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Biomedical subjects

R W Feldtman

Publications and source records attributed to R W Feldtman.

18 recordsLinked to original sources

Linear response of collateral cerebral perfusion pressure during carotid clamping.

Phenylephrine is frequently used to increase systemic arterial pressure during carotid endarterectomy. However, little is known of its effect on collateral cerebral perfusion pressure, particularly in patients with high collateral cerebral vascular resistance who are at increased risk of cerebral ischemia during carotid clamping. We tested the hypothesis that this subset of patients can have collateral perfusion pressure, and hence collateral cerebral blood flow, increased in a predictable way by elevating systemic arterial pressure. We measured mean systemic arterial pressure (Pa), jugular venous pressure (Pv), and mean carotid back pressure (Pc), and calculated collateral cerebral perfusion pressure (P = Pc - Pv) and the ratio of collateral to ipsilateral hemisphere cerebral vascular resistance (Rc/Rh) in 18 patients with low P. Initial measurements were Pa = 84 +/- 8.8 (mm Hg, mean +/- SD), Pv = 7.8 +/- 3.9, Pc = 26 +/- 5.1, P = 18 +/- 4.5 and Rc/Rh = 3.4 +/- 1.15. During phenylephrine infusion, Pa = 108 +/- 11, Pc = 32 +/- 6.5, and P = 24 +/- 7.2, increases of 29, 23, and 33%, respectively (P less than 0.05). Unchanged were Pv = 8.2 +/- 4.1 (5%) and Rc/Rh = 3.5 +/- 1.30 (3%) (P greater than 0.8). The latter two findings indicate that cerebral perfusion pressure and mean systemic arterial pressure are linearly related according to the fluid mechanics equation governing these parameters: Pa = P(Rc/Rh + 1) + Pv. These results support the use of phenylephrine to increase collateral blood flow during carotid endarterectomy in patients with low cerebral perfusion pressure.

Blood Pressure

Safe, cost-effective postoperative nutrition. Defined formula diet via needle-catheter jejunostomy.

To assess the safety and cost-effectiveness of needle-catheter jejunostomy for the purpose of feeding defined formula diet, we studied 199 consecutive patients who underwent major elective and emergency abdominal operations between July 1975 and June 1978 and in whom a needle-catheter jejunostomy was inserted. The complication rate was 2.5 per cent (1 per cent major and 1.5 per cent minor) during 7,238 patient-days of catheter exposure during which over 6 million calories were administered. There were no catheter-related deaths, bowel obstructions, bowel perforations, or intraperitoneal administration of feeding formula. The presence of a route of intestinal access and the use of defined formula diet in 111 patients who were unable to eat for over 10 days postoperatively resulted in a gross cost savings of almost $50,000 and a net savings of almost $33,000 by avoiding the necessity for central total parenteral nutrition. We belive the technique of needle-catheter jejunostomy is both safe and cost-effective in the administration of defined formula diet in the postoperative period, and we suggest that other surgeons gain experience with the technique to define its role in their own therapeutic armamentarium.

Adolescent

Meeting exceptional nutritional needs. 1. Total parenteral nutrition.

The provision of adequate nutrition to hospitalized patients with exceptional caloric requirements has been a problem until the recent advent of intravenous hyperalimentation. With total parenteral nutrition (TPN), the nutritional needs of any patient can be met by infusion. TPN solution is hypertonic, and administration requires central venous cannulation. The subclavian vein is usually chosen as route of access to the superior vena cava. Strict aseptic technique must be used in inserting the catheter and making up and administering the solution. TPN is not without risk. Infection is always a possibility, as are metabolic alterations, such as electrolyte imbalance, fluid overload, osmotic dehydration, and essential fatty acid deficiency.

Catheterization

Meeting exceptional nutritional needs. 2. Elemental enteral alimentation.

Elemental enteral alimentation (EEA) is an alternative to parenteral nutrition in patients with a functioning gastrointestinal tract and increased caloric requirements or in whom regular oral feeding is impossible or impractical. EEA is given by nasogastric, jejunostomy, or gastrostomy tube. It is useful in cases of short-gut syndrome, pancreatic disease, partial intestinal obstruction, colitis, neuropsychiatric cachexia, trauma, fistula, vascular insult, and renal and liver disease, as well as in patients being prepared for surgery or requiring hyperalimentation after surgery or abdominal irradiation. Strict attention must be paid to fluid and electrolyte status and to blood and urine glucose levels in patients receiving EEA. With use of a nasogastric tube, infection of the middle ear is a possible but uncommon complication.

Cachexia

Bronchial carcinoid tumors in children and adolescents.

Thirteen histologically proven cases of bronchial carcinoid from the literature and eight cases from the Armed Forces Tumor Registry, all under 20 yr of age, are presented. Hemoptysis, cough, and pneumonia were the most frequent presenting complaints. Bronchoscopy defined the lesion in all 16 cases so studied. Gross and microscopic pathology is briefly described, and treatment in these cases outlined. A good long-term prognosis can be expected, except in those cases with a long delay in diagnosis.

Adolescent

Practical role for ultrasound in diagnosis of deep venous thrombosis of lower extremities.

The Doppler Ultrasonic Velocity Detector has been shown to be of significant value in the evaluation of patients with suspected deep venous thrombosis. Our experience in 121 patients demonstrates a false-negative rate of 10% for "minimal" thrombophlebitis and 3.2% for ileofemoral thrombosis when the Doppler was used as a diagnostic aid. Since ileofemoral thrombosis represents the greatest threat to the patient in terms of pulmonary embolism, this appears to be a sensitive and specific technic for the detection of ileofemoral thrombosis.

Acute Disease

Continual catheter administration of an elemental diet in infants and children.

Elemental diet offers a safe, simple, widely applicable technique for providing nutritional support in infants and children, thus protecting them against the hazards of malnutrition. Continual catheter administration of elemental diet provides an avenue of nutritional support free of many of the complications associated with total parenteral nutrition. Although mechanical and metabolic complications were avoided by rigid protocol compliance in our group of over 150 patients, further metabolic studies may suggest minor compositional changes providing a more optimal diet for premature and newborn infants.

Abnormalities, Multiple

Hospital electrical safety.

Electrocution is an environmental hazard for hospital personnel and patients. The source is low-level alternating current, accidentally applied through indwelling electrodes which invade the normally protective high resistance of the body. Probably the greatest offender is the combination of electronic monitoring and the electrically operated bed. Preventive measures include education of medical personnel and the establishment of guidelines on leakage, coupled with periodic maintenance and inspection by trained technicians.

Electric Injuries

Human skin burns induced by defibrillator default current.

The attachment of various types of electronic instrumentation to a patient can lead to hazardous interactions. Component malfunction in a single piece of equipment connected to a patient may be totally innocuous. However, the same fault occurring in an identical piece of equipment functioning as one component in a network of monitoring and electrosurgical equipment can result in severe burns or even electrocution. This paper describes interaction between a defective defibrillator paddle and an electrosurgical unit. Burns and ventricular fibrillation resulting from this malfunction and interaction are described in detail and the electrical circuits are analyzed.

Burns, Electric

Pyloric stenosis: a 13-year experience in operative management.

Infantile hypertrophic pyloric stenosis is best treated surgically, after an appropriate period of rehydration and resuscitation. Our experience with this entity has resulted in the performance of fewer contrast studies to establish the diagnosis as well as the use of an operative technique which can be safely applied to the teaching environment.

Follow-Up Studies

Doppler ultrasonic flow detection as an adjunct in the diagnosis of patent ductus arteriosus in premature infants.

Since ligation of a patent ductus arteriosus in the neonate with idiopathic respiratory distress syndrome seems to improve the clinical condition of the infant, we have attempted to identify those neonates earlier with the noninvasive Doppler ultrasonic technique, recording brachial arterial flow signals. Sixteen patients were studied. In the 5 with reversed brachial flow who were operated upon, ligation of a PDA resulted in improvement and postoperative correction of brachial flow reversal as evidenced by the Doppler ultrasonic technique.

Doppler Effect

Dissimilar metals in a rib spreader a surgical electrical hazard.

A case is presented and electrochemical theory is discussed in a situation in which a battery was produced between two dissimilar metals in a Finochietto rib spreader. The problem developed in the thorax of a patient undergoing transthoracic cervical sympathectomy and resection of the first rib. Caution is advised in the use of dissimilar metals in patients undergoing surgery.

Adult