Dysphagia is a frequent symptom that has an impact on prognosis of the critically ill patient. Studies in unselected ICU patient populations revealed the presence of dyphagia in more than 50% of the patiente, and in patients on neurological ICUs dysphagia is thought to be present in even more than 90% of the patients. Dysphagia in critically ill patients is a significant predictor of complications, especially aspiration pneumonia, reintubation and mortality. Still, the access to adequate diagnostic and therapeutic procedures is often limited. This chapter offers a comprehensive overview of the pathophysiology and the diagnostic and therapeutic approach in neurogenic dysphagia.

Managing the mechanical ventilator in critical illness is far from formulaic. Criteria of intubation are rarely contemplated when a patient is struggling to maintain a patent airway. Once the airway is secured, adjustments in ventilator settings and modes are continuously made, and there is a fair amount of trial and error. Weaning from the ventilator is not standardized (and probably never will be), and protocols (if there are any) are based on consultant preferences and mostly experience. The consensus statement of the European Society of Intensive Care Medicine on mechanical ventilation (MV) in acute brain injury has clearly shown that evidence for certain approaches was either insufficient or lacking and that a substantial amount of research is needed to demonstrate the feasibility, safety, and efficacy of different management approaches in this category of patients.

This chapter reviews considerations in each intervention during the patient’s clinical trajectory of ventilation in the neurosciences ICU. The reader will find that early intubation and mechanical ventilation are initiated because patients cannot protect their airways or have insufficient respiratory drive to maintain oxygenation and normocarbia.

Respiratory dysfunction can occur at one or more of the following levels: central neurons including the upper motor neuron, brainstem regions of respiratory control. lower motor neurons, peripheral motor nerves, the neuromuscular junction and the respiratory muscles. Any acute or chronic lesion or condition that affects regions of respiratory control can affect the respiratory system by altering breathing pattern and respiratory drive, leading to central breathing irregularities. Dysfunction of lower motor neurons, the peripheral motor nerves, the neuromuscular junction and the muscle typically results in an impairment of the lower motor neurons, the peripheral motor nerves, the neuromuscular junction or the muscle typically results in an impairment of the respiratory pump which commonly leads to chronic hypercapnia, also called respiratory failure type 2. Moreover, weakness of bulbar muscles can cause an airway obstruction resulting in apneic periods with hypercapnia and hypoxemia. Of note, central and peripheral alterations simultaneously affect ventilation in some disorders, which highlights the need for a specific and sometimes individual diagnostic approach. Considering the impact of respiratory insufficiency on morbidity and mortality, the respiratory function must be assessed and monitored regularly.

Comprehensive knowledge of the anatomy and physiology of the respiratory system is crucial in respiratory medicine. A profound understanding of physiology allows the practitioner to deduce pathological processes and initiate therapeutic steps based on rational decisions. The choice of a suitable ventilation mode or setting typically stems from an understanding of the pathophysiological processes. Understanding the respiratory chain at the cellular level, ventilation and perfusion, as well as the delicate interplay of macroscopic and microscopic mechanisms, supports the development of precise and individualized ventilation strategies. Knowledge of mucociliary clearance and the various lung volumes is also crucial to ensure optimal management of tracheobronchial secretions, oxygen supply and CO2 elimination.