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Biomedical subjects

R Rossaint

Publications and source records attributed to R Rossaint.

180 records · Page 10Linked to original sources
PubMed1993

Inhaled nitric oxide: its effects on pulmonary circulation and airway smooth muscle cells.

Nitric oxide (NO), an endothelium-derived relaxing factor synthesized from L-arginine by the enzyme NO synthase, has been identified as an important, short-acting, endogenous vasodilator. In patients with pulmonary hypertension, inhaling a low dose of NO as a gaseous vasodilator has been shown to induce selective vasodilation in ventilated lung areas. It achieves this without the disadvantages attributed to systemically infused vasodilators e.g. systemic vasodilation and an increase in pulmonary right-to-left shunt with a consecutive fall in PaO2. Thus, inhaled NO reduces pulmonary hypertension in the severe adult respiratory distress syndrome and in persistent pulmonary hypertension of the newborn, and improves arterial oxygenation by redistributing pulmonary blood flow away from the shunt and towards areas with almost normal ventilation/perfusion ratios. The bronchodilatory effect of NO may be an alternative therapy for treating asthma and bronchospasm.

Administration, Inhalation↗
PubMed1992

Major thoracic surgery during long-term extracorporeal lung assist for treatment of severe adult respiratory distress syndrome (ARDS).

Surgery in patients treated with extracorporeal lung assist (ELA) carries a high risk of life threatening bleeding complications caused by the need for systemic anticoagulation. A case report describing a successful surgical intervention for the repair of a broncho-pleural leakage by thoracotomy during ELA is presented. A newly developed heparin coated extracorporeal system was used in a patient being treated for severe adult respiratory distress syndrome (ARDS) after left sided pneumectomy. The heparin coated system allowed discontinuation of systemic heparinization intraoperatively without coagulation complications related to the extracorporeal system. This procedure was followed by resolution of the ARDS.

Adult↗
PubMed1992

Positive end-expiratory pressure reduces renal excretion without hormonal activation after volume expansion in dogs.

Controlled mechanical ventilation (CMV) with positive end-expiratory airway pressure decreases urine output and renal sodium excretion. This study investigates--independent of surgical stress, general anesthesia, and sedation--the influences of antidiuretic hormone, atrial natriuretic peptide, plasma renin activity, and aldosterone on decreased urine output and renal sodium excretion during CMV with positive end-expiratory airway pressure. Hemodynamic, renal, and hormonal parameters were measured over a 4-h period in six trained, nonanesthetized, chronically tracheotomized dogs under two conditions: 1) control: hours 1-4, spontaneous breathing at continuous positive airway pressure of 4 cmH2O; and 2) CMV 20: hour 1, continuous positive airway pressure of 4 cmH2O; hours 2 and 3, CMV with a mean airway pressure of 20 cmH2O; and hour 4, continuous positive airway pressure of 4 cmH2O. Throughout the experiments, 0.5 ml.kg body weight-1.min-1 balanced electrolyte solution was administered intravenously. During the 2nd and 3rd h of CMV 20, urine volume decreased by 43% and sodium excretion decreased by 44% when compared with control values (P less than 0.05). The glomerular filtration rate decreased from 4.4 +/- 0.1 to 3.9 +/- 0.1 ml.kg-1.min-1 (P less than 0.05) during the 2nd h and from 4.4 +/- 0.1 to 4.1 +/- 0.1 ml.kg-1.min-1 (P less than 0.05) during the 3rd h of CMV 20. Fractional sodium excretion decreased from 4.7 +/- 0.3% to 2.9 +/- 0.2% (P less than 0.05) during the 2nd h and from 7.5 +/- 0.3% to 4.6 +/- 0.2% (P less than 0.05) during the 3rd h of CMV 20, compared with values during the control period.(ABSTRACT TRUNCATED AT 250 WORDS)

Aldosterone↗
PubMed1992

ACE inhibition facilitates sodium and water excretion during PEEP in conscious volume-expanded dogs.

Increased activity of the renin-angiotensin system may be involved in sodium and water retention during controlled mechanical ventilation (CMV) with positive end-expiratory pressure (PEEP). We therefore evaluated renal, hemodynamic, and hormonal effects of an acute angiotensin-converting enzyme inhibition (ACEI) during PEEP and extracellular volume expansion in five trained chronically tracheotomized dogs. Three protocols were performed: control, 4 h spontaneous breathing with continuous positive mean airway pressure (Paw) of 4 cmH2O (CPAP 4); CMV 20, CPAP for 1st h, CMV with 20 cmH2O Paw for 2 h (2nd and 3rd h), and 1 h of CPAP (4th h); and CMV20-ACEI, ACEI (Ramipril, 2 mg/kg body wt) followed by the same protocol as in CMV 20. During control, sodium excretion (UNaV) and urine volume (V) increased continuously to 56.2 +/- 2.7 (SE) mumol.min-1.kg body wt-1 and 482 +/- 23 microliters.min-1.kg body wt-1, respectively. UNaV and V increased less during PEEP in CMV 20 and CMV 20-ACEI. However, significantly more sodium and water were retained in CMV 20 than in CMV 20-ACEI (2.3 +/- 0.3 vs. 1.0 +/- 0.3 mmol/kg body wt, and 20 +/- 3 vs. 11 +/- 2 ml/kg body wt) because of a decrease of glomerular filtration rate and fractional UNaV in CMV 20. Heart rate did not change in control, CMV 20, or CMV 20-ACEI. Mean arterial pressure increased during control by 13 mmHg, did not change during CMV 20, and was decreased by 7 mmHg in CMV 20-ACEI.(ABSTRACT TRUNCATED AT 250 WORDS)

Angiotensin-Converting Enzyme Inhibitors↗
PubMed1992

Extracorporeal lung assist with heparin-coated systems.

Extracorporeal lung assist (ELA) has been recommended for the treatment of ARDS if conventional therapy fails. However, the need for nearly complete anticoagulation is a major risk factor for hemorrhagic complications. We describe our experience with 13 ARDS patients treated with ELA using heparin-coated systems (Carmeda). Maintaining partial thromboplastin time and activated clotting time within or close to the normal range, even major surgery (20 thoracotomies and 2 laparotomies) could be performed without undue bleeding complications related to anticoagulation during extracorporeal support. Eight of the 13 patients survived. The use of heparin-coated systems allows prolonged ELA with nearly physiological coagulation function, permitting major surgical intervention. It enhances the safety margin of extracorporeal gas exchange and may ultimately extend its indications.

Adult↗
PubMed1988

Extracorporeal CO2-removal with a heparin coated artificial lung.

Treatment of severe acute respiratory failure with extracorporeal gas exchange necessitating near complete systemic anticoagulation requires a delicate balance to be maintained between disseminated intravascular coagulation and hemorrhagic complications. The present study describes our first experience using a heparin coated extracorporeal artificial lung and circuitry during clinical extracorporeal CO2 removal. In spite of a partial thromboplastin time and activated clotting time within or close to the normal range, neither laboratory evidence for disseminated intravascular coagulation induced by the extracorporeal circuit nor thrombi in the pulmonary vasculature were found. Scanning electron microscopy of the heparin coated hollow fiber gas exchanger demonstrated only minor deposits on the surface. Use of a heparin coated artificial lung may enhance the margin of safety of extracorporeal gas exchange and ultimately broaden its indications.

Acute Disease↗
PubMed1987

[Abdominal aortic aneurysm--is a conservative attitude still justified? Experiences with 56 emergency and 128 elective surgical patients from the anesthesiological and vascular surgery viewpoints].

A retrospective analysis was undertaken of a consecutive series of 184 patients operated on between 1.1. 1984 and 31. 12. 1985 for aneurysm of the abdominal aorta. Rupture of the aneurysm had occurred in 56 patients (aged 70 +/- 9 yrs), 47 (aged 66 +/- 9 yrs) had symptoms of an aneurysm, and 81 (aged 66 +/- 5 yrs) were operated on electively. The highest peri-operative hospital mortality rate, of 35.9%, was among the group with rupture (compared with 8.5% for the symptomatic group and 1.2% for the elective one). The period of intensive care in surviving patients was highest in the rupture group, at 8 +/- 17 days, compared with 3 +/- 2 in the symptomatic and 3 +/- 3 days in the elective group. Duration of postoperative hospital stay was 20 +/- 13, 15 +/- 7 and 13 +/- 6 days, respectively, in the three groups. Half of the patients also had arterial obstructive disease, arterial hypertension and/or coronary heart disease (25% had had an infarct according to the history, 8% more than one). A third of the patients received or should have received treatment for lung or respiratory tract disease, heart failure and/or cardiac arrhythmias. The thirty-fold increase in mortality rate for an emergency operation over that for elective surgery, together with the higher costs and longer hospital treatment, as well as the reduced probability of survival with conservative treatment speak for an aggressive approach towards elective surgery after optimal pre-operative treatment.

Adult↗
PubMedDate not supplied

Vibration sense testing with a 128-Hz tuning fork as a tool to determine recovery from epidural neuraxial block.

BACKGROUND AND OBJECTIVES: Vibration sense testing using a 128-Hz tuning fork is a commonly used test in the diagnosis of dorsal horn dysfunction and polyneuropathy. In this open, prospective study, we tested the hypothesis that vibration sense testing is a sensitive and specific method to assess recovery from epidural block. METHODS: Recovery from epidural block was evaluated in 81 patients undergoing cesarean delivery or vein stripping by comparing the use of a 128-Hz tuning fork with the results of conventional evaluation of block recovery. Conventional block recovery testing included Bromage-Score, formal muscle power testing according to the British Medical Research Council, pinprick testing, and warm/cold testing. Epidural blocks were performed by the same anesthesiologist using ropivacaine and sufentanil via an epidural catheter. After obtaining baseline values, an epidural anesthetic was performed and patients were tested every 30 minutes until complete recovery from the block was documented with all examined methods. Statistical analysis was performed to compare the results of the different methods to the time at which baseline values of vibration sense were reached. RESULTS: At the time vibration sense testing returned to baseline, there was no residual motor block according to the Bromage Score in 100% of the patients and no residual block for foot flexion and extension. Twelve percent of the patients showed a minimal lack of strength in the quadriceps muscle and 11% had residual sensory anesthesia to pinprick below L5/S1. CONCLUSIONS: Based on our observations, recovery of vibration sense corresponds with recovery of motor block after epidural anesthesia and may serve as an easy means of documenting recovery with a single test before discharge.

Adult↗