Drivers and impact of antifungal therapy in critically ill patients with Aspergillus-positive respiratory tract cultures.

Invasive pulmonary aspergillosis (IPA) is an increasingly recognised problem in critically ill patients. Little is known about how intensivists react to an Aspergillus-positive respiratory sample or the efficacy of antifungal therapy (AFT). This study aimed to identify drivers of AFT prescription and diagnostic workup in patients with Aspergillus isolation in respiratory specimens as well as the impact of AFT in these patients. ICU patients with an Aspergillus-positive respiratory sample from the database of a previous observational, multicentre study were analysed. Cases were classified as proven/putative IPA or Aspergillus colonisation. Demographic, microbiological, diagnostic and therapeutic data were collected. Outcome was recorded 12 weeks after Aspergillus isolation. Patients with putative/proven IPA were more likely to receive AFT than colonised patients (78.7% vs. 25.5%; P <0.001). Patients with host factors for invasive fungal disease were more likely to receive AFT (72.5% vs. 37.4%) as were those with multiorgan failure (SOFA score >7) (68.4% vs. 36.9%) (both P <0.001). Once adjusted for disease severity, initiation of AFT did not alter the odds of survival (HR = 1.40, 95% CI 0.89-2.21). Likewise, treatment within 48 h following diagnosis did not change the clinical outcome (75.7% vs. 61.4%; P = 0.63). Treatment decisions appear to be based on diagnostic criteria and underlying disease severity at the time of Aspergillus isolation. IPA in this population has a dire prognosis and AFT is not associated with reduced mortality. This may be explained by delayed diagnosis and an often inevitable death due to advanced multiorgan failure.

Nitric oxide and prostacyclin as test agents of vasoreactivity in severe precapillary pulmonary hypertension: predictive ability and consequences on haemodynamics and gas exchange.

BACKGROUND: In patients with primary pulmonary hypertension who respond to vasodilators acutely, survival can be improved by the long term use of calcium channel blockers. However, testing for such a response with calcium channel blockers or prostacyclin (PGI2) may cause hypotension and adversely affect gas exchange. Nitric oxide (NO), which does not have these effects, could be a better test agent. METHODS: NO (10, 20, and 40 ppm for 15 minutes), PGI2 (1-->10 ng/kg/min), and oral nifedipine (10 mg, then 20 mg/h) were administered sequentially to 10 patients after determination of the 24 hour spontaneous variability of their pulmonary and systemic mean arterial pressures. Patients were considered responders if the mean pulmonary artery pressure or pulmonary vascular resistance decreased by 20% or more. RESULTS: Six patients (60%) responded to all three agents, and three to none of the agents. One patient responded to PGI2 only. In those who responded to vasodilators, NO had no major effect on gas exchange or systemic haemodynamics, while PGI2 and nifedipine both induced systemic hypotension (mean (SD) systemic arterial pressure 72 (14) versus 89 (19) mm Hg with PGI2 and 72 (15) versus 86 (17) mm Hg with nifedipine, p < 0.05) and hypoxaemia (PaO2 8.7 (1.4) versus 10.8 (1.0) kPa with PGI2 and 8.6 (1.4) versus 10.2 (1.5) kPa with nifedipine, p < 0.05) and increased venous admixture (28 (9) versus 14 (4)% with PGI2 and 22 (9) versus 13 (5)% with nifedipine, p < 0.05). CONCLUSIONS: NO inhalation can accurately predict a vasodilator response to nifedipine in patients with severe pulmonary hypertension without adverse effects on systemic haemodynamics and gas exchange. This absence of side effects may make it a more appropriate agent for testing the vasodilator response.