0
Communications to the Editor |

Safety of Neuraxial Anesthesia in Patients Receiving Perioperative Low-Molecular-Weight Heparin for Thromboprophylaxis FREE TO VIEW

Juan V. Llau, MD
Author and Funding Information

Hospital Clínico Universitario Valencia, Spain

Correspondence to: Juan V. Llau, MD, Department of Anesthesiology and Post-Surgical Intensive Care, Hospital Clinico Universitario, Av Blasco Ibáñez 17, Valencia, Spain 46006; e-mail: jvllau@teleline.es



Chest. 1999;116(6):1843-1844. doi:10.1378/chest.116.6.1843-b
Text Size: A A A
Published online

To the Editor:

I read with interest the recent article by Aguilar and Goldhaber (May 1999)1 on the subject of low-molecular-weight heparins (LMWHs). LMWHs are widely employed in the perioperative period for the prophylaxis of deep venous thrombosis (DVT) and are considered to be safe and effective.

However, the decision to use LMWHs may not be made without some trepidation. When deciding to perform neuraxial blockade on a patient who is already receiving an LMWH, the anesthesiologist may believe that the benefits of regional anesthesia for this specific patient are greater than the risk of developing intraspinal bleeding, even assuming that the patient has had an alteration in hemostasis.

So, what should be done to minimize the very low risk of developing neurologic injury while maintaining the antithrombotic effectiveness of LMWHs? I would like to propose a checklist (Table 1 ) and to summarize some recommendations to improve the safety of neuraxial anesthesia in patients who have received or will receive thromboprophylaxis with LMWHs27:

1. Postsurgical administration of LMWH. Except in some specific patients (very high-risk patients or in those having surgery for a hip fracture), it is possible to perform thromboprophylaxis with LMWH starting 10 to 12 h after surgery without a loss of effectiveness. This would be the best choice for improving the safety of neuraxial anesthesia.

2. Preoperative LMWH. If LMWH has to be administered before surgery, spinal anesthesia should be delayed at least 10 to 12 h after the last LMWH dose, with the next dose being given 2 to 4 h after that initial dose.

3. LMWH dosing. It has to be the minimal effective dose. Sometimes an LMWH dose can be adjusted for body weight to avoid overdosing. Furthermore, it is of primary importance to know the differences in drug regimens between Europe and the United States: the current American dosing practice is to administer 50% more than is called for by the current European practice (eg, enoxaparin, 30 mg twice daily vs 40 mg once daily, respectively).

4. Continuous catheter technique. There is no problem in using it if the LMWH is started postoperatively or at least 12 h before. It is not safe to place a catheter for postoperative analgesia when LMWH has been administered < 10 to 12 h before. However, frequent monitoring for signs of neurologic impairment is needed in all cases. The removal of this catheter has to be delayed until 10 to 12 h after the last dose of LMWH (ideally, 24 h).

5. Remaining questions. If the decision is made to perform neuraxial anesthesia despite the prior administration of LMWH, the following procedures are recommended: • Do not use the continuous-catheter technique. A single-dose spinal anesthesia may be the safest regional anesthesia technique. • Use small-gauge needles. • Use short-acting anesthetics. • Use the midline approach. • Observe the patient closely in the early postoperative period for any sign of cord compression, and if signs are noticed, obtain immediate radiographic confirmation and treat the patient without delay.

In conclusion, the decision to perform regional anesthesia in patients receiving LMWH for prophylaxis of DVT can be made safely in selected patients. Some anesthesia and thromboprophylaxis guidelines should be followed to minimize the risk of spinal bleeding. However, the final decision should be made by the clinician after estimating the benefits and risks of the simultaneous use of LMWH and regional anesthesia.

Table Graphic Jump Location
Table 1. Central Nerve Block-LMWH Administration Safety Checklist*
* 

Yes = central nerve block is safe; No = need to estimate benefits and risks to perform central nerve block.

References

Aguilar, D, Goldhaber, SZ (1999) Clinical uses of low-molecular-weight heparins.Chest115,1418-1423. [CrossRef]
 
Horlocker, TT, Heit, JA Low molecular weight heparin: biochemistry, pharmacology, perioperative prophylaxis regimens, and guidelines for regional anesthetic management.Anesth Analg1997;85,874-885. [CrossRef]
 
Checketts, MR, Wildsmith, JAW Central nerve block and thromboprophylaxis: is there a problem [editorial]?Br J Anaesth1999;82,164-167. [CrossRef]
 
Horlocker, TT, Wedel, DJ Anticoagulants, antiplatelets therapy and neuraxis blockade.Anesthesiol Clin North Am1992;10,1-11
 
Bullingham, A, Strunin, L Prevention of postoperative venous thromboembolism.Br J Anaesth1995;75,622-630. [CrossRef]
 
Llau, JV, Hoyas, L, Ezpeleta, J, et al Heparinas de bajo peso molecular: implicaciones en anestesia y reanimación.Rev Esp Anestesiol Reanim1997;44,70-78
 
Weitz, JI Low-molecular-weight heparins.N Engl J Med1997;337,688-698. [CrossRef]
 

Figures

Tables

Table Graphic Jump Location
Table 1. Central Nerve Block-LMWH Administration Safety Checklist*
* 

Yes = central nerve block is safe; No = need to estimate benefits and risks to perform central nerve block.

References

Aguilar, D, Goldhaber, SZ (1999) Clinical uses of low-molecular-weight heparins.Chest115,1418-1423. [CrossRef]
 
Horlocker, TT, Heit, JA Low molecular weight heparin: biochemistry, pharmacology, perioperative prophylaxis regimens, and guidelines for regional anesthetic management.Anesth Analg1997;85,874-885. [CrossRef]
 
Checketts, MR, Wildsmith, JAW Central nerve block and thromboprophylaxis: is there a problem [editorial]?Br J Anaesth1999;82,164-167. [CrossRef]
 
Horlocker, TT, Wedel, DJ Anticoagulants, antiplatelets therapy and neuraxis blockade.Anesthesiol Clin North Am1992;10,1-11
 
Bullingham, A, Strunin, L Prevention of postoperative venous thromboembolism.Br J Anaesth1995;75,622-630. [CrossRef]
 
Llau, JV, Hoyas, L, Ezpeleta, J, et al Heparinas de bajo peso molecular: implicaciones en anestesia y reanimación.Rev Esp Anestesiol Reanim1997;44,70-78
 
Weitz, JI Low-molecular-weight heparins.N Engl J Med1997;337,688-698. [CrossRef]
 
NOTE:
Citing articles are presented as examples only. In non-demo SCM6 implementation, integration with CrossRef’s "Cited By" API will populate this tab (http://www.crossref.org/citedby.html).

Some tools below are only available to our subscribers or users with an online account.

Related Content

Customize your page view by dragging & repositioning the boxes below.

  • CHEST Journal
    Print ISSN: 0012-3692
    Online ISSN: 1931-3543