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Biomedical subjects

J T Harvey

Publications and source records attributed to J T Harvey.

33 records · Page 2Linked to original sources
PubMed1990

Plasma catecholamine concentration during sedation in ventilated patients requiring intensive therapy.

The effects of isoflurane and midazolam sedation on the catecholamine responses of ventilated patients were studied over a 24-h period. Sixty ventilated patients admitted to our intensive therapy unit were allocated randomly to receive either isoflurane or midazolam sedation. Arterial blood samples for plasma catecholamine concentrations were taken at baseline, 6 h after starting sedation and at the end of the study period. Patients sedated with isoflurane showed a progressive reduction in both adrenaline and noradrenaline concentrations during the period of sedation which reached statistical significance for adrenaline at 6 h (p less than 0.02) and at the end of the study (p less than 0.001). Patients sedated with midazolam showed no significant changes of adrenaline or noradrenaline concentrations. Overall, a more satisfactory degree of sedation was achieved with isoflurane.

Administration, Inhalation↗
PubMed1989

Computer controlled infusion of propofol.

A computer controlled infusion pump was used to deliver propofol to two groups of eight patients undergoing body surface surgery. The patients were premedicated with morphine sulphate i.m. and anaesthesia was supplemented with 66% nitrous oxide in oxygen. Patients in group 1 breathed spontaneously, whereas patients in group 2 underwent artificial ventilation to a normal PaCO2. The computer program was designed to achieve and maintain a blood concentration of propofol 3 micrograms ml-1 as rapidly as possible, basing calculations on a three-compartment pharmacokinetic model. Mean blood propofol concentrations were found to be close to the predicted target from 10 to 120 min in group 1, but were 5-20% higher from 20 min in group 2.

Adult↗
PubMed1989

Orbital decompression for Grave's disease leaving the periosteum intact.

A prospective trial was carried out to determine whether or not transorbital floor and medial wall decompression without opening the orbital periosteum would relieve compressive optic neuropathy in patients with Grave's disease. In four orbits (three patients), the procedure was performed, and in all cases, the vision returned to 20/30 or better. All other parameters of optic nerve function improved as well. No patient had worsening of ocular motility that was attributable to the surgery. The amount of retroplacement of the globe may be less than with standard orbital decompression.

Adult↗
PubMed1988

Ranking clinical problems and ocular diseases in ophthalmology: an innovative approach to curriculum design.

The MD program of the Faculty of Health Sciences, McMaster University, Hamilton, Ont., has used a problem-based, self-directed, small-group learning approach to medical education since 1969. Substantial curriculum revision was begun in 1983 as part of a process of institutional renewal. A faculty survey of all academic clinicians in the Division of Ophthalmology, Department of Surgery, was carried out in 1984 to determine which problems and diseases the teaching faculty thought had the highest priority for student learning. The results have been used by educational planners in revising the curriculum. They have also served to clarify faculty members' expectations of students within an ophthalmology rotation.

Curriculum↗
PubMed1986

Occult transorbital intracranial penetrating injuries.

Emergency physicians who are confronted with orbital injuries must recognize that the transorbital route offers little resistance to intracranial penetration. Neither direct inspection of an orbital wound nor plain radiographs are sufficient to evaluate the extent of penetration beyond the orbital confines. A high index of suspicion is critical to the proper assessment and subsequent management of such injuries. We present two cases of penetrating injury. In the first, an arrow caused a hematoma in the superior cerebellar peduncle after passing through the medial orbit and superior orbital fissure. In the second, a wire entered the upper lid, fractured the orbital roof, and caused a frontal hematoma.

Adolescent↗
PubMed1986

Studies of anaesthesia in relation to hypertension. VII: Adrenergic responses to laryngoscopy.

Arterial pressure and plasma catecholamine concentrations were measured in 16 normotensive and 10 hypertensive patients undergoing elective vascular surgery. Following induction of anaesthesia, both arterial pressure and plasma noradrenaline concentrations decreased in both groups. Following laryngoscopy, there was a moderate increase in arterial pressure in both normotensive and hypertensive patients. In normotensive patients, laryngoscopy was associated with a moderate increase in plasma noradrenaline concentration. There was no change in adrenaline concentration. By contrast, there was a marked increase in noradrenaline concentration, a moderate increase in adrenaline concentration and an arterial pressure response in the group of hypertensive patients. These data are consistent with transient sympathetic overactivity in hypertensive patients following noxious stimuli such as laryngoscopy.

Adrenergic beta-Antagonists↗
PubMed1986

Sheep botfly: ophthalmomyiasis externa.

Sheep botfly (Oestrus ovis) conjunctival infestation is rare in North America but is common in other parts of the world. The author treated 30 patients with this type of conjunctivitis in Jerusalem in 1981 and 1982. The conjunctivitis may vary from mild to severe (pseudo-orbital cellulitis). Features of the conjunctivitis include pale edema, linear superficial punctate keratopathy and the presence of larvae in the conjunctival sac. Conjunctival scrapings revealed a preponderance of polymorphonucleocytes.

Animals↗
PubMed1985

Voluntary entropion.

Voluntary entropion, which has been reported only once before, was photographically documented in a 12-year-old girl. The lower-eyelid retractors and protractors were clinically normal. The postulated mechanism of the entropion was selective innervational control of separate components of the orbicularis oculi complex, which allowed the preseptal portion to override the pretarsal portion.

Child↗
PubMed1984

Plasma concentrations of catecholamines following adrenaline infiltration during gynaecological surgery.

High pressure liquid chromatography with electrochemical detection has been used to measure plasma catecholamine concentrations in six gynaecological patients undergoing halothane anaesthesia for cervical cone biopsy. Mean catecholamine concentrations before infiltration were 1.01 +/- 0.23 (SEM) nmol litre-1 (185 +/- 43 pg ml-1) for adrenaline, and 2.2 +/- 0.25 nmol litre-1 (364 +/- 41 (185 +/- 43 pg ml-1) for adrenaline, and 2.2 +/- 0.25 nmol litre-1 (364 +/- 41 pg ml-1) for noradrenaline. Following infiltration with 0.5% bupivacaine 15 ml with adrenaline 1:200 000, plasma adrenaline concentrations increased to a mean peak concentration of 18.6 +/- 3.7 nmol litre-1 (3.4 +/- 0.69 ng litre-1). The lack of sympathoneuronal response was confirmed by simultaneous measurements of plasma noradrenaline concentrations, which did not change significantly. The proportion of the injected adrenaline measured in the intravascular compartment was 21.8%. The significance of intravascular absorption of exogenous adrenaline is discussed in relation to the use of halothane anaesthesia and the concurrent injection of a local anaesthetic solution.

Absorption↗
PubMed1982

The management of meibomian gland carcinoma.

We present nine cases of sebaceous adenocarcinoma seen on the Oculoplastic Service at the University of Iowa over the past five years. It is essential to make the biopsy-proven diagnosis of meibomian gland adenocarcinoma promptly, using multiple full thickness eyelid biopsies. We recommend the Mohs' fresh-frozen technique in patients with surgically resectable lesions, exenteration in those with orbital extension, and radical neck dissection for cases with nodal involvement. Radiotherapy may be indicated in patients with extensive tumors who cannot tolerate or refuse surgery or as an adjunct to surgery in others.

Adenocarcinoma↗
PubMed1981

Lid splitting and posterior lamella cryosurgery for congenital and acquired distichiasis.

Congenital distichiasis is a rare condition with an accessory row of lashes at the Meibomian gland orifices. We suggest "acquired distichiasis" as an appropriate term for the accessory row of lashes in or near the Meibomian gland orifices, occurring as a result of such conditions as Stevens-Johnson syndrome, ocular pemphigoid, or chemical and physical injuries. We report a new treatment technique in which the eyelid is divided along the gray line then followed by cryotherapy to the posterior lid lamella. This removes the distichiatic lashes without damaging the normal lashes in the anterior lid lamella and avoids depigmentation. Histologic examination demonstrates the aberrant lashes result from a metaplasia of tissues in or around the Meibomian glands. Thirteen eyelids with acquired distichiasis and four eyelids with congenital distichiasis have been followed up for eight to 48 months. All have been greatly improved.

Adolescent↗
PubMed1981

The aponeurotic approach to eyelid retraction.

A technique for the upper lid retraction that involves an anterior approach similar to aponeurotic ptosis surgery is presented. Instead of advancing the aponeurosis, it is recessed and Müller's muscle is completely extirpated. The lateral horn of the levator must be cut to relieve the marked temporal elevation of the eyelid. Lid height and contour are adjusted intraoperatively with patient cooperation. In the lower lid, the retractors are recessed via a conjunctival approach unless simultaneously performed with orbital decompression. Any amount of lid retraction may be corrected by this technique in the upper lid and up to 3 mm of lower lid retraction can be corrected. Lid height in both the upper and lower lid is lasting and predictable. Thirty-one patients (63 eyelids) have been operated on using this technique with good results. Results in 17 patients (35 eyelids) with follow-up ranging from 8 to 42 months are presented.

Adult↗
PubMed1981

Lid lag and lagophthalmos: a clarification of terminology.

Lid lag, lagophthalmos and von Grafe's sign are useful terms which refer to important clinical signs. Despite the fact that they have discrete meanings, they are often used interchangeably and incorrectly by many ophthalmologists and, therefore, their value has been degraded. We provide definitions for these commonly used (but often confused) ophthalmic terms: Lagophthalmos is the inability to completely close the eyes; Lid lag is the static situation in which the eyelid is higher than normal with the globe in downgaze; and von Grafe's sign is a dynamic sign describing the retarded descent of the eyelid during movement of the globe from primary position to downgaze. It is our hope that these terms will be adopted by the ophthalmic community so that precision in definition will lead to clarity of thought and communication.

Blepharoptosis↗