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Biomedical subjects

R K Spence

Publications and source records attributed to R K Spence.

At least 73 records · Page 4Linked to original sources

Traumatic disruptions of the thoracic aorta: treatment and outcome.

Of 27 patients admitted to our level I trauma center with acute disruption of the thoracic aorta, two patients died of exsanguination before aortic repair. One patient had massive leakage from the aneurysm after aortography and died during surgery. All patients suffered from multiple injuries. Eighty-three percent of the patients had major operations in addition to the aortic repair. "Clamp and sew" technique was used in 18 patients (75%), two of whom had multiple tears of the aortic arch. Heparin-coated shunts were used in five patients (20.8%), and a cardiopulmonary bypass was performed in one patient who had multiple tears. Three postoperative deaths were related to polytrauma, cardiogenic shock, and sepsis. Paraplegia developed in three patients, two of whom had multiple aortic lesions necessitating longer ischemia time during the repair. Only one patient had complete neurologic deficit at the 1-year follow-up. In our series, neither surgical procedure proved superior. We conclude that the "clamp and sew" technique for repair of the disrupted thoracic aorta may allow for a more favorable outcome.

Adult↗

Preventive effect of Fluosol-DA for paraplegia encountered after surgical treatment of the thoracic aorta. Preliminary results in a dog model.

The effectiveness of Fluosol-DA (Green Cross Corporation, Osaka, Japan) on circulatory dynamics and neurologic outcome in dogs with ischemic spinal cord injury produced by aortic crossclamping was tested. The control group (receiving saline solution) had an elevated mean aortic proximal pressure (112.9 +/- 30.2 mm Hg versus 175.3 +/- 20.5 mm Hg, p greater than 0.05) and a drastic drop in mean distal aortic pressure (112.9 +/- 30.2 mm Hg versus 29.8 +/- 11.2 mm Hg, p less than 0.05). Although the same trend occurred in dogs treated prophylactically with Fluosol-DA, these changes were not statistically significant. However, there was a significant difference in mean distal aortic pressure during the ischemic phase between the two groups (58.9 +/- 16.0 mm Hg versus 29.8 +/- 11.2 mm Hg, p less than 0.05). Postoperatively all animals had mean arterial pressures within the normal range. All dogs in the control group were paraplegic (partial or complete); the treatment group had one dog with partial paraplegia. The difference between the mean neurologic scores of the two groups was of high statistical significance (3.7 +/- 0.5 versus 1.6 +/- 1.0, p less than 0.05). Our preliminary results show that prophylactic use of Fluosol-DA has favorable effects on hemodynamics and neurologic outcome in dogs with spinal cord ischemia produced by aortic crossclamping. The high propensity of the drug to carry oxygen and carbon dioxide and to provide nutritional support to the ischemic area with resultant improvement in local microcirculation and blood rheology are some speculative mechanisms advocated for these changes.

Animals↗

Right ventricular myocardial protection through intracavitary cooling in cardiac operations.

In an attempt to protect the right ventricle, we designed and tested a closed cooling system that circulates cold saline through a double-lumen, balloon-tipped catheter positioned in the right ventricular cavity. Fourteen sheep were randomly assigned to two groups. In group A (n = 7), the right ventricular cooling catheter system was used in addition to coronary cardioplegic perfusion and systemic hypothermia for myocardial protection. Group B (n = 7) served as a control group. In group A, the right ventricular temperatures were significantly lower than those of the control group (16.1 degrees +/- 0.3 degrees C versus 23.9 degrees +/- 0.4 degrees C; p less than 0.0001, Student's t test). The most common temperature range was 12 degrees to 18 degrees C (67.1%, frequency distribution analysis), and 63.2% of temperatures were below 16 degrees C. The catheter system also maintained the temperatures of the interventricular septum at a lower level than those recorded in the control group and prevented septal rewarming, which was significant in group B (from 16.5 degrees +/- 1.5 degrees C to 25.0 degrees +/- 0.9 degrees C; p less than 0.04, Mann-Whitney U test). Left ventricular temperatures were not changed by the catheter system. By better cooling the right ventricle and the septum, the right ventricular cooling catheter system should decrease the prevalence of right ventricular failure and allow more time to safely complete multiple coronary anastomoses in coronary artery bypass graft operations.

Animals↗

Severity of anaemia and operative mortality and morbidity.

In a case-control study of 125 surgical patients who declined blood transfusions for religious reasons operative mortality was inversely related to the preoperative haemoglobin level, rising from 7.1% for patients with levels above 10 g/dl to 61.5% for those with levels below 6 g/dl. Mortality rates were also related to blood loss during surgery, rising from 8% for patients who lost less than 500 ml to 42.9% for those who lost more than 2000 ml. Both preoperative haemoglobin level and operative blood loss should be considered in assessing the need for preoperative transfusion. In our study no patient with a haemoglobin level above 8 g/dl and operative blood loss below 500 ml died.

Analysis of Variance↗

Hemorrhoidectomy in the patient with multiple or circumferential hemorrhoids.

A technique is presented that allows complete removal of hemorrhoids even when large hemorrhoids exist between the classic three major hemorrhoidal locations. Since the anorectal mucosa overlying these "interval" hemorrhoids is preserved, there is no increased tendency for stricture formation to occur.

Hemorrhoids↗

Coexistant gastric duplication and accessory pancreas: clinical manifestations, embryogenesis, and treatment.

Combined gastric and pancreatic duplications are uncommon. Although patients usually present with symptoms of intestinal obstruction, gastrointestinal (GI) bleeding may occur if the duplication ulcerates and erodes into a neighboring hollow viscus. An upper GI series and barium enema are helpful in making a diagnosis. Combined duplications probably are produced during embryologic development by traction along a neuroenteric band between the stomach and pancreas. Simple surgical excision is the treatment of choice.

Female↗

Economic impact of transluminal angioplasty.

Using actual bills and follow-up records we attempted to determine the economic impact of percutaneous transluminal angioplasty. The patients selected included forty angioplasties performed early in our experience as well as forty comparable patients who had operations in the same period of time. Clinical follow-up was obtained over four years. The statistics obtained demonstrate the hospital bills for angioplasty were only 24% that of surgical treatment for femoral lesions ($1,329.00 versus $6,112.00) and 16% for iliac lesions ($1,353.00 versus $7,732.00). Using this patient sample and readily available statistical data, we calculated direct national savings for using angioplasty on all patients suitable and used a standard value of life analysis to estimate the value of lives saved by doing the less dangerous procedure. The sum total savings in the United States from using angioplasty in all suitable candidates as opposed to surgery would be $180 million per year for femoral lesions and $117 million for iliac lesions. This could produce a significant savings in medical costs over the coming years.

Actuarial Analysis↗

Fluosol-DA, a perfluorochemical oxygen-transport fluid for the management of a trochanteric pressure sore in a Jehovah's Witness.

A 54-year-old paraplegic with a right trochanteric pressure sore was refused reconstructive surgery because of his hemoglobin count of 6 gm/dl and his refusal to accept blood transfusions because of religious beliefs. Utilization of Fluosol-DA, a perfluorochemical oxygen-transport fluid that has recently become available to us for clinical trial, enabled us to deal successfully with this man's problem despite the profound anemia, since tissue oxygen delivery was provided with arterial oxygen partial pressures as high as 500 torr after infusion. Patients previously denied operations on the basis of their blood counts and their refusal to receive blood transfusions may in the future be offered the option of an oxygen-carrying fluid such as Fluosol to allow them to safely undergo reconstructive procedures.

Christianity↗

Mycobacterial infections in renal allograft recipients.

Primary mycobacterial infections developed in five of 565 patients who had transplants during a 15-year period. All had negative PPDs and normal chest roentgenograms; none had tuberculosis before transplantation. Atypical mycobacteria were cultured in three of five infections. All were treated with a multiple-drug regimen, including isoniazid, rifampin, ethambutol, and streptomycin sulfate. In four of five patients, there were serious drug-related complications. No major initial alteration of immunosuppressive therapy was necessary in any of the patients. During the study, a treatment policy was followed that included one year of isoniazid treatment of all recipients with a positive PPD, history of tuberculosis, chest x-ray film suggestive of tuberculosis, or PPD-positive donor. An additional 14 transplant recipients were treated in accordance with this policy without complications or subsequent mycobacterial infections (32-month average follow-up). Despite the low incidence of mycobacterial infection in this series, the potential lethality and morbidity mandate constant vigilance.

Adult↗

Lethal post-transplantation calcinosis.

The case studies of four patients with post-transplantation calcinosis are presented. Three of the four patients died of inanition and sepsis secondary to infection of extensive soft tissue ulcers and diffuse cutaneous vascular calcification with gangrene. The fourth patient survived following removal of all four parathyroid glands and autografting of approximately one-half of one gland. Common to the patients was secondary hyperparathyroidism, elevated mean serum calcium levels after transplantation, and radiographic evidence of small and medium vessel calcification. No other differences could be found between these patients and other patients with post-transplantation hyperparathyroidism without calcinosis. In the face of apparently minor complaints of lower extremity discomfort, elevated parathyroid hormone levels (PTH) and positive xerography may indicate subtotal parathyroidectomy regardless of the serum calcium level.

Adult↗

Minocycline-induced black thyroid gland: Medical curiosity or a marker for papillary cancer?

PURPOSE: Black pigmentation of the thyroid gland is a rare side effect of minocycline. METHODS: Only 26 cases, in addition to the 2 we present, have been reported in the literature. Eleven cases of thyroid carcinoma associated with black thyroid syndrome have been reported. CONCLUSIONS: The incidence of papillary cancer may be increased in thyroid glands stained by the minocycline pigment, which warrants an increased index of suspicion in patients who develop thyroid nodules and have previously been treated with minocycline.

Journal Article↗