Positive end-expiratory pressure lung recruitment: comparison between lower inflection point and ultrasound assessment.

BACKGROUND: Maintenance of the open lung alveoli in the expiration on mechanical ventilation in acute lung injury/acute respiratory distress syndrome (ALI/ARDS) remains challenging despite advances in lung imaging. The inspiratory lower inflection point (LIP) on the ventilator pressure-volume (P-V) curve estimates the required end-expiratory pressure for recruitment of alveolar consolidation. Alternatively, the end-expiratory pressure for recruitment of crater-like subpleural alveolar consolidation could be simply followed with ultrasound. These two methods for setting the ventilators positive end-expiratory pressure (PEEP) were compared. METHODS: The observational study in surgical/neurosurgical intensive care between October 2009 and November 2011 included 17 deeply sedated or relaxed patients. LIP was measured with continuous low-flow method, as a pressure in cmH(2)O. Expiratory levelling between lower border of subpleural consolidation and adjacent pleural line, which means lung recruitment, was followed with linear ultrasound probe. PEEP in cmH(2)O at which the levelling occurs was compared with LIP pressure. RESULTS: LIP pressure never exceeds the PEEP for recruitment of subpleural consolidations followed with ultrasound. A significant correlation (r = 0.839; p < 0.05) was found between two methods. CONCLUSIONS: In this study, positive end-expiratory pressures for recruitment of subpleural consolidations followed by ultrasound always exceed the pressures measured with LIP. Respecting this, ultrasound method could be the guide for PEEP lung recruitment.

[Croatian Society for Haematology and Transfusion Medicine Guidelines on the diagnosis and management of heparin induced thrombocytopenia (HIT)]. / Smjernice Hrvatskog drustva za hematologiju i transfuzijsku medicinu u dijagnosticko-terapijskom postupku za trombocitopeniju izazvanu heparinom (HIT).

Heparin induced thrombocytopenia (HIT) is a serious complication of heparin administration. In the last decade, this clinical syndrome has come into the focus of interest, primarily because of the severe thromboembolic complications that may lead to lethal outcome. In addition, great improvements have been made in the treatment with direct thrombin inhibitors and in laboratory diagnosis of HIT. As guidelines for diagnostic and management of HIT upgrade the quality of patient treatment, activities for their development have been launched in the Republic of Croatia. Based on British Committee for Standards in Haematology (BCSH) recommendations on diagnostic and treatment of HIT from 2006, activities for the introduction of new assays for anti-heparin antibodies were launched in 2008 and 2009, including algorithm of laboratory testing for HIT, sheet for clinical assessment of HIT (4T score), and education oftransfusiologists and clinicians. Upon evaluation of the results collected during one-year period, the Croatian Society of Haematology and Transfusion Medicine nominated a task force for the development of guidelines for HIT in January 2010. Following wide-ranging discussion, the guidelines were adopted in May 2011.

Ultrasonographic finding of lung sliding in patients on mechanical ventilation with alveolar-interstitial syndrome.

BACKGROUND AND OBJECTIVES: To determine the visibility of pleural lung sliding in alveolar-interstitial syndrome (AIS) in patients on mechanical ventilation at two different time points, as a confirmatory ultrasonographic method for excluding pneumothorax. METHODS: Fifty-two mechanically ventilated patients in the semirecumbent position in a surgical/neurosurgical intensive care unit with ultrasonographic lung 'comet tails' in three upper anterolateral intercostal spaces, indicating the presence of AIS, were scanned for lung sliding in the same three intercostal spaces with a linear 5-10 MHz transducer after starting mechanical ventilation and on weaning trials. Pneumothorax and atelectasis were excluded by chest radiograph. RESULTS: Absent lung sliding was found in 22.7% of intercostal spaces scanned after starting mechanical ventilation and in 21.2% of scans taken on weaning trials. The lowest invisible rate was in patients with acute heart failure and the highest in patients with acute respiratory distress syndrome. CONCLUSION: Lung sliding specificity in AIS during mechanical ventilation was 78%. Our opinion is that different levels of airway pressure between starting mechanical ventilation and weaning trials have no influence on lung sliding visibility.

Human soluble TREM-1: lung and serum levels in patients with bacterial ventilator associated pneumonia.

Human soluble triggering receptor expressed on myeloid cells (sTREM-1) is a glycoprotein of the immunoglobulin superfamily. In normal lung tissue, sTREM-1 is selectively expressed in lung alveolar macrophages specialized for pathogen clearance and is up-regulated in the presence of bacteria and fungi. The aim of this study was to assess sTREM-1 levels in serum and lungs of patients with ventilator associated pneumonia (VAP) and to evaluate its potential diagnostic role. The study cohort included 31 patients meeting the criteria for VAP, including clinical, microbiological, radiological and laboratory findings in patients on mechanical ventilation for more than 48 hours and with Clinical Pulmonary Infection Score (CPIS) > 6. Serum and lung levels of sTREM-1 were obtained and tested for differences. The samples were analyzed using ELISA technique and the values were expressed in pg/mL. The samples for lung sTREM-1 were obtained from direct bronchial lavage fluid and serum samples from peripheral blood. Differences were tested by Mann Whitney U test with P < 0.05 considered significant. In patients with bacterial VAP, a statistically significant difference was found between serum and lung sTREM-1 levels (P < 0.05), with very high levels of sTREM-1 recorded in lung samples (mean value 1565 pg/mL). There was no statistically significant difference in pulmonary sTREM-1 level between the polymicrobial and monomicrobial VAP groups. In conclusion, sTREM-1 is present in a high concentration in the lungs of patients with bacterial VAP. sTREM-1 levels can help in making the diagnosis of bacterial pneumonia as a standalone marker.

Constant cardiac output monitoring using the PiCCO and LiDCO methods versus PAK in septic patients: when to do calibration?

The accuracy of cardiac output measurement by two most widely used methods of less invasive hemodynamic monitoring and by the standard technique of thermodilution with pulmonary catheter was assessed. The measurements were carried out in septic surgical patients immediately after and between system calibrations. Study results showed satisfactory compatibility of measurements performed by the two methods and by pulmonary catheter in both phases, thus system calibration being recommendable in hemodynamically unstable septic patients.