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Results for “randomized crossover trial”

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PubMed1995

Increasing organ blood flow during cardiopulmonary bypass in pigs: comparison of dopamine and perfusion pressure.

OBJECTIVE: To determine whether low-dose dopamine infusion (5 micrograms/kg/min) during cardiopulmonary bypass selectively increases perfusion to the kidney, splanchnic organs, and brain at low (45 mm Hg) as well as high (90 mm Hg) perfusion pressures. DESIGN: Randomized crossover trial. SETTING: Animal research laboratory in a university medical center. SUBJECTS: Ten female Yorkshire pigs (weight 29.9 +/- 1.2 kg). INTERVENTION: Anesthetized pigs were placed on normothermic cardiopulmonary bypass at a 100-mL/kg/min flow rate. After baseline measurements, the animal was subjected, in random sequence, to 15-min periods of low perfusion pressure (45 mm Hg), low perfusion pressure with dopamine (5 micrograms/kg/min), high perfusion pressure (90 mm Hg), and high perfusion pressure with dopamine. Regional perfusion (radioactive microspheres) was measured in tissue samples (2 to 10 g) from the renal cortex (outer two-third and inner one-third segments), stomach, duodenum, jejunum, ileum, colon, pancreas, and cerebral hemispheres. MEASUREMENTS AND MAIN RESULTS: Systemic perfusion pressure was altered by adjusting pump flow rate (r2 = .61; p < .05). In the kidney, cortical perfusion pressure increased from 178 +/- 16 mL/min/100 g at the low perfusion pressure to 399 +/- 23 mL/min/100 g at the high perfusion pressure (p < .05). Perfusion pressure augmentation increased the ratio of outer/inner renal cortical blood flow from 0.9 +/- 0.1 to 1.2 +/- 0.1 (p < .05). At each perfusion pressure, low-dose dopamine had no beneficial effect on renal perfusion or flow distribution. Similar results were found in the splanchnic organs, where regional perfusion was altered by perfusion pressure but not by dopamine. In contrast, neither changing perfusion pressure nor adding low-dose dopamine altered blood flow to the cerebral cortex. CONCLUSIONS: These data indicate that the lower autoregulatory limits of perfusion to the kidneys and splanchnic organs differ from those limits to the brain during normothermic bypass. Selective vasodilation from low-dose dopamine was not found in renal, splanchnic, or cerebral vascular beds. Increasing the perfusion pressure by pump flow, rather than by the addition of low-dose dopamine, enhanced renal and splanchnic but not cerebral blood flows during cardiopulmonary bypass.

Animals↗

PubMed1980

Comparison of rifampin and ampicillin in day care center contacts of Haemophilus influenzae type b disease.

A prospective, randomized, crossover trial was conducted comparing therapy with rifampin to therapy with ampicillin in eradicating Haemophilus influenzae type b carriage. Twenty-eight carriers were identified in a day care center following exposure to a patient with H influenzae type b meningitis; 26 children were randomly assigned to treatment with either ampicillin (100 mg/kg for five days) or rifampin (20 mg/kg for four days). Cultures were repeated two and four days after discontinuing therapy. In the initial trial, 6/17 children (35%) remained culture positive after treatment with ampicillin compared to 0/9 children treated with rifampin (P = .106). The six children who were ampicillin treatment failures had H influenzae type b isolates sensitive to that drug. These children were subsequently treated with rifampin and their cultures became negative. (For both trials, P = .027). Repeat cultures 30 days after therapy in 20 treated children revealed one culture positive for H influenzae type b. No further cases developed in the day care center (four months of follow-up). These data suggest that rifampin may be more effective than ampicillin in chemoprophylaxis of contacts of H influenzae type b disease.

Ampicillin↗

PubMedDate not supplied

Impact of ginkgo biloba on the pharmacokinetics of digoxin.

Many medications are known to alter digoxin pharmacokinetics, including the herbal medication St. John's wort. An open-labeled, randomized, crossover trial was conducted in eight healthy human volunteers to determine if ginkgo biloba (GB) also alters the pharmacokinetics of digoxin. On two occasions separated by 2 weeks, subjects ingested digoxin, 0.5 mg. One week prior to each study phase, half of the volunteers were randomly initiated on GB therapy, 80 mg three times daily, that continued until the end of the study phase. Immediately prior to and for 36 hours following digoxin ingestion, multiple blood samples were collected for digoxin plasma concentration determination. No significant difference between treatments was observed with respect to AUC(0- infinity ) (digoxin alone: 21.0 +/- 8.6 [ng/mL] x h; digoxin + GB: 25.6 +/- 13.2 [ng/mL] x h). Additionally, no significant difference between therapies was observed with respect to C(max), T(max), or Cl(o). In six subjects, k(e) and t(1/2) were able to be determined. These parameters also did not differ significantly between treatments. In conclusion, within the context of the specific GB product used during this investigation, the concomitant use of GB and digoxin did not appear to have any significant effect on the pharmacokinetics of orally administered digoxin in healthy volunteers.

Adult↗

PubMed2005

Enhanced renoprotective effects of ultrahigh doses of irbesartan in patients with type 2 diabetes and microalbuminuria.

BACKGROUND: The purpose of this study was to evaluate the renoprotective effect as reflected by short-term changes in albuminuria of ultrahigh doses of irbesartan in type 2 diabetic patients with microalbuminuria. METHODS: This double-masked randomized crossover trial included 52 (41 males) hypertensive type 2 diabetic patients with microalbuminuria on ongoing antihypertensive medication. At inclusion, previous antihypertensive treatment was discontinued and replaced with bendroflumethiazide, 5 mg once daily, for the entire study. Following 2 months wash-out (baseline), patients were treated randomly with irbesartan 300, 600, and 900 mg once daily, each dose for 2 months. End points evaluated at the end of each study period included urinary albumin excretion rate (UAE) (mean of three 24-hour collections), 24-hour ambulatory blood pressure, and glomerular filtration rate (GFR) [chromium 51 ethylenediaminetetraacetic acid (51Cr-EDTA)]. RESULTS: Baseline values were: 24-hour UAE [geometric mean (95% CI)] 134 (103 to 170) mg/24 hours, ambulatory blood pressure [mean (SD)] 140 (10)/77 (7) mm Hg, and GFR 103 (19) mL/min/1.73 m2. All doses of irbesartan significantly reduced UAE, ambulatory blood pressure, and GFR from baseline. Reductions in UAE from baseline were 52% (46% to 57%), 49% (43% to 54%), and 59% (54% to 63%) with increasing doses of irbesartan (P < 0.01). UAE was reduced significantly more by irbesartan 900 mg compared with lower doses with an additional reduction in UAE of 15% (2% to 26%) by irbesartan 900 mg compared with 300 mg (P = 0.02). The greater reduction in albuminuria by irbesartan 900 vs. 300 mg was more pronounced in patients with UAE during irbesartan 300 mg above vs. below the median [31% (18% to 42%) vs. -9% (-25% to 6%), respectively (P < 0.05)]. With increasing doses systolic ambulatory blood pressure was reduced from baseline by 8 (4 to 12), 9 (5 to 13), and 9 (5 to13) mm Hg, and diastolic ambulatory blood pressure by 6 (4 to 7), 7 (6 to 9), and 7 (6 to 9) mm Hg (NS between doses). CONCLUSION: Ultrahigh dosing of irbesartan (900 mg once daily) is generally safe and offers additional renoprotection independent of changes in systemic blood pressure and GFR in comparison to the currently recommended dose of 300 mg.

Aged↗

PubMed1998

The effects of relative timing of sirolimus and cyclosporine microemulsion formulation coadministration on the pharmacokinetics of each agent.

INTRODUCTION: Sirolimus and cyclosporine (INN, ciclosporin) share the same cytochrome P4503A metabolic pathways, and both drugs are substrates for p-glycoprotein countertransport. These factors most likely affect the bioavailability of both drugs. This study served to examine whether the timing of the administration of cyclosporine and sirolimus might significantly affect the relative bioavailability of one or both of these drugs. METHODS: In this randomized crossover trial, 24 stable kidney transplant recipients who were treated after transplant with a combination of sirolimus, cyclosporine, and prednisone for at least 3 months before study initiation, received individualized doses of sirolimus once daily and cyclosporine in the microemulsion formulation twice a day. A total of 20 patients completed the full crossover design. Patients were randomized to one of two dosing schedules: 10 of the patients who completed the study received the morning doses of sirolimus and cyclosporine concomitantly for the first 7 days (schedule I), and from days 8 to 14 the sirolimus dose was administered 4 hours after the morning cyclosporine dose. Ten of the patients received the sirolimus dose 4 hours after the morning cyclosporine dose for the first 7 days (schedule II), and from days 8 to 14 they received concomitant morning doses of cyclosporine and sirolimus. Pharmacokinetic profiles of sirolimus and cyclosporine performed on all patients on days 7, 14, and 15 yielded the area under the concentration-time curve (AUC), peak concentration (Cmax), time to Cmax (tmax), trough cyclosporine concentration (Co), and trough sirolimus concentration (Co) values. RESULTS: Sirolimus AUC and sirolimus trough levels were consistently and significantly higher when both cyclosporine and sirolimus were administered concomitantly than when they were administered 4 hours apart. No effect attributable to timing of drug administration could be found on cyclosporine pharmacokinetic parameters. CONCLUSION: This study shows that the relative timing of administration of cyclosporine and sirolimus significantly affects the blood concentrations of sirolimus.

Adult↗

PubMed2002

Midodrine in neurally mediated syncope: a double-blind, randomized, crossover study.

Neurally mediated syncope is the most frequent cause of syncope in patients without structural heart disease. Its most common trigger is a reduction in venous return to the heart due to excessive venous pooling in the legs. We conducted a double-blind, randomized, crossover trial to investigate the efficacy of midodrine, a selective alpha-1 adrenergic agonist that decreases venous capacitance, in preventing neurally mediated syncope triggered by passive head-up tilt. Twelve patients with history of recurrent neurally mediated syncope, which was reproduced during head-up tilt, were randomized to receive a nonpressor dose of midodrine (5mg) or placebo on day 1 and the opposite on day 3. One hour after drug or placebo administration, patients underwent 60-degree head-up tilt lasting 40 minutes (unless hypotension or bradycardia developed first). In the supine position, midodrine produced no significant change in blood pressure or heart rate. The responses to head-up tilt were significantly different on the midodrine and the placebo day: on the placebo day, 67% (8/12) of the subjects suffered neurally mediated syncope, whereas only 17% (2/12) of the subjects developed neurally mediated syncope on the midodrine day (p < 0.02). These results indicate that midodrine significantly improves orthostatic tolerance during head-up tilt in patients with recurrent neurally mediated syncope.

Adult↗

PubMed2002

Health-related quality-of-life assessments and patient-physician communication: a randomized controlled trial.

CONTEXT: There has been increasing interest in the use of health-related quality-of-life (HRQL) assessments in daily clinical practice, yet few empirical studies have been conducted to evaluate the usefulness of such assessments. OBJECTIVE: To evaluate the efficacy of standardized HRQL assessments in facilitating patient-physician communication and increasing physicians' awareness of their patients' HRQL-related problems. DESIGN: Prospective, randomized crossover trial. SETTING: Outpatient clinic of a cancer hospital in the Netherlands. PARTICIPANTS: Ten physicians and 214 patients (76% women; mean age, 57 years) undergoing palliative chemotherapy who were invited to participate between June 1996 and June 1998. INTERVENTION: At 3 successive outpatient visits, patients completed an HRQL questionnaire (European Organization for Research and Treatment of Cancer Quality of Life Questionnaire-Core 30). The responses were computer scored and transformed into a graphic summary. Physicians and patients received a copy of the summary before the consultation. MAIN OUTCOME MEASURES: Audiotapes of the consultations were content analyzed to evaluate patient-physician communication. Physicians' awareness of their patients' health problems was assessed by comparing physicians' and patients' ratings on the Dartmouth Primary Care Cooperative Information Functional Health Assessment (COOP) and the World Organisation Project of National Colleges and Academics (WONCA) charts. RESULTS: The HRQL-related issues were discussed significantly more frequently in the intervention than in the control group (mean [SD] communication composite scores: 4.5 [2.3] vs 3.7 [1.9], respectively (P =.01). Physicians in the intervention group identified a greater percentage of patients with moderate-to-severe health problems in several HRQL domains than did those in the control group. All physicians and 87% of the patients believed that the intervention facilitated communication and expressed interest in its continued use. CONCLUSION: Incorporating standardized HRQL assessments in daily clinical oncology practice facilitates the discussion of HRQL issues and can heighten physicians' awareness of their patients' HRQL.

Communication↗

PubMedDate not supplied

Gait efficiency using the C-Leg.

Microprocessor-controlled prosthetic knees are claimed to improve gait efficiency in transfemoral (TF) amputees. This hypothesis was tested in a prospective randomized crossover trial that compared the Mauch SNS knee and the C-Leg microprocessor-controlled knee in eight TF amputees. The subjects were given a 3-month acclimation period in each knee. Then, their net oxygen cost (mL/kg/m) was measured while they walked overground at four speeds in random order: 0.8 m/s, 1.0 m/s, 1.3 m/s, and self-selected walking speed (SSWS). The C-Leg caused small reductions in net oxygen cost that were not statistically significant compared with the Mauch SNS at any of the walking speeds (p > 0.190). Subjects chose higher SSWSs with the C-Leg compared with the Mauch SNS (mean +/- standard deviation = 1.31 +/- 0.12 m/s vs 1.21 +/- 0.10 m/s, respectively, p = 0.046) but did not incur higher oxygen costs (p = 0.270), which suggests greater efficiency only at their SSWS.

Adult↗

PubMed2006

Role of nonbronchoscopic lavage for investigating alveolar inflammation and permeability in acute respiratory distress syndrome.

OBJECTIVE: Nonbronchoscopic bronchoalveolar lavage is often used as an alternative to bronchoscopic bronchoalveolar lavage in the diagnosis of ventilator-associated pneumonia. We have previously reported an improved safety profile for nonbronchoscopic lavage in patients with lung injury, suggesting that this may be a better technique in this patient group. The objective of this study was to determine whether nonbronchoscopic lavage could be used as an alternative to bronchoscopic lavage for the assessment of alveolar permeability and inflammation in patients at risk for acute respiratory distress syndrome (ARDS) or with ARDS. DESIGN: Prospective randomized crossover trial. PATIENTS: Intubated patients with ARDS or at risk of ARDS. INTERVENTIONS: Bronchoscopic and nonbronchoscopic lavage in the same patient, 15 mins apart. MEASUREMENTS AND MAIN RESULTS: Twenty-one patients with ARDS and 20 patients at risk of ARDS were recruited and underwent nonbronchoscopic and bronchoscopic lavage in randomized order. Despite similar volumes of lavage fluid, nonbronchoscopic lavage had fewer cells and an increased ratio of bronchial epithelial cells to macrophages. Although average concentrations of myeloperoxidase and total protein, the protein permeability index, and the epithelial-lining fluid volume were similar with the two techniques and demonstrated moderate linear associations, Bland and Altman analysis revealed poor comparability, with substantial side-to-side variability and wide 95% limits of agreement. Furthermore, unlike bronchoscopic lavage, nonbronchoscopic lavage was unable to differentiate between patients with ARDS and those at risk of ARDS. CONCLUSIONS: Nonbronchoscopic lavage is not comparable to bronchoscopic lavage and as such cannot be used as an alternative to bronchoscopic lavage for assessing alveolar inflammation in patients with ARDS.

Adult↗

PubMedDate not supplied

Pharmacokinetic evaluation of a new oral cyclosporine formulation.

STUDY OBJECTIVE: To compare the pharmacokinetics of a new oral cyclosporine preparation with those of cyclosporine solution diluted in Isocal and the intravenous formulation. DESIGN: Randomized, crossover trial. SETTING: Tertiary care referral center. PATIENTS: Seven pediatric liver transplant recipients who were receiving oral cyclosporine as part of their immunosuppressive regimen. All patients completed the study. INTERVENTIONS: Pharmacokinetic studies were performed with the intravenous and oral dosage forms. Patients received one dose of intravenous cyclosporine, and then were randomized to receive their usual oral cyclosporine dose incorporated into a chocolate wafer or mixed with Isocal. After a minimum of 3 days, the alternative preparation was administered. Serial cyclosporine blood samples were collected at predetermined intervals for 12 hours after the third dose for each regimen. Concentrations were determined by high-performance liquid chromatography. The data for the three dosage forms were fit simultaneously with a two-compartment model. MEASUREMENTS AND MAIN RESULTS: No difference was seen in F, ka, Cmax, and tmax between the two oral cyclosporine preparations (p > 0.05). No new rejection episodes occurred during the study period. CONCLUSIONS: We conclude there is no difference in the bioavailability of the oral solution and the chocolate formulation. We believe the new preparation may increase patient compliance and ensure administration of a complete dose compared with the currently marketed solution.

Administration, Oral↗

PubMed1999

Acute treatment of migraine attacks: efficacy and safety of a nonsteroidal anti-inflammatory drug, diclofenac-potassium, in comparison to oral sumatriptan and placebo. The Diclofenac-K/Sumatriptan Migraine Study Group.

BACKGROUND: Migraine attacks are often treated with simple analgesics or with ergotamine-containing preparations alone or in combination with anti-emetics. Although also sometimes used to treat migraine, nonsteroidal anti-inflammatory drugs (NSAIDs) have not been systematically evaluated in controlled clinical trials, particularly in comparison with the newer drug sumatriptan. Sumatriptan is a specific migraine treatment which has recently become among the most widely prescribed acute migraine therapies. However, while effective, it has low oral bioavailability and some problematic adverse effects. Diclofenac-potassium is a potent NSAID available as a fast-acting oral tablet, which has been shown to be safe and effective in several other acute pain indications. In the clinical trial reported here, the efficacy and safety of diclofenac-potassium in the acute treatment of migraine attacks has been tested in comparison with oral sumatriptan and placebo. METHODS: Single oral doses of 50 mg and 100 mg diclofenac-potassium were compared to a single oral dose of 100 mg sumatriptan and placebo in a double-blind randomized crossover trial in 156 adult patients suffering from migraine attacks, with or without aura, selected according to the International Headache Society diagnostic criteria. The primary efficacy criterion was migraine headache pain recorded on a visual analog scale at 2 h after dosing. Secondary endpoints included pain at other time points up to 8 h and the presence of accompanying symptoms (nausea, vomiting, photophobia, phonophobia). FINDINGS: Diclofenac-potassium was more effective than placebo in reducing migraine headache pain at 2 h after dosing, which was the primary endpoint. Secondary analyses showed that diclofenac-potassium provided significant pain relief from 60 min after dosing and for all remaining endpoints in the 8-h observation period. Both 50 and 100 mg doses of diclofenac-potassium were similarly effective. A similar effect was shown with sumatriptan; however, significant superiority to placebo was seen only from the 90-min time point. Diclofenac-potassium was generally superior to placebo or sumatriptan in reducing accompanying symptoms, particularly nausea. Diclofenac-potassium seemed to be as well tolerated as placebo, with fewer adverse events reported than after sumatriptan treatment and with more patients assessing the overall tolerability of diclofenac-potassium better than that of sumatriptan. INTERPRETATION: Compared with placebo and the reference therapy sumatriptan, diclofenac-potassium is an effective, fast-acting, and well-tolerated acute oral therapy for migraine attacks, with advantages over oral sumatriptan in terms of onset of analgesic effect, reduction of accompanying symptoms, and tolerability profile. It may therefore be useful as an alternative oral therapy for migraine attacks.

Administration, Oral↗

PubMed2002

Acitretin for chemoprevention of non-melanoma skin cancers in renal transplant recipients.

A prospective, open randomized crossover trial was conducted to evaluate the efficacy of acitretin for chemoprevention of squamous cell carcinomas and basal cell carcinomas in renal allograft recipients. Analysis was performed according to the intention-to treat principle. Twenty-three patients with previous history of non-melanoma skin cancer enrolled into the study and were randomly allocated into two groups. They crossed over at the end of 1 year. Eleven (47.8%) patients completed the 2-year trial. Twelve (52.2%) patients withdrew from the trial. Nine of these withdrew because of side-effects of acitretin. The majority of the patients who continued with the acitretin could tolerate 25 mg of acitretin daily or on alternate days. The number of squamous cell carcinomas (SCC) observed in patients while on acitretin was significantly lower than that in the drug-free period (P = 0.002). A similar trend was observed in patients with basal cell carcinomas, but this was not significant and the numbers were small. Side-effects were a major limiting factor. A severe rebound increase in SCC occurred in one patient after the acitretin was ceased.

Acitretin↗

PubMed2003

Insulin detemir is characterized by a consistent pharmacokinetic profile across age-groups in children, adolescents, and adults with type 1 diabetes.

OBJECTIVE: This trial aimed to characterize for the first time the pharmacokinetic profile of insulin detemir, the novel soluble basal insulin analog, in children and adolescents compared with adults. Comparisons were also made with NPH insulin to determine any between-treatment difference in the effect of age on pharmacokinetic profile. RESEARCH DESIGN AND METHODS: This single-center, open-label, randomized, crossover trial included children (aged 6-12 years, n = 13), adolescents (aged 13-17 years, n = 10), and adults (aged 18-65 years, n = 11) of both sexes. Subjects were given single doses of 0.5 units/kg s.c. insulin detemir or 0.5 IU/kg NPH insulin on 2 separate days. Serial blood sampling was performed for 24 h for analysis of serum insulin detemir, human insulin, and glucose concentrations. RESULTS: The mean pharmacokinetic profile of insulin detemir was similar across all three age-groups. This was determined by statistical analyses of the data, which showed no overall age effect or between-group differences when pairwise comparisons were made between children (or adolescents) and adults on the parameters of the area under the curve (AUC), AUC from zero to infinity, AUC from 0 to 24 h [AUC((0-24 h))], and the maximum concentration measured during the 24 h after closing. No overall age effect for AUC((0-24 h)) and C(max) was detected for NPH insulin, but data were only analyzable from seven adults and pairwise comparisons did indicate that children and adults had different pharmacokinetic profiles. Less total variability in the pharmacokinetics of insulin detemir than NPH insulin was indicated by lower coefficients of variation in AUC, C(max), and time to maximum concentration in all three age-groups. CONCLUSIONS: The data suggest that insulin detemir can be used in children and adolescents with type 1 diabetes using titration guidelines similar to those used in adults. Moreover, insulin detemir may offer the advantage of greater predictability of response in comparison to NPH insulin due to lower total variability and a lesser degree of kinetic disparity across age-groups.

Adolescent↗

PubMed2001

Efficacy of a high-carbohydrate diet in catabolic illness.

OBJECTIVE: To determine within the setting of isocaloric, isonitrogenous enteral diets whether a diet that supplies most of its calories from fat or carbohydrate would be most beneficial at limiting muscle protein wasting in catabolic illness. DESIGN: Prospective, randomized, crossover trial. SETTING: Academic pediatric burn unit in tertiary medical center. PATIENTS: Fourteen severely burned (>40% total body surface area) children underwent systemic metabolic and cross-leg muscle protein kinetic studies. INTERVENTIONS: All were treated clinically in a similar manner, including early excision and grafting, antimicrobial therapy, and isocaloric, isonitrogenous enteral nutritional support. Subjects randomly received either a high-carbohydrate enteral diet (3% fat, 82% carbohydrate, 15% protein), or a high-fat enteral diet (44% fat, 42% carbohydrates, 14% protein) for 1 week and then crossed over to the other diet for a second week. MEASUREMENTS AND MAIN RESULTS: On day 5 of each diet, muscle protein kinetics were determined from femoral arterial and venous blood samples during a primed-constant d5-phenylalanine infusion. Indirect calorimetry was used to determine systemic resting energy expenditure and respiratory quotient. The seven boys and seven girls were 7.1 +/- 1.1 (mean +/- sem) years old and suffered burns over 65 +/- 4% of their bodies, with 52 +/- 6% being third-degree burns. Muscle protein degradation markedly decreased (p <.01) with administration of the high-carbohydrate diet. Protein synthesis was unaltered. Endogenous insulin concentrations increased during the high-carbohydrate feeding period. No differences in energy expenditure were seen between study diets. CONCLUSIONS: In severely burned pediatric patients, enteral nutrition supplied predominantly as carbohydrate rather than fat improves the net balance of skeletal muscle protein across the leg. This is attributable to decreased protein breakdown, suggesting a protein-sparing effect of high-carbohydrate feedings.

Amino Acids↗

PubMed2005

Kinetic therapy improves oxygenation in critically ill pediatric patients.

OBJECTIVE: To compare changes in oxygenation after manual turning and percussion (standard therapy) and after automated rotation and percussion (kinetic therapy). DESIGN: Randomized crossover trial. SETTING: General and cardiac pediatric intensive care units. PATIENTS: Intubated and mechanically ventilated pediatric patients who had an arterial catheter and no contraindications to using a PediDyne bed. INTERVENTIONS: Patients were placed on a PediDyne bed (Kinetic Concepts) and received 18 hrs blocks of standard and kinetic therapy in an order determined by randomization. MEASUREMENTS AND MAIN RESULTS: Arterial blood gases were measured every 2 hrs during each phase of therapy. Oxygenation index and arterial-alveolar oxygen tension difference [P(A-a)O(2)] were calculated. Indexes calculated at baseline and after each 18-hr phase of therapy were analyzed. Fifty patients were enrolled. Data from 15 patients were either not collected or not used due to reasons that included violation of protocol and inability to tolerate the therapies in the study. Indexes of oxygenation were not normally distributed and were compared using Wilcoxon signed rank testing. Both therapies led to improvements in oxygenation, but only those from kinetic therapy achieved statistical significance. In patients receiving kinetic therapy first, median oxygenation index decreased from 7.4 to 6.19 (p = .015). The median P(A-a)O(2) decreased from 165.2 to 126.4 (p = .023). There were continued improvements in oxygenation after the subsequent period of standard therapy, with the median oxygenation index decreasing to 5.52 and median P(A-a)O(2) decreasing to 116.0, but these changes were not significant (p = .365 and .121, respectively). When standard therapy was first, the median oxygenation index decreased from 8.83 to 8.71 and the median P(a-a)o(2) decreased from 195.4 to 186.6. Neither change was significant. Median oxygenation index after the subsequent period of kinetic therapy was significantly lower (7.91, p = .044) and median P(A-a)O(2) trended lower (143.4, p = .077). CONCLUSIONS: Kinetic therapy is more efficient than standard therapy at improving oxygenation and produces improvements in oxygenation that are more persistent.

Analysis of Variance↗

PubMed2001

Effects of preemptive atropine administration on incidence of medetomidine-induced bradycardia in dogs.

OBJECTIVE: To determine the cardiorespiratory effects of preemptive atropine administration in dogs sedated with medetomidine. DESIGN: Randomized crossover trial. ANIMALS: 12 healthy adult dogs. PROCEDURES: Dogs underwent 6 treatments. Each treatment consisted of administration of atropine (0.04 mg/kg [0.018 mg/lb] of body weight, IM) or saline solution (0.9% NaCl, 1 ml, IM) and administration of medetomidine (10, 20, or 40 microg/kg [4.5, 9.1, or 18.2 microg/lb], IM) 10 minutes later. Treatments were administered in random order, with a minimum of 1 week between treatments. Cardiorespiratory effects before and after atropine and medetomidine administration were assessed. Duration of lateral recumbency and quality of sedation and recovery were assessed. RESULTS: Bradycardia (heart rate < 60 beats/min) was seen in all dogs when saline solution was administered followed by medetomidine, and the dose of medetomidine was not associated with severity or frequency of bradycardia or second-degree heart block. However, a medetomidine dose-dependent increase in mean and diastolic blood pressures was observed, regardless of whether dogs received saline solution or atropine. Preemptive atropine administration effectively prevented bradycardia and second-degree heart block but induced pulsus alternans and hypertension. The protective effects of atropine against bradycardia lasted 50 minutes. Blood gas values were within reference limits during all treatments and were not significantly different from baseline values. Higher doses of medetomidine resulted in a longer duration of lateral recumbency. CONCLUSIONS AND CLINICAL RELEVANCE: Preemptive administration of atropine in dogs sedated with medetomidine effectively prevents bradycardia for 50 minutes but induces hypertension and pulsus alternans.

Adrenergic alpha-Agonists↗

PubMed1987

Nabilone versus prochlorperazine for control of cancer chemotherapy-induced emesis in children: a double-blind, crossover trial.

In a randomized, double-blind, crossover trial, nabilone was compared to prochlorperazine for control of cancer chemotherapy-induced emesis in 30 children 3.5 to 17.8 years of age. All subjects received two consecutive identical cycles of chemotherapy with the trial antiemetics given in accordance to a body weight-based dosage schedule beginning eight to 12 hours before treatment. The overall rate of improvement of retching and emesis was 70% during the nabilone and 30% during the prochlorperazine treatment cycles (P = .003, chi 2 test). On completion of the trial, 66% of the children stated that they preferred nabilone, 17% preferred prochlorperazine, and 17% had no preference (P = .015, chi 2 test). Major side effects (dizziness, drowsiness, and mood alteration) were more common (11% v 3%) during the nabilone treatment cycles. CNS side effects appeared to be dose related and were most likely to occur when the nabilone dosage exceeded 60 micrograms/kg/d, but individual tolerance to nabilone varied considerably. Lower dosages of nabilone were associated with equivalent efficacy and no major side effects. Nabilone appears to be a safe, effective, and well-tolerated antiemetic drug for children receiving cancer chemotherapy. Although major side effects may occur at higher dosages, nabilone is preferable to prochlorperazine because of improved efficacy.

Adolescent↗

PubMed2004

A randomized trial of furosemide vs hydrochlorothiazide in patients with chronic renal failure and hypertension.

BACKGROUND: Loop diuretics are the drugs of choice for the treatment of hypertension in chronic renal failure patients. However, the adaptive changes in the distal nephron and the short half-life of these drugs may decrease their long-term efficacy. Thiazides are not believed to be efficient in advanced renal failure, but this is debated. METHODS: We compared the efficacy of long-acting furosemide (60 mg/day) and hydrochlorothiazide (25 mg/day) in a double-blind, randomized crossover trial in seven patients with severe renal failure and hypertension (seven men, 54+/-10 years old). The primary end-points were sodium and chloride fractional excretions after 1 month of each diuretic and then after their combination. During the trial, other treatments and the diet were controlled. RESULTS: A trend towards an increase in the fractional excretion of sodium and of chloride was observed with furosemide, but the difference did not reach the level of statistical significance (P = NS). Hydrochlorothiazide significantly increased fractional excretion of sodium and chloride from 3.7+/-0.9 to 5.5+/-0.3 and from 3.9+/-0.19 to 6.5+/-0.3, respectively (P<0.05). The combination of the two diuretics had no additional effect on the increase in sodium and chloride fractional excretion. Furosemide, hydrochlorothiazide and the combination of the two diuretics decreased mean arterial blood pressure by the same extent from 112 to 97, 99 and 97 mmHg, respectively (P<0.05). CONCLUSIONS: Hydrochlorothiazide increased the fractional excretion of sodium and chloride more than furosemide did in hypertensive severe renal failure patients. Mean arterial blood pressure decreased by the same amount with both diuretics. Combining furosemide and hydrochlorothiazide did not increase the efficacy of hydrochlorothiazide.

Adult↗