The relationship between extravascular lung water and oxygenation in three patients with influenza A (H1N1)-induced respiratory failure

Abstract

This case series reports the correlation between extravascular lung water (EVLW) and the partial arterial oxygen pressure/fractional inspiratory oxygen (PaO(2)/FiO(2)) ratio in three patients with severe influenza A (H1N1)-induced respiratory failure. All patients suffered from grave hypoxia (PaO(2), 26-42 mmHg) and were mechanically ventilated using biphasic airway pressure (PEEP, 12-15 mmHg; FiO(2), 0.8-1) in combination with prone positioning at 12 hourly intervals. All patients were monitored using the PICCO system for 8-11 days. During mechanical ventilation, a total of 62 simultaneous determinations of the PaO(2)/FiO(2) ratio and EVLW were performed. A significant correlation between EVLW and the PaO(2)/FiO(2) ratio (Spearman-rho correlation coefficient, -0.852; p < 0.001) was observed. In all patients, a decrease in EVLW was accompanied by an improvement in oxygenation. Serum lactate dehydrogenase levels were elevated in all patients and significantly correlated with EVLW during the intensive care unit stay (Spearman-rho correlation coefficient, 0.786; p < 0.001). In conclusion, EVLW seems increased in patients with severe H1N1-induced respiratory failure and appears to be closely correlated with impairments of oxygenatory function.

Effect of Repeated Recruitment Manoeuvres on Patients with Severe Acute Respiratory Distress Syndrome

“…The severity of pulmonary oedema can be directly reflected by EVLW through PiCCO monitoring. Extravascular lung water index is the most specific quantitative index for monitoring pulmonary oedema (12) and is closely related to the prognosis of critically ill patients (13). Chew et al (14) studied a prospective, observational cohort of 51 patients with shock and found that EVLW is associated with the degree of lung injury and mortality.…”

Fetal hemodynamic changes in pregnant women with influenza AH1N1 infection and reduced arterial partial pressure of oxygen

“…Influenza AH1N1 infection increases alveolar secretion and produces a local and systemic inflammatory response and an increase in extravascular lung water 3 . The ratio between P a O 2 and the fraction of inspired oxygen (FiO 2 ) can be altered, leading to ARDS.…”