Positive end-expiratory pressure and the damaged right ventricle. An experimental open versus closed chest study

Hemodynamic changes after isolated impairment of right ventricular function (produced by increasing afterload by temporary banding of the pulmonary artery) were studied in 22 ventilated pigs during increased levels of positive end-expiratory pressure (4, 8, 12, and 16 cm H2O). In the open chest group, application of positive end-expiratory pressure produced only a slight decrease of cardiac index. After right ventricular damage a decrease of cardiac index of more than 25% occurred only when higher levels of positive end-expiratory pressure were applied. In contrast to the open chest group, the closed chest group showed more distinct cardiovascular responses after positive end-expiratory pressure. In the damaged right ventricle with a positive end-expiratory pressure of 16 cm H2O, right ventricular end-diastolic pressure increased more than 100%. With positive end-expiratory pressure, cardiac index decreased 34% before and 47% after right ventricular damage. We conclude that positive end-expiratory pressure induces a more pronounced decrease in cardiac index if right ventricular function is impaired. During open chest conditions with lower levels of positive end-expiratory pressure, these changes are only small, however, and probably irrelevant. During closed chest conditions, the hemodynamic changes are much more pronounced. High right ventricular end-diastolic pressures resulting from impaired right ventricular contractility as well as from high levels of positive end-expiratory pressure may have an impact on biventricular function and right ventricular coronary driving pressure.     

Diagnostic value of load tests in the evaluation of nonspecific changes in the electrocardiogram

The paper describes the examinations of 353 patients with various cardiovascular pathologies and changes in the end-portion of the ECG ventricular complex. For that purpose potassium chloride, obsidan, orthostatic and hyperventilation tests were used. The examinations demonstrated that the ECG changes were of functional nature in 178 patients, of organic nature in 155 patients and of mixed nature in 20 patients which was important for reliable diagnostic and expertise conclusions.     

Endothelial cell loss due to repeated traumatic wound dehiscence after penetrating keratoplasty

A patient with keratoconus suffered two traumatic ruptures of her corneal graft wound, both of which were successfully repaired with restoration of graft clarity. There were also two apparently unrelated episodes of rejection. The endothelium was monitored by specular microscopy during this period. Our findings suggest that the insult to a transplanted cornea from an episode of rejection may be greater than that from traumatic wound rupture.     

Use of Telemetered Electrograms in the Assessment of Normal Pacemaker Function

The facility of direct real-time endocardial electrogram recording offered by newer pacemaker models can be helpful in the assessment of normal pacemaker function. Confirmation of the main hallmarks of sensing (amplitude, slew rate, and timing of the electrogram) can be achieved. Assessment of pacing capture also can be made; techniques for further analysis using external signal averaging can enhance this. The measurement of atrial and ventricular electrograms by telemetry has led to alterations in the protocol used at implantation to allow for the input impedance of the sensing circuit of the pacemaker. Accurate measurements of retrograde VA conduction times and confirmation of normal upper rate limit behavior of ODD pacemakers can be achieved simply and reliably using telemetered electrograms from the permanent pacemaker system.     

Cellular infiltrates in the target organs associated with acute graft-versus-host disease

Acute graft-versus-host disease (AGVHD) has been one of the major obstacles in successful bone marrow transplantation for many years. The histologic manifestations of AGVHD have been well defined but much less is known about the cellular infiltrates in the target organs during AGVHD, the structure of the inflammation is different in different target organs and is not necessarily similar to classical allograft rejection. This review covers, in addition to the histologic approach, the cytologic and functional approaches to the AGVHD associated with inflammatory cells.     

Expulsive hemorrhage in cataract extraction

This article reports on six cases of massive expulsive hemorrhage during intracapsular cataract extraction (incidence = 0.17%). Some of the known risk factors are old age, hypertony, glaucoma, and an insufficient decrease in intraocular pressure following oculopression prior to surgery. Drainage of the suprachoroidal hemorrhage, closure of the wound and reformation of the anterior chamber are necessary surgical interventions. In one case the treated eye was saved and a visual acuity of 0.1 achieved.     

Cast-brace treatment of ankle sprains

Forty-two severely sprained ankles treated by a cast-brace have been reviewed. This method was devised to avoid the disadvantages of immobilization. Diagnosis was based on the history and clinical signs. Strain films were taken in 31 patients but it is submitted that this investigation may be misleading unless general anaesthesia is used. The results of the treatment by cast-brace compare favourably with those by other methods and it is considered that patients were able to return to sport in a shorter time.