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Biomedical subjects

J M Hunter

Publications and source records attributed to J M Hunter.

At least 91 records · Page 5Linked to original sources
PubMed1991

Recurrent carpal tunnel syndrome, epineural fibrous fixation, and traction neuropathy.

This article has reviewed recurrent carpal tunnel syndrome, epineural fibrous fixation, and traction neuropathy of the median nerve. The problems surrounding the diagnosis and treatment of recurrent CTS have been discussed at length. The percent of failures from traditional open ligament surgery is observed to be high, and will become more prevalent as more casual treatments are carried out. This article makes a positive statement with reference to mobilization of the median nerve and anatomic restoration of the transverse carpal ligament. Fibrous fixation of the median nerve is a product of life and function. All cases are different, reflecting the strength, abilities, and personalities of the patients. A bottom line is drawn on these patients, where the summation of the problems of life become symptomatic and disabling. Epineural fibrous fixations induce median nerve traction, governed by hand, wrist, and forearm movements. Traction and tension suggest the intermittent disturbance of nerve nutrition and nerve conduction as the elastic limits of the nerve are approached. These factors accumulate and, in time, cause traction neuropathies with pain. This is followed by a reduced work capability. This impairment can be reversed by surgical nerve mobilization followed by functional nerve gliding therapy. A background history injury to the hand and wrist may be significant, as well as factors such as overuse and misuse of the hand and extremity. Prior to surgery, the careful application of diagnostic stress tests are essential, for the differential diagnosis of fixation traction and positional peripheral neuropathies. Nerve mobilization supported by magnification and the techniques of hand surgery has been successful by the methods discussed and has permitted, importantly, the restoration of the anatomic retinaculum for the flexor tendon system. This can be restored in carpal tunnel surgery and reconstructed with basic ligament material in recurrent carpal tunnel surgery.

Aftercare↗
PubMed1991

Dacron stabilization of the distal ulna.

The pronator lock procedure offers an alternative to the treatment of chronic, symptomatic dorsal translation of the distal ulna in pronation. The porous Dacron tendon has been a useful adjunct and has obviated the need for free tendon grafts, intact tendon slips, or fascia lata in the construction of the radioulnar tether. Careful clinical and biomechanical evaluation of the technique and material is required and is currently under investigation.

Chronic Disease↗
PubMed1991

Superficialis finger reconstruction: a new look at a last-resort procedure.

The anatomic two-tendon, three-joint finger cannot always be restored to normal after a severe flexor tendon injury. An effective alternative to consider is reconstruction of superficialis finger function or one-tendon to two-joint function. This principle has been applied to two-stage flexor tendon reconstruction in severe salvage situations to provide a good working arc of digital flexion. The surgical procedure, postoperative considerations, and biomechanical principles are discussed.

Finger Injuries↗
PubMed1991

Collateral ligament reconstruction of the metacarpophalangeal and proximal interphalangeal joints using porous dacron tendon.

We are encouraged by the favorable preliminary results of ligamentous reconstruction using the porous Dacron tendon. It provides a stable construct in cases where there is insufficient local autogenous tissue, and obviates the need for a tendon graft. Early active range of motion is permitted. Current investigation for additional applications for the use of the porous Dacron tendon include volar plate reconstruction following disruption, capsuloligamentous reconstruction of the trapezial metacarpal joint (with trapezium implant arthroplasty as well as for isolated disruption of the volar oblique ligament), intercarpal ligament repair or augmentation, and distal radioulnar joint stabilization.

Arthritis↗
PubMed1991

Therapeutic techniques to enhance nerve gliding in thoracic outlet syndrome and carpal tunnel syndrome.

By studying capabilities inherent in the nerve proper and carefully considering patient complaints and limitations, the surgeon-therapist team may be able to guide patients through a restorative phase via nerve gliding techniques. Nerve symptoms must be heeded when employing rehabilitation techniques. Rather than encouraging the patient to push beyond nerve pain either proximally or distally, the patient is instructed to perform exercises in positions that enhance nerve gliding in a slow, controlled manner. "Tincture of time" is prescribed as the patient advances to a less symptomatic level of function.

Brachial Plexus↗
PubMed1990

The community perinatal health care system of urban Cape Town, South Africa--I. Characteristics of mothers and birth outcomes.

Greater Cape Town has developed a geographical network of perinatal health care services for low-income mothers using community-based clinics with hospital referrals. This study analyzes 25,409 births recorded in 162 different urban residential areas during 1987. The data apply to two populations--black and mixed. Information on the mother, such as height, weight, education, parity, and prenatal visits is indicated by suburb, as well as birth outcomes such as gestational age, birthweight, and method of obstetrical delivery. Comparisons are drawn between black and mixed populations and among suburbs. High utilization rates and successful maternity and infant outcomes suggest that the outreach clinics of Cape Town could provide a model for urban agglomerations in other African countries.

Adolescent↗
PubMed1990

The community perinatal health care system of urban Cape Town, South Africa--II. Geographical patterns.

Greater Cape Town has developed a geographical network of perinatal health care services for low-income mothers using community-based clinics with hospital referrals. This study analyzes 25,409 births recorded in 162 different urban residential areas during 1987. The data apply to two populations--black and mixed. Information on the mother, such as height, weight, education, parity, and prenatal visits is indicated by suburb, as well as birth outcomes such as gestational age, birthweight, and method of obstetrical delivery. Comparisons are drawn between black and mixed populations and among suburbs. High utilization rates and successful maternity and infant outcomes suggest that the outreach clinics of Cape Town could provide a model for urban agglomerations in other African countries.

Adolescent↗
PubMed1990

Limited value of technetium 99m-labeled red cell scintigraphy in localization of lower gastrointestinal bleeding.

The aim of this study was to assess the accuracy of technetium 99m-labeled red cell scintigraphy in localizing the site of lower gastrointestinal bleeding. The outcome of 203 patients undergoing technetium 99m-labeled red cell scintigraphy was reviewed, and the scan result was compared with the true site of bleeding. The true site of bleeding was determined by other methods including angiography and surgical pathology. Fifty-two scans (26%) were positive and indicated a specific site of bleeding. A definitive bleeding site was identified in 22 patients by other means and correlated with the technetium scan in only 9 cases. The nuclear scan was incorrect in the remaining 13 cases, implying a localization error of 25% (13 of 52). A subgroup of 19 patients with a positive scan underwent a surgical procedure directed by the nuclear scan. Eight of these 12 patients had incorrect surgical procedures based upon findings of more definitive tests, indicating a surgical error of 42% (8 of 19). We conclude that the technetium 99m-labeled red cell scan's ability to accurately localize the site of lower gastrointestinal bleeding is limited. Furthermore, performing a surgical procedure that relies exclusively on localization by red cell scintigraphy will produce an undesirable result in at least 42% of patients.

Aged↗
PubMed1989

Pharmacokinetics of atracurium and laudanosine in patients with hepatic cirrhosis.

The pharmacokinetic profiles of atracurium and one of its derivatives, laudanosine were studied following an i.v. bolus of atracurium 0.6 mg kg-1 administered to eight patients with hepatic cirrhosis and to seven healthy controls. The central volume of distribution of atracurium was greater in the patients with cirrhosis (104.6 ml kg-1) compared with the controls (69.6 ml kg-1) (P less than 0.05), as was the total volume of distribution (281.8 ml kg-1 and 202.1 ml kg-1, respectively) (P less than 0.05). There was no significant difference in the elimination half-life of atracurium between the two groups. The total volume of distribution of laudanosine was increased in cirrhotic patients (2.68 litre kg-1) (P less than 0.05), as was its elimination half-life (277 min in cirrhotic individuals; 168 min in controls) (P less than 0.05). There was no significant difference in the clearance of laudanosine between the two groups.

Atracurium↗
PubMed1989

Pharmacokinetics of atracurium and laudanosine in the elderly.

The pharmacokinetics of a bolus dose of atracurium 0.6 mg kg-1 and its metabolite laudanosine were studied in 11 elderly (mean age 80.9 yr) and 10 young patients (mean age 23.8 yr) undergoing elective surgery. The elimination half-life (T1/2 beta) of atracurium was significantly longer in the elderly group (23.1 v. 20.1 min), but there was no significant difference between the two groups in clearance (Cl), the volume of distribution (V beta) or the mean residence time (MRT) of atracurium. Laudanosine T1/2 beta was also significantly longer (229.1 v. 173.1 min) and the clearance significantly slower (4.85 v. 7.29 ml min-1 kg-1) in the elderly. There was, however, no significant difference in V beta for laudanosine between the two groups. These data suggest that atracurium depends to a small extent on the liver or the kidney for its metabolism and excretion, and that, as these routes of excretion are less efficient in the elderly, T1/2 beta is prolonged in this age group. The deteriorating function of these organs with increasing age may also explain the altered pharmacokinetics of laudanosine.

Adult↗
PubMed1989

Rehabilitation of the injured hand.

The gradual development of hand surgery as an area of specialization has led to the development of rehabilitative efforts that have complemented this trend. This had led to further specialization in hand therapy as a primary endeavor. Specific efforts in the areas of rehabilitation for soft tissue, bone, tendon, and nerve injuries have facilitated functional restoration of the injured hand.

Hand Injuries↗
PubMed1988

Active tendon implants in flexor tendon reconstruction.

Forty-five active flexor tendon implants were evaluated after placement in scarred tendon beds of digits II through V. The implant is constructed of silicone rubber with a Dacron core, terminating in a loop proximally and a metal plate distally. Modification of the implant during the period of study has improved its reliability and longevity. The improvement in total active motion (TAM) averaged 72 degrees during implant functioning (stage I) in a group of digits that before operation were classified as 78% Boyes grade 5 (salvage). Complication rate during stage I was 11% (5 out of 45). Of the 27 digits evaluated after implant replacement by tendon autograft (stage II), there was an overall improvement in 62 degrees total active motion with 70% of digits being Boyes grade 5. Many of the complications were believed to be avoidable with experience. This study demonstrates the feasibility of an active tendon implant and the possibility of a permanent prosthesis.

Adolescent↗
PubMed1988

Disposition of infusions of atracurium and its metabolite, laudanosine, in patients in renal and respiratory failure in an ITU.

A study of plasma atracurium and laudanosine concentrations was undertaken in 14 critically ill patients who received a bolus dose of atracurium 0.6 mg kg-1 followed by an infusion of 0.6 mg kg-1 h-1 for a period of 11-47 h. Seven of the patients had normal renal function and seven were in acute renal failure. In both groups plasma concentrations of atracurium reached a plateau of approximately 1300 ng ml-1 within 30 min of the bolus dose. The drug disappeared from the plasma within 120 min after discontinuation of the infusion. There was no difference between the two groups with respect to the pharmacokinetic parameters derived for atracurium. In the patients with normal renal function, plasma laudanosine concentration reached a plateau of approximately 1200 ng ml-1 within 10 h. In patients with renal failure there was a greater variation in the plasma laudanosine concentration: the highest value recorded was 4300 ng ml-1. Patients with renal failure had a significantly longer mean elimination half-life for laudanosine (1418 min v. 375 min; P less than 0.05) and Vd (4.52 litre kg-1 v. 2.40 litre kg-1; P less than 0.01) than the patients with normal renal function.

Acute Kidney Injury↗
PubMed1988

Antagonism of blockade produced by atracurium or vecuronium with low doses of neostigmine.

Neostigmine 1.25 mg or 0.625 mg was used to antagonize neuromuscular blockade produced by either atracurium 0.5 mg kg-1 or vecuronium 0.1 mg kg-1 in four groups of patients (n = 45) when the first EMG response of the train-of-four (A') had recovered to 10% of control (A). The time for A'/A and the train-of-four ratio (D'/A') to reach 70% was recorded. It was found that, after both atracurium and vecuronium, neostigmine 1.25 mg considerably accelerated recovery and, when compared with previous results, differed little from neostigmine 5.0 mg or 2.5 mg. Neostigmine 0.625 mg also significantly accelerated recovery after atracurium and was comparable to neostigmine 1.25 mg. However, with neostigmine 0.625 mg after vecuronium, recovery of D'/A' (but not A'/A) was little faster than spontaneous. Neostigmine 1.25 mg appears to be almost as effective as neostigmine 5.0 mg or 2.5 mg in antagonizing considerable block (90% depression of twitch height) produced by either atracurium or vecuronium, but neostigmine 0.625 mg is not sufficient, especially after vecuronium.

Adult↗
PubMed1988

The prolonged use of atracurium in a patient with tetanus.

A case of a patient with tetanus is reported in whom an atracurium infusion and artificial ventilation were needed in addition to sedation to control the muscle spasms. The atracurium infusion was used for 71 days, the longest time ever recorded, at a mean rate of 1.3 mg/kg/hour at the end of infusion. The plasma atracurium and laudanosine concentrations were 1.5 micrograms/ml and 0.985 micrograms/ml respectively. Subsequently there was an exponential decline in the serum laudanosine concentration which had decreased to 0.014 micrograms/ml 24 hours later. These results suggest that prolonged use of atracurium by infusion is not associated with excessive cumulation of laudanosine when renal and hepatic function are normal.

Adult↗
PubMed1987

Haemodynamic effects of the i.v. administration of cimetidine or ranitidine in the critically ill patient. A double-blind prospective study.

The cardiovascular effects of i.v. cimetidine 200 mg or ranitidine 50 mg were investigated in a double-blind cross-over study of 20 critically ill patients in an intensive therapy unit. Both agents caused transient decreases in mean arterial pressure and systemic vascular resistance, although there was no significant change in heart rate, cardiac output, central venous pressure, pulmonary artery wedge pressure or pulmonary vascular resistance in either group. The hypotensive, systemic vasodilatory effect was more common after cimetidine than after ranitidine. Also, it was significantly greater after cimetidine. Both histamine H2-receptor antagonists may cause hypotension in the critically ill patient.

Adult↗