Use of thromboelastography to demonstrate persistent anticoagulation after stopping enoxaparin*

Pre- to postoperative coagulation profile of 307 patients undergoing oesophageal resection with epidural blockade over a 10-year period in a single hospital: implications for the risk of spinal haematoma

Background

Epidural anaesthesia and analgesia are indicated for oesophageal surgery. A rare but serious complication is spinal haematoma, which can occur on insertion, manipulation or withdrawal of catheters. Evidence and guidelines are vague regarding which tests are appropriate and how to interpret their results. We aimed to describe how routine coagulation test results change during oesophagectomy’s perioperative course.

Methods

Following ethical approval, we retrospectively identified patients who had undergone oesophagectomy between 2002 and 2012. Blood test results and details of operations, haemorrhage and complications were recorded and analysed with Excel and R. A literature search was conducted using the PubMed terms ‘epidural’ AND ‘coagulation’ AND English language. Relevant articles published in 2000 and after were included.

Results

Three hundred and seven patients received a thoracic epidural infusion with bupivacaine and morphine while 51 received an intravenous morphine infusion. Tests taken preoperatively and before the planned withdrawal of the epidural catheter demonstrated increases in all three measures: aPTT (activated partial thromboplastin time), PT-INR (prothrombin international normalised ratio) and platelet count (Plc). Postoperative thrombocytopenia was almost non-existent while aPTT or PT-INR was elevated above the reference range in 129/307 patients: aPTT was elevated in 116/307 while PT-INR was elevated in 32/307. This is too small a sample to allow meaningful estimation of risk of spinal haematoma: it may be as high as 2.3%. The literature search returned 275 articles, of which 57 were relevant. Twenty-one concerned the natural history of postoperative coagulation; 16, the incidence of and risk factors for spinal haematoma; and 5, evaluation of specific blood tests. Postoperative coagulation is characterised by thrombocytosis and transient moderately abnormal routine coagulation test results. Viscoelastic tests are not validated in the stable postoperative setting.

Conclusions

Screening for coagulopathy before removal of epidural catheters is of unclear benefit since elevated aPTT and PT-INR are usual and may not indicate hypocoagulation. A thorough clinical assessment is important. We nevertheless recommend caution when being presented with elevated routine tests of coagulation before withdrawing an epidural catheter: viscoelastic haemostatic tests may have a role in testing before withdrawal of epidural catheters but they are so far not validated. Future research should include advanced coagulation analysis as soon as a patient is unfortunate enough to have a spinal haematoma.

Electronic supplementary material

The online version of this article (10.1186/s13741-017-0070-7) contains supplementary material, which is available to authorized users.

Thromboelastographic changes during laparoscopic fundoplication

Introduction

Thromboelastography (TEG) is a technique that measures coagulation processes and surveys the properties of a viscoelastic blood clot, from its formation to lysis.

Aim

To determine the possible hypercoagulability state and the effect of antithrombotic prophylaxis on thromboelastogram results and development of venous thrombosis during laparoscopic fundoplication.

Material and methods

The study was performed on 106 patients who were randomized into two groups. The first group received low-molecular-weight heparin (LMWH) 12 h before the operation, and 6 and 30 h after it. The second group received LMWH only 1 h before the laparoscopic fundoplication. The TEG profile was collected before LMWH injection, 1 h after the introduction of the laparoscope and 15 min after the surgery was completed.

Results

There was no significant difference in thromboelastography R-time between the groups before low-molecular-weight heparin injection. In group I preoperative R-values significantly decreased 1 h after the introduction of the laparoscope, after the end of surgery and on the third postoperative day. K-time values decreased significantly on the third postoperative day compared with the results before low-molecular-weight heparin injection, and after the operation. In group II, preoperative R-values significantly decreased 1 h after the introduction of the laparoscope, and after surgery. K-time values did not change significantly during or after the laparoscopic operation.

Conclusions

Our study results demonstrated that the hypercoagulation state (according to the TEG results) was observed during and after laparoscopic fundoplication in patients when LMWH was administered 12 h before the operation together with intraoperative intermittent pneumatic compression. The optimal anticoagulation was obtained when LMWH was administered 1 h before fundoplication.

Risk factors for coagulopathy after liver resection

STUDY OBJECTIVE

To identify risk factors for coagulopathy in patients undergoing liver resection.

DESIGN

A retrospective cohort study.

SETTING

Patients who underwent liver resection at a university hospital between April 2010 and May 2011 were evaluated within seven days after surgery.

PATIENTS

One hundred forty-seven patients were assessed for eligibility. Thirty needed to be excluded because of incomplete data (23) or a preexisting coagulopathy (7).

MEASUREMENTS

Coagulopathy was defined as 1 or more of the following events: international normalized ratio ≥1.4, platelet count <80,000/μL, and partial thromboplastin time >38 seconds. Related to the time course and coagulation profile thresholds, 3 different groups could be distinguished: no coagulopathy, temporary coagulopathy, and persistent coagulopathy.

MAIN RESULTS

Seventy-seven patients (65.8%) had no coagulopathy, whereas 33 (28.2%) developed temporary coagulopathy and 7 (6%) developed persistent coagulopathy until day 7. Preoperative international normalized ratio (P = .001), postoperative peak lactate levels (P = .012), and resected liver weight (P = .005) were identified as independent predictors. Preoperative liver transaminases and transfusion volumes of red blood cells and fresh frozen plasma were significantly higher in patients with persistent coagulopathy.

CONCLUSIONS

Epidural anesthesia is feasible in patients scheduled for liver resection. Caution should be observed for patients with extended resection (≥3 segments) and increased postoperative lactate. In patients with preexisting liver disease, epidural catheters should be avoided.