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Biomedical subjects

J C Stuart

Publications and source records attributed to J C Stuart.

At least 19 recordsLinked to original sources
PubMed2000

Alfentanil given immediately before the induction of anesthesia for elective cesarean delivery.

Opioids are routinely omitted at the induction of general anesthesia for cesarean delivery because of concerns about neonatal respiratory depression. The subsequent unmodified maternal stress response to tracheal intubation reduces placental perfusion. The short-acting opioid alfentanil may afford advantages at the induction, without subsequent neonatal depression. In this double-blinded study of elective cesarean deliveries, 40 patients were allocated randomly to receive either alfentanil 10 microg/kg (n = 18) or placebo (n = 22), 1 min before the induction of anesthesia with thiopental 4 mg/kg and succinylcholine 1.5 mg/kg. Anesthesia was maintained with 50% nitrous oxide, 0.5% isoflurane in oxygen, and atracurium. Neonates were assessed by using Apgar scores, Neurologic and Adaptive Capacity Scores, and umbilical cord blood gas and catecholamine analysis. After intubation, mothers receiving alfentanil had a smaller increase in mean arterial blood pressure, (11 +/- 15 vs 31 +/- 13 mm Hg, P < 0.001) and lower plasma norepinephrine concentrations, (336 +/- 152 vs 486 +/- 241 pg/mL, P < 0.05). Neonates in the alfentanil group had greater umbilical arterial oxygen tensions (27.8 +/- 7.0 vs 22.6 +/- 7.4 mm Hg), slightly reduced Apgar scores (both P < 0.05), but similar Neurologic and Adaptive Capacity Scores. One neonate in the alfentanil group required naloxone. The maternal stress response was attenuated in the alfentanil group but at the cost of early neonatal depression. However, all neonates should be monitored for possible immediate, but transient, respiratory depression.

Adult↗
PubMed1996

A comparison of the haemodynamic effects of intrathecal meperidine, meperidine-bupivacaine mixture and hyperbaric bupivacaine.

PURPOSE: To study the haemodynamic effects of intrathecal meperidine, administered either alone or mixed with bupivacaine. METHODS: We studied 42 Chinese patients, aged 59-87 yr, scheduled for transurethral bladder or prostate surgery, randomized into three equals groups, that received either meperidine 0.8 mg.kg-1, meperidine 0.4 mg.kg-1 plus 1.5 ml of 0.5% heavy bupivacaine or 3 ml of heavy bupivacaine 0.5%. Non-invasive systolic (SAP) and mean (MAP) arterial pressures, central venous pressure and cardiac index, stroke index and heart rate (HR) measured by the BoMed NCCOM3-R7S bioimpedance device, were recorded over the first 25 min. Systemic vascular resistance index (SVRI) was derived. Onset of sensory and motor block was also measured. Decreases in MAP of 25% were treated with colloid and metaraminol. RESULTS: The onset of block was slower in the meperidine group (P < 0.05). Decreases in SAP, MAP and SVRI (all; P < 0.001) occurred within five minutes in all three groups. The HR was increased in the bupivacaine group (P = 0.03), but bradycardias treated with atropine occurred in six patients receiving meperidine and four patients receiving the mixture. Six patients receiving meperidine and two patients receiving the mixture required general anaesthesia for inadequate block. The incidence of nausea and vomiting was higher in the patients receiving meperidine (P < 0.05). No other complications were encountered. CONCLUSIONS: Intrathecal meperidine used alone or mixed with bupivacaine has no intra-operative advantage over heavy bupivacaine 0.5%.

Aged↗
PubMed1996

Acid aspiration prophylaxis for emergency Caesarean section.

Over a 3.5 year period, 384 patients requiring emergency Caesarean section under general anaesthesia received at random one of six acid aspiration prophylaxis regimens as soon as the decision was made for surgery. In the first phase of the study, sodium citrate administered orally 0.3 M, 30 ml (group C, n = 120) was compared with metoclopramide 10 mg administered intravenously and sodium citrate (group MC, n = 65). In the second phase, all patients received sodium citrate, and either intravenous administration of ranitidine 50 mg (group RC, n = 50), omeprazole 40 mg (group OC, n = 50), ranitidine 50 mg with metoclopramide 10 mg (group RMC, n = 50) or omeprazole 40 mg with metoclopramide 10 mg (group OMC, n = 49). Gastric contents were aspirated using a 16 FG Salem sump tube and acidity measured with a pH meter. Non-parametric tests were used for comparisons. There was no difference in gastric volume or pH between groups C and MC, or among OC, RC, OMC and RMC. After pooling the data, median (range) gastric volume in groups C and MC (55 (0-360) ml) was greater than in groups OMC and RMC (40 (3-270) ml, p < 0.05). Median (range) pH was lower in groups C and MC (4.97 (0.76-6.99)) than in groups OC, RC, OMC and RMC (5.76 (1.11-7.5), p < 0.001). The proportion of patients with pH < 3.5 and volume > 25 ml in the C and MC groups (43/185) was greater than that in the OC, RC, OMC and RMC groups (18/199, p < 0.001). Ranitidine and omeprazole administered intravenously were equally effective adjuncts to sodium citrate in reducing gastric acidity for emergency Caesarean section. Compared with sodium citrate alone, the addition of either ranitidine, omeprazole or metoclopramide alone did not reduce gastric volume while small reductions in gastric volume were seen with the addition of metoclopramide and either ranitidine or omeprazole.

Adult↗
PubMed1995

Hypotension during subarachnoid anaesthesia: haemodynamic effects of ephedrine.

We have compared the haemodynamic effects of ephedrine alone with ephedrine and colloid for the treatment of hypotension produced by subarachnoid anaesthesia in 30 patients aged 60-90 yr with fractures of the neck of femur. Group one received ephedrine as an initial bolus dose of 0.2 mg kg-1 followed by an infusion of 0.5 mg kg-1 h-1. Group two received ephedrine and colloid (polygeline, Haemaccel) 8 ml kg-1. If necessary, up to three rescue bolus doses of ephedrine (0.1 mg kg-1) and then colloid solution (8 ml kg-1) were given to maintain systolic arterial pressure (SAP) at > 75% of baseline. Arterial pressure was measured by automated oscillotonometry, central venous pressure (CVP) by a manometer and cardiac index (CI), stroke index (SI) and heart rate (HR) by transthoracic electrical bioimpedance. Systemic vascular resistance index (SVRI) was derived. In patients receiving ephedrine only, SVRI, CVP and SI decreased and HR increased (P < 0.0001). Five patients in this group required colloid, the effect of which was to restore CVP, increase CI and SI, and decrease HR (P < 0.02). In patients receiving ephedrine and colloid solution, SVRI decreased and CI, SI and HR increased (P < 0.0001). Ephedrine was not a potent arterial vasoconstrictor and SAP was maintained mainly by increases in SI and HR.

Aged↗
PubMed1995

Anaesthesia in an infant with Rubinstein-Taybi syndrome.

The anaesthetic management of a 5-month-old Chinese infant with Rubinstein-Taybi syndrome requiring bilateral inguinal hernia repairs is described. This is a rare congenital syndrome characterised by mental retardation, broad thumbs and first toes, craniofacial abnormalities, recurrent respiratory infections and, in one third of cases, congenital heart disease. General anaesthesia combined with caudal block was successfully used. The main complications encountered were minor difficulties with intubation and easily precipitated episodes of oxygen desaturation.

Anesthesia, Caudal↗
PubMed1994

Haemodynamic effects of subarachnoid block in elderly patients.

We have studied the haemodynamic effects of subarachnoid block in elderly patients. Thirty patients were undergoing elective transurethral surgery and 18 non-elective orthopaedic surgery, predominantly fractured neck of femur. Systolic arterial pressure (SAP) was measured by automated oscillotonometry, central venous pressure (CVP) by manometer and cardiac index (CI), stroke index (SI) and heart rate (HR) by transthoracic electrical bioimpedance. Systemic vascular resistance index (SVRI) was derived. SAP decreased by more than 25% in 33 patients and SVRI showed similar decreases (P = 0.0001). CVP decreased (2.5 (SD 1.5) cm H2O) in all patients. CI was unaffected because a decrease in SI in some patients (13 (19)%; P = 0.01) was compensated for by an increase in HR (13 (13)%; P = 0.01). Decreases in SAP of 25% were treated initially with colloid solution 8 ml kg-1, which restored SAP in 19 patients. CVP, SI and HR were all restored to baseline values, however, SVRI was decreased further (P < 0.05). Fourteen patients required additional treatment with metaraminol which restored SVRI to baseline values. Patients with systolic hypertension were more likely to require treatment with metaraminol (P = 0.04).

Aged↗
PubMed1994

Peritonsillar infiltration with bupivacaine for paediatric tonsillectomy.

In a double-blind study forty-two children scheduled for elective adenotonsillectomy were randomized to receive peritonsillar infiltration, following induction of anaesthesia, with either 0.25% plain bupivacaine or 0.9% saline, 0.5 ml/kg to a maximum of 10 ml. The children were assessed on awakening, and then 10 minutes, 1 hour, 4 hours and 24 hours later. On each occasion the observer gave the child a pain score from 1 (no pain) to 5 (severe pain). The scores on awakening and after 10 minutes were significantly lower in the bupivacaine group (P < 0.05, Mann-Whitney U test). Thereafter there was no difference between the groups. The authors conclude that peritonsillar infiltration with bupivacaine is only moderately useful as analgesia for children having tonsillectomy.

Analgesia↗
PubMed1991

Aprotinin treatment of pseudomonal corneal infection.

Pseudomonas aeruginosa produces proteolytic enzymes capable of causing severe corneal degradation. In this study we tested aprotinin, a broad-spectrum protease inhibitor, on rabbit corneas infected with P. aeruginosa to determine whether any benefit could be derived. Corneas treated with aprotinin and tobramycin topically and subconjunctivally were not clinically better than corneas treated with tobramycin alone.

Administration, Topical↗
PubMed1990

Temporal changes in posterior capsulotomy dimensions following neodymium:YAG laser discission.

We prospectively evaluated 20 eyes of 19 consecutive patients to determine the nature of temporal changes in posterior capsulotomy size, shape, and contour six weeks following neodymium:YAG laser posterior capsular disruption. Mean capsulotomy area increased by 32% (range 0 to 134%, P less than .05, Student t-test), although mean capsulotomy perimeter did not change appreciably. Capsular enlargement tended toward sphericity over time, with smoothing of edge contour from capsular tag retraction. Remodeling of opening size, shape, and contour was most likely to occur with preoperative evidence of capsular traction, and highly irregular capsulotomy borders immediately post-discission.

Aged↗
PubMed1985

Antifungal synergism. A proposed dosage for corneal storage medium.

Fungal infections from eye bank-preserved corneas have led us to search for antifungal agents that will eliminate yeast and mold in McCarey-Kaufman (MK) medium and concurrently be nontoxic. Amphotericin B, natamycin, nystatin, and clotrimazole were tested in synergistic combinations in vitro against nine yeast and six mold specimens. For average yeast and mold concentrations of 3.4 X 10(4) and 1.36 X 10(4) colony-forming units (CFUs)/mL at 5 degrees C, and 3.36 X 10(4) and 2.3 X 10(3) CFUs/mL at 37 degrees C, respectively, a synergistic combination of all four drugs at one twelfth the minimal fungicidal concentrations proved fungicidal. This synergistic combination did not alter donor human corneal morphology under specular microscopy, nor did it inhibit rabbit corneal endothelial cell division preserved and propagated in antifungal supplemented MK medium. The synergistic drug mixture did prove to be fungicidal when the endothelial cells were challenged with fungal inoculum.

Amphotericin B↗
PubMed1985

Dilute sodium hyaluronate (Healon) in the treatment of ocular surface disorders.

The use of dilute (1/10%) sodium hyaluronate (Healon) eyedrops has given definite subjective patient improvement in a variety of ocular surface disorders, especially keratitis sicca. No adverse effects of the sodium hyaluronate drops have been encountered in patients who have used the drops for as long as two years. Masked trials and objective improvement of corneal staining patterns have also confirmed its efficacy.

Contact Lenses↗