Biomedical subjects

A G Bailey

Publications and source records attributed to A G Bailey.

16 recordsLinked to original sources

PubMed1999

Tracheal extubation of deeply anesthetized pediatric patients: a comparison of isoflurane and sevoflurane.

UNLABELLED: We studied the emergence characteristics of unpremedicated children tracheally extubated while deeply anesthetized ("deep extubation") with isoflurane or sevoflurane. Forty children were assigned to one of two groups, Group I or Group S. At the end of the operation, Group I patients were extubated while breathing 1.5 times the minimum alveolar anesthetic concentration (MAC) of isoflurane. Group S patients were tracheally extubated while breathing 1.5 times the MAC of sevoflurane. Recovery characteristics and complications were noted. Group S patients were arousable sooner than Group I patients (10.1 + 6.5 vs 16.3 + 9.9 min). Later arousal scores and times to discharge were the same. There were no serious complications in either group. Breath-holding was more common in Group I. We conclude that the overall incidence of airway problems and desaturation episodes was similar between groups. Emergency delirium was common in both groups (32% overall: 40% for Group I, 25% for Group S). IMPLICATIONS: Deep extubation of children can be safely performed with either isoflurane or sevoflurane. After deep tracheal extubation, airway problems occur but are easily managed. Return to an arousable state occurred more quickly with sevoflurane, although time to meeting discharge criteria was not different between the two groups. Emergence delirium occurs frequently with either technique.

Adolescent↗

PubMed1998

Paediatric preoperative teaching: effects at induction and postoperatively.

In a randomized controlled trial at Duke University and University of North Carolina Hospitals, 143 two to six year old children undergoing elective ambulatory surgery were randomized into a control group who received routine preoperative teaching or an intervention group who received an interactive teaching book. Changes in behaviour were measured by a Vernon behavioural questionnaire preoperatively and again two weeks postoperatively. A Global Mood Score was assessed in the preoperative holding area, at arrival into the operating room, and at the time of mask induction. The children in the control group were significantly more aggressive postoperatively than the intervention group (P < 0.05). Children who received the interactive teaching book exhibited higher levels of anxiety on the day of surgery, but fewer behavioural changes two weeks following surgery. Parents in the intervention group reported that preoperative teaching helped their child (87%) and themselves (83%).

Affect↗

PubMed1998

Evaluation of the accuracy and precision of lung aerosol deposition measurements from planar radionuclide imaging using simulation.

Planar images of known, theoretical distributions of radioaerosol in the lung have been simulated using lung models derived from magnetic resonance studies on human subjects. Total lung activity was evaluated from the simulated images together with the absolute penetration index (PI) and a relative value expressed as a fraction of that in a simulated ventilation image. The accuracy and precision of these measurements were calculated by comparison with the true values used in the simulation. Total activity was assessed with systematic errors within 5% and precision within 6.5%. Measured PIs varied only slowly with true PI and inter-model variation masked changes between measurements on the different distributions. The relative PI reduced inter-model variation and provided significant differences between all the distributions. PI was significantly affected by misalignment of the lung region of interest. The conducting airways deposition fraction (CADF) used in the simulation correlated linearly with the fractional activity in a central lung region, allowing CADF to be estimated with a precision of 21%.

Aerosols↗

PubMed1996

Assessment of deposition of inhaled aerosol in the respiratory tract of man using three-dimensional multimodality imaging and mathematical modeling.

Multimodality medical imaging enables measurement of the three-dimensional spatial distribution of a radiolabeled aerosol within the lung. Using a conceptual spatial morphological model these data may be transformed to provide information on deposition per airway generation. This methodology has been used to study the intrapulmonary deposition patterns of two formulations of a metered dose inhaler and two nebulizers in control subjects. The nebulizer study has also been stimulated using a computer model of deposition. The comparison between derived experimental results and those from computer modeling shows areas of agreement, although there are also areas of discrepancy. The new methodology has considerable potential value in the fields of inhalation therapy and deposition modeling, although more detailed validation is still required.

Administration, Inhalation↗

PubMed1996

Three-dimensional description of pulmonary deposition of inhaled aerosol using data from multimodality imaging.

UNLABELLED: Three-dimensional assessment of pulmonary deposition of inhaled aerosol may be performed using SPECT. The use of aligned anatomical images enables improved accuracy of quantification and anatomical localization of deposition. METHODS: Techniques of analyzing these data and their application to deposition studies of two nebulizer-generated aerosols (mass median diameter 1.5 and 6.5 microM respectively) in 12 normal subjects are described. The deposition data were transformed to a standard hemispherical shape and the mean distribution pattern for each aerosol evaluated. Deposition by airway generation was then calculated using a spatial model of airway morphology. The results were compared to those from planar image analysis. RESULTS: The hemispherical transform yielded considerably more qualitative information on deposition pattern. The central-to-peripheral concentration ratio between conducting and alveolated airways was 5.27 for the coarser aerosol and 2.43 for the fine. The two-dimensional spatial estimates of the ratio were 2.61 and 2.03 respectively. CONCLUSION: Analysis of multimodality imaging data considerably enhanced information on deposition compared to planar imaging. It provides new data on aerosol deposition which will be of value to physicians involved in drug inhalation therapy.

Aerosols↗

PubMed1994

Epidural morphine combined with epidural or intravenous butorphanol for postoperative analgesia in pediatric patients.

We performed a prospective, randomized, double-blinded study in 60 postoperative pediatric patients aged 6 wk to 7 yr to compare the efficacy of butorphanol given epidurally or intravenously in preventing the side effects of epidural morphine. Three groups of patients received 60 micrograms/kg epidural morphine; 20 patients also received epidural butorphanol 30 micrograms/kg, and 20 patients also received 30 micrograms/kg intravenous butorphanol. All patients were evaluated for analgesia, sedation, vomiting, urinary retention, pruritus, and respiratory depression for 24 h postoperatively. Although the overall incidence of side effects was not different in the three groups, the epidural butorphanol group had a significant decrease in severity of pruritus. Sedation was seen more frequently in the groups receiving butorphanol, but was most pronounced in the epidural butorphanol group. We conclude that butorphanol has little or no effect on the side effects of epidural morphine.

Butorphanol↗

PubMed1993

Epidural fentanyl infusion with patient-controlled epidural analgesia for postoperative analgesia in children.

The use of epidural fentanyl infusion with patient-controlled epidural analgesia (PCEA) is becoming popular for postoperative analgesia in adults. Its use has not been reported in the pediatric population. We report our initial experience with this technique in pediatric patients. The charts of all children who received epidural fentanyl infusions for postoperative analgesia between June 1991 and February 1992, were reviewed. Thirty-one patients, ages 6 to 17 years (mean +/- SD, 13.2 +/- 2.7) received epidural fentanyl infusion with PCEA for 36 operative procedures. Epidural catheters were either inserted in the lumbar (n = 14) or thoracic (n = 22) epidural space at a level based on the surgery. A fentanyl bolus of 1.38 +/- 0.43 micrograms/kg was delivered via epidural catheter just prior to the conclusion of surgery. A continuous infusion of fentanyl (0.56 +/- 0.18 micrograms/kg/h) with a PCEA bolus (0.53 +/- 0.17 micrograms/kg) available every 15 minutes was initiated in the recovery room and was utilized for 8 to 110 hours (59 +/- 27 hours). Pain and sedation were assessed by verbal descriptive scales, and side effects were noted. Alterations in dosing regimen were made for inadequate analgesia or side effects. Analgesia was assessed as excellent or good in 78% of the patients, 91% in the thoracic catheter group and 57% in the lumbar catheter group (P < .02). Patients with thoracic catheters were more likely to need their infusion and PCEA doses decreased, whereas those with lumbar catheters more often needed their doses increased (P < .05). No patient had respiratory depression.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

PubMed1993

Electrocardiographic and hemodynamic changes associated with unintentional intravascular injection of bupivacaine with epinephrine in infants.

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Anesthesia, Caudal↗

PubMed1992

Anaesthetic management of infants requiring endobronchial argon laser surgery.

Small infants with endobronchial lesions primarily due to traumatic suction catheter injuries are now undergoing argon laser surgery to remove obstructive tissue. Providing an anaesthetic for these infants can be challenging because of the small airways involved which must be shared by the anaesthetist and the surgeon. We have performed 30 argon laser endobronchial surgeries in nine infants. The lungs of the majority of patients were ventilated through a tracheostomy intraoperatively, while the surgeon passed the argon laser fibre through the suction port of a fibreoptic bronchoscope which was passed trans-nasally. Three infants were too small to allow passage of the fibreoptic bronchoscope past an artificial airway. In these patients surgery and ventilation were accomplished through a rigid bronchoscope. Three larger patients without tracheostomies were managed with a modified nasal airway for intraoperative ventilation in conjunction with the fibreoptic bronchoscope.

Airway Obstruction↗

PubMed1991

Intraoperative pacemaker failure in an infant.

Pacemakers in children can present clinical challenges during surgery. We present a case report of an infant whose pacemaker reverted to a backup mode when electrocautery was used during surgery. The resulting bradycardia did not respond either to a magnet placed over the generator or to iv atropine. The circulation was supported by isoproterenol until the pacemaker was re-programmed by the manufacturer. Such devices require care and understanding if problems during surgery are to be avoided.

Electrocoagulation↗

PubMed1991