Long-term survival of persons ventilator dependent after spinal cord injury

Longitudinal changes in employment, health, participation, and quality-of-life and the relationships with long-term survival after spinal cord injury

STUDY DESIGN

Cohort study.

OBJECTIVE

To identify five-year longitudinal changes in employment, health, participation, and quality-of-life outcomes (QOL) among participants with chronic spinal cord injury (SCI) and to compare the amount of change in these outcomes between those surviving and those not surviving until follow-up.

METHODS

Participants were 1157 individuals from the SCI Longitudinal Aging Study, who have completed at least two self-report assessments separated by five-year intervals. The main outcome measures were 13 indicators related to employment, health, participation, and QOL/psychosocial indicators. Survival status measured at follow-up.

RESULTS

Those who survived to follow up had a history indicating a greater likelihood of employment, better health, participation, and QOL/psychosocial indicators. Among survivors, longitudinal declines were limited to the percent employed and participation indicators, whereas those deceased by follow-up had significant undesirable changes in employment, participation, health, and QOL/psychosocial indicators. More specifically, compared to the survivors, those deceased by follow-up experienced a greater increase in hospitalizations, decreases in nights away from home, and declines in global satisfaction over the five-year interval.

CONCLUSIONS

Longitudinal declines in employment and some aspects of participation are common among long-term survivors and may be part of the natural course of outcomes after SCI. However, more dramatic increases in hospitalizations, fewer nights away from home, and declining satisfaction may be red flags for declining longevity.

Diaphragm stimulation elicits phrenic afferent-induced neuromuscular plasticity

We hypothesized that activation of phrenic afferents induces diaphragm motor plasticity. In anesthetized and spontaneously breathing rats we delivered 40 Hz, low threshold (twitch and 1.5X twitch threshold), inspiratory-triggered stimulation to the left hemidiaphragm for 30 min to activate ipsilateral phrenic afferents. Diaphragm amplitude ipsilateral and contralateral to stimulation were increased for 60 min following both currents compared to time controls not receiving stimulation. Diaphragm stimulation was repeated in laminectomy controls or following a unilateral C3-C6 dorsal rhizotomy to eliminate phrenic afferent volleys. Laminectomy controls expressed neuromuscular plasticity post-stimulation. In contrast, ipsilateral and contralateral diaphragm amplitude following dorsal rhizotomy was lower than laminectomy controls and no different than time controls, suggesting diaphragm motor plasticity was not induced post-rhizotomy. Our results indicate that diaphragm stimulation induces a novel form of plasticity in the phrenic motor system which requires phrenic afferent activation. Respiratory motor plasticity elicited by diaphragm stimulation may have value as a therapeutic strategy to improve diaphragm output in neuromuscular conditions.

Life Satisfaction Trend and Mortality After Traumatic Spinal Cord Injury: A Cohort Study

Background

Individuals with traumatic spinal cord injuries (SCIs) have lower subjective well-being and diminished longevity, yet there is a lack of research on how life satisfaction and changes in life satisfaction relate to longevity.

Objectives

To identify the relationships between survival status and life satisfaction and its changing trend over a 10-year period.

Methods

Data were taken from the SCI Longitudinal Aging Study. A cohort study of 676 adult participants with SCI completed three assessments separated by 5-year intervals. We applied the survival analyses by using person-year logistic regression models.

Results

There were 135 participants (20%) who were deceased by the end of 2019. After controlling for demographic and injury factors, life satisfaction was significantly related to survival. In the final model, having an upward trend of life satisfaction was significantly associated with lower odds of mortality, whereas a downward trend in life satisfaction was not significant.

Conclusion

Our findings demonstrate the importance of current life satisfaction and having a trend toward improving satisfaction to survival. The findings indicated the importance of psychosocial adaptation to life quality and longevity after SCI.

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.

Systemic inflammation after spinal cord injury: A review of biological evidence, related health risks, and potential therapies

Individuals with chronic traumatic spinal cord injury (SCI) develop progressive multi-system health problems that result in clinical illness and disability. Systemic inflammation is associated with many of the common medical complications and acquired diseases that accompany chronic SCI, suggesting that it contributes to a number of comorbid pathological conditions. However, many of the mechanisms that promote persistent systemic inflammation and its consequences remain ill-defined. This review describes the significant biological factors that contribute to systemic inflammation, major organ systems affected, health risks, and the potential treatment strategies. We aim to highlight the need for a better understanding of inflammatory processes, and to establish appropriate strategies to address inflammation in SCI.

Social participation as a mediator of the relationships of socioeconomic factors and longevity after traumatic spinal cord injury

STUDY DESIGN

Cohort study.

OBJECTIVE

Previous research has indicated that socioeconomic factors affect longevity after traumatic spinal cord injury (SCI). Our purpose was to evaluate whether social participation mediates the relationship between socioeconomic factors and survival status after SCI.

SETTING

Medical university in the southeastern United States.

METHODS

Participants (N = 1540) met the following inclusion criteria: traumatic SCI of at least 1-year duration, minimum of 18 years of age, and having residual impairment from SCI. The main outcome measures were a) survival status as of December 31, 2019, identified by the National Death Index (NDI) search, b) socioeconomic status (SES), measured by education, employment status, and family income, and c) participation, measured by marital/relationship status, hours out of bed per day, days leaving home per week, and nights away home during the past year.

RESULTS

Thirty nine percent of participants (n = 602) were decreased by the end of 2019. Socioeconomic factors were associated with longevity controlling for demographic, injury characteristics, and health status. However, the association of SES with longevity was mediated by three social participation mobility indicators (hours out of bed, days out of house, and nights away from home), such that SES was no longer significantly related to longevity after inclusion of the participation variables.

CONCLUSIONS

Although socioeconomic factors are related to longevity, their relationship appears to be mediated by social participation mobility indicators. Intervention studies are needed to address the modifiable factors that may promote longevity, including promoting an active lifestyle.

Prospective analysis of a surgical algorithm to achieve ventilator weaning in cervical tetraplegia

Objectives: Chronic ventilator dependency in cervical tetraplegia is associated with substantial morbidity. When non-invasive weaning methods have failed the primary surgical treatment is diaphragm pacing. Phrenic nerve integrity and diaphragm motor units are requirements for effective pacing but may need to be restored for successful weaning. A surgical algorithm that includes: 1. Diaphragm pacing, 2. Phrenic nerve reconstruction, and 3. Diaphragm muscle replacement, may provide the capability of reducing or reversing ventilator dependency in virtually all cervical tetraplegics.Design: Prospective case series.Setting: A university-based hospital from 2015 to 2019.Participants: Ten patients with ventilator-dependent cervical tetraplegia.Interventions: I. Pacemaker alone, II. Pacemaker + phrenic nerve reconstruction, or III. Pacemaker + diaphragm muscle replacement.Outcome measures: Time from surgery to observed reduction in ventilator requirements (↓VR), ventilatory needs as of most recent follow-up [no change (NC), partial weaning (PW, 1-12 h/day), or complete weaning (CW, >12 h/day)], and complications.Results: Both patients in Group I achieved CW at 6-month follow-up. Two patients in Group II achieved CW, and in another two patients PW was achieved, at 1.5-2-year follow-up. The remaining two patients are NC at 6 and 8-month follow-up, respectively. In group III, both patients achieved PW at 2-year follow-up. Complications included mucous plugging (n = 1) and pacemaker malfunction requiring revision (n = 3).Conclusion: Although more investigation is necessary, phrenic nerve reconstruction or diaphragm muscle replacement performed (when indicated) with pacemaker implantation may allow virtually all ventilator-dependent cervical tetraplegics to partially or completely wean.

Diaphragm Pacing in Spinal Cord Injury Can Significantly Decrease Mechanical Ventilation in Multicenter Prospective Evaluation

BACKGROUND

Cervical spinal cord injury (SCI) can lead to dependence on mechanical ventilation (MV) with significant morbidity and mortality. The diaphragm pacing system (DPS) was developed as an alternative to MV.

METHODS

We conducted a prospective single arm study of DPS in MV dependent patients with high SCI and intact phrenic nerves. Following device acclimation, pacing effectiveness to provide ventilation was evaluated. The primary endpoint was the number who could use DPS to breathe for four continuous hours without MV. Secondary endpoints included the number of patients that could use DPS 24 hours/day free of MV and the ability of DPS to maintain clinically acceptable tidal volume (Vt). In addition, we conducted a meta-analysis that included the prospective study along with data from four recently published studies to evaluate DPS hourly use.

RESULTS

Fifty-three patients were implanted in the prospective study. Most were male (77.4%) with a median time from injury to treatment of 28.3 (IQR 12.1, 83.3) months. Four- and 24-hour use occurred in 96.2% (95%CI - 87.0%, 99.5%) and 58.5% (95% CI - 44.1%, 74.9%), respectively. Four and 24-hour results in the meta-analysis cohort (n=196) exhibited similar results 92.2% (95% CI - 82.6%,96.7%) and 52.7% (95% CI - 36.2%,68.6%) using DPS for four and 24 hours, respectively. DPS use significantly exceeded the calculated basal tidal volume requirements by a mean of 48.4% (95% CI - 37.0, 59.9%; p<0.001).

CONCLUSIONS

This study demonstrates that in most ventilator-dependent patients, diaphragm pacing can effectively supplement or completely replace the need for MV and support basal metabolic requirements.

Factors Associated With Ventilator Weaning Success and Failure in People With Spinal Cord Injury in an Acute Inpatient Rehabilitation Setting: A Retrospective Study

Objectives

To evaluate baseline characteristics, describe pulmonary outcomes, and identify weaning predictors for people with acute traumatic spinal cord injury (SCI) who are dependent on mechanical ventilation at admission to acute inpatient rehabilitation (AIR).

Methods

The retrospective study was conducted at an AIR facility in the United States. It included 91 adults with acute traumatic SCI from 2015 to 2019 who were dependent on mechanical ventilation.

Results

People who successfully weaned (85%) had fewer days from time of SCI to AIR admission (22 vs. 30, p = .04), higher vital capacity at admission to AIR (12 vs. 3 mL/kg predicted body weight [PBW]; p < .001), and lower (caudal) neurological injury level (p < .001) compared to those who failed weaning. The risk of pneumonia was higher in people who failed weaning compared to those who were weaned successfully (risk ratio, 5.5; 95% confidence interval [95% CI], 2.3-13). Receiver operating characteristics (ROC) curves suggest a vital capacity cutoff of 5.8 mL/kg PBW could predict weaning. The vital capacity of ≥ 5.8 mL/kg PBW is associated with 109 times higher odds (95% CI, 11-1041; p < .001) of weaning than vital capacity below that threshold.

Conclusion

In this retrospective study, there was an increased risk of pneumonia in people with SCI who failed weaning at discharge from AIR. Vital capacity was a better predictor of weaning from mechanical ventilation compared to the neurological level of injury, with a cutoff of 5.8 mL/kg PBW predictive of weaning success. Further research is needed on this critical topic.

Cause of Death Trends Among Persons With Spinal Cord Injury in the United States: 1960-2017

OBJECTIVE

To identify trends in causes of death after spinal cord injury (SCI) that could enhance understanding of why life expectancy after SCI has not improved in the last 3 decades.

DESIGN

Cohort study.

SETTING

Twenty-nine SCI Model Systems and 3 Shriners Hospitals.

PARTICIPANTS

Individuals with traumatic SCI (N=49,266) enrolled in the SCI Collaborative Survival Study Database between 1973 and 2017.

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

Age-standardized cause-specific SCI mortality rates and 95% confidence intervals were calculated for 5 time intervals (1960-1979, 1980-1989, 1990-1999, 2000-2009, and 2010-2017).

RESULTS

A total of 17,249 deaths occurred in 797,226 person-years of follow-up. Since 2010, the highest mortality rate was for respiratory diseases, followed by heart disease, cancer, infective and parasitic diseases (primarily septicemia), and unintentional injuries. Mortality rates for respiratory diseases, cancer, stroke, urinary diseases, and digestive diseases, initially decreased significantly but remained relatively stable since 1980, whereas essentially no progress occurred for infective and parasitic diseases. Mortality rates for heart disease, pulmonary embolus, and suicide decreased significantly throughout the entire study period, but were offset by increases in mortality rates for endocrine (primarily diabetes), nutritional, and metabolic diseases, as well as unintentional injuries. From 2010 to 2017, the overall age-standardized mortality rate was 3 times higher for individuals with SCI than the general population, ranging from 27% higher for cancer to 9 times higher for infective and parasitic diseases.

CONCLUSION

Improving life expectancy after SCI will require: (1) reducing mortality rates from respiratory diseases and septicemia that have remained high, (2) reversing current trends in diabetes and unintentional injury deaths, and (3) continuing to reduce mortality from heart disease and other leading causes.

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).

Supplementary Information

The online version contains supplementary material available at 10.1186/s13613-021-00938-x.

Diaphragm Pacing in Patients with Spinal Cord Injury: A European Experience

BACKGROUND

Patients with high spinal cord injury (SCI) are unable to breathe on their own and require mechanical ventilation (MV). The long-term use of MV is associated with increased morbidity and mortality. In patients with intact phrenic nerve function, patients can be partially or completely removed from MV by directly stimulating the diaphragm motor points with a diaphragm pacing system (DPS).

OBJECTIVES

We describe our multicenter European experience using DPS in SCI patients who required MV.

METHODS

We conducted a retrospective study of patients who were evaluated for the implantation of DPS. Patients evaluated for DPS who met the prospectively defined criteria of being at least 1 year of age, and having cervical injury resulting in a complete or partial dependency on MV were included. Patients who received DPS implants were followed for up to 1 year for device usage and safety.

RESULTS

Across 3 centers, 47 patients with high SCI were evaluated for DPS, and 34 were implanted. Twenty-one patients had 12 months of follow-up data with a median DPS use of 15 h/day (interquartile range 4, 24). Eight patients (38.1%) achieved complete MV weaning using DPS 24 h/day. Two DPS-related complications were surgical device revision and a wire eruption. No other major complications were associated with DPS use.

CONCLUSIONS

Diaphragm pacing represents an attractive alternative stand-alone treatment or adjunctive therapy compared to MV in patients with high SCI. After a period of acclimation, the patients were able to reduce the daily use of MV, and many could be completely removed from MV.

Respiratory morbidity and mortality of traumatic cervical spinal cord injury at a level I trauma center in India

STUDY DESIGN

Descriptive retrospective.

OBJECTIVES

To evaluate the burden of respiratory morbidity in terms of ventilator dependence (VD) days and length of stay in neurotrauma ICU (NICU) and hospital, and to determine mortality in patients with traumatic cervical spinal cord injury (CSCI) in a low middle-income country (LMIC).

SETTING

Jai Prakash Narayan Apex Trauma Center (JPNATC), All India Institute of Medical Sciences (AIIMS), New Delhi, India.

METHODS

A total of 135 patients admitted with CSCI in the NICU between January 2017 to December 2018 were screened. Information regarding age, gender, American Spinal Injury Association (ASIA) impairment scale (AIS), level of injury, duration of VD, length of NICU, hospital stay, and outcome in terms of mortality or discharge from the hospital were obtained from the medical records.

RESULTS

A total of 106 CSCI patients were analyzed. The mean (SD) age of patients was 40 (±16) years and male: female ratio was 5:1. The duration of VD, duration of NICU, and hospital stay was a median of 8 days (IQR 1127), 6 days (IQR 1118), and 15 days (IQR 3127) respectively. Mortality was 19% (20/106). The mortality was significantly associated with poorer AIS score, VD, and duration of ICU and hospital stay. All patients were discharged to home only after they became ventilator-free.

CONCLUSIONS

The ventilator burden, hospital stay, and mortality are high in patients with CSCI in LMICs. Poor AIS scores, prolonged VD, ICU and hospital stay are associated with mortality. There is a need for comprehensive CSCI rehabilitation programs in LMICs to improve outcome.

Comparison of wire and disc electrodes to electrically activate the inspiratory muscles in dogs

OBJECTIVE

To compare the effectiveness of wire versus disc electrodes to activate the inspiratory muscles via high frequency spinal cord stimulation.

DESIGN

Animal study.

SETTING

Research laboratory.

ANIMALS

Dogs (n = 5) INTERVENTIONS: In separate trials, spinal cord stimulation (SCS) was applied via disc (DE) and two parallel wire electrodes (WE) on the ventral epidural space at the T2-T3 spinal region.

MAIN OUTCOME MEASURE(S)

Airway pressure (P) and inspired volume (V) generation following stimulation with DE and WE were compared. Given our previous success with (DE), outcome variables with this electrode were used as our gold standard to which all comparisons were made.

RESULTS

Two configurations of WE using monopolar stimulation (MS) resulted in P and V that were similar to those generated with MS with DE. For example, MS with parallel WE connected together to function as a common cathode (Y-connection) and a 2-channel system (separate cathodes with a remote ground), resulted in P that were 91 ± 6 and 92 ± 4%, respectively, of those achieved with DE (NS for both). Bipolar stimulation with parallel WE using a Y-connection and with a 2-channel system, resulted in P that were 96 ± 4 and 94 ± 4%, of the P achieved with DE (NS for both).

CONCLUSION(S)

These results suggest that specific configurations of WE, which can be placed via minimally invasive techniques, provide comparable activation of the inspiratory muscles compared to DE and may be a useful technique to restore ventilatory support in persons with spinal cord injury.

Is autonomic dysreflexia a cause of respiratory dysfunction after spinal cord injury?

INTRODUCTION

Spinal cord injury (SCI) often leads to impairment of the respiratory system. In fact, respiratory insufficiency is a significant cause of mortality and morbidity following SCI, related to the extent and level of the neurologic injury and its effects on the respiratory muscles (reduction in respiratory muscle strength and fatigue due to a reduction in inspiratory capacity, atelectasis and ineffective coughing). Less commonly recalled is the fact that autonomic dysreflexia (AD) is the result of parasympathetic imbalance. However, AD results from a massive, unrestrained outpouring of norepinephrine from the peripheral sympathetic ganglia. More accurately, the vagal (parasympathetic) response to this sympathetic discharge may have been responsible for the respiratory changes reported. This is not described in medical literature, although breathing difficulty is named as a common symptom and sign. The objective of this report is to describe a clinical case for the first time, that of T4 AIS (American spinal injury association impairment scale) A in which AD leads to acute respiratory insufficiency.

CASE REPORT

A patient with prior history of spinal cord injury, T4 AIS A, was admitted to the Inpatient Unit to improve her respiratory function and autonomy and to discontinue the ventilation maintained after an episode of pneumonia. The patient developed AD during the rehabilitation programme, namely during hamstring stretching exercises. Besides persistent hypertension, cutaneous rash, hyperhidrosis and light-headedness, the patient was diagnosed with acute respiratory insufficiency, with desaturation and hypercapnia. The patient fully recovered, in terms of the signs and symptoms of AD, with the cessation of noxious stimulation and oxygen administration.

DISCUSSION

To date, the association between AD and acute respiratory insufficiency has not been described in spinal cord injury or rehabilitation literature. This case draws attention for the first time to the possibility that respiratory insufficiency is one of the signs associated with episodes of AD and highlights the need to look at this possibility.

Clinical introduction and benefits of non-invasive ventilation for above C3 cervical spinal cord injury

Study design: Retrospective study.Objectives: To determine the best time to introduce non-invasive ventilation (NIV), clinical effectiveness of NIV, and complications of long-term use of NIV in patients with high-level cervical spinal cord injuries (CSCI).Setting: Public Hospital, Japan.Methods: The subjects were 14 tracheostomy ventilator-dependent patients, with above C3 spinal lesions, and American Spinal Cord Injury Association Impairment Scale A (ASIA A). They were referred to our clinic between 2005 and 2010 for switching mechanical ventilation support system from tracheostomy ventilation to NIV. Respiratory function tests were measured before and after NIV. Patients who were successfully switched to NIV were interviewed two years later and asked about their health and social status.Results: Eleven patients were successfully switched to NIV. The success rate of switching to NIV within 1 year was also high (P < 0.05). NIV improved the vital capacity of C2 ASIA A and C1 ASIA A patients with adequate respiratory accessory muscle strength sufficient to expand the chest wall. The time on ventilator-free spontaneous breathing increased or did not deteriorate after NIV. Three C1 ASIA A patients with insufficient muscle strength to expand the thorax mastered glossopharyngeal breathing and enjoyed a short ventilator-free time. All patients who were successfully switched to NIV lived in the community. Two patients developed minor complications after discharge and two died later for unrelated causes.Conclusion: Ventilator-dependent patients should be switched to NIV within 1 year of injury. Long-term NIV can improve respiratory function and clinical outcome.

Spinal cord injury and gut microbiota: A review

After spinal cord injury (SCI), intestinal dysfunction has a serious impact on physical and mental health, quality of life, and social participation. Recent data from rodent and human studies indicated that SCI causes gut dysbiosis. Remodeling gut microbiota could be beneficial for the recovery of intestinal function and motor function after SCI. However, few studies have explored SCI with focus on the gut microbiota and "microbiota-gut-brain" axis. In this review, the complications following SCI, including intestinal dysfunction, anxiety and depression, metabolic disorders, and neuropathic pain, are directly or indirectly related to gut dysbiosis, which may be mediated by "gut-brain" interactions. Furthermore, we discuss the research strategies that can be beneficial in this regard, including germ-free animals, fecal microbiota transplantation, probiotics, phages, and brain imaging techniques. The current microbial research has shifted from descriptive to mechanismal perspective, and future research using new technologies may further demonstrate the pathophysiological mechanism of association of SCI with gut microbiota, elucidate the mode of interaction of gut microbiota and hosts, and help develop personalized microbiota-targeted therapies and drugs based on microbiota or corresponding metabolites.

Respiratory complications during initial rehabilitation and survival following spinal cord injury in Sweden: a retrospective study

Study design

Retrospective study.

Objectives

To determine prevalence of respiratory complications in individuals with spinal cord injury (SCI) during the initial rehabilitation at the spinal cord injury unit (SCU) and to describe the subsequent effect on mortality.

Setting

The SCU at the university hospital in Gothenburg, Sweden.

Methods

We reviewed the medical charts of newly injured persons with SCI who were admitted to the SCU between 1/1/2010 and 12/31/2014. Outcome measures were time to death, length of stay, occurrence of respiratory complications, and the use of breathing aids.

Results

A total of 136 consecutive individuals were included; 53% with cervical SCI and 20% with lower SCI suffered from one or several respiratory complications during their initial rehabilitation in the SCU. At follow-up, 10/1/2018, 20% of the individuals were deceased. The most common cause of death was related to respiratory insufficiency. The individuals with respiratory complications during the initial rehabilitation in the SCU had particularly shortened survival compared with those without. The relative risk (RR) of dying if the person suffered from any respiratory complications during their initial rehabilitation in the SCU was 2.1 times higher than for those with no respiratory complications (RR, 2.1; 95% CI, 1.1–3.9).

Conclusions

Having respiratory complications at the SCU provides preliminary data to support the claim that respiratory complications predict premature mortality. Early diagnosis and prophylactic measures seem to be necessary to mitigate the adverse consequences of serious respiratory problems.

Motor and Sensory Function as a Predictor of Respiratory Function Associated With Ventilator Weaning After High Cervical Cord Injury

Objective

To analyze the respiratory function of high cervical cord injury according to ventilator dependence and to examine the correlations between diaphragm movement found on fluoroscopy and sensory and motor functions.

Methods

A total of 67 patients with high cervical spinal cord injury (SCI), admitted to our hospital were enrolled in the study. One rehabilitation physician performed sensory and motor examinations on all patients while each patient was in the supine position on the American Spinal Injury Association (ASIA) standard. In addition, fluoroscopic diaphragm movement studies and bedside spirometry were performed.

Results

Bedside spirometry and diaphragm fluoroscopic tests were analyzed according to ventilator dependence. Forced vital capacity and maximal inspiratory pressure were significantly higher in the ventilator weaned group. Natural breathing during the fluoroscopic diaphragm examinations and ventilator weaning showed statistical significance with the movement on the right, while deep breathing showed statistical significance with the movement on both sides. Deep breathing movement has correlation with the C5 key muscle. Diaphragm movement has correlation with right C3 and bilateral C4 sensory functions.

Conclusion

The present expansion study showed that, through simple bedside physical examinations, rehabilitation physicians could relatively easily predict diaphragm movement and respiratory function recovery, which showed significance with ventilator weaning in patients with high cervical SCI.

Reinnervation of the diaphragm by the inferior laryngeal nerve to the phrenic nerve in ventilator-dependent tetraplegic patients with C3-5 damage

The aim of this study was to evaluate the feasibility of unilateral diaphragmatic reinnervation in humans by the inferior laryngeal nerve. This pilot study included chronically ventilated tetraplegic patients with destruction of phrenic nerve motoneurons. Five patients were included. They all had a high level of tetraplegia, with phrenic nerve motor neuron destruction. They were highly dependent on ventilation, without any possibility of weaning. They did not have other chronic pathologies, especially laryngeal disease. They all had diaphragmatic explorations to diagnose the destruction of the motoneurons of the phrenic nerves and nasoendoscopy to be sure that they did not have laryngeal or pharyngeal disease. Then, surgical anastomosis of the right phrenic nerve was performed with the inferior laryngeal nerve, by a cervical approach. A laryngeal reinnervation was performed at the same time, using the ansa hypoglossi. One patient was excluded because of a functional phrenic nerve and one patient died 6 months after the surgery of a cardiac arrest. The remaining three patients were evaluated after the anastomosis every 6 months. They did not present any swallowing or vocal alterations. In these three patients, the diaphragmatic explorations showed that there was a recovery of the diaphragmatic electromyogram of the right and left hemidiaphragms after 1 year. Two patients had surgical diaphragmatic explorations for diaphragmatic pacing 18-24 months after the reinnervation with excellent results. At 36 months, none of the patients could restore their automatic ventilation. In conclusion, this study demonstrated that diaphragmatic reinnervation by the inferior laryngeal nerve is effective, without any vocal or swallowing complications.

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.

[Long-term survival after severe trauma]

Long-term survival after severe trauma is rarely addressed in German trauma journals although knowledge of life expectancy and identification of factors contributing to increased mortality are important for lifetime care management, development of service models, and targeting health promotion and prevention interventions. As reliable data in Germany are lacking, we compiled data mainly from the USA and Australia to describe life expectancy, risk factors, and predictors of outcome in patients experiencing traumatic spinal cord injury, traumatic brain injury, and polytrauma. Two years after trauma, life expectancy in all three categories was significantly lower than that of the general population. It depends strongly on severity of disability, age, and gender and is quantifiable. Whereas improvements in medical care have led to a marked decline in short-term mortality, surprisingly long-term survival in severe trauma has not changed over the past 30 years. Therefore, there is need to intensify long-term trauma patient care and to find new strategies to limit primary damage.

Long-term survival after traumatic spinal cord injury: a 70-year British study

STUDY DESIGN

Retrospective and prospective observational.

OBJECTIVES

Analyse long-term survival after traumatic spinal cord injury (SCI) in Great Britain over the 70-year study period, identify mortality risk factors and estimate current life expectancy.

SETTING

Two spinal centres in Great Britain.

METHODS

The sample consisted of patients with traumatic SCI injured 1943-2010 who survived the first year post-injury, had residual neurological deficit on discharge and were British residents. Life expectancy and trends over time were estimated by neurological grouping, age and gender, using logistic regression of person-years of follow-up combined with standard life table calculations.

RESULTS

For the 5483 cases of traumatic SCI the mean age at injury was 35.1 years, 79.7% were male, 31.1% had tetraplegia AIS/Frankel ABC, 41.2% paraplegia ABC,and 27.7% functionally incomplete lesion (all Ds). On 31 December 2014, 54% were still alive, 42.3% had died and 3.7% were lost to follow-up. Estimated life expectancies improved significantly between the 1950s and 1980s, plateaued during the next two decades, before slightly improving again since 2010. The estimated current life expectancy, compared with the general British population, ranged from 18.1 to 88.4% depending on the ventilator dependency, level and completeness of injury, age and gender.

CONCLUSIONS

Life expectancy after SCI improved significantly between the 1950s and 1980s, plateaued during the 1990s and 2000s, before slightly improving again since 2010, but still remains well below that of the general British population.

SPONSORSHIP

Buckinghamshire Healthcare NHS Trust Charitable Spinal Fund and Ann Masson Legacy for Spinal Research Fund, UK.

Anxiety and Depression in Patients with Traumatic Spinal Cord Injury: A Nationwide Population-Based Cohort Study

BACKGROUND

Traumatic spinal cord injury (tSCI) may involve new-onset anxiety and depression post-discharge. However, long-term population-based studies have lacked access to follow-up conditions in terms of new-onset anxiety and depression. The objective of this study was to estimate the long-term risk of new-onset anxiety and depression post-discharge.

METHODS

The Longitudinal Health Insurance Database 2000 (LHID2000) from Taiwan's National Health Insurance Research Database was used in this study. Individuals with tSCI were identified using the International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) diagnostic codes of 806 and 952 from 1999-2008. The comparison cohort (other health conditions group) was randomly selected from the LHID2000 and was 1:1 matched by age, sex, index year, and comorbidities to reduce the selection bias. All study participants were retrospectively followed for a maximum of 3 years until the end of follow-up, death, or new-onset anxiety (ICD-9-CM: 309.2-309.4) or depression (ICD-9-CM: 296.2, 296.5, 296.82, 300.4, 309.0-309.1, and 311). Persons who were issued a catastrophic illness card for tSCI were categorized as having a severe level of SCI (Injury Severity Score [ISS] ≥16). Poisson regression was used to estimate the incidence rate ratios of anxiety or depression between patients with tSCI and other health conditions. The relative risk of anxiety or depression was estimated using a Cox regression analysis, which was adjusted for potential confounding factors.

RESULTS

Univariate analyses showed that the tSCI patients (n = 3556) had a 1.33 times greater incidence of new-onset anxiety or depression (95% confidence interval [CI]: 1.12-1.57) compared to the other health conditions group (n = 3556). After adjusting for potential risk factors, the tSCI patients had a significant 1.29-fold increased risk of anxiety or depression compared to the group with other health conditions (95% CI: 1.09-1.53). Individuals with tSCI, including patients who were under the age of 35, patients who were males, patients who had a low income, and patients without a Charlson Comorbidity Index score, all had a higher long-term risk of anxiety or depression than the other health conditions group (IRRs: 1.84, 1.63, 1.29, and 1.39, respectively). For all tSCI patients, those with an Injury Severity Score (ISS) ≥16 had an almost 2-fold higher risk of anxiety or depression (adjusted Hazard Ratio: 1.85; 95% CI: 1.17-2.92) compared to those with ISS <16.

CONCLUSIONS

Our findings indicated that tSCI patients have a high risk of anxiety or depression post-discharge, especially among the younger tSCI patients (age <50 years), compared with the other health conditions group. This information could help physicians understand the long-term risk of new-onset anxiety or depression in tSCI patients post-discharge.

Long-Term Mechanical Ventilation

Although precise numbers are difficult to obtain, the population of patients receiving long-term ventilation has increased over the last 20 years, and includes patients with chronic lung diseases, neuromuscular diseases, spinal cord injury, and children with complex disorders. This article reviews the equipment and logistics involved with ventilation outside of the hospital. Discussed are common locations for long-term ventilation, airway and secretion management, and many of the potential challenges faced by individuals on long-term ventilation.

No-fault compensation for ventilator-dependent children: a reasonable settlement value for lifetime attendant care

Severe neurological outcomes sustained in childhood often result in lifetime health care needs that are beyond the financial means of most families. When severe neurological deficits are alleged to have resulted from professional negligence, relief may be sought through litigation; however, the American tort system often yields inconsistent results or no compensation for patients. We sought to identify a reasonable, objective, and data-based monetary range for a no-fault compensation system with high- and low-financial limits for those with severe neurological deficits. Based on documented life expectancies and attendant care cost studies, the data analysis indicates a no-fault settlement payment ranging from US$479,712.24 to $3,098,504.16, reasonably ensures care and services for life.

The relationship of life expectancy to the development and valuation of life care plans

BACKGROUND

A life care plan often analyzes needs up to a person's life expectancy. Expected present value of necessary funding for such a plan is likewise based on the fixed survival time. If a client should live beyond or die before the life expectancy, a shortfall or excess of funding may seem inevitable. The life table, of which life expectancy is a summary measure, clarifies these issues.

OBJECTIVES

We explain life expectancy and how it is used in tort litigation, economic calculations, and life care planning. We examine the life table, of which life expectancy is one output. We illustrate how a life table provides age-specific probabilities of death and survival, life expectancies, and median survival times, and other information and that every life expectancy must be associated with a life table. We consider the implications for life care planners, forensic economists, and others.

CONCLUSIONS

Life expectancy is a summary of more detailed information provided in a life table. The full life table provides better information for planning purposes. Whether life expectancy or a full life table should be used in developing and valuing a life care plan is not well understood. A multi-disciplinary approach may help clarify these issues.

Surgery for pressure ulcers in spinal cord-injured patients following a structured treatment programme: a 10-year follow-up

With the aim to improve the outcomes for spinal cord-injured patients undergoing surgery for pressure ulcers, a structured treatment programme regulating pre- and postoperative care and rehabilitation was introduced in 2002 in Stockholm. Fifty-one consecutive patients operated on between 2002 and 2007 were included in a 10-year follow-up to evaluate the programme regarding initial healing results and long-term ulcer and health status. At one month postoperatively, 49 out of 51 (96%) patients were completely healed. Five patients (5/44, 11%) developed recurrent or new ulcers within 3 years of surgery. Two patients were re-operated on (2/44, 5%). Between 3 and 10 years after surgery, 9 patients (9/33, 27%) had a history of recurrent ulcers, and 6 (6/33, 18%) had a history of new ulcers, a total of 15 patients (15/33, 45%). Of these, three needed re-operation (3/33, 9 %). The health status values using a visual analogue rating scale were 70 (median) at 3 and 10 years compared with 30 (median) preoperatively. The good initial healing, the low ulcer recurrence rate and the raise in health status indicate the value of a structured treatment programme, especially for the first few postoperative years.

Cervical spinal cord injury exacerbates ventilator-induced diaphragm dysfunction

Cervical spinal cord injury (SCI) can dramatically impair diaphragm muscle function and often necessitates mechanical ventilation (MV) to maintain adequate pulmonary gas exchange. MV is a life-saving intervention. However, prolonged MV results in atrophy and impaired function of the diaphragm. Since cervical SCI can also trigger diaphragm atrophy, it may create preconditions that exacerbate ventilator-induced diaphragm dysfunction (VIDD). Currently, no drug therapy or clinical standard of care exists to prevent or minimize diaphragm dysfunction following SCI. Therefore, we first tested the hypothesis that initiating MV acutely after cervical SCI will exacerbate VIDD and enhance proteolytic activation in the diaphragm to a greater extent than either condition alone. Rats underwent controlled MV for 12 h following acute (∼24 h) cervical spinal hemisection injury at C2 (SCI). Diaphragm tissue was then harvested for comprehensive functional and molecular analyses. Second, we determined if antioxidant therapy could mitigate MV-induced diaphragm dysfunction after cervical SCI. In these experiments, SCI rats received antioxidant (Trolox, a vitamin E analog) or saline treatment prior to initiating MV. Our results demonstrate that compared with either condition alone, the combination of SCI and MV resulted in increased diaphragm atrophy, contractile dysfunction, and expression of atrophy-related genes, including MuRF1. Importantly, administration of the antioxidant Trolox attenuated proteolytic activation, fiber atrophy, and contractile dysfunction in the diaphragms of SCI + MV animals. These findings provide evidence that cervical SCI greatly exacerbates VIDD, but antioxidant therapy with Trolox can preserve diaphragm contractile function following acute SCI.

Improvements in long-term survival after spinal cord injury?

OBJECTIVE

To investigate whether there have been improvements in long-term survival after spinal cord injury in recent decades.

DESIGN

Survival analysis using time-varying covariates. The outcome variable was survival or mortality, and the explanatory variables were age, sex, level and grade of injury, and calendar year. The data were analyzed using the logistic regression model, Poisson regression model with comparison to the general population, and the computation of standardized mortality ratios for various groups.

SETTING

National Spinal Cord Injury Model Systems facilities.

PARTICIPANTS

Persons (N=31,531) who survived 2 years postinjury, were older than 10 years, and who did not require ventilator support. These persons contributed 484,979 person-years of data, with 8536 deaths over the 1973 to 2012 study period.

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

Survival; survival relative to the general population; life expectancy.

RESULTS

After adjustment for age, sex, race, etiology of injury, time since injury, and level and grade of injury, mortality in persons with spinal cord injury was higher in the 2005 to 2012 period than in 1990 to 2004 or 1980 to 1989, the odds ratios for these 3 periods were .857, .826, and .802 as compared with the 1970 to 1979 reference period.

CONCLUSIONS

There was no evidence of improvement. Long-term survival has not changed over the past 30 years.

What are the perspectives for ventilated tetraplegics? A French retrospective study of 108 patients with cervical spinal cord injury

OBJECTIVE

Tetraplegic patients are often difficult to manage in intensive care units (ICU). The aim of our study was to calculate the incidence of patients in ICU with cervical spinal cord injury with special focus on tetraplegic patients on ventilation support and their future perspectives.

MATERIALS AND METHODS

This retrospective study included patients with cervical spinal cord injury in Upper Normandy, between 2002 and 2012. Data analyzed included age, sex, past medical history, date of onset of quadriplegia, level of neurological involvement, AIS grade, and ventilatory status.

RESULTS

One hundred and eight patients were included (49.0 ± 21.1 years). The most common etiology was fall (50 patients [46.3%]). Incidence was calculated at 12.7 per one million inhabitants. Tracheotomy was performed in 40.7% of patients. Long-term mechanical ventilation was required for 6.5%. At the end of the study, 9 patients (9.6%) were permanently hospitalized, 61 patients (64.9%) had returned home but none of the four ventilated patients had been discharged.

CONCLUSION

The conclusion of this work is that the future of highly tetraplegic patients is compromised, especially for those who remain reliant on mechanical ventilation.

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.

Spinal cord trauma in children under 10 years of age: clinical characteristics and prevention

PURPOSE

This study analyzed the clinical characteristics of spinal cord injury (SCI) in children 10 years of age and younger, forms of prevention, and ways to improve treatment.

METHODS

Ninety-three children were reviewed between 1996 and 2009. The variables studied were type, age, cause, neurological level, association between SCI and traumatic brain injury (TBI), arthrodesis surgery, time elapsed between trauma and diagnosis, and causes of death. The statistical evaluations were done using the chi-square and ANOVA scales, in the SPSS program version 11.0.

RESULTS

The most common cause was automobile crash accidents. Getting run over by a car was second (29.1 %), followed by firearm injuries (11.8 %). The thoracic spine was the most commonly impacted area. Evaluation showed that 83.9 % had complete neurological injury. Associated TBI was present in 35.5 % of the cases. Only 21.5 % of the patients required arthrodesis of the spine. In 31.2 % of the cases, myelopathy was not diagnosed at the time of the accident. There was no statistical correlation between TBI and a delayed diagnosis of SCI (p=0.231). Five children (5.4 %) died.

CONCLUSIONS

The study showed that the cause of the trauma is associated to the child's age and that prevention is important. Trauma from automobile crash accidents was the main cause, and, in older children, firearm injuries are an important risk. Spinal cord injury was not always diagnosed in children at the time of accident. Educating family members and training emergency teams to adequately treat children with multiple traumas are measures that can help reduce the incidence of SCIs and neurological damage.

Respiratory Complications and Management of Mechanical Ventilation in Cervical Spine Injury

It is estimated that the annual incidence of spinal cord injury in the United States is 12 000 new cases per year. Victims of spinal cord injury are prone to developing respiratory complications such as atelectasis, pneumonia, and ventilatory failure secondary to physiologic derangements resulting from spinal shock and paralysis. Respiratory complications are the leading cause of death in those who survive the initial injury. The goal in ventilator management of spinal cord injury patients in the intensive care unit setting is to prevent these complications and optimize patients for early transfer to a spinal cord rehabilitation facility. To minimize atelectasis, current guidelines recommend the use of very high tidal volumes (15 mL/kg) or setting high tidal volumes (10 mL/kg) in addition to using positive end-expiratory pressure. In this article, the authors discuss the pulmonary complications that affect the mortality of these patients and review the evidence behind the current high tidal volume ventilation strategy.

Age, sex, and socio-economic status affect the incidence of pediatric spinal cord injury: an eleven-year national cohort study

BACKGROUND

Few studies focus on pediatric spinal cord injury (SCI) and there is little information regarding the cause, anatomic level, and high risk population of SCI in children. This study aims to investigate the incidence and risk factors of pediatric SCI.

METHODS

A nationwide cohort of 8.7 million children aged<18 years in an 11-year period was analyzed for causes, age at injury, anatomic sites, disability, and familial socio-economic factors. Incidence rates and Cox regression analysis were conducted.

RESULTS

A total of 4949 SCI patients were analyzed. The incidence rates of cervical, thoracic, lumbar, and other SCI were 4.06, 0.34, 0.75, and 0.85 per 100,000 person-years, respectively. The proportional composition of gender, age, and socio-economic status of SCI patients were significantly different than those of non-SCI patients (all p<0.001). Male children were significantly more likely to have SCI than females in both the cervical and the other SCI groups [Incidence rate ratio (IRR) = 2.03 and 1.52; both p<0.001]. Young adults and teenagers were also significantly more likely to have SCI than pre-school age children in the cervical SCI (IRR = 28.55 and 10.50, both p<0.001) and other SCI groups (IRR = 18.8 and 7.47, both p<0.001). Children in families of lower socio-economic status were also significantly more likely to have SCI (p<0.05).

CONCLUSIONS

In the pediatric population, the overall SCI incidence rate is 5.99 per 100,000 person-years, with traumatic cervical SCI accounting for the majority. The incidence rate increases abruptly in male teenagers. Gender, age, and socio-economic status are independent risk factors that should be considered.

Traumatic spinal cord injuries--incidence, mechanisms and course

BACKGROUND

The primary purpose of this article is to provide an overview of demography, neurological level of injury, extent of lesion, incidence, prevalence, injury mechanisms as well as lethality and causes of death associated with traumatic spinal cord injuries.

MATERIAL AND METHOD

A literature search was carried out in PubMed, with the search words "traumatic spinal cord injury"/"traumatic spinal cord injuries" together with "epidemiology", and "spinal cord injury"/"spinal cord injuries" together with "epidemiology".

RESULTS

The reported annual incidence of traumatic spinal cord injuries varies from 2.3 per million in a study from Canada to 83 per million in Alaska. The prevalence is given as ranging from 236 per million in India to 1800 per million in the USA. The average age at the time of injury varies from 26.8 years in Turkey to 55.5 years in the USA. The ratio of men to women varies from 0.9 in Taiwan to 12.0 in Nigeria. The most frequent cause of injury is traffic accidents, followed by falls, violence and sports/leisure activity incidents. Patients with traumatic spinal cord injuries have a higher lethality than the normal population. The most frequent causes of death today are airway problems, heart disease and suicide.

INTERPRETATION

There are large geographical differences in reported incidence, prevalence and lethality. This is attributable to differences in definition, inclusion, classification and patient identification procedures in the various studies, together with geographical and cultural differences and differences in prehospital and hospital treatment.

Gainful employment and risk of mortality after spinal cord injury: effects beyond that of demographic, injury and socioeconomic factors

OBJECTIVE

To evaluate the association of three levels of gainful employment with the risk of mortality after traumatic spinal cord injury (SCI) while controlling for known predictors of mortality status (including education and income).

STUDY DESIGN

Prospective cohort study.

SETTING

A total of 20 federally funded SCI Model Systems of care in the United States.

METHODS

Participants included 7955 adults with traumatic SCI. Preliminary assessments were conducted between 1995 and 2006. Mortality status was determined by the Social Security Death Index (1308 deaths). A two-stage logistic regression model was used to estimate the chance of dying in any given year. Life expectancy was calculated under different economic assumptions.

RESULTS

Compared with those who were working 30+ h per week, the odds of mortality was 1.37 for those who worked 1-29 h and 1.67 for those who were unemployed. The addition of gainful employment only modestly reduced the effects of household income and education, both of which remained significant. For instance, the odds of mortality for household income (referent $75 000+) decreased from 1.50 to 1.38 for $25 000-$75 000 and from 2.10 to 1.82 for < $25 000. Life expectancy varied widely depending on socioeconomic characteristics more than doubling under certain assumptions.

CONCLUSION

Substantial variation in mortality is attributable to employment, above and beyond the effects of previously established demographic, injury and socioeconomic predictors. Although some excess mortality may be the inevitable consequence of SCI, risk is substantially increased with poor socioeconomic characteristics.

Epidemiology of traumatic spinal cord injury: trends and future implications

STUDY DESIGN

Review supplemented by inception cohort.

OBJECTIVES

To review trends in the incidence, prevalence, demographic characteristics, etiology, injury severity and selected treatment outcomes of traumatic spinal cord injury (SCI).

SETTING

International review and US model systems cohort.

METHODS

An extensive literature review was conducted to identify all relevant studies of descriptive epidemiology of traumatic SCI. This review was supplemented by analyses of trends in US SCI epidemiology that are reflected in the National Spinal Cord Injury Statistical Center and Shriners Hospital Spinal Cord Injury databases.

RESULTS

Incidence and prevalence of traumatic SCI in the United States are higher than in the rest of the world. Average age at injury is increasing in accordance with an aging general population at risk. The proportion of cervical injuries is increasing, whereas the proportion of neurologically complete injuries is decreasing. Injuries due to falls are increasing. Recent gains in general population life expectancy are not reflected in the SCI population. Treatment outcomes are changing as a result of increasing age and changes in US health care delivery.

CONCLUSION

Within the prevalent population, the percentage of elderly persons will not increase meaningfully until the high mortality rates observed among older persons significantly improve. Those who reach older ages will typically have incomplete and/or lower level injuries, and will have relatively high degrees of independence and overall good health.

Stability of predictors of mortality after spinal cord injury

STUDY DESIGN

Cohort study.

OBJECTIVES

To identify the stability of socio-environmental, behavioral and health predictors of mortality over an 8-year time frame.

SETTING

Data were analyzed at a large medical university in the Southeast United States of America (USA).

METHODS

Adults with residual impairment from a spinal cord injury (SCI) who were at least 1-year post-injury at assessment were recruited through a large specialty hospital in the Southeast USA. A total of 1209 participants were included in the final analysis. A piecewise exponential model with two equal time intervals (8 years total) was used to assess the stability of the hazard and the predictors over time.

RESULTS

The hazard did significantly change over time, where the hazard in the first time interval was significantly lower than the second. There were no interactions between the socio-environmental, behavior or health factors and time, although there was a significant interaction between age at injury (a demographic variable) and time.

CONCLUSION

These results suggest there is stability in the association between the predictors and mortality, even over an 8-year time period. Results reinforce the use of historic variables for prediction of mortality in persons with SCI.

Health, secondary conditions, and life expectancy after spinal cord injury

OBJECTIVE

To evaluate the association of health status, secondary health conditions, hospitalizations, and risk of mortality and life expectancy (LE) after spinal cord injury (SCI).

DESIGN

Prospective cohort study.

SETTING

Preliminary data were collected from a specialty hospital in the Southeastern United States, with mortality follow-up and data analysis conducted at a medical university.

PARTICIPANTS

Adults with traumatic SCI (N=1361), all at least 1-year postinjury at the time of assessment, were enrolled in the study. There were 325 deaths. After elimination of those with missing data on key variables, there were 267 deaths and 12,032 person-years.

INTERVENTIONS

None.

MAIN OUTCOME MEASURES

The mortality status was determined by routine follow-up using the National Death Index through December 31, 2008. A logistic regression model was developed to estimate the probability of dying in any given year using person-years.

RESULTS

A history of chronic pressure ulcers, amputations, a depressive disorder, symptoms of infections, and being hospitalized within the past year were all predictive of mortality. LE estimates were generated using the example of a man with noncervical, nonambulatory SCI. Using 3 age examples (20, 40, 60y), the greatest estimated lost LE was associated with chronic pressure ulcers (50.3%), followed by amputations (35.4%), 1 or more recent hospitalizations (18.5%), and the diagnosis of probable major depression (18%). Symptoms of infections were associated with a 6.7% reduction in LE for a 1 SD increase in infectious symptoms.

CONCLUSIONS

Several secondary health conditions represent risk factors for mortality and diminish LE after SCI. The presence of 1 or more of these factors should be taken as an indicator of the need for intervention.

Home mechanical ventilation: a Canadian Thoracic Society clinical practice guideline

Increasing numbers of patients are surviving episodes of prolonged mechanical ventilation or benefitting from the recent availability of userfriendly noninvasive ventilators. Although many publications pertaining to specific aspects of home mechanical ventilation (HMV) exist, very few comprehensive guidelines that bring together all of the current literature on patients at risk for or using mechanical ventilatory support are available. The Canadian Thoracic Society HMV Guideline Committee has reviewed the available English literature on topics related to HMV in adults, and completed a detailed guideline that will help standardize and improve the assessment and management of individuals requiring noninvasive or invasive HMV. The guideline provides a disease-specific review of illnesses including amyotrophic lateral sclerosis, spinal cord injury, muscular dystrophies, myotonic dystrophy, kyphoscoliosis, post-polio syndrome, central hypoventilation syndrome, obesity hypoventilation syndrome, and chronic obstructive pulmonary disease as well as important common themes such as airway clearance and the process of transition to home. The guidelines have been extensively reviewed by international experts, allied health professionals and target audiences. They will be updated on a regular basis to incorporate any new information.