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Biomedical subjects

J D Cohn

Publications and source records attributed to J D Cohn.

At least 19 recordsLinked to original sources
PubMed1986

Improved subclavian cannulation technique.

An improved subclavian cannulation technique using a 3 milliliter syringe attached to a No. 16 gauge needle and a guide wire is presented. Major complications, such as air embolism, vein laceration and retained catheter fragments, are eliminated by using this method of catheterization.

Catheterization↗
PubMed1985

Spontaneous major intra-abdominal arteriovenous fistulas: a report of several cases.

Most major intra-abdominal fistulas result from trauma or surgery. Spontaneous fistulas are rare with less than 100 reported cases since 1831. From a review of hospital records, five such spontaneous fistulas were identified among 215 cases of abdominal aortic aneurysm between 1975 and 1983. These cases are presented and supplemented by 73 similar cases collected from a literature review for discussion of the salient features of clinical presentation and management of spontaneous major fistulas. Major intra-abdominal arteriovenous fistulas usually present with a machinery bruit over a pulsatile mass, but may present more subtly with pain and otherwise unexplained hematuria. Because these fistulas lead to refractory heart failure, surgery should be expeditious. Closure should be performed from within the aneurysm with arterial and pulmonary artery pressure monitoring. Care must be taken to prevent pulmonary embolization.

Aged↗
PubMed1980

Monitoring operative risk in the elderly.

To reduce operative mortality in elderly patients, a system of preoperative staging, based on invasive monitoring, was developed. All of the 148 consecutive patients studied had been cleared for surgery by standard assessment, but only 13.5% had normal measured, hemodynamic, respiratory, and oxygen transport function. Mild physiologic aberrations, not requiring a delay in surgery, or more severe abnormalities, indicative of high operative risk, were found in 63.5% of the patients. Advanced and incorrigible functional defects found in the remaining 23% made them unacceptable risks for major surgery under general anesthesia, and all who underwent the planned operation in spite of the warning died. Invasive preoperative assessment of elderly patients discloses a high percentage of serious physiologic abnormalities requiring a delay in some and cancellation of the operation in others.

Aged↗
PubMed1979

Delayed pacemaker erosion due to electrode seal defects.

Over a 7-year period, follow-up data were available on 163 patients who underwent 209 pacemaker-related operations for initial insertion or revision of previously implanted units. During the follow-up period, 16 pacemaker generator units were remoaved from 16 pacemaker generator units were removed from 12 patients solely because of the development of local skin erosion. This represents a 7.7% incidence of pacemaker generator erosion. Tree units were removed within a 3-month interval following pacemaker implantation and were associated with positive bacterial cultures, theraby indicating an infectious cause. Findings at removal of the remaining 13 pacemaker generators included extensive fibrosis with chronic inflammation, fibroblastic proliferation, and granulation tissue, which was most prominent at the site of insertion of the pacemaker lead into the pacemaker generator unit. Granulation tissue frequently led from this area to the area of skin attenuation and erythema. Inspection of the pacemaker generator units and electrodes demonstrated fluid ingress and tissue ingrowth toward the electrode due to inadequate seal mechanisms. Inadequate seal design of the pacemaker generator and electrode junction leads to tissue ingrowth with fibroblastic proliferatiog chronic inflammation, and eventual pacemaker erosion.

Aged↗
PubMed1979

Shunt effect of carboxyhemoglobin.

Estimation of intrapulmonary blood shunt fraction requires accurate evaluation of pulmonary capillary, arterial, and mixed venous oxygen contents. The presence of carboxyhemoglobin, as well as methemoglobin and sulfhemoglobin, may lead to large errors in the calculated intrapulmonary blood shunt fraction. The errors are most pronounced at low values of carboxyhemoglobin and low values of true intrapulmonary shunt fraction.

Carboxyhemoglobin↗
PubMed1978

Documentation of vasomotor dysfunction by indicator dilution curve analysis.

Indocyanine green dye dilution curves with abnormal contours have been recorded in four patients with acute and critical illnesses using standardized recording methods. The abnormal curves are characterized by a high and prolonged concentration of dye occurring after the peak concentration. This altered contour can be detected by use of routine mathematical processing since the derived hemodynamic parameters are affected by the altered contour. A physiologic basis for the altered curve contour is proposed.

Acute Disease↗
PubMed1978

A shunt equation for estimating the splenic component of portal hypertension.

A modification of the Berggren pulmonary shunt equation was derived for use in estimating the splenic component of portal hypertension. It was used in nine patients, six of whom had sufficient decreases in portal flow and pressure after splenic artery and coronary vein ligation. The average decrease in portal flow was 52%.

Adult↗
PubMed1977

Physiologic profiles in circulatory support and management of the critically ill.

An automated system has been developed for measuring hemodynamic, oxygen transport and tissue utilization functions. Rapid measurement and data analysis of physiologic profiles by paramedical personnel allow prompt evaluation of altered cardiovascular function. Evaluation of physiologic function allows therapeutic interventions to be instituted on a timely basis, appropriately directed toward improvement of the measured cardiovascular abnormalities. Physiologic profile studies were performed on 1016 occasions in 580 patients during a three-year period and form the basis of this report. Although utilized on hospitalized patients, there are implications for use in evaluating and treating all critically ill patients.

Biological Transport, Active↗
PubMed1976

Sternal wire closure by an instrumental method.

Effective median sternotomy closure requires approximation of the sterum under appropriate tension in an expeditious manner. An instrument has been developed to provide tightening of applied sternal wires, allowing proper tension to be established. After tightening, the twisted wire is automatically trimmed by the instrument. The ease and reproducibility of this wire closure technic has allowed the method to be performed on a routine basis.

Stainless Steel↗