosis of pneumonia was accepted if at least three of the following criteria were fulfilled: leukocytosis > 15,000 cells/mm3, body temperature >38.5 degrees C, positive results of auscultation, positive results of radiography (new infiltrates that seemed to be consistent with pneumonia), and increased core-reactive protein for more than 2 days after operation. Potentially pathogenic microorganisms were found in 54 (25.4%) of the preoperative tracheal aspirates and in 27 (12.7%) of the early postoperative tracheal aspirates. Positive microbiologic findings correlated with pneumonia in the postoperative course in 24.1% (p < 0.001) if the preoperative culture results were positive, in 48.2% (p < 0.001) if the postoperative culture results were positive, and in 44.0% (p < 0.001) if both were positive. The risk of pneumonia was increased in male patients (p < 0.05) and in patients with chronic obstructive pulmonary disease (p < 0.05). Demographic variables, smoking, acute pulmonary symptoms, temperature, leukocyte count at the day of the operation, and data on the operation and the extracorporeal circulation were not significantly related to pneumonia in the early postoperative course. The risk of development of postoperative pneumonia is significantly higher among patients with colonization of the lower respiratory tract. Positive culture results in routine microbiologic monitoring of tracheal aspirates are predictive of pulmonary complications after cardiac operations.

Adult↗
PubMed1996

Value of body plethysmography in preoperative assessment of thoracotomy candidates.

The usefulness of body plethysmography in the assessment of thoracotomy candidates is not well documented. Reported thresholds for operability are generally expressed in absolute values, which do not take into account a patient's size, age or gender. Spirometric and plethysmographic data of 103 patients undergoing thoracotomy were examined for their ability to predict death due to cardiopulmonary insufficiency, pneumonia, and atelectasis during the first 30 postoperative days. Neither plethysmographic nor spirometric parameters could predict atelectasis. Patients who underwent lobectomy were susceptible to the development of atelectasis. A weak correlation between elevated functional residual capacity (FRC) and occurrence of postoperative pneumonia was found. Lung function testing was not able to separate survivors from non-survivors. Patients with pneumonia were at high risk of death in their postoperative course. Because of the non-linear relationship, a correlation coefficient between spirometric and plethysmographic variables was not calculated. The prevalence of cardiac risk factors was high, so the decision for invasive hemodynamic studies should rather be based upon a patient's history than restricted to patients with impaired lung function. Because of methodological differences, and probably insuitable reference values, body plethysmography cannot substitute for spirometry. For FRC and FRC to total lung capacity (FRC/ TLC) ratio, further investigations must be undertaken to establish a correct reference value.

Adult↗
PubMed1996

Endothelin plasma levels during heart surgery: influence on pulmonary artery pressure?

OBJECTIVE: Some studies found endothelin-1 to be a trigger for pulmonary hypertension. Endothelin-1 is an endothelial derived substance with generally vasoconstrictive properties, but probably vasodilatory effects on pulmonary arteries. The aim of the present study was to look for influences of endothelin-1 plasma values on pulmonary artery pressure. METHODS: Endothelin-1 levels during and after cardiac surgery and correlations to pulmonary artery pressure were tested in 10 control patients and 21 patients with pulmonary hypertension (mean pulmonary arterial pressure > 20 mmHg, systolic pulmonary arterial pressure > 30 mmHg). RESULTS: According to endothelin-1 values before anaesthesia (normal value below 4 pg/ml) patients with pulmonary hypertension could be divided into a "high endothelin-1" (10 patients, mean 8.25 +/- 2.06 pg/ml) and a "normal endothelin-1" (11 patients, mean 2.13 +/- 0.86 pg/ml) subgroup (p < 0.01). Values of the "high endothelin-1" group decreased until end of operation (from 7.58 +/- 2.35 to 2.95 +/- 1.44 pg/ml, n = 6) when pulmonary artery pressure returned to normal. Otherwise they slightly increased (from 9.43 +/- 2.24 to 11.07 +/- 1.96 pg/ml, n = 4). Levels of the "normal endothelin-1" group increased (to 2.55 pg/ml). Endothelin-1 values peaked on the intensive care unit (ICU) in all patients. Baseline endothelin-1 and systolic pulmonary artery pressure values correlated well with each other (r = 0.73, p < 0.001). Endothelin-1 decreased after extracorporeal circulation in all patients in whom pulmonary artery pressure tended to normalise, whereas no rise in pulmonary artery pressure paralleled the marked increase in endothelin-1 on the ICU. Vasodilatory effects of endothelin on pulmonary arteries can attribute to this course. CONCLUSIONS: Endothelin-1 seems not to trigger pulmonary hypertension but rather to vasodilate pulmonary vasculature.

Aged↗
PubMed1996

RETRACTED: Cardiorespiratory changes in patients undergoing pulmonary resection using different anesthetic management techniques.

OBJECTIVE: Pulmonary resection may be associated with considerable alterations of the cardiorespiratory system. The ideal anesthetic regimen for these patients is not yet definitely determined. DESIGN: Prospective, randomized study. SETTING: Single-institutional, clinical investigation in a thoracic anesthesia department of a university hospital. PARTICIPANTS: Fifty consecutive patients scheduled for elective thoracic surgery for lung cancer. INTERVENTIONS: In 20 patients undergoing lobectomy, fentanyl/propofol/nitrous oxide/vecuronium anesthesia was used, and extubation was planned immediately after surgery (group 1A, early extubation). Another 20 patients with lobectomy were anesthetized during fentanyl/midazolam/vecuronium, and they were extubated in the intensive care unit (ICU) (group 1B, late extubation). Ten patients underwent pneumonectomy (extubation planned in the ICU) (group 2, pneumonectomy). Patients of groups 1A and 1B were selected according to a randomized sequence. MEASUREMENTS AND MAIN RESULTS: Extensive hemodynamic monitoring was performed using a pulmonary artery catheter by which right ventricular hemodynamics (right ventricular ejection fraction [RVEF], right ventricular end-systolic, and end-diastolic volumes) were additionally measured. Measurements were performed after induction of anesthesia (supine position, baseline values), before surgery (lateral position), 30 minutes after one-lung ventilation (OLV) was induced, at the end of surgery (supine position), 2 hours after surgery (in ICU), and on the morning of the first postoperative day. Pneumonectomy resulted in an increase in the pulmonary wedge pressure (from 12.2 +/- 2.9 to 18.3 +/- 3.8 mmHg) and a deterioration in right ventricular hemodynamics with a decrease in RVEF from 40.6 +/- 3.4% to 28.8 +/- 4.3% at the end of surgery. These changes were also seen on the morning of the first postoperative day. PaO2/FI02, Qs/Qt, VO2I, and DO2I were also significantly different between pneumonectomy and lobectomy patients. Intraoperatively, patients of group 1A and 1B showed almost similar cardiorespiratory data. During OLV, PaO2/FIO2 was significantly less reduced in group 1A (to 292 +/- 98 mmHg) than in group 1B (to 200 +/- 120 mmHg). Postoperatively, patients of group 1A were orientated, and physiotherapy could be started early. No relevant differences with regard to cardiorespiratory parameters were observed between group 1A and group 1B in the postoperative period until the first postoperative day. CONCLUSIONS: In comparison with lobectomy patients, pneumonectomy resulted in more pronounced and sustained deterioration in right ventricular hemodynamics. The kind of anesthesia regimen did not influence most of the cardiorespiratory parameters intraoperatively, except for Qs/Qt, which was least compromised in the propofol patients during OLV. Early extubation could safely be performed in the lobectomy patients anesthetized with propofol without showing any negative cardiorespiratory effects.

Adult↗
PubMed1996

RETRACTED: Hypothermic versus normothermic cardiopulmonary bypass: influence on circulating adhesion molecules.

OBJECTIVE: Cardiopulmonary bypass (CPB) may result in a whole-body inflammatory response with the risk of subsequent development of organ failure. Leukocyte-endothelial binding followed by neutrophil migration appear to play a central role. This process is markedly influenced by adhesion molecules. Whether plasma levels of circulating adhesion molecules are beneficially influenced by hypothermic CPB was studied in patients undergoing either hypothermic or normothermic CPB. DESIGN: Prospective, randomized study. SETTING: Single-Institutional, clinical investigation in a cardiac anesthesia department of a university hospital. PARTICIPANTS: 30 patients scheduled for elective aortocoronary artery bypass grafting. INTERVENTIONS: The patients were prospectively and randomly divided into two groups: group 1 underwent hypothermic CPB (rectal temperature 27 to 28 degrees C; n = 15) and group 2 normothermic CPB (rectal temperature > 36 degrees C; n = 15). MEASUREMENTS AND MAIN RESULTS: Plasma levels of circulating (soluble) adhesion molecules (endothelial leukocyte adhesion molecules [sELAM-1], vascular cell adhesion molecule-1 [sVCAM-1], intercellular adhesion molecule-1 [sICAM-1], and granule membrane protein 140 [sGMP-140]) were measured from arterial blood samples using enzyme-linked immunosorbent assays (ELISA) after induction of anesthesia (= baseline values), after weaning from bypass, at the end of surgery, 5 hours after the end of CPB, and on the morning of the first postoperative day. Mean rectal temperature of group 1 was 27.2 +/- 0.4 degrees C and 36.7 +/- 0.4 degrees C in group 2. In both groups, plasma levels of sELAM-1 were significantly higher than baseline only 5 hours after CPB. sICAM-1 increased until the first postoperative day (group 1: +35%; group 2: +37%) without, however, exceeding the normal range. sVCAM-1 plasma levels increased after CPB (group 1: +56%; group 2: +40%). At the end of surgery and 5 hours after CPB, sGMP-140 plasma levels were significantly higher in the hypothermic (increase from 301 +/- 34 to 582 +/- 57 ng/mL) than in the normothermic patients (increase from 310 +/- 45 to 480 +/- 32 ng/mL). On the first postoperative day, both groups showed similar, significantly elevated plasma levels of sGMP-140. CONCLUSIONS: Plasma levels of circulating adhesion molecules sELAM-1, sICAM-1, and sVCAM-1 did not differ between hypothermic and normothermic CPB, indicating no differences in endothelial activation between the two groups. Only sGMP-140 plasma levels were increased more after hypothermic CPB. Additional influences of hypothermia on the coagulation system might have contributed to the higher sGMP-140 plasma levels of these patients. The definite role of circulating adhesion molecules in cardiac surgery patients remains to be elucidated.

Aged↗
PubMed1996

Volume replacement with gelatin or hydroxyethylstarch solutions does not impair somatosensory evoked potential monitoring: a haemodilution study in conscious volunteers.

The influence of haemodilution with colloids on somatosensory evoked potentials in non-premedicated volunteers is reported. In seven volunteers (randomized crossover design), blood (20 mL kg-1 within 30 min) was removed and simultaneously replaced by gelatin 3% or hydroxyethylstarch 6%. After 30 min, blood was retransfused within 30 min. Median and posterior tibial nerve somatosensory evoked potentials were recorded from the cortex, second cervical vertebra, Erb's point and 1st lumbar vertebra, respectively. One volunteer experienced a severe allergic reaction to gelatin, therefore only six gelatin trials were evaluated. Haemodilution decreased the haematocrit from 39.8 +/- 1.6% (mean +/- SD) to 31.1 +/- 2.0% (gelatin) and from 40.7 +/- 1.7% to 29.8 +/- 1.5 % (hydroxyethylstarch), respectively. Retransfusion increased haematocrit to 34.4 +/- 0.9% (gelatin) and to 34.2 +/- 1.3% (hydroxyethylstarch). Neither haemodilution with gelatin nor haemodilution with hydroxyethylstarch or retransfusion influenced evoked potentials. In conclusion, the treatment of blood loss up to 30% of estimated blood volume with gelatin or hydroxyethylstarch will not affect somatosensory evoked potential monitoring provided normovolaemic conditions are maintained.

Adult↗
PubMed1996

Comparative use of muscle relaxants and their reversal in three European countries: a survey in France, Germany and Great Britain.

A survey was conducted among British, French and German anaesthetists to evaluate possible national differences in the peri-operative use of muscle relaxants and their reversal agents. The same non-depolarizing relaxants are used in all three countries, with the exception of d-tubocurarine, which is only available in Great Britain, and alcuronium which is mainly used in Germany. The French anaesthetists seem to use significantly less succinylcholine than their peers in Great Britain or Germany for both elective and emergency intubation. Monitoring of neuromuscular blockade still relies mainly on "clinical judgement'. Reversal of non-depolarizing muscle relaxants is performed routinely in Great Britain, while a substantial number of French anaesthetists avoid the use of a reversal. Dose regimes for neostigmine vary largely, with German anaesthetists administering the lowest, and British anaesthetists administering the highest doses. Side effects of reversal agents are reported by colleagues from all three countries in too high a percentage to justify uncritical administration of these drugs. In Germany there seems to be a noteworthy lack of recovery facilities.

Alcuronium↗
PubMed1996

[Adrenergic beta receptors in anesthesia and intensive care medicine].

beta-Adrenoceptors (beta-AR) are divided into a beta 1-, a beta 1-, and a recently cloned beta 3-subtype. beta-AR belong to the group of 7-transmembrane spanners which are coupled via GS-proteins to the enzyme adenylyl cyclase. Instead of being static entities, beta-AR undergo dynamic regulation upon repeated or prolonged exposure to agonists (down-regulation) or antagonists (up-regulation). After exposure to agonists, an early desensitisation caused by phosphorylation of amino acid residues can be distinguished from receptor sequestration. Finally, the internalised receptor is digested by proteolytic enzymes. The present article describes the basic patterns of molecular biology of beta-AR, signal transduction, and receptor desensitisation. In the human heart, beta-AR are the most important receptor system to provide positive inotropic and chronotropic effects. The alterations of the beta-adrenergic system in cardiac insufficiency, after heart transplantation, and after extracorporeal circulation, as well as changes induced by surgery and single anaesthetic agents, are reviewed.

Amino Acid Sequence↗
PubMed1996

[Specific risks of active compression-decompression in cardiopulmonary resuscitation: a case report].

Circulatory effects of cardiopulmonary resuscitation with active compression-decompression (CPR-ACD) are superior to the conventional technique. Decompression, thoracic expansion and a corresponding suction effect obviously improves cardiac preload. Due to significant or unphysiological thoracic expansion, thorax, diaphragma, and epigastrium are exposed to considerable traction powers. In a patient with fulminant pulmonary embolism, conventional cardiac massage and ACD were maintained during 65 minutes with simultaneous systemic thrombolytic therapy. After CPR, the patient developed a massive haemorrhagic shock. During emergency laparotomy, significant adhesions of upper abdominal organs with serious injuries of spleen and liver were found. Traction powers during CPR-ACD in combination with abdominal adhesions are considered responsible. Until improved outcome of CPR-ACD is demonstrated in larger clinical investigations, at least initially conventional cardiac massage should be preferred before the ACD-technique is used. Special attention to patients with a history of upper abdominal operations or chronic inflammatory lung diseases is mandatory.

Cardiopulmonary Resuscitation↗
PubMed1996

[Blood supply to the liver in the human after 1 MAC desflurane in comparison with isoflurane and halothane].

OBJECTIVE: Objective of this investigation was to compare the effects of the new inhalation agent desflurane with equipotent doses of isoflurane and halothane on hepatic blood flow (tHBF). METHODS: 36 Patients scheduled for elective aortocoronary bypass grafting were enrolled to the study. tHBF was assessed by plasma clearance and hepatic extraction of indocyanine green, and standard haemodynamic parameters were measured by thermodilution technique. The measurements were performed awake and after intubation at equilibration of 1 MAC. All measurements were terminated before skin incision. RESULTS: We found a significant decrease of tHBF in all patients regardless of the inhalation agent used (H 918 ml/min +/- 107 to 625 ml/min +/- 181, I 930 ml/min +/- 195 to 637 ml/min +/- 137, D 940 ml/min +/- 129 to 677 ml/min +/- 122). The tHBF in relation to cardiac output also decreased significantly (H 17% +/- 5 to 14% +/- 3, I 16% +/- 3 to 14% +/- 5, D 20% +/- 5 to 18% +/- 6). No difference was seen between the groups according to tHBF and haemodynamics. CONCLUSION: The results of this study suggest that all inhalation agents included in the study significantly decreased tHBF during anaesthesia with the concentration of 1 MAC.

Aged↗
PubMed1996

[Effects of different kinds of ventilation and positioning measures on blood flow velocity in the middle cerebral artery].

OBJECTIVE: Aim of the present study was to quantify the influence of varying respiratory parameters and different body positionings on transcranial Doppler sonography (TCD) values. With the approval of the local ethics committee, 34 patients without neurological deficits scheduled for an operation in supine position (n = 15) and in the so-called "rabbit-position" (RP, n = 19) were chosen for a prospective randomised investigation. METHODS: Prior to induction of anaesthesia, during the study and after extubation, the systolic (Vs), diastolic (Vd) and mean (Vm) of blood flow velocities as well as pulsatility (Vs - Vd)/Vm of the middle cerebral artery were determined by TCD. In addition mean arterial pressure and heart rate were monitored. Pulmonary airway pressures were observed during anaesthesia and CO2-partial pressure and central venous pressure (CVP) were determined by central venous line and blood samples. Anaesthesia was initiated with 5 mg/kg thiopental and continued with 0.8-1.2 vol% isoflurane in N2O/O2 = 2:1. After positioning all variables were recorded at 10-minute intervals with an inspiratory:exspiratory (I:E) ratio of 1:2, positive endexspiratory pressures (PEEP) of 0 and 10 cm H2O and an I:E ratio of 1:1 with 0 and 10 cm H2O PEEP. The respirator was adjusted to maintain an endtidal pCO2 of 40 mmHg. RESULTS: Neither different positioning of the patients, nor the alteration of respiratory parameters affected TCD variables in a significant way. No significant alterations were detected between the two groups of patients. Rising PEEP resulted in a minor but significant increase in CVP by an average of 3 cm H2O in both groups. The respective positions produced different respiratory pressures. These were in the "RP-group", with and without PEEP, at an approximately 5 cm H2O higher level. All other parameters did not vary significantly. CONCLUSION: The findings of this study show that a positioning of patients in a so-called "rabbit position" during anaesthesia does not alter the rate of blood flow velocity in the middle cerebral artery. Moreover, the modification of important respiratory parameters, especially a rise of PEEP to 10 cm H2O, had no significant influence on TCD values.

Adult↗