Inpatient Outcomes in Dialysis-dependent Patients Undergoing Elective Lumbar Surgery for Degenerative Lumbar Disease

Adjusting the RAPID score with 2 additional variables significantly increases its predictive value in patients with empyema

Pleural empyema is a serious condition leading to a significant burden on health care systems due to protracted hospitalisations. Treatment ranges from non-surgical interventions such as antibiotic therapy and chest tube placement to thoracoscopic or open surgery. Various risk factors which impact outcomes have been investigated. The RAPID (renal, age, purulence, infection source, and dietary factors) score is a clinical risk score which identifies patients at risk of death and may be used to formulate individual treatment strategies accordingly. All patients undergoing surgical interventions for empyema at a major tertiary medical centre in Germany from 2017 to 2020 were analysed. The aim was to identify perioperative risk factors which significantly impact treatment outcomes but are currently not included in the RAPID score. 245 patients with pleural empyema surgically treated at the Department of General, Visceral and Thoracic Surgery at the University Medical Centre, Hamburg, Germany (admitted from January 2017 to April 2020) were retrospectively analysed. All patients which received either minimally invasive or open thoracic surgery were included. Epidemiological as well as perioperative data was analysed to identify risk factors which impact long-term overall outcomes. 90-day mortality rate was the primary endpoint. The mean age was 59.4 years with a bimodal distribution. There was a male predominance across the cohort (71.4% compared to 28.6%), with no significant differences across ages below or above 60 years. 53 (21.6%) patients died within the first 90 days. Diabetes type 1 and 2, renal replacement therapy, immunosuppression, postoperative bleeding, intraoperative transfusion as well as microbiologically confirmed bacterial invasion of the pleura all led to higher mortality rates. Higher RAPID scores accurately predicted higher 90-day mortality rates. Modifying the RAPID score by adding the comorbidities diabetes and renal replacement therapy significantly increased the predictive value of the score. We demonstrated various perioperative and patient related risk-factors not included in the RAPID score which negatively impact postoperative outcome in patients receiving surgical treatment for pleural empyema. These should be taken into consideration when deciding on the best course of treatment. If confirmed in a prospective study including non-surgical patients with a significantly larger cohort, it may be worth considering expanding the RAPID score to include these.

Postoperative Complications and Survival Rate in Hemodialysis-Dependent Patients Undergoing Cervical Spine Surgery

Introduction

Spine surgery is challenging in hemodialysis (HD)-dependent patients owing to their poor general condition. However, postoperative complications and the mortality and survival rates have not been specifically evaluated in a wide series. This study aimed to elucidate postoperative complications and the survival rate in cervical spine surgery in HD patients.

Methods

This study included 109 HD patients (70 men, 39 women) who had undergone cervical spine surgery between July 1996 and May 2018. Based on radiological diagnosis, we divided them into the destructive spondyloarthropathy (DSA) and non-DSA groups. We investigated the causes of hemodialysis, postoperative complications, postoperative inpatient mortality rate, and survival rate.

Results

The DSA and non-DSA groups included 100 surgeries in 89 patients and 21 surgeries in 20 patients, respectively. The mean age at surgery was 62.9 years for the DSA and 55.9 years for the non-DSA group (P=0.97). The DSA group had a shorter hemodialysis period at surgery compared with the non-DSA group (21.7 vs. 26.5 years, P<0.05). The two most common causes of HD in both groups were chronic glomerulonephritis (DSA, 45%; non-DSA, 57.1%) and diabetes (DSA, 11%; non-DSA, 14.5%). Postoperative complications were observed in 23% (23/100) and 19% (4/21) of surgeries in the DSA and non-DSA groups, respectively (P=0.782). The total in-hospital mortality rate was 2.5% (3/121). The 1-, 3-, 5-, and 10-year postoperative survival rates of all patients were 89.6%, 75.5%, 67.1%, and 44.7%, respectively. The survival rates did not depend on the group (DSA vs. non-DSA), pre- and postoperative Japanese Orthopedic Association score for cervical myelopathy, hemodialysis period, sex, and age (P>0.05). However, significantly low survival rates were observed in HD caused by diabetes compared with that by chronic glomerulonephritis (P<0.001) and other causes (P<0.001).

Conclusions

Cervical spine surgery in HD patients is associated with postoperative complications. The postoperative survival rate was found to be low if the cause of hemodialysis was diabetes.

Morbidity after elective surgery in patients on chronic dialysis: a systematic review and meta-analysis

BACKGROUND

Patients on chronic dialysis are at increased risk of postoperative mortality following elective surgery compared to patients with normal kidney function, but morbidity outcomes are less often reported. This study ascertains the excess odds of postoperative cardiovascular and infection related morbidity outcomes for patients on chronic dialysis.

METHODS

Systematic searches were performed using MEDLINE, Embase and the Cochrane Library to identify relevant studies published from inception to January 2020. Eligible studies reported postoperative morbidity outcomes in chronic dialysis and non-dialysis patients undergoing major non-transplant surgery. Risk of bias was assessed using the Newcastle-Ottawa Scale and the certainty of evidence was summarised using GRADE. Random effects meta-analyses were performed to derive summary odds estimates. Meta-regression and sensitivity analyses were performed to explore heterogeneity.

RESULTS

Forty-nine studies involving 10,513,934 patients with normal kidney function and 43,092 patients receiving chronic dialysis were included. Patients on chronic dialysis had increased unadjusted odds of postoperative cardiovascular and infectious complications within each surgical discipline. However, the excess odds of cardiovascular complications was attenuated when odds ratios were adjusted for age and comorbidities; myocardial infarction (general surgery, OR 1.83 95% 1.29-2.36) and stroke (general surgery, OR 0.95, 95%CI 0.84-1.06). The excess odds of infectious complications remained substantially higher for patients on chronic dialysis, particularly sepsis (general surgery, OR 2.42, 95%CI 2.12-2.72).

CONCLUSION

Patients on chronic dialysis are at increased odds of both cardiovascular and infectious complications following elective surgery, with the excess odds of cardiovascular complications attributable to being on dialysis being highest among younger patients without comorbidities. However, further research is needed to better inform perioperative risk assessment.

Inpatient Outcomes in Dialysis Dependent Patients Undergoing Elective Cervical Spine Surgery for Degenerative Cervical Conditions

STUDY DESIGN

Retrospective cohort study.

OBJECTIVE

To evaluate inpatient outcomes in dialysis dependent patients undergoing elective cervical spine surgery.

METHODS

A total of 1605 dialysis dependent patients undergoing elective primary or revision cervical spine surgery for degenerative conditions were identified from the National Inpatient sample from 2002 to 2012 and compared to 1 450 642 nondialysis-dependent patients undergoing the same procedures. The National Inpatient Sample is a de-identified database; thus, no institutional review board approval was needed.

RESULTS

Dialysis dependence was associated with higher inpatient mortality rates (7.5% vs 1.9%; P < .001) as well as both major (17.3% vs 0.6%; P < .001) and minor (36.8% vs 10.5%; P < .001) complication rates as compared with nondialysis-dependent patients. Dialysis-dependent patients had substantially increased mean lengths of stay (9.8 days compared with 2.0 days; P < .001) and total hospital charges ($141 790 compared with $46 562; P < .001).

CONCLUSION

Dialysis-dependence is associated with drastically increased complication rates, risk of mortality, and represent a significant financial and psychosocial burden to patients undergoing elective cervical spine surgery. Both surgeons and patients should be aware of these risks while planning elective surgeries.

Postoperative mortality in patients on chronic dialysis following elective surgery: A systematic review and meta-analysis

RATIONALE & OBJECTIVE

The prognostic significance of dialysis-dependent end-stage kidney disease on postoperative mortality is unclear. This study aims to estimate the odds of postoperative mortality in patients receiving chronic dialysis undergoing elective surgery compared to patients with normal kidney function, and to examine the influence of comorbidities on the excess mortality risk.

METHODS

A systematic search of studies published up to January 2020 was conducted using MEDLINE, EMBASE and CENTRAL databases. Eligible studies reported postoperative 30-day or in-hospital mortality in chronic dialysis patients compared to patients with normal kidney function undergoing elective surgery. Two investigators independently reviewed all abstracts and performed risk of bias assessments using the Newcastle-Ottawa Scale. Quality of evidence was summarised in accordance with GRADE methodology (grading of recommendations, assessment, development and evaluation). Relative mortality risk estimates were obtained using random effects meta-analysis. Heterogeneity was explored using meta-regression. (PROSPERO CRD42017076565).

RESULTS

Forty-nine studies involving 41, 822 chronic dialysis and 10, 476, 321 non-dialysis patients undergoing elective surgery were included. Patients on chronic dialysis had a greatly increased postoperative mortality odds compared to patients with normal kidney function. The excess risk ranged from OR 10.8 (95%CI 7.3-15.9) following orthopaedic surgery to OR 4.0 (95%CI 3.2-4.9) after vascular surgery. Adjustment for age and comorbidity attenuated the excess odds but remained higher for patients on chronic dialysis, irrespective of surgical discipline. Meta-regression analysis demonstrated an inverse linear relationship between excess mortality risk and study-level mean age (slope -0.06; P = 0.001) and diabetes prevalence (slope -0.02; p = 0.001).

CONCLUSIONS

Patients on chronic dialysis have an increased odds for postoperative mortality following elective surgery across all surgical disciplines. This relationship is consistent among all studies, with the excess postoperative mortality attributable to end-stage kidney disease and chronic dialysis treatment may be lower among older patients with diabetes.

Perioperative outcomes and risk assessment in dialysis patients: current knowledge and future directions

Perioperative medicine is rapidly emerging as a key discipline to address the specific needs of high-risk surgical groups, such as those on chronic dialysis. Crude hospital separation rates for chronic dialysis patients are considerably higher than patients with normal renal function, with up to 15% of admission being related to surgical intervention. Dialysis dependency carries substantial mortality and morbidity risk compared to patients with normal renal function. This group of patients has a high comorbid burden and complex medical need, making accurate perioperative planning essential. Existing perioperative risk assessment tools are unvalidated in chronic dialysis patients. Furthermore, they fail to incorporate important dialysis treatment-related characteristics that could potentially influence perioperative outcomes. There is a dearth of information on perioperative outcomes of Australasian dialysis patients. Current perioperative outcome estimates stem predominantly from North American literature; however, the generalisability of these findings is limited, as the survival of North American dialysis patients is significantly inferior to their Australasian counterparts and potentially confounds reported perioperative outcomes; let alone regional variation in surgical indication and technique. We propose that data linkage between high-quality national registries will provide more complete data with more detailed patient and procedural information to allow for more informative analyses to develop and validate dialysis-specific risk assessment tools.

Thoracic Kyphotic Deformity Secondary to Old Pseudomonas aeruginosa Spondylodiscitis in an Immunocompromised Patient With Persistent Infection Foci-A Case Report

Background

Kyphosis secondary to pyogenic spondylodiscitis is rare and its management can be very challenging.

Methods

In this report, we present the case of a 28-year-old woman, with past history of type 1 diabetes and kidney failure on hemodialysis. Her current complaint is chronic middle and low back pain with kyphotic attitude. She had undergone posterior fixation for T12 fracture 3 years earlier, which was complicated by surgical site infection to Pseudomonas aeruginosa, with secondary kyphosis proximally. X-ray showed a 64° kyphosis with complete fusion between T8 and T10, and MRI showed persistent infection foci.

Results

The patient underwent a pedicle subtraction osteotomy at the level of T9 with instrumentation from T5 to L1. Thoracic kyphosis was corrected to 39°. Samples taken from the remaining collections returned positive for multidrug-resistant Pseudomonas aeruginosa, and the patient was kept on intravenous antibiotic (Colistine) for 2 months. She could walk on day 1, with a satisfactory clinical and radiological result at 3 years.

Conclusions

Literature is sparse on the management of post-pyogenic infection kyphosis in immunocompromised patients. The current case shows that aggressive correction techniques such as pedicle subtraction osteotomy can be performed in such cases but within a multidisciplinary team to deal simultaneously with the different issues of the fragile patient.

Impact of Dialysis on 30-Day Outcomes After Spinal Fusion Surgery for Pathologic Fractures: Insights from a National Quality Registry

BACKGROUND

Patients with chronic renal failure undergoing hemodialysis have been shown to have poor overall health, osteoporosis, and altered bone metabolism. However, the impact of hemodialysis on patient outcomes after spinal fusion remains unknown. We sought to assess the effect of dialysis on 30-day perioperative and postoperative outcomes after cervical and lumbar fusion for pathologic compression fractures.

METHODS

We queried the National Surgical Quality Improvement Program from 2009 to 2016 for patients undergoing cervical or lumbar fusion for compression fractures. Three-to-one propensity score matching using sex, age, body mass index, and number of operated levels was used to match patients not undergoing dialysis with those undergoing dialysis. Multivariable conditional regression was used to identify the association between dialysis and 30-day clinical outcomes, after adjusting for confounders.

RESULTS

A total of 48,492 patients undergoing cervical fusion were identified; 156 (0.32%) of these were on dialysis. On multivariable regression, dialysis dependency was associated with increased operative time (regression coefficient [coef.], 15.93; 95% CI, 0.4-31.5; P = 0.045), length of stay (coef. 6.06; 95% CI, 4.64-7.48; P < 0.001), 30-day readmissions (odds ratio [OR], 1.07; 95% CI, 1.02-1.12; P = 0.009), any complications (OR 1.08; 95% CI, 1.03-1.13; P = 0.002), and serious complications (OR, 1.08; 95% CI, 1.02-1.14; P = 0.012). A total of 25,417 patients undergoing lumbar fusion were identified; 51 of these (0.2%) were on dialysis. On multivariable regression, dialysis dependency was associated with significantly higher length of stay (coef. 2.98; 95% CI, 1.28-4.68; P < 0.001).

CONCLUSIONS

Our analyses indicated that dialysis dependency is associated with poor perioperative and postoperative outcomes after cervical/lumbar fusion for pathologic compression fractures.

30-day Mortality Following Surgery for Spinal Epidural Abscess: Incidence, Risk Factors, Predictive Algorithm, and Associated Complications

STUDY DESIGN

Retrospective case-control study.

OBJECTIVE

To determine incidence and timing of mortality following surgery for spinal epidural abscess (SEA), identify risk factors for mortality, and identify complications associated with mortality.

SUMMARY OF BACKGROUND DATA

SEA is a serious condition with potentially devastating sequelae. There is a paucity of literature characterizing mortality following surgery for SEA.

METHODS

The National Surgical Quality Improvement Program (NSQIP) database was used. Patients with a diagnosis of SEA were included. A Cox proportional hazards model identified independent risk factors for 30-day mortality. A predictive model for mortality was created. Multivariate models identified postoperative complications associated with mortality.

RESULTS

There were 1094 patients included, with 40 cases of mortality (3.7%), the majority of which occurred within 2 weeks postoperatively (70%). Independent risk factors for 30-day mortality were age>60 years (hazard ratio [HR]: 2.147, P = 0.027), diabetes (HR: 2.242, P = 0.015), respiratory comorbidities (HR: 2.416, P = 0.037), renal comorbidities (HR: 2.556, P = 0.022), disseminated cancer (HR: 5.219, P = 0.001), and preoperative thrombocytopenia (HR: 3.276, P = 0.001). A predictive algorithm predicts a 0.3% mortality for zero risk factors up to 37.5% for 4 or more risk factors. A ROC area under curve (AUC) was 0.761, signifying a fair predictor (95% CI: 0.683-0.839, P < 0.001). Cardiac arrest (adjusted odds ratio [aOR]: 72.240, 95% confidence interval [CI]: 27.8-187.721, P < 0.001), septic shock (aOR: 15.382, 95% CI: 7.604-31.115, P < 0.001), and pneumonia (aOR: 2.84, 95% CI: 1.109-7.275, P = 0.03) were independently associated with mortality.

CONCLUSION

The 30-day mortality rate following surgery for SEA was 3.7%. Of the mortalities that occurred within 30 days of surgery, the majority occurred within 2 weeks. Independent risk factors for mortality included older age, diabetes, hypertension, respiratory comorbidities, renal comorbidities, metastatic cancer, and thrombocytopenia. Risk for mortality ranged from 0.3% to 37.5% based on number of risk factors. Septic shock, cardiac arrest, and pneumonia were associated with mortality.

LEVEL OF EVIDENCE

3.

Dialysis is an independent risk factor for perioperative adverse events, readmission, reoperation, and mortality for patients undergoing elective spine surgery

BACKGROUND CONTEXT

The prevalence of dialysis-dependent patients in the United States is growing. Prior studies evaluating the risk of perioperative adverse events for dialysis-dependent patients are either institutional cohort studies limited by patient numbers or administrative database studies limited to inpatient data.

PURPOSE

The present study uses a large, national sample with 30-day follow-up to investigate dialysis as risk factor for perioperative complications independent of patient demographics or comorbidities.

STUDY DESIGN/SETTING

This is a retrospective cohort study.

PATIENT SAMPLE

Patients undergoing elective spine surgery with or without dialysis from the 2005-2015 National Surgical Quality Improvement Program (NSQIP) database were included in the study.

OUTCOME MEASURES

Postoperative complications within 30 days and binomial reoperation, readmission, and mortality within 30 days were determined.

METHODS

The 2005-2015 NSQIP databases were queried for adult dialysis-dependent and dialysis-independent patients undergoing elective spinal surgery. Differences in 30-day outcomes were compared using risk-adjusted multivariate regression and coarsened exact matching analysis for adverse events, unplanned readmission, reoperation, and mortality. The percentage of complications occurring before versus after hospital discharge was also assessed. The authors have no financial disclosures related to the present study.

RESULTS

A total of 467 dialysis and 173,311 non-dialysis patients met the inclusion criteria. Controlling for age, gender, body mass index, functional status, and American Society of Anesthesiologists (ASA) class, dialysis patients were found to be at significantly greater odds of any adverse event (odds ratio [OR]=2.52 before, 2.17 after matching, p=<.001), major adverse event (OR=2.90 before, 2.52 after matching, p=<.001), and minor adverse event (OR=1.50 before matching, p=<.025, but not significantly different after matching). Further, dialysis patients were significantly more likely to return to the operating room (OR=2.77 before, 2.50 after matching, p=<.001), have unplanned readmissions (OR=2.73 before, 2.37 after matching, p=<.001), and die within 30 days (OR=3.77 before, 2.71 after matching, p=<.001). Adverse events occurred after discharge for 51.78% of non-dialysis patients and for 43.80% of dialysis patients.

CONCLUSIONS

Dialysis patients undergoing elective spine surgery are at significantly higher risk of aggregated adverse outcomes, return to the operating room, readmission, and death than non-dialysis patients, even after controlling for patient demographics and overall health (as indicated by ASA class). These differences need to be considered when determining treatment options. Additionally, with bundled payments expected in spine surgery, physicians and hospitals need to account for increased costs and liabilities when working with dialysis patients.

Obstructive Sleep Apnea in Elective Spine Surgery: National Prevalence and Inpatient Outcomes

STUDY DESIGN

Retrospective cohort study.

OBJECTIVES

Epidemiologic studies suggest that the prevalence of moderate to severe obstructive sleep apnea (OSA) is increasing. OSA has been linked to increased rates of postoperative complications following surgery. Large studies, however, regarding surgical outcomes in this patient population, particularly in the spine literature, are limited. Consequently, the purpose of this study was to assess the prevalence of and postoperative risks conferred by OSA in the elective spine population.

METHODS

Using data from the National Inpatient Sample from 2008 to 2012, an estimated 56 372 (5.1%) patients with OSA undergoing elective cervical and thoracolumbar spine surgery were selected and compared to 1 052 837 patients without OSA undergoing the same procedures. Our primary outcome measures included postoperative complication rates, inpatient mortality, length of stay, and total hospital charges.

RESULTS

Patients with OSA were, on average 2.6 years older than those without OSA (P < .001) and had a higher comorbidity burden. The prevalence of OSA increased between 2008 and 2012 from 3.5% to 6.8%; P < .001. OSA was associated with a 3-fold increase in major complications (P < .001) and was confirmed as an independent risk factor for major complications based on multivariate analysis (odds ratio [OR] = 2.82; 95% CI = 2.59-2.79; P < .001). Rates of deep venous thrombosis were doubled in patients with OSA. OSA was determined to be an independent predictor of pulmonary complications (OR = 2.69; 95% CI = 2.59-2.79; P < .001). OSA did not increase the risk of postoperative mortality.

CONCLUSIONS

Patients with OSA often have multiple concomitant comorbidities and consequently are at increased risk of experiencing a more difficult postoperative course following elective spine surgery. Specifically, increased risks of pulmonary complications and deep venous thrombosis should be anticipated.

Postoperative Complications in Dialysis-Dependent Patients Undergoing Elective Decompression Surgery Without Fusion or Instrumentation for Degenerative Cervical or Lumbar Lesions

STUDY DESIGN

This was a single-institute retrospective study.

OBJECTIVE

To evaluate postoperative complications in dialysis-dependent patients undergoing elective cervical and lumbar decompression surgery.

SUMMARY OF BACKGROUND DATA

Spinal surgery in dialysis-dependent patients is very challenging due to the high risk of serious postoperative complications and mortality associated with their fragile general condition. However, the outcome of decompression surgery alone has not been evaluated in such patients.

METHODS

An electronic medical record review showed that 338 and 615 patients had undergone cervical and lumbar spine posterior decompression, respectively. Among them, 48 and 42, respectively were dialysis-dependent patients. Postoperative complications were compared between dialysis-dependent and non-dialysis-dependent patients.

RESULTS

Among patients who underwent cervical decompression, the rate of perioperative blood transfusion in dialysis-dependent patients (14.6%) was significantly higher than that in non-dialysis-dependent patients (0.7%). No severe complications or mortality occurred in association with cervical decompression. The incidence of postoperative complications in dialysis-dependent patients (6.3%) was not significantly different from that in non-dialysis-dependent patients (4.1%). Among patients who underwent lumbar decompression, the rate of perioperative transfusion in dialysis-dependent patients (11.9%) was also significantly higher than that in non-dialysis-dependent patients (0.7%). With respect to severe complications among patients who underwent lumbar decompression, cerebral hemorrhage occurred in one dialysis-dependent patient, and no mortality occurred. The incidence of postoperative complications in dialysis-dependent patients (9.2%) was not significantly different from that in non-dialysis-dependent patients (6.8%).

CONCLUSION

Among patients who underwent posterior decompression alone for cervical or lumbar lesions, the rate of perioperative blood transfusion was significantly higher in dialysis-dependent than in non-dialysis-dependent patients. However, the postoperative rates of severe complications and mortality were not significantly different between the two groups. Therefore, decompression surgery alone is considered a rational surgical method with less invasiveness for dialysis-dependent patients with a fragile general condition.

LEVEL OF EVIDENCE

3.

Discriminative Ability for Adverse Outcomes After Surgical Management of Hip Fractures: A Comparison of the Charlson Comorbidity Index, Elixhauser Comorbidity Measure, and Modified Frailty Index

OBJECTIVES

The Charlson comorbidity index (CCI), Elixhauser comorbidity measure (ECM), and modified frailty index (mFI) have been associated with mortality after hip fracture. The present study compares the clinically informative discriminative ability of CCI, ECM, and mFI, as well as demographic characteristics for predicting in-hospital adverse outcomes after surgical management of hip fractures.

METHODS

Patients undergoing hip fracture surgery were selected from the 2013 National Inpatient Sample. The discriminative ability of CCI, ECM, and mFI, as well as demographic factors for adverse outcomes were assessed using the area under the curve analysis from receiver operating characteristic curves. Outcomes included the occurrence of any adverse event, death, severe adverse events, minor adverse events, and extended hospital stay.

RESULTS

In total, 49,738 patients were included (mean age: 82 years). In comparison with CCI and mFI, ECM had the significantly largest discriminative ability for the occurrence of all outcomes. Among demographic factors, age had the sole or shared the significantly largest discriminative ability for all adverse outcomes except extended hospital stay. The best performing comorbidity index (ECM) outperformed the best performing demographic factor (age) for all outcomes.

CONCLUSION

Among both comorbidity indices and demographic factors, the ECM had the best overall discriminative ability for adverse outcomes after surgical management of hip fractures. The use of this index in correctly identifying patients at risk for postoperative complications may help set appropriate patient expectations, assist in optimizing prophylaxis regimens for medical management, and adjust reimbursements. More widespread use of this measure for hip fracture studies may be appropriately considered.

LEVEL OF EVIDENCE

Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.