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Biomedical subjects

E Knobel

Publications and source records attributed to E Knobel.

At least 19 recordsLinked to original sources
PubMed1992

[Post infarction ventricular septal defect. Echocardiographic analysis of patients treated with positive end-expiratory pressure].

Interventricular septal rupture is a life-threatening complication occurring in 0.5 to 1.0% of patients following acute myocardial infarction and often results in right and left ventricular failure. This study aimed at evaluating the echocardiographic effects of PEEP on right (RV) and left (LV) ventricular dimension in three patients who developed a postinfarction septal defect and in whom acute respiratory failure was a preterminal event. The effects of PEPP on the heart remain controversial. We observed in all three patients a sudden large increase in RV dimensions and hence, probably through ventricular interdependence, a proportional decrease in LV dimensions. The progressive leftward septal displacement with increasing levels of PEEP probably contributed to reduce LV compliance. We concluded that PEEP therapy in this group of patients had no proven beneficial effects and probably contributed to further RV dilatation and failure.

Aged↗
PubMed1990

[Neurophysiological evaluation using multimodal sensory evoked potentials in patients in coma: general aspects].

Noninvasive sensory evoked potentials (SEP) performed at bedside in the Intensive Care Unit for patients in coma can be helpful in establishing both a diagnosis and a prognosis. Based on a more than 6-year experience on this subject, the authors discuss general aspects concerning these EP, their probable known generators, and propose a classification depicting different aspects observed for flash visual EP (F-VEP), brainstem auditory EP (BAEP), and median nerve somato-sensory EP (SSEP). Isolated, SSEP shows the best diagnostic and prognostic performance. Nevertheless, the authors consider that multimodality SEP are even better than any isolated EP study; cross-correlating information generated through a horizontal (F-VEP), a vertical (SSEP), and a pathway focusing brainstem in greater detail (BAEP) allows the neurophysiological establishment of the level of lesion in the CNS from a better perspective; besides, SEP can help setting the diagnosis of brain (encephalic) death, and the diagnosis of particular problems concerning each pathway. Notwithstanding, most important is prognosis definition, and the findings are summarized. Abnormal BAEP implies bad prognosis, as would be expected considering the severity of a brainstem lesion; on the other hand, a normal BAEP per se does not allow a precise definition, resting on other EP the role prognosis characterization. SSEP if bilaterally normal or only mildly abnormal imply good prognosis; bilateral absence of SSEP thalamo-cortical components has always carried a bad prognosis, since younger patients may at best evolve into a persistent vegetative state; SSEP intermediary results are more often accompanied by variable evolution. FVEP results parallel those of SSEP.

Coma↗
PubMed1990

[Staphylococcus aureus endocarditis in a puerperal woman with mitral and tricuspid valve prolapse].

A 17-year-old woman with mitral and tricuspid valve prolapse and myxomatous degeneration presented puerperal infection by Staphylococcus aureus with clinical picture of sepsis and multiple septic embolism (right eye, left thumb, spleen, and left calf). She underwent total hysterectomy on the 10th day postdelivery and right eye enucleation on the 16th. Temporary total AV block occurred on the 14th day with temporary external pacing during the next couple of days. Acute endocarditis with acute mitral regurgitation was diagnosed on the 13th day, demanding immediate valve replacement. On the 46th day she developed moderate tricuspid valve regurgitation due to another episode of endocarditis. Final clinical discharge took place on the 62nd day after antibiotic therapy completion.

Adolescent↗
PubMed1989

Reliability of right atrial pressure monitoring to assess left ventricular preload in critically ill septic patients.

Right atrial pressure (RAP) can be used as a guide to fluid therapy in critical care settings. RAP and pulmonary capillary wedge pressure (WP) were measured in 27 septic patients without cardiac disease and on mechanical ventilation. An r of .61 was obtained with a regression line defined by the equation WP = 7.38 + (0.53 x RAP) +/- 3.15. However, a large SD of data points can invalidate the clinical usefulness of this equation. The reliability of various RAP interval values in predicting optimal WP was then studied in these patients. We concluded that RAP values less than or equal to 5 mm Hg were highly specific (97%) in predicting low or normal WP (less than or equal to 12 mm Hg).

Adult↗
PubMed1975

Effects of delta9-tetrahydrocannabinol and cannabinol in man.

The interaction of delta9-tetrahydrocannabinol (delta9-THC) and cannabinol (CBN) was studied in man. Five male volunteers were given placebo, 50 mg CBN, 25 mg delta9-THC, 12.5 mg delta9-THC + 25 mg CBN, and 25 mg delta9-THC + 50 mg CBN (orally). Administrations were spaced 1 week apart. With physiological measures, delta9-THC produced an increase in heart rate while CBN did not. When combined, no change of the delta9-THC effect occurred. No changes occurred on the electrocardiogram, blood pressure, or body temperature. With psychophysical measures no changes occurred in pain thresholds or skin sensitivity as a function of drug treatment. In time estimates of the passage of 1 minute, delta9-THC alone produced underestimates of the passage of 1 minute and CBN alone had no effect. In combination the two drugs had a tendency to produce significant overestimates and underestimates of the passage of 1 minute. On a 66-item adjective-pair drug reaction scale, the volunteers reported feeling drugged, drunk, dizzy, and drowsy under the delta9-THC condition, but not under the CBN condition. With combined drug treatment, volunteers reported feeling more drugged, drunk, dizzy, and drowsy than under the delta9-THC condition alone. None of the drug treatments produced significant changes on other items which included items on perception, emotion, cognition and sociability. It appears that CBN increases the effect of delta9-THC on some aspects of physiological and psychological processes, but that these effects are small and cannot account for the greater potency which has been reported when plant material is used.

Administration, Oral↗