Epidural hematoma complicating high thoracic epidural catheter placement intended for cardiac surgery

Epidural Catheterization in Cardiac Surgery: A Systematic Review and Risk Assessment of Epidural Hematoma

ABSTRACT

The potential benefits of epidural anesthesia on mortality, atrial fibrillation, and pulmonary complications must be weighed against the risk of epidural hematoma associated with intraoperative heparinization. This study aims to provide an updated assessment of the clinical risks of epidural anesthesia in cardiac surgery, focusing on the occurrence of epidural hematomas and subsequent paralysis. A systematic search of Embase, Medline, Ovid Central, Web of Science, and PubMed was conducted to identify relevant publications between 1966 and 2022. Two independent reviewers assessed the eligibility of the retrieved manuscripts. Studies reporting adult patients undergoing cardiac surgery with epidural catheterization were included. The incidence of hematomas was calculated by dividing the number of hematomas by the total number of patients in the included studies. Risk calculations utilized various denominators based on the rigor of trial designs, and the risks of hematoma and paralysis were compared to other commonly encountered risks. The analysis included a total of 33,089 patients who underwent cardiac surgery with epidural catheterization. No epidural hematomas were reported across all published RCTs, prospective, and retrospective trials. Four case reports associated epidural hematoma with epidural catheterization and perioperative heparinization. The risks of epidural hematoma and subsequent paralysis were estimated at 1:7643 (95% CI 1:3860 to 380,916) and 1:10,190 (95% CI 1:4781 to 0:1), respectively. The risk of hematoma is similar to the non-obstetric population (1:5405; 95% CI 1:4784 to 6134). The risk of hematoma in cardiac surgery patients receiving epidural anesthesia is therefore similar to that observed in some other surgical non-obstetric populations commonly exposed to epidural catheterization.

Prophylactic Low-Molecular-Weight Heparin Versus Unfractionated Heparin in Spine Surgery (PLUSS): A Pilot Matched Cohort Study

BACKGROUND

Despite a proven superior efficacy of prophylactic low-molecular-weight heparin (LMWH) over unfractionated heparin (UFH) in the majority of surgical specialties, chemoprophylactic techniques after spine surgery have not been established because of the fear of epidural hematomas with LMWH.

OBJECTIVE

To determine the efficacy of LMWH vs UFH in the prevention of venous thromboembolism (VTE) events, balanced against the risk of epidural hematoma.

METHODS

This is the first matched cohort design that directly compares prophylactic LMWH to UFH after spine surgery for degenerative/deformity pathologies at a tertiary academic center. Prospectively collected patients receiving prophylactic LMWH and a historical cohort of patients receiving prophylactic UFH (prior to 2017) were matched in 1:1 ratio based on age ±5 yr, American Society of Anesthesiologists classification, location in the spinal column, and type of surgery.

RESULTS

Of 562 patients, VTE events equaled 1.4% (n = 8): 1.4% (n = 4) with LMWH was exactly equal to 1.4% (n = 4) with UFH. Epidural hematomas reached 0.8% (n = 5): 1.4% (n = 4) with UFH vs 0.3% (n = 1) with the LMWH (P = .178). Utilizing adjusted odds ratio (ORadj), the type of chemoprophylaxis after spine surgery failed to predict VTE events. Similarly, the chemoprophylactic technique failed to predict epidural hematoma in the multivariable regression analysis, although UFH trended toward a higher complication rate (ORadj = 3.15 [0.48-20.35], P = .227).

CONCLUSION

Chemoprophylactic patterns failed to predict VTE. Although no differences in epidural hematoma rates were detected, our analysis does highlight a trend toward a safer profile with LMWH vs UFH. LMWH may be a safe alternative to UFH in spine surgery.

Perioperative Spinal Cord Ischemia After Cardiac Surgery Not Involving the Aorta: A Review of the Literature

Spinal cord ischemia (SCI) associated with aortic surgery is well-described; however, SCI after cardiac surgery not involving the aorta is an unusual and underappreciated phenomenon. The authors reviewed the literature and found 54 case reports of perioperative spinal cord ischemia in nonaortic surgery. The severity of its implications is evidenced by the fact that 14 patients died, 22 had no recovery, and seven had only partial recovery. Various types of cardiac surgery have reported this complication including coronary artery bypass grafting (CABG), off-pump CABG, valve surgeries, combination valve and CABG surgeries, and transcatheter aortic valve procedures. Patient comorbidities, such as high blood pressure, hypercholesterolemia, diabetes, and peripheral vascular disease, also may play a role in the development of this adverse outcome. The authors review the literature to define further possible mechanisms, surgical techniques, and patient factors that could contribute to the risk of perioperative SCI after cardiac surgery.

Neuraxial blocks and spinal haematoma: Review of 166 case reports published 1994–2015. Part 1: Demographics and risk-factors

Background

Bleeding into the vertebral canal causing a spinal haematoma (SH) is a rare but serious complication to central neuraxial blocks (CNB). Of all serious complications to CNBs such as meningitis, abscess, cardiovascular collapse, and nerve injury, neurological injury associated with SH has the worst prognosis for permanent harm. Around the turn of the millennium, the first guidelines were published that aimed to reduce the risk of this complication. These guidelines are based on known risk factors for SH, rather than evidence from randomised, controlled trials (RCTs). RCTs, and therefore meta-analysis of RCTs, are not appropriate for identifying rare events. Analysing published case reports of rare complications may at least reveal risk factors and can thereby improve management of CNBs. The aims of the present review were to analyse case reports of SH after CNBs published between 1994 and 2015, and compare these with previous reviews of case reports.

Methods

MEDLINE and EMBASE were used for identifying case reports published in English, German, or Scandinavian languages, using appropriate search terms. Reference lists were also scrutinised for case reports. Twenty different variables from each case were specifically searched for and filled out on an Excel spreadsheet, and incidences were calculated using the number of informative reports as denominator for each variable.

Results

Altogether 166 case reports on spinal haematoma after CNB published during the years between 1994 and 2015 were collected. The annual number of case reports published during this period almost trebled compared with the two preceding decades. This trend continued even after the first guidelines on safe practice of CNBs appeared around year 2000, although more cases complied with such guidelines during the second half of the observation period (2005–2015) than during the first half. Three types of risk factors dominated:(1)Patient-related risk factors such as haemostatic and spinal disorders, (2) CNB-procedure-related risks such as complicated block, (3) Drug-related risks, i.e. medication with antihaemostatic drugs.

Conclusions and implications

The annual number of published cases of spinal haematoma after central neuraxial blocks increased during the last two decades (1994–2015) compared to previous decades. Case reports on elderly women account for this increase.Antihaemostatic drugs, heparins in particular, are still major risk factors for developing post-CNB spinal bleedings. Other risk factors are haemostatic and spinal disorders and complicated blocks, especially “bloody taps”, whereas multiple attempts do not seem to increase the risk of bleeding. In a large number of cases, no risk factor was reported. Guidelines issued around the turn of the century do not seem to have affected the number of published reports. In most cases, guidelines were followed, especially during the second half of the study period. Thus, although guidelines reduce the risk of a post-CNB spinal haematoma, and should be strictly adhered to in every single case, they are no guarantee against such bleedings to occur.

Benefits and risks of epidural analgesia in cardiac surgery

BACKGROUND

Epidurals provide excellent analgesia for cardiac surgery and may reduce complications. However, their use has been tempered because of concern of the rare, but serious complication of epidural haematoma. The aim of this meta-analysis was to assess the effect of epidural on survival and the risk estimate of epidural haematoma.

METHODS

A systematic review of the literature (Pubmed, Embase, Scopus and the Cochrane Register) and a meta-analysis of the available randomized and case-matched studies were performed to estimate the effect on survival. An international, directed and viral anonymous survey was performed to identify the incidence of haematomas with a corresponding estimate of the number of epidurals performed.

RESULTS

Of 66 randomized and case-matched studies, 57 trials including 6383 patients reported the incidence of all-cause mortality at the longest follow up available, with a significant reduction with epidurals (59/3123 [1.9%] vs 108/3260 [3.3%] in the control arm, RR 0.65 [95% CI 0.48-0.86], P=0.003, NNT=70). No epidural haematoma was reported in these 66 trials (3320 epidurals). All other literature revealed nine haematomas in 13,100 patients. Through the anonymous, web-based, viral, international survey, we identified 16 further, non-published, epidural haematomas from 72,400 positioned epidurals. Therefore, a total of 25 haematomas have been identified from an estimate of 88,820 positioned epidurals, producing an estimated risk of 1:3552 (95% CI 1:2552-1:5841).

CONCLUSIONS

The use of epidural analgesia in cardiac surgery is associated with a reduction in mortality (NNT=70), and with an estimated risk of epidural haematoma of 1:3552.

Managing anticoagulated patients during neuraxial anaesthesia

The widespread use of central neuraxial block (CNB) and the prevalence of anticoagulation for different indications have led to an inevitable overlap between the two. The most serious complication of CNB in anticoagulated patients is the risk of spinal/epidural haematoma. Performing CNB in these patients is a complex decision that should take into account the twin risks of bleeding and venous/arterial thrombosis if anticoagulation therapies were to be stopped. Various guidelines have been issued to achieve normal haemostasis and thus allow safe administration of CNB. However, the evidence base for many such recommendations is weak, relying mainly on case reports, small studies and pharmacokinetics of the drugs. Given these limitations it is crucial to fully assess individual risk factors and understand anticoagulant pharmacokinetics in order to appropriately set time intervals for catheter insertion/removal. This paper will review traditional and newer anticoagulation/antiplatelet therapies with a view to improving the management of anticoagulated patients undergoing CNB.

Epidural analgesia improves outcome in cardiac surgery: a meta-analysis of randomized controlled trials

OBJECTIVE

The authors conducted a review of randomized studies to determine whether there were any advantages for clinically relevant outcomes by adding epidural analgesia in patients undergoing cardiac surgery under general anesthesia.

DESIGN

Meta-analysis.

SETTING

Hospitals.

PARTICIPANTS

A total of 2366 patients from 33 randomized trials.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

DATA SOURCES AND STUDY SELECTION

PubMed, BioMedCentral, CENTRAL, EMBASE, Cochrane Central Register of Controlled Trials, and conference proceedings were searched (updated January 2008) for randomized trials that compared general anesthesia with an anesthetic plan including general anesthesia and epidural analgesia in cardiac surgery. Two independent reviewers appraised study quality, with divergences resolved by consensus. Overall analysis showed that epidural analgesia reduced the risk of the composite endpoint mortality and myocardial infarction (30/1125 [2.7%] in the epidural group v 64/1241 [5.2%] in the control arm, odds ratio [OR] = 0.61 [0.40-0.95], p = 0.03 number needed to treat [NNT] = 40), the risk of acute renal failure (35/590 [5.9%] in the epidural group v 54/618 [8.7%] in the control arm, OR = 0.56 [0.34-0.93], p = 0.02, NNT = 36), and the time of mechanical ventilation (weighted mean differences = -2.48 hours [-2.64, -2.32], p < 0.001).

CONCLUSIONS

This analysis suggested that epidural analgesia on top of general anesthesia reduced the incidence of perioperative acute renal failure, the time on mechanical ventilation, and the composite endpoint of mortality and myocardial infarction in patients undergoing cardiac surgery.

Epidural analgesia in cardiac surgery: an updated risk assessment

INTRODUCTION

The use of epidural anesthesia carries risks that have been known for 50 years. The debate about the use of locoregional technique in cardiac anesthesia continues. The objective of this report is to estimate the risks and their variability of a catheter-related epidural hematoma in cardiac surgery patients and to compare it with other anesthetic and medical procedures.

METHODS

Case series reporting the use of epidural anesthesia in cardiac surgery were researched through Medline. Additional references were retrieved from the bibliography of published articles and from the internet. Risks of complications in other anesthetic and medical activity were retrieved from recent reviews.

RESULTS

Based on the present evidence, the risk of epidural hematoma in cardiac surgery is 1:12,000 (95% CI of 1:2100 to 1:68,000), which is comparable to the risk in the nonobstetrical population of 1:10,000 (95% CI 1:6700 to 1:14,900). The risk of epidural hematoma is comparable to the risk of receiving a wrong blood product or the yearly risk of having a fatal road accident in Western countries.

CONCLUSIONS

The risk of a hematoma after epidural in cardiac surgery is comparable to other nonobstetrical surgical procedures. Its routine application in a controlled setting should be encouraged.

New approaches and old controversies to postoperative pain control following cardiac surgery

OBJECTIVE

To evaluate the effect of postoperative pain control in cardiac surgical patients on morbidity, mortality and other outcome measures.

BACKGROUND

New approaches in pain control have been introduced over the past decade. The impact of these interventions, either alone or in combination, on perioperative outcome was evaluated in cardiac surgical patients.

METHODS

We searched Medline for the period of 1980 to the present using the key terms analgesics, opioid, non-steroidal anti-inflammatory drugs, cardiac surgery, regional analgesia, spinal, epidural, fast-track cardiac anaesthesia, fast-track cardiac surgery, myocardial ischaemia, myocardial infarction, postoperative care, accelerated care programmes, postoperative complications, and we examined and discussed the articles that were identified to be included in this review.

RESULTS

Pain management in cardiac surgery is becoming more important with the establishment of minimally invasive direct coronary artery bypass surgery and fast-track management of conventional cardiac surgery patients. Advances have been made in this area and encompass specific techniques, such as central neuraxial blockade or selective nerve blocks, and drugs (opioids, sedative-hypnotics and non-steroidal anti-inflammatory drugs). Ideally, these therapies provide not only patient comfort but also mitigate untoward cardiovascular responses, pulmonary responses, and other inflammatory and secondary sympathetic responses. The introduction of these newer approaches to perioperative care has reduced morbidity, but not mortality, in cardiac surgical patients.

CONCLUSIONS

Understanding perioperative pathophysiology and implementation of care regimes to reduce the stress of cardiac surgery, will continue to accelerate rehabilitation associated with decreased hospitalization and increased satisfaction and safety after discharge. Reorganization of the perioperative team (anaesthesiologists, surgeons, nurses and physical therapists) will be essential to achieve successful fast-track cardiac surgical programmes. Developments and improvements of multimodal interventions within the context of 'fast-track' cardiac surgery programmes represents the major challenge for the medical professionals working to achieve a 'pain and risk free' perioperative course.