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Biomedical subjects

D Dreyfuss

Publications and source records attributed to D Dreyfuss.

82 records · Page 5Linked to original sources
PubMed1986

Sedative effects and impaired learning and recall after single oral doses of lorazepam.

Seven healthy subjects received oral placebo, 1.5 mg lorazepam, or 3.0 mg lorazepam in a single-dose, three-way crossover study. Plasma lorazepam concentrations and subjects' self-rated sedative effects were evaluated at multiple points during 24 hours after each dose. Information acquisition and recall was studied by use of a 16-item word list at 3 and 24 hours after dosing. Lorazepam plasma concentrations were proportional to dose. Self-rated sedation was maximal 2 to 3 hours after lorazepam dosing, persisted for 8 hours, and was dose dependent in intensity; no significant sedation occurred with placebo. At 3 hours after placebo dosing, subjects learned a mean 96% of words presented during six trials; this was reduced to 79% and 62% after lorazepam, 1.5 and 3.0 mg, respectively (F = 6.2; P less than 0.02). Twenty-four hours after placebo, subjects recalled 92% of words presented the previous day, then improved to 99% after six relearning trials. After 1.5 and 3.0 mg lorazepam, however, only 52% and 44% of words were initially recalled from the previous day. Thus single oral doses of lorazepam within the therapeutic range produce dose-dependent sedation and impairment of information acquisition and recall.

Administration, Oral↗
PubMed1986

High-frequency ventilation in the management of tracheal trauma.

Two cases of rupture of the trachea were treated by surgical repair. Intraoperative and postoperative ventilation was managed with high-frequency ventilation. This mode of ventilation afforded good intraoperative exposure and support as well as good postoperative ventilation despite pulmonary contusion without requiring inflation of the endotracheal tube cuff against tracheal suture lines. We recommend high-frequency ventilation in the management of tracheobronchial trauma intraoperatively and postoperatively, because it allows good ventilation despite pulmonary contusion without high positive airway pressures and without the necessity for inflation of the endotracheal tube cuff against a tracheal suture line.

Adult↗
PubMed1986

Kinetics and dynamics of single doses of oxazepam in the elderly: implications of absorption rate.

Five healthy elderly volunteers aged 64 to 67 years and 12 healthy young subjects aged 23 to 44 years received single 30 mg oral doses of oxazepam in two different dosage forms (two 15 mg tablets or one 30 mg capsule) on two occasions in a random crossover sequence, with at least 1 week elapsing between trials. In both age groups, rate of oxazepam absorption of the capsule form of the drug was significantly slower than that of the tablets. Peak plasma concentrations were lower and were delayed longer with the capsule form; however, the relative extent of oxazepam absorption did not differ between preparations in either age group. Clinical self-ratings in the elderly group, based on visual analog scales, were consistent with the delayed onset of sedative effects that is associated with the capsule form of administration. Kinetic comparisons in the two groups indicated a significantly prolonged oxazepam elimination half-life with the tablet (p less than .001) and with the capsule (p less than .06) and a trend (p less than .08) toward reduced oxazepam clearance in the elderly. The delayed absorption of oxazepam from the capsule was found in both the young and elderly groups.

Administration, Oral↗
PubMed1985

[Fatal massive intravascular coagulation during phlebography. Responsibility of epsilon-aminocaproic acid?].

The occurrence during phlebography of massive intravascular coagulation involving the inferior vena cava, the right cardiac cavities and the entire pulmonary arterial network suggested that epsilon-aminocaproic acid administered before phlebography was responsible for this complication. The mechanisms of reactions to contrast media are still poorly understood, but these reactions are known to include, in some cases, disseminated intravascular coagulation. This phenomenon was histologically demonstrated in our patient, and it may be suggested that its strong enhancement by the antifibrinolytic agent had resulted in the fatal accident. In view of the possibility of such lethal reactions, the advisability of administering epsilon-aminocaproic acid--a drug widely used in France for the prevention and treatment of contrast media reactions--should be reconsidered.

Adult↗
PubMed1985

Intermittent positive-pressure hyperventilation with high inflation pressures produces pulmonary microvascular injury in rats.

The mechanisms by which intermittent positive-pressure ventilation with high inflation pressure (HIPPV) induces pulmonary edema remain uncertain. In this study we investigated the physiologic and anatomic changes related to HIPPV at 45 cmH2O peak inspiratory pressure in rats. Edema was quantified by the extravascular lung water obtained from postmortem weighing and by 22Na distribution space. Pulmonary microvascular permeability was assessed by dry lung weight and fractional albumin uptake. After only 5 min of HIPPV, there was a significant increase in Na space, dry lung weight, and fractional albumin uptake when compared with that in control rats mechanically ventilated at 7 cmH2O peak inspiratory pressure. These changes suggest that edema may be due at least in part to alterations in microvascular permeability. Moderate peribronchovascular edema was present. At the ultrastructural level, some endothelial cells were found detached from their basement membrane. This lesion has been previously described in other types of pulmonary microvascular injury. The above findings remained almost unchanged after 10 min of HIPPV. After 20 min of HIPPV, we observed the outpouring of a high protein content alveolar flooding accompanied by a further significant increase in fractional albumin uptake and dry lung weight. Additional anatomic damage appeared including epithelial lesions and hyaline membranes. Thus, HIPPV edema presents all the features of high permeability edema. These results may be of concern in the ventilatory management of patients with acute respiratory failure in order to avoid additional damages induced by local overinflation.

Animals↗
PubMed1983

[Increase in partial arterial carbon dioxide pressure due to parenteral nutrition during artificial ventilation].

The influence of increased enteral caloric intakes on respiratory gas exchanges was evaluated in 6 patients (5 men, 1 woman; mean-age: 54 years) in steady state and requiring continuous ventilatory support. Oxygen consumption (VO2), carbon dioxide production (VCO2), respiratory quotient (R), determined using an open circuit indirect calorimetric method, and arterial blood gases were measured on two consecutive days while ventilation conditions were unchanged. On the first day, the patients received a water diet only and on the following day an enteral caloric load (1491 +/- 65 Kcal/m2/24 h). The results showed a significant increase in VO2 (p less than 0.05) and R (p less than 0.001) and a rise in VCO2 from 106 +/- 4 to 139 +/- 9 ml/mn/m2 (p less than 0.01). The rise in VCO2 induced an increase of arterial carbon dioxide tension (PaCO2) from 26.3 +/- 1.6 to 34.4 +/- 2.4 mmHg (p less than 0.001). This study showed that because of the constancy of alveolar ventilation, the enteral nutrition-related increase of VCO2 is responsible for a PaCO2 increase and emphasized the need for adjusting artificial ventilation to any change in caloric intake in patients supported with mechanical ventilation.

Carbon Dioxide↗
PubMed1980

Medical and surgical consultations to a general hospital psychiatric unit.

This study reviews 563 medical and surgical consultations to a general hospital psychiatric unit over three years. In addition to an analysis of the consultations by service and month, consulted patients are compared with nonconsulted patients by age, sex, and diagnosis. Parallels are drawn to psychiatric consultations are reported in the consultation-liaison literature to medical and surgical patients. Two important findings from the present study are that depressed patients received significantly (P less than 0.01) fewer consultations than expected, and that 49% of one year's consultations were for active medical problems not related to the reason for psychiatric admission.

Adult↗