Coagulation abnormalities and obstetric anaesthesia

Evaluating hemostatic thresholds for neuraxial anesthesia in adults with hemorrhagic disorders and tendencies: A scoping review

Neuraxial anesthesia can be complicated by spinal or epidural hematoma and may result in permanent neurologic injury. There is a paucity of literature characterizing this serious complication in patients with congenital and acquired hemorrhagic disorders or tendencies. The objective of this scoping review was to describe the hemostatic laboratory parameters where neuraxial anesthesia has been administered with and without spinal and epidural hematoma in patients with preexisting hemorrhagic disorders and tendencies, including immune thrombocytopenia, gestational thrombocytopenia, thrombocytopenia associated with hypertensive disorders of pregnancy, platelet function disorders, von Willebrand disease, coagulation factor deficiencies, and fibrinogen disorders. A systematic search of Ovid MEDLINE, CINAHL, Embase, Scopus, and Web of Science was performed. Two authors independently reviewed all titles, abstracts, and full texts to determine study eligibility and extract data. Qualitative synthesis of 91 studies revealed significant gaps in our understanding of the risk of spinal and epidural hematoma in patients with hemorrhagic disorders and tendencies, including few studies of males and in nonobstetric settings. Most reviewed articles were small, retrospective studies at high risk for potential bias. With such low-quality data, we were unable to provide any true estimates of the risk of spinal or epidural hematoma for these patients, nor could we attribute any specific hemostatic or laboratory values to increased risk of hematoma. There is a need both for larger and more rigorously designed and reported studies on this subject and for structured, comprehensive recommendations for safe administration and removal of neuraxial anesthesia in patients with hemorrhagic disorders and tendencies.

[SBA 2020: Regional anesthesia guideline for using anticoagulants update]

The development of protocols to prevent perioperative Venous Thromboembolism (VTE) and the introduction of increasingly potent antithrombotic drugs have resulted in concerns of increased risk of neuraxial bleeding. Since the Brazilian Society of Anesthesiology (SBA) 2014 guideline, new oral anticoagulant drugs were approved by international regulating agencies, and by ANVISA. Societies and organizations that try to approach concerns through guidelines have presented conflicting perioperative management recommendations. As a response to these issues and to the need for a more rational approach, managements were updated in the present narrative revision, and guideline statements made. They were projected to encourage safe and quality patient care, but cannot assure specific results. Like any clinical guide recommendation, they are subject to review as knowledge grows, on specific complications, for example. The objective was to assess safety aspects of regional analgesia and anesthesia in patients using antithrombotic drugs, such as: possible technique-associated complications; spinal hematoma-associated risk factors, prevention strategies, diagnosis and treatment; safe interval for discontinuing and reinitiating medication after regional blockade.

Anesthesia implications of coagulation and anticoagulation during pregnancy

Coagulation is an organized and well-orchestrated process that depends on the intrinsic balance between procoagulants, anticoagulants, and fibrinolytic systems. During pregnancy, this balance is affected in various ways and becomes more critical due to the physiologic changes and obligate hemorrhage after delivery. In some instances, this equilibrium will be disrupted. In this article, we describe the anesthetic implications of bleeding disorders, thrombophilias, and anticoagulation for the safe management of the parturient, with an emphasis on how this impacts decision-making by the anesthesiologist.

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.

Survey of epidural analgesia management in general intensive care units in England

BACKGROUND

The management of epidural analgesia is controversial. Many intensive care unit (ICU) patients may benefit from this form of analgesia but have one or more contraindications to its use. Sepsis, coagulopathy, insertion in a sedated, ventilated patient, and lack of consent are common problems in ICU patients. Little has been published to help guide practice in this area. I wished to establish the current practice of the management of epidural analgesia in general ICUs in England when relative or absolute contraindications occur, in order to determine the current standard of care for placement and use of epidural analgesia in ICU patients.

METHODS

A postal questionnaire survey of the management of epidural analgesia in critically ill patients was sent to the named clinical director of all (216) general ICUs in England.

RESULTS

Responses were received from 159 (75%) units: 89% of responding units use epidural analgesia but only 51(32%) have a written policy covering its use. Anesthetists or intensivists with an anesthetic background sited all epidural catheters; 68% of units would not site an epidural in a patient with positive blood cultures; but only 52% considered culture negative sepsis (systemic signs of sepsis with no organism isolated) to be a contraindication. Neither lack of consent nor the need for anticoagulation after the catheter had been sited were considered contraindications to inserting an epidural catheter by the majority of respondents. Although 71% of the units would remove an epidural catheter if a patient developed positive blood cultures after it had been sited, the majority of the ICUs did not consider culture negative sepsis and the need for anticoagulation contraindications to maintain a previously sited epidural.

CONCLUSIONS

Practice varied considerably with little consensus. Although all the respondents use epidural analgesia in critically ill patients, the indications and contraindications to epidural analgesia remain controversial, and further research is required to help define the role of epidural analgesia in this high-risk group.

Neurological complications in obstetric regional anaesthesia

Neurological complications after obstetric central neural blocks are rare events. Although central neural blockade does cause neurological complications, there must be awareness that neurological deficits may either develop spontaneously (e.g. epidural abscess/haematoma) or as a result of the labour and delivery process (maternal obstetric palsies). We have attempted to review as completely as possible the published survey and case reports in the English literature on neurological complications of obstetric regional blockade obtained from Medline spanning the period 1966 to November 1998. We also performed cross-checking of our references to find important missing articles, e.g. papers published in journals not included in Index Medicus at the time of publication, such as the International Journal of Obstetric Anesthesia. We wish to provide some insight to the incidences, pathophysiology, clinical features, investigations, treatment and prognosis of these complications. Maternal obstetric palsies and case reports of spontaneous epidural abscess/haematoma are also discussed. It is often difficult, if not impossible, to determine the exact aetiology, but unfortunately for the anaesthetists, regional blockade is usually incriminated till proven otherwise. Although we cannot eliminate the occurrence of neurological complications completely, preventive measures can still be taken to decrease their incidence (e.g. aseptic technique). There must also be regular monitoring after neural blockade for the development of neurological complications. Early diagnosis and prompt appropriate treatment will usually lead to complete resolution of the neurological deficit even in cases of epidural haematoma/abscess.

[Evaluation of hemostasis before obstetrical epidural anesthesia: a survey in 435 French obstetric departments]

OBJECTIVES

To specify by which means French anaesthesiologists evaluate the haemostasis profile of pregnant women before epidural analgesia.

STUDY DESIGN

Nationwide retrospective survey.

MATERIAL

Questionnaire sent of 847 French obstetrical units.

METHODS

Comparison of categorical qualitative parameters using a chi 2 test.

RESULTS

Answers from 435 centres, including 1,834 anaesthesiologists, performing 227 x 10(3) epidurals for 411 x 10(3) deliveries/year were obtained. A preanaesthetic clinical assessment was performed systematically in two out of three units, and blood samples for PT, aPTT and platelet count were taken in more than 90% of the centres. These laboratory examinations were often made during the 9th month of pregnancy (74%). For more than one-third of the anaesthesiologists, biological data are not essential before epidural puncture. In addition, the lower limits considered as being safe before epidural puncture were highly variable between the teams.

CONCLUSIONS

Coagulation laboratory tests are almost always ordered before epidural obstetrical analgesia in France. The rationale to perform them is not always related to pregnancy induced haemostatic changes. Therefore, this problem should be clarified by a consensus conference for both practical and economical reasons.

Lupus anticoagulant, paramyotonia congenita and pregnancy

A case report is presented of the anaesthetic management of a parturient with paramyotonia congenita and lupus anticoagulant antibodies. She had been treated with prophylactic, subcutaneous heparin and aspirin throughout her pregnancy. Epidural analgesia was provided for labour and delivery.