Early Reduction in C-Reactive Protein Following Treatment for Spinal Epidural Abscess: A Potential Treatment Guide

Impact of Vascularity on Spinal Disorders Outcomes, Underestimated yet Probably Crucial: The Example of a Comparative Cohort of Epidural Abscesses

STUDY DESIGN

Retrospective comparative cohort.

OBJECTIVE

(1) Describe the prevalence of the basivertebral vessel (BVV) in a cohort of spinal epidural abscesses (SEA) at lumbar or thoracic (2) correlate the presence of BVV to the risk of conservative treatment failure (CTF).

METHODS

Twenty-six patients successfully managed without surgery were compared to 26 who required surgical management due to failed conservative management (lumbar and thoracic). Two observers sought the BVV on the sagittal T1 with contrast sequences of the initial MRI in a blinded fashion for Kappa score calculation. BVV-/BVV+: absence/presence. Demographic, radiological, and laboratory parameters, as well as functional scores, were recorded.

RESULTS

For both observers, 29/52 patients had a BVV+ (55.7%); the agreement was 84% (Kappa: 0.80 CI 95% [0.70-0.90]). 5/23 (21.7%) BVV- patients had a successful medical treatment, while the proportion was 21/29 (72%) for BVV+ (P = .0003). The positive predictive value for BVV+, predicting successful conservative treatment, was 81%. The negative predictive value for BVV- predicting CTF was 69%. BVV- was predictive of CTF in multivariable logistic regression: OR = 40, CI 95% [5-880], P = .02, for agreed observations between observers. For both observers, the proportion of dorsal abscess was the highest for BVV+ (P = .01).

CONCLUSION

The BVV is part of the epidural network. The absence of BVV was strongly correlated with an increased risk of CTF, leading to the need for subsequent surgical treatment. SEA's location pattern varied according to BVV detection. Although the spinal vascular anatomy has been well-known for over 100 years, there are still very few studies on its pathophysiological implications.

Spinal epidural abscess: Does social deprivation influence 1-year mortality?

BACKGROUND

Spinal epidural abscess are difficult to diagnose due to its non-specific clinical presentation. Spinal epidural abscess is identified late or missed in almost half of patients. To better assist clinicians in making this diagnosis there needs to be a better appreciation of at risk patient profile.

METHODS

We identified all patients who were admitted to a tertiary referral centre with a diagnosis of spinal epidural abscess between February 2009 and January 2022. Demographic details, presentation details, past medical history, concurrent infection, and social factors were recorded for all patients. The primary aim of our study was to examine if there is a relationship between social deprivation and risk of mortality at one year in patients with spinal epidural abscess.

RESULTS

There were 140 eligible patients associated with 146 hospital encounters for spinal epidural abscess. Eighteen patients died at ≤365 days post discharge, while 122 patients were alive at >365 days post discharge. There were 86 males and 54 females. The average age was 59.9 years with an IQR of 19.3. There were 28 % Māori, 58 % European and 12 % of all other ethnicities. In the most deprived quantile there were 34.5 %, compared to 7.5 % in the least deprived quantile. Multivariate stepwise regression analysis found that age, mean neutrophil count and congestive heart failure all showed a statistically significance association with mortality at one year. There was no association between one year mortality and these variables: deprivation status, rurality or Māori ethnicity.

CONCLUSION

Mortality at one year appears to be significantly associated with age, mean neutrophil count and congestive heart failure. There was no obvious association between deprivation and mortality at one year. Identifying patients at the greatest risk of mortality remains a complex challenge.

External Validation of the Spinal Orthopedic Research Group Index for Spinal Epidural Abscess 90-Day Mortality in a Geographically Remote Population

STUDY DESIGN

Retrospective cohort study.

OBJECTIVE

To externally validate the Spinal Orthopaedic Research Group (SORG) index for predicting 90-day mortality from spinal epidural abscess and compare its utility to the 11-item modified frailty index (mFI-11) and Charlson comorbidity index (CCI).

SUMMARY OF BACKGROUND DATA

Providing a mortality estimate may guide informed patient and clinician decision-making. A number of prognostic tools and calculators are available to help predict the risk of mortality from spinal epidural abscess, including the SORG index, which estimates 90-day postdischarge mortality. External validation is essential before wider use of any clinical prediction tool.

MATERIALS AND METHODS

Patients were identified using hospital coding. Medical and radiologic records were used to confirm the diagnosis. Mortality data and data to calculate the SORG index, mFI-11, and CCI were collected. Area under the curve and calibration plots were used to analyze.

RESULTS

One hundred and fifty patients were included: 58 were female (39%), with a median age of 63 years. Fifteen deaths (10%) at 90 days postdischarge and 20 (13%) at one year. The mean SORG index was 13.6%, the mean CCI 2.75, and the mean mFI-11 was 1.34. The SORG index ( P =0.0006) and mFI-11 ( P <0.0001) were associated with 90-day mortality. Area under the curve for SORG, mFI-11, and CCI were 0.81, 0.84, and 0.49, respectively. The calibration slope for the SORG index showed slight overestimation in the middle ranges of the predicted probability, more so than mFI-11, and was not well-calibrated over the higher ranges of predicted probability.

CONCLUSIONS

This study externally validated the SORG index, demonstrating its utility in our population at predicting 90-day mortality; however, it was less well calibrated than the mFI-11. Variations in algorithm performance may be a result of differences in socioethnic composition and health resources between development and validation centres. Continued multicenter data input may help improve such algorithms and their generalisability.

Keeping It Simple: Developing a Prognostic Tool for Spinal Epidural Abscess

STUDY DESIGN

A retrospective study.

OBJECTIVE

To develop a prognostic score for mortality and treatment failure in Spinal epidural abscess (SEA), based on simplicity and multidimensional assessment principles.

METHODS

One-hundred-fifty patients were reviewed. Variables assessed included comorbidities, functional status, clinical presentation, Frankel classification, and biochemical and radiological parameters. The main outcomes were the 90-day mortality and treatment failure, corresponding to any intensification of the initial treatment plan. Variables were sorted out with a factorial analysis. Logistic regressions were performed, and the new score was derived from the coefficients. ROC curves with Area Under Curve, calibration plots, and cross-validation were performed.

RESULTS

Forty-three patients (29%) had treatment failure, and 15 died (10%) by 90 days. Factorization created 3 groups: Comorbidities (C), Severity (S), and Function (F). For 90-day mortality, Odds ratios were 1.20 (P = .0002), 1.15, (P = .03), 1.36, (P < 10-4) for C, S, F, respectively. The new score 'CSF' had 1 point per item, ranging from zero to 3. OR increased by 1.2/point for 90-day mortality (P < 10-4), AUC was .86. For failures OR increased by 1.15/point (P = .014), AUC was .58, and increased to .64 for patients who survived after 90 days, probably due to competing risks.

CONCLUSIONS

Comorbidities, Severity, and Function is a new simplistic tool, easy to use in daily practice; its performances were excellent for 90-day mortality, and acceptable for failures. Simple tools are more likely to be adopted into practice. External validation of this technique is desirable.