Predictors of hospital mortality and mechanical ventilation in patients with cervical spinal cord injury

Quality of in-hospital care in traumatic spinal column and cord injuries (TSC/SCI) in I.R Iran

PURPOSE

This study aimed to implement the Quality of Care (QoC) Assessment Tool from the National Spinal Cord/Column Injury Registry of Iran (NSCIR-IR) to map the current state of in-hospital QoC of individuals with Traumatic Spinal Column and Cord Injuries (TSCCI).

METHODS

The QoC Assessment Tool, developed from a scoping review of the literature, was implemented in NSCIR-IR. We collected the required data from two primary sources. Questions regarding health system structures and care processes were completed by the registrar nurse reviewing the hospital records. Questions regarding patient outcomes were gathered through patient interviews.

RESULTS

We registered 2812 patients with TSCCI over six years from eight referral hospitals in NSCIR-IR. The median length of stay in the general hospital and intensive care unit was four and five days, respectively. During hospitalization 4.2% of patients developed pressure ulcers, 83.5% of patients reported satisfactory pain control and none had symptomatic urinary tract infections. 100%, 80%, and 90% of SCI registration centers had 24/7 access to CT scans, MRI scans, and operating rooms, respectively. Only 18.8% of patients who needed surgery underwent a surgical operation in the first 24 h after admission. In-hospital mortality rate for patients with SCI was 19.3%.

CONCLUSION

Our study showed that the current in-hospital care of our patients with TSCCI is acceptable in terms of pain control, structure and length of stay and poor regarding in-hospital mortality rate and timeliness. We must continue to work on lowering rates of pressure sores, as well as delays in decompression surgery and fatalities.

Guidelines for neuroprognostication in adults with traumatic spinal cord injury

BACKGROUND

Traumatic spinal cord injury (tSCI) impacts patients and their families acutely and often for the long term. The ability of clinicians to share prognostic information about mortality and functional outcomes allows patients and their surrogates to engage in decision-making and plan for the future. These guidelines provide recommendations on the reliability of acute-phase clinical predictors to inform neuroprognostication and guide clinicians in counseling adult patients with tSCI or their surrogates.

METHODS

A narrative systematic review was completed using Grading of Recommendations Assessment, Development, and Evaluation methodology. Candidate predictors, including clinical variables and prediction models, were selected based on clinical relevance and presence of an appropriate body of evidence. The Population/Intervention/Comparator/Outcome/Timing/Setting question was framed as "When counseling patients or surrogates of critically ill patients with traumatic spinal cord injury, should < predictor, with time of assessment if appropriate > be considered a reliable predictor of < outcome, with time frame of assessment >?" Additional full-text screening criteria were used to exclude small and lower quality studies. Following construction of an evidence profile and summary of findings, recommendations were based on four Grading of Recommendations Assessment, Development, and Evaluation criteria: quality of evidence, balance of desirable and undesirable consequences, values and preferences, and resource use. Good practice recommendations addressed essential principles of neuroprognostication that could not be framed in the Population/Intervention/Comparator/Outcome/Timing/Setting format. Throughout the guideline development process, an individual living with tSCI provided perspective on patient-centered priorities.

RESULTS

Six candidate clinical variables and one prediction model were selected. Out of 11,132 articles screened, 369 met inclusion criteria for full-text review and 35 articles met eligibility criteria to guide recommendations. We recommend pathologic findings on magnetic resonance imaging, neurological level of injury, and severity of injury as moderately reliable predictors of American Spinal Cord Injury Impairment Scale improvement and the Dutch Clinical Prediction Rule as a moderately reliable prediction model of independent ambulation at 1 year after injury. No other reliable or moderately reliable predictors of mortality or functional outcome were identified. Good practice recommendations include considering the complete clinical condition as opposed to a single variable and communicating the challenges of likely functional deficits as well as potential for improvement and for long-term quality of life with SCI-related deficits to patients and surrogates.

CONCLUSIONS

These guidelines provide recommendations about the reliability of acute-phase predictors of mortality, functional outcome, American Spinal Injury Association Impairment Scale grade conversion, and recovery of independent ambulation for consideration when counseling patients with tSCI or their surrogates and suggest broad principles of neuroprognostication in this context.

[Perioperative management after traumatic paraplegia : Avoiding complications]

This article describes the current status of modern treatment options for traumatic spinal cord injuries with a particular focus on the perioperative phase. Along with a recognition of age-related specific features that can impact successful treatment of spinal injuries, prompt interdisciplinary treatment while adhering to the "time is spine" principle is of high importance. By considering this approach and using modern diagnostic and surgical techniques, successful surgical treatment can be achieved while taking into account individual characteristics, such as reduced bone quality, accompanying injuries as well as oncological and inflammatory rheumatic comorbidities. The preventive and treatment strategies for frequently occurring complications in the management of traumatic spinal cord injuries are presented. By considering case-specific factors, utilizing modern surgical techniques, avoiding or promptly treating typical complications and initiating interdisciplinary treatment, crucial groundwork for a successful long-term treatment of this highly debilitating and life-altering injury can be established in the perioperative phase.

In-hospital mortality rate in subaxial cervical spinal cord injury patients: a systematic review and meta-analysis

PURPOSE

To determine existing trends concerning in-hospital mortality in patients with traumatic subaxial cervical spinal cord injury (SCI) over the last four decades.

METHODS

We searched MEDLINE and EMBASE to assess the role of the following factors on in-hospital mortality over the last four decades: neurological deficit, age, surgical decompression, use of computed tomography (CT) and magnetic resonance imaging (MRI), use of methylprednisolone in the acute post-injury period, and study location (developing versus developed countries).

RESULTS

Among 3333 papers after deduplication, 21 studies met the eligibility criteria. The mortality rate was 17.88% [95% confidence interval (CI): 12.9-22.87%]. No significant trend in mortality rate was observed over the 42-year period (meta-regression coefficient = 0.317; p = 0.372). Subgroup analysis revealed no significant association between acute subaxial cervical SCI-related mortality when stratified by use of surgery, administration of methylprednisolone, use of MRI and CT imaging, study design (prospective versus retrospective study), and study location. The mortality rate was significantly higher in complete SCI (20.66%, p = 0.002) and American Spinal Injury Association impairment scale (AIS) A (20.57%) and B (9.28%) (p = 0.028).

CONCLUSION

A very low level of evidence showed that in-hospital mortality in patients with traumatic subaxial cervical SCI did not decrease over the last four decades despite diagnostic and therapeutic advancements. The overall acute mortality rate following subaxial cervical SCI is 17.88%. We recommend reporting a stratified mortality rate according to key factors such as treatment paradigms, age, and severity of injury in future studies.

Noninvasive respiratory assistance as aid for respiratory care in neuromuscular disorders

Chronic respiratory failure is a common complication of neuromuscular disease. The use of noninvasive ventilation and mechanically assisted cough can reduce symptoms of hypoventilation, slow lung function decline, improve sleep quality, and in some cases prolong survival in patients with neuromuscular disease. In this article, we review indications for the initiation of noninvasive ventilation and mechanically assisted cough as well as provide recommendations for settings and titration. We discuss the evidence supporting the use of noninvasive ventilation as an adjunct to rehabilitation in patients with neuromuscular disease. Lastly, we review the ethical considerations that are relevant to decisions regarding initiation and cessation of noninvasive ventilation. While noninvasive ventilation and mechanically assisted cough have become standards of care in many forms of neuromuscular disease, most current recommendations are based on expert opinion rather than much-needed data from prospective clinical trials and we emphasize topics requiring future research.

Thoracolumbar spine injury in Cameroon: etiology, management, and outcome

BACKGROUND

Thoracolumbar spine injury (TLSI) is a major concern worldwide despite its low prevalence. Studies demonstrate a gradual rise in annual incidence. There have been improvements in its management. However, a lot is still to be done. TLSI secondary to trauma usually occurs abruptly and leaves demeaning consequences, especially in our setting where the prognosis from several studies is poor. This study aimed to describe the etiology, management principles, and prognosis of TLSI in Douala General Hospital and as such contribute data on those aspects in the research community.

METHOD

This was a hospital-based five-year retrospective study. The study population was patients treated for TLSI in the Douala General Hospital from January 2014 to December 2018. Patients' medical records were used to retrieve data. Data analysis was done using SPSS Version 23. Logistic regression models were fitted to assess the association between dependent and independent variables. Statistical significance was set at 95% CI, with a P-value < 0.05.

RESULTS

We studied a total of 70 patients' files including 56 males. The mean age of occurrence of TLSI was 37.59 ± 14.07 years. The most common etiology was road traffic accidents (45.7%) and falls (30.0%). Half of our patients (n = 35) had an incomplete neurological deficit (Frankel B - D). Paraplegia was the most common motor deficit (42.9%). The lumbar spine was affected in 55.7% of cases. The most common CT scan finding was fracture of the vertebrae (30%) while the most reported MRI finding was disc herniation with contusion (38.5%). More than half (51.4%) of our patients were referred from peripheral health centers. The median arrival time was 48 h (IQR: 18-144) with 22.9% reporting after a week post-injury. Less than half (48.1%) benefited from surgery, and 41.4% of our population benefited from in-hospital rehabilitation. The median in-hospital delay time for surgery was 120 h (IQR: 66-192). While the median time between injury and surgery was 188 h (IQR: 144-347). The mortality rate was 5.7% (n = 4). Almost all (86.9%) of the patients developed complications and we had a 61.4% improvement in neurological status upon discharge. Being covered by health insurance was a predictor of improved neurological status (AOR = 15.04, 95%CI:2.90-78.20, P = 0.001) while being referred was a predictor of a stationary neurological status upon discharge (AOR = 0.12, 95%CI:0.03-0.52, P = 0.005). The average hospital stay was 20 days. We did not identify any predictors of lengthy hospital stay.

CONCLUSION

Road traffic accident is the most common etiology of TLSI. The arrival time to a neurosurgery specialized center after a traumatic injury, and the in-hospital delay time for surgery is high. Reduction of these delays, encouraging universal health insurance coverage, and improving on management to reduce complications would better the outcome of TLSI which is comparable with those in other studies.

Rehabilitation interventions for weaning from mechanical ventilation in patients with spinal cord injury: A systematic review

BACKGROUND

Despite the fact that weaning from mechanical ventilation (MV) is one of the main rehabilitation goals in patients with spinal cord injury (SCI), controversies are still open about the optimal rehabilitation approach.

OBJECTIVE

This systematic review aimed at characterizing the rehabilitation interventions currently available to optimize weaning from MV in SCI patients.

METHODS

On April 12nd, 2022, a systematic literature search was performed in PubMed, Scopus, Web of Science, Cochrane, and PEDro, identifying studies assessing MV patients with SCI undergoing pulmonary rehabilitation. The primary outcomes were weaning duration, MV duration, and weaning success rate. Secondary outcomes were pulmonary function, extubation or decannulation time, length of stay, and safety.

RESULTS

Out of 413 records, 14 studies were included (2 randomized controlled trials, 7 observational studies, and 5 case reports). Most of the studies assessed a comprehensive rehabilitation approach, including high tidal volume ventilation, positioning, mechanical lung recruitment maneuvers, secretion management strategies, respiratory muscle training, and electrical stimulation.

CONCLUSION

Our findings suggested that a comprehensive rehabilitation intervention might have a role in reducing MV duration in patients with SCI. Further studies are needed to better characterize the optimal rehabilitation strategies for enhancing functional recovery of patients with SCI.

Intermittent Hypoxia Differentially Regulates Adenosine Receptors in Phrenic Motor Neurons with Spinal Cord Injury

Cervical spinal cord injury (cSCI) impairs neural drive to the respiratory muscles, causing life- threatening complications such as respiratory insufficiency and diminished airway protection. Repetitive "low dose" acute intermittent hypoxia (AIH) is a promising strategy to restore motor function in people with chronic SCI. Conversely, "high dose" chronic intermittent hypoxia (CIH; ∼8 h/night), such as experienced during sleep apnea, causes pathology. Sleep apnea, spinal ischemia, hypoxia and neuroinflammation associated with cSCI increase extracellular adenosine concentrations and activate spinal adenosine receptors which in turn constrains the functional benefits of therapeutic AIH. Adenosine 1 and 2A receptors (A₁, A_2A) compete to determine net cAMP signaling and likely the tAIH efficacy with chronic cSCI. Since cSCI and intermittent hypoxia may regulate adenosine receptor expression in phrenic motor neurons, we tested the hypotheses that: 1) daily AIH (28 days) downregulates A_2A and upregulates A₁ receptor expression; 2) CIH (28 days) upregulates A_2A and downregulates A₁ receptor expression; and 3) cSCI alters the impact of CIH on adenosine receptor expression. Daily AIH had no effect on either adenosine receptor in intact or injured rats. However, CIH exerted complex effects depending on injury status. Whereas CIH increased A₁ receptor expression in intact (not injured) rats, it increased A_2A receptor expression in spinally injured (not intact) rats. The differential impact of CIH reinforces the concept that the injured spinal cord behaves in distinct ways from intact spinal cords, and that these differences should be considered in the design of experiments and/or new treatments for chronic cSCI.

Inspiratory Muscle Performance Is Related to Seated Balance Function in People With Spinal Cord Injury: An Observational Study

OBJECTIVE

To examine the relationship between inspiratory muscle performance (IMP) and functional sitting balance (FSB) in persons with chronic spinal cord injury (SCI). We hypothesized that a moderate correlation would be found between IMP and FSB and that individuals with better balance would have better IMP.

DESIGN

The SCI-specific modification of the Function in Sitting Test (FIST-SCI) measured FSB. The IMP measures included (1) maximal inspiratory pressure (MIP), (2) sustained MIP (SMIP), and (3) inspiratory duration. Upper extremity motor score (UEMS) and level of injury (LOI) were taken from International Standards for Neurological Classification of Spinal Cord Injury examinations. Spearman correlational analyses assessed relationships among these factors in the sample (N=37). Mann-Whitney U tests explored differences between 2 comparison group pairs (tetraplegia group [TG] vs paraplegia group [PG]; independent transfer group [ITG] vs assisted transfer group [ATG]). Regression analysis examined variables predictive of FSB in the TG.

SETTING

Research facility.

PARTICIPANTS

Volunteers with tetraplegia (n=21, American Spinal Injury Association Impairment Scale (AIS) A=8, B=7, C=6) and paraplegia (n=16, AIS A=9, B=4, C=3) (N=37).

INTERVENTION

Not applicable.

MAIN OUTCOME MEASURES

IMP, LOI, UEMS, FIST-SCI.

RESULTS

UEMS, MIP, SMIP, and LOI had moderate to high correlations with FIST-SCI scores (ρ=0.720 (P<.001), 0.480 (P=.003), 0.467 (P=.004), 0.527 (P=.001), respectively). UEMS, MIP, and FIST-SCI scores were higher in the PG and ITG than the TG and ATG, respectively (PG vs. TG P values=<.001, .008, .002, respectively, and ITG vs. ATG P values=<.001, .032, <.001, respectively). Further, SMIP and UEMS predicted FIST-SCI balance scores in the TG, accounting for 55% of total variance (P<.001) (FIST-SCI=11.88+0.03 [SMIP]+0.425 [UEMS]).

CONCLUSIONS

The relationship between IMP and balance appears preserved after SCI. FSB was predicted, in part, via UEMS and SMIP in the TG. Future research should focus on the effect of SCI-based breathing interventions on FSB.

Efficacy and toxicity of the DPCPX nanoconjugate drug study for the treatment of spinal cord injury in rats

Effects of the Adenosine A1 blockade using 8-cyclopentyl-1,3-diprophyxanthine (DPCPX) nanoconjugate on inducing recovery of the hemidiaphragm paralyzed by hemisection have been thoroughly examined previously; however, the toxicology of DPCPX nanoconjugate remains unknown. This research study investigates the therapeutic efficacy and toxicology of the nanoconjugate DPCPX in the cervical spinal cord injury (SCI) rat model. We hypothesized that a single injection of nanoconjugate DPCPX in the paralyzed left hemidiaphragm (LDH) of hemisected rats at the 2^nd cervical segment (C2Hx) would lead to the long-term recovery of LDH while showing minimal toxicity. Adult male rats underwent left C2Hx surgery and the diaphragms' baseline electromyography (EMG). Subsequently, rats were randomized into a control group, and four treated subgroups. Three subgroups received a single intradiaphragmatic dose of either 0.09, 0.15, 0.27 µg/kg, and one subgroup received 0.1 mg/kg of native DPCPX 2 times/day intravenous (i.v.) for 3 days (total 0.6 mg/kg). Rats were monitored for a total of 56 days. Compared to control, the treatment with nanoconjugate DPCPX at 0.09 µg/kg, 0.15 µg/kg, and 0.27 µg/kg doses elicited significant recovery of paralyzed LDH (i.e., 67% recovery at eight weeks) (p<0.05). DPCPX nanoconjugate treated rats had significant weight loss first two weeks but recovered significantly by day 56 (p<0.05). The levels of gold in the blood and body tissues were below the recommended levels. No sign of weakness, histology of tissue damage, or organ abnormality was observed. A single dose of DPCPX nanoconjugate can induce long-term diaphragm recovery after SCI without observed toxicity.

Noninvasive and invasive mechanical ventilation for neurologic disorders

Patients with acute neurologic injuries frequently require mechanical ventilation due to diminished airway protective reflexes, cardiopulmonary failure secondary to neurologic insults, or to facilitate gas exchange to precise targets. Mechanical ventilation enables tight control of oxygenation and carbon dioxide levels, enabling clinicians to modulate cerebral hemodynamics and intracranial pressure with the goal of minimizing secondary brain injury. In patients with acute spinal cord injuries, neuromuscular conditions, or diseases of the peripheral nerve, mechanical ventilation enables respiratory support under conditions of impending or established respiratory failure. Noninvasive ventilatory approaches may be carefully considered for certain disease conditions, including myasthenia gravis and amyotrophic lateral sclerosis, but may be inappropriate in patients with Guillain-Barré syndrome or when relevant contra-indications exist. With regard to discontinuing mechanical ventilation, considerable uncertainty persists about the best approach to wean patients, how to identify patients ready for extubation, and when to consider primary tracheostomy. Recent consensus guidelines highlight these and other knowledge gaps that are the focus of active research efforts. This chapter outlines important general principles to consider when initiating, titrating, and discontinuing mechanical ventilation in patients with acute neurologic injuries. Important disease-specific considerations are also reviewed where appropriate.

Sustained A1 Adenosine Receptor Antagonist Drug Release from Nanoparticles Functionalized by a Neural Tracing Protein

Respiratory dysfunction is a major cause of death in people with spinal cord injury (SCI). A remaining unsolved problem in treating SCI is the intolerable side effects of the drugs to patients. In a significant departure from conventional targeted nanotherapeutics to overcome the blood-brain barrier (BBB), this work pursues a drug-delivery approach that uses neural tracing retrograde transport proteins to bypass the BBB and deliver an adenosine A1 receptor antagonist drug, 1,3-dipropyl-8-cyclopentyl xanthine, exclusively to the respiratory motoneurons in the spinal cord and the brainstem. A single intradiaphragmatic injection at one thousandth of the native drug dosage induces prolonged respiratory recovery in a hemisection animal model. To translate the discovery into new treatments for respiratory dysfunction, we carry out this study to characterize the purity and quality of synthesis, stability, and drug-release properties of the neural tracing protein (wheat germ agglutinin chemically conjugated to horseradish peroxidase)-coupled nanoconjugate. We show that the batch-to-batch particle size and drug dosage variations are less than 10%. We evaluate the nanoconjugate size against the spatial constraints imposed by transsynaptic transport from pre to postsynaptic neurons. We determine that the nanoconjugate formulation is capable of sustained drug release lasting for days at physiologic pH, a prerequisite for long-distance transport of the drug from the diaphragm muscle to the brainstem. We model the drug-release profiles using a first-order reaction model and the Noyes-Whitney diffusion model. We confirm via biological electron microscopy that the nanoconjugate particles do not accumulate in the tissues at the injection site. We define the nanoconjugate storage conditions after monitoring the solution dispersion stability under various conditions for 4 months. This study supports further development of neural tracing protein-enabled nanotherapeutics for treating respiratory problems associated with SCI.

Risk Factors for Pulmonary Embolism in Patients with Paralysis and Deep Venous Thrombosis

Background. Venous thromboembolism is a frequent complication and an important cause of death in patients with paralysis. We aimed to investigate predictors of pulmonary embolism (PE) and the impact of PE on the survival of patients with paralysis in comparison to those with deep venous thrombosis or thrombophlebitis (DVT). Methods: Patients were selected by screening the German nationwide inpatient sample (2005–2017) for paralysis, and were stratified for venous thromboembolism (VTE) and the VTE-sub-entity PE (ICD-code I26). Impact of PE on mortality and predictors for PE were analyzed. Results: Overall, 7,873,769 hospitalizations of patients with paralysis were recorded in Germany 2005–2017, of whom 1.6% had VTE and 7.0% died. While annual hospitalizations increased (2005: 520,357 to 2017: 663,998) (β 12,421 (95% CI 10,807 to 14,034), p < 0.001), in-hospital mortality decreased from 7.5% to 6.7% (β −0.08% (95% CI −0.10% to −0.06%), p < 0.001). When focusing on 82,558 patients with paralysis hospitalized due to VTE (51.8% females; 58.3% aged ≥ 70 years) in 2005–2017, in-hospital mortality was significantly higher in patients with paralysis and PE than in those with DVT only (23.8% vs. 6.3%, p < 0.001). Cancer (OR 2.18 (95% CI 2.09–2.27), p < 0.001), heart failure (OR 1.83 (95% CI 1.76–1.91), p < 0.001), COPD (OR 1.63 (95% CI 1.53–1.72), p < 0.001) and obesity (OR 1.42 (95% CI 1.35–1.50), p < 0.001) were associated with PE. PE (OR 4.28 (95% CI 4.07–4.50), p < 0.001) was a strong predictor of in-hospital mortality. Conclusions: In Germany, annual hospitalizations of patients with paralysis increased in 2005–2017, in whom VTE and especially PE substantially affected in-hospital mortality. Cancer, heart failure, COPD, obesity and acute paraplegia were risk factors of PE.

Timely intubation with early prediction of respiratory exacerbation in acute traumatic cervical spinal cord injury

Background

Early routine intubation in motor-complete cervical spinal cord injury (CSCI) above the C5 level is a conventional protocol to prevent unexpected respiratory exacerbation (RE). However, in the context of recent advances in multidisciplinary respiratory management, the absolute indication for intubation in patients with CSCI based on initial neurologic assessment is controversial because of the drawbacks of intubation. This study aimed to redetermine the most important predictor of RE following CSCI after admission without routine intubation among patients admitted with motor-complete injury and/or injury above the C5 level to ensure timely intubation.

Methods

We performed a retrospective review of patients with acute traumatic CSCI admitted to our hospital without an initial routine intubation protocol from January 2013 to December 2017. CSCI patients who developed RE (defined as unexpected emergent intubation for respiratory resuscitation) were compared with those who did not. Baseline characteristics and severity of trauma data were collected. Univariate analyses were performed to compare treatment data and clinical outcomes between the two groups. Further, multivariate logistic regression was performed with clinically important independent variables: motor-complete injury, neurologic level above C5, atelectasis, and copious airway secretion (CAS).

Results

Among 58 patients with CSCI, 35 (60.3%) required post-injury intubation and 1 (1.7%) died during hospitalization. Thirteen (22.4%) had RE 3.5 days (mean) post-injury; 3 (37.5%) of eight patients with motor-complete CSCI above C5 developed RE. Eleven of the 27 (40.7%) patients with motor-complete injury and five of the 22 (22.7%) patients with neurologic injury above C5 required emergency intubation at RE. Three of the eight CSCI patients with both risk factors (motor-complete injury above C5) resulted in emergent RE intubation (37.5%). CAS was an independent predictor for RE (odds ratio 7.19, 95% confidence interval 1.48–42.72, P = 0.0144) in multivariate analyses.

Conclusion

Timely intubation post-CSCI based on close attention to CAS during the acute 3-day phase may prevent RE and reduce unnecessary invasive airway control even without immediate routine intubation in motor-complete injury above C5.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12873-021-00530-3.

Separation from mechanical ventilation and survival after spinal cord injury: a systematic review and meta-analysis

BACKGROUND

Prolonged need for mechanical ventilation greatly impacts life expectancy of patients after spinal cord injury (SCI). Weaning outcomes have never been systematically assessed. In this systematic review and meta-analysis, we aimed to investigate the probability of weaning success, duration of mechanical ventilation, mortality, and their predictors in mechanically ventilated patients with SCI.

METHODS

We searched six databases from inception until August 2021 for randomized-controlled trials and observational studies enrolling adult patients (≥ 16 years) with SCI from any cause requiring mechanical ventilation. Titles and abstracts were screened independently by two reviewers. Full texts of the identified articles were then assessed for eligibility. Data were extracted independently and in duplicate by pairs of authors, using a standardized data collection form. Synthetic results are reported as meta-analytic means and proportions, based on random effects models.

RESULTS

Thirty-nine studies (14,637 patients, mean age 43) were selected. Cervical lesions were predominant (12,717 patients had cervical lesions only, 1843 in association with other levels' lesions). Twenty-five studies were conducted in intensive care units (ICUs), 14 in rehabilitative settings. In ICU, the mean time from injury to hospitalization was 8 h [95% CI 7-9], mean duration of mechanical ventilation 27 days [20-34], probability of weaning success 63% [45-78] and mortality 8% [5-11]. Patients hospitalized in rehabilitation centres had a greater number of high-level lesions (C3 or above), were at 40 days [29-51] from injury and were ventilated for a mean of 97 days [65-128]; 82% [70-90] of them were successfully weaned, while mortality was 1% [0-19].

CONCLUSIONS

Although our study highlights the lack of uniform definition of weaning success, of clear factors associated with weaning outcomes, and of high-level evidence to guide optimal weaning in patients with SCI, it shows that around two-thirds of mechanically ventilated patients can be weaned in ICU after SCI. A substantial gain in weaning success can be obtained during rehabilitation, with additional duration of stay but minimal increase in mortality. The study is registered with PROSPERO (CRD42020156788).

Inspiratory Muscle Performance and Anthropometric Measures-Novel Assessments Related to Pulmonary Function in People with Spinal Cord Injury: A Pilot Study

OBJECTIVE

To investigate the feasibility and validity of using the novel axillary:umbilical (A:U) ratio and sustained maximal inspiratory pressure (SMIP) as supplementary measures in the assessment of respiratory function in people with spinal cord injury.

DESIGN

Pilot study with a single day of data collection. All measurements were taken with participants in their personal wheelchairs to best represent normal functioning and positioning for each individual.

SETTING

Research institution.

PARTICIPANTS

A convenience sample of 30 community dwelling volunteers with chronic spinal cord injury (C2-T12, American Spinal Injury Association Impairment Scale A-D) participated.

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

Participants underwent anthropometric measurements (trunk height, abdominal circumference, axillary circumference) and assessment of inspiratory muscle performance, incluidng maximal inspiratory pressure, SMIP, and inspiratory duration, as well as standard pulmonary function tests.

RESULTS

The A:U ratio and SMIP were recorded for all participants. The SMIP was significantly related to more respiratory performance measures than the maximal inspiratory pressure (P<.05) and the A:U ratio was significantly related to more respiratory performance measures than any other anthropometric measure (P<.05). Additionally, an A:U ratio cutoff point detected individuals with a peak expiratory flow ≥ 80% of their predicted value with a sensitivity and specificity of 85.7% and 91.3%, respectively (area under the curve: 0.92).

CONCLUSIONS

It is feasible to capture the A:U Ratio and SMIP in individuals with spinal cord injury. Further, the strong significant relationships of SMIP and the A:U ratio to respiratory performance measures suggests their clinical importance in the pulmonary assessment and risk stratification of people with chronic spinal cord injury.

Health inequalities and income for people with spinal cord injury. A comparison between and within countries

Income and health are related in a bi-directional manner, whereby level of income affects health and vice versa. People in poorer households tend to experience worse health status and higher mortality rates than people in wealthier households, and, at the same time, having poor health could restrict workability leading to less income. This gap exists in almost every country, and it is more pronounced in more unequal countries and in vulnerable populations, such as people experiencing disability. The goal of this paper is to estimate the health-income gap in people with a Spinal Cord Injury (SCI), which is a chronic health condition often associated with multiple comorbidities that leads to disability. As data on mortality is inexistent, to estimate the health-income gap for persons with SCI, this paper uses two health outcomes: the number of years a person has lived with the injury, and a comorbidity index. Data was obtained from the International Spinal Cord Injury survey (InSCI), which is the first worldwide survey on community-dwelling persons with SCI. To compare across countries, the health outcomes were adjusted through hierarchical models, accounting for country fixed-effects, individual characteristics such as age and gender, and injury characteristics (cause, type and degree). Our results suggest that for the years living with SCI, the gap varies from 1 to 6 years between the lowest and the highest income groups. The main driver of such a difference is the cause of injury, where injuries caused by work accidents showed the biggest gap. Similarly, for the comorbidity index, persons with SCI in poorer deciles reported significantly more comorbidities, forty times more, than people in richer deciles.

Electrical epidural stimulation of the cervical spinal cord: implications for spinal respiratory neuroplasticity after spinal cord injury

Traumatic cervical spinal cord injury (cSCI) can lead to damage of bulbospinal pathways to the respiratory motor nuclei and consequent life-threatening respiratory insufficiency due to respiratory muscle paralysis/paresis. Reports of electrical epidural stimulation (EES) of the lumbosacral spinal cord to enable locomotor function after SCI are encouraging, with some evidence of facilitating neural plasticity. Here, we detail the development and success of EES in recovering locomotor function, with consideration of stimulation parameters and safety measures to develop effective EES protocols. EES is just beginning to be applied in other motor, sensory, and autonomic systems; however, there has only been moderate success in preclinical studies aimed at improving breathing function after cSCI. Thus, we explore the rationale for applying EES to the cervical spinal cord, targeting the phrenic motor nucleus for the restoration of breathing. We also suggest cellular/molecular mechanisms by which EES may induce respiratory plasticity, including a brief examination of sex-related differences in these mechanisms. Finally, we suggest that more attention be paid to the effects of specific electrical parameters that have been used in the development of EES protocols and how that can impact the safety and efficacy for those receiving this therapy. Ultimately, we aim to inform readers about the potential benefits of EES in the phrenic motor system and encourage future studies in this area.

Mouthpiece Noninvasive Ventilation in a Patient With Traumatic Cervical Spinal Cord Injury: A Case Report

The use of noninvasive ventilation (NIV) has been associated with improved patient satisfaction and comfort compared to tracheostomy in patients who are ventilator dependent. We present a case of a young man who fell off a platform and sustained a traumatic third and fourth cervical vertebrae (C3/4) fracture dislocation with bilateral facet dislocation, in whom a trial of mouthpiece NIV was attempted. We discuss the issues surrounding this method of ventilation in ventilator-dependent patients.

Transcutaneous electrical diaphragmatic stimulation reduces the duration of invasive mechanical ventilation in patients with cervical spinal cord injury: retrospective case series

Study design

Retrospective case series.

Objectives

To compare individuals with cervical spinal cord injury (SCI) submitted to transcutaneous electrical diaphragmatic stimulation (TEDS) or a standard weaning protocol (SWP) according to the following variables: invasive mechanical ventilation (IMV) time, ventilator weaning time, intensive care unit (ICU) length of stay, and overall hospital length of stay.

Settings

Tertiary university hospital. Clinical Hospital of Campinas State University—UNICAMP—Campinas (SP), Brazil.

Methods

Retrospective case study investigating ICU patients submitted to tracheostomy due to cervical SCI at a tertiary university hospital (Clinical Hospital of Campinas State University, Brazil). Data were extracted from medical records of patients seen between January 2007 and December 2016. According to medical records, four patients were submitted to TEDS and six to a SWP. Provision of training to patients in the TEDS group was based on consensus medical decision, preference of the physical therapy team and availability of electrostimulation equipment in the ICU.

Results

Total IMV time in the TEDS and the SWP group was 33 ± 15 and 60 ± 22 days, respectively. Length of stay in ICU in the TEDS and the SWP group was 31 ± 18 and 63 ± 45 days, respectively.

Conclusion

TEDS appears to influence the duration of IMV as well as the length of stay in ICU. This physiotherapeutic intervention may be a potentially promising tool for treatment of patients with SCI. However, randomized clinical trials are warranted to support this assumption.

Updated Review: The Steroid Controversy for Management of Spinal Cord Injury

BACKGROUND

Acute spinal cord injury (ASCI) is a devastating event that can have a profound impact on the lives of patients and their families. While no definitive medical treatment exists, the role of methylprednisolone (MP) in the management of ASCI and other spinal cord pathologies has been investigated in depth; however, its use remains contentious. While MP initially showed promise in the efficacy of ASCI treatment, more recent studies have questioned its use citing numerous systemic adverse effects. Pharmacologic treatments in this area are poorly understood due to the scarcity of knowledge surrounding the pathophysiology and heterogeneity of patients presenting with these conditions. Despite these shortcomings and due to the lack of alternative treatment options, MP is still widely used by physicians.

METHODS

We review prior and current literature on the use of MP treatment for ASCI patients with a discussion of novel drug delivery systems that have demonstrated the potential to improve MP's bioavailability at the site of injury while minimizing systemic side effects. In addition, current views on the role of MP and dexamethasone in metastatic spinal cord compression and postoperative infection are reviewed.

RESULTS

While some data support benefits in the use of steroids on spinal cord pathology, extensive research suggests at best limited effects and an unresolvable risk/benefit problem.

CONCLUSIONS

At present, evidence regarding use of dexamethasone for MSCC is contentious, especially regarding dose regiments. Ultimately, further investigation into the use of steroids is required to determine its utility in treating patients with spinal cord pathology.

Autonomous control of ventilation through closed-loop adaptive respiratory pacing

Mechanical ventilation is the standard treatment when volitional breathing is insufficient, but drawbacks include muscle atrophy, alveolar damage, and reduced mobility. Respiratory pacing is an alternative approach using electrical stimulation-induced diaphragm contraction to ventilate the lung. Oxygenation and acid-base homeostasis are maintained by matching ventilation to metabolic needs; however, current pacing technology requires manual tuning and does not respond to dynamic user-specific metabolic demand, thus requiring re-tuning of stimulation parameters as physiological changes occur. Here, we describe respiratory pacing using a closed-loop adaptive controller that can self-adjust in real-time to meet metabolic needs. The controller uses an adaptive Pattern Generator Pattern Shaper (PG/PS) architecture that autonomously generates a desired ventilatory pattern in response to dynamic changes in arterial CO₂ levels and, based on a learning algorithm, modulates stimulation intensity and respiratory cycle duration to evoke this ventilatory pattern. In vivo experiments in rats with respiratory depression and in those with a paralyzed hemidiaphragm confirmed that the controller can adapt and control ventilation to ameliorate hypoventilation and restore normocapnia regardless of the cause of respiratory dysfunction. This novel closed-loop bioelectronic controller advances the state-of-art in respiratory pacing by demonstrating the ability to automatically personalize stimulation patterns and adapt to achieve adequate ventilation.

Acute traumatic quadriplegia: Predictors of in-hospital and six-month mortality

Background

Traumatic spinal cord injury is one of the most disastrous and devastating health burdens all over the world with a high mortality rate. The present study aimed to evaluate the predictors of in-hospital and six-month mortality in these patients.

Methods

The electronic medical records of 87 consecutive patients with acute complete traumatic quadriplegia were reviewed to extract clinical, radiological, and laboratory data. Simple and multiple logistic regression models were used to estimate crude and adjusted odds with 95% confidence interval (CI) ratios for the predictors of in-hospital mortality and six-month mortality.

Results

There were 48 males and the mean age was 38.67 ± 12.81; in-hospital and six-month mortality were 21.84% and 11.76%, respectively. Traffic road accidents (67.8%) and falls (12.6%) were the most common causes of injury. The univariate analysis demonstrated advanced age, level of injury, late surgery or no surgical intervention, the lack of methylprednisolone therapy, a higher Charlson comorbidity index, the Injury Severity Score, and the presence of respiratory failure or bradycardia on admission were predictors of in-hospital mortality ( p < 0.05). In the final multiple logistic regression model, the level of injury (OR = 0.02 (0.001,0.35), p = 0.008) and the presence of respiratory failure (OR = 2.37 (0.03,13.88), p = 0.024) were the only predictors of in-hospital mortality. The univariate model showed that the level of injury, respiratory failure on admission, and the Injury Severity Score were the predictors of six-month mortality; however, the level of injury was the only predictor of the six-month mortality (OR = 1.12 (0.99, 1.27), p = 0.028) according to the multiple logistic regression model.

Conclusions

Several factors could affect in-hospital and six-month mortality in patients with traumatic spinal cord injury. Our findings demonstrated the level of injury and respiratory failure on admission as independent predictors of in-hospital mortality in these patients. Furthermore, the level of injury was the only independent predictor of six-month mortality in the present study.

A case for inspiratory muscle training in SCI: potential role as a preventative tool in infectious respiratory diseases like COVID-19

INTRODUCTION

Respiratory complications (RC) are a leading cause of death after spinal cord injury (SCI) due to compromised immune function and respiratory muscle weakness. Thus, individuals with SCI are at high risk of developing COVID-19 related RC. Results of a SCI clinical trial showed a supervised respiratory muscle training (RMT) program decreased risk of developing RC. The feasibility of conducting unsupervised RMT is not well documented. Four publications (n = 117) were identified in which unsupervised RMT was performed. Significant improvements in respiratory outcomes were reported in two studies: Maximal Inspiratory and Expiratory Pressure (MIP40% and MEP25%, respectively), Peak Expiratory Flow (PEF9%), seated and supine Forced Vital Capacity (FVC23% and 26%, respectively), and Peak Cough Flow (28%). This review and case report will attempt to show that an inspiratory muscle training (IMT) home exercise program (HEP) is feasible and may prepare the respiratory system for RC associated with COVID-19 in patients with SCI.

CASE PRESENTATION

A 23-year-old with tetraplegia (P1), history of mechanical ventilation, and hospitalization for RC, completed 27 IMT HEP sessions in one month. MIP and sustained MIP (SMIP) increased from baseline by 28% and 26.5%, respectively. Expiratory volumes and rates also improved (FVC, FEV1, and PEF: 11.7%, 8.3%, and 14.2%, respectively).

DISCUSSION

The effects of COVID-19 on patients with SCI remains inconclusive, but recent literature and the results of this case suggest that unsupervised IMT is feasible and may limit the severity of RC in patients with SCI who contract COVID-19.

1-Year Mortality and Surgery Incidence in Older US Adults with Cervical Spine Fracture

BACKGROUND

Traumatic cervical spinal cord injuries (SCIs) can be lethal and are especially dangerous for older adults. Falls from standing and risk factors for a cervical fracture and spinal cord injury increase with age. This study estimates the 1-year mortality for patients with a cervical fracture and resultant SCI and compares the mortality rate with that from an isolated cervical fracture.

METHODS

We performed a retrospective cohort study of U.S. Medicare patients older than 65 years of age. International Classification of Diseases (ICD)-9 codes were used to identify patients with a cervical fracture without SCI and patients with a cervical fracture with SCI between 2007 and 2014. Our primary outcome was 1-year mortality cumulative incidence rate; our secondary outcome was the cumulative incidence rate of surgical intervention. Propensity weighted analysis was performed to balance covariates between the groups.

RESULTS

The SCI cohort had a 1-year mortality of 36.5%, compared with 31.1% in patients with an isolated cervical fracture (risk difference 5.4% (2.9%-7.9%)). Patients with an SCI were also more likely to undergo surgical intervention compared with those without a SCI (23.1% and 10.3%, respectively; risk difference 12.8% (10.8%-14.9%)).

CONCLUSIONS

Using well-adjusted population-level data in older adults, this study estimates the 1-year mortality after SCI in older adults to be 36.5%. The mortality after a cervical fracture with SCI was 5 percentage points higher than in patients without SCI, and this difference is smaller than one might expect, likely representing the frailty of this population and unmeasured covariates.

Restoring Ventilatory Control Using an Adaptive Bioelectronic System

Ventilatory pacing by electrical stimulation of the phrenic nerve or of the diaphragm has been shown to enhance quality of life compared to mechanical ventilation. However, commercially available ventilatory pacing devices require initial manual specification of stimulation parameters and frequent adjustment to achieve and maintain suitable ventilation over long periods of time. Here, we have developed an adaptive, closed-loop, neuromorphic, pattern-shaping controller capable of automatically determining a suitable stimulation pattern and adapting it to maintain a desired breath-volume profile on a breath-by-breath basis. The system adapts the pattern of stimulation parameters based on the error between the measured volume sampled every 40 ms and a desired breath volume profile. In vivo studies in anesthetized male Sprague-Dawley rats without and with spinal cord injury by spinal hemisection at C2 indicated that the controller was capable of automatically adapting stimulation parameters to attain a desired volume profile. Despite diaphragm hemiparesis, the controller was able to achieve a desired volume in the injured animals that did not differ from the tidal volume observed before injury (p = 0.39). Closed-loop adaptive pacing partially mitigated hypoventilation as indicated by reduction of end-tidal CO₂ values during pacing. The closed-loop controller was developed and parametrized in a computational testbed before in vivo assessment. This bioelectronic technology could serve as an individualized and autonomous respiratory pacing approach for support or recovery from ventilatory deficiency.

[Diaphragmatic pacemaker dysfunction and utility of diaphragmatic ultrasonography]

Patients with spinal cord injuries above the C5 vertebrae have a high risk of respiratory complications, and complete spinal cord injures can require support with mechanical ventilation. In selected patients, implantation of a diaphragmatic pacemaker offers the possibility of breathing without mechanical support and reduces respiratory complications, increasing the patient's independence. Ultrasonography is a simple and non-invasive technique that may be useful in the differential diagnosis of thoracic diseases. We present the case of a patient with a traumatic cervical spinal cord injury, who underwent diaphragmatic pacemaker implantation. The use of ultrasound allowed rapid and reliable diagnosis of device malfunction. M-mode diaphragmatic ultrasonography is a simple and non-invasive technique that can be incorporated into routine clinical practice to diagnose diaphragm movement disorders.

Therapeutic systemic hypothermia for a pediatric patient with an isolated cervical spinal cord injury

Context: While uncommon, spinal cord injuries most frequently occur in adolescent and young adult males. Established treatment options are limited and focused on supportive care. Therapeutic systemic hypothermia is an emerging experimental treatment currently undergoing clinical trials in adults.Findings: Here we report a case of a 13-year-old male with an American Spinal Injury Association Impairment Scale grade C traumatic cervical spinal cord injury treated with 48 hours of therapeutic systemic hypothermia who made a complete neurological recovery. To our knowledge, this is the youngest such case report.Clinical relevance: This case suggests that consideration should be given to including pediatric patients in future clinical trials of therapeutic hypothermia for spinal cord injury.

Predictive Values of Magnetic Resonance Imaging Features for Tracheostomy in Traumatic Cervical Spinal Cord Injury

Objective

To evaluate the magnetic resonance (MR) imaging features that have a statistically significant association with the need for a tracheostomy in patients with cervical spinal cord injury (SCI) during the acute stage of injury.

Methods

This study retrospectively reviewed the clinical data of 130 patients with cervical SCI. We analyzed the factors believed to increase the risk of requiring a tracheostomy, including the severity of SCI, the level of injury as determined by radiological assessment, three quantitative MR imaging parameters, and eleven qualitative MR imaging parameters.

Results

Significant differences between the non-tracheostomy and tracheostomy groups were determined by the following five factors on multivariate analysis : complete SCI (p=0.007), the radiological level of C5 and above (p=0.038), maximum canal compromise (MCC) (p=0.010), lesion length (p=0.022), and osteophyte formation (p=0.015). For the MCC, the cut-off value was 46%, and the risk of requiring a tracheostomy was three times higher at an interval between 50–60% and ten times higher between 60–70%. For lesion length, the cut-off value was 20 mm, and the risk of requiring a tracheostomy was two times higher at an interval between 20–30 mm and fourteen times higher between 40–50 mm.

Conclusion

The American Spinal Injury Association grade A, a radiological injury level of C5 and above, an MCC ≥50%, a lesion length ≥20 mm, and osteophyte formation at the level of injury were considered to be predictive values for requiring tracheostomy intervention in patients with cervical SCI.

Risks factors of mechanical ventilation in acute traumatic cervical spinal cord injured patients

STUDY DESIGN

Descriptive retrospective study.

OBJECTIVES

To analyze risk factors associated with mechanical ventilation (MV) in cases of acute traumatic Cervical Spinal Cord Injury (tCSCI).

SETTING

Unidad de Lesionados Medulares, Complejo Hospitalario Universitario A Coruña, in Galicia (Spain).

METHODS

The study included patients with tCSCI who were hospitalized between January 2010 and December 2014. The following variables were analyzed: age, gender, etiology, neurological level, ASIA (American Spinal Injury Association) grade, associated injuries, injury severity score (ISS), ASIA motor score (AMS) at admission and mortality.

RESULTS

A total of 146 patients met the study's inclusion criteria. The majority were men (74.7%) with mean age of 62.6 (s.d. ± 18.8) years. Sixty patients (41.1%) required MV. Mean age of ventilated vs. non-ventilated patients was 57.3 vs. 65.7. Men were more likely to require MV than women, ASIA grades A and B were also more likely to need MV than grades C and D, as well as patients with associated injuries. The AMS of patients receiving MV was lower than that of those who did not require MV (20.1 vs. 54.3). Moreover, the ISS was higher in patients receiving MV (31.2 vs. 13.4). An AMS ≤ 37 and an ISS ≥ 13 increased the risk of requiring MV by a factor of 11.98 and 7.28, respectively.

CONCLUSIONS

Isolated factors associated with a greater risk of MV in tCSCI were: age, gender, ASIA grade, ISS and AMS. However, the only factor with a significant discriminatory ability to determine the need for MV was the AMS at admission.

Evidence-based respiratory management strategies required to prevent complications and improve outcome in acute spinal cord injury patients

Spinal injuries without neurological damage have little effects on respiratory function unless associated with injury to the chest wall. Early verticalisation or mobilisation of these patients is safe and likely to improve vital capacity. Spinal injury with cord damage has a profound effect on the mechanics of respiration and on respiratory function particularly in cervical cord injuries. Around 40% of spinal cord injuries occur in the cervical spine, a trend that is steadily increasing, with respiratory causes being responsible for death in over 20% of individuals. Loss of lung volumes and relative hypoxemia contribute to global hypoxaemia, exacerbating cord ischaemia in the acute period. Respiratory compromise results in the loss of muscle strength generation capacity and reduced lung volumes and in particular vital capacity, of up to 70%, ineffective cough and secretion clearance abilities; reductions in both lung and chest wall compliance and an additional oxygen cost of breathing due to changes in respiratory mechanics, with obstructive sleep apnoea evident in over 50% of acute tetraplegics. While some countries have specialist spinal centres to manage such catastrophic trauma with a demonstrable improvement in health outcomes attributed to their contribution, many individuals are initially admitted to local hospitals where healthcare professionals are less likely to fully appreciate the significant and continued vulnerabilities of such individuals. This article aims to provide a basic understanding of the causes and identification of the main principles of the respiratory management strategies required to maintain pulmonary health for cervical spinal cord injury patients during the initial and early post trauma phase.

Electrical Neuromodulation of the Respiratory System After Spinal Cord Injury

Spinal cord injury (SCI) is a complex and devastating condition characterized by disruption of descending, ascending, and intrinsic spinal circuitry resulting in chronic neurologic deficits. In addition to limb and trunk sensorimotor deficits, SCI can impair autonomic neurocircuitry such as the motor networks that support respiration and cough. High cervical SCI can cause complete respiratory paralysis, and even lower cervical or thoracic lesions commonly result in partial respiratory impairment. Although electrophrenic respiration can restore ventilator-independent breathing in select candidates, only a small subset of affected individuals can benefit from this technology at this moment. Over the past decades, spinal cord stimulation has shown promise for augmentation and recovery of neurologic function including motor control, cough, and breathing. The present review discusses the challenges and potentials of spinal cord stimulation for restoring respiratory function by overcoming some of the limitations of conventional respiratory functional electrical stimulation systems.

Update on traumatic acute spinal cord injury. Part 2

The aim of treatment in acute traumatic spinal cord injury is to preserve residual neurologic function, avoid secondary injury, and restore spinal alignment and stability. In this second part of the review, we describe the management of spinal cord injury focusing on issues related to short-term respiratory management, where the preservation of diaphragmatic function is a priority, with prediction of the duration of mechanical ventilation and the need for tracheostomy. Surgical assessment of spinal injuries based on updated criteria is discussed, taking into account that although the type of intervention depends on the surgical team, nowadays treatment should afford early spinal decompression and stabilization. Within a comprehensive strategy in spinal cord injury, it is essential to identify and properly treat patient anxiety and pain associated to spinal cord injury, as well as to prevent and ensure the early diagnosis of complications secondary to spinal cord injury (thromboembolic disease, gastrointestinal and urinary disorders, pressure ulcers).

Respiratory problems and management in people with spinal cord injury

Spinal cord injury (SCI) is characterised by profound respiratory compromise secondary to the level of loss of motor, sensory and autonomic control associated with the injury. This review aims to detail these anatomical and physiological changes after SCI, and outline their impact on respiratory function. Injury-related impairments in strength substantially alter pulmonary mechanics, which in turn affect respiratory management and care. Options for treatments must therefore be considered in light of these limitations.

KEY POINTS

Respiratory impairment following spinal cord injury (SCI) is more severe in high cervical injuries, and is characterised by low lung volumes and a weak cough secondary to respiratory muscle weakness.Autonomic dysfunction and early-onset sleep disordered breathing compound this respiratory compromise.The mainstays of management following acute high cervical SCI are tracheostomy and ventilation, with noninvasive ventilation and assisted coughing techniques being important in lower cervical and thoracic level injuries.Prompt investigation to ascertain the extent of the SCI and associated injuries, and appropriate subsequent management are important to improve outcomes.

EDUCATIONAL AIMS

To describe the anatomical and physiological changes after SCI and their impact on respiratory function.To describe the changes in respiratory mechanics seen in cervical SCI and how these changes affect treatments.To discuss the relationship between injury level and respiratory compromise following SCI, and describe those at increased risk of respiratory complications.To present the current treatment options available and their supporting evidence.

Gene therapy and respiratory neuroplasticity

Breathing is a life-sustaining behavior that in mammals is accomplished by activation of dedicated muscles responsible for inspiratory and expiratory forces acting on the lung and chest wall. Motor control is exerted by specialized pools of motoneurons in the medulla and spinal cord innervated by projections from multiple centers primarily in the brainstem that act in concert to generate both the rhythm and pattern of ventilation. Perturbations that prevent the accomplishment of the full range of motor behaviors by respiratory muscles commonly result in significant morbidity and increased mortality. Recent developments in gene therapy and novel targeting strategies have contributed to deeper understanding of the organization of respiratory motor systems. Gene therapy has received widespread attention and substantial progress has been made in recent years with the advent of improved tools for vector design. Genes can be delivered via a variety of plasmids, synthetic or viral vectors and cell therapies. In recent years, adeno-associated viruses (AAV) have become one of the most commonly used vector systems, primarily because of the extensive characterization conducted to date and the versatility in targeting strategies. Recent studies highlight the power of using AAV to selectively and effectively transduce respiratory motoneurons and muscle fibers with promising therapeutic effects. This brief review summarizes current evidence for the use of gene therapy in respiratory disorders with a primary focus on interventions that address motor control and neuroplasticity, including regeneration, in the respiratory system.

Respiratory Function Under Intrathecal Baclofen Therapy in Patients With Spastic Tetraplegia

OBJECTIVES

Intrathecal baclofen (ITB) therapy is an effective treatment for patients with severe spasticity. However, the effect of ITB therapy on respiratory function has not been reported in detail. In this study we quantitatively analyzed the effects of ITB on the respiratory function of patients with spastic tetraplegia.

METHODS

We retrospectively reviewed 23 patients who were administrated ITB therapy from January 2009 to December 2012. Six of these 23 patients, who had spastic tetraplegia and were able to undergo spirometric testing, were included this study. The spasticity derived from cervical spinal cord injury in four patients and cerebral palsy (CP) in two patients. Patients' Ashworth Scale scores and spirometer measurements obtained before and 1-6 months after the start of ITB therapy were evaluated and compared.

RESULTS

Before ITB therapy, %FVC of all six patients was below 80%, and a restrictive respiratory disorder was diagnosed in five patients and a combined respiratory disorder in one patient. Ashworth Scale scores for both the lower and upper extremities improved significantly with ITB therapy. Forced vital capacity (FVC), %FVC, and forced expiratory volume at one sec also improved significantly with ITB therapy.

CONCLUSIONS

Respiratory disorders were indeed present in our SCI and CP patients with spastic tetraplegia, and the respiratory function of these patients improved with ITB therapy. Our results suggest that ITB therapy is safe and efficacious in patients with spastic tetraplegia and respiratory dysfunction.

Impact of mechanical ventilation on the pathophysiology of progressive acute lung injury

The earliest description of what is now known as the acute respiratory distress syndrome (ARDS) was a highly lethal double pneumonia. Ashbaugh and colleagues (Ashbaugh DG, Bigelow DB, Petty TL, Levine BE Lancet 2: 319-323, 1967) correctly identified the disease as ARDS in 1967. Their initial study showing the positive effect of mechanical ventilation with positive end-expiratory pressure (PEEP) on ARDS mortality was dampened when it was discovered that improperly used mechanical ventilation can cause a secondary ventilator-induced lung injury (VILI), thereby greatly exacerbating ARDS mortality. This Synthesis Report will review the pathophysiology of ARDS and VILI from a mechanical stress-strain perspective. Although inflammation is also an important component of VILI pathology, it is secondary to the mechanical damage caused by excessive strain. The mechanical breath will be deconstructed to show that multiple parameters that comprise the breath-airway pressure, flows, volumes, and the duration during which they are applied to each breath-are critical to lung injury and protection. Specifically, the mechanisms by which a properly set mechanical breath can reduce the development of excessive fluid flux and pulmonary edema, which are a hallmark of ARDS pathology, are reviewed. Using our knowledge of how multiple parameters in the mechanical breath affect lung physiology, the optimal combination of pressures, volumes, flows, and durations that should offer maximum lung protection are postulated.

Abdominal Functional Electrical Stimulation to Assist Ventilator Weaning in Acute Tetraplegia: A Cohort Study

Background

Severe impairment of the major respiratory muscles resulting from tetraplegia reduces respiratory function, causing many people with tetraplegia to require mechanical ventilation during the acute stage of injury. Abdominal Functional Electrical Stimulation (AFES) can improve respiratory function in non-ventilated patients with sub-acute and chronic tetraplegia. The aim of this study was to investigate the clinical feasibility of using an AFES training program to improve respiratory function and assist ventilator weaning in acute tetraplegia.

Methods

AFES was applied for between 20 and 40 minutes per day, five times per week on four alternate weeks, with 10 acute ventilator dependent tetraplegic participants. Each participant was matched retrospectively with a ventilator dependent tetraplegic control, based on injury level, age and sex. Tidal Volume (V_T) and Vital Capacity (V_C) were measured weekly, with weaning progress compared to the controls.

Results

Compliance to training sessions was 96.7%. Stimulated V_T was significantly greater than unstimulated V_T. V_T and V_C increased throughout the study, with mean V_C increasing significantly (V_T: 6.2 mL/kg to 7.8 mL/kg V_C: 12.6 mL/kg to 18.7 mL/kg). Intervention participants weaned from mechanical ventilation on average 11 (sd: ± 23) days faster than their matched controls.

Conclusion

The results of this study indicate that AFES is a clinically feasible technique for acute ventilator dependent tetraplegic patients and that this intervention may improve respiratory function and enable faster weaning from mechanical ventilation.

Trial Registration

ClinicalTrials.gov NCT02200393

Cervical spine clearance in obtunded patients after blunt traumatic injury: a systematic review

BACKGROUND

Cervical spine clearance protocols are controversial for unconscious patients after blunt traumatic injury and negative findings on computed tomography (CT).

PURPOSE

To review evidence about the utility of different cervical spine clearance protocols in excluding significant cervical spine injury after negative CT results in obtunded adults with blunt traumatic injury.

DATA SOURCES

MEDLINE, EMBASE, CINAHL, Google Scholar, and the Cochrane Library were searched from January 2000 through November 2014.

STUDY SELECTION

English-language studies that examined patients with negative CT results having confirmatory routine testing with magnetic resonance imaging (MRI), dynamic radiography, or clinical examination and that reported outcome measures of missed cervical spine injury, need for operative stabilization, or prolonged use of cervical collars.

DATA EXTRACTION

Independent reviewers evaluated the quality of studies and abstracted the data according to a predefined protocol.

DATA SYNTHESIS

Of 28 observational studies (3627 patients) that met eligibility criteria, 7 were prospective studies (1686 patients) with low risk of bias and well-interpreted, high-quality CT scans. These 7 studies showed that 0% of significant injuries were missed after negative CT results. The overall studies using confirmatory routine testing with MRI showed incidence rates of 0% to 1.5% for cervical spine instability (16 studies; 1799 patients), 0% to 7.3% for need for operative fixation (17 studies; 1555 patients), and 0% to 29.5% for prolonged collar use (16 studies; 1453 patients).

LIMITATIONS

Most studies were retrospective. Approaches to management of soft tissue changes with collars varied markedly.

CONCLUSION

Cervical spine clearance in obtunded adults after blunt traumatic injury with negative results from a well-interpreted, high-quality CT scan is probably a safe and efficient practice.

PRIMARY FUNDING SOURCE

None.

Alcohol intoxication and its effects on traumatic spinal cord injury outcomes

There are sparse data regarding the impact of alcohol on in-hospital complications associated with traumatic spinal cord injuries (TSCIs). We set out to quantify the impact of alcohol on TSCI outcomes and its influence on health care cost and utilization. The National Trauma Data Bank (NTDB) Research Data Set version 7.2 (2000-2006) was utilized to gather data between 2007 and 2009. We extracted cases of TSCI (International Classification of Diseases, Ninth Revision, Clinical Modification codes 806.xx) without concurrent traumatic brain injury. Outcomes of interest were mortality, length of stay (LOS), intensive care unit (ICU) days, ventilator days, and complications. Continuous outcomes such as LOS, ICU days, and ventilator days were analyzed using linear regression. Risk-adjusted analysis of risk factors for mortality and complication rates were performed using multiple logistic regression. Of the 10,611 persons identified in the NTDB, alcohol was present in approximately one fifth of all cases (20.76%). A majority of TSCI patients were young (mean age, 39 years) Caucasian (65.07%) males (75.93%). Blunt injury was the most common mechanism of injury. The presence of alcohol did not significantly affect mortality or neurological complications. Alcohol in the blood was associated with extended LOS, longer ICU stays, more days spent ventilated, and increased risk of all-type complications. Further, there was a statistically significant association with the presence alcohol and increased risk for pulmonary, pneumonia, deep vein thrombosis and pulmonary embolism, urinary tract infection, and ulcer/skin complications. Alcohol intoxication is associated with increased in-hospital morbidity. The significant association with in-hospital complications increases health resource utilization after spinal cord injury.

Reprint of "Drawing breath without the command of effectors: the control of respiration following spinal cord injury"

The maintenance of blood gas and pH homeostasis is essential to life. As such breathing, and the mechanisms which control ventilation, must be tightly regulated yet highly plastic and dynamic. However, injury to the spinal cord prevents the medullary areas which control respiration from connecting to respiratory effectors and feedback mechanisms below the level of the lesion. This trauma typically leads to severe and permanent functional deficits in the respiratory motor system. However, endogenous mechanisms of plasticity occur following spinal cord injury to facilitate respiration and help recover pulmonary ventilation. These mechanisms include the activation of spared or latent pathways, endogenous sprouting or synaptogenesis, and the possible formation of new respiratory control centres. Acting in combination, these processes provide a means to facilitate respiratory support following spinal cord trauma. However, they are by no means sufficient to return pulmonary function to pre-injury levels. A major challenge in the study of spinal cord injury is to understand and enhance the systems of endogenous plasticity which arise to facilitate respiration to mediate effective treatments for pulmonary dysfunction.

Persistent hypoalbuminemia is a predictor of outcome in cervical spinal cord injury

BACKGROUND CONTEXT

Hypoalbuminemia is associated with increased morbidity and mortality in various clinical settings and several major diseases. Albumin has multiple physiologic properties that could be beneficial in central nervous system injury.

PURPOSE

We sought to determine if albumin is associated with patient outcome after cervical spinal cord injury by conducting a retrospective analysis.

STUDY DESIGN/SETTING

A retrospective study of cervical spinal cord injury (CSCI) patients was conducted to investigate if serum albumin levels and other characteristics influence outcome (mechanical ventilation and death).

PATIENT SAMPLE

A total of 178 consecutive patients were included in the present study.

OUTCOME MEASURES

Demographic data were recorded, including age, gender, smoking history, time from injury to admission, severity of neurologic injury, neurologic level of lesion, mechanism of neurologic injury, Glasgow Coma Score, vitals in the Orthopedic Department, the occurrence of early surgical intervention (48 hours after injury), and daily serum albumin levels.

METHODS

No funds were received in support of this work. No specific conflicts of interest were involved in this article. Serum albumin levels and other characteristics known to influence outcome were included in univariate statistical analyses and the multiple logistic regression model to analyze the relationship with mechanical ventilation and death after cervical injury.

RESULTS

Approximately 41.0% (73/178) of patients had complete spinal cord injury (ASIA A), 36.5% (65/178) of patients required mechanical ventilation, and 8.4% (15/178) of patients died within the first month after injury. Albumin remained lower than 30 g/L for a period of time (≥5 days) in patients with an unfavorable outcome (patients requiring mechanical ventilation or who had died). Multiple logistic regression analysis identified age (>50 years), persistent hypoalbuminemia (<30 g/L and ≥5 days), C5 and above neurologic injury, and ASIA A as predictors for mechanical ventilation. In addition, persistent hypoalbuminemia, ASIA A, and C4 and above neurologic injury were significantly associated with death.

CONCLUSION

Similar to the ASIA scale and neurologic level, persistent hypoalbuminemia seems to be an independent predictor of outcome in patients with CSCI. Thus, a randomized trial assessing albumin in the treatment of cervical spinal cord injury is warranted.

Magnetic resonance imaging predictors for respiratory failure after cervical spinal cord injury

BACKGROUND

Patients after cervical spinal cord injury (CSCI) may experience ventilator-dependent respiratory failure during the acute hospitalization period. The aim of the study is to identify imaging factors that predict respiratory failure after acute CSCI.

MATERIALS AND METHODS

We enrolled 108 patients diagnosed with CSCI in 4 years. The definition of respiratory failure consisted of the requirement of a definitive airway and the assistance of mechanical ventilation. Objective neurological function was determined using the classification of the American Spinal Injury Association (ASIA). We evaluated the characteristics of magnetic resonance imaging (MRI) of the cervical spine.

RESULTS

Respiratory failure occurred in 8 (7.40%) of 108 CSCI patients. The ASIA classification of the 108 patients were A (6), B (3), C (60), D (27), and E (12), and the 8 respiratory failure patients were A (3), B (1), and C (4). Seven of 8 patients with respiratory failure and 78 of 100 patients without respiratory failure had a neurological level of C5 or above by the ASIA standards (p=1.000). The imaging level of injury at C3 by MRI was identified in 5 of 8 patients that developed respiratory failure and more frequent than injury at the lower cervical levels (p<0.001). The presence of spinal cord edema was another predictor of respiratory failure (p=0.009).

CONCLUSION

MRI can accurately localize CSCI and identify those patients at risk of respiratory failure. Imaging level of injury at C3 and presence of spinal cord edema are both predictors. To prevent secondary cord injury from prolonged hypoxia and facilitate pulmonary care, definitive airways should be established early in high risk patients.

Mechanical ventilation weaning and extubation after spinal cord injury: a Western Trauma Association multicenter study

BACKGROUND

Respiratory failure after acute spinal cord injury (SCI) is well recognized, but data defining which patients need long-term ventilator support and criteria for weaning and extubation are lacking. We hypothesized that many patients with SCI, even those with cervical SCI, can be successfully managed without long-term mechanical ventilation and its associated morbidity.

METHODS

Under the auspices of the Western Trauma Association Multi-Center Trials Group, a retrospective study of patients with SCI at 14 major trauma centers was conducted. Comprehensive injury, demographic, and outcome data on patients with acute SCI were compiled. The primary outcome variable was the need for mechanical ventilation at discharge. Secondary outcomes included the use of tracheostomy and development of acute lung injury and ventilator-associated pneumonia.

RESULTS

A total of 360 patients had SCI requiring mechanical ventilation. Sixteen patients were excluded for death within the first 2 days of hospitalization. Of the 344 patients included, 222 (64.5%) had cervical SCI. Notably, 62.6% of the patients with cervical SCI were ventilator free by discharge. One hundred forty-nine patients (43.3%) underwent tracheostomy, and 53.7% of them were successfully weaned from the ventilator, compared with an 85.6% success rate among those with no tracheostomy (p < 0.05). Patients who underwent tracheostomy had significantly higher rates of ventilator-associated pneumonia (61.1% vs. 20.5%, p < 0.05) and acute lung injury (12.8% vs. 3.6%, p < 0.05) and fewer ventilator-free days (1 vs. 24 p < 0.05). When controlled for injury severity, thoracic injury, and respiratory comorbidities, tracheostomy after cervical SCI was an independent predictor of ventilator dependence with an associated 14-fold higher likelihood of prolonged mechanical ventilation (odds ratio, 14.1; 95% confidence interval, 2.78-71.67; p < 0.05).

CONCLUSION

While many patients with SCI require short-term mechanical ventilation, the majority can be successfully weaned before discharge. In patients with SCI, tracheostomy is associated with major morbidity, and its use, especially among patients with cervical SCI, deserves further study.

LEVEL OF EVIDENCE

Prognostic study, level III.

Predictors of clinical complications in patients with spinomedullary injury

Objective: To analyze individuals with spinal cord injury who developed secondary clinical complications, and the variables that can influence the prognosis. Methods: A prospective study of 321 patients with spinal cord injury. The variables were collected: age, sex, cause of the accident, anatomical distribution, neurological status, associated injuries, in-hospital complications, and mortality only in patients who developed complications. Results: A total of 72 patients were analyzed (85% male) with a mean age of 44.72±19.19 years. The individuals with spinal cord injury who developed clinical complications were mostly male, over 50 years of age, and the main cause was accidental falls. These patients had longer hospitalization times and a higher risk of progressing to death. Pneumonia was the main clinical complication. With regard to the variables that can influence the prognosis of these patients, it was observed that spinal cord injury to the cervical segment with syndromic quadriplegia, and neurological status ASIA-A, have a higher risk of developing pneumonia, the most common complication, as well as increased mortality. Conclusion: Clinical complications secondary to spinal cord injury are influenced by demographic factors, as well as characteristics of the injury contributing to an increase in mortality.