Pharmacological Interventions for Pulmonary Function Improvement During Acute SCI
Pharmacological treatments for pulmonary function in patients with SCI aim to improve breathing and coughing. This area of research has been explored largely in patients with chronic SCI, where bronchodilators and anabolic steroids have shown varying degrees of success (see the rehabilitation chapter on Respiratory Management (Rehab).
Discussion
For cervical SCI, the imbalance of parasympathetic drive leads to bronchoconstriction and bronchosecretion. Medications such as salbutamol (albuterol in the USA) and ipratropium are commonly used during acute hospitalization. Other medications that are commonly used are mucolytics for secretion management, such as scopolamine, atropine, glycopyrrolate, N-Acetylcysteine, hypertonic saline. There is not any evidence in acute SCI.
Other medications that have been piloted is the anabolic steroid called Oxandralone (Halstead et al. 2010) and theophylline (Tzelepis et al. 2006) to improve respiratory function; but these studies were done in patients with chronic SCI.
Although several types of bronchodilators and secretolytic agents exist, only two have been tested within the acute SCI population. Based on one study alone, bronchodilator therapy with salbutamol provided effective short-term improvements in lung function (Barratt et al. 2012). Barratt et al. (2012) showed that salbutamol increased forced vital capacity and forced expiratory volume; these improvements were maintained for half an hour. Peak cough expiratory flow also improved, but this effect deteriorated after ten minutes (Barratt et al. 2012).
The second RCT by Li et al. (2012) studied the secretolytic agent, ambroxol, after surgical spinal cord decompression and stabilization and demonstrated more long-term improvements in pulmonary functioning. Oxygenation indexes remained elevated after five days, and patients had fewer episodes of pneumonia and hypoxemia overall (Li et al. 2012). These two studies showed that pharmacological interventions may be helpful in improving breathing and reducing infection, but long-term treatments (>1 month) and the efficacy of alternative drugs remain unknown (Barratt et al. 2012; Li et al. 2012).
Conclusion
There is level 1b evidence (from one RCT: Barratt et al. 2012) that bronchodilator therapy with salbutamol may improve pulmonary function compared to placebo in patients with acute SCI.
There is level 1b evidence (from one RCT: Li et al. 2012) that high dose ambroxol may reduce postoperative respiratory complications and increase blood oxygenation following surgical spinal cord decompression and stabilization compared to placebo in patients with acute cervical SCI.
