Prolonged airway obstruction after posterior occipitocervical fusion: a case report and literature review

The most appropriate cervical vertebra for the measurement of occipitocervical inclination parameter: a validation study of C3, C4, and C5 levels using multi-positional magnetic resonance imaging

PURPOSE

To evaluate which cervical level is the most appropriate level to measure occipitocervical inclination (OCI).

METHODS

Sixty-two patients with multi-positional MRI: 24 males and 38 females, who had cervical lordosis and had a disk degeneration grade of 3 or less were included. We measured patient's OCI at C3, C4, and C5, occipitocervical angle (OCA), occipitocervical distance (OCD), C2-7 angle, and cervical sagittal vertical axis (cSVA) in neutral, flexion, and extension position. The correlation between OCI and OCA, OCD, C2-7 angle, and cSVA on each cervical level in all three positions was tested using Pearson's correlation coefficient test. The difference between OCIs at each cervical level was tested by Wilcoxon signed-rank test. p value of less than 0.05 was set as a statistically significant level.

RESULTS

C5 OCI showed statistically significant correlation with OCA, OCD, C2-7 angle, and cSVA in all three positions (p < 0.05, r = 0.214-0.525). C3 OCI in flexion (p = 0.393, r = 0.081) and C4 OCI in neutral and flexion (neutral p = 0.275, r 0.104; flexion p = 0.987, r = 0.002) did not show significant correlation with C2-7 angle. There was a statistically significant difference between C3, C4, and C5 OCIs in neutral and extension position (p < 0.05). At the same time, OCI showed statistically strong correlation between adjacent cervical levels (p < 0.001, r = 0.627-0.822).

CONCLUSION

C5 cervical level is the most appropriate level for OCI measurement. OCI should be measured at the same cervical level at all time. C4 OCI can reliably substitute C5 OCI in case C5 which is invisible on radiographic image. These slides can be retrieved under Electronic Supplementary Material.

Retrospective audit of airway management practices in children with craniocervical pathology

BACKGROUND

Craniocervical immobilization using halo body orthoses may be required in the management of children with craniocervical junction pathology. To date, the effect of such immobilization on perioperative anesthetic management has not been addressed in large series.

AIMS

The aim of this study was to review the airway management of children requiring halo body orthoses undergoing general anesthesia.

METHODS

The study was a retrospective case note review from a single institution. The neurosurgical database was interrogated to identify all patients less than 16 years of age that required a halo body orthosis from 1996 to 2015. We used the electronic patient record to identify all procedures performed under general anesthesia for these patients, either for halo application, or with the halo in situ. Details of techniques used for airway management were recorded, and paired data between individuals pre- and post-halo application were compared. Demographic data, diagnosis, and perioperative complications were also recorded.

RESULTS

We identified 90 children that underwent placement of a halo body orthosis. A total of 269 anesthetic records from these patients were analyzed and classified as pre-halo application, or halo in situ. Facemask ventilation was achieved in all patients, though some required simple airway adjuncts and may have been more difficult in the presence of the halo. Supraglottic airways were used successfully in many patients. There was a significant increase in the number of patients classed as Cormack and Lehane grades 3 or 4 on direct laryngoscopy with the halo in situ compared with before the halo was applied. The incidence of intubation using fiberoptic or videolaryngoscopy was higher with the halo in situ. Multiple intubation attempts were required in 3.4% (1/29) of patients undergoing anesthesia for halo placement compared with 15.1% (11/73) undergoing anesthesia with a halo in situ.

CONCLUSION

Airway management in children with cervical spine pathology should be anticipated to be more difficult than the general pediatric population. This is likely to be due to co-existing pathology associated with cervical spine disease in children, limitation of neck movement to prevent further neurological injury, and the halo itself limiting access to the head. We recommend advanced preparation, and ensuring the immediate availability of an anesthetist with skills in managing the pediatric difficult airway to avoid complications in this patient population.

A New Method of Measuring the Occipitocervical Angle That Could be Applied as an Intraoperative Indicator During Occipitocervical Fusion

STUDY DESIGN

A method for measuring occipitocervical angle.

OBJECTIVE

To develop a new method of measurement for assessing the occipitocervical angle using intraoperative fluoroscopic imaging, and to examine its reliability.

SUMMARY OF BACKGROUND DATA

To avoid postoperative complications following occipitocervical fusion, it is vital to obtain a suitable fusion angle between the occipital bone and the upper cervical spine.

MATERIALS AND METHODS

The subjects were 30 cases with occipito-atlanto-axial lesions and 30 healthy volunteers. Lateral plain radiographs of the cervical spine in neutral position were used to draw the McGregor line, the line between the external occipital protuberance and the most caudal point on the midline occipital curve (Oc line), the tangential line of the inferior endplate of the C2 vertebra (C2 line), and the posterior longitudinal line of the C2 vertebra (Ax line). The angles formed by these 4 lines and the horizontal line were measured. The O-C2 angle and the Oc-Ax angle, the new indicator, were measured by 3 doctors and reliability was evaluated.

RESULTS

In the disease group, mean intraobserver variances of the McGregor, Oc, C2, Ax, O-C2, and Oc-Ax angles were 0.7, 1.3, 1.5, 1.2, 1.6, and 1.9 degrees. Mean intraobserver intraclass correlation coefficients were 0.997, 0.994, 0.994, 0.997, 0.989, and 0.988, showing high intraobserver reliability for all angles. Mean interobserver intraclass correlation coefficients were 0.998, 0.996, 0.994, 0.997, 0.988, and 0.990, showing high interobserver reliability for all angles. The same reliability was obtained in the healthy group.

CONCLUSIONS

The Oc-Ax angle is as reliable an indicator as the conventional O-C2 angle, and could be used as a new intraoperative indicator for occipitocervical fusion. It may be particularly useful in cases where it is difficult to identify the McGregor line and/or the inferior endplate of the C2 vertebra.

LEVEL OF EVIDENCE

Level 3-diagnostic study.

Airway adverse events following posterior occipito-cervical spinal fusion

Management of the airway may be challenging in patients undergoing occipito-cervical spine fusions (OCF). Changes in the occipito-cervical angle (dOC2A) of fusion after surgery may result in acute airway obstruction, dyspnea and/or dysphagia. Objectives of the study were to review the airway management of patients during posterior OCF, determine the incidence, nature and risk factors for postoperative airway adverse events (AEs), and to determine the relationship between airway AEs and the change in dOC2A. In this retrospective cohort of 59 patients, following extubation in the operating room (OR), there were no complications in 43 (73%) patients (Group 1). Sixteen (27%) patients (Group 2) had airway complications; 4 requiring reintubation and 12 having delayed extubation. The number of vertebral levels fused (>6), presence of difficult intubation and duration of surgery (>5h) were significantly associated with AEs. There was no significant difference in the dOC2A between the groups (-1.070±5.527 versus -4.375±10.788, p=0.127). Airway management in patients undergoing OCF poses a challenge for the anesthesiology and surgical teams. The incidence of AEs was 27%. The decision to extubate immediately after surgery needs to be individualized. Factors such as difficult intubation, number of vertebral levels fused and duration of surgery have to be considered. A significant correlation between dOC2A and postoperative AEs could not be established. Risk factors for postoperative AEs are multifactorial and prospective evaluation of these factors is indicated.

Tracheal extubation of the adult intensive care patient with a predicted difficult airway - a narrative review

Management of the difficult airway is an important, but as yet poorly-studied, component of intensive care management. Although there has been a strong emphasis on prediction and intubation of the difficult airway, safe extubation of the patient with a potentially difficult airway has not received the same attention. Extubation is a particularly vulnerable time for the critically ill patient and, because of the risks involved and the consequences of failure, it warrants specific consideration. The Royal College of Anaesthetists 4th National Audit Project highlighted differences in the incidence and consequences of major complications during airway management between the operating room and the critical care environment. The findings in the section on Intensive Care and Emergency Medicine reinforce the importance of good airway management in the critical care environment and, in particular, the need for appropriate guidelines to improve patient safety. This narrative review focuses on strategies for safe extubation of the trachea for patients with potentially difficult upper airway problems in the intensive care unit.