For example: char a; a= getchar(); The function getchar() reads a single character from the standard input device, the keyboard being assumed because that is the standard input device, and assigns it to the variable a.
This excludes acute and chronic respiratory failure (518.84), acute respiratory distress (518.82), acute respiratory failure following trauma and surgery (518.51), chronic respiratory failure (518.83), respiratory arrest (799.1), and respiratory failure, newborn (770.84). This applies to respiratory failure NOS.
Respiratory failure can be acute (develops within minutes or hours in patients with no or minor evidence of pre-existing respiratory disease), acute on chronic (an acute deterioration in an individual with pre-existing respiratory failure) or chronic (develops over several days or longer in patients with existing respiratory disease).