What is a safe platelet count prior
to invasive procedures?
Evidence-Based Answer
Epidural anesthesia and central line placement can
be performed with platelet counts above 50,000/μL.
(SOR: B, based on retrospective studies.) Lumbar
puncture (LP) can be performed with platelet counts
above 20,000/μL. (SOR: C, based on a retrospective
study, case series, and expert opinion.) Additional
common invasive procedures should have platelet
counts above 50,000/μL. (SOR: C, based on expert
opinion.)
A 2009 retrospective study (n=75) assessed the safety
of epidural and other regional anesthesia in nonpreeclamptic women with thrombocytopenia (platelet
counts <100,000/μL). Regional anesthesia was given to
13 patients who had platelet counts between 50,000 and
79,000/μL and 34 patients with platelet counts between
80,000 and 100,000/μL. No patients with platelet
counts <50,000/μL received regional anesthesia. No
neurologic complications were observed. The authors
concluded that regional anesthesia is safe with platelet
counts of 50,000/μL or more.1
A retrospective study investigated complication
rates of central venous catheter placement in
76 patients with hemostasis disorders. Seven patients
with a mean platelet count of 22,000/μL developed
significant bleeding at the catheter site. All bleeding
complications occurred with insertion of subclavian
vein catheters. Bleeding resolved in 6 patients with
application of pressure and 1 patient (platelet
count=6,000/μL) required a platelet transfusion.2
LP was the focus of a 1974 case-series that
reviewed 8 adult patients who developed subdural
spinal hematomas after spinal fluid sampling.3 Five of
the 8 patients had platelet counts <20,000/μL. Based
on these findings, the authors recommended platelet
transfusion prior to LP for adult patients with platelet
counts <20,000/μL.
A retrospective review (n=956 patients; 5,223
procedures) evaluated LP complications in pediatric
patients with acute lymphocytic leukemia. A total
of 742 LPs were performed on patients with platelet
counts between 21,000 and 50,000/μL, 170 LPs with
platelet counts between 11,000 and 20,000/μL, and
29 LPs with platelet counts <10,000/μL. No serious
8
Evidence-Based Practice / November 2011
complications (neurologic, infectious, or hemorrhagic)
were encountered regardless of the platelet count
(95% CI, 0–0.07). The authors concluded children
do not require platelet transfusion prior to LP if the
platelet count is >10,000/μL.4
The British Committee for Standards in
Haematology Task Force recommends a platelet
count >50,000/μL for epidural anesthesia, insertion
of central lines, LP, or other similar procedures.5 The
American Society of Clinical Oncology’s expert opinion
recommends platelet counts of 40,000 to 50,000/μL for
the insertion of central lines and minor surgery in the
absence of associated coagulation abnormalities. For
LPs they recommend platelet counts >20,000/μL.6 The
American College of Obstetricians and Gynecologists
states that pregnant patients may be candidates for
regional anesthesia with platelet counts between
50,000 and 100,000/µL.7
Carl Hoogesteger, MD
Robert L. Gauer, MD
Womack FMR Clinic
Fort Bragg, NC
The opinions and assertions contained herein are the private views
of the authors and are not to be construed as official or as reflecting the views
of the US Army Medical Department or the US Army at large.
1.Tanaka M, Balki M, McLeod A, Carvalho JC. Rev Bras Anestesiol. 2009; 59(2):142–153.
[LOE 2b]
2.Doerfler ME, Kaufman B, Goldenberg AS. Chest. 1996; 110(1):185–188. [LOE 2b]
3.Edelson RN, Chernik NL, Posner JB. Arch Neurol. 1974; 31(2):134–137. [LOE 4]
4.Howard SC, Gajjar A, Ribeiro RC, et al. JAMA. 2000; 284(17):2222–2224. [LOE 2b]
5.British Committee for Standards in Haematology, Blood Transfusion Task Force. Br J
Haematol. 2003; 122(1):10–23. [LOE 5]
6.Schiffer CA, Anderson KC, Bennett CL, et al. J Clin Oncol. 2001; 19(5):1519–1538.
[LOE 5]
7.American College of Obstetrics and Gynecology. ACOG practice bulletin. Int J Gynaecol
Obstet. 2002; 78(3):321–335.
Is inhaled cannabis an effective treatment
for chronic neuropathic pain?
Evidence-Based Answer
When taken with standard analgesics, inhaled cannabis
relieves refractory neuropathic pain better than inhaled
placebo in short-term studies. (SOR: B, based on small
RCTs.)
A double-blinded crossover trial, using 3 different
potencies (2.5%, 6.0%, 9.4%) of tetrahydrocannabinol
(THC) and placebo cigarettes, enrolled 23 patients
with posttraumatic and postsurgical neuropathic pain