Monica Delmastro

Changes in the practice of non-invasive ventilation in treating COPD patients over 8 years

Objective. We reviewed data of 208 episodes of acute respiratory failure due to chronic obstructive pulmonary disease treated by non-invasive ventilation (NIV) in our Respiratory Intensive Care Unit (RICU) from its opening in 1992 to 1999.Material and methods. We assessed whether the rate of NIV success, the severity of the disease, and the associated costs changed in this period during which the staff and the equipment did not change.Results. The failure rate was constant over the years (17.2% on average). The severity of the episodes of ARF, defined by pH and APACHE II at admission, worsened during the years. The statistical change point test allowed us to identify 1997 as the year of a significant change in the severity of admission pH and therefore to identify two different periods: 1992–1996 (mean pH = 7.25±0.07) and 1997–1999 (7.20±0.08; P<0.001). In this latter period the risk of failure for a patient with a pH <7.25 was threefold lower than in 1992–1996. In 1997–1999 an increasing number of episodes of ARF with a pH >7.28 were treated in the Medical Ward (20% vs 60%). This allowed a significant reduction of daily cost per patient treated with NIV (558±8 Euros vs 470±14 Euros, respectively; P<0.01).Conclusions. We conclude that, over time, experience with NIV may progressively allow more severely ill patients to be treated without changing the rate of success. The daily cost of NIV per patient can be reduced by treating less severely ill patients outside the RICU.

Noninvasive mechanical ventilation as a palliative treatment of acute respiratory failure in patients with end-stage solid cancer

Noninvasive ventilation (NIV) is widely used in the treatment of acute respiratory failure (ARF), but not in patients with end-stage solid cancer in whom any form of mechanical ventilation tends to be avoided. In a prospective study, we investigated the use of NIV in 23 patients with solid malignancies receiving palliative care and who were affected by severe hypoxic or hypercapnic ARF. The most frequent causes of ARF were exacerbations of preexisting pulmonary diseases and pneumonia. After one hour, NIV significantly improved PaO2/FiO2 (from 154±48 to 187±55) and the Borg dyspnoea score (from 5.59±1.2 to 2.3±0.3). NIV also improved pH, but only in the subset of hypercapnic patients. Thirteen of 23 (57%) patients were successfully ventilated and discharged alive, while 10/23 patients (43%) met the criteria for intubation or died after an initial trial of NIV. Only two of these patients accepted invasive ventilation. The mortality rate in this subgroup was 9/10 (90%). A higher Simplified Acute Physiology Score (SAPS II) and a lower PaO2/FiO2 on admission were associated with a lower probability of survival. Patients with ARF and end-stage solid malignancies have an overall ICU and 1-year mortality rate of 39% and 87%, respectively, but despite this, a consistent subset of patients may still be successfully treated with NIV, if the cause of ARF is reversible.

Respiratory changes during defecation in patients with chronic respiratory failure

Oxygen (O2) desaturation may occur in patients affected by respiratory diseases during daily activities, although most of these activities, e.g. walking, washing and cooking, can be avoided or eventually performed with an external aid. In this prospective study, the respiratory changes induced by the mandatory effort of defecation were assessed in patients with chronic respiratory insufficiency. Twenty-four consecutive patients with chronic respiratory failure due to obstructive or restrictive pulmonary disorders, showing a marked O2 desaturation during the 6-min walk test, were enrolled. Thirteen of them were already established on long-term O2 therapy (LTOT), while 11 were not. O2 saturation (Sa,O2), respiratory rate (RR), cardiac frequency (fc) and dyspnoea were measured at rest, and during and after defecation. Sa,O2 decreased significantly during defecation, while RR, fc and dyspnoea increased, both in the subgroup of patients without significant resting hypoxaemia and in the subgroup of patients receiving their usual resting flow of LTOT, as compared to resting values. In conclusion, the respiratory system of patients with chronic respiratory failure may be significantly strained by defecation.

Tracheostomy and related host–patogen interaction are associated with airway inflammation as characterized by tracheal aspirate analysis

In the last years an increasing number of subjects experienced respiratory failure and underwent tracheostomy. The aim of the present study was to analyze tracheal aspirates from the inflammatory point of view. Samples were collected from 38 consecutive tracheostomized patients: 13 COPD, 6 with neurologic disorders and 19 with other different causes of respiratory failure. We analyzed cells and soluble mediators related to inflammation and/or infection. We also compared results obtained in the tracheal aspirate of COPD patients with the same determination in the sputum of another group of non-tracheostomized COPD patients (n=41). Regardless of the underlying diagnosis, most of the samples were Pseudomonas aeruginosa positive and cells and soluble mediator did not differ. Treatment with steroids was associated with lower amount of total cells, neutrophils and lymphocytes, whereas treatment with antibiotics was not. Tracheal aspirate neutrophils correlated with PaCO(2) values; neutrophils and eosinophils correlated with their percentages in blood. As compared with sputa obtained from another group of culture-positive non-tracheostomized COPDs, tracheal aspirates showed similar cell count, proportions of inflammatory cells, and infection/inflammatory mediators. In conclusion tracheal aspirates presented high amounts of viable cells and soluble mediators independently to the cause of respiratory failure leading to tracheotomy and they represent suitable specimens to study infection/inflammation interactions.

MVarallo: a new M(Like) alpha 1-antitrypsin-deficient allele

A 73-year-old never-smoker woman with chronic bronchitis, increasing dyspnoea, and airflow limitation with a FEV1 of 49% of predicted value had low serum level of alpha-1-antitrypsin (69 mg/dL, normal range 150–350). Isoelectric focusing showed an Mlike pattern. Direct sequencing showed, in the second exon, a particular DNA alteration localized between codon 41 and codon 51: a region of 30 base pairs (bp) was completely deleted and substituted by a 22-bp sequence. The resulting loss of 8 bp yields, in the second exon, a 70–71 stop codon. This new Mlike variant was denominated MVarallo from the site where it was discovered.