[Argentine consensus of non-invasive ventilation]. / Consenso argentino de ventilación no invasiva.

Non-invasive ventilation (NIV) is nowadays increasingly used. The significant decrease in tracheal intubation related complications makes it particularly attractive in patients with moderately acute respiratory failure (ARF) who still have some degree of respiratory autonomy. It has also been used to support patients with chronic respiratory failure. However, final outcomes are variable according to the conditions which determined its application. This Consensus was performed in order to review the evidence supporting the use of positive pressure NIV. The patho-physiological background of NIV and the equipment required technology are described. Available evidence clearly suggests benefits of NIV in acute exacerbation of chronic obstructive pulmonary disease (COPD) and in cardiogenic pulmonary edema (Recommendation A). When considering ARF in the setting of acute respiratory distress syndrome results are uncertain, unless dealing with immunosupressed patients (Recommendation B). Positive results are also shown in weaning of mechanical ventilation (MV), particularly regarding acute exacerbation of COPD patients (Recommendation A). An improved quality of life in chronic respiratory failure and a longer survival in restrictive disorders has also been shown (Recommendation B) while its benefit in stable COPD patients is still controversial (Recommendation C). NIV should be performed according to pre-established standards. A revision of NIV related complications is performed and the cost-benefit comparison with invasive MV is also considered.

Assessment of bronchodilator response through changes in lung volumes in chronic airflow obstruction.

Although FEV1 improvement is routinely used to define bronchodilator (BD) response, it correlates poorly with clinical effects. Changes in lung volumes (LV) have shown better correlation with exercise tolerance and might be more sensitive to detect BD effects. We assessed the additional contribution of measuring LV before and after BD to detect acute improvement in lung function not demonstrated by FEV1, and the influence of the response criteria selected on this contribution. We analyzed 98 spirometries and plethismographies performed pre and post BD in patients with airflow obstruction (FEV1/FVC < 70%). BD response was defined for FEV1 and FVC as per ATS guidelines and for other LV as delta > or = 10% of baseline (delta > or = 5 and > or = 15% were also analyzed). FEV1 identified as responders 32% of patients. Greater proportions were uncovered by slow vital capacity (51%, p < 0.001), inspiratory capacity (43%, p < 0.05) and residual volume (54%, p < 0.001). Slow spirometry identified 11% of responders additional to those detected by FEV1 and FVC. Plethismography added 9% more. The magnitude of volume responses correlated with the degree of baseline hyperinflation. Percentages of responders varied greatly using different thresholds (delta > or = 5 and > or = 15%). Mean change and proportions of responders for each LV varied significantly (p < 0.05) whether change was expressed as percent of baseline or predicted values. A considerable proportion of patients with airflow obstruction shows acute response to bronchodilators identified by changes in lung volumes but not detected by an improvement in FEV1. The selection of LV response criteria has important influence on the magnitude of this additional detection.

Octreotide enhances portal pressure reduction induced by propranolol in cirrhosis: a randomized, controlled trial.

BACKGROUND: In vitro, octreotide potentiates vasoconstriction in isolated, preconstricted, mesenteric arterial vessels. In cirrhotic patients, portal pressure (HVPG) reduction induced by propranolol is partly due to splanchnic vasoconstriction. AIM: To evaluate HVPG effects of octreotide administration in cirrhotic patients receiving long-term propranolol. PATIENTS AND METHODS: A randomized, controlled trial. First study: a total of 28 patients were studied at baseline and 30 and 60 minutes after octreotide (200 mug) (N = 14) or placebo (N = 14) and then treated with propranolol for approximately 30 days (106 +/- 5 mg/day). Second study: after baseline evaluation patients received octreotide or placebo as they were assigned to in the first study and measurements repeated 30 and 60 minutes later. RESULTS: In the first study baseline HVPG was 18.7 +/- 0.9 mmHg and decreased to 17.1 +/- 1.1 mmHg and 17.1 +/- 1.0 mmHg (both P < 0.05 vs baseline) at 30 and 60 minutes after octreotide, respectively. Eight patients decreased their HVPG after octreotide. In the second study baseline HVPG was 15.6 +/- 1.3 mmHg (P < 0.01 vs baseline HVPG in first study) and decreased to 14.1 +/- 1.2 mmHg and 14.1 +/- 1.3 mmHg (25.7 +/- 5% lower than baseline HVPG in the first study, P < 0.01) (both P < 0.05 vs baseline) at 30 and 60 minutes after octreotide, respectively. Nine patients (2 responders/7 nonresponders to propranolol) decreased their HVPG after octreotide. Octreotide effects may be mediated by potentiation and additive mechanisms. CONCLUSIONS: Octreotide enhances HVPG reduction induced by propranolol in cirrhotic patients.

Assessment of bronchodilator response through changes in lung volumes in chronic airflow obstruction

Although FEV, improvement is routinely used to define bronchodilator (BD) response, it correlates poorly with clinical effects. Changes in lung volumes (LV) have shown better correlation with exercise tolerance and might be more sensitive to detect BD effects. We assessed the additional contribution of measuring LV before and after BD to detect acute improvement in lung function not demonstrated by FEV, and the influence of the response criteria selected on this contribution. We analyzed 98 spirometries and plethismographies performed pre and post BD in patients with airflow obstruction (FEV,/FVC < 70%). BD response was defined for FEV, and FVC as per ATS guidelines and for other LV as o>_10% of baseline (4>_5 and >_15% were also analyzed). FEV, identified as responders 32% of patients. Greater proportions were uncovered by slow vital capacity (51 %, p<0.001), inspiratory capacity (43%, p<0.05) and residual volume (54%, p<0.001). Slow spirometry identified 11% of responders additional to those detected by FEV, and FVC. Plethismography added 9% more. The magnitude of volume responses correlated with the degree of baseline yperinflation. Percentages of responders varied greatly using different thresholds (A>5 and >_15%). Mean change and proportions of responders for each LV varied significantly (p<0.05) whether change was expressed as percent of baseline or predicted values. A considerable proportion of patients with airflow obstruction shows acute response to bronchodilato rs identified by changes in lung volumes but not detected by an improvement in FEV, The selection of LV response criteria has important influence on the magnitude of this additional detectìon.