SIMV

SIMV

abbr.

spontaneous intermittent mandatory ventilation

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synchronized intermittent mandatory ventilation (SIMV)

[sing′krənīzd]

periodic assisted mechanical ventilation synchronized with the patient's breathing. Spontaneous breathing by the patient occurs between the assisted mechanical breaths, which occur at preset intervals. The ventilator will provide a mechanical breath if the patient fails to do so within the set interval.

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ventilation [ven″tĭ-la´shun]

1. the process or act of supplying a house or room continuously with fresh air.

2. in respiratory physiology, the process of exchange of air between the lungs and the ambient air; see alveolar ventilation and pulmonary ventilation. See also respiration (def. 1). Called also breathing.

3. in psychiatry, verbalization of one's problems, emotions, or feelings.

alveolar ventilation a fraction of the pulmonary ventilation, being the amount of air that reaches the alveoli and is available for gas exchange with the blood.

assist/control mode ventilation positive pressure ventilation in the assist-control mode; if the spontaneous ventilation rate falls below a preset level, the ventilator enters the control mode.

assisted ventilation artificial respiration.

assist mode ventilation positive pressure ventilation in which the ventilator is in the assist-control mode; see also control mode ventilation and assist/control mode ventilation.

controlled ventilation (control mode ventilation) positive pressure ventilation in which the ventilator is in control mode, with its cycle entirely controlled by the apparatus and not influenced by the patient's efforts at spontaneous ventilation.

high-frequency ventilation a technique of mechanical ventilation that uses very high rates (over 80 breaths per minute) and small tidal volumes (equal to or less than dead space); it may either be positive pressure ventilation or be delivered in the form of frequent jets of air. It is used to lower the peak airway pressure applied to the lung, thus decreasing the risk of barotrauma.

high-frequency jet ventilation a type of high-frequency ventilation characterized by delivery of gas through a small catheter in the endotracheal tube.

high-frequency percussive ventilation a type of high-frequency ventilation characterized by delivery of pressure-limited breaths in short bursts of gas from a venturi mask.

high-frequency positive pressure ventilation a type of high-frequency ventilation characterized by low compressible volume circuit and tidal volume delivery of 3 to 4 mL per kg.

impaired spontaneous ventilation a nursing diagnosis accepted by the North American Nursing Diagnosis Association, defined as a state in which an individual's decreased energy reserves result in inability to maintain breathing adequate to support life. See also spontaneous ventilation.

intermittent mandatory ventilation (IMV) a type of control mode ventilation in which the patient breathes spontaneously while the ventilator delivers a prescribed tidal volume at specified intervals and allows the patient to breathe spontaneously between cycles. The ventilator rate is set to maintain the patient's Pa_CO2 at desired levels and is reduced gradually to zero as the patient's condition improves. See also intermittent positive-pressure breathing.

intermittent mandatory ventilation, synchronized (SIMV) positive pressure ventilation in which the patient breathes spontaneously while the ventilator delivers a positive-pressure breath at intervals that are predetermined but synchronized with the patient's breathing.

intermittent positive pressure ventilation (IPPV) intermittent positive pressure breathing.

maximal voluntary ventilation (maximum voluntary ventilation (MVV)) the maximum volume that can be exhaled per minute by the patient breathing as rapidly and deeply as possible. Called also maximal breathing capacity.

mechanical ventilation

1. ventilation accomplished by extrinsic means, usually distinguished as either negative pressure or positive pressure ventilation. See also spontaneous ventilation.

2. in the nursing interventions classification, a nursing intervention defined as the use of an artificial device to assist a patient to breathe.

minute ventilation the total volume of gas in liters expelled from the lungs per minute. See also minute volume. Called also total ventilation.

negative pressure ventilation a type of mechanical ventilation in which negative pressure is generated on the outside of the patient's chest and transmitted to the interior of the thorax in order to expand the lungs and allow air to flow in; used primarily with patients having paralysis of the chest muscles. See also ventilator.

noninvasive ventilation mechanical ventilation that does not use an artificial airway, such as positive pressure ventilation with a nasal or face mask.

partial liquid ventilation ventilatory support in which the lungs are filled to the level of the functional residual capacity with a liquid perfluorocarbon; mechanical ventilation is then superimposed and oxygen and carbon dioxide are transferred through the liquid.

positive pressure ventilation any of numerous types of mechanical ventilation in which gas is delivered into the airways and lungs under positive pressure, producing positive airway pressure during inspiration; it may be done via either an endotracheal tube or a nasal mask. See also ventilator.

pressure control ventilation positive pressure ventilation in which breaths are augmented by air at a fixed rate and amount of pressure, with tidal volume not being fixed; used particularly for patients with acute respiratory distress syndrome.

pressure support ventilation positive pressure ventilation in which the patient breathes spontaneously and breathing is augmented with air at a preset amount of pressure, with tidal volume not being fixed.

proportional assist ventilation positive pressure ventilation in which the ventilator can sense the patient's level of inspiratory flow and deliver pressure support to achieve a given tidal volume.

pulmonary ventilation a measure of the rate of ventilation, referring to the total exchange of air between the lungs and the ambient air, usually in liters per minute.

spontaneous ventilation term used to denote breathing accomplished naturally, without any artificial aids, as opposed to mechanical ventilation and other forms of artificial respiration.

total ventilation minute ventilation.

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SIMV

synchronized intermittent mandatory ventilation.