Lymphopenia at 4 Days Postoperatively Is the Most Significant Laboratory Marker for Early Detection of Surgical Site Infection Following Posterior Lumbar Instrumentation Surgery

A novel approach for identifying serological markers indicative of surgical-site infection following spine surgery: Postoperative lymphopenia is a risk factor

BACKGROUND

Postoperative lymphopenia (PL) after spine surgery is reported to be an indicator of surgical-site infection (SSI). PL without SSI is often encountered, resulting in a treatment dilemma. We focused on PL, so as to improve the accuracy of detecting SSI.

METHODS

In total, 329 patients underwent spine surgery, including nine patients presenting with SSI. The complete blood cell counts, differential counts, and C-reactive protein (CRP) level were measured pre-surgery and on postoperative days 2, 7, and 14. The relationships between PL and SSI were evaluated, and PL and non-PL conditions were compared among all cases. We then divided the patients into two groups: PL and non-PL, and determined the useful serological markers using receiver operating characteristic curves.

RESULTS

Sixty-one patients presented with PL, including four with SSI. However, PL was not directly suggested as a biomarker of SSI (p = 0.067). We revealed PL as a risk factor for SSI (p = 0.004, Odds ratio: 7.54). Among all cases, the lymphocyte count and CRP level differed significantly between the PL and non-PL groups at all perioperative time-points. The white blood cell count, neutrophil count, and CRP levels on postoperative day 7 significantly differed between the SSI and non-SSI cases in the PL group. The area under the curve (AUC) for CRP was greater than that of the other parameters. The neutrophil count was only effective as a marker in the non-PL group. The combination of two cutoff values (CRP: 3.7 mg/dL (PL group) and neutrophil count: 6172/μL (non-PL group)) presented high specificity (87.2%) and sensitivity (88.9%), while only one cutoff value (CRP: 2.9 mg/dL) had a specificity of 77.4% and sensitivity of 77.8%.

CONCLUSIONS

Approximately one-fifth of patients developed PL post-surgery, which was a risk factor for SSI, with constant high inflammation. Grouping based on PL and establishing diagnostic cutoff values are more appropriate than establishing only one cutoff value for overall cases.

Preoperative lymphocyte percentage and neutrophil-lymphocyte ratio are useful predictors of 30-day postoperative complications after lumbar fusion

Background:

Lymphocyte percentage/count, platelet-lymphocyte ratio (PLR), and neutrophil-lymphocyte ratio (NLR) have shown prognostic significance in patients with cancer, stroke, and following cardiac surgery. However, the utility of these blood parameters for assessing the 30-day postoperative risk for lumbar fusion complications has not been established.

Methods:

In this single-center-single-surgeon retrospective series, 77 consecutive patients underwent one- or two-level lumbar fusion. Lymphocyte percentage/count, PLR, and NLR were investigated as predictors of 30-day postoperative complications.

Results:

Ten of 77 patients had postoperative complications. A unit increase in NLR and lymphocyte percentage was significantly associated with a 23% increase and 7% decrease, respectively, in the odds of a complication occurring. Preoperative NLR ≥ 2.32 and lymphocyte percentage ≤ 29.5% significantly discriminated between the “complication” and “no-complication” groups.

Conclusion:

Patients with a preoperative lymphocyte percentage of ≤29.5% and/or NLR ≥2.32 should be closely monitored as high-risk groups susceptible to 30-day postoperative complications after lumbar fusion.

Interleukin-6 as inflammatory marker of surgical site infection following spinal surgery

BACKGROUND

In order to elucidate whether serum inflammatory markers identify patients with local surgical site infection(SSI) as underlying disease for recurrent or new symptomatology following spine surgery, we evaluated the diagnostic potential of interleukin-6(IL-6) as a marker of SSI. The diagnostic significance of IL-6 was compared to the standard serum inflammatory markers C-reactive protein(CRP) and white blood cell count (WBCC).

METHOD

Ninety-eight consecutive patients with readmission due to recurrent or new symptomology after spinal surgery of degenerative spine disorders entered the study. Baseline patients' characteristics and the abovementioned inflammatory markers were collected, and arithmetical means with standard deviation, area under the curve (AUC), thresholds, sensitivity, specificity, positive(+)likelihood ratio (LR), and negative(-)LR with corresponding 95% confidence interval(95%CI) were calculated and correlated with presence or absence of SSI.

RESULTS

Nine patients suffered from a SSI, whereas the remaining 89 patients had a recurrent/adjacent-segment degenerative disorder without evidence of infection. The most significant parameter for diagnosing a SSI was serum IL-6 (cut-off value > 15.3 pg/ml, AUC = 0.954, SE = 85.7%, SP = 97.3%), followed by CRP (cut-off value = 0.8 mg/dl, AUC = 0.916, SE = 88.9%, SP = 84.5%) CONCLUSIONS: In the case of recurrent or new symptomatology following spinal surgery, serum IL-6 has the highest diagnostic potential for diagnosing spinal SSI.

Thoracic surgery during the coronavirus disease 2019 (COVID-19) pandemic in Madrid, Spain: single-centre report

OBJECTIVES

We reviewed the incidence of coronavirus disease 2019 cases and the postoperative outcomes of patients who had thoracic surgery during the beginning and at the highest point of transmission in our community.

METHODS

We retrospectively reviewed patients who had undergone elective thoracic surgery from 12 February 2020 to 30 April 2020 and were symptomatic or tested positive for severe acute respiratory syndrome coronavirus 2 infection within 14 days after surgery, with a focus on their complications and potential deaths.

RESULTS

Out of 101 surgical procedures, including 57 primary oncological resections, 6 lung transplants and 18 emergency procedures, only 5 cases of coronavirus disease 2019 were identified, 3 in the immediate postoperative period and 2 as outpatients. All 5 patients had cancer; the median age was 64 years. The main virus-related symptom was fever (80%), and the median onset of coronavirus disease 2019 was 3 days. Although 80% of the patients who had positive test results for severe acute respiratory syndrome coronavirus 2 required in-hospital care, none of them were considered severe or critical and none died.

CONCLUSIONS

These results indicate that, in properly selected cases, with short preoperative in-hospital stays, strict isolation and infection control protocols, managed by a dedicated multidisciplinary team, a surgical procedure could be performed with a relatively low risk for the patient.

Clinical course of coronavirus disease 2019 in 11 patients after thoracic surgery and challenges in diagnosis

OBJECTIVES

To illustrate the clinical course and difficulties in early diagnosis of coronavirus disease 2019 (COVID-19) in patients after thoracic surgery.

METHODS

We retrospectively analyzed the clinical course of the first 11 patients diagnosed with COVID-19 after thoracic surgery in early January 2020. Postoperative clinical, laboratory, and radiologic records and the time line of clinical course were summarized. Potential prognostic factors were evaluated.

RESULTS

In the 11 confirmed cases (3 female, 8 male), median days from symptom onset to case detection was 8. Insidious symptom onset and misinterpreted postoperative changes on chest computed tomography (CT) resulted in delay in diagnosis. There were 3 fatalities due to respiratory failure, whereas 4 severe and 4 mild cases recovered and were discharged. All patients had once experienced leukocytosis and eosinopenia. Remittent fever and resected lung segments ≥5 were associated with fatality.

CONCLUSIONS

The case fatality rate of postsurgical patients subsequently diagnosed with COVID-19 was 27.3%. Insidious symptom onset, postoperative leukocytosis with lymphopenia, and postsurgical CT changes overshadowed the early signs of viral pneumonia. Dynamic symptom monitoring, serial chest CTs, and tests for viral RNA and serum antibody improve the chance for prompt detection of COVID-19. Consideration should be given to preadmission and preoperative screening and strict contact isolation during the postoperative period.

Third day laboratory follow-up: mandatory for surgical site infections of tibial plateau fractures

INTRODUCTION

Tibial plateau fractures are common fractures in adults and can be extremely challenging for surgeons. State-of-the-art therapy is open reduction and internal fixation (ORIF), although major complications of ORIF are surgical site infections (SSIs). This is especially critical on the proximal tibia, which is only sparsely covered by soft tissue and has a close relation to the knee joint. We analyzed SSIs after ORIF to correlate established laboratory parameters to the occurrence of SSIs.

METHODS

A monocentric case-control study in a Level 1 Trauma Center was conducted. Data were acquired from electronic medical records from 2011 until 2016. White blood cell count (WBC) and C-reactive protein (CRP) were used as laboratory parameters and statistically analyzed.

RESULTS

In total, 97 patients were included, with four patients suffering from SSIs. Patients with SSIs had a significantly increased WBC count and CRP levels on the third postoperative day. Infection was diagnosed after rehospitalization, 12 ± 4 weeks after initial surgery. Furthermore, a large bony destruction through trauma coincides with a rise of WBC count with no influence on CRP level.

CONCLUSION

We highly recommend a laboratory analysis with WBC count and CRP on the third day after ORIF. Patients with a CRP level above 100 mg/l should be closely watched, even if laboratory parameters few days later are adequate-since a one-time increase above this landmark might be a hint regarding the development of a SSI.

Lymphocyte Count at 4 Days Postoperatively: A Reliable Screening Marker for Surgical Site Infection After Posterior Lumbar Decompression Surgery

STUDY DESIGN

Case-control study.

OBJECTIVE

To identify laboratory markers for surgical site infection (SSI) in posterior lumbar decompression surgery, which are not affected by operative factors, and to determine the diagnostic cutoffs of these markers.

SUMMARY OF BACKGROUND DATA

Numerous laboratory markers are used for the early detection of SSI; however, these markers may be affected by operative factors.

METHODS

The study included 182 participants. They were divided into an SSI group (patients who developed deep SSI; n = 8) and a no-SSI group (n = 174). We reviewed data on the C-reactive protein level and total white blood cell count and differential count before posterior lumbar decompression surgery and 1 and 4 days postoperatively. We determined which markers differed significantly between the groups and identified the markers that were not affected by operative factors (operative time, intraoperative blood loss, and number of operative segments) in the no-SSI group. We then determined the diagnostic cutoffs of these unaffected markers using receiver operating characteristic curves.

RESULTS

We identified the lymphocyte percentage at 4 days postoperatively (cutoff, <19.4%; sensitivity, 80.0%; specificity, 62.5%; area under the curve, 0.78) and lymphocyte count at 4 days postoperatively (cutoff, <1010/μL; sensitivity, 93.7%; specificity, 62.5%; area under the curve, 0.78) as reliable markers.

CONCLUSION

Lymphocyte percentage and count at 4 days postoperatively are reliable markers for SSI after posterior lumbar decompression surgery. Lymphocyte count at 4 days postoperatively can be considered as a superior marker for screening because it has a high sensitivity and can be measured early.

LEVEL OF EVIDENCE

4.