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W Dick

Publications and source records attributed to W Dick.

At least 73 records · Page 4Linked to original sources

High dose naloxone does not improve cerebral or myocardial blood flow during cardiopulmonary resuscitation in pigs.

In a prospective, randomized, placebo-controlled, double-blind trial we tested the hypothesis that naloxone given during cardiopulmonary resuscitation (CPR) enhances cerebral and myocardial blood flow. Twenty-one anesthetized, normoventilated pigs were instrumented for measurements of right atrial and aortic pressures, and regional organ blood flow (radiolabeled microspheres). After 5 min of untreated fibrillatory arrest, CPR was commenced using a pneumatic chest compressor/ventilator. With onset of CPR, an i.v. bolus of 40 micrograms/kg b.w. of epinephrine was given, followed by an infusion of 0.4 micrograms/kg per min. After 5 min of CPR, either naloxone, 10 mg/kg b.w. (group N, n = 11) or normal saline (group S, n = 10) was given i.v. Prior to, and after 1, 15, and 30 min of CPR, hemodynamic and blood flow measurements were obtained. After 30 min of CPR, mean arterial pressure was significantly higher in group N (26 +/- 5 vs. 13 +/- 3 mmHg, P < 0.05). Groups did not differ with respect to myocardial perfusion pressure or arterial blood gases at any time during the observation period. Regional brain and heart blood flows were not different between N and S at any point of measurement. We conclude that high-dose naloxone does not augment cerebral or myocardial blood flow during prolonged closed-chest CPR.

Acid-Base Equilibrium↗

[Resistance to vecuronium--a case report].

We observed that a female patient aged 52 undergoing elective surgery (microscopic laryngoscopy and laser resection) was markedly resistant to the action of the neuromuscular blocking drug vecuronium. During induction of anaesthesia with propofol and alfentanil no effect of neuromuscular relaxation was observed even after a total dose of more than 0.15 mg/kg vecuronium. Accelerography was used for monitoring neuromuscular function. Only with small doses of succinylcholine was clinically sufficient relaxation achievable. The patient had no drugs or diseases with known interaction on neuromuscular blocking agents, but a suspected hypothyroidism could be the reason for the resistance.

Anesthesia, Intravenous↗

[Research and ethics in emergency medicine. Findings of a workshop].

Prerequisites for experimental study designs are extremely difficult to realise under prehospital emergency conditions. Results obtained in animal experiments always need validation with prehospital or in hospital patient studies. Investigations related to emergency medicine are, however, an ethical obligation on behalf of the patient. A retrospective analysis of the available literature should be considered a prerequisite for prospective randomised and controlled studies. Frequently, a pilot study or feasibility trial needs to precede the actual study. Informed consent must be obtained for all patient studies. However, under emergency conditions informed consent cannot always be obtained due to unconsciousness, etc. Nevertheless, the following principles should be observed: (a) randomised studies are essential, even in emergency medicine; (b) they are ethically acceptable if the treatment provided for the study group is at least equivalent to the therapy for the control group; (c) only these preconditions guarantee that the patient always receives treatment in accordance with the standard of treatment. If the patient is unconscious or otherwise unable to give informed consent, the principle of deferred consent is acceptable. The deferred consent principle should be carefully documented. A prospective randomized study represents the gold standard for an investigation, even under emergency conditions. There are different principles of randomization: telephone or telefax randomisation, etc. Emergency medicine investigations need to be completed within a reasonable time frame which should, as a rule, not exceed 2 years. Otherwise, too many items might change without being noted. Curative treatment and the intention to treat are terms employed by ethics committees. If an investigation does not bear in itself additional risk factors, it does not necessarily have to be brought before the ethics committee. If, however, for example, the effect of obtaining blood samples is investigated separately for research purposes, the patient needs to be informed and sign the respective agreement. In Germany the ethics committees have agreed to accept their respective decisions. For multicentre and multinational studies, however, the ethics committees also need to accept decisions made by non-German ethics committees. Not all therapeutic principles can serve as the basis of prospective randomized studies because they need to be considered the present standard of care (e.g., endotracheal intubation, etc.). Nevertheless, the feasibility of a study should be assessed according to the 1-3 rating proposed by the American Heart Association. In principle, the overall emergency physician protocol does not fulfill scientific requirements. For all studies, particularly in the prehospital setting, an independent observer should be involved for documentation purposes. Scores can be of importance for investigating different treatment regimens. Biases in emergency medicine studies focus on the variability of EMS, personnel qualifications, etc. This is in part why it is extremely difficult to prove efficacy and efficiency in emergency medicine. The results of emergency medicine investigations should be published in suitable journals, i.e., journals with a reasonable rating.

Emergency Medicine↗

[Routes for drug administration during cardiopulmonary resuscitation].

Selecting a route for drug administration during CPR requires consideration of the speed with which access can be obtained, the technical difficulties involved in performing the procedure, the associated risk of complications, delays in drug delivery to the central circulation, and the duration of effective drug levels following injection. The peripheral venous route is the safest method, and drug delivery can be enhanced by a fluid bolus after injection of the medication. The circulation time is shortest after central venous injection, but there is some risk of complications. The femoral route is associated with a high incidence of unsuccessful catherization. The endotracheal tube provides an accessible route for administration of most drugs, but peak concentrations are lower than those obtained by other routes. While the results are almost the same as an intravenous injection, the intraosseous route is currently underrepresented in clinical practice. This method must not only be considered in pediatric patients, but in adult patients as well.

Adult↗

Future directions for resuscitation research. III. External cardiopulmonary resuscitation advanced life support.

This discussion about advanced cardiac life support (ACLS) reflects disappointment with the over 50% of out-of-hospital cardiopulmonary resuscitation (CPR) attempts that fail to achieve restoration of spontaneous circulation (ROSC). Hospital discharge rates are equally poor for in-hospital CPR attempts outside special care units. Early bystander CPR and early defibrillation (manual, semi-automatic or automatic) are the most effective methods for achieving ROSC from ventricular fibrillation (VF). Automated external defibrillation (AED), which is effective in the hands of first responders in the out-of-hospital setting, should also be used and evaluated in hospitals, inside and outside of special care units. The first countershock is most important. Biphasic waveforms seem to have advantages over monophasic ones. Tracheal intubation has obvious efficacy when the airway is threatened. Scientific documentation of specific types, doses, and timing of drug treatments (epinephrine, bicarbonate, lidocaine, bretylium) are weak. Clinical trials have failed so far to document anything statistically but a breakthrough effect. Interactions between catecholamines and buffers need further exploration. A major cause of unsuccessful attempts at ROSC is the underlying disease, which present ACLS guidelines do not consider adequately. Early thrombolysis and early coronary revascularization procedures should also be considered for selected victims of sudden cardiac death. Emergency cardiopulmonary bypass (CPB) could be a breakthrough measure, but cannot be initiated rapidly enough in the field due to technical limitations. Open-chest CPR by ambulance physicians deserves further trials. In searches for causes of VF, neurocardiology gives clues for new directions. Fibrillation and defibrillation thresholds are influenced by the peripheral sympathetic and parasympathetic nervous systems and impulses from the frontal cerebral cortex. CPR for cardiac arrest of the mother in advanced pregnancy requires modifications and outcome data. Until more recognizable critical factors for ROSC are identified, titrated sequencing of ACLS measures, based on physiologic rationale and sound judgement, rather than rigid standards, gives the best chance for achieving survival with good cerebral function.

Animals↗

Active compression-decompression resuscitation: a prospective, randomized study in a two-tiered EMS system with physicians in the field.

Improved cardiopulmonary circulation with active compression-decompression cardiopulmonary resuscitation (ACD-CPR) has been demonstrated in studies using different animal models and a small number of humans in cardiac arrest (CA). However, prehospital studies have shown both positive and no extra benefit of ACD-CPR on return of spontaneous circulation (ROSC), hospital admission and discharge rates. The aim of our prospective study was to compare standard manual CPR (S-CPR) with ACD-CPR as the initial technique of resuscitating patients with out-of-hospital CA, with respect to survival rates and neurological outcome. Patients with out-of-hospital CA treated by emergency medical services (EMS) personnel were randomly assigned to one of two groups (ACD-CPR versus S-CPR). Time intervals to key measures were documented by means of on-line tape-recording. Neurological outcome was assessed using standard scoring systems (cerebral and overall performance categories (CPC and OPC)). A total of 220 patients (S-CPR, n = 114: ACD-CPR, n = 106) were included in the study in a random order. The treatment groups were similar with respect to age, sex, time interval from collapse to CPR, defibrillation and first adrenaline medication. There was no difference between the ACD group and the standard CPR group in terms of ROSC (50.9% vs. 59.6%), hospital admission (33% vs. 33.3%), hospital discharge (16% vs. 14%), or CPC and OPC (1.82 vs. 2.13 and 2.06 vs. 2.25, respectively). Concerning complications of CPR, there was no difference between the groups. In our two-tiered EMS system with physician-staffed ambulances, ACD-CPR neither improved nor impaired survival rates and neurological prognosis in patients with out-of-hospital cardiac arrest. The new CPR technique did not increase the complications associated with the resuscitation effort.

Cardiopulmonary Resuscitation↗

Cocaine or phenylephrine/lignocaine for nasal fibreoptic intubation?

In order to assess if a mixture of phenylephrine/lignocaine is as effective as cocaine for local analgesia and vasoconstriction during nasal fibreoptic intubation, 99 patients receiving topical nasal analgesia either with cocaine 10% or a mixture of phenylephrine 1% and lignocaine 4% were studied in a randomized double-blind investigation. After topical analgesia a flexible fibreoptic endoscope was advanced through a nostril. Larynx, glottis and trachea were endoscopically sprayed with lignocaine. Following induction of anaesthesia a nasotracheal tube was inserted fibreoptically. Pain intensity and amount of epistaxis during endoscopy were assessed. Blood pressure, heart rate and ECG-ST segment were determined before and after topical nasal analgesia, after induction of anaesthesia and after nasotracheal intubation. There were no significant differences in pain intensity of epistaxis between groups during endoscopy, nor significant alterations in haemodynamic parameters or ST-segment. It is concluded that the mixture of phenylephrine and lignocaine is a useful alternative to cocaine for local analgesia and vasoconstriction during nasal fibreoptic intubation.

Administration, Intranasal↗

Funding resuscitation research.

The present trend in managed care has meant downsizing expectations concerning the availability of support for resuscitation research. This trend applies to funding possibilities from industry, governmental agencies, and nongovernmental agencies (Table 1). There will be increasing barriers to making innovations. Truth, science, and good patient care alone will not make potential donors give grants. Investigators must also understand the potential donors' expectations and be persuasive. "Delight your donor". Industries' concerns include intellectual property rights and publications. The National Institutes of Health, recently favoring molecular biology over lifesaving therapies or integrated physiologic research, is an anomaly. The current peer review system propagates itself without having advocates for resuscitation research. This system has become a self-fulfilling prophecy. The American Heart Association is only recently, after 30 yrs of educational activities concerning cardiopulmonary resuscitation, considering putting some basic research money into resuscitation research. In university hospitals, where clinical departments have made significant contributions to innovative, clinically relevant life-support research, funded with incomes from patient care, the sky is beginning to fall. Resuscitation researchers need persuasive advocates with clout and hard data to convince funding agencies to give support to multilevel research and development in areas of pathophysiology and reversibility of terminal states and clinical death--to give these topics a higher priority than is currently available.

American Heart Association↗

[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↗

[Analgesia-sedation for maxillo-facial surgery with midazolam-pentazocine and miazolam-ketamine. Clinical double-blind study of anxiety, analgesia, sedation and amnesia].

UNLABELLED: Ketamine and midazolam, applied as intravenous medication for conscious sedation in day-case maxillo-facial surgery, has been proven to be superior to pentazocine and midazolam concerning cardiovascular parameters and respiratory depression. The aim of this study was to evaluate the effects of low-dose ketamine/midazolam on anxiety, analgesia, amnesia and subjective feelings. METHODS. 140 out-patients (ASA I) were randomly divided into four groups. The double-blind study was prospective. CONTROL GROUP: Local anaesthesia (LA), articaine 4% plus epinephrine 1:200,000 (n = 35); test group P/M: LA, additional pentazocine 0.40 mg/kg bw and midazolam 0.075 mg/kg bw i.v. (n = 35); test group K25/M: LA, additionally ketamine 0.25 mg/kg bw and midazolam 0.075 mg/kg bw i.v. (n = 35), test group K50/M: LA, additionally ketamine 0.5 mg/kg bw and midazolam 0.075 mg/kg bw i.v. (n = 35). LA was injected 3 min after application of the systemic medication in the test groups or application of a placebo (saline 0.9%) in the control group. Three further minutes later, operation was started. For evaluation questionnaires, visual analogue scales (VAS) and the state-trait anxiety inventory (STAI) were used. For testing retrograde and anterograde amnesia, acoustic sensations were delivered before application of the systemic medication (a Christmas carol) and during operation (the German national anthem). RESULTS. The control group and the test groups were comparable with regard to biological data, duration of operation, applied dosage of local anaesthetics and actual anxiety before operation. The patients in all test groups rated intraoperative anxiety as mild, in contrast to the control group. Nearly no pain sensation during the operation was remembered in all test groups. Retrograde amnesia was not found in any group. Complete anterograde amnesia was observed in all test groups with respect to the intraoperative sensation, but even in the control group 50% of the patients did not remember having heard the national anthem. As subjective feelings negative criteria were mainly reported in the control group, where as in all test groups positive sensations dominated. Dreams were reported mostly after the higher dosage of ketamine, but no patient experienced any unpleasant dreams. The clinical assessment of the different regimes were excellent for test groups P/M and K50/M, modest for the control group and test group K25/M. Postoperatively, patients of test group P/M were remarkably sedated, but no clinically relevant sedation or motor weakness were observed in the other groups. Postoperative pain sensations were rated more intense in all test groups than in the control group. In test groups P/M and K25/M an increasing pain level was recorded during the postoperative period, with the consequence of a higher demand rate for analgesics. CONCLUSIONS. Dental surgery can be performed safely with low-dose ketamine/midazolam. Compared to pentazocine/midazolam, the higher dosage of ketamine (0.5 mg/kg bw) showed identical results intraoperatively, but was superior during the postoperative period (vigilance), and thus may represent a suitable dosage. The lower dosage of ketamine resulted in worse operating conditions, but a dosage higher than 0.5 mg/kg bw might lead to unconscious sedation and might increase the frequency of unpleasant dreams.

Adjuvants, Anesthesia↗

Does standardized mega-code training improve the quality of pre-hospital advanced cardiac life support (ACLS)?

The aim of our prospective study was to evaluate the effects of a standardized mega-code and arrhythmia training upon process elements of quality of pre-hospital advanced cardiac life support provided by a physician-staffed mobile intensive care unit. In 145 cases of adult cardiac arrest due to cardiac aetiology, time intervals from arrival of the mobile intensive care unit at the patient's side until first ECG diagnosis, first defibrillation, endotracheal intubation, and first epinephrine administration were measured with on-line tape recording, prior to, and following a standardized 8-h arrhythmia and mega-code training. Following the training, patients with asystole or pulseless electrical activity were intubated 1.1 min earlier (P = 0.03), and received epinephrine 1.3 min earlier (P = 0.01) than prior to the training. There were no significant differences in time intervals concerning management of ventricular fibrillation or tachycardia. Neither admission nor discharge rates differed significantly before and after the training. Thus, practical training including rhythm analysis and mega-code session improved the performance of our mobile intensive care unit in cases of asystole and pulseless electrical activity, and, hence, process elements of quality.

Aged↗