Negative pressure ventilation versus conventional mechanical ventilation in the treatment of acute respiratory failure in COPD patients

This case-control study was aimed to evaluate the effectiveness of negative pressure ventilation (NPV) versus conventional mechanical ventilation (CMV) for the treatment of acute respiratory failure (ARF) in patients with chronic obstructive pulmonary disease (COPD) admitted to a respiratory intermediate intensive care unit (RIICU) and four general intensive care units (ICU). Twenty-six COPD patients in ARF admitted in 1994-95 to RIICU and treated with NPV (cases) were matched according to age (+/-5 yrs), sex, causes triggering ARF, Acute Physiology and Chronic Health Evaluation (APACHE) II score (+/- 5 points), pH (+/-0.05) and arterial carbon dioxide tension (Pa,CO2) on admission with 26 patients admitted to ICU and treated with CMV (controls). The primary end points of the study were inhospital death for both groups and the need for endotracheal intubation for cases. The secondary endpoints were length and complications of mechanical ventilation and length of hospital stay. The effectiveness of matching was 91%. Mortality rate was 23% for cases and 27% for controls (NS), five cases needed endotracheal intubation, four of whom subsequently died. The duration of ventilation in survivors was significantly lower in cases than in controls, with a median of 16 h (range 2-111) versus 96 h (range 12-336) (P<0.02), whereas the length of hospital stay was similar in the two groups, with a median of 12 days (range 2-47) for cases vs 12 days (range 3-43) (NS) for controls. No complications were observed in cases, whereas three controls developed infective complications. These results suggest that negative pressure ventilation is as efficacious as conventional mechanical ventilation for the treatment of acute respiratory failure in patients with chronic obstructive pulmonary disease and that it is associated with a shorter duration of ventilation and a similar length of hospital stay compared with conventional mechanical ventilation.

[Treatment of postoperative pain with non-narcotic drugs; evaluation of lysine acetylsalicylate in high doses. Double-blind controlled study]

Further work on the treatment of postoperative pain with non-narcotic analgesics involving an investigation of the effect of twice the customary dose of lysine acetylsalicylate in a double-blind trial versus meperidine is reported. In addition to subjective and objective pain, the parameters included blood pressure, pulse rate, breathing rate, sweating, pupil diameter, nausea, vomiting, somnolence, hiccuping feeling of cold, erythema, dizziness, and nasograstric sound intolerance. Application of Wilcoxon's non-parametric tests and the chi-square test showed that the drug was as good as or better than meperidine with regard to pain, and performed very well overall with respect to the other parameters. The conclusion is drawn that its administration in high doses is justified in many patients subjected to general surgery.

[The role of the myocardial depressant factor in the pathogenesis of the shock]

Examination of the pathogenesis of shock has directed attention to the microcirculation, the kidneys, and the lungs. Today, apart from other tissues and organs, particularly the splanchnic organs, the pancreas is also incriminated. The lysosomes (also present in other tissues) and zymogen granules it contains are responsible, during the ischaemia and hypoxia typical of shock, for the instigation of a process of cell autolysis that releases enzymes and frequently toxic protein fragments into the bloodstream. These include myocardial depressant factor (MDF), whose physical, chemical and biological identification and rôle are now fairly clear. First described by Brand & Lefer in 1966, MDF has been explored by Lefer and other workers at both the experimental and clinical level. An account is given of the main researches that have led to the determination of the characteristics and action of MDF in numerous types of shock, the pattern of its formation, and the routes by which it is introduced into the circulation. Reference is made to work showing the close relation between MDF and the lysosomial hydrolases, and its biological effects on the whole animal, on isolated preparations, and in vitro. In addition to the myocardial depressant effect that has given it its name, MDF has been shown to provoke ischaemia of the splanchnic circulation and depression of the RES. The evidence on both sides is presented, including that derived from personal investigations of district haemodynamics in experimental shock. In substance, material is presented from which an objective approach can be taken to the cultural contribution of MDF in the matter of shock, its prospects, and its limitations.

[An epidemiological study of cardiac emergency cases in the province of Florence and the Southeast Florence Hospital area]

The national data provided by ANMCO in 1978 show a total of 2.5 m heart cases in Italy, including 1.5 m instances of ischaemic cardiopathy, and an annual incidence of 105,000 new cases of myocardial infarct. An assessment was made of the 1976 and 1977 pattern of "cardiological emergency cases" (ISTAT codes 402, 410-14, 427-29, 441, 450, 519, 997) in the province of Florence and two of its social and health consortia: 39 (municipalities of Dicomano, Londa, Pelago, Pontassieve, Rufina, S. Godenzo), and 51 (municipalities of Borgata Ripoli, Greve, Impruneta, S. Casciano, Tavarnelle). The records of the S. Maria Nuova, Florence Hospital were used for in-patient data, since this is the only hospital in the province with automatic filing by discharge diagnosis according to the ISTAT code. Mortality in emergency cases in the two consortia m and the province fell from 14.68% and 17.17% to 11.20% and 18.11% respectively in the two years. In both populations, the highest incidence was between 70 and 74 yr of age in 1976, and between 65 and 69 yr in 1977. In the case of infarct, mortality moved from 18.75 to 7.58% (consortia) and from 22.40% to 20.93% (province), with maximum incidences in 1976 between 70 and 74 yr (consortia and province), and in 1977 between 65 and 69 yr (province) and between 55 and 59 yr (consortia). Admissions were greatest in number on Mondays (peak hours: 11 a.m. to 4 p.m.) whereas no difference was noted between one month and another. The Hospital Resuscitation Centre, which serves the two consortia, received 45 emergency cases in 1977, including 25 infarct patients. Total mortality was 13.33% (infarct 20%). The slight numeric discrepancy between in the latter data and those held in the computer suggests that the ISTAT code may not be easy to use and not always employed by physicians in a rational manner.