PubMed Health⌕ Search

Biomedical subjects

A Palmer

Publications and source records attributed to A Palmer.

At least 127 records · Page 7Linked to original sources
PubMed1989

Repair of the isolated cut flexor digitorum profundus tendon under intravenous regional anaesthesia.

Intravenous regional anaesthesia proved to be an effective anaesthetic agent for the repair of isolated cut flexor digitorum profundus tendons. Twenty-five patients underwent primary repair, of whom 20 were assessed 1 year later. Overall results were satisfactory regarding movement at the distal joint. Five of the cases were missed at initial examination and the repair carried out longer than 1 week from the injury. In view of the generally accepted poor initial diagnosis in the Emergency Department for the isolated flexor tendon lesion, exploration under a simply performed local anaesthetic block has advantages where the diagnosis is in doubt. The main operative problem with this technique was the venous ooze which occurred during the operation, and this could be a contraindication to its use for more complicated hand surgery.

Anesthesia, Conduction↗
PubMed1989

Ablation of ventricular tachycardia of right ventricular origin with low energy shocks.

Three shocks of 2 joules (2,000 volts within 0.3 msec) were given to a patient with ventricular tachycardia of right ventricular origin at the site of the earliest activation. A standard 6 Fr USCI mapping catheter was used. After the first shock the cycle length prolonged from 385 to 531 msec. After the second shock, the tachycardia was no longer inducible and it remained so after 1 week. No recurrences were seen during a follow-up period of 8 months. This is the first report demonstrating efficacy of modified low energy shocks for ventricular tachycardia.

Electric Countershock↗
PubMed1989

Lasers for otosclerosis: CO2 vs. Argon and KTP-532.

The concept of using laser energy to perform stapedotomy and stapedectomy revision is an attractive one. Precision of vaporizing a perfectly round 0.6- to 0.8-mm hole in the stapes footplate, regardless of its thickness or degree of fixation, would introduce an elegant simplicity to a sometimes difficult operation while eliminating mechanical trauma to the inner ear. When revising a previously failed stapedectomy, lasers should enable the otologic surgeon to atraumatically vaporize the obliterating oval window tissue and thus precisely diagnose the cause of the failure. A laser stapedotomy could then be performed in the membranous oval window, thus minimizing the risk of recurrent prosthesis migration. To accomplish these objectives, lasers must possess physical properties which permit the precise controlled delivery of laser energy to the microscopic operative field. Tissue characteristics of this laser energy should permit the vaporization of the stapes footplate or oval window soft tissue without thermal effect to the vestibule and without passing through the perilymph to damage the delicate structures of the inner ear. Two types of lasers have been successfully used for otosclerosis surgery: the visible lasers (Argon and KTP-532) and the invisible CO2 laser. This paper explores relative merits and disadvantages of each. The visible lasers possess ideal optical properties for microsurgery and, until recently (1984), were the only group of lasers optically precise enough for safe use on the oval window. Unfortunately, the short wavelength of these visible lasers (0.5 mu) impart tissue properties which are less than ideal for otosclerosis surgery. Visible laser is only partially absorbed by the white stapes footplate and readily passes through the perilymph to be absorbed by pigmented tissue of the inner ear (blood vessels, neuroepithelium, etc.). Therefore, the Argon and KTP-532 lasers should be used with caution while performing stapedotomies. Visible lasers should not be used for stapedectomy revisions since direct application of visible laser energy to the open vestibule produces dramatic temperature rises (up to 175 degrees C) in the vestibule at the level of the utricle and saccule. The long wavelength of the invisible CO2 laser (10.6 mu) imparts many optical problems which limit its precision for microscopic surgery. Until recently, the CO2 laser was too inaccurate for otosclerosis engineering advances for CO2 microsurgery. A newly designed microslad optical delivery system could deliver a 0.3-mm spot size CO2 beam at 250-mm focal length which was satisfactorily par-focal and coaxial with the aiming HeNe beam.(ABSTRACT TRUNCATED AT 400 WORDS)

Argon↗
PubMed1989

CO2 laser for otosclerosis: safe energy parameters.

Safe energy parameters for each Sharplan CO2 laser model (734, 1040, 1100A) were established in the laboratory. Ultrasensitive pyroelectric detectors analyzed the precise energy package delivered to the operative field with each of these power setting. Subsequently, 0.6-mm stapedotomy and stapedectomy revisions were performed under simulated operating room conditions while measuring temperature changes in the vestibule with a thermocouple. Table I illustrates safe energy settings for each of the Sharplan CO2 models tested. These power settings produced no more than 0.3 degrees C temperature rise in the vestibule during stapedotomy, and no more than 0.5 degrees C during stapedectomy revision. Following these guidelines, the CO2 laser was then employed to perform stapedotomy and stapedectomy revisions in otosclerosis patients. In over 200 consecutive operations performed under local anesthesia with the CO2 laser, no patient became dizzy intraoperatively while the CO2 laser was applied to the stapes footplate or the oval window neomembrane, confirming the lack of significant caloric effect to the inner ear at these energy settings. More importantly, no patient has yet experienced significant sensorineural hearing loss in the speech range.

Carbon Dioxide↗
PubMed1989

Alternating capture of the ventricle and an unusual pacing rate.

The recent improvements in technology of cardiac pacing are often responsible for difficult electrocardiograms at follow-up (Gladstone et al., 1987). Therefore, it seems an advantage that most modern pacemakers include diagnostic software functions to explain the pacing behaviour (event markers, intracardiac electrograms...). In this case report an electrocardiogram, showing pacing dysfunction of a physiologic pacemaker with rate response is presented. It was possible to understand what was happening without electrograms, but confirmation of our interpretation of the pacing behaviour was only possible with telemetric data.

Aged↗
PubMed1988

Expression of chromosome 21 specific sequences in normal and Down's syndrome tissues.

Using RNA isolated from age and sex matched normal and Down's Syndrome foetal liver and brain tissues, Northern blots were prepared and probed with 4 chromosome 21 specific sequences. The results show that no consistent pattern of expression emerges when Down's Syndrome tissue is compared with normal tissue but the results are very different from the 3/2 ratio of expression which may be expected. Two sequences 21.3 and 26C show only minor differences in expression in trisomy 21 liver samples but significant changes in their expression pattern when normal and Down's Syndrome brain samples are compared. The other sequences, JG77 and JG90 show a 5 fold higher degree of expression in Down's brain but when liver samples are compared one of these sequences shows equal levels of expression in normal and Down's Syndrome samples and the other shows a decrease in expression level in Down's Syndrome samples.

Animals↗
PubMed1988

Method for removal of the St. Jude valve.

A method is presented for removal of the St. Jude Medical valve when it must be replaced with another prosthesis. The sewing ring is transected in the radial direction, freeing the rigid portion of the valve. This is then removed, allowing the remainder of the sewing ring to be excised under direct vision. This method simplifies and increases the safety of this procedure.

Heart Valve Prosthesis↗
PubMed1987

Red cell antibodies.

Explore the source record for details and available documents.

Blood Group Antigens↗
PubMed1986

Effect of DC-shocks of 400 Joules on the AV-node.

Ablation of the AV-node with direct current shocks and 6-French U.S.C.I. catheters was performed in 8 patients with disabling supraventricular arrhythmias. An initial shock of 400 Joules was chosen in most instances. In all patients transient or permanent complete AV-block was obtained. For one patient the procedure was considered a failure, after three sessions. Five patients remain in complete AV-block. Average escape rhythm at first ambulatory follow-up was 47 bpm. The block seems to be situated at the level of the bundle of His, or distal of this level. The other two patients are clinically improved with impaired AV-conduction. A pacemaker was implanted in all patients.

Aged↗