British journal of anaesthesia
-
Apnoeic oxygenation can come close to matching the oxygen demands of the apnoeic patient but does not facilitate carbon dioxide (CO2) elimination, potentially resulting in dangerous hypercapnia. Numerous studies have shown that high-flow nasal oxygen administration prevents hypoxaemia, and appears to reduce the rate of increase of arterial CO2 partial pressure (PaCO2), but evidence is lacking to explain these effects. ⋯ Cardiogenic oscillations, dead space gas mixing, and micro-ventilation induced by pharyngeal pressure variations appear to be important mechanisms that combine to facilitate the clearance of CO2 during apnoea. Evolution of high-flow oxygen insufflation devices should take advantage of these insights, potentially improving apnoeic gas exchange.
-
Review Meta Analysis
Safety of 80% vs 30-35% fraction of inspired oxygen in patients undergoing surgery: a systematic review and meta-analysis.
High-inspired 80% FiO2 shows no safety compromise when compared with standard 30-35% FiO2 among surgical patients.
pearl -
Multicenter Study Observational Study
Incidence and risk factors of hypoxaemia after preoxygenation at induction of anaesthesia.
Hypoxaemia at induction is relatively common, with unsurprising independent risk factors (difficult preoxygenation, mask ventilation, and intubation).
pearl -
Effective pulmonary blood flow (COEPBF) has recently been validated for its ability to measure cardiac output (CO) in children and animals. This study compared COEPBF with the Fick method (COFick) and CO measurements using an invasive pulmonary artery flow probe (COTS). The aim of the study was to validate COEPBF against these reference methods in a porcine model of hypoxia-induced selective pulmonary hypertension. ⋯ Estimation of CO with COEPBF results in values very close to the gold standard reference methods COFick and COTS. COEPBF appears to be an accurate tool for monitoring absolute values and changes in CO during hypoxia-induced pulmonary hypertension and inhaled nitric oxide treatment.