Risk factors for reintubation after anterior cervical discectomy and fusion surgery: evaluation of three observational data sets

The Postoperative Airway Compromise Score-First Steps to Developing a Postoperative Tool for the Assessment of Upper Airway-Related Complications Following Anterior Cervical Spine Surgery

BACKGROUND

Acute upper airway compromise is a rare but catastrophic complication after anterior cervical discectomy and fusion. This study aims to develop a score to identify patients at risk of acute postoperative airway compromise (PAC).

METHODS

Potential risk factors for acute PAC were selected by a modified Delphi process. Ten patients with acute PAC were identified of 1466 patients who underwent elective anterior cervical discectomy and fusion between July 2014 and May 2019. A comparison group was created by a randomized selection process (non-PAC group). Factors associated with PAC and a P value of < 0.10 were entered into a logistic regression model and coefficients contributed to each risk factor's overall score. Calibration of the model was evaluated using the Hosmer-Lemeshow goodness-of-fit test. Quantitative discrimination was calculated, and the final model was internally validated with bootstrap sampling.

RESULTS

We identified 18 potential risk factors from our Delphi process, of which 6 factors demonstrated a significant association with airway compromise: age >65 years, current smoking status, American Society of Anesthesiologists class >2, history of a bleeding disorder, surgery of upper subaxial cervical spine (above C4), and duration of surgery >179 minutes. The final prediction model included 5 predictors with very strong performance characteristics. These 5 factors formed the PAC score, with a range from 0 to 100. A score of 20 yielded the greatest balance of sensitivity (80%) and specificity (88%).

CONCLUSIONS

The acute PAC score demonstrates strong performance characteristics. The PAC score might help identify patients at risk of upper airway compromise caused by surgical site abnormalities.

Postoperative Airway Management after Anterior Cervical Spine Surgery: Retrospective Neurosurgical Multicenter Study

Airway complications that occur after anterior cervical spine surgery pose a life-threatening risk, which encompasses complications including prolonged intubation, unplanned reintubation, and/or necessity of tracheostomy. The present study aimed to identify the surgical risks associated with postoperative airway complications in neurosurgical training institutes. A retrospective, multicenter, observational review of data from 365 patients, who underwent anterior cervical spine surgery between 2018 and 2022, at three such institutes was carried out. Postoperative airway complication was defined as either the need for prolonged intubation on the day of surgery or the need for unplanned reintubation. The perioperative medical information was obtained from their medical records. The average age of the cohort was over 60 years, with males comprising approximately 70%. Almost all surgeries predominantly involved anterior cervical discectomy and fusion or anterior cervical corpectomy and fusion, with most surgeries occurring at the level of C5/6. In total, 363 of 365 patients (99.5%) were extubated immediately after surgery, and the remaining two patients were kept under intubation because of the risk of airway complications. Of the 363 patients who underwent extubation immediately after surgery, two (0.55%) required reintubation because of postoperative airway complications. Patients who experienced airway complications were notably older and exhibited a significantly lower body mass index. The results of this study suggested that older and frailer individuals are at an elevated risk for postoperative airway complications, with immediate postoperative extubation generally being safe but requiring careful judgment in specific cases.

Risk of Dysphagia and Dysphonia in Patients With Prior Thyroidectomy Undergoing Anterior Cervical Discectomy and Fusion

STUDY DESIGN

Retrospective cohort study using PearlDiver database.

OBJECTIVES

To evaluate the effect of prior thyroidectomy on complications of Anterior Cervical Discectomy and Fusion (ACDF) surgery.

METHODS

PearlDiver was used to identify patients without prior dysphagia or dysphonia undergoing ACDF between the years 2010-2020Q1. Patients with and without prior thyroidectomy were matched by levels of fusion, alcohol use, and gastroesophageal reflux disease in a 1:5 ratio. Postoperative outcomes were assessed for each cohort with multivariable logistic regression, controlling for age, sex, and Elixhauser Comorbidity Index.

RESULTS

Between 2010 and 2019, matched cohorts of 792 ACDF patients with prior thyroidectomy and 3960 ACDF only patients were included in the study. Of patients with previous thyroidectomy undergoing ACDF, 16.3% experienced dysphagia at 1-year compared with 10.6% for patients undergoing ACDF only (aOR=1.39, P=.004). Patients with previous thyroidectomy also had higher odds of dysphonia at 1-year following ACDF, as compared to patients with ACDF alone (2.7% vs 1.2%, aOR=1.74, P= .048). Patients undergoing ACDF with prior thyroidectomy did not have increased risk of revision at 1 year (aOR=1.10, P=.698), 2 years (aOR=1.16, P=.457), or 5 years (aOR=1.20, P=.255) following surgery. There were no differences in postoperative opioid utilization rates at 1 month (aOR=2.07, P=.138), 3 months (aOR=2.45, P=.095), 6 months (aOR=1.34, P=.520), and 12 months (aOR=1.69, P=.202). Prior thyroidectomy was not associated with reintubation following ACDF (P=.995).

CONCLUSIONS

Patients with prior thyroidectomy undergoing ACDF surgery experience increased odds of dysphagia and dysphonia at 1-year follow-up compared to those without prior thyroidectomy.

Incidence and Outcome of Reintubation in the Postanesthesia Care Unit: A Single-Center, Retrospective, Observational Matched Cohort Study in China

PURPOSE

To investigate the incidence and outcome of reintubation after planned extubation (RAP) in the postanesthesia care unit (PACU) in China.

DESIGN

A single-center, retrospective, 1:2 matched cohort study following the Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) Statement.

METHODS

Among 121,965 patients in the PACU, 14 patients with RAP were included in this study from January 1, 2017 to December 31, 2019. PACU length of stay, postoperative length of stay in hospital, inpatient healthcare costs, and outcomes were compared between the RAP and the matched groups.

FINDINGS

The incidence of RAP was 0.0115%. After propensity score matching, there were no statistically significant differences in age, sex, body mass index (BMI), elective/nonelective procedure, surgical classification, American Society of Anesthesiologists physical status, the duration of anesthesia, or the duration of surgical procedure between the two groups. PACU length of stay, postoperative length of stay in hospital, and inpatient healthcare costs significantly differed between the RAP group and the matched group (P < .01 for all). The percentage of patients with longer PACU length of stay in the RAP group was significantly higher than that in the matched group (92.86% vs 7.14%), with an odds ratio of 29.87 (95% confidence interval = 14.00-2,040.54, P < .001).

CONCLUSIONS

Despite its low incidence, RAP in the PACU may be associated with life-threatening and severe complications with longer PACU length of stay, unexpected intensive care unit admission, longer hospitalization length, longer postoperative length of stay in hospital, and increased inpatient health costs. Appropriate timing of extubation and monitoring in the PACU can effectively prevent the occurrence of RAP and improve patient prognosis.

Risk Factors for Unexpected Conversion From Ambulatory to Inpatient Admission Among One-level or Two-level ACDF Patients

STUDY DESIGN/SETTING

A retrospective observational study.

OBJECTIVE

The aim of this study was to investigate the factors associated with the conversion of patient status from ambulatory anterior cervical discectomy and fusion (ACDF) to inpatient.

SUMMARY OF BACKGROUND DATA

Surgeries are increasingly performed in an ambulatory setting in an era of rising healthcare costs and pressure to improve patient satisfaction. ACDF is a common ambulatory cervical spine surgery, however, there are certain patients who are unexpectedly converted from an outpatient procedure to inpatient admission and little is known about the risk factors for conversion.

MATERIALS AND METHODS

Patients who underwent one-level or two-level ACDF in an ambulatory setting at a single specialized orthopedic hospital between February 2016 to December 2021 were included. Baseline demographics, surgical information, complications, and conversion reasons were compared between patients with ambulatory surgery or observational stay (stay <48 h) and inpatient (stay >48 h).

RESULTS

In total, 662 patients underwent one-level or two-level ACDF (median age, 52 yr; 59.5% were male), 494 (74.6%) patients were discharged within 48 hours and 168 (25.4%) patients converted to inpatient. Multivariable logistic regression analysis demonstrated that females, low body mass index <25, American Society of Anesthesiologists classification (ASA) ≥3, long operation, high estimated blood loss, upper-level surgery, two-level fusion, late operation start time, and high postoperative pain score were considered independent risk factors for conversion to inpatient. Pain management was the most common reason for the conversion (80.0%). Ten patients (1.5%) needed reintubation or remained intubated for airway management.

CONCLUSIONS

Several independent risk factors for prolonged hospital stay after ambulatory ACDF surgery were identified. Although some factors are unmodifiable, other factors, such as procedure duration, operation start time, and blood loss could be potential targets for intervention. Surgeons should be aware of the potential for life-threatening airway complications in ambulatory-scheduled ACDF.

Airway Complications After Anterior Cervical Spine Surgery: Etiology and Risk Factors

STUDY DESIGN

Narrative Review.

OBJECTIVE

To provide an overview of etiology and risk factors of airway complications after anterior cervical spine surgery (ACSS).

METHODS

A search was performed in PubMed and adapted for use in other databases, including Embase, Cochrane Library, Cochrane Register of Controlled Trials, Health Technology Assessment database, and NHS Economic Evaluation Database.

RESULTS

81 full-text studies were reviewed. A total of 53 papers were included were included in the review and an additional four references were extracted from other references. 39 papers were categorized as etiology and 42 as risk factors.

CONCLUSIONS

Most of the literature on airway compromise after ACSS is level III or IV evidence. Currently, there are no systems in place to risk-stratify patients undergoing ACSS regarding airway compromise or guidelines on how to manage patients when these complications do occur. This review focused on theory, primarily etiology and risk factors.

An Artificial Intelligence Approach to Predicting Unplanned Intubation Following Anterior Cervical Discectomy and Fusion

STUDY DESIGN

Level III retrospective database study.

OBJECTIVES

The purpose of this study is to determine if machine learning algorithms are effective in predicting unplanned intubation following anterior cervical discectomy and fusion (ACDF).

METHODS

The National Surgical Quality Initiative Program (NSQIP) was queried to select patients who had undergone ACDF. Machine learning analysis was conducted in Python and multivariate regression analysis was conducted in R. C-Statistics area under the curve (AUC) and prediction accuracy were used to measure the classifier's effectiveness in distinguishing cases.

RESULTS

In total, 54 502 patients met the study criteria. Of these patients, .51% underwent an unplanned re-intubation. Machine learning algorithms accurately classified between 72%-100% of the test cases with AUC values of between .52-.77. Multivariable regression indicated that the number of levels fused, male sex, COPD, American Society of Anesthesiologists (ASA) > 2, increased operating time, Age > 65, pre-operative weight loss, dialysis, and disseminated cancer were associated with increased risk of unplanned intubation.

CONCLUSIONS

The models presented here achieved high accuracy in predicting risk factors for re-intubation following ACDF surgery. Machine learning analysis may be useful in identifying patients who are at a higher risk of unplanned post-operative re-intubation and their treatment plans can be modified to prophylactically prevent respiratory compromise and consequently unplanned re-intubation.

Disparities in Elective Spine Surgery for Medicaid Beneficiaries: A Systematic Review

STUDY DESIGN

Systematic review.

OBJECTIVES

We sought to synthesize the literature investigating the disparities that Medicaid patients sustain with regards to 2 types of elective spine surgery, lumbar fusion (LF) and anterior cervical discectomy and fusion (ACDF).

METHODS

Our review was constructed in accordance with Preferred Reporting Items and Meta-analyses (PRISMA) guidelines and protocol. We systematically searched PubMed, Embase, Scopus, CINAHL, and Web of Science databases. We included studies comparing Medicaid beneficiaries to other payer categories with regards to rates of LF and ACDF, costs/reimbursement, and health outcomes.

RESULTS

A total of 573 articles were assessed. Twenty-five articles were included in the analysis. We found that the literature is consistent with regards to Medicaid disparities. Medicaid was strongly associated with decreased access to LF and ACDF, lower reimbursement rates, and worse health outcomes (such as higher rates of readmission and emergency department utilization) compared to other insurance categories.

CONCLUSIONS

In adult patients undergoing elective spine surgery, Medicaid insurance is associated with wide disparities with regards to access to care and health outcomes. Efforts should focus on identifying causes and interventions for such disparities in this vulnerable population.

Respiratory Compromise After Anterior Cervical Spine Surgery: Incidence, Subsequent Complications, and Independent Predictors

STUDY DESIGN

Retrospective cohort study.

OBJECTIVE

Respiratory compromise (RC) is a rare but catastrophic complication of anterior cervical spine surgery (ACSS) commonly due to compressive fluid collections or generalized soft tissue swelling in the cervical spine. Established risk factors include operative duration, size of surgical exposure, myelopathy, among others. The purpose of this current study is to identify the incidence and clinical course of patients who develop RC, and identify independent predictors of RC in patients undergoing ACSS for cervical spondylosis.

METHODS

A large, prospectively-collected registry was used to identify patients undergoing ACSS for spondylosis. Patients with posterior cervical procedures were excluded. Baseline patient characteristics were compared using bivariate analysis, and multivariate analysis was employed to compare postoperative complications and identify independent predictors of RC.

RESULTS

298 of 52,270 patients developed RC (incidence 0.57%). Patients who developed RC had high rates of 30-day mortality (11.7%) and morbidity (75.8%), with unplanned reoperation and pneumonia the most common. The most common reason for reoperations were hematoma evacuation and tracheostomy. Independent patient-specific factors predictive of RC included increasing patient age, male gender, comorbidities such as chronic cardiac and respiratory disease, preoperative myelopathy, prolonged operative duration, and 2-level ACCFs.

CONCLUSION

This is among the largest cohorts of patients to develop RC after ACSS identified to-date and validates a range of independent predictors, many previously only described in case reports. These results are useful for taking preventive measures, identifying high risk patients for preoperative risk stratification, and for surgical co-management discussions with the anesthesiology team.

Artificial intelligence in predicting early-onset adjacent segment degeneration following anterior cervical discectomy and fusion

PURPOSE

Anterior cervical discectomy and fusion (ACDF) is a common surgical treatment for degenerative disease in the cervical spine. However, resultant biomechanical alterations may predispose to early-onset adjacent segment degeneration (EO-ASD), which may become symptomatic and require reoperation. This study aimed to develop and validate a machine learning (ML) model to predict EO-ASD following ACDF.

METHODS

Retrospective review of prospectively collected data of patients undergoing ACDF at a quaternary referral medical center was performed. Patients > 18 years of age with > 6 months of follow-up and complete pre- and postoperative X-ray and MRI imaging were included. An ML-based algorithm was developed to predict EO-ASD based on preoperative demographic, clinical, and radiographic parameters, and model performance was evaluated according to discrimination and overall performance.

RESULTS

In total, 366 ACDF patients were included (50.8% male, mean age 51.4 ± 11.1 years). Over 18.7 ± 20.9 months of follow-up, 97 (26.5%) patients developed EO-ASD. The model demonstrated good discrimination and overall performance according to precision (EO-ASD: 0.70, non-ASD: 0.88), recall (EO-ASD: 0.73, non-ASD: 0.87), accuracy (0.82), F1-score (0.79), Brier score (0.203), and AUC (0.794), with C4/C5 posterior disc bulge, C4/C5 anterior disc bulge, C6 posterior superior osteophyte, presence of osteophytes, and C6/C7 anterior disc bulge identified as the most important predictive features.

CONCLUSIONS

Through an ML approach, the model identified risk factors and predicted development of EO-ASD following ACDF with good discrimination and overall performance. By addressing the shortcomings of traditional statistics, ML techniques can support discovery, clinical decision-making, and precision-based spine care.

Risk Factors for Post-operative Planned Reintubation in Patients After General Anesthesia: A Systematic Review and Meta-Analysis

Background

The occurrence of postoperative reintubation (POR) in patients after general anesthesia (GA) is often synonymous with a poor prognosis in patients. This is the first review analyzing scientific literature to identify risk factors of POR after general anesthesia. The purpose of this study was to collect currently published studies to determine the most common and consistent risk factors associated with POR after GA.

Methods

We have retrieved all relevant research published before April 2021 from PubMed, Embase, Web of Science, and the Cochrane Library electronic databases. These studies were selected according to the inclusion and exclusion criteria. The Z test determined the combined odds ratio (OR) of risk factors. We used OR and its corresponding 95% confidence interval (CI) to identify significant differences in risk factors. The quality of the study was evaluated with the NOS scale, and meta-analysis was carried out with Cochrane Collaboration's Revman 5.0 software.

Results

A total of 10 studies were included, with a total of 7,789 recipients of POR. We identified 7 risk factors related to POR after GA: ASA ≥ 3 (OR = 3.58), COPD (OR = 2.09), thoracic surgery (OR = 17.09), airway surgery (OR = 9.93), head-and-neck surgery (OR = 3.49), sepsis (OR = 3.50), DVT (OR = 4.94).

Conclusion

Our meta-analysis showed that ASA ≥ 3, COPD, thoracic surgery, airway surgery, head-and-neck surgery, sepsis and DVT were associated with POR after GA.

Systematic Review Registration

https://www.crd.york.ac.uk/prospero/display_record.php?, Identifier: CRD42021252466.

Unplanned intubation after total hip and total knee arthroplasty: Assessing preoperative risk factors

OBJECTIVE

The purpose of this study is to assess preoperative patient attributes as risk factors for unplanned intubation after primary total knee and total hip arthroplasty.

METHODS

This was a retrospective analysis of data collected from the National Surgical Quality Improvement Program (NSQIP) database. Patients undergoing Total Hip Arthroplasty (THA) or Total Knee Arthroplasty (TKA) who experienced postoperative intubation were included in the study. A multivariate regression was used to assess preoperative characteristics as risk factors for postoperative intubation.

RESULTS

Multivariate regression determined that perioperative transfusion of packed RBC's, cardiac comorbidities, patients older than 73, dyspnea with moderate exertion, dyspnea while at rest, diabetes mellitus requiring medical therapy, pulmonary comorbidities, current dialysis usage, body mass index greater than 29.9, and current smoker within the last year were variables associated with an increased risk of unplanned intubation after THA. Additionally, multivariate regression determined that anemia, perioperative transfusion of packed RBC's, cardiac comorbidities, patients older than 73, dyspnea with moderate exertion, diabetes mellitus requiring medical therapy, pulmonary comorbidities, and current dialysis usage were associated with unplanned intubation after TKA.

CONCLUSION

This study identifies numerous risk factors for intubation after THA or TKA.

Neuroanesthesiology Update

This review summarizes the literature published in 2020 that is relevant to the perioperative care of neurosurgical patients and patients with neurological diseases as well as critically ill patients with neurological diseases. Broad topics include general perioperative neuroscientific considerations, stroke, traumatic brain injury, monitoring, anesthetic neurotoxicity, and perioperative disorders of cognitive function.

Neck angioedema after anterior cervical discectomy and fusion with coexistent epiglottic cyst

Background:

We present a case and reviewed the literature regarding airway obstruction and angioedema after an anterior cervical discectomy and fusion (ACDF).

Case Description:

A 60-year-old female with degenerative cervical myelopathy and a previously undiagnosed epiglottic cyst underwent a C5–C6 ACDF; notably, the anesthesiologist found an epiglottic cyst when the patient was first intubated. Two hours postoperatively, the patient acutely developed severe neck swelling with airway obstruction due to angioedema. She was immediately treated with hydrocortisone and required a tracheostomy. The edema decreased markedly in the next 12 h and by the 3^rd postoperative day it resolved. Three months later, she had no residual medical sequelae.

Conclusion:

Patients with epiglottic cysts who need cervical spine surgery should either first have the cyst treated or should be closely monitored postoperatively.

Life-threatening delayed arterial hemorrhage following anterior cervical spine surgery: A case report and literature review

Background

One of the most serious and potentially life-threatening adverse events associated with anterior cervical spine surgery is postoperative hematoma with acute airway obstruction. The causes of unpredicted delayed bleeding are, however, not fully elucidated. Here, we report a case of delayed arterial bleeding and sudden airway obstruction following a two-level ACDF.

Case Description

A 52-year-old male presented with the right paracentral disc herniations at the C4-C5 and C5-C6 levels. A two-level ACDF was performed. Notably, on the 5^th postoperative day, the patient developed an acute respiratory distress due to a large right lateral retrotracheal hematoma requiring emergency evacuation at the bedside. This was followed by formal ligation of a branch of the right superior thyroid artery in the operating room. In addition, an emergency tracheotomy was performed. By postoperative day 15, the tracheotomy was removed, and the patient was neurologically intact.

Conclusion

A superior thyroid artery hemorrhage should be suspected if a patient develops delayed neck swelling with or without respiratory decompensation several days to weeks following an ACDF. Notably, these hematomas should be immediately recognized and treated (i.e., decompression starting at the bedside and completed in the operating room) to prevent catastrophic morbidity or mortality.