Update on respiratory management of critically ill neurologic patients

Extubating to Noninvasive Ventilation: Noninvasive Ventilation from Intensive Care Unit to Home

Weaning to noninvasive ventilation in intensive care unit and bridging the patients to home with respiratory support is evolving as the technology of noninvasive ventilation is improving. In patients with chronic obstructive pulmonary disease exacerbation, timing of initiation of noninvasive ventilation is the key, as persistently hypercapnic patients show benefits. High-intensity pressure support seems to do better in comparison to low-intensity pressure support. In patients with obesity and hypercapnia, obesity hypoventilation cannot be ruled out especially in an inpatient setting, and it is crucial that these patients are discharged with noninvasive ventilation.

Respiratory repercussions of neurological diseases and how best to manage them

Introduction: The high incidence of respiratory impairments in patients with neurological diseases is recognized, but the design, dosage, and effectiveness of interventions to manage them are seen as an ongoing challenge.Areas covered: This article summarizes the evidence regarding the respiratory impairments in major neurological diseases, and how to best manage them.Expert opinion: On the balance of available evidence, respiratory impairments are part of the clinical profile of neurological diseases including Multiple Sclerosis, Stroke, and Parkinson's Disease, acquiring more importance as the pathologies progress. It is recognized that knowledge gaps remain in some areas of relevance related to respiratory function and further research is required. When considering the therapeutic options, the respiratory training emerges as the approach with most evidence. However, important questions remain unsolved: what kind, how much, and how to best include respiratory interventions is uncertain. At present, respiratory programs also fail to include clinically relevant factors such as ambulation and trunk stability.

Sodium valproate suppresses abnormal neurogenesis induced by convulsive status epilepticus

Status epilepticus has been shown to activate the proliferation of neural stem cells in the hippocampus of the brain, while also causing a large amount of neuronal death, especially in the subgranular zone of the dentate gyrus and the subventricular zone. Simultaneously, proliferating stem cells tend to migrate to areas with obvious damage. Our previous studies have clearly confirmed the effect of sodium valproate on cognitive function in rats with convulsive status epilepticus. However, whether neurogenesis can play a role in the antiepileptic effect of sodium valproate remains unknown. A model of convulsive status epilepticus was established in Wistar rats by intraperitoneal injection of 3 mEq/kg lithium chloride, and intraperitoneal injection of pilocarpine 40 mg/kg after 18–20 hours. Sodium valproate (100, 200, 300, 400, 500, or 600 mg/kg) was intragastrically administered six times every day (4-hour intervals) for 5 days. To determine the best dosage, sodium valproate concentration was measured from the plasma. The effective concentration of sodium valproate in the plasma of the rats that received the 300-mg/kg intervention was 82.26 ± 11.23 μg/mL. Thus, 300 mg/kg was subsequently used as the intervention concentration of sodium valproate. The following changes were seen: Recording excitatory postsynaptic potentials in the CA1 region revealed high-frequency stimulation-induced long-term potentiation. Immunohistochemical staining for BrdU-positive cells in the brain revealed that sodium valproate intervention markedly increased the success rate and the duration of induced long-term potentiation in rats with convulsive status epilepticus. The intervention also reduced the number of newborn neurons in the subgranular area of the hippocampus and subventricular zone and inhibited the migration of newborn neurons to the dentate gyrus. These results indicate that sodium valproate can effectively inhibit the abnormal proliferation and migration of neural stem cells and newborn neurons after convulsive status epilepticus, and improve learning and memory ability.

Primary Acute Neuromuscular Respiratory Failure

Neurologists are often called to evaluate patients with both defined and undiagnosed neuromuscular disorders when respiratory failure develops to determine if there is a neuromuscular cause. Being able to confidently diagnose neuromuscular respiratory failure and intervene appropriately is imperative, as early intervention and determination of the cause have survival implications. Outcomes are poor when the cause of neuromuscular weakness and resultant respiratory failure cannot be identified. This review discusses the clinical recognition of primary neuromuscular respiratory failure, its pathophysiology, diagnostic evaluation, and management, focusing on management of respiratory failure in the setting of Guillain-Barré syndrome and myasthenic crisis.

Successful Extubation After Weaning Failure by Noninvasive Ventilation in Patients With Neuromuscular Disease: Case Series

Objective

To report successful cases of extubation from invasive mechanical ventilation at our institution using pulmonary rehabilitation consisting of noninvasive ventilation (NIV) in neuromuscular patients with experience of reintubation.

Methods

Patients who experienced extubation failure via the conventional weaning strategy but afterwards had extubation success via NIV were studied retrospectively. Continuous end-tidal CO₂ (ETCO₂) and pulse oxyhemoglobin saturation (SpO₂) monitoring were performed. Extubation success was defined as a state not requiring invasive mechanical ventilation via endotracheal tube or tracheotomy during a period of at least 5 days.

Results

A total of 18 patients with ventilatory failure who initially experienced extubation failure were finally placed under part-time NIV after extubation. No patient had any serious or long-term adverse effect from NIV, and all patients left the hospital alive.

Conclusion

NIV may promote successful weaning in neuromuscular patients with experience of reintubation.

Noninvasive ventilation for neuromuscular respiratory failure: when to use and when to avoid

PURPOSE OF REVIEW

Neuromuscular respiratory failure can occur from a variety of diseases, both acute and chronic with acute exacerbation. There is often a misunderstanding about how the nature of the neuromuscular disease should affect the decision on how to ventilate the patient. This review provides an update on the value and relative contraindications for the use of noninvasive ventilation in patients with various causes of primary neuromuscular respiratory failure.

RECENT FINDINGS

Myasthenic crisis represents the paradigmatic example of the neuromuscular condition that can be best treated with noninvasive ventilation. Timely use of noninvasive ventilation can substantially reduce the duration of ventilatory assistance in these patients. Noninvasive ventilation can also be very helpful after extubation in patients recovering from an acute cause of neuromuscular respiratory failure who have persistent weakness. Noninvasive ventilation can improve quality of survival in patients with advanced motor neuron disorder (such as amyotrophic lateral sclerosis) and muscular dystrophies, and can avoid intubation when these patients present to the hospital with acute respiratory failure. Attempting noninvasive ventilation is not only typically unsuccessful in patients with Guillain-Barre syndrome, but can also be dangerous in these cases.

SUMMARY

Noninvasive ventilation can be very effective to treat acute respiratory failure caused by myasthenia gravis and to prevent reintubation in other neuromuscular patients, but should be used cautiously for other indications, particularly Guillain-Barre syndrome.

Non-invasive ventilation is useful in paediatric intensive care units if children are appropriately selected and carefully monitored

Non-invasive ventilation (NIV) is commonly used in paediatric intensive care units (PICUs) for respiratory failure. This review aims to improve paediatricians' understanding of NIV, by specifying technical or practical considerations, giving advice about selecting patients and presenting pertinent published data about NIV in different circumstances.

CONCLUSION

NIV is useful in PICUs if children are appropriately selected and carefully monitored. Technological advances and future clinical research will improve its use and success rate in PICU.