PubMed Health⌕ Search

Biomedical subjects

W Heinrichs

Publications and source records attributed to W Heinrichs.

At least 19 recordsLinked to original sources
PubMed1997

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.

Adolescent↗
PubMed1996

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

UNLABELLED: 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.

Aged↗
PubMed1996

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

UNLABELLED: 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.

Anesthesia↗
PubMed1996

[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.

Adult↗
PubMed1996

[Combination of intravenous patient-controlled analgesia with epidural anesthesia for postoperative pain therapy].

The aim of this study was to prove the hypothesis that a combination of epidural anaesthesia with intravenous patient-controlled analgesia (PCA) could improve perioperative pain management. Patients of the urological department undergoing lower abdominal surgery were randomized for two different pain managements. Patients of group 1 (n = 37) were narcotized, intubated and ventilated for the operation; arriving at the recovery room, they were given a PCA-pump, the drug used was piritramide and the parameters were bolus 2.5 mg, blocking time 20 minutes and no basal infusion rate. In group 2 (n = 37) an epidural catheter was inserted preoperatively followed by narcosis with intubation and ventilation. Additionally, epidural anaesthesia was performed intraoperatively using bupivacaine 0.5%. For postoperative pain management, patients of group 2 were also given a PCA-pump (same parameters as mentioned above) and a continuous epidural infusion was started additionally (bupivacaine 0.1875%, infusion rate 8 ml/h). Patients were monitored at the urological ICU for 36 hours. Assessment of pain (6-degree scale), grade of sedation (4-degree scale), cumulative doses of piritramide, heart rate, blood pressure, respiratory rate, in group 2 additional motoric function (Bromage) and degree of epidural anaesthesia were recorded at fixed time intervals: 0, 1, 2, 3, 5, 8, 11, 15, 19, 24, 28, 32, 36 hours. There was no difference regarding age of patients or type of operation. Assessment of pain showed a significant pain reduction in group 2 compared to group 1 during the first 8 hours. This result was underlined by a significantly smaller dose of piritramide. All other parameters showed no differences except lower blood pressure and heart rate in group 2 for the first three hours. The benefits of better pain management contrast with the risks resulting from combining the two techniques. In our patients we found an improvement of pain management in the early postoperative period. The combination of epidural anaesthesia with intravenous patient-controlled analgesia can be regarded as a further possibility for treating postoperative pain in the sense of "balanced pain management".

Adult↗
PubMed1995

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.

Anesthesia↗
PubMed1995

[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.

Absorption↗
PubMed1994

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.

Adult↗
PubMed1994

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)

Equipment Design↗
PubMed1993

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.

Centrifugation, Density Gradient↗
PubMed1993

[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

Abdomen↗
PubMed1993

[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.

Humans↗
PubMed1993

[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.

Anesthesia, Conduction↗
PubMed1993

[Intraoperative cardiopulmonary disorders during esophagectomy in relation to the surgical technique].

Twenty-one healthy female sheep were anaesthetised in a standard technique with ketamine, dehydrobenzperidol and etomidate. In seven sheep an endoscopic esophagectomy was made (group 1), in seven a blunt esophagectomy (group 2) and in a further seven a thoraco-abdominal esophagectomy (group 3). ECG monitoring, invasive blood pressure measurement, measurement of the central venous pressure and the pulmonary artery pressure with estimation of cardiac output, arterial and mixed venous blood gas analyses were made. The measurement times were: ZDM 1 = preoperative, ZDM 2 = after laparotomy, ZDM 3 = after cervical esophagus preparation or thoracotomy, ZDM 4 = after esophagectomy, ZDM 5 = after inflation of the lungs and ZDM 6 = after a second exploration of the esophagus bed (only groups 1 and 2). Finally the sheep in groups 1 and 2 were thoracotomised on the right side. In group 1 the measurement parameters remained largely unchanged during the entire experiment. In group 2 significant and by the end of the operation irreversible pathological changes occurred immediately after the blunt esophagus resection (ZDM 4): decrease of MAP, paO2 and CO, increase of AaDO2 and PVR. In group 3 similar changes were observed, they began, however, during ZDM 3. The measurement results can be explained in accordance with the operative anatomical findings. How far postoperative pulmonary complications can be avoided in patients with the endoscopic technique must be demonstrated in clinical use.

Animals↗