Biomedical subjects
Publications and source records attributed to W Krumholz.
The influence of clinically relevant concentrations of fentanyl, alfentanil, morphine, pethidine, and buprenorphine on polymorphonuclear neutrophilic granulocyte (PMN) adherence was investigated in vitro by using nylon fibre columns. Since none of the drugs produced any significant (p less than 0.05) change of adherence, no evidence of opioid mediated increased risk of postoperative bacterial infection could be found.
The influence of clinically relevant concentrations of thiopentone sodium, methohexitone, and etomidate on polymorphonuclear neutrophilic granulocyte (PMN) adherence was investigated in vitro by using nylon fibre columns. The three induction agents produced dose-dependently a significant (p less than 0.01) reduction in adherence. This effect is possibly related to increased risk of postoperative bacterial infection. Further studies on this problem are recommended.
Pharmacokinetics of mezlocillin (70 mg/kg as an infusion) were investigated in 8 patients with multiorgan failure undergoing continuous veno-venous haemofiltration (CVVH) due to acute renal failure (HF-group) in comparison to 8 intensive care patients with an uneffected renal system (control group). Mezlocillin concentration were studied in blood, ultrafiltrate and urine (control group). Elimination of mezlocillin was prolonged in the HF-group with a t1/2 of 170 min in comparison to 109 min in the control patients. No relevant absorption at the haemofilter membrane could be observed. With regard to our results a dose reduction and intermittend application of mezlocillin is suggested; in addition, monitoring of drug levels in critically ill patients becomes of increasing interest, especially during haemofiltration.
Infection is still an important problem following surgery. Polymorphonuclear neutrophil granulocytes (PMN) play a vital role in host defenses against invading bacteria; thus, adverse effects on PMN caused by anesthetic agents are of general interest. In this study, we examined the influence of pancuronium bromide on PMN adherence in vitro. Heparinized venous blood samples were obtained from 18 healthy male adult donors. Each specimen was divided. One part was used to determine the adherence of untreated PMN, while pancuronium bromide was added to the other. Two concentrations (1.3 or 0.5 micrograms relaxant/ml blood) were tested. PMN adherence was studied using nylon fiber columns as described by MacGregor et al. Both concentrations of pancuronium bromide caused an inhibition of adherence, which was significant in the case of the higher dosage (p less than 0.05). There is a direct correlation between the intensity of PMN adherence and the extent of granulocyte delivery to sites of inflammation. Therefore, it seems possible that clinical concentrations of pancuronium bromide may be able to increase the risk of developing bacterial infections. Further studies concerning this problem should be conducted.
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The general opinion on epidural anesthesia in obstetrics may be adversely affected by recent public controversies about the mother's situation during childbirth in hospital, which nowadays is often considered to be a highly technological, impersonal, or "unnatural" procedure. This assumption led us to conduct an inquiry on maternal assessment of obstetric epidural anesthesia and its relation to the clinical and social history. The study included 113 parturients, who received epidural anesthesia (on-demand epidural injections of bupivacaine 0.25%) for vaginal delivery. Mothers were asked to answer certain questions about this regimen (e.g. analgetic efficacy; difficulties in deciding on this method; recommendations to other parturients; opinion of the role of epidural anesthesia in obstetrics; choice of analgesic regimen for future childbirth) 1 day after delivery and 2 months later. Additional social and historical factors (e.g. education; profession; family status; preceding pregnancy, childbirth or abortion; complications during pregnancy or childbirth; duration of parturition) were used to reveal relevant statistical correlations. Sixty-five percent of the patients considered pain relief by epidural anesthesia as "good" or even "very good" during the first inquiry immediately after childbirth. Women who had undergone prior interruptions of pregnancy were less satisfied, probably because of their rather ambiguous attitude towards motherhood. With regard to the choice of analgesic regimen for future childbirth (50% of the patients had made a definite decision to have epidural anesthesia under this condition), those women were especially reserved who had suffered from complications during pregnancy and disapproved of it in the future.(ABSTRACT TRUNCATED AT 250 WORDS)
The influence of midazolam and ketamine on polymorphonuclear neutrophil granulocyte (PMN) adherence was investigated in vitro by using nylon fiber columns. Both a concentration of 1.0 microgram midazolam/ml blood and 0.2 microgram/ml caused a reduction of adherence. This decrease was significant (p less than 0.05) in the case of the higher dosage. The two concentrations of ketamine used (1.3 micrograms/ml resp. 0.5 microgram/ml) produced a significant reduction of adherence too. Thus both anesthetic agents are able to impair PMN function in vitro dose-dependently. This feature is possibly related to increased risk of postoperative bacterial infection. Further studies concerning this problem should be conducted.
44 patients undergoing comparable gynaecological operations received either halothane- modified neuroleptanaesthesia or a combination of epidural and NLA. Monoclonal antibodies were used to determine 8 different lymphocyte subpopulations in blood samples drawn before and after anaesthesia and on the first postoperative day. Cell populations were counted by fluorescent microscopy. Halothane anaesthesia produced both a depression of T-cells (72.67% preoperatively to 52.79% postoperatively) and of the helper/suppressor ratio (1.46 to 1.10); meanwhile activated T-cells increased from 2.33% to 6.83%. After neuroleptanaesthesia as well as after halothane the HLA-DR positive cells decreased (21.05% to 19.29%; 25.22% to 20.29%). The B-cell fraction was elevated from 2.33% to 6.83% following combined anaesthesia. The potential of the anaesthetics to produce subsequent alterations in host defense is discussed.
Risk factors related to increased mortality were determined on the basis of 329 aortocoronary bypass operations. They were: (1) emergency surgery, (2) poor left ventricular function, (3) reoperation, and (4) pulmonary hypertension. Angina pectoris, recent myocardial infarction, age over 65 years, obesity, significant systemic disturbances, smoking, arterial hypertension, and sex were without effect.
In patients with cancer pain treated by continuous epidural opiate infusion (4.5-24 mg morphine per day) via implanted or portable pumps (n = 40) plasma levels of morphine were determined during the postoperative period and during regular refill of the pump systems. Concentrations were between 2.6 and 18.8 ng/ml depending on daily dosage and body weight. There were no signs of accumulation. Concentrations in lumbar CSF measured in some of the patients were 15-20 higher but decreased by 10-20% (in relation to daily dosage) in the course of long-term treatment. This may be induced by reduction in permeability of the dura due to fibrosis within the epidural space after chronicle catheterization. Cervical CSF concentrations (during chordotomy) were about 1/6 to 1/7 of the corresponding lumbar CSF levels. It may be assumed that epidural opiate infusion in spite of low blood levels is accompanied by relevant cerebral opiate actions.
Alfentanil mask anaesthesia was performed in 63 patients undergoing termination of pregnancy or curettage. Three different types of premedication were used: a) pethidine, promethazine, and atropine; b) diazepam and atropine; c) atropine. The patients were ventilated either with nitrous oxide and oxygen or with halothane and oxygen. Halothane reduced the frequency of muscular rigidity (32%; N2O 75%), postoperative sickness, and vomiting (23%; N2O 50%). On the other hand, patients regained consciousness earlier if nitrous oxide was used. Premedication a) also reduced the frequency of nausea and emesis (21%; other premedications 63%).-Alfentanil intubation anaesthesia was performed in 52 patients undergoing laparoscopy. Premedication and inhalation anaesthetic varied as described above in the group with mask anaesthesia. Muscular rigidity did not occur, and nausea/emesis were rare events (8%). Halothane prolonged the recovery phase of consciousness and respiration. Premedication a) also resulted in respiratory depression.
Spectral analysis with the compressed spectral array display (CSA) and calculation of spectral edge frequency (SEF) was performed in 43 cases undergoing endarterectomy of the carotid bifurcation. New neurologic deficit appeared in 2 patients (= 4.6%). One of them died postoperatively (= 2.3%), the other suffered from permanent paralysis of the hand. Another 9 patients showed loss of high frequency activity (= decrease in SEF) without a new deficit in the postoperative period. A significant EEG event was defined as a decrease in SEF after carotid cross clamping for at least 5 min. Fisher's exact probability test revealed a close correlation between these EEG events and neurologic outcome. The sensitivity of the test, which was calculated on true positive and false negative events, was 100%, the specificity, based on true negative and false positive events, was 76%. The predictability of the test, based on all EEG events, was 18%; respectively 40% when calculated on significant events.
Methodological considerations and different stimulation techniques of visual evoked potentials (VEP) are described. VEP can provide information about neurological function during anaesthesia, surgery and in the unconscious patient after head injury. The feasibility of the method for intraoperative monitoring in neuro- and cardiac surgery and the influence of general anaesthetics and other contributing factors such as temperature, paCO2, pO2, part are discussed.
A demand-controlled alfentanil bolus technique, which proved to be a safe and easy-to-handle method in 22 neurosurgical operations of mean and longer duration, is described. In the case of these not very painful procedures the use of more complicated time-controlled bolus or infusion techniques does not seem to be necessary.
After injection of etomidate during surgery for herniation of an intervertebral disk an anaphylactoid reaction occurred. Generalized erythema, severe urticaria, and rise in heart rate and blood pressure drop were observed. After treatment with an antihistaminic and a corticosteroid the phenomenons completely disappeared within 45 minutes.
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The prosthetic supply of the hip-joint may be accompanied by the problem of venous air embolism. By including 53 orthopaedic patients having undergone total hip replacement, the influence of bone-cement as well as of the different anaesthetic techniques on the frequency of embolic phenomenons was investigated. Embolism was determined as an abrupt decrease (greater than 5 mmHg) in the end-tidal pCO2. Venous embolism often occurred with cemented endoprostheses in contrast to non-cement implantations. Patients with general anaesthesia presented more often with venous air embolism than patients with epidural anaesthesia. This might be explained by an expanding effect of nitrous oxide on air bubbles entering the vascular bed under the implantation of the shaft-prostheses. Our data stress the importance of continuous monitoring of end-tidal pCO2 for early discovery of lung embolism.