Mechanical Ventilation

One of the most important avenues of respiratory management is mechanical ventilation. Over the past 40 years, there has been an increase in the incidence of cervical cord injuries and, as a result, an increase in the use of mechanical ventilation (Devivo 2012; Jackson et al. 2004). Patients can be ventilated with non-invasive mask ventilation or more invasive endotracheal or transtracheal (with a tracheostomy) ventilation. Often these more invasive procedures are needed to allow for the ability to suction excess secretions to prevent the development of complications such as atelectasis or pneumonia (Gregoretti et al. 2005). Patients may experience more than one type of ventilation during their hospital stay as their needs adjust (i.e., they may initially be intubated with endotracheal ventilation and later proceed to transtracheal intubation to assist in ventilator weaning). In addition to the delivery of ventilation, there are several modes of ventilation used for patients that vary in the amount of volume or pressure controlled based on pre-set variables to maximize lung function. For example, intermittent positive pressure breathing is one of the oldest ventilation strategies in which all inspirations are provided through the application of positive pressure to the airway. Its use is common in acute SCI patients, yet its general efficacy is still largely unknown (Denehy & Berney, 2001) and is understudied in the SCI population. Intubation for mechanical ventilation often occurs at the time of injury to manage respiratory failure or to protect the airway in cases of complete SCI between C1 and C5 (Berney et al. 2011). In contrast, incomplete injuries lower than C5, where the airway is not immediately compromised or at risk, ventilation is often still initiated approximately four days after injury when levels of carbon dioxide rise in the blood due to difficulty expiring (Galeiras Vazquez et al. 2013). Although ventilatory needs are unique for each patient, it is useful to determine which factors predict the need for mechanical ventilation in an effort to develop practice guidelines and reduce overall hospital stay (Casha & Christie, 2011). Certain risk factors of mechanical ventilation have also been identified (Montoto-Marques et al., 2018). One observational study found, not unexpectedly, that patients with ASIA grades A and B were more likely to require mechanical ventilation, as well as those with higher injury severity scores (Montoto-Marques et al., 2018). The last factor discussed by this study was the role that gender played. Males were reported to require higher levels of mechanical ventilation than females (Montoto-Marques et al., 2018); however, this could be due to the overwhelming number of men in this study compared to women. Other factors include complete injuries, high Injury Severity Score (ISS), and compounding injuries (Velmahos et al. 2003; Como et al. 2005; Seidl et al. 2010).