Search PubMed⌕ Search

Biomedical subjects

G A Schmidt

Publications and source records attributed to G A Schmidt.

At least 37 records · Page 2Linked to original sources
PubMed1993

Metered-dose inhaler versus nebulized albuterol in mechanically ventilated patients.

In nonintubated patients, beta 2-agonist bronchodilators are equally effective when delivered by metered-dose inhalers (MDI) or nebulizers (NEB). The delivery of these drugs by MDI to intubated, mechanically ventilated patients has become a widespread practice. To compare the efficacy of the two delivery systems and establish optimal dosing, we prospectively randomized 10 mechanically ventilated patients, with increased airways resistance, to receive albuterol by either MDI or nebulizer in incrementally higher doses. After a 4-hr washout, patients were crossed-over to receive the drug by the alternative route of administration. Albuterol delivered by NEB to a total dose of 2.5 mg reduced the inspiratory flow-resistive pressure (peak-pause airway pressures) from 21.5 +/- 5.7 to 17.6 +/- 5.4 cm H2O (p < 0.01). Nebulized albuterol at cumulative doses of 7.5 mg led to further reductions in 8 of 10 patients (p < 0.1), but led to toxic side effects in 4 of them; in the remaining 6 patients toxicity occurred at a cumulative dose of 15.0 mg. By contrast, albuterol in cumulative doses reaching 100 puffs (9 mg) from an MDI administered into an endotracheal tube adapter did not significantly reduce resistive pressures, and produced no toxicity. We conclude that nebulized albuterol provides objective physiologic improvement, while albuterol administered by MDI through an endotracheal tube adapter has no effect in mechanically ventilated patients with airflow obstruction. Nebulizer treatments can and should be titrated to higher-than-conventional doses, using toxic side-effects and physiologic response to guide therapy.

Adult↗
PubMed1993

Fortuitous esophageal intubation.

Esophageal malposition is a potentially disastrous complication of attempted airway intubation. We report an unusual case in which a promptly recognized esophageal intubation aided detection of a perforated gastric ulcer. After the endotracheal tube was repositioned and the ulcer was surgically repaired, our patient had an excellent outcome.

Esophagus↗
PubMed1993

Inverse ratio ventilation in ARDS. Improved oxygenation without autoPEEP.

Inverse ratio ventilation and related ventilatory modes (eg, pressure release ventilation) have been applied to patients with the adult respiratory distress syndrome (ARDS) with apparent beneficial effects on arterial oxyhemoglobin saturation. While several mechanisms of improved gas exchange have been postulated, many intensive care physicians believe that the development of occult PEEP (autoPEEP; intrinsic PEEP) leads to the observed rise in oxygen saturation. We report here our findings in a patient whose improved oxygenation on inverse ratio ventilation could not be attributed to autoPEEP.

Adolescent↗
PubMed1993

Pleural effusion masquerading as myocardial infarction.

The effects of pleural effusions on the ECG have not been well studied. We report herein the case of a patient with extreme QRS axis deviation mimicking acute myocardial infarction. Thoracentesis caused the return of a more normal axis.

Aged↗
PubMed1991

Cardiac tamponade and contralateral hemothorax after subclavian vein catheterization.

A patient developed life-threatening cardiac tamponade and contralateral hemothorax after insertion of a subclavian catheter in the operating room. Contrast was infused through the catheter, demonstrating its malposition in the pericardial space. Contrast infusion was valuable in evaluating this complication of central line placement.

Cardiac Tamponade↗
PubMed1990

Therapeutic use of intrinsic positive end-expiratory pressure.

A patient with acute hypoxemic respiratory failure undergoing mechanical ventilation with PEEP developed significant obstructive airway disease. We found that intrinsic PEEP, substituted for externally applied PEEP, could maintain oxygenation. The increased inspiratory/expiratory time ratio, which resulted in the development of intrinsic PEEP, beneficially reduced airway pressures.

Airway Obstruction↗
PubMed1989

Acute or chronic respiratory failure. Assessment and management of patients with COPD in the emergency setting.

Patients with acute or chronic respiratory failure exhibit severe pulmonary impairment as a baseline characteristic. Additional minor insults can precipitate cardiopulmonary failure that requires hospital admission and possibly mechanical ventilation. Our approach to these patients emphasizes evaluation of the imbalance between neuromuscular competence and mechanical load on the respiratory system. In this way, reversible factors can be identified and corrected before they progress to inspiratory muscle fatigue and respiratory failure. For cases in which deterioration is inexorable, guidelines for mechanical ventilation are given and approaches to eventual liberation from the ventilator are reviewed.

Arrhythmias, Cardiac↗
PubMed1989

Computerized smoking cessation program for the worksite: treatment outcome and feasibility.

This study demonstrated the effectiveness of a computer-delivered smoking cessation program for the worksite. 58 VA Medical Center employees were randomly assigned to a computer group (computerized nicotine fading and stop-smoking contest) or a contest-only group. In comparison with the contest-only group, the computer group had nonsignificantly higher abstinence rates across follow-up, had marginally lower CO levels at the 3- and 6-month follow-ups, and smoked cigarettes with lower nicotine levels at the 10-day and 6-month follow-ups.

Adult↗
PubMed1985

Effects of encainide on the determinants of cardiac excitability in sheep Purkinje fibers.

Encainide is a benzanilide derivative that is effective against ventricular arrhythmias but, at times, may be arrhythmogenic. The microelectrode technique of intracellular current application and transmembrane voltage recording was used to study the effects of encainide, in a concentration equivalent to a clinically effective antiarrhythmic plasma level, on the determinants of cardiac excitability in sheep Purkinje fibers. A rapid, on-line computerized data analysis system was used to track the alterations in the active and passive membrane properties relevant to excitability in time. Cardiac excitability was defined experimentally in terms of the current required to attain threshold and/or the shift in strength- or change-duration curves. Encainide produced multiphasic changes in cardiac excitability, the final state of excitability depended on the balance between altered passive and active membrane properties. Encainide could enhance excitability by increasing membrane and slope resistance without altering the nonlinearities of the current-voltage relationship despite an actual depression of the sodium system. Encainide could decrease excitability by 1) depressing the sodium system; 2) decreasing membrane resistance without altering the nonlinearities of the subthreshold current-voltage relationship; 3) altering the nonlinearities of the current-voltage relationship; and 4) by a combination of these actions. During washout, excitability could remain altered despite a return of descriptive parameters such as the maximal rate of rise of phase 0, overshoot and action potential duration to normal. The study demonstrated the importance of time-related changes of an antiarrhythmic drug at a constant concentration. The results explain, in part, the antiarrhythmic actions and arrhythmogenic potential of encainide.

Action Potentials↗
PubMed1978

[Current problems in the pathophysiology of the adrenal glands and its clinical importance].

In recent years new knowledge on the pathophysiolgy of the parathyroid gland has led to a series of not unimportant consequences for the endocrinological clinic. To this belongs the glandular translocation which under certain circumstances is regarded as favourable and the principal practicability so which is without any question. In certain, above all urologically conditioned clinical pictures with consecutive stimulation of the parathyroid secretion an inhibition effect on the parathyroid glands which can be evoked by drugs is discussed. Here the problem is a possibly significant preventive measure. The question of the maintained or disturbed euparathyroidism must be interesting in such cases, in which alone from the result of the conventional calcium-metabolic diagnostics an obligatory evidence remains questionable. Difficulties are above all in such cases, where the transitions of a functional adaption mechanism to an autonomized process with own laws may be present or it must be feared that the overloaded glandular function comes to an end. On the basis of own findings the authors adopt a definite attitude to these problems.

Adenoma↗
PubMed1978

[Position of tylopoda in the system of placental mammals].

Anatomical features of the Tylopoda are determined to a great extent by the convergence with the Ruminantia. The dental system adapted to the double mastification of plant food. The convergent character of the structure of limbs follows from the reduction of carpal and tarsal bones in the Tylopoda and their presence in the Ruminantia. The Ruminantia have no mandibular angular processes which are present in the Tylopoda. In the Tylopoda, the foramina in the transversal processes of cervical vertebrae from a canal by which the vertebral artery opens in the brain. In the Ruminanta there is no such a canal. The embryonic development of camels is characterized by the promitive features of provisory organs. The mating of camels occurs in winter, a feature probably showing that they have preserved the reproduction cycle of the Southern Hemisphere animals.

Anatomy, Comparative↗
PubMed1977

[Catamnestic studies on the prodomal phase of myocardial infarct].

In a retrospective study by means of a half-standardized method of interview in 154 patients with acute myocardial infarction and in a control group of the same age (n = 100) anamnestic data were established, particularly taking into consideration the preinfarction phase. 27% of the patients were surprised by an acute myocardial infarction without prodromal symptoms, in 32% the first occurrence of complaints of angina pectoris was during the last two months before the infarction. 41% had a preexisting angina pectoris which usually showed a crescendo-course with increasing approximation to the infarction. More than half of the patients reported on physical activity or/and emotional stress as causal factors of the preinfarction complaints. The correlation with the localisation of the infarction showed above all an occurrence of the prodromal symptoms in infarctions of the anterior wall and in lesions of the myocardium which in most cases could be ascertained only enzymatically. A greater accumulation of the prodromi was furthermore found in younger patients, in hypertension and preexisting restriction of the heart function. 70% of the patients with warning symptoms consulted a physician because of their heart complaints. In the control group 22% of the persons reported on heart complaints.

Acute Disease↗