Major incidents and complications in otherwise healthy patients undergoing elective procedures: results based on 1.37 million anaesthetic procedures

BACKGROUND

Improved anaesthesia safety has made severe anaesthesia-related incidents, complications, and deaths rare events, but concern about morbidity and mortality in anaesthesia continues. This study examines possible severe adverse outcomes or death recorded in a large national surveillance system based on a core data set (CDS).

METHODS

Cases from 1999 to 2010 were filtered from the CDS database. Cases were defined as elective patients classified as ASA physical status grades I and II (without relevant risk factors) resulting in death or serious complication. Four experts reviewed the cases to determine anaesthetic involvement.

RESULTS

Of 1 374 678 otherwise healthy, ASA I and II patients in the CDS database, 36 met the study inclusion criteria resulting in a death or serious complication rate of 26.2 per million [95% confidence interval (CI), 19.4-34.6] procedures, and for those with possible direct anaesthetic involvement, 7.3 per million cases (95% CI, 3.9-12.3).

CONCLUSIONS

This is the first study assessing severe incidents and complications from a national outcome-tracking database. Annual identification and review of cases, perhaps with standardized database queries in the respective departments, might provide more detailed information about the cascades that lead to unfortunate outcomes.

[Combined simulation training: a new concept and workshop is useful for crisis management in gastrointestinal endoscopy]

INTRODUCTION

Crisis management as well as realistic emergency situations can be trained in the new developed simulation workshop "Gastrointestinal Endoscopy and Crisis Resource Management" by combining a full-scale simulator and the Erlanger Endoscopy Trainer. The aim of the current study was to evaluate the efficiency of the newly developed simulation workshop.

METHODS

Endoscopists with more than 12 months experience can train their endoscopic skills and crisis resource management with the help of different simulators. In addition, two different scenarios (GI bleeding with significant blood loss and sedation overdoses) embedded in a realistic surrounding (emergency room) have to be managed by the participants. Vital parameters, endoscopic skills, as well as personal interactions were recorded and graded.

RESULTS

100 participants took part in the newly developed workshop (between June and December 2003). The participants showed a significantly better endoscopic performance and a significantly better crisis management after the standardized training program.

CONCLUSIONS

Simulation training plays an essential role in aviation and minimizes the risk for human errors. In the current study it is clearly shown that simulation training is also useful in gastrointestinal endoscopy. The newly developed workshop may thus be of crucial importance to improve personal crisis management. Simulation also leads to an improvement of endoscopic and emergency skills. Accordingly, simulation training should be recommended or offered as an education option in gastrointestinal endoscopy.

High-frequency oscillatory ventilation and an interventional lung assist device to treat hypoxaemia and hypercapnia

A male patient accidentally aspirated paraffin oil when performing as a fire-eater. Severe acute respiratory distress syndrome (Pa(o(2))/Fi(o(2)) ratio 10.7 kPa) developed within 24 h. Conventional pressure-controlled ventilation (PCV) with high airway pressures and low tidal volumes failed to improve oxygenation. Hypercapnia (Pa(co(2)) 12 kPa) with severe acidosis (pH<7.20) ensued. Treatment with high-frequency oscillatory ventilation (HFOV) and a higher adjusted airway pressure (35 cm H(2)O) improved the Pa(o(2))/Fi(o(2)) ratio within 1 h from 10.7 to 22.9 kPa, but the hypercapnia and acidosis continued. Stepwise reduction of the mean airway pressure (26 cm H(2)O), and oscillating frequencies (3.5 Hz), as well as increasing the oscillating amplitudes (95 cm H(2)O) resulted in an unchanged Pa(co(2)), but oxygenation worsened. The new pumpless extracorporeal interventional lung assist device (ILA, NovaLung, Hechingen, Germany) was therefore used for carbon dioxide elimination to enable a less aggressive ventilation strategy. Pa(co(2)) normalized after initiation of ILA. HFOV with a mean airway pressure of 32 cm H(2)O was maintained, but with a higher oscillatory frequency (9 Hz) and very low oscillatory amplitude (25 cm H(2)O). After 6 days, the patient was transferred to a conventional ventilator, and ILA was discontinued after 13 days without complications.

Gastric insufflation pressure, air leakage and respiratory mechanics in the use of the laryngeal mask airway (LMA) in children

BACKGROUND

The objective of the present study was to evaluate the prelaryngeal position of the laryngeal mask airway (LMA(TM)) in children, and to determine the influence of mask positioning on gastric insufflation and oropharyngeal air leakage.

METHODS

A total of 100 children, 3-11 years old, scheduled for surgical procedures in the supine position under general anaesthesia were studied. After clinically satisfactory LMA placement, tidal volumes were increased stepwise until air entered the stomach, airway pressure exceeded 30 cmH(2)O, or air leakage from the mask seal prevented further increases in tidal volume. LMA position in relation to the laryngeal entrance was verified using a flexible bronchoscope.

RESULTS

The insertion of the LMA with a clinically satisfactory position was achieved in all patients at the first attempt. Gastric air insufflation occurred in five of 49 patients with malpositioned LMA. No incident of gastric air insufflation was observed in 51 patients with correctly positioned LMA. The minimum inspiratory pressure leading to mask leakage was 17 cmH(2)O for incorrectly positioned LMA, and 25 cmH(2)O for correctly positioned LMA. Clinically unrecognized LMA malposition was associated with a significantly increased incidence of either oropharyngeal leakage (r = 0.59; P = 0.0001) or gastric insufflation (r = 0.25; P = 0.01).

CONCLUSIONS

Clinically undetected LMA malpositioning is a significant risk factor for gastric air insufflation in children between 3 and 11 years, undergoing positive pressure ventilation, especially at inspiratory airway pressures above 17 cmH(2)O.

Temporal dynamics of lung aeration determined by dynamic CT in a porcine model of ARDS

We used dynamic CT to identify two different time constants of lung aeration and their individual contribution to the total increase in cross-sectional lung area in healthy and experimentally damaged lungs. In five healthy pigs, inflation and deflation between 0 and 50 cm H2O was imposed during dynamic (250 ms/image) CT acquisition, and repeated after experimental lung injury by saline lavage. The fractional areas of density ranges, which represent aerated lung parenchyma, were determined planimetrically, and their time for expansion during the manoeuvre was fitted using a bi-exponential model. Thus, two compartments, their sizes, i.e. their relative contributions to lung area aerated by the manoeuvre, and their specific time constants (tau) were sought. Healthy lungs were characterized best by a one-compartmental behaviour with one tau only, both during inflation (median tau=0.5 s; range 0.4-0.6 s) and deflation (1.2 s; 1.1-1.3 s). In damaged lungs two compartments were found both during inspiration and expiration, with 86% (78-87%) of the recruitable lung area following a short tau of 0.5 s (0.5-0.6), and 14% (13-22%) following a longer tau of 9.1 s (8-16.8 s) during inflation. During expiration, damaged lungs had a short tau of 0.8 s (0.5-1.0 s) for 94% (84-100%) of deflated lung area, and a longer tau of 26.5 s (7.1-34.3 s) for 6% (0-16%). We conclude that dynamic CT indicates the relative size and temporal behaviour of functional compartments in normal and abnormal lungs. Our findings suggest that after lung damage, cyclic ventilation with inspiratory periods of <10 s duration will not achieve maximum recruitment for a chosen inspiratory pressure. In ARDS, the short expiratory tau predisposes to atelectasis formation if expiratory times are >1 s.

Intention tremor, parkinsonism, and generalized brain atrophy in male carriers of fragile X

The authors report five elderly men with the fragile X premutation who had a progressive action tremor associated with executive function deficits and generalized brain atrophy. These individuals had elevated fragile X mental retardation 1 gene (FMR1) messenger RNA and normal or borderline levels of FMR1 protein. The authors propose that elevations of FMR1 messenger RNA may be causative for a neurodegenerative syndrome in a subgroup of elderly men with the FMR1 premutation.

Component analysis of verbal fluency in patients with schizophrenia

OBJECTIVE

Clustering and-switching components of phonemic fluency performance were compared in patients with schizophrenia and healthy normal controls.

BACKGROUND

These components were selected to provide evidence for a specific anatomic locus for the breakdown of language processes or for a multiple-disease model of schizophrenia.

METHOD

As part of a larger battery of neuropsychological tests, phonemic fluency tests were administered on an individual basis. On separate 60-second trials, participants were instructed to generate words beginning with the letters C, F, and L, excluding proper names and variants of the same word. Three scores were obtained for each participant: (1) number of words generated, excluding errors and repetitions; (2) mean cluster size; and (3) raw number of switches.

RESULTS

The patients showed small but significant impairments in clustering and larger impairments in switching relative to normal controls.

CONCLUSIONS

This pattern suggests a relatively greater deficit in functioning in the frontal lobe than in the temporal lobe. However, neither measure was able to completely discriminate patients with schizophrenia from controls. Moreover, differences in fluency performance were observed among subtypes of schizophrenia. Taken together, the findings of impaired performance for both aspects of fluency, differences between subtypes, and the failure to completely discriminate patients with schizophrenia from controls indicate that there is not a single marker of the disease, at least among these fluency variables. Instead, the current findings are more supportive of a multiple-disease model of schizophrenia.

Successful treatment of a patient with ARDS after pneumonectomy using high-frequency oscillatory ventilation

High frequency oscillatory ventilation (HFOV) was used in a patient who developed the acute respiratory distress syndrome 5 days following a right pneumonectomy for bronchogenic carcinoma. When conventional pressure-controlled ventilation failed to maintain adequate oxygenation, HFOV dramatically improved oxygenation within the first few hours of therapy. Pulmonary function and gas exchange recovered during a 10-day period of HFOV. No negative side effects were observed. Early use of HFOV may be a beneficial ventilation strategy for adults with acute pulmonary failure, even in the postoperative period after lung resection.

Computed tomography-based tracheobronchial image reconstruction allows selection of the individually appropriate double-lumen tube size

OBJECTIVES

To determine whether individualized selection of double-lumen tubes or alternatives based on three-dimensional reconstruction of the tracheobronchial image from routine preoperative computed tomography (CT) scans leads to clinically appropriate choices.

DESIGN

Prospective observational study; comparison to historic controls.

SETTING

Anesthesia and radiology facilities of a university medical center.

PARTICIPANTS

Forty-nine patients undergoing thoracic surgery requiring one-lung ventilation.

INTERVENTIONS

Three-dimensional image reconstruction of individual tracheobronchial anatomy was performed from routine preoperative spiral CT scans as well as from scans of five left-sided and four right-sided double-lumen tubes. Results of image-based tube size selection were compared with literature recommendations. Prospectively, individualized tube selection was performed by superimposition of printed transparencies of tubes over the tracheobronchial system and was validated using bronchoscopic and clinical criteria (n = 24).

MEASUREMENTS AND MAIN RESULTS

Three-dimensional reconstruction visualized individual anatomy with good accuracy and resolution. Correlations between patient morphology and tracheobronchial dimensions were weak (height versus mainstem bronchial diameters: r < 0.50). In 11 of 48 patients (23%). CT-fitted double-lumen tube sizes would have differed from a conventional height-based and gender-based selection. Individual, prospective, CT-based double-lumen tube selection was associated with (1) good fit and positioning confirmed by fiberoptic bronchoscopy, (2) adequate bronchial cuff seal volumes, (3) complete lung separation, and (4) oxygenation and ventilation parameters during one-lung ventilation similar to those with conventional size selection. In one patient, three-dimensional CT study allowed noninvasive evaluation of a tracheal stenosis precluding double-lumen tube placement.

CONCLUSION

Individualized selection of double-lumen tube size using CT-based reconstructions of tracheobronchial anatomy leads to clinically appropriate choices. Risks resulting from variations in tracheobronchial morphology are recognized in advance.

[Multi-rotation CT during continuous ventilation: comparison of different density areas in healthy lungs and in the ARDS lavage model]

PURPOSE

In this animal study, density ranges for CT-based quantification of ventilated lung area were determined. Healthy lungs and ARDS lungs were compared during artificial respiration.

MATERIAL AND METHODS

CT-scans were performed in 5 anesthetized pigs using a dynamic multiscan CT option on a predefined transverse slice (slice thickness 1 mm; effective temporal resolution, 250 ms). During continuous CT acquisition, airway pressure was increased or decreased in a stepwise manner. In all images, areas of defined HU ranges were determined planimetrically. The lower threshold was set to -910 HE in all images. The upper threshold was varied from -800 HE to -200 HE in steps of 100 HE.

RESULTS

During inspiration in healthy lungs the HU-range of -910 to -700 HU showed the largest increase in area. During inspiration in ARDS lungs the HU range from -910 to -300 HU allowed the most sensitive assessment of area changes. These findings can be explained by recruitment of atelectases (HU-range > -300 HU) and their transition to a HU range from -700 to -300 HU.

CONCLUSION

Dynamic multiscan CT acquisitions are a useful method to determine changes of ventilated lung area during a respiratory cycle. Different HU-ranges are required to access volume changes in healthy lungs and in ARDS lungs.

Adaptive lung ventilation (ALV) during anesthesia for pulmonary surgery: automatic response to transitions to and from one-lung ventilation

Adaptive lung ventilation is a novel closed-loop-controlled ventilation system. Based upon instantaneous breath-to-breath analyses, the ALV controller adjusts ventilation patterns automatically to momentary respiratory mechanics. Its goal is to provide a preset alveolar ventilation (V'A) and, at the same time, minimize the work of breathing. Aims of our study were (1) to investigate changes in respiratory mechanics during transition to and from one-lung ventilation (OLV), (2) to describe the automated adaptation of the ventilatory pattern.

METHODS

With institutional approval and informed consent, 9 patients (33-72 y, 66-88 kg) underwent ALV during total intravenous anesthesia for pulmonary surgery. The ALV controller uses a pressure controlled ventilation mode. V'A is preset by the anesthesiologist. Flow, pressure, and CO2 are continuously measured at the DLT connector. The signals were read into a IBM compatible PC and processed using a linear one-compartment model of the lung to calculate breath-by-breath resistance (R), compliance (C), respiratory time constant (TC), serial dead space (VdS) and V'A. Based upon the results, the controller optimizes respiratory rate (RR) and tidal volume (VT) such as to achieve the preset V'A with the minimum work of breathing. In addition to V'A, only PEEP and FIO2 settings are at the anesthesiologist's discretion. All patients were ventilated using FIO2 = 1,0 and PEEP = 3 cm H2O. Parameters of respiratory mechanics, ventilation, and ABG were recorded during three 5-min periods: 10 min prior to OLV (1), 20 min after onset of OLV (II), and after chest closure (III). Data analyses used nonparametric comparisons of paired samples (Wilcoxon, Friedman) with Bonferroni's correction. Significance was assumed at p < 0.05. Values are given as medians (range).

RESULTS

20 min after onset of OLV (II), resistance had approximately doubled compared with (1), compliance had decreased from 54 (36-81) to 50 (25-70) ml/cm H2O. TC remained stable at 1.4 (0.8-2.4) vs. 1.2 (0.9)-1.6) s. Institution of OLV was followed by a reproducible response of the ALV controller. The sudden changes in respiratory mechanics caused a transient reduction in VT by 42 (8-59)%, with RR unaffected. In order to reestablish the preset V'A, the controller increased inspiratory pressure in a stepwise fashion from 18 (14-23) to 27 (19-39) cm H2O, thereby increasing VT close to baseline (7.5 (6.6-9.0) ml/kg BW vs. 7.9 (5.4-11.7) ml/kg BW). The controller was, thus, effective in maintaining V'A. The minimum PaO2 during phase II was 101 mmHg. After chest closure, respiratory mechanics had returned to baseline.

CONCLUSIONS

Respiratory mechanics during transition to and from OLV are characterized by marked changes in R and C into opposite directions, leaving TC unaffected. The ALV controller manages these transitions successfully, and maintains V'A reliably without intervention by the anesthesiologist. VT during OLV was found to be consistently lower than recommended in the literature.

Laryngeal mask airway position and the risk of gastric insufflation

A potential risk of the laryngeal mask airway (LMA) is an incomplete mask seal causing gastric insufflation or oropharyngeal air leakage. The objective of the present study was to assess the incidence of LMA malpositions by fiberoptic laryngoscopy, and to determine their influence on gastric insufflation and oropharyngeal air leakage. One hundred eight patients were studied after the induction of anesthesia, before any surgical manipulations. After clinically satisfactory LMA placement, tidal volumes were increased stepwise until air entered the stomach, airway pressure exceeded 40 cm H2O, or air leakage from the mask seal prevented further increases in tidal volume. LMA position in relation to the laryngeal entrance was verified using a flexible bronchoscope. The overall incidence of LMA malpositions was 40% (43 of 108). Gastric air insufflation occurred in 19% (21 of 108), and in 90% (19 of 21) of these patients, the LMA was malpositioned. Oropharyngeal air leakage occurred in 42%, and was independent of LMA position. We conclude that clinically unrecognized LMA malposition is a significant risk factor for gastric air insufflation.

IMPLICATIONS

Routine placement of laryngeal mask airways does not require laryngoscopy. In our study, fiberoptic verification of mask position revealed suboptimal placement in 40% of cases. Such malpositioning considerably increased the risk of gastric air insufflation.

[Automated anesthesia record systems]

The introduction of electronic anaesthesia documentation systems was attempted as early as in 1979, although their efficient application has become reality only in the past few years. The advantages of the electronic protocol are apparent: Continuous high quality documentation, comparability of data due to the availability of a data bank, reduction in the workload of the anaesthetist and availability of additional data. Disadvantages of the electronic protocol have also been discussed in the literature. By going through the process of entering data on the course of the anaesthetic procedure on the protocol sheet, the information is mentally absorbed and evaluated by the anaesthetist. This information may, however, be lost when the data are recorded fully automatically-without active involvement on the part of the anaesthetist. Recent publications state that by using intelligent alarms and/or integrated displays manual record keeping is no longer necessary for anaesthesia vigilance. The technical design of automated anaesthesia records depends on an integration of network technology into the hospital. It will be appropriate to connect the systems to the internet, but safety requirements have to be followed strictly. Concerning the database, client server architecture as well as language standards like SQL should be used. Object oriented databases will be available in the near future. Another future goal of automated anaesthesia record systems will be using knowledge based technologies within these systems. Drug interactions, disease related anaesthetic techniques and other information sources can be integrated. At this time, almost none of the commercially available systems has matured to a point where their purchase can be recommended without reservation. There is still a lack of standards for the subsequent exchange of data and a solution to a number of ergonomic problems still remains to be found. Nevertheless, electronic anaesthesia protocols will be required in the near future. The advantages of accurate documentation and quality control in the presence of careful planning outweight cost considerations by far.

Respiratory mechanics, gastric insufflation pressure, and air leakage of the laryngeal mask airway

A potential risk of the laryngeal mask airway (LMA) is incomplete mask seal, which causes air leakage or insufflation of air into the stomach. The objective of the present study was to assess respiratory mechanics, quantify air leakage, and measure gastric air insufflation in patients ventilated via the LMA. Thirty patients were studied after induction of anesthesia but prior to any surgical manipulations. After the insertion of the LMA, patients were ventilated with increasing tidal volumes until one of the three following end points were reached: 1) gastric air insufflation, 2) airway pressure > 40 cm H2O, or 3) limitation of further increase in tidal volume by air leakage. The following variables were determined:inspired volume (VI), expired volume (VE), maximum inspiratory pressure (Pmax), airway pressure at gastric inflation (Pinfl), respiratory time constant (RC), compliance (C), resistance (R), and leakage fraction (FL). Respiratory mechanics were in the physiological range. Gastric insufflation occurred in 27% of the patients at inspiratory pressures between 19 and 33 cm H2O. Air leakage of more than 10% was evident at inspiratory pressures between 25 and 34 cm H2O. The end point of 40 cm H2O airway pressure was reached in only three patients. We conclude that the LMA is not better in preventing airway pressure transmission to the esophagus than a conventional face mask. However, a high FL is associated with reduced gastric air insufflation.

[The effect of preischemic blood sugar concentration on hemodynamics and regional organ blood flow during and following cardiopulmonary resuscitation (CPR) in swine]

Blood glucose alterations prior to cerebral ischaemia are associated with poor neurologic outcome, possibly due to extensive lactic acidosis or energy failure. Cerebral effects of hyper- or hypoglycaemia during cardiopulmonary resuscitation (CPR) are less well known. In addition, little information is available concerning cardiac effects of blood glucose alterations. The aim of this study was to evaluate the effects of pre-cardiac-arrest hypo- or hyper-glycaemia compared to normoglycaemia upon haemodynamics, cerebral blood flow (CBF) and metabolism (CMRO2), and regional cardiac blood flow during CPR subsequent to 3 min of cardiac and respiratory arrest and after restoration of spontaneous circulation.

METHODS

After approval by the State Animal Investigation Committee, 29 mechanically ventilated, anaesthetised pigs were instrumented for haemodynamic monitoring and blood flow determination by the radiolabeled microsphere technique. The animals were randomly assigned to one of three groups: in group 1 (n = 9) blood glucose was not manipulated; in group II (n = 10) blood glucose was increased by slow infusion of 40% glucose to 319 +/- 13 mg/dl; in group III (n = 10) blood glucose was lowered by careful titration with insulin to 34 +/- 2 mg/dl. After 3 min of untreated ventricular fibrillation and respiratory arrest, CPR (chest compressor/ventilator (Thumper) and epinephrine infusion) was commenced and continued for 8 min. Thereafter, defibrillation was attempted, and if successful, the animals were observed for another 240 min. Cerebral perfusion pressure (CPP), CBF, CMRO2, coronary perfusion pressure (CorPP), and regional cardiac blood flow were determined at control, after 3 min of CPR, and at 10.30, and 240 min post-CPR.

RESULTS

In group 1. 4/9 animals (44%) could be successfully resuscitated; in group II 4/10 (40%); and in group III 0/10 (0%). Prior to cardiac arrest, mean arterial pressure, CPP, and CorPP in group III were significantly lower compared to groups I and II. In group I. CPP during CPR was 26 +/- 6 mmHg; CBF 31 +/- 9 ml/ min/100g CMRO2 3.8 +/- 1.2 ml/ min/100 g; CorPP 18 +/- 5 mmHg; and left ventricular (LV) flow 35 +/- 15 ml/min/100 g. In group II; CPP = 21 +/- 5; CBF 21 +/- 7; CMRO2 1.8 +/- 0.8; CorPP 16 +/- 6; and LV flow 22 +/- 9; and in group III: CPP 15 +/- 3; CBF 11 +/- 8; CMRO2 1.5 +/- 1.1; CorPP 4 +/- 2; and LV flow 19 +/- 10. During the 240-min post-resuscitation period, there were no differences in CBF, CMRO2, or LV flow between groups I and II.

CONCLUSION

Hypoglycaemia prior to cardiac arrest appears to be predictive for a poor cardiac outcome, whereas hyperglycaemia does not impair resuscitability compared to normoglycaemia. In addition, hyperglycaemia did not affect LV flow, CBF, or CMRO2. However, it has to be kept in mind that haemodynamics and organ blood flow do not permit conclusions with respect to functional neurologic recovery or histopathologic damage to the brain, which is very likely to be associated with hyperglycaemia.

[Adaptive lung ventilation (AVL). Evaluation of new closed loop regulated respiration algorithm for operation in the hyperextended lateral position]

The lateral decubitus position is the standard position for nephrectomies. There is a lack of data about the effects of this extreme position upon respiratory mechanics and gas exchange. In 20 patients undergoing surgery in the nephrectomy position, we compared a new closed-loop-controlled ventilation algorithm, adaptive lung ventilation (ALV), which adapts the breathing pattern automatically, to the respiratory mechanics with conventionally controlled mandatory ventilation (CMV). The aims of our study were (1) to describe positioning effects on respiratory mechanics and gas exchange, (2) to compare ventilatory parameters selected by the ALV controller with traditional settings of CMV, and (3) to assess the individual adaptation of the ventilatory parameters by the ALV controller. The respirator used was a modified Amadeus ventilator, which is controlled by an external computer and possesses an integrated lung function analyzer. In a first set of measurements, we compared parameters of respiratory mechanics and gas exchange in the horizontal supine position and 20 min after changing to the nephrectomy position. In a second set of measurements, patients were ventilated with ALV and CMV using a randomized crossover design. The CMV settings were a tidal volume of 10 ml/kg body weight, a respiratory rate of 10 breaths/min, an I:E ratio of 1:1.5, and an end-inspiratory pause of 30% of inspiratory time. With both ventilation modes F1O2 was set to 0.5 and PEEP to 3 cm H2O. During ALV a desired alveolar ventilation of 70 ml/ kg KG.min was preset. All other ventilatory parameters were determined by the ALV controller according to the instantaneously measured respiratory parameters. Positioning induced a reduction of compliance from 61.6 to 47.9 ml/cm H2O; the respiratory time constant shortened from 1.2 to 1.08 s, whereas physiological dead space increased from 158.9 to 207.5 ml. On average, the ventilatory parameters selected by the ALV controller resembled very closely those used with CMV. However, an adaptation to individual respiratory mechanics was clearly evident with ALV. In conclusion, we found that the effects of positioning for nephrectomy are minor and may give rise to problems only in patients with restrictive lung disease. The novel ALV controller automatically selects ventilatory parameters that are clinically sound and are better adapted to the respiratory mechanics of ventilated patients than the standardized settings of CMV are.

[Anesthesia in endovascular treatment of aortic aneurysm. Results and perioperative risks]

Surgical treatment of aortic aneurysms carries significant cardiovascular risks. Transvascular insertion of endoluminal prostheses is a new, minimally invasive treatment for aortic aneurysms. The pathophysiology of this novel procedure, risks and benefits of different anaesthetic techniques, and typical complications need to be defined.

METHODS

With their informed, written consent, 19 male patients aged 48-83 years of ASA physical status III and IV with infrarenal (n = 18) or thoracic (n = 1) aortic aneurysms underwent 23 stenting procedures under general endotracheal (n = 9), epidural (n = 8), or local anaesthesia with sedation (n = 6). Intra-anaesthetic haemodynamics, indicators of postoperative (p.o.) oxygenation and systemic inflammatory response, and perioperative complications were analysed retrospectively and compared between anaesthetic regimens.

RESULTS

Groups were well matched with regard to morphometry and preoperative risk profiles (Table I). The use of pulmonary artery pressure monitoring, incidence of intraoperative hypotensive episodes, and p.o. intensive care was more frequent with general anaesthesia. Groups did not differ in total duration of anaesthesia care, incidence and duration of intraoperative hypertensive, brady-, or tachycardic periods, incidence of arterial oxygen desaturation, use of vasopressors, colloid volume replacements, or antihypertensives (Table 2). Postoperatively, all groups showed a similar, significant systemic inflammatory response, i.e., rapidly spiking temperature (p.o. evening: mean peak 38.5 +/- 1.0 degrees C). leucocytosis, and rise of acute-phase proteins without bacteraernia (Table 3). During this period, despite supplemental oxygen, pulse oximetry revealed temporary arterial desaturation in 13 of 18 patients (70%) (Table 3). In 3 patients, hyperpyrexia was associated with intermittent tachyarrhythmias (n = 3) and angina pectoris (n = 1). There was no conversion to open aortic surgery, perioperative myocardial infarction, or death.

CONCLUSIONS

Regional and local anaesthesia with sedation are feasible alternatives to general endotracheal anaesthesia for minimally invasive treatment of aortic aneurysms by endovascular stenting. However, invasive monitoring and close postoperative monitoring are strongly recommended with either method. Specific perioperative risks in patients with limited cardiovascular or pulmonary reserve are introduced by the abacterial systemic inflammatory response to aortic stent implantation. Hyperpyrexia increases myocardial and whole-body oxygen consumption, and can precipitate tachyarrhythmias. Hyperfibrino-genaemia may increase the risk of postoperative arterial and venous thromboses. Close monitoring of vital parameters and prophylactic measures, including oxygen supplementation, low-dose anticoagulation, antipyretics, and fluid replacement are warranted until this syndrome resolves.

[Continuous breath alcohol analysis. Monitoring of irrigation absorption syndrome in transurethral prostate resection]

The absorption of large volumes of irrigation fluid is a major problem in transurethral prostatic surgery (TUR-P). Various indicators have been tested to monitor fluid absorption with regard to continuous registration and sufficient accuracy. The volumetric fluid balance is not suitable as a routine method because of its inaccuracy. Easily accessible parameters are unspecific because of surgical bleeding (haematocrit [Hct]), or are interfered with by physiological counter-regulatory actions (serum sodium [Na] concentration). In 1986 Hulten et al. suggested adding 2% ethanol to the irrigation fluid as a marker and investigated it intermittently in the expired air with an alcohol-test appliance. In a prospective clinical study of 17 patients undergoing TUR-P under spinal anaesthesia, expiratory concentrations of alcohol that was added to the irrigation fluid (2% ethanol in Purisole, Fresenius, Bad Homburg) were monitored. Gas was continuously sampled from the nasopharynx through a nasal cannula and the ethanol concentration was measured using a modified diverting anaesthetic gas monitor (Normac, Datex, Helsinki) that allows continuous as well as early detection of the absorbed irrigation fluid with reliable accuracy for clinical use. In addition, at intervals of 10 minutes we measured blood alcohol, end-tidal alcohol (Alcotest 7110, Dräger, Lübeck), haematocrit, serum Na concentration, and blood gases. Sixty-eight measurements were obtained from the 17 patients. As shown in other studies, serum Na (r2 = 0.68) and Hct (r2 = 0.39) correlated poorly with the irrigation fluid as determined by serum alcohol levels. In contrast, the expiratory alcohol measurements with the Alcotest 7110 (r2 = 0.93) and Normac devices (r2 = 0.85) were closely related. Continuous monitoring of the expiratory alcohol concentration with a Normac monitor closely reflects blood alcohol concentration, and may hence serve as a useful semiquantitative monitor of irrigation fluid absorption during TUR-P.

Assessment of pulmonary mechanics and gastric inflation pressure during mask ventilation

INTRODUCTION

Mask ventilation is a procedure routinely used in emergency medicine. Potential hazards are inadequate alveolar ventilation and inflation of the stomach with air, leading to subsequent regurgitation and aspiration. The aim of this study was to measure lung function and gastric inflation pressures during mask ventilation.

METHODS

For this purpose, 31 patients scheduled for routine urological procedures were studied during induction of anesthesia. Lung function was assessed by recording respiratory flow and pressure directly at the face mask. Gastric inflation was observed with a microphone taped to the epigastric area.

RESULTS

Gastric inflation occurred in 22 of the 31 patients. Mean gastric inflation pressure was 27.5 +/- 6.55 cm H2O, mean compliance was 67 +/- 24.1 ml/cm H2O, mean resistance was 17.4 +/- 6.41 cm H2O/L/sec, and the mean respiratory time constant was 1.1 +/- 0.26 seconds.

CONCLUSIONS

These data suggest that inspiratory pressure be limited to 20 cm H2O, and that an inspiratory time of at least four times the respiratory time constant be allowed. Monitoring airway pressure and gastric inflation is a simple technique that may improve the safe-ty of patients during mask ventilation.

Automated anaesthesia record systems, observations on future trends of development

The introduction of electronic anaesthesia documentation systems was attempted as early as in 1979, although their efficient application has become reality only in the past few years. Today, documentation technology is offered by most of the monitor manufacturers and new systems are being developed by various working groups. The advantages of the electronic protocol are apparent: Continuous high quality documentation, comparability of data due to the availability of a anaesthesia data bank, reduction of the workload of the anaesthesia staff and availability of new additional information. Disadvantages of the electronic protocol have also been discussed. Typically, by going through the process of entering data on the course of the anaesthetic procedure on the protocol sheet, the information is mentally absorbed and evaluated by the anaesthetist. This mental processing of information may, however, be missing when the data are recorded fully automatically--without active involvement on the part of the anaesthetist. It seems that electronic anaesthesia protocols will be required in the near future. The advantages of accurate documentation and quality control in the presence of careful planning will outweight cost considerations. However, at this time, almost none of the commercially available systems have matured to a point where their purchase can be recommended without reservation. There is still a lack of standards for the subsequent exchange of data and a solution to a number of ergonomic problems still remains to be found.

The AVL-mode: a safe closed loop algorithm for ventilation during total intravenous anesthesia

The Adaptive Lung Ventilation Controller (ALV-Controller) represents a new approach to closed loop control of ventilation. It is based on a pressure controlled ventilation mode. Adaptive lung ventilation signifies automatic breath by breath adaptation of breathing patterns to the lung mechanics of an individual patient. The specific goals are to minimize work of breathing, to maintain a preset alveolar ventilation and to prevent the occurrence of intrinsic PEEP. We ventilated 5 patients undergoing major abdominal procedures using ALV. ALV was tolerated well in all patients. Alveolar ventilation was preset between 5500 and 6500 ml/min. Serial dead space (Vds) and respiratory time constant (resistance * compliance) of the patients ranged from 104 to 164 ml and 0.74 to 1.5 s, respectively. The resulting respiratory rates ranged from 8 to 15 breaths/min, the tidal volumes from 542 to 829 ml, and the applied maximum inspiratory pressures from 15.5 to 18.9 mbar. Expiratory time was sufficient in all cases to allow complete expiration and to avoid intrinsic PEEP. I: E-relations ranged from 0.36 to 0.76. After a step change in alveolar ventilation rise times of the breathing patterns were recorded at values from 7 to 67 s. Overshoot did not reach statistic significance compared to the variations in breathing patterns which occurred during stable measuring periods. Accuracy of the controller was high (27.8 ml difference between preset and applied alveolar ventilation in the mean) and stability was sufficient for clinical purposes. The results of this preliminary study show that the breathing patterns selected by the controller were well adapted to the lung mechanics of the patients. Respiratory rates, inspiratory pressures and tidal volumes were within the clinically acceptable range in all patients.

An adaptive lung ventilation controller

Closed loop control of ventilation is traditionally based on end-tidal or mean expired CO2. The controlled variables are the respiratory rate RR and the tidal volume VT. Neither patient size or lung mechanics were considered in previous approaches. Also the modes were not suitable for spontaneously breathing subjects. This report presents a new approach to closed loop controlled ventilation, called Adaptive Lung Ventilation (ALV). ALV is based on a pressure controlled ventilation mode suitable for paralyzed, as well as spontaneously breathing, subjects. The clinician enters a desired gross alveolar ventilation (V'gA in l/min), and the ALV controller tries to achieve this goal by automatic adjustment of mechanical rate and inspiratory pressure level. The adjustments are based on measurements of the patient's lung mechanics and series dead space. The ALV controller was tested on a physical lung model with adjustable mechanical properties. Three different lung pathologies were simulated on the lung model to test the controller for rise time (T90), overshoot (Ym), and steady state performance (delta max). The pathologies corresponded to restrictive lung disease (similar to ARDS), a "normal" lung, and obstructive lung disease (such as asthma). Furthermore, feasibility tests were done in 6 patients undergoing surgical procedures in total intravenous anesthesia. In the model studies, the controller responded to step changes between 48 seconds and 81 seconds. It did exhibit an overshoot between 5.5% and 7.9% of the setpoint after the step change.(ABSTRACT TRUNCATED AT 250 WORDS)

[Modern forms of artificial respiration]

Mechanical ventilation has become a widely used technique in anaesthesiology and intensive care medicine. Difficulties arise with patients who suffer from acute or chronic pulmonary disease. Lung models are used to simulate the behaviour of healthy and diseased lungs and to optimize breathing patterns. Flow-controlled ventilation is suitable for healthy lungs. Diseased lungs need more finely differentiated ventilatory modes that adapt to the different time constants within the lung. PCV seems to have some advantages in ventilation of such lungs. It has been demonstrated that prolongation of inspiratory time and inversion of the I:E ratio can open nonventilated compartments of the lung and thus reduce intrapulmonary shunt. BiPAP ventilation and APRV serve the same purpose. Additionally, they support spontaneous breathing of the patient. Weaning from the respirator can be achieved by either reducing the number of mandatory breaths (IMV, SIMV, MMV) or reducing the work of breathing by applying inspiratory pressure support (PSV). Both techniques can be applied simultaneously. BiPAP ventilation and APRV are also suitable for weaning patients from a ventilator. Respirators able to adapt breathing patterns to the lung mechanics of a patient automatically on the basis of a breath-to-breath lung function analysis (ALV) are currently in clinical development.

[Modification of oxygen consumption following major abdominal surgery by epidural anesthesia]

In the postoperative period patients are at risk of excessive oxygen consumption (VO2). However, patients suffering from cardiovascular disease may be unable to increase their oxygen transport capacity sufficiently and may be especially vulnerable to tissue hypoxia as part of the reaction to intraoperative stress. During the last 10 years conflicting results concerning the benefits of a combined epidural and light general anaesthesia have been published. Some of the results indicate that postoperative catabolism may be depressed and that the neuroendocrine response to stress may be inhibited by such a combined technique. We studied the effect of a combined epidural and light general anaesthesia on VO2 in the early post-operative period. PATIENTS AND METHODS. Three groups of patients were studied: group 1 contained 10 patients scheduled for major urological procedures of at least 3 h duration who received a combined epidural and light general anaesthesia. Group 2 contained 17 patients with procedures comparable to group 1 but received a standard general anaesthesia with isoflurane, N2O and fentanyl. In addition, 13 patients undergoing minor urological procedures of less than 2 h duration and undergoing standard general anaesthesia were included in the study as a control group (group 3). All patients gave informed consent. Preoperative management was the same in the three groups. Perioperative risk was assessed according to the ASA classification. In group 1 patients, an epidural catheter was placed preoperatively at the L3/4 interspace and tested for correct positioning using 4 ml of 2% mepivacaine with epinephrine 1:200,000. After induction of anaesthesia an epidural block was established with 0.5% bupivacaine for intraoperative analgesia and 0.25% bupivacaine for postoperative pain relief. The initial dosage was determined (according to Bromage's method) to reach a sensory level of T-6. Two-thirds of the initial dose was the given on two occasions, each 90 min after the dose before. End-tidal isoflurane concentrations ranged between 0.3 and 0.6 vol% in this group. In groups 2 and 3, endtidal isoflurane concentrations of 1.0 to 1.5 vol% were applied. Postoperative analgesia was achieved in these groups using repeated doses of 7.5 mg piritramide i.v. Oxygen consumption was measured in the recovery room using the Deltatrac (Datex) metabolic monitor. Measurements were performed with a canopy room air dilution technique. Arterial oxygen saturation of the patients was monitored continuously using pulse oximetry. Data acquisition was started within 10 min after extubation and continued for at least 60 min until a steady state of oxygen consumption was reached. We recorded the average VO2 during the initial 5 min of the measurement period and during another 5-min period after the steady state was reached (45-60 min after extubation). RESULTS. Patients in the three groups were comparable in age, height and body weight (Table 1). The duration of procedures in groups 1 and 2 ranged between 4 and 7 h. Groups 1 and 2 were further comparable in terms of intraabdominal procedures, intraoperative blood loss, fluid replacement, and fall in body temperature during the operation (Table 2). Heart range was significantly higher in group 2 during the 5-min test interval (Table 3). Figure 1 shows the typical course of oxygen consumption in patients of groups 1, 2, and 3. The readings in the group 1 patient as well as in the group 3 patients were stable throughout the observation period. Oxygen consumption was in the physiological range. In contrast, in the group 2 patients during the early postoperative period, increased values of VO2 (approx. 50% above normal) were observed. These findings were highly significant in our study. In the early postoperative period (5 min) patients in group 1 showed a VO2 or 3.6 +/- 0.4 ml.kg-1.min-1. This was the same as in group 3 (3.5 +/- 0.3 ml.kg-1.min-1). In contrast, in group 2 a VO2 of 5.3 +/- 0.7 ml.kg-1.min-1

[Extracorporeal shock-wave therapy (ESWT) for pseudoarthrosis. A new indication for regional anesthesia]

Extracorporeal shock-wave therapy for the treatment of pseudarthrosis is a new indication for anaesthesia. In a clinical trial of 65 treatments in 53 patients, the anaesthetic procedure is shown. Regional anaesthesia, mainly plexus blocks of the upper and lower extremities, was performed in nearly all cases. The various localisations of the pseudarthroses and the types of anaesthetic techniques used are shown in Table 1. In all, we performed 9 epidural blocks, 2 spinal blocks, 29 axillary blocks, 3 supraclavicular perivascular blocks (Winnie), 1 psoas compartment block, and 20 sciatic/femoral 3-in-1 blocks. The shock waves used for this therapy are several times stronger than those used for nephrolithotripsy. Furthermore, the shockwaves are focused on bone and periosteum, which is abundantly innervated. Therefore, in contrast to nephro-lithotripsy with second-generation lithotripters, anaesthesia must be performed for this therapy. We chose regional anaesthesia for several reasons: the procedures are located in the arms or legs, which can readily be anaesthetised by regional blocks. The duration of treatment ranged up to several hours. By using regional anaesthesia, we were able to avoid unnecessary exposure to general anaesthetics. Finally, most of the patients wanted to stay awake during the new treatment and therefore opted for regional techniques. A typical set-up for the treatment is shown in Fig 1. In 67% of the patients fracture healing was significantly improved by the new therapy. Acceptance of therapy and anaesthesia by the patients was very good.

The measurement of enzyme activities in the resting human polymorphonuclear leukocyte--critical estimate of a method

As a system for study, the isolated human polymorphonuclear leukocyte combines the advantages of a quasi-non-invasive preparation with a nearly complete complement of enzymes of carbohydrate and energy metabolism. However, small sample volumes and, in some cases, very low enzyme activities make high demands on sample processing, storage, and performance of continuous measurements, if the enzyme activities are to be measured with acceptable reproducibility. In the presented study several aspects of homogenization, storage, and continuous measurement were scrutinized, to identify critical steps and consider ways of optimizing the method. Polymorphonuclear leukocytes were separated from the blood of healthy subjects by sedimentation and density gradient centrifugation. After ultrasonic homogenization, 13 enzymes of glycolysis and gluconeogenesis, the tricarboxylic acid cycle, and glycogen metabolism were determined photometrically. The variation of several conditions showed: 1. The duration of exposure to ultrasound for the homogenization of polymorphonuclear leukocytes has no influence over a wide range of time. 2. Addition of the detergents Triton X-100 and deoxycholic acid, as well as the SH-group protector dithiothreitol, to the homogenizing medium increased the measured activities of only a few enzymes. 3. Considerable inaccuracy was encountered when the suspension was divided into parts for homogenization with different additives; such splitting of the suspension should therefore be performed only when necessary, as in the determination of reference values (e.g. protein or DNA content of the cell suspension). 4. Twenty four-fold determination of enzyme activities from one homogenate resulted in precisions between 4.5% (citrate synthase) and 14.4% (transketolase), which is satisfactory for the low activities (as low as 1 U/l) in the homogenate. 5. The reproducibility of enzyme activities, measured in homogenates of polymorphonuclear leukocytes from different blood samples drawn simultaneously, was only slightly worse than that of the continuous measurement method itself. Thus, the precision of the measurement of enzyme activity seems to be the main determinant of the overall method. In conclusion, the described procedure of separation, homogenization, and enzyme measurement in human polymorphonuclear leukocyte meets the requirements of biochemical or clinical trials and can be recommended for clinical metabolic studies.

[Registration and analysis of airway pressure and gas flow in ventilated patients. The "Hyper-DAQ Respiration Mechanics Recorder"]

Respiratory data monitored in ventilated patients commonly consists of monitoring some inspiratory and expiratory pressures and volumes. For a more sophisticated analysis of respiratory mechanics in ventilated patients, a combined hardware and software system is presented that allows for continuous monitoring of airway pressure and gas flow. Gas flow is measured using a pneumotach. The "Hyper-DAQ" is an 8-channel 12-bit analog to a digital converter that can be connected to IBM PCs as well as to Macintosh computers using a standard RS 232 link. A special module consisting of three pressure transducers (airway pressure, differential pressure for a Fleisch head and ambient pressure) and five additional analog inputs is used for recording respiratory data. Once set up, the Hyper-DAQ records all the data in real time, independently of the host system that can query the data via the RS 232 link. The software runs on IBM and compatible PCs, as well as on Macintosh computers. The software simulates a strip-chart recorder and can be controlled by the keyboard and the mouse. We developed special software for the calibration of pressure and flow. Using models of the gas distribution in the lung compliance, resistance and lung time constants can be calculated from the raw data. For special purposes the data can be transferred to spread-sheet software. A mainstream CO2-detector connected to one of the additional analog inputs allows for additional data: alveolar ventilation, series deadspace, etc. The system presented can be recommended in routine work as well as for scientific studies in ventilated patients.

[Positive end-expiratory pressure (PEEP)]

PEEP has become a widely used ventilatory technique. The beneficial effects of PEEP were first described in asphyctic neonates, and it was later used in the treatment of cardiogenic pulmonary edema. Since the 1970s PEEP has been well established for the treatment of ARDS; the technique is also used for scoring the degree of severity of ARDS. Two mechanisms have been identified to explain pulmonary function and gas exchange following PEEP therapy: increasing FRC and alveolar recruitment. Both factors result in improvement in the ventilation/perfusion ratio with a consequent decrease in the intrapulmonary right-to-left shunt fraction. PEEP should be used in cardiogenic pulmonary edema as well as in ARDS; there are few contraindications. To choose the individual level of PEEP, PEEP should be titrated in 3- to 5-cm increments and its effects on haemodynamic function, pulmonary gas exchange and respiratory mechanics taken into account. In this article the effects of PEEP, its use and abuse are reviewed from a practical point of view.

Physician and nursing (personnel) requirements for ICUs. Therapeutic Intervention Scoring System (TISS) versus time requirements for patient care--a comparative study in an interdisciplinary surgical intensive care unit

OBJECTIVE

To measure total physician manoeuvres and total nursing manoeuvres in intensive care patients and to compare the results with calculated personnel requirements on the basis of TISS scores.

DESIGN

Open prospective study.

SETTING

Sixty-three ICU patients on two consecutive days.

MEASUREMENT

1. Total physician activities (TPM) in minutes/patient-day; total nursing manoeuvres (TNM) in min/patient-day. 2. TISS Calculation of personnel requirements on the basis of both parameters.

RESULTS

TPM averaged at 3.9 hours. No fixed correlation was established between TISS and TPM. TNM averaged 1,073 minutes/patient-day and demonstrated a good correlation with TISS.

CONCLUSIONS

Physician activities on a surgical ICU averaged 3.9 hours/patient-day. Nursing manoeuvres average 17.9 hours/patient-day. Individual measurements must be made before calculating personnel requirements on the basis of TISS scores.

[Maximal turnover rates of glycolysis enzymes and of the citrate cycle of separated granulocytes in the postoperative period]

The human granulocyte is easy to obtain and shows a nearly complete enzymatic equipment. It therefore represents an interesting model for in-vitro studies of metabolic disorders under various clinical conditions. In the presented study, the activities of several enzymes of glycolysis and citric cycle are measured in granulocytes separated from surgical patients (n = 10). Blood samples of 20 to 40 ml were drawn 6.5 +/- 4.8 hours after termination of surgical procedure. All patients were artificially respirated and nourished intravenously according to the results of indirect calorimetry. Hexokinase (HK), pyruvate kinase (PK), lactate dehydrogenase (LDH), and isocitrate dehydrogenase (IDH) were measured photometrically in the cell homogenate. The values were compared to those determined in a group of healthy, not-anesthetized persons, nourished and studied identically (n = 12). In granulocytes separated from patients following major surgery we found increased activities of HK (29.8 vs. 24.1 mU/mg protein in controls), LDH (2,484 vs. 1,868 mU/mg protein, p less than 0.01) and IDH (41.5 vs. 35 mU/mg protein, p less than 0.05), and a reduced activity of PK (1,623 vs. 2,265 mU/mg protein, p less than 0.01). Assuming that the alterations in enzyme activities of isolated granulocytes reflect metabolic alterations of the whole organism to a certain extent, the results can be interpreted as a decreased induction of PK by insulin, an increase of lactate recycling via Cori cycle (LDH), and a stimulated substrate flux in citric cycle (IDH). The separated human granulocyte is recommended as a model of posttraumatic metabolic disorders. It should be taken into consideration for studies leading to further improvement of nutrition during posttraumatic glucose mal-utilization.

Maximale Umsatzraten an Enzymen der Glykolyse und des Zitratzyklus von separierten Granulozyten in der postoperativen Phase

Der separierte ruhende polymorphkernige Leukozyt stellt aufgrund seiner minimal-invasiven Gewinnbarkeit sowie einer weitgehend kom-pletten enzymatischen Ausstattung ein attraktives Modell zur In-vitro-Erfassung von Stoffwechselveränderungen unter verschiedensten kli-nischen Bedingungen dar. In der vorliegenden Studie wurde untersucht, ob in den ersten Stun-den nach groβen chirurgischen Eingriffen Veränderungen in den maxi-malen Substratumsatzraten verschiedener Enzyme des Kohlenhy-dratstoffwechsels im separierten Granulozyten nachweisbar sind. Unter kaloriendeckender parenteraler Ernährung wurde 10 Patienten in der postoperativen Nachbeatmungsphase (6,5 ± 4,8 Stunden nach OP-Ende) 20 ml Blut zur Granulozyten-Separation entnommen. Im Zell-homogenat wurden die Enzyme Hexokinase (HK), Pyruvatkinase (PK), Laktatdehydrogenase (LDH) und Isozitratdehydrogenase (IDH) photometrisch bestimmt. Ein Kontrollkollektiv wacher gesun-der Personen (n = 12) wurde in gleicher Weise ernährt und untersucht. Es fanden sich postoperativ erhöhte Aktivitäten für HK (29,8 gegen-über 24,1 mU/mg Protein im Normalkollektiv), LDH (2484 bzw. 1868mU/mg Protein, p<0,01) und IDH (41,5 bzw. 35 mU/mg Protein, p<0,05), sowie eine reduzierte Aktivität für PK (1623 gegenüber 2265mU/mg Protein, p<0,01). Unter der Annahme, daβ die gefundenen Veränderungen in gewissem Rahmen Stoffwechselumstellungen des Gesamtorganismus widerspie-geln, lassen sich die Ergebnisse interpretieren als verminderte Insulin-wirksamkeit (PK), erhöhtes Recycling von Laktat im Corizyklus (LDH) und stimulierter Substratumsatz im Zitratzyklus. Die einge-hendere Nutzung des separierten Granulozyten als Modell metaboli-scher Reaktionen auf enzymatischer Ebene wird, auch unter dem Aspekt der Anpassung einer Ernährungstherapie an die Bedingungen der posttraumatischen Glukoseverwertungsstörung, empfohlen.