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Biomedical subjects

A Forrest

Publications and source records attributed to A Forrest.

At least 109 records · Page 6Linked to original sources

Weight-based heparin dosing: clinical response and resource utilization.

The objective of this study was to assess a weight-based heparin (WBH) nomogram (80-U/kg bolus, 18-U/kg-per-hour initial infusion) and determine its clinical performance and impact on resource utilization. All patients treated with heparin for venous thromboembolism or unstable angina during a 15-week study period were included in this retrospective, chart-review study. Three groups were identified: patients treated with WBH, patients whose regimen deviated from the weight-based nomogram (DEV), and matched historical controls (HCs). In patients receiving heparin for more than 24 hours, those treated with WBH achieved threshold activated partial thromboplastin time (aPTT) levels significantly faster than did HC or DEV patients. However, 42% of WBH-treated patients were found to have initial supratherapeutic responses. Logistic regression analysis identified age > or =67 years, prior warfarin therapy within 7 days of heparin, and high initial infusion rate as predictive of a supratherapeutic aPTT response; smoking was predictive of a subtherapeutic response. Bleeding events were not significantly different between groups. An infusion rate of 15 U/kg per hour was found to closely approximate our population's actual heparin infusion requirement. Resource utilization was significantly different between the WBH and HC groups in terms of nursing interventions at 48 to 72 hours. We concluded that WBH rapidly drives patients' aPTT response above the therapeutic threshold for heparin; however, prudent adjustment of the initial infusion rate is necessary to avoid a supratherapeutic aPTT response. Our data support a nomogram with an initial infusion rate of 15 U/kg per hour.

Adult↗

Normalization of hypertensive responses during ambulatory surgical stress by perioperative music.

OBJECTIVE: The purpose of this study was to determine whether cognitive appraisals of stress level and hypertensive responses to ambulatory ophthalmic surgery can be ameliorated by patient-selected music. METHODS: We studied 40 elderly individuals requiring ophthalmic surgery, 20 in an experimental group (mean age, 74 years) and 20 in a control group (mean age, 77 years). All patients had an established resting blood pressure <140/90 mm Hg. In the experimental group self-selected music was provided by headphones throughout the preoperative, surgical, and postoperative periods. In the control group patients had neither headphones nor music. All patients received similar (weight-determined) doses of alfentanil and midazolam during surgery. Heart rate, blood pressure, and patient-reported stress and coping levels were the dependent variables. RESULTS: In both groups, blood pressure values were normal (approximately 129/82 mm Hg) during screening examinations 1 week before surgery. On the day of surgery both groups displayed increased preoperative blood pressures (approximately 159/92 mm Hg) associated with increases in heart rate (by approximately 17 beats/min). Intraoperative blood pressures in the experimental group returned quickly to screening baseline values, whereas the control group experienced persistent elevations in intraoperative blood pressure similar to preoperative levels. Over the course of the surgical experience, patients with music reported significant reductions in perceived stress and increases in coping abilities (p < .001), whereas those without music did not. CONCLUSIONS: The perceived stress of ambulatory surgery in geriatric patients is associated with a clinical hypertensive response that is ameliorated by self-selected perioperative music, which also decreases perceived stress and increases patients' sense of personal control and well-being.

Acoustic Stimulation↗

Mathematical examination of dual individualization principles (II): The rate of bacterial eradication at the same area under the inhibitory curve is more rapid for ciprofloxacin than for cefmenoxime.

OBJECTIVE: To compare two antibiotics at equal ranges of area under the inhibitory curve (AUIC) exposure to determine if the rate of bacterial eradication differed between these antibiotics. DESIGN: Retrospective comparison of two previously collected studies of similar patients with nosocomial pneumonia. SETTING: Hospitalized patients, most intubated in critical care units with nosocomial pneumonia. PARTICIPANTS: Patients treated with either i.v. ciprofloxacin (n = 74) or the i.v. third-generation cephalosporin cefmenoxime (n = 43) were compared for their length of treatment required to eradicate bacterial pathogens from their respective infection sites, using serial cultures from the site of infection. All patients were also assessed for clinical outcomes. Serum samples were obtained to evaluate individual patient antibiotic pharmacokinetics, which were used to model pharmacodynamics of response. The HPLC assay used for each antibiotic had interday coefficients of variation < 10 percent. Serum concentration versus time profiles were fit using the computer program ADAPT II to determine pharmacokinetic parameters for each patient. The primary drug exposure measure that related to response was the AUIC, calculated as steady-state AUC0-24/minimum inhibitory concentration. RESULTS: AUIC values in the patients ranged from 6.0 to more than 7000, yet the AUIC value was highly predictive of time to bacterial eradication (p < 0.001). Although more than 75 percent of patients eventually achieved eradication of pathogens from tracheal aspirate cultures, ciprofloxacin and cefmenoxime differed significantly in the time required to sterilize these cultures. At appropriate AUIC values (> 250) for ciprofloxacin, the median time to eradication was two days, while cefmenoxime (also at AUIC values > 250) required six days to achieve the same result. CONCLUSIONS: We conclude that the more rapid in vitro bacterial killing, which is characteristic of ciprofloxacin at optimal AUIC values, can manifest in vivo as more rapid clearance of bacteria from the respiratory tract of patients, even when both agents are controlled for initial antibacterial exposure (i.e., same AUIC).

Anti-Bacterial Agents↗

Effects of the concomitant administration of tamsulosin (0.8 mg/day) on the pharmacokinetic and safety profile of theophylline (5 mg/kg): a placebo-controlled evaluation.

We performed a single-blind, sequential-design study to investigate the effects of concomitant oral tamsulosin 0.8 mg/day on the pharmacokinetics and safety of intravenous theophylline 5 mg/kg in healthy subjects. Ten healthy volunteers aged 19-39 years received placebo on study days 0, 1, 2 and 10 and tamsulosin on days 3-9. Theophylline was administered intravenously on days 1 and 9. Theophylline and tamsulosin pharmacokinetic data were determined following administration of the drugs on days 1 and 9 and day 9, respectively. No differences were observed in theophylline pharmacokinetic parameters with and without concomitant tamsulosin, and there were no abnormalities in tamsulosin pharmacokinetic data. Some significant changes in vital signs and a number of mild adverse reactions were reported, but the overall safety profile of tamsulosin and theophylline was acceptable. The results of the study suggest that no dose adjustment in tamsulosin is necessary when it is administered concomitantly with theophylline.

Administration, Oral↗

Working it out.

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Burnout, Professional↗

Predictors of trough concentrations of oral ciprofloxacin.

Patients enrolled in a fixed-dose clinical trial of oral ciprofloxacin had trough concentrations measured to document absorption and monitor compliance. The objective was to determine whether any demographic characteristics might be important predictors of the concentrations. Stepwise multivariate linear regression revealed no correlation between ciprofloxacin trough concentrations and serum creatinine, estimated creatinine clearance (Clcr), weight, height, body surface area, or gender. However, age exhibited a direct linear relationship with trough concentrations (Y in microgram/ml), Y = 0.020.age--0.541 (p < 0.003). We conclude that for patients with Clcr 30 ml/minute or above, age is a more important predictor of ciprofloxacin trough concentration than renal function. Dosage adjustment should not be arbitrary but should be guided by minimum inhibitory concentration, clinical response, and side effects.

Absorption↗