Sleep apnea and cervical spine pathology

Does Anterior Cervical Spine Surgery Increase the Likelihood of Developing Obstructive Sleep Apnea? A Pearldiver Study

OBJECTIVES

Literature is sparse on the development of obstructive sleep apnea (OSA) after anterior cervical spine surgery and includes few case reports. Our objective is to evaluate the role of anterior cervical spine surgery as a risk factor for developing OSA.

METHODS

A retrospective cohort study was performed utilizing the M157 subset of the PearlDiver national database. Two matched cohorts of patients were identified based on anterior cervical spine surgery using CPT codes. ICD-9 and 10 was used to identify patients who developed OSA within one year time frame in both the cohorts. Relative risk of OSA was calculated for the study and risk factors for developing OSA in the cohort of anterior cervical surgery were evaluated using logistic regression.

RESULTS

The 2 cohorts contained 277,475 patients each. The 1-year incidence rate of OSA in those who undergo anterior cervical spine surgery is 3.5% and is 3.1% in the control group. The relative risk of OSA in the surgery group is 1.13 times compared to the control. Multilevel cervical spine surgery and surgery performed for spondylosis had a higher risk of developing OSA.

CONCLUSIONS

Anterior cervical spine surgery is associated with an increased risk of developing OSA within one year of surgery. Timely diagnosis and management of OSA in patients who underwent anterior cervical spine surgery can help prevent morbidity and improve quality of life (QOL).

Correlation between craniocervical posture and upper airway dimension in patients with bilateral anterior disc displacement

OBJECTIVE

To investigate the relationship between upper airway dimension and craniocervical posture in adult patients with bilateral anterior disc displacement and to provide some references for clinical diagnosis and plan formulation in orthodontics.

METHODS

Based on RDC/TMD (Research Diagnostic Criteria for Temporomandibular Disorder), 98 Patients were divided into three groups by two experienced TMJ (Temporomandibular Joint) specialists: bilateral disc normal position group (BN), bilateral anterior disc displacement with reduction group (ADDWR) and bilateral anterior disc displacement without reduction group (ADDWoR). Inter-group comparison and correlation analysis were performed after 11 craniocervical posture and 15 upper airway dimension measurements finished with Dolphin and Uceph software in Two or Three-dimensional.

RESULTS

Anterior disc displacement often accompanied with extension of craniocervical posture, as ADDWR and ADDWoR groups have significantly higher cervical curvature and inclination than BN group (P < 0.05). Simultaneously anterior disc displacement often associated with constrained upper airway dimension for the total and each segment upper airway volume were significantly smaller in ADDWR and ADDWoR than BN group (P < 0.05). Correlation analysis revealed that C0-C1 (the distance from the base of the occipital bone (C0) to the posterior arch of the atlas (C1)) is significantly related to the total and each segment upper airway volume reduction (P < 0.05).

CONCLUSION

There exists markedly close correlation between anterior disc displacement and craniocervical posture forward extension, which may be physiologically adaptive cervical extension to keep oropharyngeal airway unobstructed as upper airway dimension constrained by anterior disc displacement.

CLINICAL RELEVANCE

These findings allow us to infer the potential consequences if the treatment of anterior disc displacement would result in an improvement of intervertebral relationships and upper airway constraint.

A new radiological parameter as a predictor of dysphagia based on oro-pharyngeal stenosis in a cohort of pediatric patients undergoing mal-reduced C1-2 pedicle screw fixation

PURPOSE

C1 pedicle screw technique showed further advantages since it avoids the negative results from the sacrificed range of motion of the atlantooccipital joint compared to the occipitocervical fusion. However, some intractable complications are unavoidable. In the pediatric population, dysphagia after the atlantoaxial fixation can be accidentally serious. We aimed to determine the incidence of dysphagia in the pediatric population's cohort and its radiological predictor.

METHODS

Between January 2010 and August 2018, this retrospective study included 42 pediatric patients with atlantoaxial dislocation due to trauma. They were followed up with an average duration of 8 years (range 5-18 years). Twenty-seven were males and 15 females with a mean age of 8.2 years (range 5-15 years) when undergoing operations. Patients were classified according to the presence of postoperative dysphagia according to the Bazaz dysphagia grading scale. The measurements, including pre- and postoperative CVT/NSL, O-C2, and C2-C7 sagittal angles, were performed.

RESULTS

26.2% of the patients (11/42) experienced postoperative dysphagia. A significant difference in the postoperative CVT/NSL (115.2 ± 13.2 vs.134.8 ± 17.3, P = 0.002), ΔCVT/NSL (7.0 ± 11.2 vs. 20.3 ± 10.5, P = 0.001), ΔO-C2 (- 3.2 ± 5.8 vs. 2.1 ± 5.1, P = 0.026), postoperative nPAS (9.4 ± 3.7 vs. 12.6 ± 4.2, P = 0.031) and ΔPAS (- 1.5 ± 4.1 vs. 2.0 ± 3.5, P = 0.010) between dysphagia group and non-dysphagia group were found. Adjustment for age, gender, and BMI, the multivariate logistic analysis showed that ΔCVT/NSL < 8.35° (OR = 5.23; 95% CI 4.97-5.50; P = 0.001) and ΔO-C2 (OR = 3.34; 95% CI 3.17-3.51; P = 0.001) remained associated with the occurrence of the swallowing problems.

CONCLUSION

In comparison with ΔO-C2, ΔCVT/NSL might better predict postoperative dysphagia in children.

LEVEL OF EVIDENCE I

Diagnostic: individual cross-sectional studies with consistently applied reference standard and blinding.

The Impact of Obstructive Sleep Apnea on Clinical, Perioperative, and Cost Outcomes in Patients Who Underwent Posterior Cervical Decompression and Fusion: A Single-Center Retrospective Analysis From 2008 to 2016

BACKGROUND

Obstructive sleep apnea (OSA) is a pervasive problem that can result in diminished neurocognitive performance, increased risk of all-cause mortality, and significant cardiovascular disease. While previous studies have examined risk factors that influence outcomes following cervical fusion procedures, to our knowledge, no study has examined the cost or outcome profiles for posterior cervical decompression and fusion (PCDF) procedures in patients with OSA.

METHODS

All cases at a single institution between 2008 and 2016 involving a PCDF were included. The primary outcome was prolonged extubation, defined as an extubation that took place outside of the operating room. Secondary outcomes included admission to the intensive care unit (ICU), complications, extended hospitalization, nonhome discharge, readmission within 30 and 90 days, emergency room visit within 30 and 90 days, and higher total costs.

RESULTS

We reviewed 1191 PCDF cases, of which 93 patients (7.81%) had a history of OSA. At the univariate level, patients with OSA had higher rates of ICU admissions (33.3% vs 16.8%, P < 0.0001), total complications (29.0% vs 19.0%, P = 0.0202), and respiratory complications (12.9% vs 6.6%, P = 0.0217). Multivariate regression analyses revealed no difference in the odds of a prolonged extubation (P = 0.4773) and showed that history of OSA was not predictive of higher costs. However, a significant difference was observed in the odds of having an ICU admission (P = 0.0046).

CONCLUSION

While patients with sleep apnea may be more likely to be admitted to the ICU postoperatively, OSA status a lone is not a risk factor for poor primary and secondary clinical outcomes following posterior cervical fusion procedures.

CLINICAL RELEVANCE

Various deformities of the cervical spine can exert extraluminal forces that partially collapse or obstruct the airway, thereby predisposing patients to OSA; however, no study has examined the cost or outcome profiles for PCDF procedures in patients with OSA. Therefore, this investigation highlights the ways in which OSA influences the risks, outcomes, and costs following PCDF using medical data from an institutional registry.

LEVEL OF EVIDENCE: 3

Three-dimensional craniofacial characteristics associated with obstructive sleep apnea severity and treatment outcomes

OBJECTIVES

This study aims to assess craniofacial dimensions in obstructive sleep apnea (OSA) patients treated with a mandibular advancement device (MAD) and to identify anatomic influences on OSA severity and MAD therapy outcomes.

MATERIALS AND METHODS

Twenty patients with OSA were prospectively treated with MAD. Clinical, cone-beam computed tomography, and polysomnography exams were performed before treatment and 4-6 months after achieving the MAD therapeutic position. Polysomnographic exams and three-dimensional maxillary, mandibular, and upper airway (UA) measurements were evaluated. Pearson's correlation and t-tests were applied.

RESULTS

Before MAD treatment, the transverse width measured at the frontomaxillary suture and the angle between the mandibular ramus and Frankfurt horizontal were statistically correlated with apnea and the hypopnea index (AHI), while the gonial angle was correlated with therapeutic protrusion. After MAD treatment, all patients showed a significant AHI reduction and an improvement in minimum oxyhemoglobin saturation. The UA total volume, superior and inferior oropharynx volume, and area were statistically correlated with MAD therapeutic protrusion. The UA total area showed a statistical correlation with the improvement in AHI, and the superior oropharynx volume and area increased significantly.

CONCLUSIONS

The transversal frontomaxillary suture width and the mandibular ramus facial angle may influence OSA severity. The gonial angle, volume, and area of all UA regions may indicate the amount of protrusion needed for successful MAD treatment.

CLINICAL RELEVANCE

The craniofacial characteristics reported as important factors for OSA severity and MAD treatment outcomes impact therapy planning for OSA patients, considering individual anatomic characteristics, prognosis, and cost benefits.

Sleep apnea and unilateral upper and lower extremity allodynia as a result of a large thoracic disc herniation: a case report

Background

Clinically significant disc herniations in the thoracic spine are rare accounting for approximately 1% of all disc herniations. In patients with significant spinal cord compression, presenting symptoms typically include ambulatory dysfunction, lower extremity weakness, lower extremity sensory changes, as well as bowl, bladder, or sexual dysfunction. Thoracic disc herniations can also present with thoracic radiculopathy including midback pain and radiating pain wrapping around the chest or abdomen. The association between thoracic disc herniation with cord compression and sleep apnea is not well described.

Case presentation

The following is a case of a young male patient with high grade spinal cord compression at T7-8, as a result of a large thoracic disc herniation. The patient presented with complaints of upper and lower extremity unilateral allodynia and sleep apnea. Diagnosis was only made once the patient manifested more common symptoms of thoracic stenosis including left lower extremity weakness and sexual dysfunction. Following decompression and fusion the patient’s allodynia and sleep apnea quickly resolved.

Conclusions

Thoracic disc herniations can present atypically with sleep apnea. We recommend taking into consideration that sleep symptoms may resolve when planning treatment for thoracic disc herniation.

Integration between the cranial boundaries of the nasopharynx and the upper cervical vertebrae in Homo and Pan

The nasopharynx is an important anatomical structure involved in respiration. Its bony boundaries, including the basicranium and upper cervical vertebrae, may be subject to selective pressures and constraints related to respiratory function. Here, we investigate phenotypic integration, or covariation, between the face, the basicranial boundaries of the nasopharynx, and the atlas and axis to understand constraints affecting these structures. We collected three-dimensional coordinate data from a sample of 80 humans and 44 chimpanzees, and used two-block partial least squares to assess RV (a multivariate generalization of Pearson's r² ), r_PLS , the covariance ratio, and effect size for integration among structures. We find that integration is significant among some of these structures, and that integration between the basicranial nasopharynx and vertebrae and between the face and vertebrae is likely independent. We also find divergences in the pattern of integration between humans and chimpanzees suggesting greater constraints among the human face and nasopharynx, which we suggest are linked to divergent developmental trajectories in the two taxa. Evolutionary changes in human basicranial anatomy, coupled with human-like developmental trajectories, may have required that the face grow to compensate any variation in nasopharyngeal structure. However, we were unable to determine whether the nasopharynx or the face is more strongly integrated with the vertebrae, and therefore whether respiration or biomechanical considerations related to positional behavior may be more strongly tied to vertebral evolution. Future work should focus on greater sample sizes, soft tissue structures, and more diverse taxa to further clarify these findings.

Lumbar spine abnormalities in patients with obstructive sleep apnoea

Previous studies suggested cervical spondylosis as a risk factor for development of obstructive sleep apnoea (OSA). We aimed to assess lumbar disc degeneration in patients with OSA and correlate the findings with symptoms and disease severity. Twenty-seven patients with OSA and 29 non-OSA controls underwent sleep studies and lumbar magnetic resonance imaging (MRI), and completed the Epworth Sleepiness Scale and the 24-item Roland-Morris Disability Questionnaire (RMDQ) questionnaires. Plasma klotho was determined with enzyme-linked immunosorbent assay. Patients with OSA had higher number of disc bulges (4.6 ± 3.7 vs. 1.7 ± 2.5, p < 0.01) and anterior spondylophytes (2.7 ± 4.2 vs. 0.8 ± 2.1, p < 0.01), increased disc degeneration (total Pfirrmann score 16.7 ± 4.7 vs. 13.2 ± 4.1, p < 0.01) and vertebral fatty degeneration (7.8 ± 4.7 vs. 3.8 ± 3.7, p < 0.01). There was no difference in the RMDQ score (0/0-3.5/ vs. 0/0-1/, p > 0.05). Markers of OSA severity, including the oxygen desaturation index and percentage of total sleep time spent with saturation < 90% as well as plasma levels of klotho were correlated with the number of disc bulges and anterior spondylophytes (all p < 0.05). OSA is associated with lumbar spondylosis. Our study highlights the importance of lumbar imaging in patients with OSA reporting lower back pain.

A radiologic parameter that could be applied in the development of sleep apnea in rheumatoid arthritis patients undergoing occipitocervical fusion

BACKGROUND

The prevalence of sleep apnea in rheumatoid arthritis (RA) patients with occipitocervical lesions was 79%. Occipitocervical fusion (OCF) could incur sleep apnea or worsen this condition. Recent studies reported that this complication is caused by stenosis of the oropharyngeal airway accompanying a decrease in the occipitoaxial angle (O-C2a). However, there are several limitations to the application of the O-C2a, which decreases its effectiveness. Therefore, we aimed to evaluate the association between a new radiologic parameter, the CVT/NSL angle (CVT: craniocervical inclination in the second and fourth vertebrae; NSL: Nasion-Sella line), and sleep apnea in RA patients accepting OCF.

METHODS

A total of 35 patients who underwent OCF due to upper cervical lesions secondary to RA and had sleep apnea before surgery were analyzed. Those who have a postoperative apnea-hypopnea index (AHI) < 15 and a ΔAHI ≥50% were considered "responders"; patients were otherwise considered "non-responders." They were analyzed whether pre- and postoperative radiologic parameters and their differences in plain lateral radiographs were correlated to the parameter related to sleep apnea.

RESULTS

The included patients have a mean AHI of 21.9 (range, 10 to 52) before surgery. The mean postoperative CVT/NSLa, ΔCVT/NSLa, andΔO-C2a in complete responders were significantly greater compared with non-responders (p < 0.05). Both the changes in the CVT/NSLa and O-C2a were linearly correlated within patients. However, the R² value for the CVT/NSLa was greater compared with the O-C2a (0.403 vs. 0.203).

CONCLUSIONS

The usefulness of the new craniovertebral angle, CVT/NSLa, as an intraoperative indicator during OCF, is more valuable in comparison with the conventional method of measuring the O-C2a. Measuring the craniovertebral angle is extremely important in the planning of surgical treatment for the development of sleep apnea in rheumatoid arthritis patients undergoing occipitocervical fusion.

Obstructive sleep Apnea's association with the cervical spine abnormalities, posture, and pain: a systematic review

OBJECTIVES

While obstructive sleep apnea (OSA) is associated with several chronic health conditions such as hypertension, obesity, and chronic hypoxia, there is limited information on its association with neuromuscular and spinal pathologies that may be of interest to a musculoskeletal (MSK) medicine or pain management clinician. The objective of this study was to perform a systematic literature review to examine the association between OSA and cervical spine pathologies, postural changes, and pain.

DESIGN

We systematically reviewed PubMed and Embase databases up to 4/15/2019. We included studies that explored associations between OSA and a) pain, b) postural characteristics or changes, or c) cervical spine morphology. Systematic reviews, meta-analysis, randomized control trials, cohort studies, and case-control studies were included. Case reports, narrative reviews or expert opinion papers were excluded. From the articles that met selection criteria, information regarding type, direction and magnitude of such associations was extracted. The OSA-pain association studies were further divided into 3 subgroups: neuropathic, temporomandibular, and chronic pain.

RESULTS

21 articles that met our study criteria were selected for this review. Two studies were on cervical spine pathologies, eight on postural changes, and eleven on pain associated with OSA. Exploring the association between OSA and cervical spine pathologies, postural changes, and pain in this systematic review we found: (1) Cervical spine lesions, fusions, and abnormalities that reduce retropharyngeal space are associated with OSA, likely by way of worsening posture and decreasing range of motion. (2) Head extension and anteriorization are associated with OSA likely as a compensatory mechanism. Extension may improve airway function, while anteriorization helps to maintain visual sense. (3) Head-of-bed-elevation may improve OSA symptoms and can possibly supplement other conservative treatment measures. (4) Neuropathic pain is associated with OSA, likely by way of inflammatory pathways. (5) Oral appliance use (eg mandibular advancement/protruding device) in OSA likely contributes to transient temporomandibular pain. (6) There is little association between OSA and chronic pain prevalence. (7) Increased pain intensity and decreased pain tolerance are somewhat associated with OSA, likely by way of hypoxemia and sleep fragmentation.

CONCLUSIONS

Clinicians in MSK and pain medicine need to consider these associations and consider obtaining imaging studies and/or making referrals for management of their OSA to better provide appropriate care to these patients.

New Diagnosis of Obstructive Sleep Apnea Following Anterior Cervical Discectomy Complicated by Rheumatoid Arthritis: A Case Report

Obstructive sleep apnea (OSA) is the most common variant of sleep-disordered breathing that often goes undiagnosed. OSA is characterized mainly by anatomical obstruction or partial collapse of upper airways during sleep. The obstruction is multifactorial, and a lesser-known fact is that damage to the pharyngeal plexus during head and neck procedures or placement of hardware in the cervical area can lead to narrowing or collapse of the upper airway. We present such a case of a 59-year-old female who developed new-onset OSA after undergoing anterior cervical discectomy and fusion (ACDF). The severity of OSA worsened with the progression of her rheumatoid arthritis (RA) in the cervical region. This case report aims to raise awareness of such an association among clinicians to enable them to screen appropriate patients for sleep-disordered breathing and treat them accordingly.

Cervical Spine Hyperextension and Altered Posturo-Respiratory Coupling in Patients With Obstructive Sleep Apnea Syndrome

Obstructive sleep apnea syndrome (OSAS) is associated with postural dysfunction characterized by abnormal spinal curvature and disturbance of balance and walking, whose pathophysiology is poorly understood. We hypothesized that it may be the result of a pathological interaction between postural and ventilatory functions. Twelve patients with OSAS (4 women, age 53 years [51–63] (median [quartiles]), apnea hypopnea index 31/h [24–41]) were compared with 12 healthy matched controls. Low dose biplanar X-rays (EOS® system) were acquired and personalized three-dimensional models of the spine and pelvis were reconstructed. We also estimated posturo-respiratory coupling by measurement of respiratory emergence, obtaining synchronized center of pressure data from a stabilometric platform and ventilation data recorded by an optico-electronic system of movement analysis. Compared with controls, OSAS patients, had cervical hyperextension with anterior projection of the head (angle OD-C7 12° [8; 14] vs. 5° [4; 8]; p = 0.002), and thoracic hyperkyphosis (angle T1–T12 65° [51; 71] vs. 49° [42; 59]; p = 0.039). Along the mediolateral axis: (1) center of pressure displacement was greater in OSAS patients, whose balance was poorer (19.2 mm [14.2; 31.5] vs. 8.5 [1.4; 17.8]; p = 0.008); (2) respiratory emergence was greater in OSAS patients, who showed increased postural disturbance of respiratory origin (19.2% [9.9; 24.0] vs. 8.1% [6.4; 10.4]; p = 0.028). These results are evidence for the centrally-mediated and primarily respiratory origin of the postural dysfunction in OSAS. It is characterized by an hyperextension of the cervical spine with a compensatory hyperkyphosis, and an alteration in posturo-respiratory coupling, apparently secondary to upper airway instability.

Ankylosing Spondylitis Is Associated With Risk of New-Onset Obstructive Sleep Apnea: A Nationwide Population-Based Cohort Study

Objectives: Investigating the risk of obstructive sleep apnea(OSA) among ankylosing spondylitis (AS) patients based on administrative healthcare databases.

Methods: We conducted a nationwide cohort study by using the Taiwan National Health Insurance Research Database with 1997–2013 claim records. The AS cohort included 2,210 patients who were newly diagnosed between 2003 and 2013. Randomly selected non-AS controls were matched at a 1:4 ratio. The endpoint was set as OSA occurrence or the end of 2013. Cumulative incidences, hazard ratios (HRs) and 95% confidence intervals (CIs) were calculated after adjusting for age, gender, comorbidities, and co-medication. Multivariate analyses were performed using the Cox proportional hazards model. Due to the violation of the proportionality assumption, landmark analysis was conducted to explore the risk of OSA during specific follow-up periods.

Results: The adjusted HR (aHR) of OSA in the AS group was 2.826 (95% C.I. = 1.727–4.625) compared to the control group. On landmark analysis, aHR was 7.919 (95% C.I. = 3.169–19.792) for the AS group 0–24 months from the index date and decreased to 1.816 (95% C.I. = 0.944–3.494) at ≥ 24 months from the index date. The increased risks of OSA in the AS group compared to the control group were found for both males and females (aHRs were 4.533 and 2.672). On age-stratified analysis, a significant risk only for the 40–59 age group with aHR of 3.913 (95% C.I. = 1.890–8.102).

Conclusions: A higher risk of developing OSA was found among newly diagnosed AS cohort during the maximum 11-year follow-up period, especially within 2 years after newly diagnosed AS and in the 40–59 age group.

Unstable os odontoideum contributing to cervical myelopathy and obstructive sleep apnea

Background:

Sleep apnea is characterized by repetitive cessation of breathing during sleep. It may be attributed to obstructive, central, or mixed pathologies close to the upper airway resulting in a decreased diameter of the oropharyngeal tract.

Case Description:

A 36-year-old male with progressive cervicomedullary myelopathy/quadriparesis exhibited obstructive sleep apnea (OSA) attributed to an anteriorly displaced os odontoideum (OO). Atlantoaxial screw-rod stabilization resulted in improvement of both neurological function and OSA.

Conclusion:

A symptomatic unstable OO may contribute to suboccipital pain, progressive quadriparesis, vertebrobasilar insufficiency, and OSA. Appropriate operative intervention utilizing atlantoaxial screw-rod stabilization may help to resolve these deficits.

The possible impact of cervical stenosis on cephalad neuronal dysfunction

Earlier observers have speculated on the causal relationships between abnormal CSF circulation and a variety of neurological dysfunctions. Such speculations have been at least partially validated by recent evidence and inquiries contravening the traditional static viewpoint of CSF circulation. More contemporary inquiries establish a number of factors which influence both CSF production and absorption (sleep disturbance, neck position, cerebral metabolism, brain atrophy, medications, etc.). Thus, transient periods of abnormality are possibly mingled with periods of normality. Such episodic alterations suggest that the physiological arrangements which underpin CSF circulation may be in some ways likened to blood pressure alterations, in that long-standing CSF abnormalities may be both unappreciated and gradual, though virulent enough to cause substantial neurological injury. We suggest that cervical stenosis (blocking an important CSF decompressive pathway into the vertebral canal) is among the largely unappreciated causes of abnormal CSF circulation and may play a role in cephalad neuronal dysfunction. Such a blockage is correlated with age and easily assessed by cine MRI study. Indeed, episodic disturbances can diminish CSF cerebral flow circulation increasing deposition in cerebral parenchyma of contrary metabolic products (e.g. beta Amyloid), possibly having a causal influence on senile dementia. Additionally, cervical stenosis, by increasing posterior fossa cerebral pressure, could play a causal role in a number of afflictions, among them sleep apnea, concomitant respiratory and circulatory dysfunction, hypertension, chronic occipital headaches, tinnitus, etc. We further suggest that among those patients with substantial cervical stenosis (extensive enough to block CSF circulation in the cervical area as identified by cine MRI) appropriate comparative clinical studies could be undertaken to demarcate associations with presenile dementia, sleep disturbance and posterior fossa dysfunction. Additionally, we suggest that an intracranial monitoring implant be perfected to chronically monitor both intracranial pressure and CSF flow - a monitoring device comparable to the rather less invasive sphygmometric evaluation of blood pressure. If such speculations prove correct, different therapeutic regimens which might improve outcome could be imagined. Among them better sleep hygiene (to by position maximize CSF flow) and possibly more aggressive operative decompressive intervention to diminish cervical obstruction.

Dyspnea in the Supine Position after Anterior Cervical Discectomy and Fusion

Posterior occipitocervicothoracic fusion in a flexed position may cause dyspnea, and the onset of obstructive sleep apnea after anterior upper cervical fusion. However, there are no reports of dyspnea occurring after anterior lower cervical fusion. Here, we present an unusual case of dyspnea in the supine position after a C5-C6 anterior cervical discectomy and fusion.

Pre-optimization of spinal surgery patients: Development of a neurosurgical enhanced recovery after surgery (ERAS) protocol

OBJECTIVE

Despite surgical, technological, medical, and anesthetic improvements, patient outcomes following elective neurosurgical procedures can be associated with high morbidity. Enhanced recovery after surgery (ERAS) protocols are multimodal care pathways designed to optimize patient outcomes by addressing pre-, peri-, and post-operative factors. Despite significant data suggesting improved patient outcomes with the adoption of these pathways, development and implementation has been limited in the neurosurgical population.

METHODS/RESULTS

This study protocol was designed to establish the feasibility of a randomized controlled trial to assess the efficacy of implementation of an ERAS protocol on the improvement of clinical and patient reported outcomes and patient satisfaction scores in an elective inpatient spine surgery population. Neurosurgical patients undergoing spinal surgery will be recruited and randomly allocated to one of two treatment arms: ERAS protocol (experimental group) or hospital standard (control group). The experimental group will undergo interventions at the pre-, peri-, and post-operative time points, which are exclusive to this group as compared to the hospital standard group.

CONCLUSIONS

The present proposal aims to provide supporting data for the application of these specific ERAS components in the spine surgery population and provide rationale/justification of this type of care pathway. This study will help inform the design of a future multi-institutional, randomized controlled trial.

RESULTS

of this study will guide further efforts to limit post-operative morbidity in patients undergoing elective spinal surgery and to highlight the impact of ERAS care pathways in improving patient reported outcomes and satisfaction.

Pharyngeal Airway Dimensions and Head Posture in Obstructive Sleep Apnea Patients with and without Morphological Deviations in the Upper Cervical Spine

Objectives

The aim of the study was to analyse differences in pharyngeal airway dimensions and head posture between obstructive sleep apnea patients with and without morphological deviations in the upper cervical spine and to analyse associations between pharyngeal airway dimensions and head posture in the total sample.

Material and Methods

The sample comprised 53 obstructive sleep apnea (OSA) patients of which 32.1% had upper spine morphological deviations. Accordingly two groups were defined: 17 OSA patients with morphological deviations in the upper spine and 36 without upper spine deviations. Pharyngeal airway dimensions in terms of distances, cross-sectional areas and volume and upper spine morphological deviations were evaluated on cone-beam computed tomography. Head posture was evaluated on two-dimensional generated lateral cephalograms. Differences were analysed and adjusted for age and gender by multiple linear regression analysis.

Results

OSA patients with upper spine morphological deviations had a significantly more backward and curved neck posture (OPT/HOR, P < 0.01; OPT/CVT, P < 0.05) compared to OSA patients without spine deviations. No significant differences were found in airway dimensions between patients with and without upper spine deviations. In the total group significant associations were found between head posture and pharyngeal airway distances and cross-sectional area at the nasal floor, epiglottis and hyoid bone level (P < 0.05, P < 0.01, P < 0.001). No significant association was found between head posture and airway volume.

Conclusions

The results may contribute to differentiate obstructive sleep apnea patients and thereby may prove valuable in diagnosis and treatment planning of obstructive sleep apnea patients.

Risk of obstructive sleep apnoea in patients with rheumatoid arthritis: a nationwide population-based retrospective cohort study

OBJECTIVE

Sleep disorders are prevalent medical disorders in patients with rheumatoid arthritis (RA). However, whether patients with RA are at an increased risk of developing obstructive sleep apnoea (OSA) is unclear.

DESIGN

Using population-based retrospective cohort study to examine the risk of OSA in patients with RA.

SETTING

We used claims data of the National Health Insurance Research Database (NHIRD) of Taiwan.

PARTICIPANTS

We identified a RA cohort with 33 418 patients newly diagnosed in 2000-2010 and a randomly selected non-RA comparison cohort with 33 418 individuals frequency matched by sex, age and diagnosis year.

PRIMARY AND SECONDARY OUTCOME MEASURES

Incident OSA was estimated by the end of 2011. The HRs of OSA were calculated using the Cox proportional hazards regression analysis.

RESULTS

The overall incidence rate of OSA was 75% greater in the RA cohort than in the non-RA cohort (3.04 vs 1.73/10 000 person-years, p<0.001), with an adjusted HR (aHR) of 1.75 (95% CI 1.18 to 2.60). Stratified analyses by sex, age group and comorbidity revealed that the incidence rates of OSA associated with RA were higher in all subgroups.

CONCLUSIONS

This population-based retrospective cohort study suggested that patients with RA should be monitored for the risk of developing OSA.