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Biomedical subjects

W R Waugaman

Publications and source records attributed to W R Waugaman.

At least 19 recordsLinked to original sources
PubMed1991

Anesthetic and hemodynamic effects of dexmedetomidine during isoflurane anesthesia in a canine model.

Dexmedetomidine, an alpha 2-adrenergic agonist, was administered during isoflurane anesthesia to investigate its anesthetic sparing and hemodynamic effects in the canine model. Eleven healthy dogs were anesthetized with isoflurane, intubated, and allowed to breathe spontaneously. The animals were instrumented in order to measure or calculate mean arterial blood pressure (MABP), heart rate (HR), left ventricular end diastolic pressure (LVEDP), cardiac output (CO), and systemic vascular resistance (SVR). Isoflurane minimum alveolar concentration (MAC), baseline hemodynamic measurements, and plasma catecholamine levels were determined. A 20 micrograms/kg bolus of dexmedetomidine was injected intravenously (IV) and MAC and hemodynamic values were redetermined. When isoflurane requirements were 33% of baseline, isoflurane was returned to 90% MAC and the alpha 2-antagonist, atipamezole, was administered. All dogs were treated with 40 micrograms/kg glycopyrrolate throughout the experiment to prevent any bradycardic response. Dexmedetomidine reduced isoflurane MAC by 86%. SVR, MABP, and LVEDP were significantly increased while CO and catechloamine levels were reduced. Atipamezole fully reversed the reduction in anesthetic requirements. MABP and catecholamine levels returned to baseline. SVR and LVEDP increased while CO decreased. The dogs exhibited a profound reduction in anesthetic requirement, reduced catecholamine levels, and changes in hemodynamic parameters with dexmedetomidine administration. The anesthetic sparing effect appears to be mediated by the alpha 2-receptor, since atipamezole reversed the reduction in MAC. Hemodynamic changes may be species or dose related, or due to differences in existing sympathetic tone. The role of dexmedetomidine warrants further study as an adjunct anesthetic agent.

Adrenergic alpha-Agonists↗
PubMed1991

Does the administration of oral Bicitra before elective cesarean section affect the incidence of nausea and vomiting in the parturient?

Soluble oral antacids are commonly used before anesthesia for cesarean section. The purpose of this prospective, single institution, randomized experimental study was to examine the relationship of oral administration of Bicitra (sodium citrate and citric acid) to the incidence of nausea and vomiting in patients undergoing elective cesarean section utilizing regional anesthesia, and to evaluate its effectiveness in neutralizing gastric acid. Eighty-six patients were studied (39 in a control group and 47 in a Bicitra treatment group) to ascertain if there was any difference with regard to height, weight, parity, gravity, age, race, incidence of heartburn with pregnancy, incidence of nausea with pregnancy, length of NPO status, preoperative systolic blood pressure (SBP), perioperative low level of SBP, and cumulative drop in SBP. Pearson chi square analysis showed no significant difference between the two groups for all variables or the incidence of nausea and vomiting. No significant difference was noted in the mean pH and volume of emesis of seven subjects analyzed using pooled t tests. After initial hypothesis testing was concluded, the sample was divided into two groups, those who experienced nausea and those who were free from nausea. The nausea group demonstrated a significantly greater cumulative decrease in SBP than did the non-nausea group. Larger patients (mean cube root weight index of 2.78) tended to become nauseated more frequently.

Administration, Oral↗
PubMed1991

Why publish?

The following article encourages student nurse anesthetists to publish knowledge learned from clinical and educational experiences; however, the same philosophy and advice applies to all nurse anesthetists. Dr. Waugaman presented the information in this article to more than 700 students who attended a Student Luncheon on August 6. The luncheon was among many special activities held for students during the 58th AANA Annual Meeting in Nashville, August 3-8, 1991. For more information on submitting manuscripts to the AANA Journal, please refer to "Information for Authors," published in each issue of the AANA Journal, and the February 1991 article titled "A style change for the AANA Journal," authored by Michael A. Fiedler, CRNA, MS, and E. Jane McCarthy, CRNA, PhD.

Nurse Anesthetists↗
PubMed1991

New advances in anesthesia.

Pharmacologic advances in anesthesia over the last decade have focused on drug safety, shorter durations of action, reversibility, and ease of administration. This is reflective of major changes in the focus of patient care from inpatient to outpatient settings as well as from available risk management data that support the investigation of these new drugs. The pharmacologic advances discussed included those drugs in current practice as well as experimental drugs yet to be released for general clinical use. Inhaled agents, such as isoflurane and perhaps the experimental agent, desflurane, will maintain or achieve their popularity because of the relative ease of administration and wide margins of safety. Propofol, the most recent intravenous anesthetic available for clinical use, has already gained wide acceptance because of its dual function as an induction and maintenance agent and its appropriateness for use in the ambulatory surgical population. The role of midazolam in anesthesia practice has increased to such an extent that it has largely supplanted the use of diazepam (Valium). The introduction of the antagonist, flumazenil, will undoubtedly enhance the safety and efficacy of midazolam as well as broaden its applicability of use across various patient populations. Several of the newer synthetic narcotics, such as alfentanil and sufentanil, have replaced other narcotics formerly used in anesthesia practice, such as meperidine and morphine, primarily because of their short action and lack of significant side effects. The use of muscle relaxants as a critical component of anesthetic management has led to the development of a number of new drugs in this classification. Pharmacologic management of patients under anesthesia will at some future date likely include the administration of alpha 2 agonists. Administration of these drugs can reduce anesthetic requirements of traditional agents by as much as 50%. As research continues, new drugs will be incorporated into the practice of anesthesia, ones that will promote rapid uptake, low toxicity, intense analgesia, easy reversibility, shorter durations, and fewer side effects. One measure of success relative to pharmacologic development in anesthesia is the recent and dramatic decreases in patient morbidity and mortality figures over the last decade. This attests to the rapid growth and development of not only improved patient monitoring systems but also newly improved "agents of sleep."

Anesthesia↗
PubMed1990

The effect of total parenteral nutrition and morphine on ventilation.

Total parenteral nutrition (TPN), specifically amino acid infusions, has been shown to increase the ventilatory response to inhaled CO2. The hypothesis tested was that morphine sulfate (known to depress ventilatory CO2 responsiveness) would diminish the augmented ventilatory CO2 response in patients receiving TPN. The influence of morphine on hyperoxic hypercapnic ventilatory response (assessed by the Read rebreathing technique) was therefore examined in four otherwise healthy subjects who were receiving TPN at home for long-standing nutritional support secondary to malabsorption syndrome (short-bowel syndrome), and in a control group of four healthy subjects who were not receiving TPN. The slope and intercept of the CO2 response was estimated by linear regression on the relationship between ventilation (VE) and end-tidal PCO2 (PETCO2). Administration of morphine in the non-TPN group elicited the expected decrease in the VE-PETCO2 slope. In contrast, morphine administration was associated with an increase in the VE-PETCO2 slope in the TPN group. While this investigation does not provide a direct indication of the mechanisms underlying the augmenting action of morphine on the ventilatory response to CO2 in subjects receiving TPN, it does suggest that patients on TPN who demonstrate no impairment of ventilatory control may be given normal doses of morphine sulphate (ie, as for pain control or preoperative medication) with no increased concern for an adverse ventilatory outcome.

Adult↗
PubMed1990

Does the employed technique of endotracheal extubation reduce the risk of aspiration?

Aspiration of gastric contents continues to be one of the most serious complications of general anesthesia. Laryngeal competence may be reduced immediately following endotracheal extubation, which may increase the risk of aspiration. An evaluation research design was used in 20 adult canines to compare the techniques of positive pressure extubation and extubation at the height of inspiration employing radiopaque barium. Evaluation of radiographs from both groups revealed that no aspirate of barium was detected in the tracheobronchial trees of any of the dogs. This study establishes that there is no difference in the risk of aspiration following endotracheal extubation using the canine model regardless of the clinical technique employed.

Animals↗