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Spontaneous Breathing Trial
A spontaneous breathing trial is a test for patients on mechanical ventilation, before they can be weaned from the ventilator, i.e. return to normal breathing. The weaning process depends closely on the patient's pathology, but the final common pathway to ventilator independence always includes at least one trial of spontaneous breathing. Trials of spontaneous breathing have been shown to accurately predict the success of spontaneous breathing.Yang K, Tobin MJ, A prospective study of indexes predicting the outcome of weaning from mechanical ventilation. N Engl J Med 1991;324:1445-1450 Indications for trials of spontaneous breathing * Fraction of inspired oxygen (FIO2) less than 50% * Positive end expiratory pressure (PEEP) less than 8 cm water * "Minimal vent settings" ** e.g., ratio of arterial partial pressure of oxygen to FIO2 ( P/F ratio) in the vicinity of 400 Valid methods In all of the methods below, the common endpoint measurement is a Rapid Shallow Breathing Inde ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mechanical Ventilation
Mechanical ventilation, assisted ventilation or intermittent mandatory ventilation (IMV), is the medical term for using a machine called a ventilator to fully or partially provide artificial ventilation. Mechanical ventilation helps move air into and out of the lungs, with the main goal of helping the delivery of oxygen and removal of carbon dioxide. Mechanical ventilation is used for many reasons, including to protect the airway due to mechanical or neurologic cause, to ensure adequate oxygenation, or to remove excess carbon dioxide from the lungs. Various healthcare providers are involved with the use of mechanical ventilation and people who require ventilators are typically monitored in an intensive care unit. Mechanical ventilation is termed invasive if it involves an instrument to create an airway that is placed inside the trachea. This is done through an endotracheal tube or nasotracheal tube. For non-invasive ventilation in people who are conscious, face or nasal mask ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ventilator
A ventilator is a piece of medical technology that provides mechanical ventilation by moving breathable air into and out of the lungs, to deliver breaths to a patient who is physically unable to breathe, or breathing insufficiently. Ventilators are computerized microprocessor-controlled machines, but patients can also be ventilated with a simple, hand-operated bag valve mask. Ventilators are chiefly used in intensive-care medicine, home care, and emergency medicine (as standalone units) and in anesthesiology (as a component of an anesthesia machine). Ventilators are sometimes called "respirators", a term commonly used for them in the 1950s (particularly the "Bird respirator"). However, contemporary medical terminology uses the word "respirator" to refer instead to a face-mask that protects wearers against hazardous airborne substances. Function In its simplest form, a modern positive pressure ventilator, consists of a compressible air reservoir or turbine, air and oxygen s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fraction Of Inspired Oxygen
Fraction of inspired oxygen (''FI''O2), corrected denoted with a capital "I", is the molar or volumetric fraction of oxygen in the inhaled gas. Medical patients experiencing difficulty breathing are provided with oxygen-enriched air, which means a higher-than-atmospheric ''FI''O2. Natural air includes 21% oxygen, which is equivalent to ''FI''O2 of 0.21. Oxygen-enriched air has a higher ''FI''O2 than 0.21; up to 1.00 which means 100% oxygen. ''FI''O2 is typically maintained below 0.5 even with mechanical ventilation, to avoid oxygen toxicity, but there are applications when up to 100% is routinely used. Often used in medicine, the ''FI''O2 is used to represent the percentage of oxygen participating in gas-exchange. If the barometric pressure changes, the ''FI''O2 may remain constant while the partial pressure of oxygen changes with the change in barometric pressure. Equations ;Abbreviated alveolar air equation :P_A \ce = \frac PAO2, PEO2, and PIO2 are the partial pressures of oxy ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Positive End Expiratory Pressure
Positive end-expiratory pressure (PEEP) is the pressure in the lungs (alveolar pressure) above atmospheric pressure (the pressure outside of the body) that exists at the end of expiration. The two types of PEEP are extrinsic PEEP (PEEP applied by a ventilator) and intrinsic PEEP (PEEP caused by an incomplete exhalation). Pressure that is applied or increased during an inspiration is termed pressure support. Intrinsic (auto-) PEEP Auto-PEEP is an incomplete expiration prior to the initiation of the next breath causes progressive air trapping (hyperinflation). This accumulation of air increases alveolar pressure at the end of expiration, which is referred to as auto-PEEP. Auto-PEEP develops commonly in high minute ventilation (hyperventilation), expiratory flow limitation (obstructed airway) and expiratory resistance (narrow airway). Once auto-PEEP is identified, steps should be taken to stop or reduce the pressure build-up. When auto-PEEP persists despite management of its und ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
P/F Ratio
The Horowitz index or Horovitz index (also known as the Horowitz quotient or the P/F ratio) is a ratio used to assess lung function in patients, particularly those on ventilators. It is useful for evaluating the extent of damage to the lungs. The simple abbreviation as oxygenation can lead to confusion with other conceptualizations of oxygenation index. The Horowitz index is defined as the ratio of partial pressure of oxygen in blood (PaO2), in millimeters of mercury, and the fraction of oxygen in the inhaled air (FiO2) — the ''PaO2''/''FiO2 ratio''. In healthy lungs, the Horowitz index depends on age and usually falls between 350 and 450. A value below 300 is the threshold for mild lung injury, and 200 is indicative of a moderately severe lung injury. A value below 100 is a criterion for a severe injury. The Horowitz index plays a major role in the diagnosis of acute respiratory distress syndrome Acute respiratory distress syndrome (ARDS) is a type of respirator ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Glasgow Coma Scale
The Glasgow Coma Scale (GCS) is a clinical scale used to reliably measure a person's level of consciousness after a brain injury. The GCS assesses a person based on their ability to perform eye movements, speak, and move their body. These three behaviours make up the three elements of the scale: eye, verbal, and motor. A person's GCS score can range from 3 (completely unresponsive) to 15 (responsive). This score is used to guide immediate medical care after a brain injury (such as a car accident) and also to monitor hospitalised patients and track their level of consciousness. Lower GCS scores are correlated with higher risk of death. However, the GCS score alone should not be used on its own to predict the outcome for an individual person with brain injury. Scoring The Glasgow Coma Scale is used for people above the age of two and composed of three tests: eye, verbal, and motor responses. The scores for each of these tests are indicated in the table below. The Glasgow Com ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
