Early Rapid Fluid Therapy Is Associated with Increased Rate of Noninvasive Positive-Pressure Ventilation in Hemoconcentrated Patients with Severe Acute Pancreatitis

BACKGROUND/AIMS

Hematocrit is a widely used biomarker to guide early fluid therapy for patients with acute pancreatitis (AP), but there is controversy over whether early rapid fluid therapy (ERFT) should be used in hemoconcentrated patients. This study investigated the association of hematocrit and ERFT with clinical outcomes of patients with AP.

METHODS

Data from prospectively maintained AP database and retrospectively collected fluid management details were stratified according to actual severity defined by revised Atlanta classification. Hemoconcentration and "early" were defined as hematocrit > 44% and the first 6 h of general ward admission, respectively, and "rapid" fluid rate was defined as ≥ 3 ml/kg/h. Patients were allocated into 4 groups for comparisons: group A, hematocrit ≤ 44% and fluid rate < 3 ml/kg/h; group B, hematocrit ≤ 44% and fluid rate ≥ 3 ml/kg/h; group C, hematocrit > 44% and fluid rate < 3 ml/kg/h; and group D, hematocrit > 44% and fluid rate ≥ 3 ml/kg/h. Primary outcome was rate of noninvasive positive-pressure ventilation (NPPV).

RESULTS

A total of 912 consecutive AP patients were analyzed. ERFT has no impact on clinical outcomes of hemoconcentrated, non-severe or all non-hemoconcentrated AP patients. In hemoconcentrated patients with severe AP (SAP), ERFT was accompanied with increased risk of NPPV (odds ratio 5.96, 95% CI 1.57-22.6). Multivariate regression analyses confirmed ERFT and hemoconcentration were significantly and independently associated with persistent organ failure and mortality in patients with SAP.

CONCLUSIONS

ERFT is associated with increased rate of NPPV in hemoconcentrated patients with SAP.

Effect of Jet Nebulization on Noninvasive Positive-Pressure Ventilation Administered with Noninvasive or Intensive Care Unit Ventilators: A Bench Study

BACKGROUND

Most of the patients on noninvasive positive pressure ventilation require aerosol inhalation therapy to moisturize the airways or deliver drugs in acute settings. However, the effect of jet nebulization on noninvasive positive pressure ventilation (NPPV) has not been determined.

OBJECTIVES

This study was designed to investigate the impact of jet nebulization on NPPV applied in ventilators.

METHODS

Aerosol therapy during NPPV was conducted in a simulated lung. The jet nebulizer was connected at both the distal and proximal end of the exhalation valve for the noninvasive ventilators, while it was placed both in front of the Y tube proximal to the patient and at 15 cm distance from the Y-tube inspiratory limb distal to the patient for the intensive care unit (ICU) ventilators. Driving flow was set at 4 and 8 L/min, respectively.

RESULTS

TPmin (time from the beginning of the lung simulator's inspiratory effort to the lowest value of airway pressure needed to trigger the ventilator), Ttrig (time to trigger), and Ptrig (the magnitude of airway pressure drop needed to trigger) were not significantly altered by jet nebulization in the noninvasive ventilators, while they were significantly increased in the ICU ventilators. The greater the driving flow, the stronger the impact on TPmin, Ttrig, and Ptrig. The actual tidal volume and control performance were not significantly affected by jet nebulization in either noninvasive or ICU ventilators. The tidal volume monitored was significantly increased at 8 L/min driving flow. The greater the driving flow, the stronger the impact on the tidal volume monitored.

CONCLUSION

The effect of jet nebulization on NPPV was different when compared to invasive ventilation. Jet nebulization only affected the tidal volume monitored in the noninvasive ventilator. Jet nebulization also affected the triggering performance and tidal volume monitored in the ICU ventilator.

Noninvasive mechanical ventilation in chronic obstructive pulmonary disease and in acute cardiogenic pulmonary edema

Noninvasive ventilation (NIV) with conventional therapy improves the outcome of patients with acute respiratory failure due to hypercapnic decompensation of chronic obstructive pulmonary disease (COPD) or acute cardiogenic pulmonary edema (ACPE). This review summarizes the main effects of NIV in these pathologies. In COPD, NIV improves gas exchange and symptoms, reducing the need for endotracheal intubation, hospital mortality and hospital stay compared with conventional oxygen therapy. NIV may also avoid reintubation and may decrease the length of invasive mechanical ventilation. In ACPE, NIV accelerates the remission of symptoms and the normalization of blood gas parameters, reduces the need for endotracheal intubation, and is associated with a trend towards lesser mortality, without increasing the incidence of myocardial infarction. The ventilation modality used in ACPE does not affect the patient prognosis.