The American Journal of Surgery (2015) 209, 363-368
Clinical Science
Predictors of the necessity for early tracheostomy in patients with acute cervical spinal cord injury: a 15-year experience Teresa S. Jones, M.D.a, Clay Cothren Burlew, M.D.a,*, Jeffrey L. Johnson, M.D.a, Edward Jones, M.D.a, Lucy Z. Kornblith, M.D.a, Walter L. Biffl, M.D.a, Robert T. Stovall, M.D.a, Fredric M. Pieracci, M.D.a, Philip F. Stahel, M.D.b, Ernest E. Moore, M.D.a a
Department of Surgery, Denver Health Medical Center, University of Colorado Denver, 777 Bannock Street, Denver, CO 80204, USA; bDepartment of Orthopedics, Denver Health Medical Center, Denver, CO, USA KEYWORDS: Cervical spine; Spinal cord injury; Tracheostomy; Prolonged ventilation; Trauma
Abstract 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. Ó 2015 Elsevier Inc. All rights reserved.
The authors declare no conflicts of interest. * Corresponding author. Tel.: 11-303-436-6558; fax: 11-303-4366572. E-mail address: [email protected] Manuscript received May 31, 2014; revised manuscript July 10, 2014 0002-9610/$ - see front matter Ó 2015 Elsevier Inc. All rights reserved. http://dx.doi.org/10.1016/j.amjsurg.2014.07.016
Spinal cord injuries account for 12,000 injuries a year, with trauma to the cervical spine accounting for greater than 50% of these injuries.1,2 Cervical spinal cord injury (SCI) causes detrimental alterations in pulmonary function and frequently requires prolonged (greater than 48 hours) mechanical ventilation (MV).3 Complete SCI above the C4 level severely
364 compromises diaphragmatic innervation resulting in the loss of inspiratory effort and permanent ventilator dependence.4,5 Complete injuries at the C5 level and below, as well as incomplete injuries, have more variable clinical presentations and long-term neurologic outcomes; however, these injuries may also require prolonged MV in the acute setting.6–9 Stratifying patients based on their neurologic level of injury and predicting their need for prolonged MV could facilitate the decision for tracheostomy. Tracheostomy is a low-risk procedure that can be rapidly and safely performed at bedside in the appropriate patient.10–12 Early tracheostomy (ET) has been shown to decrease intensive care unit (ICU) length of stay, overall hospital length of stay, and facilitate weaning from MV.13–16 As the benefits of tracheostomy appear most pronounced when performed early during hospitalization, identification of patients who are unlikely to wean from MV would permit ET. Multiple studies to date suffer from combining both level of injury (cervical spine alone vs cervical, thoracic, and lumbar spine) as well as the extent of injury (complete vs incomplete). This muddles the interpretation of the data and makes definitive conclusions difficult. We wanted clarity. This study focuses only on cervical spine injuries and subdivided those injuries into clearer categories for evaluation. The ‘‘purpose’’ of this study was (1) to determine the incidence of tracheostomy in complete versus incomplete cervical SCI, (2) to identify the individual anatomic level of complete cervical SCI that requires prolonged MV, thereby rapidly identifying candidates for tracheostomy, and (3) to identify factors in complete cervical SCI patients which might indicate that patients could be weaned from MV without the need for tracheostomy. We ‘‘hypothesize’’ that all complete cervical SCI should undergo tracheostomy, while incomplete SCI rarely requires prolonged MV and tracheostomy.
Methods All patients diagnosed with a cervical SCI at Denver Health Medical Center from January 1998 to July 2012 were identified and reviewed. Denver Health is a statecertified and American College of Surgeons-verified level I regional trauma center and an integral teaching facility of the University of Colorado School of Medicine. The level and completeness of injury was defined according to the American Spinal Injury Association (ASIA) classification as documented by the neurosurgery and trauma teams.17 Demographics recorded included age, sex, mechanism, Glascow Coma Score (GCS) on arrival, Injury Severity Score (ISS), and Abbreviated Injury Scale (AIS) score. Outcomes including ICU stay, hospital length of stay, and decannulation at the time of discharge were reviewed. Deaths within 48 hours of admission were excluded. The clinical decision for performing a tracheostomy was made jointly by the trauma surgery attending and the surgical critical care attending. Factors suggesting the need for
The American Journal of Surgery, Vol 209, No 2, February 2015 prolonged MV include failure to extubate, diagnosis of acute respiratory distress syndrome (P:F ,200), and failure of spontaneous breathing trials.18,19 The presence of pneumonia was identified with a quantitative culture positive threshold of 105 colony-forming units/mL for a bronchoalveolar lavage (BAL) and clinical evidence defined by clinical pulmonary infection score.20 BAL is not performed routinely in ICU patients without evidence of pneumonia. A positive BAL in the cervical SCI patient has not been considered a mandate for tracheostomy in our clinical practice. Differences between continuous variables were assessed using 2-tailed t test; a P value of less than .05 indicated a significant difference. The Colorado Multi-Institutional Review Board approved this study.
Results During the 15-year study period, 163 patients sustained a traumatic cervical SCI. The majority (78%) of patients were men who suffered blunt (92%) trauma. Mean age of the patient population was 39 6 17 years and mean ISS was 25 6 10. Seventy-six (47%) patients had a complete SCI, while 87 patients sustained an incomplete injury (Table 1).
Complete cervical spinal cord injury Of the 76 patients who sustained a complete cervical SCI, 69 patients required MV; they had injuries at every level of the cervical spine: C2 (4), C3 (6), C4 (21), C5 (20), C6 (10) and C7 (8) (Table 2). Six patients remained on ventilatory support for the duration of their hospitalization but died before tracheostomy. The remaining 63 patients underwent tracheostomy: 37 (58%) patients underwent tracheostomy before hospital day 7 (mean day 5 4.6) and 26 patients underwent tracheostomy on or after hospital day 7 (mean 11.7 days). The mean P:F ratio on the day of tracheostomy was 189 6 76, and there was no significant difference in the P:F ratio on the day of tracheostomy between early and late tracheostomy patients (187 6 87 vs 191 6 62). Of those undergoing tracheostomy, 68% (43/63) of Table 1
Patient demographics stratified by the type of CSCI Complete CSCI (n 5 76)
Age Male sex GCS at admission ISS Blunt mechanism Tracheostomy performed Pneumonia Death
35 65 10 31 67 64
6 15 (83%) 65 69 (86%) (82%)
52 14 (18%)
Incomplete CSCI (n 5 87) 42 63 13 20 84 18
6 16 (72%) 64 67 (97%) (20%)
P value .0076* .0001* .0001*
14 3 (3%)
CSCI 5 cervical spinal cord injury; GCS 5 Glasgow Coma Score; ISS 5 Injury Severity Score. *P value , .05.
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365
Table 2 Demographics and neurologic level of patients with complete spinal cord injury stratified by the need for mechanical ventilation No prolonged MV (n 5 7)
37 6 17 10 6 5 31 6 9
26 6 3 14 6 2 26 6 1
4 6 21 20 10 8
0 0 0 2 3 2
90 80
.10 .03* .11
CSCI 5 cervical spinal cord injury; GCS 5 Glasgow Coma Score; ISS 5 Injury Severity Score; MV 5 mechanical ventilation. *P value , .05.
the patients were diagnosed with pneumonia before tracheostomy placement. Of those undergoing tracheostomy, 29% (18/63) of the patients failed at least one attempt at extubation. In the 27 patients with injuries C4 and above, 4 patients failed extubation and 67% developed pneumonia before tracheostomy. On the day of tracheostomy, these 27 patients had a mean GCS of 10 and their mean P:F ratio was 196 6 81. One patient had an emergent cricothyroidotomy in the emergency department. In the 36 patients with injuries located at C5 and below, 14 patients failed extubation and 69% developed pneumonia before tracheostomy. On the day of tracheostomy, mean GCS was 11 and mean P:F ratio was 182 6 75. Two patients in this group had emergent surgical airways placed after failed intubations. Operative intervention for spine stabilization was employed in the majority of complete cervical SCI; 43 (57%) patients underwent anterior fusion on mean hospital day 4.0. Seven (9%) patients underwent posterior fusion alone. Total hospital days were similar for patients undergoing tracheostomy before day 7 compared with day 7 or later (43 vs 44 days). Seven patients who underwent tracheostomy died during their hospitalization because of causes unrelated to the airway. The incidence of prolonged MV in the 69 patients with complete cervical SCI was as follows: C2 to C4 5 100%, C5 5 91%, C6 5 79%, and C7 5 80% (Fig. 1). Only 5 (8%) complete cervical SCI patients were decannulated at hospital discharge on mean hospital day 51 and mean post-tracheostomy day 43. The level of injury for these patients was C4 (2), C5 (1), C6 (1) and C7 (1). Of the 76 patients who sustained a complete cervical SCI, there were 7 patients who did not require greater than 48 hours of MV (Table 2). One patient remained on ventilatory support for greater than 48 hours and 6 did not require intubation. The level of injury in these patients was located in the lower cervical spine: C5 (2), C6 (3) and C7 (2). All 7 of these patients were discharged to a rehabilitation center without ventilatory support. In
% requiring MV
Age (years) GCS at admission ISS Level of CSCI C2 C3 C4 C5 C6 C7
Prolonged MV (n 5 69)
100
70
60 50 40
30 20 10 0 C-2 C-3 C-4 C-5 C-6 Level of Cervical Spine Injury
C-7
Figure 1 Percentage of patients with complete CSCI requiring prolonged ventilation and undergoing tracheostomy. CSCI 5 cervical spinal cord injury. (For interpretation of the references to color in this Figure, the reader is referred to the web version of this article.)
comparing these patients with those who required MV, patients who were ventilated for 48 hours or less had a significantly higher GCS on arrival to the emergency department (14 6 2 vs 10 6 5, P 5 .03). They also tended to be younger (26 6 3 vs 36 6 16, P 5 .10) with fewer associated injuries (ISS 26 6 2 vs 31 6 9, P 5 .11). The prolonged MV group did have concurrent thoracic injuries (mean chest AIS 5 .86) compared with the group with minimal ventilatory requirements (mean chest AIS 5 0). The median chest AIS for the prolonged MV group was 0 (range 0 to 5); 57 (82.6%) patients had a chest AIS of 0, 1 (1.4%) patient had a chest AIS of 1, 7 (10.1%) patients had a chest AIS of 3, 2 (3.0%) patients had a chest AIS of 4, and 2 (3.0%) patients had a chest AIS of 5. All patients in the minimal ventilatory requirement group had a chest AIS of 0. The median chest AIS between the prolonged MV and the minimal ventilatory group was not statistically significant (Wilcoxon rank P 5 .24). There was no apparent time correlation in those patients managed without prolonged MV; there was an even distribution of these 7 patients over the study period: C5 injuries occurred in 1998 and 2005; C6 injuries in 2001, 2007, and 2007; and C7 injuries in 2008 and 2011.
Incomplete cervical spinal cord injury Of the 87 patients with an incomplete cervical SCI, 18 (21%) required MV for greater than 48 hours; all underwent tracheostomy (Table 3) on hospital day 8.4 6 6. All the patients with incomplete injuries who required tracheostomy had a significantly depressed GCS on arrival (10 6 5 vs 14 6 2, P 5 .0001) and a higher ISS (25 6 10 vs 18 6 5, P 5 .0002) compared with patients who did not require prolonged MV. The patients requiring prolonged MV had concurrent thoracic injuries (mean chest
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The American Journal of Surgery, Vol 209, No 2, February 2015
Table 3 Demographics and neurologic level of patients with incomplete spinal cord injury stratified by the need for mechanical ventilation
Age (years) GCS at admission ISS Level of CSCI C1 C2 C3 C4 C5 C6 C7 C8
Prolonged MV (n 5 18)
No prolonged MV (n 5 69)
P value
41 6 19 10 6 5 25 6 10
42 6 16 14 6 2 18 6 5
.786 .0001* .0002*
0 3 3 2 7 3 0 0
2 5 12 10 17 12 11 0
CSCI 5 cervical spinal cord injury; GCS 5 Glasgow Coma Score; ISS 5 Injury Severity Score; MV 5 mechanical ventilation. *P-value , .05.
AIS 5 1.0) compared with the group with minimal ventilatory requirements (mean chest AIS 5 0). By level of injury, the 18 patients undergoing tracheostomy had incomplete injuries at C2 (3), C3 (2), C4 (2), C5 (7) and C6 (4) (Fig. 2). Before discharge, 2 patients died of other causes and 4 patients were decannulated on mean day 27 and post-tracheostomy day 21. Total ICU stay was 23.5 6 15 days; hospital stay was 32 6 35 days.
Comments Patients who sustain a cervical SCI are at a high risk for respiratory compromise. While tracheostomy has not been
45 40
% requiring MV
35 30 25 20 15 10 5
0 C-2
C-3
C-4
C-5
C-6
C-7
Level of Cervical Spine Injury
Figure 2 Percentage of patients with incomplete CSCI undergoing tracheostomy. CSCI 5 cervical spinal cord injury. (For interpretation of the references to color in this Figure, the reader is referred to the web version of this article.)
shown to consistently improve rates of ventilator-associated pneumonia, it has been associated with decreased ventilator days and ICU days and appears to facilitate weaning.12,21,22 There is little debate over the management of patients with complete cervical SCI at C4 or above. However, the need for prolonged MV and the role of tracheostomy in SCI below C4 remains an area of active investigation. Hassid et al6 evaluated the need for definitive airway control in patients with lower cervical spine injuries, between C5–T1, and found that 91% were initially intubated and 75% required a tracheostomy. Only 11 (9%) patients in that study were never intubated and just one survived to discharge. Como et al8 reported that all patients with complete C5 injuries required permanent ventilation, while that 7 of 14 (50%) patients with complete injuries at C6 and C7 were ventilator dependent at discharge. Harrop et al9 also reported that lower injuries in the cervical spine required less intervention; in their study, only 33% of patients with C6 and C7 injuries required tracheostomy. One confounder in the review of the SCI literature is the delineation between complete and incomplete spinal cord injuries, with the 2 groups often combined during statistical analysis23; at times, all levels of SCI, including thoracic and lumbar injuries, are grouped during analysis. Understandably, the lumping of such disparate groups can alter the rates of reported need for MV and subsequent tracheostomy; incomplete injuries are a separate subset compared with complete injuries, as noted in the ASIA classification. When reviewing the literature, this tendency to combine all spinal cord injuries often confuses the outcomes and associated recommendations.24 When reviewing our own experience with cervical SCI, we separated these 2 distinct subsets of patientsdcomplete versus incomplete spinal cord injuries. Patients with thoracic and lumbar spine injuries were purposefully not included in the study. Additionally, we subdivided complete cervical SCI patients at each level of injury to determine if there was a significant difference in need for tracheostomy based on distinct anatomic level. With the ease and safety of bedside tracheostomy,10 our goal was to identify those cervical SCI patients with a high percentage of prolonged MV, permitting timely tracheostomy. To our knowledge, our study is the largest singleinstitution analysis of cervical SCI to date. This analysis supports ET in the vast majority of patients with complete cervical SCI. Although the accompanying figures report the specific percentage of patients undergoing tracheostomy at each level of injury, over 90% of all patients underwent tracheostomy. There was a clear predominance of pulmonary failure in this group with the majority of patients demonstrating both impaired ventilation with P:F ratios less than 200 and pneumonia before their tracheostomy. We did try to liberate a significant portion of these patients from the ventilator, with a failed extubation rate of 29%. Over the long term, only 5 patients were decannulated and these decannulations occurred almost 2 months after initial injury admission. Although ET in these patients is optimal, precise
T.S. Jones et al.
Tracheostomy following spinal cord injury
timing of tracheostomy will be driven by the patient’s physiology and necessary procedures. For example, high positive end expiratory pressure or Fi02 ventilatory requirements may cause one to delay performing a tracheostomy until hypoxemia improves. Additionally, the historical mantra of delaying tracheostomy in patients undergoing anterior fusion to prevent wound complications remains controversial. In concert with recent literature suggesting there is no increase in infectious complications in patients undergoing ET following instrumented fusion,25 over half of our patient population underwent anterior fusion with tracheostomy thereafter. So how do we predict which complete cervical SCI patient should not undergo tracheostomy? Others have suggested that not all patients with cervical spine injuries should undergo ET.24 Although this study is difficult to interpret because of mixing of patient populations, the authors’ suggestion should make the practicing clinician question the use of ‘‘automatic’’ tracheostomy for all patients with cervical SCI. In an attempt to elucidate the factors involved, we analyzed the small percentage of patients with complete cervical SCI that did not require prolonged MV. The only significant difference between the 2 groups (prolonged MV vs no MV) was admission GCS. Although not significant on statistical analysis, patients not requiring ventilatory support were younger and had fewer injuries, particularly thoracic injuries. These findings have been substantiated in other series as predictive variables not requiring prolonged MV.22 Combining our results with other reports in the literature7,16,22 might identify the select, complete cervical SCI patients who may escape the need for prolonged MV. A patient with a near-normal GCS, a complete cervical SCI at C5 or below, plus no evidence of thoracic injury or minimal-associated other injuries may avoid ventilatory support. Finally, the incomplete cervical SCI patient population remains more heterogeneous, with variable mobility from ASIA B to D scores and clinical syndromes including Brown–Sequard. Tracheostomy rates in our population for incomplete spinal cord injuries remain low at approximately 20%, which is consistent with previous reports.8 In our experience, all patients who required MV beyond 48 hours did undergo tracheostomy. Delineating this correlation may lead to earlier tracheostomy in this population. The decision for tracheostomy in this group was likely related to associated injuries as patients had a significantly lower GCS and a higher ISS compared with patients who did not require prolonged MV. Clinical judgment, therefore, is required for each patient as tracheostomy may be required at every neurologic level. There are limitations inherent to any retrospective review. Although one of the largest in the literature, our analysis may lack significance because of small sample size. The decision for tracheostomy was determined by the attending trauma surgeon and surgical intensivist without a predefined algorithm. The development of a protocol is in process and is bolstered by this analysis.
367
Conclusions All SCI patients are at high risk for prolonged MV. Patients with complete cervical SCI above C5 require MV and should undergo ET. The vast majority of patients with complete cervical SCI at or below C5 will also require prolonged MV and should be evaluated for ET. Extubation attempts and avoidance of tracheostomy may be considered for those patients with a complete cervical SCI at C5 or below with near-normal GCS plus no evidence of thoracic injury or minimal-associated other injuries. Patients with incomplete spinal cord injuries have highly variable presentations with the minority undergoing tracheostomy; all patients requiring MV beyond 48 hours underwent tracheostomy. Care should be individualized based on patient physiology and associated intracranial and thoracic injuries.
References 1. National Spinal Cord Injury Statistical Center. Available at: http:// www.spinalcord.uab.edu. Accessed April 24, 2014. 2. Bawa M, Fayssoux R. Vertebrae and spinal cord. In: Mattox KL, Moore EE, Feliciano DV, editors. Trauma. 7th ed. New York: McGraw-Hill; 2012. 3. Ledsome JR, Sharp JM. Pulmonary function in acute cervical cord injury. Am Rev Respir Dis 1981;l24:41–4. 4. Schmitt J, Midha M, McKenzie N. Medical complications of spinal cord disease. Neurol Clin 1991;9:779–83. 5. Wicks AB, Menter RR. Long-term outlook in quadriplegic patients with initial ventilator dependency. Chest 1986;90:406–41. 6. Hassid V, Schinco MA, Tepas JJ, et al. Definitive establishment of airway control is critical for optimal outcome in lower cervical spinal cord injury. J Trauma 2008;65:1328–32. 7. Branco BC, Plurad D, Green DJ, et al. Incidence and clinical predictors for tracheostomy after cervical spinal cord injury: a National Trauma Databank review. J Trauma 2011;70:111–5. 8. Como JJ, Sutton ER, McCunn M, et al. Characterizing the need for mechanical ventilation following cervical spinal cord injury with neurologic deficit. J Trauma 2005;59:912–6. 9. Harrop JS, Sharan AD, Scheid Jr EH, et al. Tracheostomy placement in patients with complete cervical spinal cord injuries: American Spinal Injury Association Grade A. J Neurosurg 2004;100(1 Suppl Spine): 20–3. 10. Kornblith LZ, Burlew CC, Moore EE, et al. One thousand bedside percutaneous tracheostomies in the surgical intensive care unit: time to change the gold standard. J Am Coll Surg 2011;212:163–70. 11. Zagli G, Linden M, Spina R, et al. Early tracheostomy in intensive care unit: a retrospective study of 506 cases of video-guided Ciaglia Blue Rhino tracheostomies. J Trauma 2010;68:368–72. 12. Milanchi S, Magner D, Wilson MT, et al. Percutaneous tracheostomy in neurosurgical patients with intracranial pressure monitoring is safe. J Trauma 2008;65:73–9. 13. Brook AD, Sherman G, Malen J, et al. Early versus late tracheostomy in patients who require prolonged mechanical ventilation. Am J Crit Care 2000;9:352–9. 14. Terragni PP, Antonelli M, Fumagalli R, et al. Early vs late tracheotomy for prevention of pneumonia in mechanically ventilated adult ICU patients. JAMA 2010;303:1483–9. 15. Romero J, Vari A, Gambarrutta C, et al. Tracheostomy timing in traumatic spinal cord injury. Eur Spine J 2009;18:1452–7. 16. Leelapattana P, Fleming JC, Gurr KR, et al. Predicting the need for tracheostomy in patients with cervical spinal cord injury. J Trauma Acute Care Surg 2012;73:880–4.
368 17. Kirshblum SC, Burns SP, Biering-Sorensen F, et al. International standard for neurological classification of spinal cord injuries. J Spinal Cord Med 2011;34:535–46. 18. The ARDS Definition Task Force, Ranieri VM, Rubenfeld GD, Thompson BT, et al. Acute respiratory distress syndrome: the Berlin Definition. JAMA 2012;307:2526–33. 19. McIntyre NR. Evidence-based assessments in the ventilator discontinuation process. Respir Care 2012;57:1611–8. 20. Pugin J, Auckenthaler R, Mili N, et al. Diagnosis for ventilatorassociated pneumonia by bacteriologic analysis of bronchoscopic and nonbronchoscopic ‘‘blind’’ bronchoalveolar lavage fluid. Am Rev Respir Dis 1991;143:1121–9. 21. Arabi YM, Alhashemi JA, Tamim HM, et al. The impact of time to tracheostomy on mechanical ventilation duration length of stay and
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mortality in intensive care unit patients. J Crit Care 2009;24: 435–40. Goettler CE, Fugo JR, Bard MR, et al. Predicting the need for early tracheostomy: a multifactorial analysis of 992 intubated trauma patients. J Trauma 2006;60:991–6. Call MS, Kutcher ME, Izenberg RA, et al. Spinal cord injury: outcomes of ventilatory weaning and extubation. J Trauma 2011;71:1673–9. Kornblith L, Kutcher ME, Callcut RA, et al. Mechanical ventilation weaning and extubation after spinal cord injury: a Western Trauma Association multicenter study. J Trauma Acute Care Surg 2013;75: 1060–9; discussion, 1069–70. Babu R, Owens TR, Thomas S, et al. Timing of tracheostomy after anterior cervical spine fixation. J Trauma Acute Care Surg 2013;74: 961–6.
Clinical Science
Predictors of the necessity for early tracheostomy in patients with acute cervical spinal cord injury: a 15-year experience Teresa S. Jones, M.D.a, Clay Cothren Burlew, M.D.a,*, Jeffrey L. Johnson, M.D.a, Edward Jones, M.D.a, Lucy Z. Kornblith, M.D.a, Walter L. Biffl, M.D.a, Robert T. Stovall, M.D.a, Fredric M. Pieracci, M.D.a, Philip F. Stahel, M.D.b, Ernest E. Moore, M.D.a a
Department of Surgery, Denver Health Medical Center, University of Colorado Denver, 777 Bannock Street, Denver, CO 80204, USA; bDepartment of Orthopedics, Denver Health Medical Center, Denver, CO, USA KEYWORDS: Cervical spine; Spinal cord injury; Tracheostomy; Prolonged ventilation; Trauma
Abstract 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. Ó 2015 Elsevier Inc. All rights reserved.
The authors declare no conflicts of interest. * Corresponding author. Tel.: 11-303-436-6558; fax: 11-303-4366572. E-mail address: [email protected] Manuscript received May 31, 2014; revised manuscript July 10, 2014 0002-9610/$ - see front matter Ó 2015 Elsevier Inc. All rights reserved. http://dx.doi.org/10.1016/j.amjsurg.2014.07.016
Spinal cord injuries account for 12,000 injuries a year, with trauma to the cervical spine accounting for greater than 50% of these injuries.1,2 Cervical spinal cord injury (SCI) causes detrimental alterations in pulmonary function and frequently requires prolonged (greater than 48 hours) mechanical ventilation (MV).3 Complete SCI above the C4 level severely
364 compromises diaphragmatic innervation resulting in the loss of inspiratory effort and permanent ventilator dependence.4,5 Complete injuries at the C5 level and below, as well as incomplete injuries, have more variable clinical presentations and long-term neurologic outcomes; however, these injuries may also require prolonged MV in the acute setting.6–9 Stratifying patients based on their neurologic level of injury and predicting their need for prolonged MV could facilitate the decision for tracheostomy. Tracheostomy is a low-risk procedure that can be rapidly and safely performed at bedside in the appropriate patient.10–12 Early tracheostomy (ET) has been shown to decrease intensive care unit (ICU) length of stay, overall hospital length of stay, and facilitate weaning from MV.13–16 As the benefits of tracheostomy appear most pronounced when performed early during hospitalization, identification of patients who are unlikely to wean from MV would permit ET. Multiple studies to date suffer from combining both level of injury (cervical spine alone vs cervical, thoracic, and lumbar spine) as well as the extent of injury (complete vs incomplete). This muddles the interpretation of the data and makes definitive conclusions difficult. We wanted clarity. This study focuses only on cervical spine injuries and subdivided those injuries into clearer categories for evaluation. The ‘‘purpose’’ of this study was (1) to determine the incidence of tracheostomy in complete versus incomplete cervical SCI, (2) to identify the individual anatomic level of complete cervical SCI that requires prolonged MV, thereby rapidly identifying candidates for tracheostomy, and (3) to identify factors in complete cervical SCI patients which might indicate that patients could be weaned from MV without the need for tracheostomy. We ‘‘hypothesize’’ that all complete cervical SCI should undergo tracheostomy, while incomplete SCI rarely requires prolonged MV and tracheostomy.
Methods All patients diagnosed with a cervical SCI at Denver Health Medical Center from January 1998 to July 2012 were identified and reviewed. Denver Health is a statecertified and American College of Surgeons-verified level I regional trauma center and an integral teaching facility of the University of Colorado School of Medicine. The level and completeness of injury was defined according to the American Spinal Injury Association (ASIA) classification as documented by the neurosurgery and trauma teams.17 Demographics recorded included age, sex, mechanism, Glascow Coma Score (GCS) on arrival, Injury Severity Score (ISS), and Abbreviated Injury Scale (AIS) score. Outcomes including ICU stay, hospital length of stay, and decannulation at the time of discharge were reviewed. Deaths within 48 hours of admission were excluded. The clinical decision for performing a tracheostomy was made jointly by the trauma surgery attending and the surgical critical care attending. Factors suggesting the need for
The American Journal of Surgery, Vol 209, No 2, February 2015 prolonged MV include failure to extubate, diagnosis of acute respiratory distress syndrome (P:F ,200), and failure of spontaneous breathing trials.18,19 The presence of pneumonia was identified with a quantitative culture positive threshold of 105 colony-forming units/mL for a bronchoalveolar lavage (BAL) and clinical evidence defined by clinical pulmonary infection score.20 BAL is not performed routinely in ICU patients without evidence of pneumonia. A positive BAL in the cervical SCI patient has not been considered a mandate for tracheostomy in our clinical practice. Differences between continuous variables were assessed using 2-tailed t test; a P value of less than .05 indicated a significant difference. The Colorado Multi-Institutional Review Board approved this study.
Results During the 15-year study period, 163 patients sustained a traumatic cervical SCI. The majority (78%) of patients were men who suffered blunt (92%) trauma. Mean age of the patient population was 39 6 17 years and mean ISS was 25 6 10. Seventy-six (47%) patients had a complete SCI, while 87 patients sustained an incomplete injury (Table 1).
Complete cervical spinal cord injury Of the 76 patients who sustained a complete cervical SCI, 69 patients required MV; they had injuries at every level of the cervical spine: C2 (4), C3 (6), C4 (21), C5 (20), C6 (10) and C7 (8) (Table 2). Six patients remained on ventilatory support for the duration of their hospitalization but died before tracheostomy. The remaining 63 patients underwent tracheostomy: 37 (58%) patients underwent tracheostomy before hospital day 7 (mean day 5 4.6) and 26 patients underwent tracheostomy on or after hospital day 7 (mean 11.7 days). The mean P:F ratio on the day of tracheostomy was 189 6 76, and there was no significant difference in the P:F ratio on the day of tracheostomy between early and late tracheostomy patients (187 6 87 vs 191 6 62). Of those undergoing tracheostomy, 68% (43/63) of Table 1
Patient demographics stratified by the type of CSCI Complete CSCI (n 5 76)
Age Male sex GCS at admission ISS Blunt mechanism Tracheostomy performed Pneumonia Death
35 65 10 31 67 64
6 15 (83%) 65 69 (86%) (82%)
52 14 (18%)
Incomplete CSCI (n 5 87) 42 63 13 20 84 18
6 16 (72%) 64 67 (97%) (20%)
P value .0076* .0001* .0001*
14 3 (3%)
CSCI 5 cervical spinal cord injury; GCS 5 Glasgow Coma Score; ISS 5 Injury Severity Score. *P value , .05.
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Table 2 Demographics and neurologic level of patients with complete spinal cord injury stratified by the need for mechanical ventilation No prolonged MV (n 5 7)
37 6 17 10 6 5 31 6 9
26 6 3 14 6 2 26 6 1
4 6 21 20 10 8
0 0 0 2 3 2
90 80
.10 .03* .11
CSCI 5 cervical spinal cord injury; GCS 5 Glasgow Coma Score; ISS 5 Injury Severity Score; MV 5 mechanical ventilation. *P value , .05.
the patients were diagnosed with pneumonia before tracheostomy placement. Of those undergoing tracheostomy, 29% (18/63) of the patients failed at least one attempt at extubation. In the 27 patients with injuries C4 and above, 4 patients failed extubation and 67% developed pneumonia before tracheostomy. On the day of tracheostomy, these 27 patients had a mean GCS of 10 and their mean P:F ratio was 196 6 81. One patient had an emergent cricothyroidotomy in the emergency department. In the 36 patients with injuries located at C5 and below, 14 patients failed extubation and 69% developed pneumonia before tracheostomy. On the day of tracheostomy, mean GCS was 11 and mean P:F ratio was 182 6 75. Two patients in this group had emergent surgical airways placed after failed intubations. Operative intervention for spine stabilization was employed in the majority of complete cervical SCI; 43 (57%) patients underwent anterior fusion on mean hospital day 4.0. Seven (9%) patients underwent posterior fusion alone. Total hospital days were similar for patients undergoing tracheostomy before day 7 compared with day 7 or later (43 vs 44 days). Seven patients who underwent tracheostomy died during their hospitalization because of causes unrelated to the airway. The incidence of prolonged MV in the 69 patients with complete cervical SCI was as follows: C2 to C4 5 100%, C5 5 91%, C6 5 79%, and C7 5 80% (Fig. 1). Only 5 (8%) complete cervical SCI patients were decannulated at hospital discharge on mean hospital day 51 and mean post-tracheostomy day 43. The level of injury for these patients was C4 (2), C5 (1), C6 (1) and C7 (1). Of the 76 patients who sustained a complete cervical SCI, there were 7 patients who did not require greater than 48 hours of MV (Table 2). One patient remained on ventilatory support for greater than 48 hours and 6 did not require intubation. The level of injury in these patients was located in the lower cervical spine: C5 (2), C6 (3) and C7 (2). All 7 of these patients were discharged to a rehabilitation center without ventilatory support. In
% requiring MV
Age (years) GCS at admission ISS Level of CSCI C2 C3 C4 C5 C6 C7
Prolonged MV (n 5 69)
100
70
60 50 40
30 20 10 0 C-2 C-3 C-4 C-5 C-6 Level of Cervical Spine Injury
C-7
Figure 1 Percentage of patients with complete CSCI requiring prolonged ventilation and undergoing tracheostomy. CSCI 5 cervical spinal cord injury. (For interpretation of the references to color in this Figure, the reader is referred to the web version of this article.)
comparing these patients with those who required MV, patients who were ventilated for 48 hours or less had a significantly higher GCS on arrival to the emergency department (14 6 2 vs 10 6 5, P 5 .03). They also tended to be younger (26 6 3 vs 36 6 16, P 5 .10) with fewer associated injuries (ISS 26 6 2 vs 31 6 9, P 5 .11). The prolonged MV group did have concurrent thoracic injuries (mean chest AIS 5 .86) compared with the group with minimal ventilatory requirements (mean chest AIS 5 0). The median chest AIS for the prolonged MV group was 0 (range 0 to 5); 57 (82.6%) patients had a chest AIS of 0, 1 (1.4%) patient had a chest AIS of 1, 7 (10.1%) patients had a chest AIS of 3, 2 (3.0%) patients had a chest AIS of 4, and 2 (3.0%) patients had a chest AIS of 5. All patients in the minimal ventilatory requirement group had a chest AIS of 0. The median chest AIS between the prolonged MV and the minimal ventilatory group was not statistically significant (Wilcoxon rank P 5 .24). There was no apparent time correlation in those patients managed without prolonged MV; there was an even distribution of these 7 patients over the study period: C5 injuries occurred in 1998 and 2005; C6 injuries in 2001, 2007, and 2007; and C7 injuries in 2008 and 2011.
Incomplete cervical spinal cord injury Of the 87 patients with an incomplete cervical SCI, 18 (21%) required MV for greater than 48 hours; all underwent tracheostomy (Table 3) on hospital day 8.4 6 6. All the patients with incomplete injuries who required tracheostomy had a significantly depressed GCS on arrival (10 6 5 vs 14 6 2, P 5 .0001) and a higher ISS (25 6 10 vs 18 6 5, P 5 .0002) compared with patients who did not require prolonged MV. The patients requiring prolonged MV had concurrent thoracic injuries (mean chest
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Table 3 Demographics and neurologic level of patients with incomplete spinal cord injury stratified by the need for mechanical ventilation
Age (years) GCS at admission ISS Level of CSCI C1 C2 C3 C4 C5 C6 C7 C8
Prolonged MV (n 5 18)
No prolonged MV (n 5 69)
P value
41 6 19 10 6 5 25 6 10
42 6 16 14 6 2 18 6 5
.786 .0001* .0002*
0 3 3 2 7 3 0 0
2 5 12 10 17 12 11 0
CSCI 5 cervical spinal cord injury; GCS 5 Glasgow Coma Score; ISS 5 Injury Severity Score; MV 5 mechanical ventilation. *P-value , .05.
AIS 5 1.0) compared with the group with minimal ventilatory requirements (mean chest AIS 5 0). By level of injury, the 18 patients undergoing tracheostomy had incomplete injuries at C2 (3), C3 (2), C4 (2), C5 (7) and C6 (4) (Fig. 2). Before discharge, 2 patients died of other causes and 4 patients were decannulated on mean day 27 and post-tracheostomy day 21. Total ICU stay was 23.5 6 15 days; hospital stay was 32 6 35 days.
Comments Patients who sustain a cervical SCI are at a high risk for respiratory compromise. While tracheostomy has not been
45 40
% requiring MV
35 30 25 20 15 10 5
0 C-2
C-3
C-4
C-5
C-6
C-7
Level of Cervical Spine Injury
Figure 2 Percentage of patients with incomplete CSCI undergoing tracheostomy. CSCI 5 cervical spinal cord injury. (For interpretation of the references to color in this Figure, the reader is referred to the web version of this article.)
shown to consistently improve rates of ventilator-associated pneumonia, it has been associated with decreased ventilator days and ICU days and appears to facilitate weaning.12,21,22 There is little debate over the management of patients with complete cervical SCI at C4 or above. However, the need for prolonged MV and the role of tracheostomy in SCI below C4 remains an area of active investigation. Hassid et al6 evaluated the need for definitive airway control in patients with lower cervical spine injuries, between C5–T1, and found that 91% were initially intubated and 75% required a tracheostomy. Only 11 (9%) patients in that study were never intubated and just one survived to discharge. Como et al8 reported that all patients with complete C5 injuries required permanent ventilation, while that 7 of 14 (50%) patients with complete injuries at C6 and C7 were ventilator dependent at discharge. Harrop et al9 also reported that lower injuries in the cervical spine required less intervention; in their study, only 33% of patients with C6 and C7 injuries required tracheostomy. One confounder in the review of the SCI literature is the delineation between complete and incomplete spinal cord injuries, with the 2 groups often combined during statistical analysis23; at times, all levels of SCI, including thoracic and lumbar injuries, are grouped during analysis. Understandably, the lumping of such disparate groups can alter the rates of reported need for MV and subsequent tracheostomy; incomplete injuries are a separate subset compared with complete injuries, as noted in the ASIA classification. When reviewing the literature, this tendency to combine all spinal cord injuries often confuses the outcomes and associated recommendations.24 When reviewing our own experience with cervical SCI, we separated these 2 distinct subsets of patientsdcomplete versus incomplete spinal cord injuries. Patients with thoracic and lumbar spine injuries were purposefully not included in the study. Additionally, we subdivided complete cervical SCI patients at each level of injury to determine if there was a significant difference in need for tracheostomy based on distinct anatomic level. With the ease and safety of bedside tracheostomy,10 our goal was to identify those cervical SCI patients with a high percentage of prolonged MV, permitting timely tracheostomy. To our knowledge, our study is the largest singleinstitution analysis of cervical SCI to date. This analysis supports ET in the vast majority of patients with complete cervical SCI. Although the accompanying figures report the specific percentage of patients undergoing tracheostomy at each level of injury, over 90% of all patients underwent tracheostomy. There was a clear predominance of pulmonary failure in this group with the majority of patients demonstrating both impaired ventilation with P:F ratios less than 200 and pneumonia before their tracheostomy. We did try to liberate a significant portion of these patients from the ventilator, with a failed extubation rate of 29%. Over the long term, only 5 patients were decannulated and these decannulations occurred almost 2 months after initial injury admission. Although ET in these patients is optimal, precise
T.S. Jones et al.
Tracheostomy following spinal cord injury
timing of tracheostomy will be driven by the patient’s physiology and necessary procedures. For example, high positive end expiratory pressure or Fi02 ventilatory requirements may cause one to delay performing a tracheostomy until hypoxemia improves. Additionally, the historical mantra of delaying tracheostomy in patients undergoing anterior fusion to prevent wound complications remains controversial. In concert with recent literature suggesting there is no increase in infectious complications in patients undergoing ET following instrumented fusion,25 over half of our patient population underwent anterior fusion with tracheostomy thereafter. So how do we predict which complete cervical SCI patient should not undergo tracheostomy? Others have suggested that not all patients with cervical spine injuries should undergo ET.24 Although this study is difficult to interpret because of mixing of patient populations, the authors’ suggestion should make the practicing clinician question the use of ‘‘automatic’’ tracheostomy for all patients with cervical SCI. In an attempt to elucidate the factors involved, we analyzed the small percentage of patients with complete cervical SCI that did not require prolonged MV. The only significant difference between the 2 groups (prolonged MV vs no MV) was admission GCS. Although not significant on statistical analysis, patients not requiring ventilatory support were younger and had fewer injuries, particularly thoracic injuries. These findings have been substantiated in other series as predictive variables not requiring prolonged MV.22 Combining our results with other reports in the literature7,16,22 might identify the select, complete cervical SCI patients who may escape the need for prolonged MV. A patient with a near-normal GCS, a complete cervical SCI at C5 or below, plus no evidence of thoracic injury or minimal-associated other injuries may avoid ventilatory support. Finally, the incomplete cervical SCI patient population remains more heterogeneous, with variable mobility from ASIA B to D scores and clinical syndromes including Brown–Sequard. Tracheostomy rates in our population for incomplete spinal cord injuries remain low at approximately 20%, which is consistent with previous reports.8 In our experience, all patients who required MV beyond 48 hours did undergo tracheostomy. Delineating this correlation may lead to earlier tracheostomy in this population. The decision for tracheostomy in this group was likely related to associated injuries as patients had a significantly lower GCS and a higher ISS compared with patients who did not require prolonged MV. Clinical judgment, therefore, is required for each patient as tracheostomy may be required at every neurologic level. There are limitations inherent to any retrospective review. Although one of the largest in the literature, our analysis may lack significance because of small sample size. The decision for tracheostomy was determined by the attending trauma surgeon and surgical intensivist without a predefined algorithm. The development of a protocol is in process and is bolstered by this analysis.
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Conclusions All SCI patients are at high risk for prolonged MV. Patients with complete cervical SCI above C5 require MV and should undergo ET. The vast majority of patients with complete cervical SCI at or below C5 will also require prolonged MV and should be evaluated for ET. Extubation attempts and avoidance of tracheostomy may be considered for those patients with a complete cervical SCI at C5 or below with near-normal GCS plus no evidence of thoracic injury or minimal-associated other injuries. Patients with incomplete spinal cord injuries have highly variable presentations with the minority undergoing tracheostomy; all patients requiring MV beyond 48 hours underwent tracheostomy. Care should be individualized based on patient physiology and associated intracranial and thoracic injuries.
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