Ehrenfried Schindler

The use of an anesthesia information management system for prediction of antiemetic rescue treatment at the postanesthesia care unit.

We used an anesthesia information management system (AIMS) to devise a score for predicting antiemetic rescue treatment as an indicator for postoperative nausea and vomiting (PONV) in the postanesthesia care unit (PACU). Furthermore, we wanted to investigate whether data collected with an AIMS are suitable for comparable clinical investigations. Over a 3-yr period (January 1, 1997, to December 31, 1999), data sets of 27,626 patients who were admitted postoperatively to the PACU were recorded online by using the automated anesthesia record keeping system NarkoData® (IMESO GmbH, Hüttenberg, Germany). Ten patient-related, 5 operative, 15 anesthesia-related, and 4 postoperative variables were studied by using forward stepwise logistic regression. Not only can the probability of having PONV in the PACU be estimated from the 3 previously described patient-related (female gender, odds ratio [OR] = 2.45; smoker, OR = 0.53; and age, OR = 0.995) and one operative variables (duration of surgery, OR = 1.005), but 3 anesthesia-related variables (intraoperative use of opioids, OR = 4.18; use of N2O, OR = 2.24; and IV anesthesia with propofol, OR = 0.40) are predictive. In implementing an equation for risk calculation into the AIMS, the individual risk of PONV can be calculated automatically.

Catheterization of the radial or brachial artery in neonates and infants

Background : In neonates and small children, percutaneous insertion of arterial catheters may be very difficult because of the small diameter of the arteries. Multiple attempts at cannulation are common and may be a predictor of serious adverse events following arterial cannulation. As an endartery, the brachial artery is usually not recommended for cannulation. However, limited data exist about brachial artery catheterization in neonates and young children. In this retrospective study, we report our experience with arterial indwelling catheters placed in neonates and small children prior to surgery for congenital heart defects.

Heart transplantation in children and infants: Short-term outcome and long-term follow-up

Abstract: Since 1988, 82 heart transplants have been performed in 80 infants and children. Diagnoses pretransplant were: hypoplastic left heart syndrome (HLHS) (n = 43); cardiomyopathy (n = 19); endocardial fibroelastosis (n = 6); and other complex congenital heart diseases (n = 12). Age at transplantation was < 1 yr in 61 patients. Overall survival rate was 79% at 1 yr and 73% at 5 and 10 yr. To date, 20 patients have died after transplantation. Causes of death were: rejection (eight patients); right ventricular failure (four patients); transplant coronary artery disease (TCAD) (two patients); and other causes (six patients). In the majority of patients somatic growth is not impaired, and renal function is reduced (but stable) in all patients. Two patients developed post‐transplant lymphoproliferative disease, which was treated successfully. Major long‐term morbidity is neurologic deficit – severe in three patients and minor in six. TCAD was present or suspected in six surviving patients. We conclude that heart transplantation in infants and children can be performed with good early and late results. Quality of life is excellent in most patients. TCAD, however, will become an increasing problem in the long term.

Influence of Intravenous Administration of Angiotensin- Converting Enzyme Inhibitor Enalaprilat on Cardiovascular Mediators in Cardiac Surgery Patients

The renin-angiotensin system (RAS) is important in controlling and maintaining cardiovascular homeostasis. In a randomized, prospective study, the response to intravenous (IV) administration of the angiotensin-converting enzyme (ACE) inhibitor enalaprilat (0.06 mg/kg) on important controllers of the circulation was investigated in 14 patients undergoing aortocoronary bypass grafting with a mean arterial blood pressure (MAP) > 85 mm Hg after induction of anesthesia. Fourteen patients received saline solution as placebo (control group). Endothelin (ET), atrial natriuretic peptide (ANP), catecholamine (epinephrine, norepinephrine) plasma levels, and ACE activity were measured from arterial blood sampled before injection of enalaprilat or NaCl solution (baseline values), 10 min and 30 min thereafter, immediately before the start of cardiopulmonary bypass (CPB), immediately after CPB, and at the end of surgery. MAP, heart rate (HR), cardiac index (CI), and systemic vascular resistance (SVR) were also monitored. ACE activity was similar at baseline in both groups; after IV injection of enalaprilat, it significantly decreased (from 35.1 +/- 11 to 4.4 +/- 1.0 U centered dot min-1 centered dot L-1 30 min after injection) and remained reduced until the end of the operation (295 +/- 31 min after injection). ANP plasma levels were increased beyond normal (> 100 pg/mL) at baseline in both groups. They increased significantly in the control patients, but remained almost unchanged in the enalaprilat-treated patients within the entire study period. Plasma concentration of ET also increased only in the control group and was increased after CPB (8.6 +/- 1.2 pg/mL at the end of the operation). Starting from similar catecholamine plasma levels at baseline, epinephrine and norepinephrine concentrations increased in the control patients, being significantly different from the plasma levels of the enalaprilat-treated group. IV enalaprilat significantly decreased MAP from 100 +/- 7 mm Hg at baseline to 70 +/- 7 mm Hg prior to start of CPB without showing a reflex increase in HR. CI increased and SVR decreased in the prebypass period in these patients (P < 0.05). It is concluded that IV administration of enalaprilat was effective in reducing blood pressure in cardiac surgery patients. In addition, it beneficially influenced endocrinologic regulators of macro- and microcirculation by blunting the increase of systemic and local vasoactive substances, which is normally observed in this situation. (Anesth Analg 1995;80:480-5)

Influence of aprotinin on the thrombomodulin/protein C system in pediatric cardiac operations

Thirty consecutive children scheduled for pediatric cardiac operation with cardiopulmonary bypass were included in the study. Before the operation, the patients were randomly divided into two groups: with aprotinin (n = 15, 30,000 U/kg after induction of anesthesia, 30,000 U/kg added to the prime of the cardiopulmonary bypass or without aprotinin (n = 15). Thrombomodulin, (free) protein S, protein C, and thrombin/antithrombin III complex were measured from arterial blood samples taken after induction of anesthesia (at baseline, before aprotinin) and before, during, and after cardiopulmonary bypass until the first postoperative day. Standard coagulation parameters (antithrombin III, fibrinogen, platelet count, and partial thromboplastin time) were without differences between the groups. Thrombomodulin plasma concentrations were within normal range ( < 40 micrograms/L) and were similar in both groups at baseline. During cardiopulmonary bypass and until 5 hours after cardiopulmonary bypass, however, thrombomodulin plasma levels were significantly lower in the children treated with aprotinin. No further differences were observed on the first postoperative day. Protein C and protein S plasma levels did not differ between the two groups. Thrombin/antithrombin III-complex plasma concentrations increased significantly during cardiopulmonary bypass, however, without showing differences between children with (225 +/- 49 micrograms/L) and without (149 +/- 31 micrograms/L) aprotinin treatment. Blood loss and the need for homologous blood and blood products did not differ significantly between the two groups. We concluded that administration of aprotinin resulted in reduced thrombomodulin plasma levels in pediatric patients undergoing cardiac operation without altering protein C/protein S plasma concentration. The exact role of aprotinin in endothelium-derived coagulation should be further studied.

Controlled hypercapnia during one-lung ventilation in patients undergoing pulmonary resection

Background: In a pilot study, the haemodynamic and gas exchange effects of acute hypercapoia during one‐lung ventilation in thoracotomy patients were investigated. The effects of normocapnic one‐lung ventilation (OLV‐N) on haemodynamics and pulmonary gas exchange were compared with those of hypercapnic one‐lung ventilation (OLV‐H) in 14 patients undergoing pulmonary lobectomy.

Does aprotinin influence endothelial-associated coagulation in cardiac surgery?

Aprotinin has been reported to reduce bleeding in cardiac surgery patients. Its mechanisms of action on coagulation have not been fully elucidated. In a prospectively randomized study of 40 patients undergoing elective aortocoronary bypass grafting, the influence of high-dose aprotinin (2 million IU of aprotinin before CPB, 500,000 IU/h until the end of operation, 2 million IU added to the prime) (N = 20) on endothelial-related coagulation was compared to a nontreated control group (N = 20). Thrombomodulin (TM), protein C and (free) protein S as well as thrombin/antithrombin-III (TAT) plasma concentrations were measured by enzyme-linked immunosorbent assays (ELISA) before the aprotinin infusion, before cardiopulmonary bypass (CPB), during CPB and after CPB, at the end of surgery, 5 hours after CPB, and on the first postoperative day. All standard coagulation parameters (AT-III and fibrinogen plasma levels, platelet count, partial thromboplastin time) did not differ between the two groups. At baseline, TM plasma levels were within the normal range (< 40 ng/mL) and similar in both groups. During CPB, TM plasma concentrations decreased similarly in both groups (aprotinin: 18 +/- 6 ng/mL, control: 17 +/- 7 ng/mL) followed by a comparable increase in the postbypass period until the first postoperative day (aprotinin: 60 +/- 10 ng/mL, control: 53 +/- 11 ng/mL). Protein C and (free) protein S plasma levels also showed no differences between the two groups. On the first postoperative day, baseline values for protein C and protein S had not yet been reached.(ABSTRACT TRUNCATED AT 250 WORDS)

Surgical management of congenital heart disease: evaluation according to the Aristotle score.

OBJECTIVE The Aristotle basic complexity (ABC) score (1.5-15 points) is the sum of potentials for early mortality, morbidity and anticipated surgical technique difficulty. The Aristotle comprehensive complexity (ACC) score (1.5-25 points) is the sum of ABC score and patient-adjusted complexity score; it comprises six complexity levels. We used the ACC score to evaluate quality in surgical management of congenital heart disease. METHODS Procedures performed in year 2002 and 2007 were analysed. Proportion of procedures requiring at least 1 week of stay in the intensive care unit was chosen as the marker of morbidity. We adopted threshold duration of 120 min for cardio-pulmonary bypass (CPB) cases and the same duration for operations without CPB as surrogate of surgical technical difficulty. The ACC scores were correlated to mortality, morbidity and technical difficulty. RESULTS This study included 758 patients who underwent 787 primary procedures. The mean ABC and ACC scores amounted to 7.61+/-2.46 and 9.51+/-3.84. Early mortality was 3.05% (24/787), 95% confidence interval (CI): 1.97-4.51%. Zero at ACC levels 1 and 2, it increased from 1.2% (2/161) for level 3 up to 22.2% (2/9) for level 6. Morbidity index was evaluated at 25.9% (204/787), 95% CI: 22.9-29.1%. 1.9% at level 1, it escalated up to 77.8% at level 6. Index of technique difficulty was estimated at 35.2% (277/787), 95% CI: 31.8-38.6%, ranging from 4.8% for level 1 to 66.7% for level 6. A high correlation was found between the ACC scores and mortality, indices of morbidity and technique difficulty, Spearmans correlation coefficient r being 0.9856, 1 and 0.9429, respectively. Mortality (p=0.037) and morbidity (p=0.041) were lower in year 2007 than in 2002 with ABC (p=0.18) and ACC (p=0.37) surgical performance being not significantly different. CONCLUSIONS The Aristotle score is still under development. Morbidity evaluation should be ideally based on observed postoperative complications; estimation of surgical technical difficulty chosen in this study may not be generalised. Nevertheless, the actual Aristotle comprehensive complexity score, as evaluated in its three components, accurately determined the outcome of surgical management of congenital heart disease. It appears to be an adequate tool to evaluate quality in paediatric cardiac surgery, over time.

Effects of low-dose dopexamine on splanchnic oxygenation during major abdominal surgery.

OBJECTIVE To study the influence of low-dose dopexamine on splanchnic oxygenation during major abdominal surgery. DESIGN Prospective, randomized, placebo-controlled study. SETTING University hospital. PATIENTS Eighteen adult patients undergoing elective major abdominal surgery. INTERVENTIONS The patients received either dopexamine at 1 microg/kg/min (group A, n = 9) or 0.90% saline as control (group B, n = 9). MEASUREMENTS AND RESULTS To assess the splanchnic oxygenation, intestinal tissue PO2 (PtissO2) and gastric intramucosal Pco2 (PmucCO2) were measured, and the PCO2 gap (PmucCO2 - PaCO2) was calculated at baseline (T1) and after an infusion period of 60 mins (T2). There was no difference between the groups in the global oxygen transport parameters. Low-dose dopexamine increases PtissO2 on the serosal side of the small bowel (deltaPtissO2, 17+/-24 mm Hg in group A vs. -5+/-10 in group B). The changes in PtissO2 at the serosal side of the colon after dopexamine demonstrated a nonsignificant increase (deltaPtissO2, 7+/-11 mm Hg in group A vs. -11+/-23 mm Hg in group B). In both groups, the Pco2 gap (group A, 6+/-7 mm Hg [T1] and 5+/-6 mm Hg [T2], vs. group B, 9+/-10 mm Hg [T1] and 12+/-10 mm Hg [T2]) remained unchanged compared with the baseline. CONCLUSION It is concluded that low-dose dopexamine improves PtissO2 at the serosal side of the gut, preferably at the small bowel. However, low-dose dopexamine did not improve gastric PmucCO2.

Modulation of somatosensory evoked potentials under various concentrations of desflurane with and without nitrous oxide.

Continuous measurement of somatosensory evoked potentials (SEP) by means of characteristic changes in the signal pattern makes it possible to identify cerebral or spinal cord ischemia during critical phases of the operative procedure. A correct interpretation of the measurements is only possible, however, if the influence of drugs acting on the central nervous system is known. The authors were able to show that inhaled anesthetics have an impact on latencies and response amplitudes. This study examined the influence of various concentrations of desflurane on the conduction of SEP of the Median nerve. In addition, the authors determined how the supplementation of nitrous oxide (N2O) influences the stimulus response of the medianus nerves SEP. Desflurane has been shown to produce dose-dependent increases in SEP latency (data in part for latency N2O: 0.5 minimum alveolar concentration [MAC] = 20.8 +/- 0.9; 1.5 MAC = 22.2 +/- 1.5; 1.5 MAC/N2O= 23.8 +/- 1.5) and decreases in amplitude, whereas cervically recorded subcortical SEP components are minimally influenced by desflurane. When nitrous oxide is added, there were marked reductions in amplitude (p<0.01) of the cortical stimulus response (1.5 MAC = 2.4 +/- 0.9; 1.5 MAC/N2O = 1.1 +/- 1). It can therefore be recommended that supplementation with N2O should be avoided in the presence of low initial amplitudes. Based on the studys results, the use of desflurane (up to 1.0 MAC) seems to be compatible with intraoperative monitoring of median somatosensory evoked potentials.