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H Forst

Publications and source records attributed to H Forst.

At least 37 records · Page 2Linked to original sources

A comparison of the adrenocortical response during septic shock and after complete recovery.

OBJECTIVE: To compare the adrenocortical response to corticotropin during septic shock and after complete recovery. DESIGN: Prospective clinical study. SETTING: Multidisciplinary intensive care unit in a university hospital. PATIENTS: 20 consecutive patients surviving septic shock. All patients met the American College of Chest Physicians/Society of Critical Care Medicine criteria for septic shock. In addition, the presence of high-output circulatory failure with a cardiac index > 41/min per m2 was a criterion for enrollment in the study. Complete recovery from septic shock was defined as discontinuation of any supportive therapies. Severity of illness during septic shock and after recovery was graded using the Acute Physiology and Chronic Health Evaluation (APACHE) II scoring system. INTERVENTIONS: In each patient, two short corticotropin stimulation tests were done during septic shock and after recovery. MEASUREMENTS AND RESULTS: Basal cortisol levels recorded during septic shock and after recovery did not differ (medians: 18.8 vs 18.9 micrograms/dl). However, the response to corticotropin was significantly attenuated during septic shock when compared with the response after recovery (medians: 7.7 vs 14.7 micrograms/dl; p = 0.02). After recovery, patients' stress response was less, as indicated by a reduction in APACHE II scores (medians: 21 vs 5 points; p < 0.01). CONCLUSIONS: Adrenocortical response to corticotropin is attenuated in patients with septic shock and high-output circulatory failure compared to the response in the much less stressful condition after recovery. The attenuated adrenocortical responsiveness may be explained by effects of circulating mediators from the systemic inflammatory response.

APACHE↗

[Venovenous extracorporeal membrane oxygenation (ECMO) with a heparin-lock bypass system. An effective addition in the treatment of acute respiratory failure (ARDS)].

Mortality of severe acute respiratory distress syndrome (ARDS) in Germany is about 60%. Respiratory therapy can make the lung injury worse by high positive airway pressures, high tidal volumes and high inspiratory oxygen concentrations. Extracorporeal membrane oxygenation (ECMO) was employed to reduce aggressive mechanical ventilation, but it has not been proved to be superior to conventional ventilation. However, encouraged by recently developed improvements in the technique and concept of ECMO, we introduced this therapy into our program for the treatment of ARDS. PATIENTS AND METHODS. All patients with severe ARDS (lung injury score > 2.5) admitted to our multidisciplinary intensive care unit from March 1992 to March 1995 were evaluated prospectively. After admission, the patients first underwent a conventional therapeutic approach, including pressure-controlled inverse-ratio ventilation, permissive hypercapnia, changes in body position (in particular, the prone position), negative fluid balance, anti-biotics, and low-dose hydrocortisone infusion. ECMO via a covalently heparin-coated, venovenous bypass-system with a vortex pump and two membrane lungs was performed if ARDS did not improve after 24-96 h of conventional therapy and if two of three of the slow-entry criteria for ECMO were fulfilled: (1) PaO2/FiO2 < 150 mmHg at PEEP > 5 mbar; (2) semistatic compliance < 30 ml/mbar; (3) right-left shunt > 30%. Only in cases of life-threatening hypoxemia (PaO2 < 50 mmHg at FiO2 1.0 and PEEP > 5 mbar for > 2 h (fast-entry criteria) was ECMO instituted immediately. RESULTS. Sixty patients fulfilled the entry criteria for our study. Thirty-nine patients were treated with a conventional protocol, 37 after improvement of ARDS and 2 who had not improved but in whom there were contraindications to the use of ECMO. ECMO was performed in 10 patients who had not improved, but who fulfilled the slow-entry criteria and in 11 primarily hypoxemic patients who fulfilled the fast-entry criteria. The survival rate was 30/39 (77%) for the conventional therapy group, 6/10 (60%) for the slow-entry group, and 11/11 (100%) for the fast-entry group. The onset of ECMO allowed a significant decrease in peak and mean airway pressures, tidal volume, ventilatory rate, minute volume and inspiratory oxygen concentration. Sufficient gas exchange was provided, and pulmonary artery pressures significantly decreased on bypass. The most frequent complications on bypass were pneumothorax (15/21 patients) and bleeding (7/21 patients). CONCLUSION. In comparison with the historical results at our own institution, the present study demonstrates an improvement in the survival rate from 56% to 78% since ECMO has become available. We conclude that venovenous ECMO with a heparin-bonded bypass circuit is an effective additional option for the treatment of patients with severe ARDS.

Adolescent↗

[Are high risk patients candidates for minimally invasive surgery with CO2 pneumoperitoneum? Viewpoint from anesthesiology].

As laparoscopic techniques show definite advantages in terms of pain and postoperative pulmonary function, high-risk patients especially benefit from such procedures. Pathophysiological changes caused by the pneumoperitoneum can be managed with invasive monitoring and resulting therapy. The increase in systemic vascular resistance with reduction in cardiac output can be kept to a minimum using low intraabdominal pressures (8-10 mmHg) under adequate muscular relaxation. Additional peripheral vasodilators and positive inotropic medication may be necessary. As the adverse hemodynamic effects end almost instantaneously with the reduction of the intraabdominal pressure, it is allways possible to revert to an open procedure after a laparoscopic try. If ventilation can not be increased adequately to maintain isocapnia in a patient suffering from pulmonary disease, the resulting increase in paCO2 will usually be moderate. In some instances it may be necessary to prolong artificial ventilation postoperatively, until isocapnia is reached with minuteventilation as at the beginning of anaesthesia.

Hemodynamics↗

Hepatitis C virus infection as a possible risk factor for ductopenic rejection (vanishing bile duct syndrome) after liver transplantation.

Irreversible ductopenic rejection (DR) after orthotopic liver transplantation (OLT) is a major cause of late hepatic allograft failure. A variety of risk factors for DR have been postulated, but they are controversial. All transplant recipients at our institution with graft survival of more than 1 month (n = 120) were examined retrospectively with a view to possible risk factors for DR. These factors included age, sex, underlying liver disease, hepatitis B and C infections, donor-recipient CMV status, post-OLT CMV infections, immunosuppressive regimen, ABO blood type, and HLA class I and class II mismatches. Statistical analysis was performed with the univariate chi-square test or the two-tailed Fischer's exact test. Ten patients (8.3%) developed DR. Seventeen patients had HCV infections after OLT. In this group, the incidence of DR was highest (4 of 17, or 23.5%). This was significantly higher than for all other OLT groups (6 of 103 patients, or 5.8%; P < 0.03). The other factors analyzed did not reach statistical significance, including those that other authors found important for the development of DR. It may well be that hepatitis C infection predisposes one to the development of DR after OLT.

Bile Duct Diseases↗

Risk factors for systemic fungal infections in liver transplant recipients.

The risk factors for systemic fungal infections were analysed retrospectively in 186 orthotopic liver transplant procedures performed in 152 patients between June 1985 and January 1993. The total incidence of systemic fungal infections was 16.5% (25/152). The incidence of disseminated candidiasis, aspergillosis, and combined candidiasis and aspergillosis was 6.5% (n = 10), 7.2% (n = 11) and 2.6% (n = 4), respectively. Mortality associated with systemic fungal infections was 80% (20 of 25 patients). There were ten cases of disseminated candidiasis, with 4 patients surviving, and 11 cases of invasive aspergillosis, with 1 patient surviving. All patients with combined systemic fungal infection died. To identify perioperative risk factors, 39 variables were used to compare patients with systemic fungal infections versus those without fungal infections. Fourteen variables were significantly associated with systemic fungal infections by univariate analysis. A consecutive logistic regression analysis revealed that the amount of fresh frozen plasma transfused due to poor initial function of the allograft and acute renal failure requiring hemofiltration were independently significant risk factors for systemic fungal infections. There was no statistical correlation between systemic fungal infections and the underlying liver disease, previous long-term corticosteroids and the postoperative immunosuppressive therapy. Risk factors identified in this study should be considered in the postoperative care of the individual liver transplant recipient. In our study a poor initial function of the hepatic allograft substantially increased the risk of systemic fungal infection.

Adult↗

The predictive value of four scoring systems in liver transplant recipients.

OBJECTIVE: To compare 4 general severity classification scoring systems concerning prognosis of outcome in 123 liver transplant recipients. The compared scoring systems were: the mortality prediction model (admission model and 24 h model); the simplified acute physiology score; the acute physiology and chronic health evaluation (Apache II) and the acute organ systems failure score. DESIGN: Retrospective, consecutive sample. SETTING: Adult intensive care unit in a university hospital. PATIENTS: 123 adult liver allograft recipients after admission to the intensive care unit. MEASUREMENTS AND MAIN RESULTS: The scoring systems were calculated as described by the authors to classify the severity of illness after admission of the allograft recipients to the intensive care unit. The mean and median values of survivors and the group of patients, that died during hospital stay were compared. Receiver-operating characteristics were plotted for all scoring systems and the areas under the curves of receiver-operating characteristics were calculated. The predictive value of the 4 scoring systems was tested using a variety of sensitivity analyses. The mortality prediction model (24 h model) was found to have a high significance (p < 0.001) in predicting mortality and showed the greatest area under the curve (0.829). Simplified acute physiology score (p < 0.001) and acute physiology and chronic health evaluation (Apache II) (p < 0.01) had a high significance as well, but did not hit the level of prognosis of mortality prediction model, as shown in the area under the curves. Accordingly, sensitivity was highest in MPM-24 h (83%), followed by SAPS (72%) and Apache II (71%). MPM-24 h had a total misclassification rate of 22% (SAPS = 32%, Apache II = 33%). MPM-admission failed in predicting mortality (sensitivity = 52%). Organ systems failure score seemed not to be useful in liver transplant recipients. CONCLUSION: General disease classification systems, such as the mortality prediction model, simplified acute physiology score or acute physiology and chronic health evaluation are good mortality prediction models in patients after liver transplantation. We suggest that there is no need for improvement of a special scoring system.

Adolescent↗

[Continuous measurement of cardiac output with pulse contour analysis].

Pulse contour cardiac output (PCCO) is an easily applicable method for continuous measurement of cardiac output in critically ill patients. Calculation of stroke volume is possible by analysing the area under the systolic part of the arterial pulse pressure waveform together with an individual calibration factor (Zao) to account for the individually variable vascular impedance. Since vascular impedance is potentially affected by altered vascular tone, it was the aim of the present study to examine the validity of PCCO in ICU patients receiving various dosages of a variety of vasoactive drugs. PATIENTS AND METHODS. Continuous cardiac output was measured in 20 ICU patients for a total of 110 h using the pulse contour method. The precision of PCCO was determined in comparison with its calibration reference, the thermodilution method (TDCO): (1) during administration of vasoactive drugs at a constant rate and (2) during conditions with altered vascular tone and haemodynamics elicited by changes in vasoactive drug dosage. For this purpose, the patients received varying dosages of vasoactive drugs (dopamine, dobutamine, epinephrine, norepinephrine, nitroglycerin, prostacyclin and urapidil). RESULTS. A total of 165 data sets was obtained, each consisting of the average of four capnometrically triggered TDCO measurements and the corresponding PCCO values. The relative difference between methods (+/- 2 SD) was +/- 23.9% (SD 0.85 l.min-1; r = 0.93) if a single calibration at the beginning of measurement series was performed (Fig. 2). The bias of the mean cardiac output values of both methods was -0.09 l.min-1. The precision of PCCO improved to +/- 15.7% by additional calibrations (SD 0.56.min-1; r = 0.96; bias 0.003 l.min-1). Data of two patients showed that recalibration may be necessary after extreme haemodynamic changes due to septic shock or cooling. Alteration of vascular tone by clinically used dosage of vasoactive drugs, however, had no destabilizing effect on the pulse contour method. CONCLUSIONS. It could be demonstrated that PCCO provides a valuable method for continuous cardiac output measurement in the intensive care setting with a precision comparable to that of thermodilution.

Adult↗

Evaluation of a new continuous thermodilution cardiac output monitor in critically ill patients: a prospective criterion standard study.

OBJECTIVE: To evaluate the accuracy of a new continuous cardiac output monitor (one based on the thermodilution principle) in critically ill patients. DESIGN: Criterion standard study. SETTING: Multidisciplinary intensive care unit in a university hospital. PATIENTS: Fourteen critically ill patients, with different diseases, requiring pulmonary artery catheterization. INTERVENTIONS: In two patients with a left ventricular assist system, a defined, sudden 1 L/min change in cardiac output was carried through to evaluate the in vivo response time of the continuous cardiac output monitoring system. In the remaining 12 patients, cardiac output was altered by varying the dose of catecholamines, by volume loading, or by varying the level of sedation. In four patients, a rapid infusion of cold saline was given through a central venous catheter to test the performance of the system under these conditions. MEASUREMENTS AND MAIN RESULTS: Cardiac output was monitored continuously. A total of 163 (13 to 18 per patient) bolus determinations of cardiac output were performed, using the conventional thermodilution technique and simultaneously using the indocyanine green dye dilution technique. The range of cardiac output was 3.8 to 15.6 L/min. The results of the continuous thermodilution method were compared with the results of the bolus thermodilution and the dye dilution methods, respectively. The mean difference (bias) +/- SD of differences (precision) was 0.35 +/- 1.01 L/min for continuous vs. bolus thermodilution and 0.34 +/- 1.01 L/min for continuous thermodilution vs. indocyanine green dye dilution. Linear regression (correlation) analyses were y = 0.95x + 0.76 (r2 = .91) for continuous and bolus thermodilution and y = 0.93x + 0.87 (r2 = .91) for continuous thermodilution and dye dilution. The 75% in vivo response time was 10.5 mins. The infusion of cold isotonic saline led to erroneous continuous cardiac output values. When the conventional bolus thermodilution and dye dilution techniques were compared, mean difference was -0.01 +/- 0.54 L/min and the results of linear regression analyses were y = 0.97x + 0.22 (r2 = .97). CONCLUSIONS: Continuous cardiac output measurement using the thermodilution technique is reasonably accurate and is reliable and applicable in routine clinical practice, and therefore may add to patient safety. However, the response time is too slow for the immediate detection of acute changes in cardiac output. Some clinical conditions such as the rapid infusion of cold solutions can interfere with the continuous cardiac output measurement. Conventional bolus thermodilution and indocyanine green dye dilution methods showed good agreement and can be used interchangeably.

Adult↗

Thermodilution cardiac output may be incorrect in patients on venovenous extracorporeal lung assist.

Cardiac output measurement is part of routine monitoring in critically ill patients. In patients on extracorporeal lung assist, thermodilution cardiac output measurement may lead to erroneous results caused by indicator loss into the extracorporeal circuit. Seven patients on venovenous extracorporeal lung assist were studied using different extracorporeal blood flows. We compared conventional thermodilution cardiac output determinations with dye dilution cardiac output measurement, with dye injection into the pulmonary artery. The latter method is not affected by the extracorporeal circuit. The conventional thermodilution method overestimated cardiac output up to a maximum of 300%, providing results up to 10 L/min higher than true cardiac output. The mean difference between thermodilution and true cardiac output as determined by dye dilution with pulmonary artery indicator injection was 3.0 +/- 2.41 L/min. There was no correlation between thermodilution cardiac output values and true cardiac output (r = 0.06). We conclude that conventional thermodilution is not a suitable method for cardiac output measurement in patients on extracorporeal lung assist, especially if high extracorporeal blood flows are applied.

Adult↗

[Noninvasive ventilation after lung transplantation].

BACKGROUND: Non-invasive mechanical ventilation (NIPPV) is an accepted choice of treatment in patients with chronic pulmonary disease and/or acute respiratory failure. Recently NIPPV was also proposed in the postoperative weaning period. PATIENTS AND METHODS: Six of 30 patients after lung transplantation were were extubated despite a weaning failure was predicted using well accepted weaning criteria. Therefore, the 6 patients were treated with intermittent-noninvasive ventilation using assisted modes of mechanical ventilation (PSV/CPAP). RESULTS: Both, oxygenation (increase in paO2: 18 mm Hg during PSV, 11 mm Hg during CPAP) and pulmonary mechanics (decrease in respiratory rate: 14/min during PSV, 10/min during CPAP; increase in tidal volume: 5 ml/kg during PSV, 3 ml/kg KG during CPAP) improved and the energy expenditure decreased (19% during PSV, 12% during CPAP). CONCLUSION: Non-invasive ventilation after lung transplantation enables earlier extubation and prevents weaning failure.

Humans↗

[Isolated lung transplantation. Analysis of 17 consecutive operations. Munich Lung Transplant Group].

16 patients (nine men, seven women; mean age 45 [23-62] years) with end-stage pulmonary disease underwent lung transplantation, 14 unilateral, three bilateral (one bilateral retransplantation). The diagnoses were: emphysema (n = 5), idiopathic pulmonary fibrosis (n = 5), emphysema in alpha 1-antitrypsin deficiency (n = 1), mucoviscidosis (n = 1), drug-induced fibrosis (n = 1), chronic lung rejection after heart-lung transplantation (n = 1), secondary pulmonary hypertension with persistent ductus arteriosus (n = 1), sarcoidosis (n = 1) and chronic transplant failure after unilateral transplantation (n = 1). Eleven patients survived long-term (mean follow-up period 247 [8-585] days). Ten of these patients have been independent of additional oxygen after an average of 8 months postoperatively, eight are physically active according to their age. Three patients died of reperfusion damage intraoperatively or in the early postoperative period. The two other patients died from septicaemia 5 1/2 and 7 months postoperatively. It is concluded that lung transplantation in end-stage pulmonary disease provides the only therapeutic means with any expectation of physical rehabilitation.

Activities of Daily Living↗

Low-dose hydrocortisone infusion attenuates the systemic inflammatory response syndrome. The Phospholipase A2 Study Group.

There is increasing evidence that the hypercortisolemia in inflammatory diseases suppresses the elaboration of proinflammatory cytokines, thus protecting the host from its own defence reactions. In severe sepsis and septic shock cortisol levels are usually elevated, but some patients may have relative adrenal insufficiency. This may contribute to the overwhelming systemic inflammatory response syndrome. We evaluated the impact of low-dose hydrocortisone infusion (10 mg/h) on the course of the systemic inflammatory response syndrome. This dose corresponds to a maximum secretory rate of cortisol achieved in corticotropin-stimulated healthy humans. In a prospective observational study 57 surgical patients with severe sepsis or septic shock were studied, of which in addition to the conventional treatment 12 patients were infused with low-dose hydrocortisone, and 45 were treated without any corticosteroid. In the longitudinal analysis the systemic inflammatory response--as judged by body temperature, cardiovascular response, and kinetics of inflammatory mediators such as phospholipase A2, C-reactive protein, and neutrophil elastase--started to differ in favor of the hydrocortisone-treated patients after 2 days of treatment (P < 0.05, Mann-Whitney U test). The difference disappeared after withdrawal of exogenous cortisol. Shock reversal was achieved in all patients treated with low-dose hydrocortisone. The data provide evidence that low-dose hydrocortisone infusion attenuates the systemic inflammatory response in human septic shock. From an immunological point of view a relative cortisol deficiency may contribute to the amplified immune response in systemic inflammatory diseases. A randomized clinical trial must clarify the impact of low-dose hydrocortisone infusion on the clinical course and outcome of septic shock patients.

Adrenal Insufficiency↗

[Continuous intravascular blood gas analysis. Clinical evaluation of a new fiber optic monitor].

Continuous monitoring of blood gases and pH could add substantially to patient safety. During the last decade, efforts have been made to develop continuous optochemical blood gas sensors. The initial evaluation of such fibreoptic-based systems showed major patient-interface problems [11]. We evaluated a new intra-arterial blood gas monitoring system (PB3300, Puritan-Bennett, Carlsbad CA) under routine clinical conditions. METHODS. After institutional review board approval and with written informed consent, 38 sensors were tested in 25 patients with acute respiratory failure (e.g., the acute respiratory distress syndrome, complications after lung transplantation). Two conventional bench-top blood gas analysers (ABL 520 and ABL 300, Radiometer, Copenhagen) served as criterion standards. The mean differences (bias) and standard deviations (SD) of the differences (precision) were calculated according to the method of Bland and Altman [2]. In addition, linear regression analysis and correlation coefficients were calculated. The quality of blood pressure tracings was assessed using a grading system. RESULTS. The median sensor lifetime was 81.3 h; 869 blood samples (median 14 per sensor) were analysed for the comparison of continuous and conventional blood gas analysis. The ranges for measured parameters were: pH: 6.92 to 7.55; PCO2: 20 to 83 torr; PO2: 31 to 518 torr. The mean differences (SD) were: pH: -0.03 (0.03) or -0.4 (0.4)%; PCO2: -2.6 (4.1) torr or -6.9 (10.9)%; PO2: -3.4 (10.5) torr or -2.9 (7.0)%. The results of linear regression analysis and the correlation coefficients are depicted in Table 2. The mean grade of blood pressure tracings was satisfactory for the clinical setting. CONCLUSIONS. The continuous blood gas monitor is sufficiently accurate and precise for clinical use. Bias and precision are better than those known from former studies evaluating fibreoptic blood gas monitors under experimental conditions [7]. Cost-effectiveness was not an issue of this study.

Blood Gas Analysis↗

Stent-angioplasty of an anastomotic stenosis of the pulmonary artery after lung transplantation.

Anastomotic stenosis of the pulmonary artery after lung transplantation is a rare complication, which commonly necessitates surgical correction. Transesophageal Doppler sonography and pulmonary arteriogram are standard diagnostic means for visualization of venous and arterial anastomoses. Balloon dilatation combined with implantation of a vascular endoprosthesis was successfully used for treatment of severe anastomotic stenosis of the pulmonary artery after lung transplantation.

Anastomosis, Surgical↗

[Radiological diagnosis in lung transplant patients].

Based on the imaging studies obtained from 13 patients after lung transplantation, radiological findings have been correlated with the clinical charts. The intention was to describe the radiological manifestations of the particular transplant complications of these patients. 12 episodes of reimplantation response were seen in the early postoperative period as a perihilar accented perivasal consolidation with typically short-termed appearances. 16 episodes of acute rejection showed various manifestations on the radiographs. They were characterised by immediate response to a bolus therapy with corticosteroids. This decisive observation allows the exclusion of other causes contributing to a condition following thoracotomy with similar radiological manifestations. Stenoses of the pulmonary or the bronchial anastomoses occurred once each and were confirmed in the course of further examinations. Chest radiograph proved to be the appropriate tool for the diagnosis of technical complications following iatrogenic measures (pleural effusion, pneumothorax). Clinical symptoms and follow-up observations are necessary for the interpretation of the radiographs. Chest radiography represents an important help concerning problems in differential diagnosis and further therapeutic decisions.

Acute Disease↗

Continuous intra-arterial blood gas and pH monitoring in critically ill patients with severe respiratory failure: a prospective, criterion standard study.

OBJECTIVE: To evaluate the routine clinical performance of a new intra-arterial fiberoptic blood gas sensor that provides continuous PO2, PCO2, and pH monitoring. DESIGN: Criterion standard study under routine clinical conditions. SETTING: Intensive care unit (ICU) in a university hospital. PATIENTS: Twenty-two sensors were tested in 13 patients with acute respiratory failure, including two patients receiving veno-venous extracorporeal lung assist. Patient selection was based on the necessity of frequent blood gas monitoring. MEASUREMENTS: Sensor-deprived PO2, PCO2, and pH values were compared with values obtained using two different conventional laboratory blood gas analyzers located in the ICU. The median study period was 72 hrs per sensor (range 8 to 170 hrs). The quality of blood pressure readings with the sensor introduced through the arterial catheter was assessed by a grading system. RESULTS: Mean differences between sensor-derived values and the average values of the two conventional blood gas analyzers were as follows: PO2 -2.4 +/- 6.5 (SD) torr (-0.3 +/- 0.9 kPa), PCO2 -2.9 +/- 3.9 torr (-0.4 +/- 0.5 kPa), and pH -0.04 +/- 0.03. Correlation coefficients were 0.99 (PO2), 0.94 (PCO2), and 0.89 (pH), respectively. The agreement between the two methods for PO2 measurement was better for the clinically important range of values (PO2 < 150 torr [< 20 kPa]) than for all measured PO2 values (range 30 to 522 torr [4 to 69.6 kPa]). Blood withdrawal and pressure readings were not adversely affected by the sensor. No side effects due to the insertion of the sensor were observed. CONCLUSIONS: The degree of agreement of intra-arterial blood gas sensor values with conventional blood gas analysis is within an acceptable range for routine clinical purposes. Acute changes in measured values are detected reliably. Continuous intra-arterial blood gas analysis can add substantially to the safety of patients with acute respiratory failure and can reduce blood sampling requirements for blood gas analysis.

Adolescent↗