PubMed Health⌕ Search

Biomedical subjects

D Kettler

Publications and source records attributed to D Kettler.

At least 55 records · Page 3Linked to original sources
PubMed1997

Use of modified fluid gelatin and hydroxyethyl starch for colloidal volume replacement in major orthopaedic surgery.

We have compared 6% hydroxyethyl starch (HES 200/0.5) with 3% modified fluid gelatin (MFG) for volume replacement in major orthopaedic surgery and studied the effects on haemodynamic state, colloid osmotic pressure, blood clotting and plasma homeostasis. Using a controlled, randomized, single-blind clinical design, we studied 46 consecutive patients undergoing major elective orthopaedic hip surgery. The two groups were comparable in age, body weight and duration of surgery. Patients were maintained haemodynamically stable using both HES and MFG over the entire study. Fluid balance and colloidal replacement volumes were comparable in both groups (median perioperative infusion volume: HES 2500 ml, MFG 2400 ml). Laboratory variables were not clinically different. We conclude that both colloidal solutions were comparable in volume efficacy and effects on plasma oncotic pressure, clotting and plasma homeostasis. In the small number of patients studied, 6% HES 200/0.5 was found to be safe when administered in amounts corresponding to the currently accepted maximum daily dose in Germany and France of 33 ml/kg body weight and 2.0 g/kg body weight, respectively.

Adult↗
PubMed1997

Pharmacodynamic modelling of the analgesic effects of piritramide in postoperative patients.

BACKGROUND: The concentration-effect relationship of piritramide, a synthetic opioid analgesic predominantly used for postoperative analgesia and analgosedation, has not been reported so far. METHODS: Twenty-four patients of both genders aged 58.1 (11.7) yr (mean (SD)) received inhalational anaesthesia for abdominal surgery. Postoperative pain was assessed with a visual analogue scale (VAS). Analgesia was provided with piritramide, infused at a rate of 7 micrograms.kg-1.min-1 until analgesia was considered sufficient (VAS < 25) or up to a maximum dose of 0.2 mg/kg. The plasma concentrations of piritramide were determined by gas chromatography. An inhibitory fractional sigmoid Emax-model was used to describe the relation between effect site concentration and perceived pain. RESULTS: The equilibration half-life between plasma and effect site concentrations (T1/2 (keo)) was 16.8 min (median; range: 4.4-41.6 min). The steady-state plasma concentration required to produce 50% of maximum analgesia (EC50) was 12.1 ng/ml (range: 2.9-29.8 ng/ml) and correlated with initial pain intensity. The slope factor gamma was 1.9 (range: 0.5-6.1) and increased with age. Clinically relevant respiratory depression did not occur. Due to the relatively large equilibration half-life of the effect compartment, the context-sensitive half-time of the effect site concentrations after short-time administration (< 2 h) clearly exceeded those of alfentanil, sufentanil, and fentanyl. CONCLUSIONS: The analgesic effect of piritramide was adequately described by an inhibitory fractional Emax-model. In order to overcome the pronounced hysteresis, piritramide should initially be administered as an intravenous bolus of at least 5 mg.

Adult↗
PubMed1997

Ethical aspects of prehospital CPR.

Obvious reasons to withhold CPR are signs of death or fatal trauma. If there is any doubt about the appropriateness of CPR, resuscitative measures should be performed. However, CPR should not be attempted like a reflex action, without considering the individual circumstances, the patient's preferences and his prognosis. Age or preexisting diseases are factors that might affect the withholding or withdrawing of CPR, although the decision should not be based solely on these factors, but on criteria with a better predictive value, such as the initial cardiac rhythm and the course of CPR application. Changes in cardiac rhythm might be of prognostic value, because rhythms other than ventricular tachycardia or fibrillation tend to predominate the longer an arrest is in progress. The outcome worsens with prolonged CPR. A termination of unsuccessful CPR after 30 to 45 minutes seems to be reasonable. With respect to the preservation of life as one of the main goals of medicine we have to accept the ethical dilemma that CPR is performed in a number of patients although retrospectively it turns out to have been inappropriate or unwanted by the patient. Nevertheless, therapeutic interventions might be stopped later on after additional information has been obtained. Ethical principles should be taken into account as an action guide when considering the decision to withhold or to terminate resuscitative efforts. However, a detailed and individual ethical analysis in case of conflict is difficult and often impossible in the prehospital emergency situation.

Age Factors↗
PubMed1996

[Is reduction of intraoperative heat loss and management of hypothermic patients with anesthetic gas climate control advisable? Heat and humidity exchangers vs. active humidifiers ina functional lung model].

UNLABELLED: Heated humidifiers (HH) as well as heat and moisture exchangers (HME) are commonly used in intubated patients as air-conditioning devices to raise the moisture content of the air, thus preventing mucosal damage and heat loss resulting from ventilation with dry inspired gases. In contrary to HME, HH are able to add heat and moisture to the inspired air in surplus, which is often stressed as an advantage in warming hypothermic patients or reducing major heat losses, e.g., during long operations. The impact of air conditioning on the energy balance of man was calculated comparing HME and HH. METHODS: The efficiency of a HME (Medisize Hygrovent) and a HH (Fisher & Paykel MR 730) was evaluated in a mechanically ventilated lung model simulating the physiological heat and humidity conditions of the upper airways. The gas flow from the central supply was dry; the model temperature varied between 32 and 40 degrees C. By using a HH in the inspiratory limb, a circle system was simulated with water-saturated inspired air at room temperature. The water content of the ventilated air was determined at the tracheal tube connection using a fast, high-resolution humidity meter and was compared with the moisture return of the HME. The energy balance was calculated according to thermodynamic laws. RESULTS: Both HME and HH were able to create physiological heat and humidity conditions in the airways. With the normothermic patient model, the moisture return of the HME was equal to that of the HH set at 34 degrees C. Increasing the heating temperature resulted only in reduced water loss from the lung; heat and water input in the normothermic model was not possible. This was only effective with almost negligible amounts under hypothermic patient model conditions. DISCUSSION: The water content in the inspired and expired air is the most important parameter for estimating pulmonary heat loss in mechanically ventilated patients. In adults (minute volume approximately 71/min) the main fraction of pulmonary heat loss results from water evaporation from the airways (approximately 6 kcal/h), whereas the heat loss due to convection is negligible (approximately 1.2 kcal/h). In intubated patients ventilated with dry air, the heat loss increases to approximately 8 kcal/h due to greater water evaporation from the airways. Both HME and HH are able to reduce the pulmonary heat loss to 1-2 kcal/h. In normothermic as well as hypothermic patients, HH do not offer significant advantages in heat balance compared to effective HME. In conclusion, air conditioning in intubated patients is neither a powerful too for maintaining body temperature during long-lasting anaesthesia nor a sufficient method of warming hypothermic patients in intensive care units.

Air Conditioning↗
PubMed1996

Influence of different types of recovery positions on perfusion indices of the forearm.

BACKGROUND: Basic life support guidelines of the European Resuscitation Council (ERC) suggest a modified type of recovery position compared to that recommended by the American Heart Association (AHA). However, anecdotal reports and the results of a small study by Fulstow and Smith (Resuscitation 1993; 26: 89-91) gave evidence that the new ERC position may cause an impairment of perfusion of the lower forearm. The aim of our study was to evaluate the effects of different recovery positions on arterial perfusion and venous drainage of the forearm. METHODS: We placed 20 young healthy volunteers randomly in either ERC or AHA position for 15 min first, and in the other position thereafter. Before and between volunteers were positioned supine. In a second series 10 volunteers were positioned according to the same protocol in semiprone positions as described by Morrison, Mirkhur and Craig (MMC), and Rautek's position, respectively. Forearm perfusion indices of the dependent arm were continuously assessed by photoplethysmographic pulsatility change, photoplethysmographic volume change, invasive peripheral venous pressure and non-invasive blood pressure amplitude. Subjective discomfort was assessed non-qualitatively. RESULTS: All indices of arterial perfusion demonstrated an impairment of arterial inflow in ERC, MMC and Rautek's position as well as venous congestion in these three positions. On the contrary, AHA position was associated with no significant changes of arterial flow and only moderate, insignificant signs of venous congestion. CONCLUSION: The results of this study suggest that AHA position causes less circulatory disturbances than the ERC, MMC and Rautek's positions.

Adult↗
PubMed1996

ACD versus standard CPR in a prehospital setting.

BACKGROUND: Animal and human studies in cardiac arrest demonstrate significant improvements in systolic blood pressure, coronary perfusion pressure and total brain and myocardial blood flow with active compression-decompression (ACD) cardiopulmonary resuscitation (CPR). The results of recent studies in patients with out-of-hospital cardiac arrest and use of ACD-CPR are non-uniform and require supplementation. METHODS: In a retrospective non-randomised design, 152 adult patients with prehospital cardiac arrest, not caused by trauma or hypothermia, were studied. Compressions were performed according to the recommendations of the American Heart Association. Three ACD devices were assigned to seven rescue units changing monthly. Study end-points were the rates of return of spontaneous circulation (ROSC), admission to hospital, survival at 24h, hospital discharge and neurologic outcome. RESULTS: 70 (46%) patients underwent standard (STD) CPR and 82 (54%) patients were treated with ACD-CPR. Both groups were comparable with regard to age, sex, witnessed cardiac arrests, bystander CPR, cause of arrest, time intervals, number of defibrillations, and total amount of epinephrine. No significant differences in outcome could be found: 20 patients (29%) who received STD-CPR, and 14 patients (17%) who underwent ACD-CPR survived to hospital discharge. Neither at other end-points nor in any subgroups could any significant differences be discovered. Patients regaining ROSC showed a significant difference in favour of STD-CPR for the end-points of hospital admission, 24-h survival and hospital discharge. CONCLUSION: No significant differences in hospital discharge and neurological outcome were found between STD-CPR and ACD-CPR.

Adult↗
PubMed1996

[Diagnosis of magnesium deficiency in intensive care patients].

AIM: Magnesium deficiency was investigated in critically ill patients, comparing measurements of plasma concentrations with the results obtained by the magnesium tolerance test. DESIGN AND METHODS: 20 critically ill patients (5 females, 15 males) between the ages of 27 and 86 were investigated. Magnesium plasma concentrations were determined before the magnesium tolerance test according to Ryzen was performed. For this purpose, magnesium sulfate (0.1 mmol/kg) was infused intravenously over four hours. Renal magnesium excretion was measured in the 24 h urine beginning at the start of the infusion. Magnesium concentrations in plasma and urine were determined using atomic absorption spectrophotometry. MAIN RESULTS: In 12 patients magnesium plasma concentrations were decreased to 0.58-0.79 mmol/l. 6 patients showed values within the normal range of 0.80 to 1.0 mmol/l. In 2 patients the plasma concentration was increased to 1.07 and 1.27 mmol/l. Parenteral magnesium tolerance testing revealed a considerable magnesium deficiency by retention of 65-100% of the loading dose in 14 of the 20 patients. The remaining 6 patients retained 23-48% of the loading dose, thus demonstrating a moderate magnesium deficiency. CONCLUSION: Determination of magnesium plasma concentration appears suitable as an informative preliminary survey, since low values are reliable indicating a magnesium deficiency. However, this study confirms that normal magnesium plasma concentrations do not exclude a considerable magnesium deficiency, which is more sensitively determined by the magnesium tolerance test.

Adult↗
PubMed1996

Nausea and vomiting after laparoscopic surgery: a comparison of propofol and thiopentone/halothane anaesthesia.

Sixty ASA I and II patients scheduled for laparoscopic cholecystectomy or inguinal herniotomy were randomly assigned to one of two groups: Group one (n = 30): induction with thiopentone 4-6 mg kg-1, fentanyl 2 micrograms kg-1, pancuronium 0.03 mg kg-1, and succinylcholine 1 mg kg-1, maintainance with halothane (0.8-1.5%), and N2O in O2 (FiO2 = 0.33). Group two (n = 30): induction with propofol 2-3 mg kg-1, fentanyl 2 micrograms kg-1, pancuronium 0.03 mg kg-1, and succinylcholine 1 mg kg-1, maintainance with propofol 6-10 mg kg-1 h-1, and O2 in N2 (FiO2:0.33). Seven of the patients experienced nausea in each group with group one having higher emetic scores. Six patients in group one vomited compared to none in group two (P < 0.05). The overall incidence of emetic sequelae (nausea or vomiting) was 43% in group one and 23% in group two (P = 0.17). Patients with propofol anaesthesia had lower emetic scores and higher recovery scores compared with those after thiopentone/halothane anaesthesia.

Adult↗
PubMed1996

Pharmacokinetics of piritramide after an intravenous bolus in surgical patients.

BACKGROUND: Piritramide is a synthetic opioid analgesic which is commonly used for postoperative analgesia. It is structurally related to meperidine, exhibiting full mu-receptor agonism. Pharmacokinetic data of the drug have not been reported so far. METHODS: Plasma protein binding of piritramide was studied in vitro. The kinetics were examined after a single intravenous bolus (0.2 mg/kg) in 10 male patients aged 22-53 years undergoing elective minor surgery. Plasma and urine concentrations were determined by gas chromatography in samples drawn before and after the bolus. The concentration vs. time data were evaluated by nonlinear regression analysis, and the mean values and SD of the individual pharmacokinetic parameters were calculated. A three-compartment body model was fitted to the data. RESULTS: The volume of distribution at steady state was 4.7 (0.7)l/kg, systemic plasma clearance was 7.8 (1.5) (mean (SD)) ml/kg/min. Renal clearance of unchanged piritramide was negligible (0.13 (0.09) ml/kg/min). The terminal elimination half-life was 8.0 (1.4) h. In vitro, the free fraction in plasma of piritramide did not change over the therapeutic concentration range (5.5 (1.3)% at a pH of 7.35) but decreased considerably with pH within the physiological range. CONCLUSION: Since the elimination half-life of piritramide appears to exceed the duration of clinically effective analgesia observed during the treatment of acute pain, the dose of piritramide should be titrated carefully during long-term treatment to avoid accumulation that may lead to adverse effects.

Adult↗
PubMed1995

[The effect of an intracardiac left-right shunt on thermodilution measurements of cardiac output. An extracorporeal circulation model].

Thermodilution measurements of cardiac output (CO) by means of Swan-Ganz catheters, in a strict sense, represent pulmonary arterial blood flow (PBF). In principle, this is also true in the presence of intracardiac left-to-right shunts due to atrial or ventricular septal defects. However, early recirculation of indicator may give rise to serious methodological problems in these cases. We sought to determine the influence of intracardiac left-to-right shunts on different devices for thermodilution measurements of CO using an extra-corporeal flow model. METHODS. Blood flow was regulated by means of a centrifugal pump that at the same time enabled complete mixing of the indicator after injection (Fig. 1). Pulmonary and systemic parts of the circulation were simulated using two membrane oxygenators and a systemic-venous reservoir to delay systemic recirculation of indicator. Control measurements of PBF (Qp) and systemic (Qs) blood flow were performed by calibrated electromagnetic flow-meters (EMF). Blood temperature was kept constant using a heat exchanger without altering the indicator mass balance in the pulmonary circulation. Left-to-right shunt was varied at different systemic flow levels applying a Qp:Qs ratio ranging from 1:1 to 2.5:1. Thermodilution measurements of PBF were performed using two different thermodilution catheters that were connected to commercially available CO computers. Additionally, thermodilution curves were recorded on a microcomputer and analysed with custom-made software that enabled iterative regression analyses of the initial decay to determine that part of the downslope that best fits a mono-exponentially declining function. Extrapolation of the thermodilution curve was then based on the respective curve segment in order to eliminate indicator recirculation due to shunt flow. RESULTS. At moderate left-to-right shunts (Qp:Qs < 2:1) all thermodilution measurements showed close agreement with control measurements. At higher shunt flows (Qp:Qs > or = 2:1), however, conventional extrapolation procedures of CO computers considerably underestimated PBF (Fig. 2). This was particularly true when a slow-response thermistor catheter was used (Fig. 3). The reason for this underestimation of Qp was an overestimation of the area under curve because of inadequate mathematical elimination of indicator recirculation by standard truncation methods (Fig. 4). However, curve-alert messages of the commercially implemented software did not occur. A high level of agreement could be consistently obtained using a fast-response thermistor together with individual definition of extrapolation limits according to logarithmic regression analyses. DISCUSSION AND CONCLUSION. Under varying levels of left-to-right shunt, both the response time of thermodilution catheters and the algorithms for calculation of flow considerably influenced the validity of thermodilution measurements of PBF in an extracorporeal flow model. The use of computer-based regression analyses to define the optimal segment for monoexponential extrapolation could effectively eliminate indicator recirculation from the initial portion of the declining thermodilution curve and showed the closest agreement with EMF measurements of Qp. The quality of thermodilution curves with respect to recirculation peaks in the flow model was slightly better than in clinical routine. Nevertheless, the clinical applicability of the modified extrapolation algorithm could be illustrated during pulmonary thermodilution measurements in an exemplary patient with a ventricular septal defect (Fig. 5). PBF at extremely high shunt ratios, however, cannot be assessed by monoexponential extrapolation in principle (Fig. 6). Insufficient elimination of indicator recirculation resulted in flow values that closely resembled systemic rather than PBF. This finding is in accordance with a mathematical analysis of the underlying Steward-Hamilton equation if an infinite number of recirculations would be

Cardiac Output↗
PubMed1995

[Anesthesia with propanidid in a liposomal preparation. An experimental study in swine].

BACKGROUND: Propanidid was widely used as a short-acting i.v. anaesthetic until it was withdrawn due to severe haemodynamic side effects. It was presumed that anaphylactoid reactions with massive histamine release were caused by the solvent cremophor rather than by propanidid itself. A new liposomal preparation of propanidid was examined in this animal study and compared with propanidid in cremophor solution and with propofol. METHODS: Eighteen pigs were randomly assigned to one of the following groups: Group 1 (n = 6): Propanidid in liposomal preparation (PropaLip; Braun Melsungen, Germany). Anaesthesia was induced with 60 mg/kg, followed by continuous infusion of 400 mg/kg.h. Group 2 (n = 6): Propanidid in cremophor solution (PropaCrem; Sombrevin, Gedeon Richter, Budapest) 15 mg/kg, 100 mg/kg.h. Group 3 (n = 6): Propofol (Disoprivan, Zeneca, Plankstadt, Germany) 5 mg/kg, 20 mg/kg.h. After induction and tracheal intubation, the animals were ventilated with 50% oxygen in air. Basic monitoring included noninvasive blood pressure measurements, electrocardiographic monitoring, and capnography. In a short surgical procedure, arterial and pulmonary artery catheters were placed via the right carotid artery and right internal jugular vein, respectively. As soon as the animals responded to a pain stimulus a second anaesthetic induction was performed, followed by a 60-min continuous infusion of the agent studied with invasive haemodynamic monitoring including arterial and pulmonary arterial pressures and cardiac output. Blood samples were taken for the measurement of serum levels of adrenaline, noradrenaline, cortisol, aldosterone, adrenocorticotropic hormone, and histamine. RESULTS: Intubation conditions and quality of anaesthesia were best in propofol animals, followed by PropaCrem animals. In spite of the large dose of 410 mg/kg.h, resulting in a volume load of as much as 16.4 ml/kg.h, the PropaLip animals showed evidence of poor anaesthetic quality. In group 1 we recorded the highest increases in heart rate (91 vs. 115/min), cardiac output (5.4 vs. 7.7 l/min), plasma catecholamine levels, and histamine concentrations (124-268 ng/ml). CONCLUSIONS: In our animal study, propanidid in liposomal preparation failed to show promise as a new anaesthetic agent. Our results are discussed in view of a drug targeting the cells of the reticuloendothelial system, especially the liver, where liposomes are eliminated from the blood. This may result in the transport of propanidid to one of its major places of inactivation.

Anesthesia, Intravenous↗
PubMed1995

Transpulmonary disposition of prilocaine, mepivacaine, and bupivacaine in humans in the course of epidural anaesthesia.

The pulmonary first-pass kinetics of the amide-linked local anaesthetics prilocaine, mepivacaine and bupivacaine were studied in 33 patients after a single epidural injection. Drug concentrations were monitored before and after lung passage, i.e. in samples withdrawn simultaneously from mixed venous and arterial blood. In most cases, maximum plasma concentrations were observed 10 min after injection (range 2 to 30 min). Two min after injection the local anaesthetics were distinctly extracted by the lung (prilocaine 40%, mepivacaine 20%, and bupivacaine 12%). Prilocaine was retained by the lung more effectively than bupivacaine and mepivacaine. However, a transpulmonary concentration gradient could be observed only for a short time, i.e. maximum 15 min. Altogether, in the case of accidental fast absorption, e.g. inadvertent intravenous injection, arterial peak concentrations of these drugs will be attenuated by passage of the lung. However, the lung will not substantially lower the risk of toxicity by amide-linked local anaesthetics during normal conditions of regional anaesthesia where slow absorption occurs.

Adult↗
PubMed1995

[Theoretical limits of "permissive anemia"].

The limiting factor for acute anemia is myocardial oxygen supply, since arterial oxygen content is decreased by isovolemic hemodilution while myocardial oxygen demand is increased as a result of a compensatory increase of cardiac output. A theoretical model was developed which describes the relation between hematocrit, myocardial oxygen demand and the required coronary blood flow during progressive hemodilution. Using this model, the determinants of critical hematocrit and the limits of intentional acute anemia (= "permissive anemia") can be calculated based on the limits of coronary vasodilator reserve. For a normal systemic oxygen consumption of 120 ml min-1 m-2 a critical degree of hemodilution is achieved at an hematocrit of 14% and an hemoglobin content of 4.7 g dl-1, respectively. Hyperoxia with an arterial pO2 of 400 mmHg will shift the critical hematocrit to 12%. An increase of systemic oxygen consumption by a factor of three (460 ml min-1 m-2), which might be typical for a patient during the postoperative recovery phase, increases the critical hematocrit to 21%. In patients with coronary artery disease critical hematocrit levels might be much higher. We conclude that a fixed critical hematocrit as a transfusion trigger is not appropriate in most patients. Rather the indication for blood transfusions must individually appreciate the specific circumstances of the patient, such as expected blood loss and required oxygen transport capacity reserves, hemodynamic stability, coronary artery disease and systemic oxygen consumption. It is suggested that the model presented herein might be valuable for estimation of the individual critical hematocrit in a particular patient.

Anesthesia Recovery Period↗
PubMed1995

[Interactions between renal and general hemodynamics in fentanyl, droperidol, ketamine, thiopental and in peridural anesthesia--animal studies].

The main focus of this paper is to show regulative interactions between cardiac index (CI) and renal blood flow (RBF) with various intravenous anaesthetics under steady state conditions. Several experimental series were carried out on dogs with the following anaesthetic doses (as given per hour and per kilogram body weight-h-1 x kg-1): fentanyl 50 micrograms, ketamine 4 and 10 mg, and thiopentone 10 and 20 mg. The basic anaesthesia used was halothane (0.7 vol.%) in N2O/O2 (ratio about 3:1), because renal function, renal autoregulation and responsiveness to renally effective drugs remain nearly unaltered by this anaesthetic procedure. The experimental set-up allowed separate evaluation of effects caused by basic anaesthesia, by intravenous anaesthetic under examination or by the combination of both. All physiological parameters, such as blood gas parameters, plasma electrolytes and intravasal volume were kept in normal range throughout the experiments. Under all anaesthetics studied, RBF reflects the situation of general metabolism especially of cardiac output, as long as sympathetic innervation of the kidneys remains unaltered. Especially the relationship between RBF and CI corresponds with regulative effects in situations without anaesthesia. Within the blood pressure range of autoregulation RBF is greater under ketamine than normal and smaller under fentanyl and etomidate, whereas all other anaesthetics applied show no effect on RBF. Functional "denervation" of the kidney by means of epidural anaesthesia is capable of terminating those effects caused centrally by opioids and transmitted by sympathetic nerves. Diuresis is increased by thiopentone and by ketamine, whereas fentanyl reduces it. The activity of the plasma renin level does not correspond with the degree of renal vascular resistance. The effect of each anaesthetic drug on RBF has principally to be taken as regulative adaptation to altered circulatory conditions. Increasing plasma renin levels are mainly a compensatory reaction following a decline in arterial blood pressure due to anaesthesia induced sympathicolysis. With regard to renal function, the additional use of epidural anaesthesia (functional "denervation" of the kidney) can be recommended especially for highly invasive surgical procedures to antagonize reduction of RBF, which is often induced sympathetically by pain or by commonly used anaesthetic drugs.

Anesthesia, Epidural↗
PubMed1994

[Initial defibrillation by emergency physicians or by first aid assistants? A prospective, comparative multicenter study in outpatients with ventricular fibrillation].

In a controlled prospective randomized study, defibrillation by emergency medical technicians (EMTs) was compared with the current standard of care in Germany (basic life support by EMTs and defibrillation by emergency physicians only) in order to answer the following questions: 1. Does EMT defibrillation improve the survival rate and long-term prognosis of patients in ventricular fibrillation as compared to the current German standards in resuscitation (basic life support by EMTs and defibrillation by emergency physicians)? 2. Are the prerequisites for the use of semiautomatic defibrillators fulfilled in the emergency medical systems (EMS) of the participating centers? METHODS. The study phase includes randomization of 121 adult patients with witnessed cardiac arrest and ventricular fibrillation (VF) as first ECG rhythm. Prior to the onset of the study, all EMTs of the participating EMS systems were retrained in basic life support (BLS) measures. In each center, randomly assessed EMT-Ds (EMTs trained in Defibrillation) were trained to use semiautomatic defibrillators. With the help of one-line tape recording, the time intervals during resuscitation and treatment steps were evaluated. Successfully resuscitated patients were followed up with the help of the Glasgow Coma Scale and the Pittsburgh Cerebral and Overall Performance Categories. RESULTS. From 1 February 1991 until 28 June 1992, 159 patients with VF were randomized. In 121 cases, collapse was witnessed. 25% (14/57) of the patients receiving defibrillation by EMT-Ds (study group = S) were discharged from the hospital alive. In the control group, 52 patients were defibrillated by emergency physicians, following BLS by EMTs [control group 1 = C1; discharged: 29% (15/52)]. Fifty patients received BLS and advanced cardiac life support (ACLS) by the emergency physicians crews [control group 2 = C2; discharged: 18% (9/20)]. In the study group, the median time interval from collapse of the patient until initiation of BLS measures was 7.7 min, 7 min in C1 and 8 min in C2. ACLS measures were initiated significantly earlier (P < 0.05) in the control groups, as compared to the study group [S: 13 min, C1: 11 min; C2: 10.3 min]. Sixty-seven percent (30/45) of the study patients and 46% (36/76) of the control patients were defibrillated within 12 min. Study patients were defibrillated earlier (P < 0.05) (S: 9.9 min; C1: 12.2 min; C2: 12.75 min); return of spontaneous circulation (ROSC) was achieved earlier (P < 0.05) in the study group [S: 14 min; C1: 19 min; C2: 18.2 min] and the number of patients in the study group requiring no epinephrine during resuscitation was higher (P < 0.01) than in the control groups [S: 35.3% (12/34); C1: 10% (4/40); C2: 10.5% (4/38)]. Furthermore, the total amount of epinephrine [mean (+/- standard error)] administered in the study group [S: 2.35 (+/- 0.49) mg; C1: 6.71 (+/- 0.98) mg; C2: 7.71 (+/- 1.31) mg] was significantly lower (P < 0.05). No significant differences in neurological long-term prognosis were found for the groups investigated. CONCLUSION. Neither the initial survival rate the number of patients discharged alive, nor the neurological long-term prognosis was significantly different for any of the groups investigated. Because of apparent differences in indirect prognostic parameters (time interval until ROSC, number of patients requiring no epinephrine) and because of the fact that the time interval to the first defibrillation was reduced by EMT defibrillation, EMT-Ds may perform defibrillation if: (a) they reach the patient before the emergency physician and (b) if they are trained intensively and supervised continuously. In order to increase the efficiency of defibrillation by EMT-Ds, far-reaching changes in our EMS are mandatory: (a) a reduction in the time interval from collapse until initiation of BCLS measures by intensifying layperson CPR training; (b) an increase in the number of emergency units equipped with semiautomatic defibril

Electric Countershock↗
PubMed1994

[Total intravenous anesthesia with methohexital-alfentanil or propofol-alfentanil in hypogastric laparotomy. Clinical aspects and the effects of stress reaction].

Total intravenous anaesthesia (TIVA) using a combination of a hypnotic and an analgesic agent is gaining increasing popularity as an alternative to balanced anaesthesia with volatile anaesthetics for abdominal surgery. Among the required characteristics of the drugs used in this technique are a good correlation between dose, plasma concentrations, and effect as well as rapid elimination from the circulation, allowing close control of anaesthetic depth. Two hypnotic drugs with similar pharmacokinetic and pharmacodynamic profiles are propofol and methohexitone, both of which can be employed as a component of a TIVA technique. Two TIVA combinations utilising either of these drugs with alfentanil were tested against isoflurane-nitrous oxide in a balanced regimen. METHODS. Twenty-seven healthy women undergoing hysterectomy for non-malignant diseases participated in the study after having given written consent. They were randomly allocated to receive either isoflurane (Iso), methohexital-alfentanil (M-A), or propofol-alfentanil (P-A). Blood samples for determination of cortisol, prolactin, catecholamines, glucose, lactate, non-esterified fatty acids, and pharmacon concentrations were drawn repeatedly from before induction until 360 min after surgery. Anaesthesia was induced in group Iso with fentanyl 0.1 mg and M 1.5 mg.kg-1 and maintained with Iso-N2O. In the TIVA groups M or P was given in a two-step infusion to load peripheral compartments and then maintain plasma concentrations within the hypnotic range. A was given as a continuous infusion in an identical dose (0.1 mg.kg-1 initial, 0.125 mg.kg-1.h-1 maintenance) in both groups. If signs of insufficient depth of anaesthesia occurred (heart rate or systolic blood pressure > 25% above baseline), then first A (0.5-1 mg), and if that was ineffective, then 50 mg hypnotic was administered. The A infusion was stopped 30 min before the end of surgery, and Iso or the hypnotic was stopped at skin closure. Recovery time was the time until the patients were able to give their birth date after stopping the Iso or hypnotic. RESULTS. The three groups were comparable with regard to age, weight, and duration of surgery. The total doses of M and P were 1,357 +/- 125 mg (mean +/- SEM) and 1,315 +/- 121 mg, respectively, and the total A doses were 20.7 +/- 2.5 mg (M-A) and 23.4 +/- 3.5 (P-A). The peak plasma concentrations were P 10.6 +/- 1.5 micrograms.ml-1 and M 12.4 +/- 2.6 micrograms.ml-1. At the end of surgery the P concentrations were in the projected range while those of M were somewhat lower than expected (P 3.7 +/- 0.4 microgram.ml-1; M 3.5 +/- 0.6 microgram.ml-1). Three patients each in the P-A and M-A groups required supplementary A injections. Five patients in the P-A group required additional bolus injections of the hypnotic as compared to 2 in the M-A group. The median recovery times were Iso 15 min, M-A 50 min, and P-A 25 min (P < 0.05). The incidence of shivering was Iso 3/9, M-A 5/9, and P-A 0/9 (P < 0.05); vomiting occurred with equal frequency in all groups (Iso 33%, M-A 33%, P-A 22%). The patients were somewhat more restless in group M-A. Systolic blood pressure dropped in a similar manner in all groups after induction of anaesthesia (Iso -31%, M-A -37%, P-A -36%) but recovered during surgery. The intraoperative response of cortisol (Iso + 216%, M-A +92%, P-A +43%) and catecholamines (noradrenaline Iso +56%, M-A +30%, P-A -21%) was lower in the TIVA groups, whereas prolactin increased after induction in all groups. Plasma concentrations of glucose, lactate, and fatty acids were lower in the TIVA groups than in the Iso group intraoperatively, but increased to comparable postoperative levels. CONCLUSIONS. Both TIVA regimens are acceptable alternatives to balanced anaesthesia with Iso N2O. (ABSTRACT TRUNCATED)

Adult↗