IPPV is invasive and non-physiological, and hence reserved for cases where non-invasive ventilation is not suitable.

Terminology

PEEP: positive end expiratory pressure
Cycling: change from inspiration to expiration or the reverse. It can be volume cycled, pessure cycled, time cycled or flow cycled.
Modes of ventilation: controlled mode, assist controlled mode, assist mode
Controlled mode – every breath by the ventilator; even if the subject wants breath spontaneously, it is not permitted. Volume and pressure controlled modes are available.
Assist control mode – IMV and SIMV (synchronized intermittent mandatory ventilation). SIMV removes the chance of fighting …

Checking for airway patency may be life saving in certain situations which may be mistaken for other conditions like an acute coronary syndrome. Usual cause of airway obstruction in an uncoscious patient is falling back of the tongue. Head tilt and chin lift / jaw thrus will help in this situation. But head tilt should not be used in trauma.
If the oropharyngeal reflexes are not adequate, an oropharyngeal airway is useful. If oropharyngeal airway is not suitable, a nasopharyngeal airway can be used. Advanced airways are considered if even this …

Oxygen therapy can be normobaric or hyyperbaric. During oxygen therapy, ventilation and airway maintenance should be adequate so that oxygen reaches the lung for gas exchange. Reserve of oxygen in the body is 1.5 litres, which lasts for about 6 minutes in circulatory arrest assuming a consumption of 250 ml/min. Hb contains 800 ml and alveoli contains about 400 ml of oxygen. Pre-oxygenation prior to induction of anaesthesia leads to denitration and increase in the alveolar oxygen content, enabling tolerance of longer period of apnea.
Circulatory gradient of oxygen: Oxygen …

Oxygen pressure guage attached to a Boyle’s machine for general anaesthesia.

Nitrous oxide pressure guage attached to a Boyle’s machine for general anaesthesia.

Isoflurane delivery device attached to a Boyle’s machine used for general anaesthesia using inhalational agents.

Halothane delivery device used for delivering metered dose of halothane for general anaesthesia. The device can be attached on the Boyle’s machine and halothane vapour delivered along with oxygen through the endotracheal tube. Halothane is an inhalational anaesthetic agent like nitrous oxide and isoflurane.

Boyle’s machine used for delivering oxygen and anaesthetic gases for general anaesthesia. Flow meters for nitrous oxide and oxygen as well as delivery device for isoflurane are seen attached to the top bar. Pressure guages for nitrous oxide with blue screens are seen on the left side and those for oxygen with white screens are seen on the right side.

Nitrous oxide and oxygen flow meters as part of a Boyle’s apparatus used for anaesthesia. The position of the float in the graduated tubing goes up as the flow increases.