The quality of nursing appears to be a measurable and critical factor in the weaning from mechanical ventilation of patients with chronic obstructive pulmonary disease. Below a threshold in the available workforce of ICU nurses, the weaning duration of patients with chronic obstructive pulmonary disease increases dramatically. Therefore, very close attention should be given to the education and number of ICU nurses.

These data indicate that acute hypercapnia increases DO2 and O2 off-loading capacity in ARDS patients with normal plasma lactate, without increasing O2 extraction. Whether this would be beneficial in patients with elevated lactate levels, indicating tissue hypoxia, remains to be determined. Furthermore, even though hypercapnia was well tolerated, the increase in Qva/Qt, CI, and MPAP should prompt caution in patients with severe hypoxemia, as well as in those with depressed cardiac function and/or severe pulmonary hypertension.

Two patients admitted to two different medical wards of our institution following respiratory decompensation of chronic obstructive pulmonary disease (COPD) were subsequently transferred to the same room of the medical intensive care unit (ICU) and intubated. Both patients developed invasive pulmonary aspergillosis and died soon after. Because COPD itself is rarely associated with lethal pulmonary aspergillosis, both cases were reviewed, and a retrospective investigation was conducted. Both patients had repeated sputum cultures while on the medical ward before their admission to the ICU; none of the sample grew Aspergillus spp. A. fumigatus was found in tracheal aspirates of both patients from the first day of their intubation while in the ICU. The pulmonary condition of both patients worsened, and invasive aspergillosis was diagnosed by bronchoalveolar lavage. Despite therapy with amphotericin B, the patients died 16 and 22 d after intubation, respectively. Both deaths were attributed to pulmonary aspergillosis; autopsy confirmed a massive pneumonia of the five lobes due to A. fumigatus in one patient. Investigation revealed that an air filter had been replaced 30 h before the first patient was admitted to the room. Experimental air filter replacement performed 12 d after the second patient died revealed the presence of A. fumigatus on the surface of the filters as well as a 10-fold increase in room air fungal counts during the procedure. This study shows that exposure to high concentrations of airborne Aspergillus spp. related to air filter change was associated with fatal invasive aspergillosis in two mechanically ventilated patients. Such infection can be prevented by the establishment and application of guidelines for air filter replacement.

Abstractmay make it a more appropriate agent for testing the vasodilator response. Background -In patients with primary (Thorax 1997;52:369-372) pulmonary hypertension who respond to vasodilators acutely, survival can be im- Keywords: pulmonary hypertension, vasodilators, nitric proved by the long term use of calcium oxide, prostacyclin, calcium channel blockers. channel blockers. However, testing for such a response with calcium channel blockers or prostacyclin (PGI 2 ) may causeIn patients with primary pulmonary hyperhypotension and adversely affect gas extension an improvement in survival can be change. Nitric oxide (NO), which does not obtained by the long term administration of have these effects, could be a better test calcium channel blockers to those who respond agent.to vasodilators given acutely. 1 Calcium channel Methods -NO (10, 20, and 40 ppm for blockers have been used for this test procedure, 15 minutes), PGI 2 (1->10 ng/kg/min), and but their effect on systemic haemodynamics can oral nifedipine (10 mg, then 20 mg/h) were induce severe or even life threatening effects. 2 administered sequentially to 10 patients Because of its short half life and pulmonary after determination of the 24 hour spon-vasodilator effect, prostacyclin (PGI 2 ) has been taneous variability of their pulmonary and administered instead and is regarded as the systemic mean arterial pressures. Patients screening agent of choice.3 However, PGI 2 is were considered responders if the mean an equally potent systemic vasodilator and may pulmonary artery pressure or pulmonary impair pulmonary hypoxic vasoconstriction vascular resistance decreased by 20% or with resulting hypoxaemia. Recent studies have more.suggested that nitric oxide (NO), a selective Results -Six patients (60%) responded to pulmonary vasodilator, may be a better screenall three agents, and three to none of the ing agent.4 5 The purpose of the present study agents. One patient responded to PGI 2 was to evaluate the ability of NO to predict a only. In those who responded to vaso-response to calcium channel blockers, and to Medical ICU Division dilators, NO had no major effect on gas compare its effects on haemodynamics and gas venous blood samples were collected sim-ues of PAPspont for the responders were compared with those of the decrease in mean ultaneously for blood gas determinations. Derived variables were computed according to PAP obtained with each vasodilator using a Wilcoxon signed rank test. standard equations.Since a previous study from our ICU demonstrated a 24 hour variability of 11% in mean PAP and 14% in pulmonary vascular resistance ResultsAll results are expressed as mean (SD). Ten (PVR) in patients with pulmonary hypertension, in the absence of any drug ad-patients were studied, four of whom had primary pulmonary hypertension while in the others ministration, 7 these parameters were first recorded every hour for 24 hours without any pulmonary hypertension was associated with cirrhosis and portal hypertension (2), conpharmacological intervent...

Background -Bronchoalveolar lavage is considered a safe procedure. When performed in the mechanically ventilated patient, however, potentially harmful effects