Procalcitonin levels are lower in intensive care unit patients with H1N1 influenza A virus pneumonia than in those with community-acquired bacterial pneumonia. A pilot study.

PURPOSE: The purpose of the study was to know the kinetics of procalcitonin (PCT), C-reactive protein (CRP), and white blood cell (WBC) in critically ill patients with H1N1 influenza A virus pneumonia and to compare levels of these inflammatory mediators with patients with acute community-acquired bacterial pneumonia. MATERIALS AND METHODS: An observational study in a mixed intensive care unit (ICU) at a general university hospital was performed. All consecutive patients admitted to the ICU with a diagnosis of severe acute community-acquired pneumonia from September 2009 to December 2009 were included. Viral (H1N1 influenza A) and bacterial microbiological diagnoses were done in every patient. At admission, demographics, comorbidities, Simplified Acute Physiology Score, Sequential Organ Failure Assessment, Lung Injury Score, and Pao(2)/Fio(2) were recorded. At admission and after 24, 48, and 120 hours, WBC, CRP, and PCT levels were obtained. Finally, hospital and ICU length of stay and mortality were recorded. RESULTS: No differences in CRP or WBC were found between H1N1-positive patients and H1N1-negative patients (patients with acute community-acquired bacterial pneumonia). Procalcitonin levels at admission were lower in H1N1-positive patients (PCT = 0.4 [0.1-6.1] ng/mL) than in the H1N1-negative patients (24.8 [13.1-34.5] ng/mL). Procalcitonin significantly decreased with time but remained lower in the H1N1-positive group at all measurements (P < .05 for all comparisons). CONCLUSIONS: Among patients admitted to the ICU with pneumonia, the PCT level could help identify H1N1 influenza A virus pneumonia and thus enable earlier antiviral therapy.

Maximum FIO2 in minimum time depending on the kind of resuscitation bag and oxygen flow.

OBJECTIVE: To analyze what FIO2 can be reached, and how long it takes using the different autoinflated resuscitation bags and increasing oxygen flows. DESIGN: Experimental analysis on the effect of three different models of autoinflated resuscitation bag and increasing oxygen flows in the final FIO2, and time spent to reach it. SETTING: Laboratory, with a gas analyzer and a lung simulator to measure inspired FIO2. INTERVENTIONS: Simulated cardiopulmonary resuscitation. Three different autoinflated resuscitation bags were studied; A, the classic one with oxygen delivery directly into the bag, without reservoir, B, a new one without the reservoir device; and C, a new one with the reservoir device properly implemented. Increasing oxygen flows were administered until FIO2 stabilized. RESULTS: With model A the maximum FIO2 reached was 0.73 in 70 s using a 20 l/min oxygen flow. With model B the maximum FIO2 reached was 0.65 in 90 s using a 20 l/min oxygen flow. The best FIO2 (0.99) was reached using model C in 55 s with 12 l/min oxygen flow. In the three models a high correlation between oxygen flow and FIO2 was found (r>0.8). CONCLUSIONS: It is mandatory to use model C resuscitation autoinflated bag with 12 l/min of oxygen flow during the resuscitation maneuvers. Using another autoinflated bag model, maximum oxygen flows (i.e., 20 l/min) are needed. The resuscitation autoinflated bags showed less effectiveness when they were not properly assembled.