Neuroprognostication, the focus of this book, is crucial toward the management of the highly complex patient in the neurological intensive care unit (Neuro ICU). It is of primary importance to understand the nature of the disease and the potential for recovery. Informed prognostication by neurologically trained physicians has been hypothesized to be a significant reason for the improved outcomes of neurological patients managed in a Neuro ICU versus general medical ICUs.[1]

Decisions surrounding withdrawal of life-sustaining therapies (WLST) are highly dependent on prognosis. In a retrospective study of Neuro ICU patients who were terminally extubated, family members surveyed most frequently cited quality of life, prognosis, and the patient’s previously known wishes as “very important” in their decision to remove life-sustaining therapy.[2]

Evidence-based prognostication in the Neuro ICU is difficult, and may be biased by the effect of WLST on patient mortality.

Neuromuscular diseases and respiratory failure are common problems encountered in both neurologic and medical intensive care units. Neuromuscular respiratory failure can be caused by diseases of the motor neuron, peripheral nerve, neuromuscular junction, or muscle. Thus, localization of the disorder is essential for adequate management.

One of the most frequent neurological consultations in any medical or surgical intensive care unit (ICU) is for generalized weakness. Patients admitted to ICUs may have a number of factors leading to neuromuscular problems, including metabolic derangements, nutritional deficiencies, acquired diseases, and structural problems of the neuromuscular system. Weakness in the setting of a critically ill patient can have profound effects on patient morbidity and mortality with increased length of hospital stay, medical complications, and cost [1]. In this chapter we have highlighted the various causes of generalized weakness in ICU patients, and the diagnostic approach and management of these illnesses.

Neuromuscular diseases and respiratory failure are common processes encountered in both neurologic and medical intensive care units. Problems can be encountered anywhere along the peripheral nervous system. Neurogenic respiratory failure can be localized to diseases of the motor neuron, peripheral nerve, neuromuscular junction, or muscle.

This chapter provides a broad overview of the clinical presentation of neuromuscular respiratory failure and reviews diagnostic criteria and treatment for specific neuromuscular diseases.

NEUROMUSCULAR RESPIRATORY FAILURE: CLINICAL FEATURES

Patients with neuromuscular respiratory weakness need to be closely followed with pulmonary function tests. These should include at least vital capacities, negative inspiratory forces, and expiratory flow volumes. Part of the need for close monitoring is due to the often unreliability of the clinical exam.

1. ▪The clinical signs and symptoms of patients with neuromuscular failure may differ and can present with varying signs and symptoms of respiratory, bulbar, or appendicular weakness.

2. ▪Patients may complain of dyspnea or a vague sense of uneasiness. Brow sweating is common.

3. ▪In many circumstances a patient with neuromuscular failure will develop the typical signs and symptoms of respiratory difficulties (tachypnea, tachycardia, accessory muscle use, decreased cough, etc.).

A patient with a rapidly ascending paralysis, an acute dysautonomia, or neuromuscular junction inhibition may not be able to manifest the signs and symptoms typically encountered in a patient with impending respiratory arrest secondary to primarily pulmonary processes. Thus a decision on the timing of endotracheal intubation should be based on the decline of pulmonary function tests and not necessarily on the clinical presentation of the patient. In the above circumstances patients may appear well until the need for urgent intubation.