Volume Control Ventilator

Another important intervention was to maintain the head of the bed at 30-45 degrees and position L.M.’s left lung into a dependent position to improve ventilation and perfusion. L.M.’s O2 was decreased to 63 and her CO2 was increased to 50. According to the IHI, it is recommended to elevate the bed to 30- 45 degrees to improve ventilation. Patients that lay in the supine position have lower spontaneous tidal volumes on pressure support ventilation compared to those laying at more of an angle (Institute for Healthcare Improvement, 2012). In regards to positioning, when the least damaged portion of the lung is placed in a dependent position it receives preferential blood flow. This redistribution of blood flow helps match ventilation and perfusion, therefore, improving gas exchange (Lough, Stacy & Urden, 2010). Implementing these interventions combined with respiratory therapy, significantly improved the blood gas values for oxygen and carbon dioxide levels.

The Ventilatory threshold was reached at 5 minutes or stage 3 for patient 92 C. The ventilatory threshold is important because it indicates the point at which the blood lactate acid increases non-linearly. It indicates that there is an increase in the lactate acid level in the blood as well as the excess carbon dioxide (Kenny et al., 2015). The increase in carbon dioxide will stimulate chemoreceptors to increase ventilation. The ventilatory threshold is related to the anaerobic threshold which refers to the increase in carbon dioxide and indicates that the body has shifted towards anaerobic metabolism (Kenny et al., 2015).

Due to the mechanical ventilator, it is able to assist in oxygen perfusion to all of her tissue. Thus, the lungs will be able to expand appropriately.

Even though the consequence of saline instillation on a ventilator patient in the acute care setting is pneumonia or the patient may become hemodynamically unstable, this practice remain contentious, the practice of this procedure will also decrease the oxygenation. (Ayhan, et al., 2015),

Stretch-induced lung injury may not occur if lung compliance is not greatly reduced. However, the benefit of ventilation with a lower tidal volume was independent of the static compliance of the respiratory system at base line, suggesting that the lower tidal volume was advantageous regardless of lung compliance. Variations in chest-wall compliance, which contributes to compliance of the respiratory system and is reduced in many patients with acute lung injury and the acute respiratory distress syndrome,39 may have obscured a true interaction between tidal volume and base-line lung compliance.

Airway pressure release ventilation (APRV) is a fairly new mode of ventilation, just becoming available in the U.S. in the mid-1990’s. APRV is “inverse ratio, pressure controlled, intermittent mandatory ventilation with unrestricted spontaneous breathing and it is based on the principle of open lung approach”. (Daoud, Farag, & Chatburn, 2012) The open lung approach is “concept of maximizing and maintaining alveolar recruitment throughout the ventilatory cycle by potentially ventilating the lung on the steep portion of the pressure-volume curve, thus avoiding over-distention on inspiration and alveolar collapse on exhalation”. (2012) APRV “was first used and described in 1987 as CPAP with an intermittent pressure release phase. Continuous airway pressure is applied to maintain adequate lung volume and improve alveolar recruitment. It is a pressure-limited, time-cycled, volume-variable mode of ventilation.” (2012)

Sometimes when a patient is on the more common form of mechanical ventilation for an extended time or if the patient has undergone respiratory failure, their respiratory muscles have a tendency to become weak. With the use of this biphasic cuirass ventilation method they can have the opportunity to build and strengthen those muscles which, in return, can allow them to be weaned from the ventilator

ation that I will be discussing is Airway Pressure Release Ventilation (APRV). I have not had an opportunity to use this mode, so I thought I would research it for this assignment. “The degree of ventilator support with APRV is determined by the duration of the two CPAP levels and the mechanically delivered tidal volume. Depends mainly on respiratory compliance and the difference between the CPAP levels. By design, changes in ventilatory demand do not alter the level of mechanical support during APRV. When spontaneous breathing is absent, APRV is not different from conventional pressure-controlled, time-cycled mechanical ventilation”( Putensen, C. )APRV is a form of improved pressure ventilation allowing unrestricted spontaneous breath at an

Consequently, there are numerous benefits of Neurally Adjusted Ventilation Assist (NAVA) for patients meeting the qualifications to both the patient and the medical team. First of all, the EdiCatheter can be used as an assessment tool for the patient. If you were to drop the catheter down a patient’s esophagus you could assess the diaphragm’s muscle strength which would determine if there was a possible neuromuscular problem occurring. (Kylie- KC Children’s) A patient placed on NAVA will also require less sedation to maintain comfortability, as a result this will let the patient’s respiratory muscles work while still being supported. NAVA will also help the nurses and doctors determine the appropriate level of sedation based upon the ventilator

The results for simulated airway restriction are shown at figure and table 3. Airway restriction prevents air from diffusing into pulmonary arteries as a kind of blockage in the lungs. Based on the data, peak inspiratory flow, peak expiratory flow, forced vital capacity, forced expired volume in one second, and the ratio FEV1/FVC are affected by the simulated restricted airflow. Peak respiratory flow, peak expiratory flow, and forced expired volume in one second have lower values in the restricted airway. The forced vital capacity is higher in the restricted airway simulation. The ratio FEV1/FVC which is 76% in an unrestricted airway dropped to 30% in the restricted airway simulation. This means that restricted airway is often accompanied by

There are numerous other techniques used to prevent VAP. Like many respiratory problems the head of the bed should always be elevated to between 30 and 45 degrees to prevent aspiration of fluids and sputum. The tubing for the ventilator should only be changed on a as needed basis. The continuous changing of tubes moves the bacteria and can introduce new bacteria into the respiratory system. Patients should also receive “sedation vacations” and prophylaxis medications to prevent peptic ulcers. Weaning of the mechanical ventilator should also be done as soon as possible

Lung recruitment maneuvers (RMs), are ventilator strategies in which the main goal is to restore the functional residual capacity (FRC) in order to normalize lung function and to avoid the pathogenesis of ventilator-induced lung injury (VILI) (10). These maneuvers are based in the premise described by Lachmann a few decades ago, taking into account the Young-Laplace equation states: the lungs can be opened by applying high pressures in the airways and then keep them open in time by using enough positive end expiratory pressure (PEEP)

The centre can pick up PH levels in the blood and receives information via chemoreceptors around the body which detect the change in pH levels. We can see if there is a change of carbon dioxide levels in the blood by noticing the change in PH. Ventilation and diffusion will increase drastically through the respiratory system in a reaction to exercise your breathing rate and debt will increase if your ventilation rises, the inspiratory centre controls this by stimulating the diaphragm and external intercostal muscles. The expiratory centre also controls this by being able to also stimulate the expiratory muscles which happen to be the internal intercostal muscles, oblique’s and rectus abdomens. This causes a forced expiration which reduces the duration of inspiration. Tidal volume is the amout of air taken in and relsed from the body in each breath so in vigerous exercise your tidal volume will be much higher contrasting with your body at a normal relaxed pace This is usually around 500cm cubed. Tidal volume increases to around 3-4 litres during exercise, this increase takes place as your breathing increases dramatically to compensate for the oxygen debt in your muscles . increasing the tidal volume is a good thing, it flushes out carbon dioxide and allows us to inhale plenty more oxygen to be

Most patients undergoing general anesthesia for surgical procedures require mechanical ventilation. One of the biggest challenges facing clinicians providing mechanical ventilatory support today is managing the balance between providing adequate gas exchange and avoiding lung injury associated with positive pressure ventilation. Patients with respiratory failure need adequate tissue oxygenation and acid-base balance; however, the lungs are fragile structures that can be injured by over-distension, alveolar collapse and reopening, and high oxygen exposure. This challenge in providing “lung protective ventilation” is made more difficult by the fact that lung injury is often heterogeneous and thus what may benefit gas exchange in one region (e.g., higher pressure) may worsen injury in another.

5. Does the use of 1) small tidal volume ventilation or 2) pressure-limited ventilation strategies affect outcome in ALI related to infective airway diseases?