Search PubMed⌕ Search

Biomedical subjects

W Ummenhofer

Publications and source records attributed to W Ummenhofer.

26 records · Page 2Linked to original sources
PubMed1994

Are laboratory values in bone marrow aspirate predictable for venous blood in paediatric patients?

In an emergency situation, early laboratory results are important, but often difficult to obtain. If venous access cannot be established, the intraosseous route may be used as an alternative. This study investigated the predictive value of bone marrow aspirate in performing laboratory studies. Thirty children underwent general anaesthesia for bone marrow aspiration (iliac crest) for oncologic or haematologic reasons. The aspirate and a peripheral venous blood sample, which was obtained simultaneously, were subjected to different laboratory tests and the results were compared by means of confidence interval analyses of the individual ratios of venous/bone marrow values. Based on these analyses, a high predictability of bone marrow values were found for haemoglobin, sodium, chloride, glucose, bilirubin, urea, creatinine, pH, and standard bicarbonate. Moderate, but clinically useful predictability was found for haematocrit, potassium, and total protein, while bone marrow values of alkaline phosphatase, aspartate aminotransferase, alanine aminotransferase, PCO2, PO2, thrombocytes and leukocytes were systematically different from values in venous blood. Our data suggest that the intraosseous route is not only an important emergency alternative to intravenous access for administering fluids and drugs but may also serve as a reliable alternative for obtaining initial diagnostic laboratory studies when intravascular access is not obtainable.

Analysis of Variance↗
PubMed1994

[Effect of halothane anesthesia on cerebral blood flow velocity in children].

The effects of halothane on the cerebral circulation were studied in 23 children during general anaesthesia. Blood flow velocity in one middle cerebral artery was recorded continuously by transcranial Doppler sonography. Furthermore arterial blood pressure, pulse rate, endtidal CO2partial pressure and endtidal halothane concentration were recorded. Mean flow velocities/mean arterial blood pressures were 79 cm x s-1/65 mmHg; 86 cm x s-1/61 mmHg; 78 cm x s-1/54 mmHg and 67 cm x s-1/48 mmHg with 1; 1.5; 2 and 2.5 per cent endtidal halothane concentrations, respectively. Endtidal CO2-partial pressure and pulse rate remained constant throughout the study. The higher cerebral blood flow velocities seen with 1.5 per cent halothane compared with 1 per cent can be explained by an increase in cerebral blood flow. The lower cerebral blood flow velocities and arterial blood pressure with 2.5 per cent halothane compared with 1.5 per cent indicate impaired cerebral autoregulation. However, cerebral blood flow appeared to be sufficient even with low arterial blood pressures.

Anesthesia, General↗
PubMed1994

Effects of ondansetron in the prevention of postoperative nausea and vomiting in children.

BACKGROUND: Postoperative nausea and vomiting (PONV) is a commonly observed adverse effect of general anesthesia. Recently, ondansetron, a new serotonin3 (5-hydroxytryptamine3) receptor antagonist was shown to be effective in the prophylaxis and prevention of chemotherapy-induced nausea and vomiting in children and adults as well as of PONV in adults. The aim of the current study was to evaluate the capacity of ondansetron to prevent PONV in pediatric patients. METHODS: Two hundred children (132 boys and 68 girls) 2-10 yr of age received general inhalational anesthesia for surgical procedures (the extremities; ear, nose, and throat; inguinal hernia and phimosis; and dentistry) of an expected duration of less than 90 min. This study was divided into two phases: prophylaxis and rescue treatment. For prophylaxis, patients were randomly assigned to two groups: one group received an intravenous injection of 0.1 mg/kg ondansetron, and the other group received a placebo before surgical incision under double-blind conditions. For rescue treatment, only placebo patients were included; as a rescue medication they received an intravenous injection of 0.1 mg/kg ondansetron or 0.02 mg/kg droperidol according to a prestudy randomization under double-blind conditions. Incidence and severity of PONV (PONV score 0 = no nausea and no retching; 1 = complaining of sickness and retching; 2 = vomiting one or two time in 30 min; 3 = vomiting more than two times in 30 min) was recorded over a 4-h period in the postanesthesia care unit. Within 72 h of the procedure, a follow-up nurse interviewed the parents for late-onset nausea in the children. RESULTS: With regard to prophylaxis, 10% of patients receiving ondansetron had PONV during the 4-h observation period versus 40% of those receiving placebo (P < 0.001). The incidence of vomiting alone (PONV score > or = 2) was 5% and 25%, respectively (P < 0.001). There were no significant differences between ondansetron and droperidol in the treatment of PONV. However, at the end of the 4-h period, ondansetron patients were less sedated than were patients who had received droperidol (P < 0.01). Interviews with parents could be performed for 143 of 200 children (76 ondansetron and 67 placebo). Twenty-four children (15 ondansetron and 9 placebo) showed late-onset PONV after the 4-h observation period but within 24 h of the procedure (19.7% vs. 13.4%; P not significant). CONCLUSIONS: Ondansetron is effective in the prevention of PONV in pediatric patients for the first 4 h after general anesthesia. Lower sedation scores with ondansetron compared with droperidol may be an advantage, especially in ambulatory surgery. However, the incidence of late-onset PONV (> 4-24 h) was not influenced by prophylactic treatment with one dose of ondansetron preoperatively.

Anesthesia, General↗
PubMed1993

Effects of laryngoscopy and tracheal intubation on cerebral and systemic haemodynamics in children under different protocols of anaesthesia.

The effects of laryngoscopy and tracheal intubation on cerebral and systemic haemodynamics were studied in 30 children. The objective was to identify conditions in which the alterations of cerebral and systemic haemodynamics were minimal. The children were intubated after muscular relaxation and following 10 min of mechanical ventilation with end-tidal halothane concentrations of 1.5%, 2.0% and 2.5%, respectively. With 1.5%, 2.0% and 2.5% end-tidal halothane, the mean flow velocity increased by 26%, 19% and 5%, the mean blood pressure by 14%, 10% and 1%, and the heart rate by 26%, 8% and 5% respectively after intubation. Adverse effects of laryngoscopy and tracheal intubation on cerebral haemodynamics in children can be avoided by adequate anaesthetic protocols.

Anesthesia, Inhalation↗
PubMed1979

[The effect of somatostatin on the ileocecal sphincter (ICS) before and after extensive small bowel resection].

The ileocoecal sphincter pressure of rabbits was studied under somatostatin infusion before and after subtotal small bowel resection. Before resection, somatostatin increased the pressure necessary to pass fluid through this zone according to the applied doses. Seven days after resection, a decrease in the ileocoecal sphincter pressure was found, which could not be affected by somatostatin infusion. One year after resection, the reflux pressure was again normal, and the somatostatin effect was similar as to that before resection.

Animals↗
PubMedDate not supplied

Hyperosmolarity does not contribute to transient radicular irritation after spinal anesthesia with hyperbaric 5% lidocaine.

BACKGROUND AND OBJECTIVES: In addition to major neurologic injury, local anesthesia toxicity may also include less severe but more common neurologic side effects. The authors recently observed symptoms suggestive of transient radicular irritation in one third of patients after spinal anesthesia with hyperbaric 5% lidocaine, whereas evidence of neurologic symptoms was lacking with hyperbaric 0.5% bupivacaine. The purpose of this prospective double-blinded study was to evaluate if the high osmolarity of hyperbaric 5% lidocaine solution might contribute to the development of transient radicular irritation. METHODS: Forty-four patients undergoing brief gynecologic procedures under spinal anesthesia were randomly allocated to receive 1.5 mL of one of three study drugs: 5% lidocaine in 7.5% dextrose (drug A), 0.5% bupivacaine in 8.25% dextrose (drug B), or 5% lidocaine in 2.7% dextrose (drug C). Drug C was prepared by the pharmacy (University Hospital, Basel, Switzerland) with an osmolarity similar to that of drug B. Drugs A and B were commercially available. Patients were evaluated on postoperative day 1 for symptoms of transient radicular irritation by an anesthesiologist who was unaware of the drug given or details of the anesthetic technique. RESULTS: Symptoms suggestive of transient radicular irritation were observed with a similar high incidence in patients receiving both lidocaine preparations, but in no patient receiving hyperbaric 0.5% bupivacaine (P < .01). CONCLUSIONS: The results suggest that transient radicular irritation did not result from the marked hyperosmolarity of the hyperbaric 5% lidocaine. However, because lidocaine and bupivacaine were not administered at equipotent dosages, the relative potential for both drugs to induce transient radicular irritation remains to be determined.

Adult↗