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Biomedical subjects

D Mascheroni

Publications and source records attributed to D Mascheroni.

29 records · Page 2Linked to original sources
PubMed1986

Low-frequency positive-pressure ventilation with extracorporeal CO2 removal in severe acute respiratory failure.

Forty-three patients were entered in an uncontrolled study designed to evaluate extracorporeal membrane lung support in severe acute respiratory failure of parenchymal origin. Most of the metabolic carbon dioxide production was cleared through a low-flow venovenous bypass. To avoid lung injury from conventional mechanical ventilation, the lungs were kept "at rest" (three to five breaths per minute) at a low peak airway pressure of 35 to 45 cm H2O (3.4 to 4.4 kPa). The entry criteria were based on gas exchange under standard ventilatory conditions (expected mortality rate, greater than 90%). Lung function improved in thirty-one patients (72.8%), and 21 patients (48.8%) eventually survived. The mean time on bypass for the survivors was 5.4 +/- 3.5 days. Improvement in lung function, when present, always occurred within 48 hours. Blood loss averaged 1800 +/- 850 mL/d. No major technical accidents occurred in more than 8000 hours of perfusion. Extracorporeal carbon dioxide removal with low-frequency ventilation proved a safe technique, and we suggest it as a valuable tool and an alternative to treating severe acute respiratory failure by conventional means.

Acute Disease↗
PubMed1986

Morphological response to positive end expiratory pressure in acute respiratory failure. Computerized tomography study.

Ten patients with acute respiratory failure (ARF), (4 pneumonia, 4 sepsis, 2 polytrauma), underwent computerized tomography (CT) of the lungs, (apex, hilum, base), at 5, 10, 15 cm H2O positive end expiratory pressure (PEEP). The ARF lungs, on CT scan, appeared as a patchwork of normal and dense areas with generally well defined boundaries. Most of the densities were found in the dependent regions. The areas of density were correlated with PaO2 (r = 0.51). The PEEP increase resulted in a significant expansion of total cross-sectional lung surface area. The dense areas decreased significantly at the hilum and base when increasing PEEP while the changes at the apex were not significant. The changes of density with PEEP were highly correlated with the changes in oxygenation (r = 0.91). In the individual patient, however, the modifications of gas exchange can not be entirely predicted from morphological changes, possibly due to a diversion of pulmonary blood flow.

Acute Disease↗
PubMed1986

Evaluation of tests for heparin control during long-term extracorporeal circulation.

Two coagulation tests, Recalcified Activated Clotting Time (RACT) and Hemochron, were compared with the activated partial thromboplastin time (APTT) in in vitro heparinization experiments and in patients heparinized for long term extracorporeal circulation (ECC) to determine their suitability as guidelines for heparin administration. All tests had good precision, with a small variability between methods. There was satisfactory correlation with the heparin level in vivo (r = 0.77 for RACT; r = 0.80 for Hemochron and r = 0.82 for APTT) too, while the in vitro r was always greater than or equal to 0.94. Nevertheless, APTT values for plasma heparin levels higher than 1.5 U/ml were markedly prolonged, with a large standard deviation, and often "unclottable". The good correlation between the three tests, makes it possible to substitute RACT and Hemochron for APTT, during long-term ECC.

Analysis of Variance↗
PubMed1984

The role of total static lung compliance in the management of severe ARDS unresponsive to conventional treatment.

A group of 36 patients with severe adult respiratory distress syndrome (ARDS) meeting previously established blood gas criteria (mortality rate 90%) became candidates for possible extracorporeal respiratory support [low frequency positive pressure ventilation with extracorporeal CO2 removal (LFPPV-ECCO2R)]. Before connecting the patients to bypass we first switched the patients from conventional mechanical ventilation with positive end expiratory pressure (PEEP) to pressure controlled inverted ratio ventilation (PC-IRV), and then when feasible, to spontaneous breathing with continuous positive airways pressure (CPAP). Forty eight hours after the patients had entered the treatment protocol, only 19 out of the 36 patients in fact required LFPPV-ECCO2R, while 5 were still on PC-IRV, and 12 were on CPAP. The overall mortality rate of the entire population was 23%. The only predictive value of success or failure of a particular treatment mode was total static lung compliance (TSLC). No patients with a TSLC lower than 25 ml (cm H2O)-1 tolerated either PC-IRV or CPAP, while all patients with a TSLC higher than 30 ml (cm H2O)-1 were successfully treated with CPAP. Borderline patients (TSLC between 25 and 30 ml (cm H2O)-1) had to be treated with PC-IRV for more than 48 h, or were then placed on LFPPV-ECCO2R if Paco2 rose prohibitively. We conclude that TSLC is a most useful measurement in deciding on the best management of patients with severe ARDS, unresponsive to conventional treatment.

Adolescent↗
PubMedDate not supplied

[Prostacyclin in the treatment of persistent fetal circulation syndrome].

Persistent pulmonary hypertension of the neonate (PPHN), described initially by Gersony in 1969 as persistent foetal circulation (PFC syndrome), results from a flawed transition from foetal to extrauterine pulmonary circulation. It is primarily characterised by persistence of, or return to, the suprasystemic pulmonary vascular resistance and pressure normally found in the foetus. The increased pulmonary pressure causes right to left shunting through the ductus arteriosus or the foramen ovale, or both. The resulting hypoxaemia and acidosis may produce further pulmonary vasoconstriction and lead to a vicious cycle of shunting, hypoxia and acidosis. Infants with a wide variety of underlying clinical conditions develop PPHN. This condition is reversible, but can cause very severe and unrelenting respiratory failure and ultimate death when uncontrolled. Although vasodilating agents, such as tolazoline, have been used with variable success in the treatment of PPHN, a generally acceptable therapy is still lacking. We report here the use of prostacyclin (epoprostenol, PGI2) in two infants with severe and refractory hypoxaemia secondary to pulmonary vasoconstriction.

Epoprostenol↗
PubMedDate not supplied

Constant mean airway pressure with different patterns of positive pressure breathing during the adult respiratory distress syndrome.

Twenty-one ARDS patients were divided into two groups of severity according to FIO2 and PEEP required to maintain an adequate gas exchange. The 10 most severe patients (group A) underwent continuous positive pressure ventilation (CPPV) (I/E 3:1) with the mean airway pressure maintained at 21 +/- 6.2 cmH2O. The PEEP values were 12.6 +/- 4.3 cmH2O during CPPV and 6.5 +/- 3.7 cmH2O during IRV (p less than 0.01). Eleven less severe ARDS patients (group B) underwent CPPV and positive pressure spontaneous breathing (CPAP) at constant mean airway pressure of 14.3 +/- 3.8 cmH2O. The PEEP was 7 +/- 2.5 cmH2O during CPPV and 14.9 +/- 4.3 cmH2O during CPAP (p less than 0.001). In five patients of each group, the SF6 shunt was measured as representative of true shunt. The results showed that gas exchange, including true shunt, and haemodynamics did not change between CPPV and IRV and between CPPV and CPAP tests. Taken with previous work on mean airway pressure, our results further support the concept that the main determinant of oxygenation and haemodynamics is the mean airway pressure, irrespective of the PEEP level and of the mode of ventilation.

Adolescent↗