Prevertebral soft tissue swelling following trauma: usefulness following tube placement

Airway management in patients with deep neck infections: A retrospective analysis

Securing the airway in patients undergoing surgical intervention to control a deep neck infection (DNI) is challenging for anesthesiologists due to the distorted airway anatomy, limited mouth opening, tissue edema, and immobility. It is critical to assess the risk of a potential difficult airway and prepare the most appropriate airway management method.We reviewed our anesthetic experiences managing patients with DNIs, focusing on the need for video-laryngoscope or awake fiberoptic intubation beyond a standard intubation from the anesthesiologist's perspective.When patients had infections in the masticatory space, mouth of floor, oropharyngeal mucosal space, or laryngopharynx, their airways tended to be managed using methods requiring more effort by the anesthesiologists, and more extensive equipment preparation, compared with use of a standard laryngoscope. The degree to which the main lesion influenced the airway anatomy, especially at the level of epiglottis and aryepiglottic fold was related to the airway management method selected.When managing the airways of patients undergoing surgery for DNIs under general anesthesia, anesthesiologists should use imaging with computed tomography to evaluate the preoperative airway status and a comprehensive understanding of radiological findings, comorbidities, and patients' symptoms is needed.

Upright magnetic resonance imaging measurement of prevertebral soft tissue in the cervical spine of normal volunteers

BACKGROUND CONTEXT

Anteroposterior width of prevertebral soft tissues (PVSTs) in the cervical spine has long been considered a valuable radiographic measurement for evaluation of occult cervical spine pathology. These measurements, generally obtained from lateral radiographs of the cervical spine, have been used clinically as references for the evaluation of patients with traumatic, neoplastic, or other cervical spine disorders. Magnetic resonance imaging (MRI) offers a subtle delineation of the soft-tissue structures anterior to the vertebral column, with the potential for more accurate and sensitive determination of PVST width. Upright magnetic resonance images permit comparison with and validation of previously reported upright lateral radiographic measurements of PVST width. To our knowledge, evaluation of cervical spine PVST width using upright MRI has not been previously published in the English literature.

PURPOSE

The purposes of this study were to validate lateral radiographic measurements of PVST width using upright weight-bearing MRI in healthy subjects and quantify effects of spinal level and gender.

STUDY DESIGN

Clinical study in asymptomatic volunteers.

METHODS

Eleven male and eight female volunteers consented and were enrolled in the study. All volunteers were asymptomatic and had no history of cervical spine injury or degenerative disease. Prevertebral soft-tissue width was measured at each cervical level from C2 to C7 using upright weight-bearing MRI. Statistically significant differences in PVST width based on spinal level and gender were determined using two-factor analysis of variance.

RESULTS

Width magnitudes were significantly dependent on gender (p<.0001) and spinal level (p<.0001). All C3 and C6 measurements were below the traditionally accepted values of 7 and 20 mm, respectively, that would be considered "abnormal." Prevertebral soft-tissue width was greater in men at upper and lower extents of the cervical spine. Prevertebral soft-tissue widths reported in the present study were similar in magnitude and level-by-level trends to measurements of asymptomatic volunteers obtained using lateral radiography.

CONCLUSION

The present study validated the use of lateral radiography to measure PVST width, presented level-by-level and gender-specific normative data, and provided a weighted statistical analysis of differences between normal volunteers and injured patients.

Cervical Prevertebral Soft Tissue Swelling in the Traumatized Patient: What is Normality in the Intubated Patient?

Interpretation of prevertebral soft tissue swelling is generally thought to be invalid in the presence of an endotracheal tube (ETT). There is however little scientific data to support this.We evaluate the prevertebral soft tissue swelling of 43 traumatized patients that have had an endotracheal tube (ETT) placed in the acute setting. A control group of 92 patients were also evaluated which had been subjected to acute trauma and no ETT. There was a significant increase in soft tissue swelling (p < 0.0001) found in the ETT group at the C2 level compared to the non-tube group. There was no significant difference between the two groups at the C4 and C6 levels.We feel that interpretation of prevertebral swelling in the traumatized patient at the C2 level is invalid in the presence of an ETT, and indeed is significantly increased after intubation despite no injury at this level. However, the interpretation of soft tissue swelling at and below C4 remains a useful tool in the evaluation of an occult cervical injury.

Normal thickness and appearance of the prevertebral soft tissues on multidetector CT

BACKGROUND AND PURPOSE

Analysis of the prevertebral soft tissue (PVST) is helpful in detecting osseous and ligamentous injuries of the cervical spine. Because the standard of care has shifted from radiographs to multidetector CT (MDCT), a re-examination of the PVST on MDCT images is needed to establish normal values for thickness appropriate for this imaging technique.

MATERIALS AND METHODS

Thickness of the PVST was measured in 192 patients undergoing screening cervical spine MDCT with multiplanar reconstructions as part of a trauma protocol. Patients included in the study were not intubated, had an immobilized cervical spine, had normal findings on cervical spine CT, and did not have a diagnosis of osseous or soft-tissue cervical injury. Exclusion criteria included patients with a congenital or acquired (nondegenerative) abnormality of the cervical spine or PVST.

RESULTS

The upper limits of normal for the thickness of the PVST were 8.5 mm at C1, 6 mm at C2, 7 mm at C3, 18 mm at C6, and 18 mm at C7. The upper limit of normal was not determined for C4 and C5 levels due to variable position of the esophagus and larynx. The smallest variability and calculated SDs were found at C2 and C3.

CONCLUSIONS

The thickness of the PVST is important in the detection of underlying injuries to the cervical spine. We propose the obtained values as the upper limits of normal for PVST thickness on MDCT images in the adult population.

"Normal" prevertebral soft tissue swelling following elective anterior cervical decompression and fusion

INTRODUCTION

Prevertebral soft tissue swelling (PSTS) has been evaluated in the setting of traumatic cervical spine injuries. However, no study to date has quantified the PSTS following elective anterior cervical decompression and fusion or the time course to resolution of that swelling.

METHODS

From May 2002 to May 2005 the senior author performed 193 elective 1- or 2-level anterior cervical decompression and fusions. Patients who underwent corpectomies and anterior cervical fusions for trauma or tumor were excluded. Preoperative, 2-week postoperative and 6-week postoperative radiographs were available on 100 patients. The prevertebral soft tissue stripe was measured on the neutral lateral radiographs for the 3 time points. The mean swelling (mm) for each time point was calculated and stratified by cervical level. Repeated measures analysis of variance with the Tukey-Kramer multiple comparisons test was used to compare the measured swelling at the various time points.

RESULTS

The average PSTS was calculated for each cervical level, for each of the 3 time points, preoperative, 2- and 6-week postoperative. There was a significant increase in PSTS between the preoperative and 2-week postoperative measurements at all levels. There is a significant decrease in PSTS between 2- and 6-week postoperatively at all cervical levels. There is no significant change in PSTS at C2, C3, and C5, when comparing the preoperative and 6-week postoperative measurements. There is significant PSTS at C4, C6, and C7, when comparing preoperative and 6-week postoperative measurements.

CONCLUSIONS

The "normal" range for PSTS at 2 weeks and at 6 weeks after elective 1- and 2- level anterior cervical decompression and fusions is described. Our data demonstrates that edema persists at the 2-week follow-up. By 6 weeks postoperative, the increased PSTS has greatly dissipated.

Significance of prevertebral soft tissue measurement in cervical spine injuries

OBJECTIVE

The objective of this study was to evaluate the diagnostic value of prevertebral soft tissue swelling in cervical spine injuries.

MATERIALS AND METHODS

A group of 107 consecutive patients with suspected injuries of the cervical vertebrae were reviewed retrospectively to identify the presence of prevertebral soft tissue swelling and to investigate the association of prevertebral soft tissue swelling with the types and degrees of cervical spine injuries.

RESULTS

Prevertebral soft tissue swelling occurred in 47 (43.9%) patients. Of the 47 patients, 38 were found with bony injury and nine were without. The statistic difference was significant (P < 0.05). No correlation was demonstrated between soft tissue swelling and either the injured level of the cervical vertebrae or the degree of the spinal cord injury (P > 0.05). Anterior element injuries in the cervical vertebrae had widening of the prevertebral soft tissue more than posterior element injuries (P < 0.05).

CONCLUSION

The diagnostic value of prevertebral soft tissue swelling for cervical spine injuries is significant, but the absence of this sign does not mean that further image evaluation can be spared.