Insufflation () is the act of blowing something (such as a gas, powder, or vapor) into a body cavity. Insufflation has many medical uses, most notably as a route of administration for various drugs. Medical uses Surgery Gases are often insufflated into a body cavity to inflate the cavity for more workroom, e.g. during laparoscopic surgery. The most common gas used in this manner is carbon dioxide, because it is non-flammable, colorless, and dissolves readily in blood. Diagnostics Gases can be insufflated into parts of the body to enhance radiological imaging or to gain access to areas for visual inspection (e.g. during colonoscopy). Respiratory assistance Oxygen can be insufflated into the nose by nasal cannulae to assist in respiration. Mechanical insufflation-exsufflation simulates a cough and assists airway mucus clearance. It is used with patients with neuromuscular disease and muscle weakness due to central nervous system injury. Glossopharyngeal insufflation is a breathing technique that consists of gulping boluses of air into the lungs. It is also used by breath-hold divers to increase their lung volumes. Positive airway pressure is a mode of mechanical or artificial ventilation based on insufflation. Pump inhalers for asthmatics deliver aerosolized drugs into the lungs via the mouth. However, the insufflation by the pump is not adequate for delivery to the lungs, necessitating an active inhalation by the patient. Anesthesia and critical care Insufflated gases and vapors are used to ventilate and oxygenate patients (oxygen, air, helium), and to induce, assist in or maintain general anaesthesia (nitrous oxide, xenon, volatile anesthetic agents). Positive airway pressure is a mode of mechanical or artificial ventilation based on insufflation. Nasal drug administration Nasal insufflation is the most common method of nasal administration. Other methods are nasal inhalation and nasal instillation. Drugs administered in this way can have a local effect or a systemic effect. The time of onset for systemic drugs delivered via nasal administration is generally only marginally slower than if given intravenously. While what can be defined as "marginal" is surely debatable, a much more appropriate use of the previous sentence would arguably apply when comparing drug onset rates via non-IV, parenteral administration routes, such as Intramuscular, Intradermal, or Subcutaneous injection. While nasal administration has the potential capacity to result in increased onset times relative to oral use for specific drugs, it is typically slower in onset than even rectal administration (when administered in liquid form utilizing a