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Biomedical subjects

W H Maleck

Publications and source records attributed to W H Maleck.

At least 55 records · Page 3Linked to original sources

[Prevention of postoperative nausea and vomiting after hysterectomy with oral dolasetron, intravenous dehydrobenzperidol or a combination of both substances].

OBJECTIVE: PONV is a frequent postoperative complication. The aim of this study was to assess the efficacy of oral dolasetron in comparison to intravenous droperidol (DHB) and to a combination of both drugs for prophylaxis of PONV. METHODS: 80 patients (ASA I-III) were randomly allocated to one of four groups and received the following medication: group A: 50 mg dolasetron was given orally 45-60 minutes before anaesthesia was induced, group B: 2.5 mg i.v. DHB + placebo p.o. was administered while inducing anaesthesia (positive control group), group C: 50 mg dolasetron was given 45-60 minutes before anaesthesia was induced and 2.5 mg i.v. DHB was given while inducing anaesthesia, group D: placebo tablet was administered 45-60 minutes before anaesthesia was induced (negative control group). PONV was assessed using a 5-point score: 0 = no symptoms, 1 = nausea, 2 = retching, 3 = vomiting, 4 = multiple vomiting. Metoclopramid was given as antiemetic if a patient reached two or more score points. RESULTS: PONV scores were significantly lower in group A and C (p < 0.001) compared to the control group. Patients treated with DHB showed a significantly lower PONV score in comparison to the placebo treated patients (p < 0.05). Between the groups A, B and C we found no significantly different PONV scores. Postoperative consumption of metoclopramid was significantly lower in the groups A (2.4 +/- 5.2 mg) and C (1.0 +/- 3.1 mg) than in the placebo group (6.0 +/- 6.8 mg), whereas between group B (3.0 +/- 5.7 mg) and D we found no significant differences. CONCLUSIONS: Single dose of oral dolasetron and single dose of intravenous DHB reduced PONV effectively, in patients undergoing gynaecologic surgery. A combination of dolasetron and DHB has no better effect than a single dose of oral dolasetron. Contrary to DHB the application of dolasetron decreased the postoperative antiemetic requirement significantly.

Antiemetics↗

Meconium and amniotic fluid embolism: effects on coagulation in pregnant mini-pigs.

OBJECTIVE: A hallmark of amniotic fluid embolism is the induction of coagulation defects. Little is known about the nature of these defects or the causative agent or agents. The purpose of this study was to assess the effects of meconium containing (native) meconium-amniotic-fluid infusion (MAFI) and meconium-free (centrifuged) amniotic-fluid infusion (AFI) on the coagulation system in the mini-pig model. DESIGN: Laboratory study. SETTING: University institute animal laboratory. SUBJECTS: Near-term pregnant Göttingen bred mini-pigs in three groups (control, MAFI, AFI) of six animals each. INTERVENTIONS: After induction of anesthesia, amniotic fluid was collected by cesarean section in all animals. Depending on the group, animals received either Ringer's solution (control), native amniotic fluid (MAFI), or centrifuged amniotic fluid (AFI) via an ear vein. MEASUREMENTS AND MAIN RESULTS: Blood samples were taken from a central vein before infusion (baseline), immediately after infusion, every 10 mins until 90 mins after infusion, and finally, every 20 mins until 150 mins after infusion. The following parameters were measured: Platelets, partial thromboplastin time, prothrombin time, fibrinogen, factors V, VII, VIII, antithrombin III, and protein C. The values relative to baseline in the MAFI and AFI groups were compared with control by rank order test. A p<.05 was considered statistically significant. Compared with the control group, platelets were lower in the MAFI group (p<.005), PTT was prolonged in both the MAFI and AFI groups (p<.005), fibrinogen was lower in both the MAFI and AFI groups (p<.05), prothrombin index was lower (i.e., prothrombin time was prolonged) in the MAFI group (p<.05), and protein C was lower in the MAFI group (p<.005). CONCLUSIONS: Both MAFI and, to a much lesser extent, AFI cause an activation of coagulation in mini-pigs. The changes induced by meconium-free AFI are probably not sufficient to explain the high mortality of the condition.

Amniotic Fluid↗

Another portable quantitative capnometer.

A new portable quantitative capnometer (Bruker CO2 Module) was tested in an animal lab (mini-pigs) during experiments on air embolism. The end-tidal CO2 values, as measured with this device, showed good agreement with the values of a stationary capnography unit. This device seems suited for quantitative capnometry in the prehospital setting.

Animals↗

Preliminary observations on the Colibri CO2-indicator.

The performance of a new colorimetric CO2-indicator (Colibri) was assessed in mini-pigs. It performed well during 8-hour procedures. Neither nitrous oxide, nor halothane, nor carbon monoxide, nor intratracheal application of drugs (epinephrine, atropine, lidocaine, and naloxone) interfered with its function. It gave a distinct color change at high ventilation frequencies up to 120/min. The only problem observed was difficulty in matching the colors displayed with the comparison color chart provided. The Colibri's performance seems at least equal to that of the EasyCAP detector, although both devices share some disadvantages (no alarms, semiquantitative, difficult reading in the dark). After initial control of endotracheal tube position by an esophageal detector device, both the Colibri and the EasyCAP seem suited for monitoring of ventilation and circulation if quantitative capnometry is unavailable.

Animals↗

[Prophylactic nefopam administration for post-anesthetic shivering].

PURPOSE: Shivering is a frequent postanaesthetic complication. Its definite reason is unknown. Patients with cardiovascular or pulmonary diseases are endangered by postanaesthetic shivering. The aim of this study was to assess the efficacy of nefopam in prophylaxis of shivering. Additionally we investigated the influence of nefopam on haemodynamic parameters and on the time until extubation. METHODS: 30 patients (ASA I-II) were randomly allocated in a double-blind fashion to one of two groups to receive directly after the end of isoflurane application either nefopam (0.15 mg/kg) or placebo (0.9% saline). The period of anaesthesia had to be longer than 60 minutes. All patients received a premedication with lorazepam (0.02 mg/kg) 30-45 minutes prior to surgery. Induction of anaesthesia was standardised: fentanyl (3 micrograms/kg), thiopentone (5 mg/kg), atracurium (0.4 mg/kg). Intraoperatively a mixture of isoflurane, nitrous oxide (60%) and oxygen was used to maintain anaesthesia. The following parameters were evaluated: Age, sex, duration of operation and anaesthesia and the time between the end of application of volatiles and extubation. Heart rate (HR), mean arterial blood pressure (MAP), rectal temperature and O2-saturation were measured at predefined data points. Postoperatively the consumption of analgesic was documented. The severity of shivering was classified in five grades. RESULTS: In the control-group nine patients shivered (60%), whereas in the nefopam group only one patient (6.6%) shivered (p < 0.05). In comparison to the placebo group we observed in the nefopam group a significantly decreased HR 30 and 60 minutes postoperatively (p < or = 0.007 and p < or = 0.002). We did not observe prolonged awakening in the nefopam-treated patients. MAP and O2-saturation showed similar reactions in both groups. CONCLUSION: The data indicate that prophylactic administration of nefopam can suppress postanaesthetic shivering. Prolonged awakening was not observed.

Analgesics, Non-Narcotic↗

[Bellows or bag? Testing 10 ventilators and some medical history comments].

We compared a new bellows ventilator (Kendall Cardiovent) with two other bellows (Dräger Resutator 63, Tagg Breathsaver) and seven bag or ball ventilators (Aerodyne Hope, Ambu Mark 3, Ambu Silicon, Dräger Resutator 2000, Laerdal Resu, Mercury CPR, Weinmann Combibag). Tidal volumes were measured with two Laerdal Recording Resusci Annies, one lying on the floor, one in a bed. Twelve participants performed mask ventilation with all ten devices on both manikins for two minutes, trying to achieve tidal volumes of between 0.8 and 1.21 as recommended by the AHA. The last ten ventilations each on the graphic strips were analysed for volume. The participants scored handling of the devices on a 6-point scale (1 = very good, 6 = insufficient). The results of the Cardiovent were compared to those of the other devices by rank sum test (percentage of correct ventilations) and sign test (subjective handling). The Cardiovent provided exact ventilation with 95% of ventilations) on the floor and 78% of ventilations in bed in the recommended range. However, the percentage of correct ventilations with the Cardiovent was not significantly different to the other devices except for a lower percentage of correct ventilations with the Combibag in the in bed setting. Concerning subjective handling, the Cardiovent was significantly superior to several ball ventilators.

Equipment Design↗

Myxoma complex associated with transient hyperthyroidism: are diseases of the thyroid part of the complex?

The myxoma complex is a very rare disease. We report on a 31-year-old woman who suffered a hyperthyreosis, which resolved spontaneously. A few months later she developed a Cushing's syndrome, caused by a primary adrenocortical nodular dysplasia. A bilateral adrenalectomy had to be performed. 15 months after this operation she developed a cerebral infarction caused by an embolus from a left atrial myxoma. Our patient is a further case of Carney's syndrome. The aspect of the hyperthyreosis is interesting: Perhaps disease of the thyroid represents a new element of Carney's syndrome.

Adult↗