Search PubMed⌕ Search

Biomedical subjects

D L Bourke

Publications and source records attributed to D L Bourke.

At least 37 records · Page 2Linked to original sources
PubMed1994

Endotracheal tube and tracheobronchial obstruction as causes of hypoventilation with high inspiratory pressures.

Two cases of difficult ventilation are presented, the first caused by endotracheal tube obstruction with nasal turbinate, and the second caused by tracheobronchial obstruction with blood clots. The clinical presentation in each case was characterized by extreme difficulty in ventilating and severe hypercapnia despite vigorous ventilatory efforts with either a mechanical ventilator or resuscitator bag. A simple manipulation of the endotracheal tube cuff helped to differentiate between increased impedance caused by endotracheal tube obstruction as opposed to increased respiratory system impedance beyond the tip of tube. In the second patient, in whom even a short interruption of ventilation was poorly tolerated, simultaneous rigid bronchoscopy (for removal of intratracheal masses) and ventilation via endotracheal tube were successfully performed.

Adult↗
PubMed1994

Treatment of a bronchopleural fistula with a Fogarty catheter and oxidized regenerated cellulose (surgicel).

A patient with bronchopleural fistula was successfully treated by occluding the fistula with an inflated Fogarty catheter balloon packed with oxidized regenerated cellulose (Surgicel) using a fiberoptic bronchoscope. After 48 h, the balloon was deflated, the fistula had sealed, and the patient did well. This simple and relatively noninvasive therapy was effective in this patient who was not a surgical candidate.

Aged↗
PubMed1993

Quantitative testing of sympathetic function with laser Doppler flowmetry.

OBJECTIVE: The objective of this study was to develop an indirect technique for evaluating dynamic changes in sympathetic function in humans. METHODS: We used laser Doppler to monitor sympathetic mediated vasoconstrictive responses (VRs) produced by 3 different provocative stimuli: 4-second inspiratory gasp (IG), ice-water immersion (Ice), and a spring-loaded pin prick (Pin). Skin perfusion on the thenar eminence was continuously monitored in 10 normal subjects (aged 25 to 36 years) using laser Doppler. Ten trials of the 3 stimuli were presented to each subject at 1-minute intervals. We determined the VR, the percent decrease in perfusion produced by each stimulus, and the 2 standard deviation variation in perfusion. RESULTS: No subject found the IG maneuver uncomfortable. In contrast, the Pin and Ice stimuli were reported to be uncomfortable by 8 and 10 subjects, respectively. Five subjects found Pin and Ice stimuli overtly painful. Vasoconstrictive response was 54.1 +/- 2.3% (mean +/- SEM) with IG, 49.2 +/- 2.0% with Ice, and 24.0 +/- 1.8% with Pin. Baseline variation was approximately 15% in all trials. CONCLUSION: Inspiratory gasp vasoconstrictive response (IGVR) is a sensitive indirect technique for evaluating sympathetic efferent function. We observed that the magnitude of the VR elicited by the IG stimuli was similar to that induced by cold water. Unlike the VR induced by Pin or Ice, IGVR is not dependent on noxious input via somatic afferents; therefore, it can be used in patients with diseases that produce a peripheral neuropathy, such as diabetes mellitus. Present uses of this technique and speculation on future uses are presented.

Adult↗
PubMed1993

Decimal dermatomes?

Explore the source record for details and available documents.

Anesthesia, Spinal↗
PubMed1993

The safety of intravenous phentolamine administration in patients with neuropathic pain.

The safety of intravenous (i.v.) infusion of large doses of phentolamine as an outpatient diagnostic tool for sympathetically maintained pain was studied retrospectively in 100 consecutive patients (73 females and 27 males) with chronic pain. All patients were pretreated with i.v. fluids followed, in most cases, by propranolol, 1-2 mg i.v. (n = 95). Ten minutes later the phentolamine infusion commenced, lasting for 20 min. In 90 patients, the dose of phentolamine was 35 mg. Two patients received 25 mg, and 8 patients received larger doses of 50-75 mg. No major complications occurred during or after the test, and only small changes in arterial blood pressure or heart rate were observed. All patients developed mild nasal stuffiness, but no decline in oxygen saturation was observed. Five patients developed one of the following minor complications for a brief duration, that resolved spontaneously: sinus tachycardia, premature ventricular beats, dizziness, or wheezing. We conclude that i.v. phentolamine administration is safe in patients with neuropathic pain.

Age Factors↗
PubMed1993

Time course of sympathetic blockade during epidural anesthesia: laser Doppler flowmetry studies of regional skin perfusion.

We studied the time course of sensory and sympathetic blockade in response to epidural local anesthetic test and bolus doses in 11 patients. Sympathetic activity was measured by monitoring cutaneous perfusion in the foot and the reflex vasoconstrictive response to deep inspiration (IGVR) using laser Doppler flowmetry. Sensory tests included the detection of touch, cold and painful stimuli. Following the 3-mL test dose perfusion increased to 192 +/- 38% (mean +/- SEM) of baseline (P < 0.05) in the patients with successful epidural anesthesia (9 of 11). In 8 of these patients, IGVR decreased to 73 +/- 10% of baseline (P < 0.05) within 6 min of the test dose, and preceded changes in sensation to cold, pin-prick, and light touch by 3.8 +/- 3.5 min (P < 0.2), 9.6 +/- 3.1 min (P < 0.01), and 11.6 +/- 2.7 min (P < 0.01), respectively. Five control patients who received only 60 mg of lidocaine intravenously and the two patients with failed epidurals did not show any perfusion or IGVR changes. This study confirms that sympathetic block precedes sensory block in sacral dermatomes after epidural anesthesia. Perfusion and IGVR changes are sensitive measures of sympathetic blockade and may predict successful epidural catheter placement.

Anesthesia, Epidural↗
PubMed1993

Assessment of ketorolac as an adjuvant to fentanyl patient-controlled epidural analgesia after radical retropubic prostatectomy.

BACKGROUND: Opioids, although effective postoperative analgesics, are associated with undesirable side effects. In an attempt to determine whether adjuvant, nonopioid medication would permit a reduction of the amount of fentanyl required for postoperative analgesia, the efficacy of ketorolac, an injectable nonsteroidal antiinflammatory drug, was studied as an adjuvant to fentanyl patient-controlled epidural analgesia (PCEA) for postoperative pain management following radical retropublic prostatectomy. METHODS: Forty patients were randomized into two groups to receive fentanyl PCEA and either ketorolac 30 mg intramuscularly every 6 h after an initial dose of 60 mg (n = 20) or placebo (n = 20) for 72 h. Visual analogue scale pain scores (0-100 mm; 0 mm = no pain; 100 mm = worst pain), sedation, fentanyl usage, gastrointestinal function, complications, blood loss, and temperature were assessed four times each day. RESULTS: Visual analogue scale (VAS) pain scores at rest were lower in the ketorolac group during the first 4 h (P < 0.01), but were similar thereafter. Global VAS pain scores with activity were lower in the ketorolac group on postoperative day 1 (23 +/- 4 vs. 39 +/- 6; P < 0.05) and postoperative day 2 (17 +/- 3 vs. 29 +/- 4; P < 0.05). Bladder spasm pain occurred less frequently in the ketorolac group (1 vs. 9 patients; P < 0.05). Fentanyl usage was less in the ketorolac group throughout the study (33 +/- 3 vs. 50 +/- 6 micrograms/h, 0-24 h; 20 +/- 2 vs. 36 +/- 6 micrograms/h, 24-48 h; 12 +/- 2 vs. 24 +/- 6 micrograms/h, 48-72 h; P < 0.05). Sedation scores and side effects were similar, except on postoperative day 3 when nausea was less frequent in the ketorolac group (0 vs. 6 patients; P < 0.05). Recovery of gastrointestinal function occurred sooner in the ketorolac group as determined by first bowel sounds (26 +/- 3 vs. 38 +/- 4 h; P < 0.05), first clear liquids (51 +/- 2 vs. 65 +/- 3 h; P < 0.01), and first regular meal (95 +/- 4 vs. 110 +/- 4 h; P < 0.05). There was no significant difference in blood loss, transfusion requirement, hematocrit, platelet count, or temperature. There was high overall satisfaction in both groups, but fewer patients in the ketorolac group rated pain with walking as usually or always painful (1 vs. 9 patients; P < 0.05). CONCLUSIONS: Ketorolac is a beneficial adjuvant to fentanyl PCEA for postoperative pain management after radical retropubic prostatectomy.

Analgesia, Epidural↗
PubMed1989

The steady-state and rebreathing methods compared during morphine administration in humans.

1. We examined the quantitative and qualitative differences between the steady-state and rebreathing methods of determining CO2-response curves before and after each of two doses of intravenous morphine (0.07 and 0.14 mg kg-1) in four healthy male humans. 2. During each study session steady-state and rebreathing CO2-response curves were determined as an ordered pair (separated by 15 min). Carbon dioxide-response curves were determined for control, after 0.07 mg kg-1 morphine, and after a total of 0.21 mg kg-1 morphine. Each subject was studied on a second occasion when the order of the CO2-response pairing was reversed. 3. The results are discussed and related to a model that may account for the differences based on the step increase in CO2 at the onset of rebreathing, the rate of rise of CO2 during rebreathing and the time constant for the central chemoreflex. 4. Our empirical conclusion is that morphine causes a parallel right shift of the steady-state CO2-response curve and causes a non-specific decrease in the slope of the rebreathing CO2-response curve. We suggest that the parallel shift of the steady-state CO2-response curve is specific to drugs acting on opioid receptors.

Adult↗
PubMed1988

Spontaneous regeneration of older dystrophic muscle does not reflect its regenerative capacity.

Young dystrophic (dy) murine muscle is capable of "spontaneous" regeneration (i.e., regeneration in the absence of external trauma); however, by the time the mice are 8 weeks old, this regeneration ceases. It has been suggested that the cessation of regeneration in dystrophic muscle may be due to exhaustion of the mitotic capability of myosatellite cells during the early stages of the disease. To test this hypothesis, orthotopic transplantation of bupivacaine treated, whole extensor digitorum longus muscles has been performed on 14 to 16-week-old 129 ReJ/++ and 129 ReJ/dydy mice. The grafted dystrophic muscle is able to produce and maintain for 100 days post-transplantation 356 +/- 22 myofibers, a number similar to that found in age-matched dystrophic muscle. The ability of old dystrophic muscle to regenerate subsequent to extreme trauma indicates that the cessation of "spontaneous" regeneration is due to factor(s) other than the exhaustion of mitotic capability of myosatellite cells. Moreover, there is no significant difference in myosatellite cell frequencies between grafted normal and dystrophic muscles (100 days post-transplantation). Myosatellite cell frequencies in grafted muscles are similar to those in age-matched, untraumatized muscles. While grafting of young dystrophic muscle modifies the phenotypic expression of histopathological changes usually associated with murine dystrophy, grafts of older dystrophic muscle show extensive connective-tissue infiltration and significantly fewer myofibers than do grafts of age-matched normal muscle. As early as 14 days post-transplantation, it is possible to distinguish between grafts of old, normal and dystrophic muscles. It is suggested that the connective tissue stroma, present in the dystrophic muscle at the time of transplantation, may survive the grafting procedure.

Age Factors↗