Why are some patients who meet the definition for respiratory failure not intubated and mechanically ventilated to normalize their blood gases?
Children tolerate hypercarbia better than adults do. If oxygenation is adequate and hypercarbia is likely to be reversed in the near future, some intensivists permit the hypercarbia to persist for a period of time. So-called permissive hypercarbia reduces barotrauma to the lungs that results from positive-pressure and mechanical ventilation. In patients with reactive airway disease or asthma, positive-pressure ventilation is fraught with risk of pneumomediastinum and pneumothorax. Because there are effective medications to reverse airway obstruction in a relatively short period of time, some patients can be closely monitored without endotracheal intubation and mechanical ventilation, despite levels of CO 2 that define respiratory failure.