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

Clinical risk factors associated with the need for tracheostomy in traumatic cervical and high thoracic spinal cord injury

BACKGROUND

Our objective was to assess the association of completeness and level of spinal cord injury (SCI) with the need for tracheostomy and identify additional risk factors predictive of tracheostomy.

METHODS

This was a retrospective review of patients with SCI between January 2017 and December 2022.

RESULTS

Patients with complete SCI were roughly thirty-three times more likely to have a tracheostomy when compared to incomplete injury (82 ​% vs 12 ​%, p ​< ​0.001, OR ​= ​32.9). The rate of tracheostomy did not differ between spinal cord levels for complete (p ​= ​0.68) or incomplete (p ​= ​0.08) injuries. Penetrating injury, low GCS, high ISS, and polytrauma were associated with tracheostomy need in incomplete SCI.

CONCLUSION

Complete injury was statistically significantly associated with the need for tracheostomy while level of injury failed to reach significance. Patients with incomplete SCI that have certain clinical risk factors should be considered for early tracheostomy.

Critical Care of Spinal Cord Injury

PURPOSE OF REVIEW

Spinal cord injury (SCI) is a major cause of morbidity and mortality, posing a significant financial burden on patients and the healthcare system. While little can be done to reverse the primary mechanical insult, minimizing secondary injury due to ischemia and inflammation and avoiding complications that adversely affect neurologic outcome represent major goals of management. This article reviews important considerations in the acute critical care management of SCI to improve outcomes.

RECENT FINDINGS

Neuroprotective agents, such as riluzole, may allow for improved neurologic recovery but require further investigation at this time. Various forms of neuromodulation, such as transcranial magnetic stimulation, are currently under investigation. Early decompression and stabilization of SCI is recommended within 24 h of injury when indicated. Spinal cord perfusion may be optimized with a mean arterial pressure goal from a lower limit of 75-80 to an upper limit of 90-95 mmHg for 3-7 days after injury. The use of corticosteroids remains controversial; however, initiation of a 24-h infusion of methylprednisolone 5.4 mg/kg/hour within 8 h of injury has been found to improve motor scores. Attentive pulmonary and urologic care along with early mobilization can reduce in-hospital complications.

Quantifying the Association Between Surgical Spine Approach and Tracheostomy Timing After Traumatic Cervical Spinal Cord Injury

BACKGROUND AND OBJECTIVES

Recent evidence suggests earlier tracheostomy is associated with fewer complications in patients with complete cervical spinal cord injury (SCI). This study aims to evaluate the influence of spine surgical approach on the association between tracheostomy timing and in-hospital adverse events treating patients with complete cervical SCI.

METHODS

This retrospective cohort study was performed using Trauma Quality Improvement Program data from 2017 to 2020. All patients with acute complete (American Spinal Injury Association-A) cervical SCI who underwent tracheostomy and spine surgery were included. Tracheostomy timing was dichotomized to early (within 1 week after surgery) and delayed (more than 1 week after surgery). Primary outcome was the occurrence of major in-hospital complications. Secondary outcomes included occurrences of immobility-related complications, surgical-site infection, hospital and intensive care unit length of stay, and time on mechanical ventilation.

RESULTS

The study included 1592 patients across 358 trauma centers. Mean time to tracheostomy from surgery was 8.6 days. A total of 495 patients underwent anterior approach, 670 underwent posterior approach, and 427 underwent combined anterior and posterior approach. Patients who underwent anterior approach were significantly more likely to have delayed tracheostomy compared with posterior approach (53% vs 40%, P < .001). Early tracheotomy significantly reduced major in-hospital complications (odds ratio 0.67, 95% CI 0.53-0.84) and immobility complications (odds ratio = 0.78, 95% CI 0.6-1.0). Those undergoing early tracheostomy spent 6.0 (95% CI -8.47 to -3.43) fewer days in hospital, 5.7 (95% CI -7.8 to -3.7) fewer days in the intensive care unit, and 5.9 (95% CI -8.2 to -3.7) fewer days ventilated. Surgical approach had no significant negative effect on the association between tracheostomy timing and the outcomes of interest.

CONCLUSION

Earlier tracheostomy for patients with cervical SCI is associated with reduced complications, length of stay, and ventilation time. This relationship appears independent of the surgical approach. These findings emphasize that tracheostomy need not be delayed because of the SCI treatment approach.

Factors Associated With Tracheostomy in Ventilated Pediatric Trauma Patients. A National Trauma Database Study

PURPOSE

The purpose of the study was to find the factors that were associated with tracheostomy procedures in ventilated pediatric trauma patients.

METHODS

The Trauma Quality Improvement Program (TQIP) database of the calendar year 2017 through 2019 was accessed for the study. All patients <18 years old and who were on mechanical ventilation for more than 96 hours were included in the study. Multiple logistic regression analysis was performed to find the factors that were associated with a tracheostomy.

RESULTS

Out of 2653 patients, 1907 (71.88%) patients underwent tracheostomy. The patients who underwent tracheostomy had a lower median [IQR] of Glasgow Coma Scale (GCS) (3 [3-8] vs 5 [3-10], P < .001) and had a higher proportion of severe spine injury (On Abbreviated Injury Scale [AIS]≥3) (11.6% vs 8.8%, P = .044) when compared with patients who did not have tracheostomy. Lower GCS scores and severe spine injury were associated with higher odds of tracheostomy, with all P values <.05. Higher proportion of tracheostomy procedures were performed at level I pediatric trauma centers as compared to non-designated pediatric centers (odds ratio [95% CI]: 1.848 [1.524-2.242], P < .001).

CONCLUSION

A lower GCS score, severe spine injury and highest level trauma centers were associated with a tracheostomy.

Predicting extubation in patients with traumatic cervical spinal cord injury using the diaphragm electrical activity during a single maximal maneuver

BACKGROUND

The unsuccessful extubation in patients with traumatic cervical spinal cord injuries (CSCI) may result from impairment diaphragm function and monitoring of diaphragm electrical activity (EAdi) can be informative in guiding extubation. We aimed to evaluate whether the change of EAdi during a single maximal maneuver can predict extubation outcomes in CSCI patients.

METHODS

This is a retrospective study of CSCI patients requiring mechanical ventilation in the ICU of a tertiary hospital. A single maximal maneuver was performed by asking each patient to inhale with maximum strength during the first spontaneous breathing trial (SBT). The baseline (during SBT before maximal maneuver), maximum (during the single maximal maneuver), and the increase of EAdi (ΔEAdi, equal to the difference between baseline and maximal) were measured. The primary outcome was extubation success, defined as no reintubation after the first extubation and no tracheostomy before any extubation during the ICU stay.

RESULTS

Among 107 patients enrolled, 50 (46.7%) were extubated successfully at the first SBT. Baseline EAdi, maximum EAdi, and ΔEAdi were significantly higher, and the rapid shallow breathing index was lower in patients who were extubated successfully than in those who failed. By multivariable logistic analysis, ΔEAdi was independently associated with successful extubation (OR 2.03, 95% CI 1.52-3.17). ΔEAdi demonstrated high diagnostic accuracy in predicting extubation success with an AUROC 0.978 (95% CI 0.941-0.995), and the cut-off value was 7.0 μV.

CONCLUSIONS

The increase of EAdi from baseline SBT during a single maximal maneuver is associated with successful extubation and can help guide extubation in CSCI patients.

A Fast-Track Respiratory Protocol for High Cervical Spine Injury: A Case Report

BACKGROUND

Cervical spinal cord injury can greatly affect pulmonary function, resulting in complications, including respiratory failure with prolonged mechanical ventilation, ultimately leading to increased mortality and high health care costs. Weaning from mechanical ventilation is particularly challenging in patients with complete high spinal cord injury.

CASE PRESENTATION

We present the case of a 42-year-old man who suffered a complete cervical 5-6 spinal cord injury following a rollover motor vehicle crash and subsequently developed postoperative pneumonia and severe hypoxemic respiratory failure. He received a novel approach to fast-track respiratory care, including early and aggressive secretion clearance management, moderate pressure level of airway pressure release ventilation, timely transition to spontaneous mode, early tracheostomy and humane care, and high-flow oxygenation via tracheotomy after weaning off the ventilator. As a result, the patient experienced significant improvement in pulmonary function and was successfully liberated from the ventilator within a 2-week period.

CONCLUSION

This case highlights the potential effectiveness of fast-track respiratory care in promoting lung function restoration and expediting liberation from mechanical ventilation in patients with severe hypoxemic respiratory failure following a complete cervical spinal cord injury. However, further research is warranted to validate these findings and expand our understanding in this area.

Respiratory Complications and Weaning Considerations for Patients with Spinal Cord Injuries: A Narrative Review

Respiratory complications following traumatic spinal cord injury are common and are associated with high morbidity and mortality. The inability to cough and clear secretions coupled with weakened respiratory and abdominal muscles commonly leads to respiratory failure, pulmonary edema, and pneumonia. Higher level and severity of the spinal cord injury, history of underlying lung pathology, history of smoking, and poor baseline health status are potential predictors for patients that will experience respiratory complications. For patients who may require prolonged intubation, early tracheostomy has been shown to lead to improved outcomes. Prediction models to aid clinicians with the decision and timing of tracheostomy have been shown to be successful but require larger validation studies in the future. Mechanical ventilation weaning strategies also require further investigation but should focus on a combination of optimizing ventilator setting, pulmonary toilet techniques, psychosocial well-being, and an aggressive bowel regimen.

Diaphragm pacing implantation in Japan for a patient with cervical spinal cord injury: A case report

RATIONALE

Traumatic cervical spinal cord injury (SCI) is a devastating condition leading to respiratory failure that requires permanent mechanical ventilation, which is the main driver of increased medical costs. There is a great demand for establishing therapeutic interventions to treat respiratory dysfunction following severe cervical SCI.

PATIENT CONCERNS AND DIAGNOSIS

We present a 24-year-old man who sustained a cervical displaced C2-C3 fracture with SCI due to a traffic accident. As the patient presented with tetraplegia and difficulty in spontaneous breathing following injury, he was immediately intubated and placed on a ventilator with cervical external fixation by halo orthosis. The patient then underwent open reduction and posterior fusion of the cervical spine 3 weeks after injury. Although the patient showed significant motor recovery of the upper and lower limbs over time, only a slight improvement in lung capacity was observed.

INTERVENTIONS AND OUTCOMES

At 1.5 years after injury, a diaphragmatic pacing stimulator was surgically implanted to support the patient's respiratory function. The mechanical ventilator support was successfully withdrawn from the patient 14 weeks after implantation. We observed that both the vital capacity and tidal volume of the patient were significantly promoted following implantation. The patient finally returned to daily life without any mechanical support.

LESSONS

The findings of this report suggest that diaphragmatic pacing implantation could be a promising treatment for improving respiratory function after severe cervical SCI. To our knowledge, this is the first SCI patient treated with a diaphragm pacing implantation covered by official medical insurance in Japan.

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.

Timing of tracheostomy in acute traumatic spinal cord injury: A systematic review and meta-analysis

BACKGROUND

Patients with acute traumatic cervical or high thoracic level spinal cord injury (SCI) typically require mechanical ventilation (MV) during their acute admission. Placement of a tracheostomy is preferred when prolonged weaning from MV is anticipated. However, the optimal timing of tracheostomy placement in patients with acute traumatic SCI remains uncertain. We systematically reviewed the literature to determine the effects of early versus late tracheostomy or prolonged intubation in patients with acute traumatic SCI on important clinical outcomes.

METHODS

Six databases were searched from their inception to January 2020. Conference abstracts from relevant proceedings and the gray literature were searched to identify additional studies. Data were obtained by two independent reviewers to ensure accuracy and completeness. The quality of observational studies was evaluated using the Newcastle Ottawa Scale.

RESULTS

Seventeen studies (2,804 patients) met selection criteria, 14 of which were published after 2009. Meta-analysis showed that early tracheostomy was not associated with decreased short-term mortality (risk ratio [RR], 0.84; 95% confidence interval [CI], 0.39-1.79; p = 0.65; n = 2,072), but was associated with a reduction in MV duration (mean difference [MD], 13.1 days; 95% CI, -6.70 to -21.11; p = 0.0002; n = 855), intensive care unit length of stay (MD, -10.20 days; 95% CI, -4.66 to -15.74; p = 0.0003; n = 855), and hospital length of stay (MD, -7.39 days; 95% CI, -3.74 to -11.03; p < 0.0001; n = 423). Early tracheostomy was also associated with a decreased incidence of ventilator-associated pneumonia and tracheostomy-related complications (RR, 0.86; 95% CI, 0.75-0.98; p = 0.02; n = 2,043 and RR, 0.64; 95% CI, 0.48-0.84; p = 0.001; n = 812 respectively). The majority of studies ranked as good methodologic quality on the Newcastle Ottawa Scale.

CONCLUSION

Early tracheostomy in patients with acute traumatic SCI may reduce duration of mechanical entilation, length of intensive care unit stay, and length of hospital stay. Current studies highlight the lack of high-level evidence to guide the optimal timing of tracheostomy in acute traumatic SCI. Future research should seek to understand whether early tracheostomy improves patient comfort, decreases duration of sedation, and improves long-term outcomes.

LEVEL OF EVIDENCE

Systematic Review, level III.

Spinal cord injury and degenerative cervical myelopathy

Spinal cord injury (SCI) often results in impaired respiratory function. Paresis or paralysis of inspiratory and expiratory muscles can lead to respiratory dysfunction depending on the level and severity of the injury, which can affect the management and care of SCI patients. Respiratory dysfunction after SCI is more severe in high cervical injuries, with vital capacity (VC) being an essential indicator of overall respiratory health. Respiratory complications include hypoventilation, a reduction in surfactant production, mucus plugging, atelectasis, and pneumonia. Respiratory management includes mechanical ventilation and tracheostomy in high cervical SCI, while noninvasive ventilation is more common in patients with lower cervical and thoracic injuries. Mechanical ventilation can negatively impact the function of the diaphragm and weaning should start as soon as possible. Patients can sometimes be weaned from mechanical ventilation with assistance of electrical stimulation of the phrenic nerve or the diaphragm. Respiratory muscle training regimens may also improve patients' inspiratory function following SCI. Despite the critical advances in preventing, diagnosing, and treating respiratory complications, they continue to significantly affect persons living with SCI. Additional studies of interventions to reduce respiratory complications are likely to further decrease the morbidity and mortality associated with these injuries.

Rostral-caudal effect of cervical magnetic stimulation on the diaphragm motor evoked potential following cervical spinal cord contusion in the rat

The present study was designed to investigate the rostro-caudal effect of spinal magnetic stimulation on diaphragmatic motor-evoked potentials following cervical spinal cord injury. The diaphragm electromyogram was recorded in rats that received a laminectomy or a left mid-cervical contusion at the acute (1 day), subchronic (2 weeks), or chronic (8 weeks) injured stages. The center of a figure-eight coil was placed at 30 mm lateral to bregma on the left side, and the effect of magnetic stimulation was evaluated by stimulating the rostral, middle, and caudal cervical regions in spontaneously breathing rats. The results demonstrated that cervical magnetic stimulation induced intensity-dependent motor-evoked potentials in the bilateral diaphragm in both uninjured and contused rats; however, the left diaphragm exhibited a higher amplitude and earlier onset than the right diaphragm. Moreover, the intensity-response curve was shifted upward in the rostral-to-caudal direction of magnetic stimulation, suggesting that caudal cervical magnetic stimulation produced more robust diaphragmatic motor-evoked potentials compared to rostral cervical magnetic stimulation. Interestingly, the diaphragmatic motor-evoked potentials were similar between uninjured and contused rats during cervical magnetic stimulation despite weaker inspiratory diaphragmatic activity in contused rats. Additionally, in contused animals but not uninjured animals, diaphragmatic motor-evoked potential amplitude were greater at the chronic stage than during earlier injured stages. These results demonstrated that cervical magnetic stimulation can excite the residual phrenic motor circuit to activate the diaphragm in the presence of a significant lesion in the cervical spinal cord. These findings indicate that this non-invasive approach is effective for modulating diaphragmatic excitability following cervical spinal cord injury.

Perioperative management of spinal cord injury: the anesthesiologist's point of view

BACKGROUND

Traumatic spinal cord injury (SCI) is one of the most devastating events a person can experience. It may be life-threatening or result in long-term disability. This narrative review aims to delineate a systematic step-wise airways, breathing, circulation and disability (ABCD) approach to perioperative patient management during spinal cord surgery in order to fill some of the gaps in our current knowledge.

METHODS

We performed a comprehensive review of the literature regarding the perioperative management of traumatic spinal injuries from May 15, 2020, to December 13, 2020. We consulted the PubMed and Embase database libraries.

RESULTS

Videolaryngoscopy supplements the armamentarium available for airway management. Optical fiberscope use should be evaluated when intubating awake patients. Respiratory complications are frequent in the acute phase of traumatic spinal injury, with an estimated incidence of 36-83%. Early tracheostomy can be considered for expected difficult weaning from mechanical ventilation. Careful intraoperative management of administered fluids should be pursued to avoid complications from volume overload. Neuromonitoring requires investments in staff training and cooperation, but better outcomes have been obtained in centers where it is routinely applied. The prone position can cause rare but devastating complications, such as ischemic optic neuropathy; thus, the anesthetist should take the utmost care in positioning the patient.

CONCLUSIONS

A one-size fit all approach to spinal surgery patients is not applicable due to patient heterogeneity and the complexity of the procedures involved. The neurologic outcome of spinal surgery can be improved, and the incidence of complications reduced with better knowledge of patient-specific aspects and individualized perioperative management.

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).

High tidal volume ventilation is associated with ventilator-associated pneumonia in acute cervical spinal cord injury

CONTEXT/OBJECTIVE

Pneumonia is the leading cause of death after acute spinal cord injury (SCI). High tidal volume ventilation (HVtV) is used in SCI rehabilitation centers to overcome hypoventilation while weaning patients from the ventilator. Our objective was to determine if HVtV in the acute post-injury period in SCI patients is associated with lower incidence of ventilator-associated pneumonia (VAP) when compared to patients receiving standard tidal volume ventilation.

DESIGN

Cohort study.

SETTING

Red Duke Trauma Institute, University of Texas Health Science Center at Houston, TX, USA.

PARTICIPANTS

Adult Acute Cervical SCI Patients, 2011-2018.

INTERVENTIONS

HVtV.

OUTCOME MEASURES

VAP, ventilator dependence at discharge, in-hospital mortality.

RESULTS

Of 181 patients, 85 (47%) developed VAP. HVtV was utilized in 22 (12%) patients. Demographics, apart from age, were similar between patients who received HVtV and standard ventilation; patients were younger in the HVtV group. VAP developed in 68% of patients receiving HVtV and in 44% receiving standard tidal volumes (P = 0.06). After adjustment, HVtV was associated with a 1.96 relative risk of VAP development (95% credible interval 1.55-2.17) on Bayesian analysis. These results correlate with a >99% posterior probability that HVtV is associated with increased VAP when compared to standard tidal volumes. HVtV was also associated with increased rates of ventilator dependence.

CONCLUSIONS

While limited by sample size and selection bias, our data revealed an association between HVtV and increased VAP. Further investigation into optimal early ventilation settings is needed for SCI patients, who are at a high risk of VAP.

A Prognostic Factor for Prolonged Mechanical Ventilator-Dependent Respiratory Failure after Cervical Spinal Cord Injury : Maximal Canal Compromise on Magnetic Resonance Imaging

Objective

The period of mechanical ventilator (MV)-dependent respiratory failure after cervical spinal cord injury (CSCI) varies from patient to patient. This study aimed to identify predictors of MV at hospital discharge (MVDC) due to prolonged respiratory failure among patients with MV after CSCI.

Methods

Two hundred forty-three patients with CSCI were admitted to our institution between May 2006 and April 2018. Their medical records and radiographic data were retrospectively reviewed. Level and completeness of injury were defined according to the American Spinal Injury Association (ASIA) standards. Respiratory failure was defined as the requirement for definitive airway and assistance of MV. We also evaluated magnetic resonance imaging characteristics of the cervical spine. These characteristics included : maximum canal compromise (MCC); intramedullary hematoma or cord transection; and integrity of the disco-ligamentous complex for assessment of the Subaxial Cervical Spine Injury Classification (SLIC) scoring. The inclusion criteria were patients with CSCI who underwent decompression surgery within 48 hours after trauma with respiratory failure during hospital stay. Patients with Glasgow coma scale 12 or lower, major fatal trauma of vital organs, or stroke caused by vertebral artery injury were excluded from the study.

Results

Out of 243 patients with CSCI, 30 required MV during their hospital stay, and 27 met the inclusion criteria. Among them, 48.1% (13/27) of patients had MVDC with greater than 30 days MV or death caused by aspiration pneumonia. In total, 51.9% (14/27) of patients could be weaned from MV during 30 days or less of hospital stay (MV days : MVDC 38.23±20.79 vs. MV weaning, 13.57±8.40; p<0.001). Vital signs at hospital arrival, smoking, the American Society of Anesthesiologists classification, Associated injury with Injury Severity Score, SLIC score, and length of cord edema did not differ between the MVDC and MV weaning groups. The ASIA impairment scale, level of injury within C3 to C6, and MCC significantly affected MVDC. The MCC significantly correlated with MVDC, and the optimal cutoff value was 51.40%, with 76.9% sensitivity and 78.6% specificity. In multivariate logistic regression analysis, MCC >51.4% was a significant risk factor for MVDC (odds ratio, 7.574; p=0.039).

Conclusion

As a method of predicting which patients would be able to undergo weaning from MV early, the MCC is a valid factor. If the MCC exceeds 51.4%, prognosis of respiratory function becomes poor and the probability of MVDC is increased.

Survival among patients with severe high cervical spine injuries - a TraumaRegister DGU® database study

BACKGROUND

Trauma is a significant cause of death and impairment. The Abbreviated Injury Scale (AIS) differentiates the severity of trauma and is the basis for different trauma scores and prediction models. While the majority of patients do not survive injuries which are coded with an AIS 6, there are several patients with a severe high cervical spinal cord injury that could be discharged from hospital despite the prognosis of trauma scores. We estimate that the trauma scores and prediction models miscalculate these injuries. For this reason, we evaluated these findings in a larger control group.

METHODS

In a retrospective, multi-centre study, we used the data recorded in the TraumaRegister DGU® (TR-DGU) to select patients with a severe cervical spinal cord injury and an AIS of 3 to 6 between 2002 to 2015. We compared the estimated mortality rate according to the Revised Injury Severity Classification II (RISC II) score against the actual mortality rate for this group.

RESULTS

Six hundred and twelve patients (0.6%) sustained a severe cervical spinal cord injury with an AIS of 6. The mean age was 57.8 ± 21.8 years and 441 (72.3%) were male. 580 (98.6%) suffered a blunt trauma, 301 patients were injured in a car accident and 29 through attempted suicide. Out of the 612 patients, 391 (63.9%) died from their injury and 170 during the first 24 h. The group had a predicted mortality rate of 81.4%, but we observed an actual mortality rate of 63.9%.

CONCLUSIONS

An AIS of 6 with a complete cord syndrome above C3 as documented in the TR-DGU is survivable if patients get to the hospital alive, at which point they show a survival rate of more than 35%. Compared to the mortality prognosis based on the RISC II score, they survived much more often than expected.

Spinal cord injury level and Phrenic Nerve Conduction Studies do not predict diaphragm pacing success or failure- all patients should undergo diagnostic laparoscopy

BACKGROUND

Diaphragm Pacing(DP) demonstrates benefits over mechanical ventilation(MV) for spinal cord injured(SCI) patients. The hypothesis of this report is that phrenic nerve conduction study(PNCS) results cannot differentiate success or failure in selection of patients for DP. Direct surgical evaluation of the diaphragm should be performed.

METHODS

Observational report of prospective databases of patients undergoing laparoscopic evaluation of their diaphragms to assess for ability to stimulate to cause contraction for ventilation.

RESULTS

In 50 SCI patients who could not be weaned from MV, PNCS results showed latencies in stimulated patients (n = 44) and non-stimulated(n = 6) overlapped (7.8 ± 2.5 ms vs 9.4 ± 2.8 ms) and the null hypothesis cannot be rejected (p-value>0.05). Amplitudes overlapped (0.4 ± 0.2 mV vs 0.2 ± 0.2 mV) and the null hypotheses cannot be rejected (P-value >0.05). In 125 non SCI patients with diaphragm paralysis, there were 78(62.4%) with false negative PNCS.

CONCLUSION

PNCS are inadequate pre-operative studies. Direct laparoscopic evaluation should be offered for all SCI patients to receive the benefit of DP.

Molecular Profiling of Innate Immune Response Mechanisms in Ventilator-associated Pneumonia

Ventilator-associated pneumonia (VAP) is a common hospital-acquired infection, leading to high morbidity and mortality. Currently, bronchoalveolar lavage (BAL) is used in hospitals for VAP diagnosis and guiding treatment options. Although BAL collection procedures are invasive, alternatives such as endotracheal aspirates (ETA) may be of diagnostic value, however, their use has not been thoroughly explored. Longitudinal ETA and BAL were collected from 16 intubated patients up to 15 days, of which 11 developed VAP. We conducted a comprehensive LC-MS/MS based proteome and metabolome characterization of longitudinal ETA and BAL to detect host and pathogen responses to VAP infection. We discovered a diverse ETA proteome of the upper airways reflective of a rich and dynamic host-microbe interface. Prior to VAP diagnosis by microbial cultures from BAL, patient ETA presented characteristic signatures of reactive oxygen species and neutrophil degranulation, indicative of neutrophil mediated pathogen processing as a key host response to the VAP infection. Along with an increase in amino acids, this is suggestive of extracellular membrane degradation resulting from proteolytic activity of neutrophil proteases. The metaproteome approach successfully allowed simultaneous detection of pathogen peptides in patients' ETA, which may have potential use in diagnosis. Our findings suggest that ETA may facilitate early mechanistic insights into host-pathogen interactions associated with VAP infection and therefore provide its diagnosis and treatment.

Risk factors for tracheostomy after traumatic cervical spinal cord injury

OBJECTIVE

To determine the risk factors for the need of tracheostomy after cervical spinal cord injury (CSCI) at the acute stage.

METHODS

The authors retrospectively reviewed 294 patients with acute traumatic CSCI in Xinqiao Hospital between 2012 and 2016 and analyzed the factors postulated to increase the risk for tracheostomy, including patient's age, neurological impairment scale grade and level, smoking history, combined injury, and surgical intervention. Logistic regression analysis was used to identify independent risk factor for the need of tracheostomy.

RESULTS

Of 294 patients, 52 patients received tracheostomy (17.7%). The factor identified by demographics and outcomes were smoking history, cause of injury, neurological impairment scale grade and level, and combined dislocation. A multiple logistic regression model demonstrated that age of 60 years older, combined facet dislocation, C4 level high, and the American Spinal Injury Association (ASIA) A and B scale were predictive of need for tracheostomy on 95% occasions.

CONCLUSION

The high age of 60 years, combined facet dislocation, C4 level high, and ASIA A and B scale are indispensable to predict the need for tracheostomy in patients with CSCI at the acute stage.

Factors Associated With Prolonged Mechanical Ventilation and Reventilation in Acute Cervical Spinal Cord Injury Patients

MINI: In this study, respiratory function at the time of extubation can be useful optimal clinical guidelines for weaning and extubation attempts in patients with acute cervical spinal cord injury. Serum thiobarbituric acid-reactive substances level at admission can be a useful predictor for severity in acute cervical patients with spinal cord injury.

STUDY DESIGN

Patients who had suffered from acute blunt cervical spinal cord injury (SCI) and admitted our hospital within 24 hours after injury were included in the study.

OBJECTIVE

We compared the respiratory function and serum reactive oxidative stress (ROS) after acute cervical SCI, and tried to find out the valuable predictors of weaning in patients with acute cervical SCI.

SUMMARY OF BACKGROUND DATA

Ventilation impairment is a major complication of acute cervical SCI. Evidence of oxygen radical formation in secondary injury from animal SCI models demonstrates an immediate postinjury increase in ROS production after SCI. We hypothesize that the serum ROS is associated with the severity of patients with acute cervical SCI.

METHODS

Thirty-eight adult patients who had acute cervical SCI and 58 healthy volunteers were enrolled. Respiratory function at admission, at the time of extubation and at 48 hours after extubation, serum oxidative stress, Injury Severity Score and Japanese Orthopaedic Association score at admission were compared.

RESULTS

The most notable predictor of mechanical ventilation more than 48 hours was serum thiobarbituric acid-reactive substances (TBARS) level at admission (P = 0.027), and the cut-off value of serum TBARS level was 731.7 μmol/L (sensitivity 87.5% and specificity 78.9%). For the reventilation ≤5 days, the notable predictors were respiratory function at the time of extubation (maximal inspiratory pressure, P = 0.040; maximal expiratory pressure, P = 0.020; and tidal volume, P = 0.036) and serum TBARS level at admission (P = 0.013), the cut-off value of serum TBARS level at admission was 762.3 μmol/L (sensitivity 100% and specificity 90.0%).

CONCLUSION

In this study, respiratory function (maximal inspiratory pressure, maximal expiratory pressure, and tidal volume) at the time of extubation can be useful optimal clinical guidelines for weaning and extubation attempts in patients with acute cervical SCI. Serum TBARS level at admission can be a useful predictor for severity in acute cervical SCI patients.

LEVEL OF EVIDENCE

3.

Acute cervical spinal cord injury and extubation failure: A systematic review and meta-analysis

PURPOSE

Respiratory complications are the most significant cause of morbidity and mortality in acute cervical spinal cord injury (CSCI). The prevalence of extubation failure (EF) and factors associated with it are unclear. This research aimed to systematically synthesise and pool literature describing EF and associated risk factors in acute CSCI.

METHODS

A systematic review was performed using medical literature analysis and retrieval system online, cummulative index of nursing and allied health literature, excerpta medica dataBASE, and Cochrane library. Articles were screened using the preferred reporting items for systematic reviews and meta-analyses (PRISMA) guidelines. A proportion meta-analysis was conducted to pool rates of EF. Odds ratios and weighted mean differences were calculated to evaluate risk factors. The R statistical software package was used.

RESULTS

Of the 347 articles that were identified, six articles satisfied the inclusion criteria (387 participants). The pooled EF rate was 20.25% (10.13-36.38%). Type of CSCI was the only statistically significant risk factor. The odds of EF occurring were 2.76 [95% confidence interval (CI): 1.14; 6.70] times greater for complete CSCI than for incomplete CSCI.

CONCLUSIONS

One in five patients with acute cervical SCI fails extubation. The odds of EF occurring are almost three times greater in complete CSCI. Future research should aim to improve standard data sets and prospective evaluation of adjuvant therapy in the peri-extubation period.

Long-term experience with diaphragm pacing for traumatic spinal cord injury: Early implantation should be considered

BACKGROUND

Cervical spinal cord injury can result in catastrophic respiratory failure requiring mechanical ventilation with high morbidity, mortality, and cost. Diaphragm pacing was developed to replace/decrease mechanical ventilation. We report the largest long-term results in traumatic cervical spinal cord injury.

METHODS

In this retrospective review of prospective institutional review board protocols, all patients underwent laparoscopic diaphragm mapping and implantation of electrodes for diaphragm strengthening and ventilator weaning.

RESULTS

From 2000 to 2017, 92 patients out of 486 diaphragm pacing implants met the criteria. The age at time of injury ranged from birth to 74 years (average: 27 years). Time on mechanical ventilation was an average of 47.5 months (range, 6 days to 25 years, median = 1.58 years). Eighty-eight percent of patients achieved the minimum of 4 hours of pacing. Fifty-six patients (60.8%) used diaphragm pacing 24 hours a day. Five patients had full recovery of breathing with subsequent diaphragm pacing removal. Median survival was 22.2 years (95% confidence interval: 14.0-not reached) with only 31 deaths. Subgroup analysis revealed that earlier diaphragm pacing implantation leads to greater 24-hour use of diaphragm pacing and no need for any mechanical ventilation.

CONCLUSION

Diaphragm pacing can successfully decrease the need for mechanical ventilation in traumatic cervical spinal cord injury. Earlier implantation should be considered.

The impact of a specialized spinal cord injury center as compared with non-specialized centers on the acute respiratory management of patients with complete tetraplegia: an observational study

STUDY DESIGN

Retrospective cohort study.

OBJECTIVES

To compare the proportion of tracheostomy placement and duration of mechanical ventilation (MV) in patients with a complete cervical spinal cord injury (SCI) that were managed early or lately in a specialized acute SCI-center. The second objective was to determine the impact of the timing of admission to the SCI-center on the MV support duration.

SETTING

A single Level-1 trauma center specialized in SCI care in Quebec (Canada).

METHODS

A cohort of 81 individuals with complete tetraplegia over a 6-years period was included. Group 1 (N = 57- early group-) was admitted before surgical management in one specialized acute SCI-center, whereas Group 2 (N = 24 -late group-) was surgically managed in a non-specialized center and transferred to the SCI-center for post-operative management only. The proportion of tracheostomy placement and MV duration were compared. Multivariate regression analysis was used to assess the impact of the timing of admission to the SCI-center on the MV duration during the SCI-center stay.

RESULTS

Patients in Group 2 had a higher proportion of tracheostomy (70.8 vs. 35.1%, p = 0.004) and a higher mean duration of MV support (68.0 ± 64.2 days vs. 21.8 ± 29.7 days, p = 0.006) despite similar age, trauma severity (ISS), neurological level of injury and proportion of pneumonia. Later transfer to the specialized acute SCI-center was the main predictive factor of longer MV duration, with a strong impact factor (s = 946.7, p < 0.001).

CONCLUSIONS

Early admission to a specialized acute SCI-center for surgical and peri-operative management after a complete tetraplegia is associated with lower occurrence of tracheostomy and shorter mechanical ventilation duration support.

SPONSORSHIP

MENTOR Program of the Canadian Institute of Health Research and US Department of Defense Spinal Cord Injury Research Program.

Risk factors and the surgery affection of respiratory complication and its mortality after acute traumatic cervical spinal cord injury

The aim of this study is to estimate the risk factors of both respiratory complication (RC) and mortality after acute traumatic cervical spinal cord injury (TCSCI). Between July 2005 and July 2015, in 181 patients (142 males and 39 females; mean age 41.0 years) with acute TCSCI, we compared the difference and odds ratio in RC group (n = 73) with that of non-RC group (n = 108), and also death group (n = 15) and survival group (n = 166). We collected injury-related information after half a year of injury, which is as follows: the causes of injury, time of surgery, ICU (intensive care unit) days, ventilator days, ASIA (American Spinal Injury Association) classification, neurological injury, CIPS (Clinical Pulmonary Infection Score), and BMI (body mass index). Besides these, we gathered the general information such as age, gender, smoking history, and use of steroids. The study compared perioperative parameters; surgery-related and instrumentation- and graft-related complication rates; clinical parameters; patient satisfaction; and radiologic parameters. Variations like gender (odds ratio [OR] = 1.269, 95% confidence interval [CI] [0.609-2.646]), smoking history (OR = 2.902, 95% CI [1.564-5.385]), AIS grade (grade A) (OR = 6.439, 95% CI [3.334-12.434]), neurological level (C1-C4) (OR = 2.714, 95% CI [1.458-5.066]), and steroid use (OR = 2.983, 95% CI [1.276-6.969]) have a facilitated effect on RC. When we estimated surgery-related affection, only the time of surgery and anterior approach compared with posterior has significant difference in RC (P < .05). Between death and survival group, the aspect of age, non-surgical, CPIS, AIS grade, and BMI have statistically significant difference. Survival analysis reveals significant difference in aforementioned groups. In patients suffering from acute TCSCI, those who are old, have long smoking history, complete spinal cord injury, C1-C4, high CPIS, and fat have high incidence of RC and mortality.

Classification and regression tree model for predicting tracheostomy in patients with traumatic cervical spinal cord injury

PURPOSE

In patients with cervical spinal cord injury (CSCI), respiratory compromise and the need for tracheostomy are common. The purpose of this study was to identify common risk factors for tracheostomy following traumatic CSCI and develop a decision tree for tracheostomy in traumatic CSCI patients without pulmonary function test.

METHODS

Data of 105 trauma patients with CSCI admitted in our institution from April, 2008 to February, 2014 were retrospectively analyzed. Patients who underwent tracheostomy were compared to those who did not. Stepwise logistic regression analysis and classification and regression tree model were used to predict the risk factors for tracheostomy.

RESULTS

Tracheostomy was performed in 20% of patients with traumatic CSCI on median hospital day 4. Patients who underwent tracheostomy tended to be more severely injured (higher Injury Severity Score, lower Glasgow Coma Score, and lower systolic blood pressure on admission) which required more frequent intubation in the emergency room (ER) with a higher rate of complete CSCI compared to those who did not. Upon multiple logistic analysis, Age ≥ 55 years (OR: 6.86, p = 0.037), Car accident (OR: 5.8, p = 0.049), injury above C5 (OR: 28.95, p = 0.009), ISS ≥ 16 (OR: 12.6, p = 0.004), intubation in the ER (OR: 23.87, p = 0.001), and complete CSCI (OR: 62.14, p < 0.001) were significant predictors for the need of tracheostomy after CSCI. These factors can predict whether a new patient needs future tracheostomy with 91.4% accuracy.

CONCLUSIONS

Age ≥ 55 years, injury above C5, ISS ≥ 16, Car accident, intubation in the ER, and complete CSCI were independently associated with tracheostomy after CSCI. CART analysis may provide an intuitive decision tree for tracheostomy.

Ventilatory Management of the Noninjured Lung

This article reviews aspects of mechanical ventilation in patients without lung injury, patients in the perioperative period, and those with neurologic injury or disease including spinal cord injury. Specific emphasis is placed on ventilator strategies, including timing and indications for tracheostomy. Lung protective ventilation, using low tidal volumes and modest levels of positive end-expiratory pressure, should be the default consideration in all patients requiring mechanical ventilatory support. The exception may be the patient with high cervical spinal cord injuries who requires mechanical ventilatory support. There is no consensus on the timing of tracheostomy in patients with neurologic diseases.

Clinical evaluation and airway management for adults with cervical spine instability

Airway management of patients with cervical spine instability may be difficult as a result of immobilization, and may be associated with secondary neurologic injury related to cervical spine motion. Spinal cord instability is most common in patients with trauma, but there are additional congenital and acquired conditions that predispose to subacute cervical spine instability. Patients with suspected instability should receive immobilization during airway management with manual in-line stabilization. The best strategy for airway management is one that applies the technique with the highest likelihood of success on the first attempt and the lowest biomechanical influence on a potentially unstable spine.

Expansion duroplasty improves intraspinal pressure, spinal cord perfusion pressure, and vascular pressure reactivity index in patients with traumatic spinal cord injury: injured spinal cord pressure evaluation study

We recently showed that, after traumatic spinal cord injury (TSCI), laminectomy does not improve intraspinal pressure (ISP), spinal cord perfusion pressure (SCPP), or the vascular pressure reactivity index (sPRx) at the injury site sufficiently because of dural compression. This is an open label, prospective trial comparing combined bony and dural decompression versus laminectomy. Twenty-one patients with acute severe TSCI had re-alignment of the fracture and surgical fixation; 11 had laminectomy alone (laminectomy group) and 10 had laminectomy and duroplasty (laminectomy+duroplasty group). Primary outcomes were magnetic resonance imaging evidence of spinal cord decompression (increase in intradural space, cerebrospinal fluid around the injured cord) and spinal cord physiology (ISP, SCPP, sPRx). The laminectomy and laminectomy+duroplasty groups were well matched. Compared with the laminectomy group, the laminectomy+duroplasty group had greater increase in intradural space at the injury site and more effective decompression of the injured cord. In the laminectomy+duroplasty group, ISP was lower, SCPP higher, and sPRx lower, (i.e., improved vascular pressure reactivity), compared with the laminectomy group. Laminectomy+duroplasty caused cerebrospinal fluid leak that settled with lumbar drain in one patient and pseudomeningocele that resolved completely in five patients. We conclude that, after TSCI, laminectomy+duroplasty improves spinal cord radiological and physiological parameters more effectively than laminectomy alone.

Predictors of the necessity for early tracheostomy in patients with acute cervical spinal cord injury: a 15-year experience

BACKGROUND

The need for mechanical ventilation (MV) after spinal cord injury (SCI) is a risk factor for prolonged critical care. The "purpose" of this study was to identify the level of cervical SCI that requires MV, thereby defining candidates for tracheostomy.

METHODS

Patients with cervical SCI over a 15-year period were reviewed.

RESULTS

One hundred sixty-three patients sustained cervical SCI. Of 76 complete injuries, 91% required MV for greater than 48 hours. By injury level, MV incidence was 100% for C2-4, 91% for C5, 79% for C6, and 80% for C7. Only one quarter of patients with incomplete SCI required MV for greater than 48 hours; Glascow Coma Score and Injury Severity Score were significantly worse compared with patients not requiring MV.

CONCLUSIONS

Factors influencing the decision for tracheostomy in cervical SCI patients include the presence of a complete SCI, anatomic level of injury, Glascow Coma Score, Injury Severity Score, and associated thoracic injury. Patients with complete cervical SCI often require prolonged MV. Conversely, the minority of incomplete SCI required MV; the need for tracheostomy was likely performed for associated injuries. Utilizing identified factors permits a thoughtful approach to tracheostomy in this patient population.