Bag valve resuscitator versus Mapleson C circuit during manual ventilation: A bench top study.

BACKGROUND: Manual ventilation is life saving in critically ill patients. The lack of airway pressure monitoring makes it operator and device dependent. In this bench top-study, we compared a self- inflating bag valve resuscitator and a Mapleson C circuit during manual ventilation performed by critical care nurses under normal and pathologic conditions, with a special focus on delivered positive end expiratory pressure (PEEP). METHODS: Three different respiratory patterns (normal, restrictive and obstructive) were reproduced by a breathing simulator. Twenty nurses provided manual ventilation with a specific ventilatory pattern. Airway pressure, tidal volume and respiratory rate were recorded. Absolute value, error (difference between recorded and target values) and variability of PEEP were analysed. RESULTS: 3820 breathing traces were analysed. PEEP error was significantly higher with Mapelson C (43.3% vs 5.9% respectively, p < 0.001). This finding was confirmed regardless of operator skill and scenario. PEEP was more variable with Mapelson C (p < 0.05 in all scenarios). Ventilation of obstructive patients with Mapelson C resulted in higher PEEP levels compared to the reference value. Conversely, in the restrictive setting, PEEP was lower. Difference between PEEP and the minimum pressure recorded during the respiratory cycle was significantly higher with Mapelson C (p < 0.05). CONCLUSIONS: Manual ventilation with a Mapleson C circuit delivered a less accurate and less stable PEEP level compared to a self-inflating bag valve resuscitator.

Osteopontin in the Cerebrospinal Fluid of Patients with Severe Aneurysmal Subarachnoid Hemorrhage.

Aneurysmal subarachnoid hemorrhage (SAH) is associated with high morbidity and mortality. In SAH patients, plasma osteopontin (OPN) has been shown to independently predict poor outcome. The aim of the study is to investigate, in a selected population with severe SAH, OPN time course in cerebrospinal fluid (CSF) and plasma during the first week after aneurism rupture, and OPN prognostic value. We included 44 patients with the following criteria: (1) age 18 and 80 years, (2) diagnosis of SAH from cerebral aneurysm rupture, (3) insertion of external ventricular drain. Plasma and CSF were sampled at day 1, 4, and 8. OPN levels, in CSF and plasma, displayed a weak correlation on day 1 and were higher, in CSF, in all time points. Only in poor prognosis patients, OPN levels in CSF significantly increased at day 4 and day 8. Plasma OPN at day 1 and 4 was predictor of poor outcome. In conclusion, plasma and CSF OPN displays a weak correlation, on day 1. The higher levels of OPN found in the CSF compared to plasma, suggest OPN production within the CNS after SAH. Furthermore, plasma OPN, at day 1 and 4, seems to be an independent predictor of poor outcome.