Biomedical subjects

Ruben D Restrepo

Publications and source records attributed to Ruben D Restrepo.

5 recordsLinked to original sources

PubMed2006

An investigation of nebulized bronchodilator delivery using a pediatric lung model of spontaneous breathing.

BACKGROUND: The literature lacks comparative data on nebulizer aerosol delivered via mask versus T-piece, to spontaneously breathing pediatric subjects. PURPOSE: To compare total inhaled drug mass delivered via standard pediatric aerosol mask versus via T-piece, with increasing distance. METHODS: We used a sample of 5 nebulizers, operated under manufacturers' conditions, with a standard pediatric aerosol mask and with a T-piece capped at one end, at 0 cm, 1 cm, and 2 cm from an inhalation filter placed at the inlet of a pediatric test lung. Inhaled drug mass was analyzed with spectrophotometry. Aerosol particle size was measured separately from the breathing simulations, using a laser particle sizer to determine fine-particle mass (particles < 4.7 mum) and fine-particle fraction as percent of total mass. The fine-particle fraction was used to estimate the fine-particle mass. RESULTS: The mean + SD values for inhaled drug mass as a percentage of nominal dose, at 0 cm, 1 cm, and 2 cm, with the mask were 2.88 + 0.79%, 1.61 + 0.65%, and 1.3 + 0.42%, respectively, and with the T-piece were 4.14 + 1.37%, 3.77 + 1.04%, and 3.47 + 0.64%, respectively. There was a statistically greater inhaled drug mass with T-piece than with mask, overall (p < 0.01), and a significant decrease with mask or T-piece as distance increased (p < 0.01). The difference between mask and T-piece for inhaled drug mass at 2 cm was statistically significant (p < 0.018). The mean + SD values for fine-particle mass estimated as a percentage of total drug mass at 0, 1, and 2 cm, with the mask were 1.39 + 0.36%, 0.78 + 0.29%, and 0.64 + 0.20%, respectively, and with the T-piece were 2.1 + 0.63%, 1.84 + 0.45%, and 1.71 + 0.27%, respectively. CONCLUSION: Inhaled drug mass was greater with T-piece than with a standard pediatric aerosol mask under the conditions studied.

Aerosols↗

PubMed2005

Halothane, an effective infrequently used drug, in the treatment of pediatric status asthmaticus: a case report.

Asthma is the most common chronic disease of childhood. Despite a better understanding of the disease process and its management, status asthmaticus continues to be a life-threatening event. The use of volatile inhaled anesthetics is infrequently reported as adjunctive therapy to conventional treatment of this condition. We report the use of halothane in a mechanically ventilated pediatric patient with life-threatening status asthmaticus who was admitted to the pediatric intensive care unit (PICU) after failing to respond to standard medical therapy and noninvasive positive pressure ventilation. A 12-year-old African American male was seen in the emergency department and treated with intravenous corticosteroids, beta-agonist therapy. He deteriorated rapidly and required endotracheal intubation and mechanical ventilation. Two hours later, the patient developed an acute, severe respiratory acidosis (pH=6.97, PaCO2=171, PaO2=162, BE=1.7). Halothane was started at 2% by using the Siemens Servo 900C anesthesia ventilator. Improvement in both arterial blood gases and exhaled tidal volume were noted 30 minutes after initiation of the anesthetic gas. The patient remained on halothane for a total of 36 hours. No adverse effects associated with the use of halothane were noted. The patient was extubated to BiPAP 16/6, FiO2=0.30 at 68 hours and was discharged home 5 days later.

Acidosis, Respiratory↗

PubMed2004

Performance comparison of nebulizer designs: constant-output, breath-enhanced, and dosimetric.

INTRODUCTION: Design differences among pneumatically powered, small-volume nebulizers affect drug disposition (percentage of the dose delivered to the patient, lost to deposition in the equipment, and lost via exhalation to ambient air) and thus affect drug availability and efficacy. OBJECTIVE: Evaluate in vitro the dose disposition with 5 nebulizer models, of 3 types (constant-output, breath-enhanced, and dosimetric), using simulated normal, adult breathing. METHODS: We compared 5 nebulizer models: 2 constant-output (Misty-Neb and SideStream), 1 breath-enhanced (Pari LCD), and 2 dosimetric (Circulaire and AeroEclipse). Each nebulizer was filled with a 3-mL unit-dose of albuterol sulfate and powered by oxygen at 8 L/min. The nebulizers were connected to an induction throat, connected to a breathing simulator. We measured (1) inhaled drug (subdivided into mass deposited in the induction throat and mass deposited in the filter at the distal end of the induction throat), (2) exhaled drug (lost to the ambient air), (3) drug lost to deposition in the apparatus, and (4) drug left in the unit-dose bottle. The duration of nebulization (until sputter) was measured with a stopwatch. All drug amounts were analyzed via spectrophotometry and expressed as a percentage of the total dose. RESULTS: The mean +/- SD inhaled drug percentages were: Misty-Neb 17.2 +/- 0.4%, SideStream 15.8 +/- 2.8%, Pari LCD 15.2 +/- 4.2%, Circulaire 8.7 +/- 1.0%, and AeroEclipse 38.7 +/- 1.3%. The mean +/- SD percentages of drug lost to the ambient air were: Misty-Neb 26.8 +/- 0.7%, SideStream 17.3 +/- 0.4%, Pari LCD 18.3 +/- 0.8%, Circulaire 12.3 +/- 0.8%, and AeroEclipse 6.6 +/- 3.3%. The mean +/- SD percentages of drug lost to deposition in the apparatus were: Misty-Neb 52.3 +/- 0.6%, SideStream 63.4 +/- 3.0%, Pari LCD 62.5 +/- 4.0%, Circulaire 75.8 +/- 0.5%, and AeroEclipse 51.0 +/- 2.1%. Duration of nebulization was shortest with the Circulaire and longest with the AeroEclipse (p < 0.05 via 1-way analysis of variance). CONCLUSIONS: The nebulizers we tested differ significantly in overall drug disposition. The dosimetric AeroEclipse provided the largest inhaled drug mass and the lowest loss to ambient air, with the test conditions we used. method.

Administration, Inhalation↗

PubMed2003

Nebulized bronchodilator formulations: unit-dose or multi-dose?

BACKGROUND: Nosocomial infections linked to the use of multi-dose bronchodilator nebulizer formulations have been reported in the literature. OBJECTIVE: Survey American hospital respiratory therapy services to determine practice patterns, opinions, and awareness regarding unit-dose and multi-dose bronchodilator formulations. METHODS: A quota sample targeted 4 hospital size categories (0-100 beds, 101-200 beds, 201-400 beds, and > 400 beds) using a listing of general medical/surgical hospitals from the American Hospital Association. Hospitals were contacted via telephone to identify the director of respiratory therapy services, who was invited to complete a 29-item Web-based survey of their hospital practices and their opinions about and knowledge of issues with multi-dose and unit-dose bronchodilator formulations. RESULTS: One thousand forty-seven hospitals were recruited and 409 valid surveys were completed (completion rate 39%). The reported mean +/- SD percentage of unit-dose nebulizer treatments was 80.2 +/- 26.2%. Seventy-two percent (296) of respondents indicated having a policy and procedure manual that deals specifically with nebulized bronchodilator solutions, but only 107 reported having internal monitoring guidelines for compliance with those policies and procedures. Multi-dose bottles of bronchodilator concentrate were used with multiple patients in 77% of cases, and on average 9.7 +/- 8.5 patients were treated with the same multi-dose bottle. Eighty-one percent of respondents reported that treatments from multi-dose bottles are prepared at the bedside. The length of time a multi-dose bottle was kept (after being opened) ranged from 24 hours (8%) to 1 month (11%), and only 3% of respondents reported following manufacturers' recommendations. In the respondents' opinion the chief advantage of multi-dose was cost per dose (84%), and the chief advantage of unit-dose was less risk of contamination (92%). With other factors (therapist time, cost of saline diluent for multi-dose concentrate, dose-error, and contamination) considered, 73% thought that unit-dose vials were more cost-effective. Three hundred thirty-six respondents (82%) thought that a sterile, low-volume (0.5 mL) unit-dose vial of bronchodilator concentrate would be useful, and 249 (74%) of those 336 respondents indicated that such a formulation would replace multi-dose bottles. Only 56% of respondents knew about the evidence regarding the risk of contamination with multi-dose bottles. CONCLUSIONS: Multi-dose bottles of bronchodilator solution are used in approximately 20% of nebulizer treatments, and without strict adherence to infection control procedures they are a potential source of nosocomial infection. A sterile, low-volume unit-dose vial of bronchodilator concentrate would be a useful alternative to multi-dose concentrate for modifying doses or mixing drugs in nebulizer therapy.

Attitude of Health Personnel↗

PubMedDate not supplied

Protocol-driven ventilator management in children: comparison to nonprotocol care.

The purpose of this study was to compare ventilator weaning time, time to spontaneous breathing, and overall ventilator hours duration with use of a ventilator management protocol (VMP) versus standard nonprotocol-based care in a pediatric intensive care unit. A multidisciplinary task force developed a comprehensive protocol for ventilator management with four specific phases: initial ventilator set up and adjustment, weaning, minimal settings, and spontaneous mode prior to extubation. Medical records of ventilated patients both before and after protocol implementation were reviewed. A total of 187 patients were studied (89 nonprotocol and 98 VMP patients). No differences were seen between groups in PRISM scores, Murray scores, or oxygenation indices, but VMP patients were significantly younger (P =.03). Ventilator weaning times (P =.005) and time to spontaneous breathing modes (P =.006) were significantly decreased in VMP patients compared to nonprotocol patients, but overall ventilator duration was not significantly different. No significant differences were seen in extubation failure, use of corticosteroids, or use of racemic epinephrine between groups. Use of an institution-specific VMP developed by a multidisciplinary team was associated with significantly reduced ventilator weaning time and time to spontaneous breathing. Further studies are needed.

Adolescent↗