Two methods of weaning persons with quadriplegia from mechanical ventilators

Management of acute cervical spinal cord injury in the non-specialist intensive care unit: a narrative review of current evidence

Each year approximately one million people suffer spinal cord injury, which has significant physical, psychosocial and economic impacts on patients and their families. Spinal cord rehabilitation centres are a well-established part of the care pathway for patients with spinal cord injury and facilitate improvements in functional independence and reductions in healthcare costs. Within the UK, however, there are a limited number of spinal cord injury centres, which delays admission. Patients and their families often perceive that they are not receiving specialist care while being treated in non-specialist units. This review aimed to provide clinicians who work in non-specialist spinal injury centres with a summary of contemporary studies relevant to the critical care management of patients with cervical spinal cord injury. We undertook a targeted literature review including guidelines, systematic reviews, meta-analyses, clinical trials and randomised controlled trials published in English between 1 June 2017 and 1 June 2023. Studies involving key clinical management strategies published before this time, but which have not been updated or repeated, were also included. We then summarised the key management themes: acute critical care management approaches (including ventilation strategies, blood pressure management and tracheostomy insertion); respiratory weaning techniques; management of pain and autonomic dysreflexia; and rehabilitation.

Respiratory management in the patient with spinal cord injury

Spinal cord injuries (SCIs) often lead to impairment of the respiratory system and, consequently, restrictive respiratory changes. Paresis or paralysis of the respiratory muscles can lead to respiratory insufficiency, which is dependent on the level and completeness of the injury. Respiratory complications include hypoventilation, a reduction in surfactant production, mucus plugging, atelectasis, and pneumonia. Vital capacity (VC) is an indicator of overall pulmonary function; patients with severely impaired VC may require assisted ventilation. It is best to proceed with intubation under controlled circumstances rather than waiting until the condition becomes an emergency. Mechanical ventilation can adversely affect the structure and function of the diaphragm. Early tracheostomy following short orotracheal intubation is probably beneficial in selected patients. Weaning should start as soon as possible, and the best modality is progressive ventilator-free breathing (PVFB). Appropriate candidates can sometimes be freed from mechanical ventilation by electrical stimulation. Respiratory muscle training regimens may improve patients' inspiratory function following a SCI.

The changing landscape of spinal cord injury

In the past quarter century, spinal cord injury medicine has welcomed the proliferation of new medications and technologies that improve the survival and quality of life for people with spinal cord injury, but also endured the failure of strategies we hoped would salvage the cord in the acute phase. Surgical decompression and spinal stabilization should be pursued whenever indicated and feasible; however, there is no compelling evidence that early decompression facilitates neurological improvement. Methylprednisolone, the subject of over two decades of trials, has proven to be of marginal benefit in improving functional outcome. Recent advances in the management of the respiratory, cardiovascular, autonomic, endocrine, skeletal and integumentary systems have not only changed morbidity and survival of spinal cord injury patients but also improved quality of life. Progress has been made in the early diagnosis and effective treatment of cardiac arrhythmias, neurogenic shock, autonomic dysreflexia and orthostatic hypotension. Aggressive respiratory care for high cervical level of injury patients should include an option for phrenic nerve pacing as it is a viable rehabilitative strategy for appropriately selected patients. Pressure ulcers remain a significant psychological, financial, and functional burden for many people with SCI and for healthcare providers. This area will continue to require further work on early prevention and education. Despite extensive scientific and clinical data on neurogenic osteoporosis, there is no consensus regarding the best pharmacotherapeutic agents, dosing regimens, or rehabilitative strategies for prevention and treatment of bone loss. This chapter will focus on the advances.

A systematic review of intensive cardiopulmonary management after spinal cord injury

Intensive cardiopulmonary management is frequently undertaken in patients with spinal cord injury (SCI), particularly due to the occurrence of neurogenic shock and ventilatory insufficiency and in an attempt to reduce secondary injury. We undertook a systematic review of the literature to examine the evidence that intensive care management improves outcome after SCI and to attempt to define key parameters for cardiopulmonary support/resuscitation. We review the literature in five areas: management of SCI patients in specialized centers, risk in SCI patients of cardiopulmonary complications, parameters for blood pressure and oxygenation/ventilation support following SCI, risk factors for cardiopulmonary insufficiency requiring ICU care after SCI, and preventative strategies to reduce the risks of cardiopulmonary complications in SCI patients. The literature supports that, in light of the significant incidence of cardiorespiratory complications, SCI patients should be managed in a monitored special care unit. There is weak evidence supporting the maintenance of MAP >85 mmHg for a period extending up to 1 week following SCI.

Baclofen pump intervention for spasticity affecting pulmonary function

INTRODUCTION

Muscle spasticity may adversely affect pulmonary function after spinal cord injury (SCI). However, there is limited information regarding the treatment of spasticity as a determinant of pulmonary function. This study presents the case of a man with C4 tetraplegia who had severe spasticity and difficulty weaning from ventilatory support.

METHODS

Case presentation.

RESULTS

Severe spasticity likely contributed to respiratory compromise in this patient. Successful and rapid weaning from the ventilator occurred within 3 weeks of baclofen pump placement.

CONCLUSIONS

Randomized clinical trials among SCI patients with significant spasticity are needed to determine whether intervention with a baclofen pump facilitates earlier ventilatory weaning.

Weaning of the neurologically impaired patient

Many studies have been published on weaning patients from mechanical ventilation, but few have addressed the unique needs of patients with neurologic impairment. Typically, neuroscience patients remain intubated because of concerns over airway protection or neuromuscular weakness. This article discusses special weaning considerations for this patient population. Neurologic-specific weaning trends from a comprehensive ventilator weaning program are also presented.

Respiratory training for a person with C3-C4 tetraplegia

Persons with high tetraplegic spinal cord injuries commonly have respiratory complications that may negatively impact their health and quality of life. Treatment of these respiratory problems often requires significant health care dollars. This case report describes and evaluates the effect of a year-long respiratory intervention, which included inspiratory muscle training and positive expiratory pressure therapy, for a person with C3-C4 tetraplegia. The intervention improved both inspiratory muscle force and pulmonary function values. Respiratory infections, frequency of suctioning and physiotherapy treatment time decreased progressively throughout the intervention. There were no admissions to the acute care hospital after the interventions began. This intervention improved the participant's health and well being and reduced costs to the health care system.

Is there a preferred technique for weaning the difficult-to-wean patient? A systematic review of the literature

OBJECTIVE

To answer the following question: In difficult-to-wean patients, which of the three commonly used techniques of weaning (T-piece, synchronized intermittent mandatory ventilation, or pressure support ventilation) leads to the highest proportion of successfully weaned patients and the shortest weaning time?

DATA SOURCES

Computerized literature searches in MEDLINE (1975-1996), Cinahl (1982-1996), and Healthplan (1985-1996), exploding all Mesh headings pertaining to Mechanical Ventilation and Weaning. Searches were restricted to the English language, adults, and humans. Personal files were hand searched, and references of selected articles were reviewed.

STUDY SELECTION

a)

POPULATION

Patients requiring a gradual weaning process from the ventilator (either requiring prolonged initial ventilation of >72 hrs or a failed trial of spontaneous breathing after >24 hrs of ventilation); b)

INTERVENTIONS

At least two of the following three modes of weaning from mechanical ventilation must have been compared: T-piece, synchronized intermittent mandatory ventilation, or pressure support ventilation; c)

OUTCOMES

At least one of the following: weaning time (time from initiation of weaning to extubation) or successful weaning rate (successfully off the ventilator for >48 hrs); and d)

STUDY DESIGN

Controlled trial.

DATA EXTRACTION

Two reviewers independently reviewed the articles and graded them according to their methodologic rigor. Data on the success of weaning and the time to wean were summarized for each study.

DATA SYNTHESIS

The search strategy identified 667 potentially relevant studies; of these, 228 had weaning as their primary focus, and of these, 48 addressed modes of ventilation during weaning. Only 16 of these 48 studies had one of the specified outcomes, and only ten of these were controlled trials. Of the ten trials, only four fulfilled all our selection criteria. The results of the trials were conflicting, and there was heterogeneity among studies that precluded meaningful pooling of the results.

CONCLUSIONS

There are few trials designed to determine the most effective mode of ventilation for weaning, and more work is required in this area. From the trials reviewed, we could not identify a superior weaning technique among the three most popular modes, T-piece, pressure support ventilation, or synchronized intermittent mandatory ventilation. However, it appears that synchronized intermittent mandatory ventilation may lead to a longer duration of the weaning process than either T-piece or pressure support ventilation. Finally, the manner in which the mode of weaning is applied may have a greater effect on the likelihood of weaning than the mode itself.