Effect of progressive haemodilution with hydroxyethyl starch, gelatin and albumin on blood coagulation

We have compared the effects of progressive (30% and 60%) in vitro haemodilution with hydroxyethyl starch (HES), gelatin (GEL) and albumin (ALB) with haemodilution using 0.9% saline in 96 patients by thrombelastography. Haemodilution with HES, GEL and ALB significantly (P < 0.05) compromised coagulation time (k), angle alpha and maximal amplitude (MA), with HES having the most negative effect at 30% and 60% haemodilution (P < 0.05). Haemodilution with saline significantly affected all variables of blood coagulation and clot lysis measured by thrombelastography, resulting in an increased coagulability at 30% haemodilution. To specifically assess the intrinsic effect of plasma expander molecules on blood coagulation and clot lysis, we analysed the difference between saline diluted blood (same degree of haemodilution) and plasma expander diluted blood. Prolongation of reaction time (r) was found for HES at 30% and 60% haemodilution and for ALB at 60% haemodilution and an increase in clot lysis by HES, GEL and ALB became evident. We conclude that HES, GEL and ALB compromised blood coagulation, while the maximum effect was found with HES.

Haemodynamic effects of pneumoperitoneum in elderly patients with an increased cardiac risk

We studied the haemodynamic changes induced by pneumoperitoneum (PP) in elderly patients with increased cardiac risk (ASA class III; n = 10; age 72.3 +/- 8.8 years, mean +/- SD, P < 0.05; group 2) and compared the results with patients at normal risk (ASA class I, II; n = 12; age 55.6 +/- 11.8 years; group 1). Thermodilution measurements were performed after induction of general anaesthesia (T1), after onset of PP (T2, intraabdominal pressure 14 mmHg) and after additional 15 degrees head-up tilt (T3). In both groups PP, as compared with T1, induced a significant increase in mean arterial pressure (MAP, mmHg, group 1: 77 +/- 14 to 96 +/- 18, P < 0.05/group 2: 75 +/- 10 to 102 +/- 18, P < 0.01), mean pulmonary artery pressure (MPAP, mmHg: 15 +/- 5 to 22 +/- 4, P < 0.01/18 +/- 3 to 25 +/- 5, P < 0.01), central venous pressure (CVP, mmHg: 7 +/- 2 to 15 +/- 3, P < 0.01/7 +/- 2 to 12 +/- 2, P < 0.01), pulmonary capillary wedge pressure (PCWP, mmHg: 9 +/- 4 to 16.3, P < 0.01/8 +/- 2 to 15 +/- 6, P < 0.01) and in systemic vascular resistance (SVR, dynes s cm-5: 1415 +/- 375 to 1873 +/- 412, P < 0.01/ 1502 +/- 360 to 2067 +/- 647, P < 0.01). Cardiac index (CI, L min-1 m-2: 2.3 +/- 0.3 to 1.9 +/- 0.3, P < 0.05/2.2 +/- 0.4 to 2.2 +/- 0.5 P = 0.76) and oxygen delivery index (DO2I, mL min-1 m-2: 388 +/- 54 to 324 +/- 61, P < 0.05/358 +/- 69 to 353 +/- 82, P = 0.77) decreased in group 1 but not in group 2. Heart rate, stroke Index, pulmonary vascular resistance, arteriovenous oxygen content difference and oxygen consumption index were unchanged. After head-up tilt MAP (mmHg, 92 +/- 15, P < 0.05/ 101 +/- 17, P < 0.01), MPAP (mmHg, 20 +/- 3, P < 0.01/22 +/- 4, P < 0.05), CVP (mmHg, 12 +/- 2, P < 0.01/10 +/- 2, P < 0.01) and PCWP (mmHg, 12 +/- 3, P < 0.05/12 +/- 5, P < 0.05) remained elevated compared with T1 in both groups, SVR (dynes s cm-5, 1575 +/- 372, P = 0.13/1793 +/- 528, P < 0.01) in group 2 only. No complications occurred. The results indicate that PP is associated with significant but relatively benign haemodynamic changes. Anaesthesia for laparoscopic cholecystectomy may be performed safely also in elderly ASA class III patients with increased cardiac risk. An adequate haemodynamic monitoring is recommended.

Video-assisted thoracoscopic volume reduction surgery in patients with diffuse pulmonary emphysema: gas exchange and anesthesiological management

Arterial blood gases were studied prospectively using continuous intraarterial blood gas monitoring during thoracoscopic volume reduction surgery (VRS) in 24 patients with advanced diffuse pulmonary emphysema. Additionally, the early postoperative course (48 h) of arterial blood gases was studied retrospectively. Twenty-six operations were performed using a combination of thoracic epidural and general anesthesia with left-sided double-lumen intubation for one-lung ventilation (OLV). Arterial blood gases were determined awake, during two-lung ventilation prior to surgery, during OLV (extreme values), and after tracheal extubation. Additionally, the extremes during the whole procedure were determined: avoiding excessive peak inspiratory pressures (26.4 +/- 7.0 cm H2O), minimum PaO2 was 77 +/- 39 mm Hg (mean +/- SD), maximum PaCO2 65 +/- 14 mm Hg (P < 0.0001 versus preoperative values), and minimum pHa 7.22 +/- 0.08 (P < 0.0001). One tension pneumothorax occurred during OLV. Immediate postoperative extubation was performed in 25 of 26 cases, reintubation was necessary in two cases. One patient with coronary artery disease died 36 h after surgery. Hypercapnia (maximum PaCO2 49 +/- 8 mm Hg, minimum pHa 7.37 +/- 0.04, P < 0.01) was still observed 48 h after surgery. These results demonstrate that adequate oxygenation can be preserved during OLV for VRS, but CO2 elimination is impaired. However, intraoperative hypercapnia and immediate postoperative tracheal extubation are well tolerated.

Effects of intravenous and oral clonidine on hemodynamic and plasma-catecholamine response due to endotracheal intubation

STUDY OBJECTIVE

To investigate the effects of intravenous (IV) versus oral clonidine on alterations of heart rate (HR), mean arterial pressure (MAP), cardiac output (CO), and plasma-catecholamines due to endotracheal intubation.

DESIGN

Randomized, double-blind, placebo-controlled study.

SETTING

University hospital surgery operating room.

PATIENTS

33 ASA physical status I patients were randomly assigned to either receive clonidine 3 micrograms/kg IV immediately prior to anesthesia induction, clonidine 4 micrograms/kg orally 90 minutes prior to anesthesia induction, or placebo.

INTERVENTIONS

Insertion of a 14 G cannula in a large cubital vein for the determination of plasma-catecholamines using local anesthesia. Insertion of a radial artery catheter for measuring blood pressure (BP) using local anesthesia. Transthoracic echocardiography determined CO.

MEASUREMENTS AND MAIN RESULTS

Heart rate, MAP, CO, and plasma-catecholamine concentrations were measured. Measurements were performed prior to induction, during intubation, and 10 minutes after intubation. During endotracheal intubation, MAP was significantly lower in the IV clonidine group compared with the placebo and the oral clonidine groups. Cardiac output was significantly lower in the IV clonidine group only. In contrast to the placebo group, norepinephrine plasma concentrations did not increase in either clonidine group. Significant alterations of epinephrine plasma concentrations due to intubation were not observed in either group. Hemodynamics after intubation were not impaired by clonidine treatment.

CONCLUSIONS

In conclusion, IV clonidine reduced stress response to endotracheal intubation compared with placebo. Oral clonidine at the dose used was less effective in blunting hemodynamic stress response than IV clonidine.

Bilateral volume reduction surgery for diffuse pulmonary emphysema by video-assisted thoracoscopy

We prospectively studied the surgical aspects, functional results, and complications of video-assisted bilateral thoracoscopic volume reduction surgery in patients with severe diffuse pulmonary emphysema.

METHODS

Fifteen men and five women with a mean age of 64 years (range 42 to 78 years) whose daily activity was substantially impaired by severe airflow obstruction and hyperinflation underwent thoracoscopic volume reduction surgery. The prospective preoperative assessment and postoperative assessment at 3 months included (1) pulmonary function studies, (2) grading of dyspnea, and (3) exercise performance; pulmonary function tests were also performed immediately before discharge from the hospital.

RESULTS

There was no perioperative mortality. All patients left the hospital after a median stay of 15 days (6 to 27 days). Only seven patients had a prolonged chest tube drainage time (>7 days). At 3 months the mean (+/- standard deviation) forced expiratory volume in 1 second had improved by 42% (+/-3.8%), from 0.80 L (+/-0.23) to 1.09 L (+/-0.28) (p < 0.001); residual volume had decreased from 5.8 L (+/-1.5) to 4.4 L (+/-1.0) (p < 0.001). Shortly before discharge the forced expiratory volume in 1 second was already 1.10 L (+/-0.26). The median 12-minute walking distance increased from 495 m (35 to 790 m) to 688 m (175 to 1035 m) (p < 0.001) and the mean maximal oxygen consumption from 10 ml/kg per minute (+/-2.5) to 13 ml/kg per minute (+/-2.3) (p < 0.0005). The patients reported a substantial relief of dyspnea with a mean decrease in the Medical Research Council score from 3.4 to 1.8.

Hemodilution tolerance in elderly patients without known cardiac disease

Hemodilution tolerance is not well defined in elderly patients. In 20 patients older than 65 yr and free from known cardiovascular disease, hemodynamic variables, ST segment deviation, and O2 consumption were determined prior to and after 6 and after 12 mL/kg isovolemic exchange of blood for 6% hydroxyethyl starch. The mean age of the patients was 76 +/- 2 yr (mean +/- SEM, range 66-88 yr). During hemodilution, hemoglobin decreased from 11.6 +/- 0.4 to 8.8 +/- 0.3 g/dL (P < 0.05). With stable filling pressures, cardiac index increased from 2.02 +/- 0.11 to 2.19 +/- 0.10 L.min-1.m-2 (P < 0.05) while systemic vascular resistance decreased from 1796 +/- 136 to 1568 +/- 126 dynes.s.cm-5 (P < 0.05) and O2 extraction increased from 28.0% +/- 0.9% to 33.0% +/- 0.8% (P < 0.05) resulting in a stable O2 consumption during hemodilution. No alterations in ST segments were observed in lead II during hemodilution. In lead V5, ST segment deviation became slightly less negative during hemodilution from -0.03 +/- 0.01 to -0.02 +/- 0.01 mV (P < 0.05). The moderate decrease in hemoglobin was fully compensated by both an increase in cardiac index and in O2 extraction. Electrocardiographic signs of myocardial ischemia were not observed in this population. In conclusion, isovolemic hemodilution to a hemoglobin value of 8.8 +/- 0.3 g/dL is well tolerated in elderly patients free from known cardiac disease at the ages of 65-88 yr.

Prospective study of the value of transbronchial lung biopsy after lung transplantation

Transbronchial lung biopsy (TBB) has become the gold standard for the diagnosis of acute rejection and cytomegalovirus (CMV) pneumonia in lung transplant recipients. The aim of this study was to assess the value of regular surveillance TBB in stable asymptomatic patients and to establish the role of TBB as a follow-up procedure 1 month after a previous pathological biopsy result. We prospectively evaluated 76 TBBs performed in 17 lung transplant recipients. A definite pathological results was found in 14 of 15 TBBs performed for clinical indications: CMV pneumonia (5), acute rejection grade > or = A2 according to the criteria of the International Society for Heart and Lung Transplantation (ISHLT) (4), bronchiolitis obliterans (3), and desquamative interstitial pneumonitis (2). Fifteen of 45 surveillance TBBs performed in asymptomatic patients revealed significant abnormalities. Ten episodes of acute rejection ISHLT grade > or = A2 and three episodes of CMV pneumonia detected by TBB had direct therapeutic consequences. Nine of 16 follow-up TBBs performed 1 month after a pathological biopsy result again showed relevant pathological findings. With the exception of one severe haemorrhage, no life-threatening complications occurred. Our results suggest that transbronchial lung biopsies performed on a regular basis after lung transplantation are important for the detection of asymptomatic and/or persistent acute rejection or injection. In the long-term, this strategy might be the most effective tool in reducing the incidence of bronchiolitis obliterans, which is still the main obstacle for further improvement of long-term survival after lung transplantation.

Positron emission tomography in drug evaluation: influence of three different catechol-O-methyltransferase inhibitors on metabolism of [NCA] 6-[18F]fluoro-L-dopa in rhesus monkey

We compared the influence of three different catechol-O-methyltransferase (COMT) inhibitors (CGP 28014, OR-611 and Ro 40-7592) on the metabolism of no-carrier-added (NCA) 6-[18F]fluoro-L-dopa (6-FDOPA) in one Rhesus monkey. All three COMT inhibitors improved 6-FDOPA availability in plasma, increased the specific uptake in the brain and thus improved 6-FDOPA uptake measurements using positron emission tomography (PET). Best results were obtained with Ro 40-7592.

[Isolated lung transplantation--evaluation of patients and initial results]

Between November 1992 and May 1994 we performed 10 single and 5 double lung transplants in patients with end-stage lung diseases due to lymphangioleiomyomatosis (4), cystic fibrosis (3), pulmonary hypertension (3), pulmonary fibrosis (3) and chronic obstructive lung disease (2). In the 13 patients (87%) surviving for median 245 (19-567) days, FEV1 improved from median 640 ml to 1410 ml and the 12-minute walk distance from median 315 to 1100 meters. 10 patients (77%) enjoy a good or even excellent quality of life. 2 patients died 11 and 62 days postoperatively, due to multi-organ failure and invasive pulmonary aspergillosis respectively. The main postoperative problems are fungal and cytomegalovirus infections and chronic rejection in the form of bronchiolitis obliterans. In Switzerland as elsewhere, lung transplantation has become an established modality for the management of end-stage diseases of the lung and pulmonary circulation.

[Isolated lung transplantation]

Over the last 10 years, single and bilateral lung transplantation has developed from an experimental technique to a valid therapy for patients with end-stage pulmonary or pulmonary-vascular disease. The main reasons for this progress are better defined selection criteria, improved operative technique and organ preservation, optimized peri- and postoperative management and more precise immunosuppressive and antiinfective therapy. Since 1983 more than 3000 lung transplantations have been performed worldwide with a 1- and 3-year survival rate of 70-90% and 60-70% respectively. In Switzerland 41 lung transplantations have been performed since 1992 with a 1-year survival rate of more than 80%. Indications, technique, treatment and results are discussed.

[Risk assessment and patient information before anesthesia]

In order to determine the risk of anesthesia the anesthesiologist has to assess both the physical and the psychological status of the patient. The essential basis of any preoperative medical evaluation are the history and complete physical examination of the patient. Few laboratory screening tests and, in case of pathological findings, specific diagnostic procedures will ensue. If possible, preoperative therapies must be considered in order to reduce the risk resulting from concomitant diseases. However, apart from the patients diseases, both the risks of the anesthetic and surgical procedures contribute to the overall perioperative risk. On the basis of the preoperative evaluation, the anesthesiologist determines the methods of anesthesia to be applied. He also informs the patient about the planned anesthesia, the sequence of further measures, the risk of anesthesia, and accompanying risks. The family doctor can help to facilitate the preoperative assessment by performing certain examinations himself and by providing the anesthesiologist with relevant informations. By giving a piece of advice to the patient he can help to prepare him for anesthesia and to reduce fear and apprehensiveness.

[Prognostic importance of early recorded somatosensory evoked potentials in patients not neurologically assessable after craniocerebral trauma]

By stimulation of the median nerve at the wrist we recorded the somatosensory evoked potentials (SEP) at several points between the midpoint of the clavicle and the scalp, overlying the area of sensorimotor cortex. The SEP of each side were graded (bilaterally normal SEP's: grade-1/1, pathological SEP's grade-2/1 to grade-4/4). The aim of these recordings is to judge the probability of survival in adult comatous patients in the early phase after a head injury. Our retrospective analysis of these recordings in 108 patients (collective 1988/89) shows a significant correlation of the SEP with the Glasgow Coma Scale score (GCS) (GCS > 8/SEP grade-3 or grade-4: p < 0.005) and the pupillary function (pupillary function disturbed uni- or bilaterally/SEP grade-3 or grade-4: p < 0.0005), being less pronounced with the intracranial pressure (ICP) too. In patients with lack of the component N20 death or vegetative outcome is significantly more frequent than if this component is present (p < 0.005). All the 7 patients without recognisable bilateral component N20 (SEP grade-4/4) died as a consequence of the initial brain injury. 7 out of 9 patients with unilateral lack of the component N20 combined with diminished amplitude ratio and delayed central conduction time (CCT) contralaterally (SEP grade-4/3) died or survived in a vegetative condition; none of them became independent. If the results of the analysis of the patient collective 1988/89 were applied to the patients of 1990 (n = 67) a good correlation between SEP and outcome was confirmed.(ABSTRACT TRUNCATED AT 250 WORDS)

Kidney procurement from non-heartbeating donors: transplantation results

To overcome the shortage of kidneys (kdn's) available for transplantation we reactivated kdn procurement from non-heartbeating donors (NON-HBD). In this study, we reviewed our results with 34 kdn's from NON-HBD, transplanted between 1985 and 1991, and compared these with 34 control kdn's procured from heartbeating donors (HBD) matched for age, sex, primary graft or retransplant and transplant year. There was no difference in cold ischemia time, preservation solutions used, duration and type of preoperative dialysis, number of HLA mismatches and serum antibody levels between the two groups. The only significant findings were a lower diuresis in the last hour in the donors in the NON-HBD group, and a significantly higher serum creatinine level compared to the HBD group. The 1-year patient and graft survival rates were 89.4% and 84.9% for the HBD group, and 78% and 76.1% for the NON-HBD group respectively. There was need for dialysis support in the first posttransplant week in 10 out of 34 (29%) recipients in the HBD and 17 out of 34 (50%) recipients in the NON-HBD group. Primary non-function was observed in 1 of 34 (3%) recipients in the HBD group versus 3 of 34 (9%) in the NON-HBD group. None of the differences were statistically significant. There was also no difference in average serum creatinine levels at days 1, 3, and 7, at 1 month and at 1 year between the HBD and NON-HBD groups. In the NON-HBD group 6 of 34 kdn's (18%), 5 of which were retransplants, showed vascular rejection, 5 of them associated with haemolytic uremic syndrome (thrombotic microangiopathy); 2 of these 6 kdn's recovered, and 4 failed (2 with primary non-function). This important observation needs to be investigated further. The results is this study showed, however, that good short- and long-term results can be achieved with kdn's from NON-HBD. We concluded that organ procurement from NON-HBD is an adequate approach to an important cadaver donor source that in general is not effeciently used, but could significantly increase the number of kdn grafts in most transplant programs.

[Anesthesia for ambulatory procedures]

Ambulatory surgery and anesthesia continued to grow and develop over the last few years: Longer lasting and more complex diagnostic and therapeutic procedures are being performed on an outpatient basis. In addition, outpatient procedures, being less disruptive to the patient's everyday life, are of potential benefit especially for children and elderly patients. The proper selection and evaluation of these patients from the anesthesiological and surgical points of view are very important with regard to successful ambulatory interventions. The preoperative assessment is obviously essential. Good communication and teamwork between anesthesiologists, surgeons and admitting doctors are necessary. Patients should be informed early, i.e. before the day of operation, about the planned procedures (fasting periods, adult person necessary to accompany the patient home, etc.), and their written consent should be there. During the preoperative personal interview, the anesthesiologist identifies risk factors which may influence the management and outcome of the anesthetic procedure. Outpatients profit from a short-acting anxiolytic and sedative premedication before entering the operation room. The choice of the anesthetic procedure itself is made individually. An adequate intra- and postoperative monitoring is essential. A checklist with exact discharge criteria is helpful in practice.

[Enoximone as an alternative to mechanical circulatory support prior to heart transplantation]

Enoximone, a relatively new type III phosphodiesterase (PDE III) inhibitor with combined positive inotropic and vasodilating properties, was used as a pharmacological bridge to heart transplantation in a patient with severe dilatative cardiomyopathy (ejection fraction 11-13%), who developed cardiogenic shock refractory to conventional therapy with catecholamines and vasodilators. Enoximone led to an 88% increase in cardiac index (from 1.6 to 3.0 l/min.m2). Despite a noticeable rise in heart rate, stroke index increased by 57%. Systemic vascular resistance decreased by 48% without any relevant change in mean arterial pressure. Cardiac filling pressures remained high. Oxygen transport doubled and oxygen extraction ratio decreased by 10%. Apart from a decrease in arterial oxygen tension (from 15.8 to 12.8 kPa [119 to 96 mm Hg]), no other side effects were noted. Withdrawal of catecholamine therapy did not cause any relevant haemodynamic changes. Although complications arose from an uncontrolled septic state, orthotopic heart transplantation was performed with success 74 hours after initiation of enoximone therapy. As the PDE III inhibitor enoximone exerts its potent inotropic and vasodilating effects without requiring adrenergic receptor activation, it may be used as an alternative to mechanical support in patients who develop cardiogenic shock resistant to catecholamines while awaiting heart transplantation.

[X chromosome-linked mental retardation with fragile X chromosome and macro-orchidism]

Description of the first Swiss family with the new syndrome of X-linked mental retardation. The three brothers described are the first of all males traced back for four generations to be affected. In two of the brothers macroorchidism and the fragile X-chromosome were demonstrated, while the third brother died before diagnosis. As expected, the fragile X was not demonstrable in the 75-year-old mother of the three brothers.