Factors associated with an increased risk of perioperative cardiac arrest in emergent and elective craniotomy and spine surgery

Long-term survivability of surgical and nonsurgical management of spinal epidural abscess

BACKGROUND CONTEXT

Spinal epidural abscess (SEA) is a rare and life-threatening infection within the epidural space with significant functional impairment and morbidity. Active debate remains over whether to operate for SEAs, with limited existing data comparing the long-term survivability after surgical versus nonsurgical management.

PURPOSE

This study aims to determine the long-term survival of patients who underwent surgical and nonsurgical management for SEA.

STUDY DESIGN

Retrospective cohort study.

PATIENT SAMPLE

A total of 250 consecutive SEA patients.

OUTCOME MEASURES

Survival and mortality rates, complications.

METHODS

All patients treated at a tertiary medical center for a primary SEA from January 2000 to June 2020 are identified. Data collection is by retrospective chart review. Cox proportional hazards regression models are used for all survival analyses while controlling for potential confounding variables and with multiple testing corrections.

RESULTS

A total of 35 out of 250 patients died with an overall all-cause mortality of 14%. More than half of all deaths occurred within 90 days after treatment. The 90-day, 3-year, and 5-year survival rates are 92.8%, 89.2%, and 86.4%, respectively. Among surgery patients, the all-cause mortality was 13.07%, compared to 16.22% for medically-managed patients. Surgical treatment (decompression, fusion, debridement) significantly reduced the risk of death by 62.4% compared to medical therapy (p=.03), but surgery patients experienced a significantly longer mean length of stay (p=.01). Risk factors of short-term mortality included hypoalbuminemia (<3.5 g/dL), American Society of Anesthesiologists (ASA) 4+, and cardiac arrest. Risk factors of long-term mortality were immunocompromised state, elevated WBC count >12,000, sepsis, septic shock, ASA 4+, and cardiac arrest (p<.05). In terms of complications, surgically-managed patients experienced a higher proportion of deep vein thrombosis (p<.05).

CONCLUSIONS

The overall long-term survivability of SEA treatment is relatively high at (86% at 5-year) in this study. The following SEA mortality risk factors were identified: hypoalbuminemia (short-term), immunocompromised state (long-term), leukocytosis (long-term), sepsis and septic shock (long-term), ASA 4+ and cardiac arrest (overall). For primary SEA patients, surgical management may reduce mortality risk compared to nonsurgical management.

Management of Patients with Ischemic Heart Disease in Spine Surgery

In ischemic heart disease (IHD), the myocardium does not receive enough blood and oxygen. Although the IHD-related mortality rate is decreasing, the risk remains and is a major predictor of cardiac complications following noncardiac surgery. Given the increase in the older population, the number of patients with spinal diseases requiring surgery is increasing. Among these patients, those with underlying IHD or a high risk of cardiac complications before and after surgery are also increasing. Given that cardiac complications following spinal surgery are associated with delayed patient recovery and even death, spinal surgeons should be knowledgeable about overall patient management, including medication therapy in those at high risk of developing perioperative cardiac complications for successful patient care. Before surgery, the underlying medical conditions of patients should be evaluated. Patients with a history of myocardial infarction should be checked for a history of surgical treatments, and the anticoagulant dose should be controlled depending on the surgery type. In addition, the functional status of patients must be examined before surgery. Functional status can be assessed according to the metabolic equivalent of task (MET). More preoperative cardiac examinations are needed for patients who are unable to perform four METs in daily because of the high risk of postoperative cardiac complications. Patients with a history of IHD require appropriate preoperative management and further postoperative evaluation. When considering surgery, spinal surgeons should be knowledgeable about patient care before and after surgery.

Symptomatic Epidural Hematoma After Elective Cervical Spine Surgery: Incidence, Timing, Risk Factors, and Associated Complications

BACKGROUND

As the rate of elective cervical spine surgery increases, studies of complications may improve quality of care. Symptomatic postoperative cervical epidural hematomas (PCEH) are rare but result in significant morbidity. Because of their low incidence, the risk factors and complications associated with symptomatic PCEH remain unclear.

OBJECTIVE

To clarify the prevalence, timing, variables, and complications associated with PCEH following elective cervical spine surgery.

METHODS

Using the American College of Surgeons National Surgical Quality Improvement Program database, cervical spine surgeries performed between 2012 and 2016 were identified using Current Procedural Terminology codes. Symptomatic PCEH was defined as readmission or reoperation events specifically associated with International Classification of Diseases code diagnoses of postoperative hematoma within 30 d of index surgery. Multivariate models were created to assess the independent association of symptomatic PCEH with other postoperative complications.

RESULTS

There were 53233 patients included for analysis. The overall incidence of symptomatic PCEH was 0.4% (n = 198). Reoperation occurred in 158 cases (78.8%), of which 2 required a second reoperation (1.3%). The majority (91.8%) of hematomas occurred within 15 d of surgery. Multivariate analysis identified male gender, American Society of Anesthesiologists classes 3 to 5, bleeding disorder, increasing number of operative levels, revision surgery, dural repair, and perioperative transfusion as independent factors associated with PCEH. Upon controlling for those confounders, PCEH was independently associated with cardiac arrest, stroke, deep vein thrombosis, surgical site infection, and pneumonia.

CONCLUSION

Postoperative epidural hematomas requiring readmission or reoperation following elective cervical spine surgery occurred at an incidence of 0.4%. Symptomatic PCEHs are associated with increased rates of numerous major morbidities.

Risk of cardiovascular complications during non-cardiac surgery and preoperative cardiac evaluation

The preoperative evaluation of candidates to non-cardiac surgery requires a knowledge of factors related both to the type of surgery and to the risk of each patient, in order to predict the potential cardiovascular complications. Over the past several decades, the field of preoperative cardiac evaluation before non-cardiac surgery has evolved substantially on the basis of the current guidelines of international medical societies. The aim of this paper is to summarize available evidence on the risk of non-cardiac surgery, focusing on appropriate cardiovascular assessment prior to surgery.

Conducting polymer-based granular hydrogels for injectable 3D cell scaffolds

Injectable 3D cell scaffolds possessing both electrical conductivity and native tissue-level softness would provide a platform to leverage electric fields to manipulate stem cell behavior. Granular hydrogels, which combine jamming-induced elasticity with repeatable injectability, are versatile materials to easily encapsulate cells to form injectable 3D niches. In this work, we demonstrate that electrically conductive granular hydrogels can be fabricated via a simple method involving fragmentation of a bulk hydrogel made from the conducting polymer PEDOT:PSS. These granular conductors exhibit excellent shear-thinning and self-healing behavior, as well as record-high electrical conductivity for an injectable 3D scaffold material (~10 S m-1). Their granular microstructure also enables them to easily encapsulate induced pluripotent stem cell (iPSC)-derived neural progenitor cells, which were viable for at least 5 days within the injectable gel matrices. Finally, we demonstrate gel biocompatibility with minimal observed inflammatory response when injected into a rodent brain.

Intraoperative Cardiac Arrest During Adult Liver Transplantation: Incidence and Risk Factor Analysis From 7 Academic Centers in the United States

BACKGROUND

Intraoperative cardiac arrest (ICA) has a reported frequency of 1 in 10,000 anesthetics but has a much higher estimated incidence in orthotopic liver transplantation (OLT). Single-center studies of ICA in OLT are limited by small sample size that prohibits multivariable regression analysis of risks.

METHODS

Utilizing data from 7 academic medical centers, we performed a retrospective, observational study of 5296 adult liver transplant recipients (18-80 years old) between 2000 and 2017 to identify the rate of ICA, associated risk factors, and outcomes.

RESULTS

ICA occurred in 196 cases (3.7% 95% confidence interval [CI], 3.2-4.2) and mortality occurred in 62 patients (1.2%). The intraoperative mortality rate was 31.6% in patients who experienced ICA. In a multivariable generalized linear mixed model, ICA was associated with body mass index (BMI) <20 (odds ratio [OR]: 2.04, 95% CI, 1.05-3.98; P = .0386), BMI ≥40 (2.16 [1.12-4.19]; P = .022), Model for End-Stage Liver Disease (MELD) score: (MELD 30-39: 1.75 [1.09-2.79], P = .02; MELD ≥40: 2.73 [1.53-4.85], P = .001), postreperfusion syndrome (PRS) (3.83 [2.75-5.34], P < .001), living donors (2.13 [1.16-3.89], P = .014), and reoperation (1.87 [1.13-3.11], P = .015). Overall 30-day and 1-year mortality were 4.18% and 11.0%, respectively. After ICA, 30-day and 1-year mortality were 43.9% and 52%, respectively, compared to 2.6% and 9.3% without ICA.

CONCLUSIONS

We established a 3.7% incidence of ICA and a 1.2% incidence of intraoperative mortality in liver transplantation and confirmed previously identified risk factors for ICA including BMI, MELD score, PRS, and reoperation and identified new risk factors including living donor and length of surgery in this multicenter retrospective cohort. ICA, while rare, is associated with high intraoperative mortality, and future research must focus on therapy to reduce the incidence of ICA.

A Case of Cardiac Arrest during C1 Laminectomy for Irreducible Atlantoaxial Subluxation

We report a case of cardiac arrest, which occurred during C1 laminectomy for irreducible atlantoaxial subluxation, with return of spontaneous circulation (ROSC) upon interruption of the laminectomy. A 60-year-old woman with rheumatoid arthritis presented with neck pain, bilateral finger numbness, and bladder-rectal disturbance. Simple radiograph images showed that the atlantodental interval (ADI) was enlarged to 8 mm, and magnetic resonance imaging revealed severe spinal stenosis at C1. She was diagnosed with cervical spondylotic myelopathy due to atlantoaxial subluxation. Cardiac arrest occurred twice during the C1 laminectomy and occipito-cervical fusion (Occ-C3), and ROSC occurred without any treatment. There was no postoperative worsening of neurological symptoms, and the improvement of sensory and motor palsy was favorable. The pathogenic mechanism was presumed to be trigeminocardiac reflex. Cardiac arrest during upper cervical spine surgery is an important intraoperative complication of which operators should be made aware.

Multimorbidity and Critical Care Neurosurgery: Minimizing Major Perioperative Cardiopulmonary Complications

With increasing prevalence of chronic diseases, multimorbid patients have become commonplace in the neurosurgical intensive care unit (neuro-ICU), offering unique management challenges. By reducing physiological reserve and interacting with one another, chronic comorbidities pose a greatly enhanced risk of major postoperative medical complications, especially cardiopulmonary complications, which ultimately exert a negative impact on neurosurgical outcomes. These premises underscore the importance of perioperative optimization, in turn requiring a thorough preoperative risk stratification, a basic understanding of a multimorbid patient’s deranged physiology and a proper appreciation of the potential of surgery, anesthesia and neurocritical care interventions to exacerbate comorbid pathophysiologies. This knowledge enables neurosurgeons, neuroanesthesiologists and neurointensivists to function with a heightened level of vigilance in the care of these high-risk patients and can inform the perioperative neuro-ICU management with individualized strategies able to minimize the risk of untoward outcomes. This review highlights potential pitfalls in the intra- and postoperative neuro-ICU period, describes common preoperative risk stratification tools and discusses tailored perioperative ICU management strategies in multimorbid neurosurgical patients, with a special focus on approaches geared toward the minimization of postoperative cardiopulmonary complications and unplanned reintubation.

Hemodynamically significant cardiac arrhythmias during general anesthesia for spine surgery: A case series and literature review

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Although multiple factors have been implicated, our case series highlights SSEP stimulation as a common etiology of arrhythmia.

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Significant bradycardia and CA during spine surgery does not always require termination of the surgical procedure.

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Decision making should be undertaken in each case individually based on patient condition and circumstances of each event.

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Surgeons and anesthesiologists should be aware of and prepared to treat significant cardiac arrhythmias during spine surgery even in otherwise healthy patients without known risk factors.

Background context

Hemodynamically significant bradycardia and cardiac arrest (CA) are rare under general anesthesia (GA) for spine surgery. Although patient risks are well defined, emerging data implicate surgical, anesthetic and neurologic factors which should be considered in the immediate management and decision to continue or terminate surgery.

Purpose

To characterize causes and contributors to significant arrhythmias during spine surgery. We also provide an updated literature review to inform spine care teams and aid in the management of intraoperative bradycardia and CA.

Study design

Case series and literature review

Patient sample

Six patients who underwent spine surgery from 03/2016 to 01/2020 at a single institution and developed unexpected hemodynamically significant arrhythmia

Outcome measures

Our primary outcome was to identify potential risk factors of interest for significant arrhythmia during spine surgery.

Methods

Medical records of patients who underwent spine surgery from 03/2016 to 01/2020 at a single institution and developed unexpected hemodynamically significant arrhythmia during spine surgery were identified from a departmental Quality Assurance Database. We evaluated the presence/absence of patient, surgical, anesthetic and neurologic risk factors and estimated the most likely etiology of the event, immediate and subsequent management, whether surgery was postponed or continued and outcomes.

Results

We found a temporal relationship of bradyarrhythmia and CA after somatosensory evoked potential (SSEP) stimulation in 4/6 cases and pharmacy/polypharmacy in 2/6. Surgery was completed in 4/6 patients, and terminated in 2/6 (subsequently completed in both). We found no adverse outcomes in any patients. Our literature review predominately identified case reports for guidance to support decision making. New literaure suggests peripheral nerve blocks and opioid-sparing anesthetic agents should also be considered.

Conclusions

Significant bradycardia and CA during spine surgery does not always require termination of the surgical procedure. Decision making should be undertaken in each case individually, with an updated awareness of potential causes. The study also suggests the need for large prospective studies to adequately assess incidence, risk factors and outcomes.

Transesophageal echocardiography (TEE) in the detection of intraoperative cardiac arrest: A case report

RATIONALE

Point-of-care ultrasound is widely used in patients with cardiac arrest, allowing for diagnosing, monitoring, and prognostication as well as assessing the effectiveness of the chest compressions. However, the detection of intraoperative cardiac arrest by Point-of-care ultrasound was rarely reported.

PATIENT CONCERNS

A 21-year-old male with Marfan syndrome which manifested Valsalva sinus aneurysms was admitted for aortic valve replacement. After endotracheal intubation, TEE transducer was inserted to evaluate the cardiac structure and function with different views. Severe aortic valve regurgitation was observed in the mid-esophageal aortic valve long and short axis view.

DIAGNOSIS

TEE showed that cardiac contraction was nearly stopped, the spontaneous echo contrast was obvious in the left ventricular and hardly any blood was pumped out from the heart despite the ECG showing normal sinus rhythm with HR 61 beats/min. Meanwhile, the IBP was dropped to 50/30 mm Hg.

INTERVENTIONS

Chest compressions were started immediately and epinephrine 100 μg was given intravenously. After 30 times of chest compressions, TEE showed that cardiac contractility increased and the stroke volume was improved in the TG SAX view.

OUTCOMES

The patient was discharged 18 days later in a stable condition.

LESSONS

Continuous echocardiography monitoring may be of particular value in forewarning and detecting cardiac arrest in high-risk patients.

Pharmacists in Critical Care

The beginnings of caring for critically ill patients date back to Florence Nightingale's work during the Crimean War in 1854, but the subspecialty of critical care medicine is relatively young. The first US multidisciplinary intensive care unit (ICU) was established in 1958, and the American Board of Medical Subspecialties first recognized the subspecialty of critical care medicine in 1986. Critical care pharmacy services began around the 1970s, growing in the intervening 40 years to become one of the largest practice areas for clinical pharmacists, with its own section in the SCCM, the largest international professional organization in the field. During the next decade, pharmacy services expanded to various ICU settings (both adult and pediatric), the operating room, and the emergency department. In these settings, pharmacists established clinical practices consisting of therapeutic drug monitoring, nutrition support, and participation in patient care rounds. Pharmacists also developed efficient and safe drug delivery systems with the evolution of critical care pharmacy satellites and other innovative programs. In the 1980s, critical care pharmacists designed specialized training programs and increased participation in critical care organizations. The number of critical care residencies and fellowships doubled between the early 1980s and the late 1990s. Standards for critical care residency were developed, and directories of residencies and fellowships were published. In 1989, the Clinical Pharmacy and Pharmacology Section was formed within the Society of Critical Care Medicine, the largest international, multidisciplinary, multispecialty critical care organization. This recognition acknowledged that pharmacists are necessary and valuable members of the physician-led multidisciplinary team. The Society of Critical Care Medicine Guidelines for Critical Care Services and Personnel deem that pharmacists are essential for the delivery of quality care to critically ill patients. These guidelines recommend that a pharmacist monitor drug regimen for dosing, adverse reactions, drug-drug interactions, and cost optimization for all hospitals providing critical care services. The guidelines also advocate that a specialized, decentralized pharmacist provide expertise in nutrition support, cardiorespiratory resuscitation, and clinical research in academic medical centers providing comprehensive critical care.

Reporting Methodology of Neurosurgical Studies Utilizing the American College of Surgeons-National Surgical Quality Improvement Program Database: A Systematic Review and Critical Appraisal

BACKGROUND

Use of large databases such as the American College of Surgeons-National Surgical Quality Improvement Program (ACS-NSQIP) has become increasingly common in neurosurgical research.

OBJECTIVE

To perform a critical appraisal and evaluation of the methodological reporting for studies in neurosurgical literature that utilize the ACS-NSQIP database.

METHODS

We queried Ovid MEDLINE, EMBASE, and PubMed databases for all neurosurgical studies utilizing the ACS-NSQIP. We assessed each study according to number of criteria fulfilled with respect to Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) Statement, REporting of studies Conducted using Observational Routinely-collected Health Data (RECORD) Statement, and Journal of American Medical Association–Surgical Section (JAMA-Surgery) Checklist. A separate analysis was conducted among papers published in core and noncore journals in neurosurgery according to Bradford's law.

RESULTS

A total of 117 studies were included. Median (interquartile range [IQR]) scores for number of fulfilled criteria for STROBE Statement, RECORD Statement, and JAMA-Surgery Checklist were 20 (IQR:19-21), 9 (IQR:8-9), and 6 (IQR:5-6), respectively. For STROBE Statement, RECORD Statement, and JAMA-Surgery Checklist, item 9 (potential sources of bias), item 13 (supplemental information), and item 9 (missing data/sensitivity analysis) had the highest number of studies with no fulfillment among all studies (56, 68, 50%), respectively. When comparing core journals vs noncore journals, no significant difference was found (STROBE, P = .94; RECORD, P = .24; JAMA-Surgery checklist, P = .60).

CONCLUSION

While we observed an overall satisfactory reporting of methodology, most studies lacked mention of potential sources of bias, data cleaning methods, supplemental information, and external validity. Given the pervasive role of national databases and registries for research and health care policy, the surgical community needs to ensure the credibility and quality of such studies that ultimately aim to improve the value of surgical care delivery to patients.

Neuroanesthesiology Update

We provide a synopsis of innovative research, recurring themes, and novel experimental findings pertinent to the care of neurosurgical patients and critically ill patients with neurological diseases. We cover the following broad topics: general neurosurgery, spine surgery, stroke, traumatic brain injury, monitoring, and anesthetic neurotoxicity.

Cardiac Arrest During Spine Surgery in the Prone Position: Case Report and Review of the Literature

OBJECTIVE

Intraoperative cardiac arrest (CA) is usually attributable to pre-existing disease or intraoperative complications. In rare cases, intraoperative stress can demask certain genetic diseases, such as catecholaminergic polymorphic ventricular tachycardia (CPVT). It is essential that neurosurgeons be aware of the etiologies, risk factors, and initial management of CA during surgery with the patient in the prone position.

METHODS

We present a case of CA directly after spinal fusion for lumbar spondylolisthesis and review the literature on cardiac arrests during spinal neurosurgery in the prone position. We focus on etiologies of CA in patients with structurally normal hearts.

RESULTS

After resuscitation, a 53-years-old female patient achieved return of spontaneous circulation after 17 minutes, without any neurologic deficits and with substantial improvement of functional disability and pain scores. Extensive imaging, stress testing, and genetic screening ruled out common etiologies of CA. In this patient with a structurally normal heart, CPVT was established as the most likely cause. We identified 18 additional cases of CA associated with spinal neurosurgery in the prone position. Most cases occurred during deformity or fusion procedures. Commonly reported etiologies of CA were air embolism, hypovolemia, and dural traction leading to vasovagal response. In patients with structurally normal hearts, inherited arrhythmia syndromes including CPVT, Brugada syndrome, and long QT syndrome should be included in the differential diagnosis and specifically included in testing.

CONCLUSIONS

Although intraoperative CA is rare during spine surgery, neurosurgeons should be aware of the etiologies and the specific difficulties in the management associated with the prone position.