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Biomedical subjects

S H Miller

Publications and source records attributed to S H Miller.

At least 91 records · Page 5Linked to original sources

Intravascular coagulation and fibrinolysis within primate extremities during tourniquet ischemia.

A common although infrequently recognized complication associated with the use of a pneumatic tourniquet is profuse bleeding from the wound after deflation of the tourniquet. The purpose of this study was to determine whether intravascular coagulation and fibrinolysis could be induced in subhuman primates by tourniquet ischemia, and whether this phenomenon could be altered by pretreatment of the animal with heparin. It was shown that, after 2(1/2) hours of tourniquet ischemia, (400 mmHg) to one lower limb, fibrinogen levels were significantly lower (p < .005), antithrombin III levels were significantly lower (p < .05), plasminogen levels were significantly lower (p < .05), fibrin split products significantly higher (p < .025) and fibrinopeptide A levels were significantly higher (p < .02) than values measured simultaneously in the control limbs. After pre-treatment with sodium heparin, 30 units/kg, there was no change in antithrombin III levels or fibrinogen levels, but fibrin split products in the experimental limbs were significantly elevated (p < .05) when compared to control limbs. In both groups the abnormal levels returned to control levels 5-30 minutes after tourniquet deflation. We conclude that intravascular coagulation and fibrinolysis develop within ischemic subhuman primate limbs during tourniquet ischemia. Pretreatment with heparin prevents the consumption of fibrinogen and antithrombin III but does not prevent the increase in fibrin split products which was observed. It is possible that intravascular coagulation and fibrinolysis contribute to post tourniquet bleeding.

Animals↗

The effects of reserpine on microcirculatory flow in rat flaps.

A model flap was developed in the rat which allowed us to quantitate microcirculatory blood flow within a flap, and to correlate the flow with the length of flap eventually surviving. A critical flow of 0.02 and 0.03 ml/min/gm (measured during the first 24 hours after flap elevation by radioactive microspheres) appears to be necessary for tissue survival. Reserpine, in a dose of 5 mg/kg, did not increase blood flow in the flap or the length of flap surviving in this model.

Animals↗

Long-term survival with thorotrast cervical granuloma.

Thorium dioxide, a radioactive contrast material, was commonly used for cerebral angiography prior to recognition of its radiation hazard. Extravasation of the material into the extravascular tissue in the neck results in granuloma formation, thorotrastoma, long-term morbidity, and an increased incidence of benign and malignant tumors. We report our experience with the management of 2 patients who underwent cerebral angiography with thorotrast more than 25 years ago. Aggressive surgical excision of involved tissue is warranted to ameliorate symptoms and diminish the risk of malignancy.

Adult↗

The acute effects of tourniquet ischemia on tissue and blood gas tensions in the primate limb.

Tourniquet ischemia results in tissue hypoxia which has been measured indirectly by blood gas analysis. The Medspect mass spectrometer allows direct measurement of gas tension in different tissues and may provide more useful information regarding safe tourniquet times. Calibrated Teflon catheters were inserted into the subcutaneous tissue (11 animals), tibial medullary cavities (bone) (nine animals), and tibialis anterior muscles (10 animals) in both lower extremities of anesthetized stumptail monkeys. Tourniquet ischemia was maintained for 1 hour at 400 mm Hg. Tissue and venous blood gas tensions were recorded from both limbs for 1 1/2 hours. Comparisons between gas tensions in each tissue group were made on the basis of their percentage change from control values. In the ischemic limb within 5 minutes muscle PO2 fell 42 +/- 4% (p is less than 0.001), whereas bone and subcutaneous PO2 dropped 25 +/- 4% (p is less than 0.05). Blood PO2 fell 29 +/- 3% and differed only from that of muscle (p is less than 0.01). One hour after tourniquet inflation, blood PO2 levels has fallen 90 +/- 5% (p is less than 0.001) from their control. Changes in tissue PCO2 were less dramatic and did not vary significantly from those recorded in venous blood. After deflation, blood PO2 exceeded its control by 20 +/- 6% (p is less than 0.005) in 5 minutes, but tissue tensions remained 50 +/- 6% below their control values. These studies indicate that tissue gas tensions are a more sensitive indicator of tourniquet hypoxia than are blood gases within the ischemic extremity.

Animals↗

Power take-off injuries.

Power take-off injuries are uncommon, but serious and potentially fatal. Seven cases are reported demonstrating the violent trauma that can be incurred. The danger associated with use of machines with this and other power equipment is emphasized. Safety shields should be improved, and operators educated about the importance of retaining the shields and using machinery properly at all times.

Accidents, Occupational↗

Management of fractures of the supraorbital rim.

The frequency of supraorbital rim fractures is increasing as incidence of motorcycle and bicycle accidents increases. These fractures are frequently depressed, comminuted, and often extend into the frontal sinus. Open reduction and fixation are the treatment of choice. Adequate debridement and cleansing with preservation of periosteum and blood supply are recommended. Unstable fragments can be fixed to the frontal bone or stabilized by suturing the torn periosteum. Severely comminuted supraorbital frontal sinus fractures may require stabilization via frontal sinus pack or balloon. We feel the latter is preferable and both Foley and Fogarty catheters have been successfully used.

Adolescent↗

Bacteriology of chronic leg ulcers.

The quantitative bacteriology of 13 chronic leg ulcers was sequentially assessed by both swab and biopsy culture techniques, and the effect of either a 10% benzoyl peroxide lotion or placebo lotion was evaluated. There was good correlation between the swab and biopsy culture techniques in 12 of the 17 instances where simultaneous swabs and biopsies were done. Though the benzoyl peroxide did not favorably affect the bacterial flora, ulcer healing did appear to correlate with quantitative bacterial counts. THREE of five ulcers containing fewer than 10(5) organisms per gram of tissue or per centimeter of ulcer surface area healed, while none of eight ulcers containing more than 10(5) organisms healed. Quantitative bacteriological measurements can serve as useful tools in evaluating healing of leg ulcers.

Adult↗

The team approach to treatment of the cleft lip and palate.

The team consists of a family physician, plastic surgeon, orthodontist, prosthodontist, otolaryngologist, speech therapist, audiologist and social worker. A cleft lip is usually repaired when the child weighs 10 lb., is 10 weeks old and has 10 Gm. of hemoglobin. Defects of the secondary palate are repaired between one and two years of age; residual lip or nasal deformities are corrected before the child starts school. Further cosmetic surgery is delayed until adolescence, when facial growth has been completed.

Child↗

Gas chromatographic determination of cocaine in whole blood and plasma using a nitrogen-sensitive flame ionization detector.

A procedure is described for the determination of as little as 20 ng of cocaine from 1 ml of whole blood or plasma. Methods are also given for the storage of whole blood or plasma containing cocaine as well as for whole blood or plasma extracts. Blood levels in patients receiving intranasal cocaine for topical anesthesia while undergoing rhinoplasty are also presented.

Chromatography, Gas↗

Acessory nerve function after surgical procedures in the posterior triangle.

Seventeen patients who had undergone surgical procedures in the posterior triangle of the neck were examined between one day and four years after operation. Eleven patients were studied with electromyography. Clinical and electromyographic evidence of 11th cranial nerve paresis was present in 12 patients. Partial nerve injuries and entrapments, as suggested by delayed symptoms and incomplete denervation on electromyographic studies, were frequent. Physiotherapy was effective in restoring a satisfactory, although in many cases an incomplete, return of function. The spinal accessory nerve appears to be vulnerable to injury despite careful preservation during surgical dissection.

Accessory Nerve↗