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

Abstract

<jats:title>Abstract</jats:title><jats:sec id="j_j.sjpain.2016.11.008_s_006_w2aab2b8c29b1b7b1aab1c15b1Aa"><jats:title>Background</jats:title><jats:p>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.</jats:p></jats:sec><jats:sec id="j_j.sjpain.2016.11.008_s_007_w2aab2b8c29b1b7b1aab1c15b2Aa"><jats:title>Methods</jats:title><jats:p>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.</jats:p></jats:sec><jats:sec id="j_j.sjpain.2016.11.008_s_008_w2aab2b8c29b1b7b1aab1c15b3Aa"><jats:title>Results</jats:title><jats:p>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)<jats:italic>Patient-related risk</jats:italic> factors such as haemostatic and spinal disorders, (2) <jats:italic>CNB-procedure-related risks</jats:italic> such as complicated block, (3) <jats:italic>Drug-related risks</jats:italic>, i.e. medication with antihaemostatic drugs.</jats:p></jats:sec><jats:sec id="j_j.sjpain.2016.11.008_s_009_w2aab2b8c29b1b7b1aab1c15b4Aa"><jats:title> Conclusions and implications</jats:title><jats:p>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.</jats:p></jats:sec>

Reducing risk of spinal haematoma from spinal and epidural pain procedures

“…As there is no RCT-based evidence, our senior author, Michael Lagerkranser, published separately a large review on risk factors for post-CNB SH based on 166 case reports published since 1994 by searching PubMed and EMBASE [2,6]. The findings of his reports are included in the present practise advisory document.…”

“…The most serious complications are haematoma [2,6], or abscess [3]: it is a double tragedy when the patient experiences a failed epidural with no pain-relief, at the same time as having a damaged spinal cord from a haematoma or an abscess in the spinal canal.…”

“…spinal or epidural analgesia procedures, are rare but potentially tragic complications that may result in permanent paraplegia and urinary and/or rectal incontinence. The occurrence varies enormously with the presence or absence of risk factors [1,2]. Experienced clinicians from the Scandinavian Society of Anaesthesiology and Intensive Care Medicine (SSAI) published in 2010 common Nordic guidelines on how to minimise the risk of spinal haematoma (SH) from CNBs for pain relief during and after major surgery or childbirth [1].…”

“…Therefore, guidelines in this area are mainly based on knowledge of drugs that increase the risk of bleeding. There are, however, a number of other risk factors related to CNB procedures, how they are performed and monitored, and on patients' comorbidities [2].…”

“…This practise advisory is also based on more experience with antihaemostatic drugs that were new or introduced after 2010 [4]. There is new knowledge about monitoring of antihaemostatic drugs [5], and new insight in risk factors, treatment and outcome of this rare complication from a recent analysis of published case reports of SH [2,6].…”