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Description / Table of Contents: Abstract. Automated measurements of respiratory gas exchange recently became available for the determination of oxygen uptake (V˙O2) in critically ill patients. Whereas these metabolic gas monitoring systems (MBM) are assumed to measure total body V˙O2, the reversed Fick method in principle excludes intrapulmonary V˙O2. Previous clinical reports comparing V˙O2 measured by the reversed Fick principle (V˙O2  Fick) with V˙O2 measured by MBM (V˙O2  MBM) found that V˙O2  MBM was significantly greater than V˙O2  Fick. It was suggested that these differences between methods represent V˙O2 of pulmonary and bronchial tissue, as intrapulmonary V˙O2 had been estimated to account for 15% of total body V˙O2 in dogs with experimental pneumonia. The objective of this study was to compare V˙O2  Fick with V˙O2  MBM in patients with and without pneumonia and to assess the reproducibility of both methods in critically ill patients. Method. With institutional approval nine critically ill patients with acute pneumonia were studied under controlled mechanical ventilation. The diagnosis of pneumonia was based on respective changes of chest X-rays, body temperature 〉38 °C, and WBC counts 〉12,000/mm3. Inspiratory oxygen fractions (FIO2) ranged from 0.3 to 0.6; all patients routinely received opioids and hypnotics. Complete muscle relaxation was achieved during the periods of measurement to avoid sudden changes in V˙O2 due to shivering or involuntary movements. Arterial and pulmonary-arterial blood samples were drawn simultaneously after aspiration of the sevenfold catheter dead space. Measurements of haemoglobin concentration (Hb), fractional oxygen saturation (SO2), and O2 partial pressure (PO2) were performed by use of a calibrated haemoximeter and blood gas analyser, respectively; 2×5 thermodilution measurements of cardiac output (CO) were spread randomly over the respiratory cycle for each determination of V˙O2  Fick. To minimise systematic errors of CO measurements, the CO computer was calibrated in an extracorporeal model using an electromagnetic flowmeter. Calculations of V˙O2  Fick were based on an oxygen binding capacity of 1.39 ml/g Hb. Simultaneous measurements of V˙O2  MBM were obtained by use of a Datex Deltatrac MBM that had been validated in vitro with a gas dilution model of respiratory gas exchange. Calibration of the MBM was performed prior to each measurement. Gas supply of the respirator was provided by an external high-precision mixing device to reduce errors in V˙O2 measurements that may arise from short-term oscillations in FIO2. All patients with pneumonia were studied on three consecutive days; thus, measurements from 27 days could be analysed. On each day two sets of measurements were performed at an interval of 60 min to assess the reproducibility of differences between methods. During each set of measurements duplicate blood samples were drawn twice, before and after thermodilution measurements of CO, to evaluate the short-term repeatability of V˙O2  Fick. The beginning and the end of each set of measurements were marked in the computer record of the MBM to assess the respective repeatability of V˙O2  MBM. Fifty control measurements were performed in ten patients undergoing major neurosurgical procedures. None of these patients exhibited signs of pulmonary infection. Except for the number of repeated measures, all V˙O2 measurements were obtained in the same way as in the study group. Descriptive statistical analysis was performed according to Bland and Altman; comparisons between methods were done by multivariate analysis of variance for repeated measures. Results. Neither in the study group nor in the control group could a significant difference between methods be demonstrated. In patients with pneumonia the mean difference between methods (V˙O2  Fick−V˙O2  MBM) was 15.2 ml/min (4.2%); the double standard deviation of differences (2 SD) was 59.2 ml/min (19.2%). Control patients exhibited a mean difference of 7.2 ml/min (3.1%); 2 SD was 41.1 ml/min (20.4%). Duplicate determinations of V˙O2  Fick and V˙O2  MBM within one set of measurements showed a repeatability coefficient (2 SD of differences between repeated measures) of 43.8 ml/min (13.2%) and 15.3 ml/min (5.1%), respectively. The large variation of duplicate measurements of V˙O2  Fick was caused rather by the variability of arteriovenous O2 content determinations than by the variability of CO measurements. Discussion. These results are in contrast to previous method comparison studies, which suggested that in infected lungs V˙O2 of pulmonary and bronchial tissue represents up to 15% of total body V˙O2. Since the mean differences between V˙O2  Fick and V˙O2  MBM did not differ between the two groups of patients, pulmonary infection did not seem to cause a considerable increase in intrapulmonary V˙O2. A minor effect of intrapulmonary V˙O2 on differences between methods cannot be excluded because of the variability of data. The poor repeatability of V˙O2  Fick measurements, however, seems to limit the use of method comparison studies for estimation of intrapulmonary V˙O2.

Description / Table of Contents: Abstract. Intrinsic positive end-expiratory pressure (PEEPi) occurring during mechanical ventilation depends on expiratory time constants, expiratory volume and expiration time as well as on external flow resistance (tubes, valves, etc.). It is not routinely determined in mechanically ventilated patients, but it is necessary to optimize respirator settings. The aim of the present study was the validation of an automated PEEPi determination method implemented in the respirator EVITA (Drägerwerke, Lübeck) in mechanically ventilated patients with acute lung failure. Patients. The method was validated in ten sedated, myorelaxed patients with respiratory insufficiency of different etiologies (five with restrictive, and five with obstructive pulmonary disease). PEEPi was determined using the volume constant ventilatory mode at ZEEP or at an external PEEP of 5 as well as 10 cm H2O. Method. PEEPi was first determined with the automated method implemented in the EVITA (five measurements at each end-expiratory pressure level; PEEPEvita). Steady-state was attained between each measurement. These values were compared to the results obtained with end-expiratory occlusion (external, computer-controlled valve in the inspiratory limb of the circuit) at the respective pressure levels (PEEPEEO). The average of five measurements at each PEEP level with each method was defined as PEEPi for the particular ventilatory situation. Gas flow was measured at the proximal end of the endotracheal tube with a heated pneumotachometer (Fleisch no. 2, Fleisch, Lausanne, Switzerland) and a differential pressure transducer. Tracheal pressure was determined in the same position with a further differential pressure transducer (Dr. Fenyves & Gut, Basel, Switzerland). After A/D conversion, data were sampled with a frequency of 20 Hz and processed on an IBM compatible PC. Software for data collection and processing as well as for control of the occlusion valve was self-programmed. For the statistical analysis we used the Mann-Whitney U-test or Wilcoxon signed-ranks test; a P value less than 0.05 was considered significant. Results. At the given respiratory setting and without PEEP patients with obstructive lung disease had a higher PEEPi (median: 6.4 cm H2O; range: 5.0 – 9.6 cm H2O) than those with restrictive pulmonary disease (median: 2.3 cm H2O; range: 0.8 – 3.0 cm H2O) (P〈0.05). Increasing external PEEP to 5 or 10 cm H2O significantly decreased the pressure difference between PEEPi and external PEEP (P〈0.05), but was unable to eliminate it completely. There was no statistically significant difference between PEEPEEO and PEEPEvita (P=0.43; Wilcoxon signed-ranks tests). Regression analysis showed a highly significant correlation between PEEPEEO and PEEPEvita values (r=0.985, P〈0.001; y=1.03x−0.18). Discussion. PEEPi occurs during ventilation in patients with obstructive and restrictive lung disease. The difference between external end-expiratory pressure and PEEPi decreases with increasing external PEEP. However, PEEPi may increase with increasing external PEEP in some instances. The reason for this may be that the PEEPi determined at the proximal end of the endotracheal tube represents only a mean value of different PEEPi values of various lung regions. Increasing external PEEP only partially alters this mean value due to an effect on PEEPi values lower than external PEEP. The PEEPi values measured by the EVITA respirator compared with classical end-expiratory occlusion with an external valve were nearly identical. Unfortunately, PEEPi measurement of the EVITA can only be performed during controlled and not during assisting (PSV, BIPAP etc.) ventilation. Optimal respirator settings require a knowledge of PEEPi (i.e., adaption of external PEEP for lowering the work of breathing in COPD patients or prolongation of the expiratory phase to avoid unwanted side effects of an occult PEEPi on the circulation). Since modern microprocessor-controlled respirators can easily be updated with the necessary equipment, measurement of PEEPi should be a part of routine ventilatory monitoring today.

Description / Table of Contents: Abstract. Total intravenous anaesthesia (TIVA) using a combination of a hypnotic and an analgesic agent is gaining increasing popularity as an alternative to balanced anaesthesia with volatile anaesthetics for abdominal surgery. Among the required characteristics of the drugs used in this technique are a good correlation between dose, plasma concentrations, and effect as well as rapid elimination from the circulation, allowing close control of anaesthetic depth. Two hypnotic drugs with similar pharmacokinetic and pharmacodynamic profiles are propofol and methohexitone, both of which can be employed as a component of a TIVA technique. Two TIVA combinations utilising either of these drugs with alfentanil were tested against isoflurane-nitrous oxide in a balanced regimen. Methods. Twenty-seven healthy women undergoing hysterectomy for non-malignant diseases participated in the study after having given written consent. They were randomly allocated to receive either isoflurane (Iso), methohexital-alfentanil (M-A), or propofol-alfentanil (P-A). Blood samples for determination of cortisol, prolactin, catecholamines, glucose, lactate, non-esterified fatty acids, and pharmacon concentrations were drawn repeatedly from before induction until 360 min after surgery. Anaesthesia was induced in group Iso with fentanyl 0.1 mg and M 1.5 mg⋅kg−1 and maintained with Iso-N2O. In the TIVA groups M or P was given in a two-step infusion to load peripheral compartments and then maintain plasma concentrations within the hypnotic range. A was given as a continuous infusion in an identical dose (0.1 mg⋅kg−1 initial, 0.125 mg⋅kg−1⋅h−1 maintenance) in both groups. If signs of insufficient depth of anaesthesia occurred (heart rate or systolic blood pressure 〉25% above baseline), then first A (0.5 – 1 mg), and if that was ineffective, then 50 mg hypnotic was administered. The A infusion was stopped 30 min before the end of surgery, and Iso or the hypnotic was stopped at skin closure. Recovery time was the time until the patients were able to give their birth date after stopping the Iso or hypnotic. Results. The three groups were comparable with regard to age, weight, and duration of surgery. The total doses of M and P were 1,357±125 mg (mean±SEM) and 1,315±121 mg, respectively, and the total A doses were 20.7±2.5 mg (M-A) and 23.4±3.5 (P-A). The peak plasma concentrations were P 10.6±1.5 µg⋅ml−1 and M 12.4±2.6 µg⋅ml−1. At the end of surgery the P concentrations were in the projected range while those of M were somewhat lower than expected (P3.7±0.4 µg⋅ml−1; M 3.5±0.6 µg⋅ml−1). Three patients each in the P-A and M-A groups required supplementary A injections. Five patients in the P-A group required additional bolus injections of the hypnotic as compared to 2 in the M-A group. The median recovery times were Iso 15 min, M-A 50 min, and P-A 25 min (P〈0.05). The incidence of shivering was Iso 3/9, M-A 5/9, and P-A 0/9 (P〈0.05); vomiting occurred with equal frequency in all groups (Iso 33%, M-A 33%, P-A 22%). The patients were somewhat more restless in group M-A. Systolic blood pressure dropped in a similar manner in all groups after induction of anaesthesia (Iso −31%, M-A −37%, P-A −36%) but recovered during surgery. The intraoperative response of cortisol (Iso +216%, M-A +92%, P-A +43%) and catecholamines (noradrenaline Iso +56%, M-A +30%, P-A −21%) was lower in the TIVA groups, whereas prolactin increased after induction in all groups. Plasma concentrations of glucose, lactate, and fatty acids were lower in the TIVA groups than in the Iso group intraoperatively, but increased to comparable postoperative levels. Conclusions. Both TIVA regimens are acceptable alternatives to balanced anaesthesia with Iso N2O. Both are similar with regard to haemodynamic, endocrine, and metabolic changes and are able to reduce the stress response more effectively than Iso N2O. Of the two, P seems to offer the advantage of a somewhat shorter recovery time, less shivering, and calmer patients in the immediate postoperative period, although M might be preferred if economic considerations are important.

Description / Table of Contents: Abstract. Fournier's gangrene is a necrotising soft-tissue infection of the scrotum and perineal region caused by gram-negative and gram-positive Enterobacteriaceae. The disease is characterised by its unique appearance, its speed of onset, and its high mortality. Case report. A 26-year-old male presented to the emergency room complaining of a painful, tremendously swollen scrotum and penis (Fig. 1) that had developed within the past 24 h. Later, slurred speech, pallor, and hypotension were recognised, leading to the patient's admission to the intensive care unit. Suspecting a severe internal haemorrhage, vigorous volume therapy was started using crystalloids and colloids until blood and fresh frozen plasma were available. One hour later, septic shock was presumed and therapy augmented by IV antibiotics, tracheal intubation, and mechanical ventilation. Despite all efforts, the patients condition deteriorated rapidly and he died a few hours later due to multiple organ failure in septic shock. Postmortem, a perforated external hemorrhoidal node was found to be the primary focus of sepsis. Microbiologic cultures revealed Escherichia coli in blood and tissue samples. Discussion. Fournier's gangrene is a rare disease; nevertheless, its clinical picture has to be recognised immediately in order to provide appropriate treatment in time. It occurs predominantly in males after minor trauma, colorectal or urological disease, and perineal or abdominal surgery. Fournier's gangrene usually begins with itching and pain in the scrotal region followed by swelling and dark-blueish discolouration of the scrotum and penis, occasionally including the lower abdominal wall. Fever and chills are usually present. The illness progresses to severe prostration and septic shock with a mortality of 20% – 50%. Tissue cultures mostly reveal E. coli, gram-positive enterococci, Pseudomonas, Proteus, and various anaerobes. The treatment should include immediate radical surgical debridement, IV administration of broad-spectrum antibiotics, and cardiopulmonary support. Conclusion. The dramatic course of Fournier's gangrene requires early recognition, extensive surgical debridement, as well as intensive care treatment in order to prevent irreversible septic shock.

Description / Table of Contents: Zusammenfassung 74 Patienten, die 1978, und 316 Patienten, die 1986 während offener Herzchirurgie in Stockholm, Schweden, Transfusionen erhielten, wurden in eine prospektive Studie aufgenommen und im Hinblick auf das Auftreten einer Non-A, Non-B-Posttransfusions-hepatitis, Serokonversion für Hepatitis C Virus-Antikörper (anti-HCV, C-100), Zeitspanne bis zur Serokonversion für anti-HCV und Verlauf der NANB/C-Posttransfusionshepatitis untersucht. Bei Patienten, die 1978 transfundiert worden waren, wurden Untersuchungen auf anti-HCV bis zu sechs Monate nach der Transfusion und bei 1986 Transfundierten bis zu einem Jahr nach Transfusion durchgeführt. Eine Serokonversion zu anti-HCV trat bei 54% der Patienten mit NANB-Posttransfusions-hepatitis ein, 7/15 (47%) der Patienten aus dem Jahr 1978 und 8/13 (62%) aus dem Jahr 1986. Die Serokonversion zu anti-HCV trat bei vier der 15 Patienten (27%) schon innerhalb einer Woche ein, bei 12 (80%) innerhalb acht Wochen und bei allen innerhalb 18 Wochen nach Beginn der Hepatitis. Bei den Patienten mit Hepatitis C, die eine Serokonversion entwickelten, lag der Quotient von ELISA Meßwert zu Grenzwert (Optical density/ Cut-off, OD/CO) in allen Fällen über 4,0. Ein Patient, bei dem nach der Transfusion stets normale Serum- Aminotransferase-Spiegel vorlagen, zeigte nach sechs Monaten eine Serokonversion. Er war vorübergehend anti-HCV positiv, der ELISA OD/CO- Quotient für anti-HCV betrug maximal 1,2; nach drei Jahren war er seronegativ. Bei neun der 15 Patienten (60%) war eine chronische Hepatitis nach Serokonversion für anti-HCV zu beobachten. Unter den 13 Patienten mit NANB-Posttransfusionshepatitis, die keine Serokonversion zeigten, entwickelten fünf eine chronische Hepatitis (38%).

Description / Table of Contents: Zusammenfassung In einer retrospektiven Studie wurden Häufigkeit und klinische Verläufe der akuten B-Hepatitis mit und ohne Koinfektion durch Hepatitis D Virus (HDV) in der Region Stockholm während zwei verschiedener Zeitphasen, September 1977 bis Oktober 1978 und November 1984 bis Oktober 1986, untersucht. Eine HDV-Koinfektion war bei 31/229 Patienten mit akuter HBV-Infektion (14%) aufgetreten. Zwischen den 70er und 80er Jahren waren keine Unterschiede in der Häufigkeit der Koinfektionen, die bei 12% und 15% lagen, festzustellen. 74% der 31 zusätzlich mit HDV infizierten Patienten waren i. v. Drogenabhängige. Insgesamt hatten 23/66 i. v. Drogenabhängigen (35%), die an einer akuten HBV-Infektion erkrankt waren, eine HDV-Koinfektion. Bei 63% der zusätzlich mit HDV infizierten Patienten war ein zweiphasischer Anstieg von Alanin Aminotransferase und Bilirubin im Serum zu beobachten; dies war nur bei 8% der nur mit HBV Infizierten der Fall (p〈0,001). Ein schwerer klinischer Verlauf der Hepatitis fand sich bei Patienten mit HDV-Koinfektion signifikant häufiger als bei Kranken, die nur durch HBV infiziert waren.