Biomedical subjects

O Gall

Publications and source records attributed to O Gall.

5 recordsLinked to original sources

PubMed1998

Addition of clonidine or fentanyl to local anaesthetics prolongs the duration of surgical analgesia after single shot caudal block in children.

Caudal anaesthesia is indicated for surgical procedures lasting less than 90 min. Fentanyl and clonidine are known to prolong postoperative caudal analgesia, but there are no data on their effect on duration of surgical analgesia. We evaluated if the addition of clonidine or fentanyl to local anaesthetics prolonged the duration of surgical analgesia after single shot caudal block in children in a randomized, double-blind study. We studied 64 children, aged 6-108 months, undergoing bilateral correction of vesicoureteral reflux which was expected to last more than 90 min. Patients were allocated to one of four groups: group O received 1 ml kg-1 of a mixture of 0.25% bupivacaine with epinephrine and 1% lidocaine in equal parts; group F received the same mixture of local anaesthetics in addition to fentanyl 1 microgram kg-1; group C received the same mixture of local anaesthetics in addition to clonidine 1.5 micrograms kg-1; and group C + F received the same mixture of local anaesthetics in addition to fentanyl 0.5 microgram kg-1 and clonidine 0.75 microgram kg-1. Single shot caudal block was sufficient in only 57% of children in group O compared with 93% in groups C and F and 86% in group C + F (P = 0.035). Global assessment of anaesthesia, defined as the time from caudal injection to the first administration of analgesic (either during or after surgery), was significantly longer in the three groups of children who received additives compared with local anaesthetics alone (P = 0.035), but there were no differences between the three additive groups. Vomiting was observed only in children who received fentanyl. Addition of clonidine or fentanyl to local anaesthetics prolonged the duration of surgical analgesia of caudal block, allowing single shot caudal anaesthesia to be recommended for surgery lasting 90-150 minutes. Clonidine had some advantages over fentanyl as it did not produce clinically significant side effects.

Adrenergic alpha-Agonists↗

PubMed1998

Involvement of the caudal medulla in negative feedback mechanisms triggered by spatial summation of nociceptive inputs.

In the rat, applying noxious heat stimuli to the excitatory receptive fields and simultaneously to adjacent, much larger, areas of the body results in a surface-related reduction in the responses of lumbar dorsal horn convergent neurons. These inhibitory effects induced by spatial summation of nociceptive inputs have been shown to involve a supraspinally mediated negative feedback loop. The aim of the present study was to determine the anatomic level of integration of these controls and hence to ascertain what relationships they might share with other descending controls modulating the transmission of nociceptive signals. The responses of lumbar convergent neurons to noxious stimulation (15-s immersion in a 48 degrees C water bath) applied to increasing areas of the ipsilateral hindlimb were examined in several anesthetized preparations: sham-operated rats, rats with acute transections performed at various levels of the brain stem, and spinal rats. The effects of heterotopic noxious heat stimulation (tail immersion in a 52 degrees C water bath) on the C-fiber responses of these neurons also were analyzed. The electrophysiological properties of dorsal horn convergent neurons, including their responses to increasing stimulus surface areas, were not different in sham-operated animals and in animals the brain stems of which had been transected completely rostral to a plane -2. 8 mm remote from interaural line (200 micron caudal to the caudal end of the rostral ventromedial medulla). In these animals, increasing the stimulated area size from 4.8 to 18 cm2 resulted in a 35-45% reduction in the responses. In contrast, relative to responses elicited by 4.8 cm2 stimuli, responses to 18 cm2 were unchanged or even increased in animals with transections at more caudal level and in spinal animals. Inhibitions of the C-fiber responses elicited by heterotopic noxious heat stimulation were in the 70-80% range during conditioning in sham-operated animals and in animals with rostral brain stem transections. Such effects were reduced significantly (residual inhibitions in the 10-20% range) in animals with transections >500 micron caudal to the caudal end of the rostral ventromedial medulla and in spinal animals. It is concluded that the caudal medulla constitutes a key region for the expression of negative feed-back mechanisms triggered by both spatial summation of noxious inputs and heterotopic noxious inputs.

Animals↗

PubMed1997

Video-assisted thoracoscopic surgery for right middle lobectomy in children.

This case-control study was designed to evaluate the potential advantages and disadvantages of video-assisted thoracoscopic surgery for right middle lobectomy in children. Ten children (6.1 +/- 3.0 yr, mean +/- SD) who underwent right middle lobectomy under videoscopy were compared with 10 controls matched for age (6.8 +/- 3.5 yr) and operated by thoracotomy (muscle-sparing technique) during the same period by the same surgeon. Operating time was significantly longer in the videoscopy group than in the thoracotomy group (146 +/- 28 mn vs 100 +/- 27 mn, P < 0.001). Minimum oxygen saturation values were significantly higher in the videoscopy group whereas oxygen requirements did not differ between groups. Incidence of postoperative respiratory complications (mainly atelectasis) was similar in the two groups. No difference in postoperative analgesic requirements in the postoperative period was demonstrated. No real benefit or disadvantage of videoscopy over standard thoracotomy could be observed in this retrospective case-control study.

Anesthesia, General↗

PubMed1995

[Latex hypersensitivity: a foreseeable accident?].

This paper describes another case of severe anaphylactic reaction due to allergy to natural rubber during anaesthesia in a child without known risk factors. The day after surgery the child reported that he experienced a few months ago an impressive skin reaction of both face and lips after inflating a latex balloon. It is suggested to try to detect latex allergy during the preoperative visit in all patients by including questions about latex sensitivity such as previous skin reactions or respiratory symptoms after wearing latex gloves or after inflating toy balloons. Patients in whom latex sensitivity is suspected should be tested appropriately in order to perform the planned surgery in a latex-free environment.

Adolescent↗

PubMed1992

Priming doses of atracurium and vecuronium depress swallowing in humans.

The administration of low doses of muscle relaxant may cause peripheral muscular weakness including difficulty in swallowing. In the present study, the effect of priming doses of atracurium and vecuronium on swallowing was studied. Sixty patients undergoing elective surgery under general anesthesia were divided randomly into four groups of 15 patients and received as a priming dose either vecuronium (10 or 15 micrograms/kg) or atracurium (50 or 75 micrograms/kg). Swallowing muscle activity was measured by electromyography using submental surface electrodes. Swallowing was initiated by administration of 0.3 ml distilled water through an oral catheter. Swallowing reflex was determined by measuring the latency time (i.e., time from water administration to start of EMG activity of glossal muscles). Swallowing activity was determined by integration of the EMG of glossal muscles during swallowing. Peripheral muscle strength was determined by hand grip strength. Swallowing reflex activity and peripheral muscle strength were measured before and 3 and 6 min after administration of vecuronium or atracurium. Latency time remained unchanged after any of the priming doses. Integrated EMG decreased significantly (P < .001) 3 and 6 min after all priming doses tested (42-75% of baseline value). Only after atracurium 75 micrograms/kg was the hand grip strength significantly decreased (P < .01). These results suggest that owing to its effect on swallowing, the priming dose should be used with caution.

Adult↗