20 AJR:206, January 2016 for as long as 24 hours, necessitating an over- night stay in the hospital for a dural puncture. Dural puncture is now commonly performed as an outpatient procedure with a much short- er observation period because lengthy obser- vation was not found to significantly decrease the risk of headache [2]. The initial treatment of headache after a dural puncture is conser- vative management including increased fluid intake, acetaminophen, nonsteroidal antiin- flammatory drugs, opioids, and antiemetics [1]. Refractory headaches may require addi- tional intervention such as an epidural blood patch for treatment [3]. Most of the literature describing compli- cations of dural puncture was written by an- esthesiologists and neurologists because of their roles in obstetric anesthesia and lum- bar punctures. Thus, the existing literature on headache after dural puncture has chiefly JOURNAL CLUB: Incidence of Complications Following Fluoroscopically Guided Lumbar Punctures and Myelograms David Rodriguez 1 Barton F. Branstetter IV 1 Vikas Agarwal 1 Stacie Palfey 1 Kevin C. Ching 1 Gregory M. Bump 2 Marion A. Hughes 1 Rodriguez D, Branstetter BF IV, Agarwal V, et al. 1 Department of Radiology, University of Pittsburgh Medical Center, 200 Lothrop St, PUH Rm D132, Pittsburgh, PA 15213. Address correspondence to B. F. Branstetter IV ([email protected]). 2 Department of Internal Medicine, University of Pittsburgh Medical Center, Pittsburgh, PA. Neuroradiology/Head and Neck Imaging • Original Research AJR 2016; 206:20–25 0361–803X/16/2061–20 © American Roentgen Ray Society H eadache after dural puncture is a well-established complication, whether puncture is performed at the bedside or under fluoroscopic guidance. Headache is thought to result from incomplete healing of the dural puncture, re- sulting in a CSF leak and decreased intracra- nial pressure. The intracranial hypotension causes traction on intracranial structures that stimulates pain fibers and results in a posi- tional headache that is most severe when standing [1]. Typically, patients remain at the treating facility after a fluoroscopically guid- ed dural puncture to assess for immediate complications and to promote healing of the dura. Patients are typically asked to remain supine during this observation period be- cause decreased CSF pressure at the puncture site is believed to allow more rapid closure of the dural defect. Bed rest has been prescribed Keywords: complication rates, fluoroscopy, headache, interventional radiology, lumbar puncture, myelogram DOI:10.2214/AJR.15.14664 Received March 2, 2015; accepted after revision June 23, 2015. FOCUS ON: JOURNAL CLUB OBJECTIVE. Headaches due to CSF leak are a well-described complication of dural puncture. It is uncertain how long patients should be observed after dural puncture to reduce the risk of headache. Most of the literature has focused on dural punctures performed without fluoroscopic guidance. The purpose of this study was to determine the incidence of complica- tions from fluoroscopically guided dural punctures, with attention to predictive factors such as the length of bed rest after the procedure. MATERIALS AND METHODS. We retrospectively reviewed 2141 fluoroscopically guided dural punctures performed over a 5-year period by a single radiology practitioner as- sistant. All patients were contacted 48–72 hours after the procedure to assess for compli- cations. Complications were categorized according to whether the patient reported having severe headache (requiring epidural blood patch for treatment), any headache, or any com- plaint. Using a multivariate logistic regression model, we assessed several possible predic- tors of complication: patient age, patient sex, needle caliber, puncture site, distance driven after recovery, length of postprocedural bed rest, contrast concentration, and contrast volume. RESULTS. In all, 0.8% of patients reported having a severe headache, 2.2% reported having any headache, and 2.6% reported having any complaint. In the multivariate analysis, age and sex were predictive of complication rates (with younger women having higher rates), but the other variables were not predictive. In particular, length of postprocedural bed rest showed statistical equivalence. CONCLUSION. Fluoroscopically guided dural punctures result in few complications compared with lumbar punctures performed without fluoroscopic guidance. Postprocedural bed rest greater than 2 hours does not reduce complication rates for fluoroscopically guided lumbar punctures. Rodriguez et al. Fluoroscopically Guided Lumbar Punctures and Myelograms Neuroradiology/Head and Neck Imaging Original Research Downloaded from www.ajronline.org by 171.243.0.161 on 03/06/23 from IP address 171.243.0.161. Copyright ARRS. For personal use only; all rights reserved
Welcome message from author
This document is posted to help you gain knowledge. Please leave a comment to let me know what you think about it! Share it to your friends and learn new things together.
Transcript
JOURNAL CLUB: Incidence of Complications Following Fluoroscopically Guided Lumbar Punctures and Myelograms20 AJR:206, January 2016
for as long as 24 hours, necessitating an over- night stay in the hospital for a dural puncture. Dural puncture is now commonly performed as an outpatient procedure with a much short- er observation period because lengthy obser- vation was not found to significantly decrease the risk of headache [2]. The initial treatment of headache after a dural puncture is conser- vative management including increased fluid intake, acetaminophen, nonsteroidal antiin- flammatory drugs, opioids, and antiemetics [1]. Refractory headaches may require addi- tional intervention such as an epidural blood patch for treatment [3].
Most of the literature describing compli- cations of dural puncture was written by an- esthesiologists and neurologists because of their roles in obstetric anesthesia and lum- bar punctures. Thus, the existing literature on headache after dural puncture has chiefly
JOURNAL CLUB:
David Rodriguez1
Rodriguez D, Branstetter BF IV, Agarwal V, et al.
1Department of Radiology, University of Pittsburgh Medical Center, 200 Lothrop St, PUH Rm D132, Pittsburgh, PA 15213. Address correspondence to B. F. Branstetter IV ([email protected]).
2Department of Internal Medicine, University of Pittsburgh Medical Center, Pittsburgh, PA.
Neuroradiolog y/Head and Neck Imaging • Or ig ina l Research
AJR 2016; 206:20–25
H eadache after dural puncture is a well-established complication, whether puncture is performed at the bedside or under fluoroscopic
guidance. Headache is thought to result from incomplete healing of the dural puncture, re- sulting in a CSF leak and decreased intracra- nial pressure. The intracranial hypotension causes traction on intracranial structures that stimulates pain fibers and results in a posi- tional headache that is most severe when standing [1]. Typically, patients remain at the treating facility after a fluoroscopically guid- ed dural puncture to assess for immediate complications and to promote healing of the dura. Patients are typically asked to remain supine during this observation period be- cause decreased CSF pressure at the puncture site is believed to allow more rapid closure of the dural defect. Bed rest has been prescribed
Keywords: complication rates, fluoroscopy, headache, interventional radiology, lumbar puncture, myelogram
DOI:10.2214/AJR.15.14664
Received March 2, 2015; accepted after revision June 23, 2015.
FO CU
S O
JOURNAL CLUB
OBJECTIVE. Headaches due to CSF leak are a well-described complication of dural puncture. It is uncertain how long patients should be observed after dural puncture to reduce the risk of headache. Most of the literature has focused on dural punctures performed without fluoroscopic guidance. The purpose of this study was to determine the incidence of complica- tions from fluoroscopically guided dural punctures, with attention to predictive factors such as the length of bed rest after the procedure.
MATERIALS AND METHODS. We retrospectively reviewed 2141 fluoroscopically guided dural punctures performed over a 5-year period by a single radiology practitioner as- sistant. All patients were contacted 48–72 hours after the procedure to assess for compli- cations. Complications were categorized according to whether the patient reported having severe headache (requiring epidural blood patch for treatment), any headache, or any com- plaint. Using a multivariate logistic regression model, we assessed several possible predic- tors of complication: patient age, patient sex, needle caliber, puncture site, distance driven after recovery, length of postprocedural bed rest, contrast concentration, and contrast volume.
RESULTS. In all, 0.8% of patients reported having a severe headache, 2.2% reported having any headache, and 2.6% reported having any complaint. In the multivariate analysis, age and sex were predictive of complication rates (with younger women having higher rates), but the other variables were not predictive. In particular, length of postprocedural bed rest showed statistical equivalence.
CONCLUSION. Fluoroscopically guided dural punctures result in few complications compared with lumbar punctures performed without fluoroscopic guidance. Postprocedural bed rest greater than 2 hours does not reduce complication rates for fluoroscopically guided lumbar punctures.
Rodriguez et al. Fluoroscopically Guided Lumbar Punctures and Myelograms
Neuroradiology/Head and Neck Imaging Original Research
D ow
nl oa
de d
fr om
w w
w .a
jr on
lin e.
or g
by 1
71 .2
43 .0
.1 61
o n
03 /0
6/ 23
f ro
m I
P ad
dr es
s 17
1. 24
3. 0.
16 1.
C op
yr ig
ht A
R R
S. F
or p
er so
Fluoroscopically Guided Lumbar Punctures and Myelograms
dealt with nonfluoroscopically guided lum- bar punctures performed at the bedside. The reported incidence of headache after dural puncture varies from 5% to 37% [4, 5], but to our knowledge, the rate of headache after fluoroscopically guided dural puncture has not been investigated.
The purpose of this study was to deter- mine the incidence of complications after fluoroscopically guided dural puncture and to examine whether the duration of post- procedural bed rest was a significant predic- tor of complications.
Materials and Methods Subjects
This retrospective study was approved by our institutional review board and was HIPAA com- pliant. We retrospectively identified patients who underwent outpatient fluoroscopically guided du- ral punctures in the neuroradiology division of a single academic hospital. The patient list was de- rived from a departmental database that tracks spinal procedures, and data were supplemented from the electronic medical record. We included outpatients who underwent either a fluoroscopi- cally guided myelogram or a fluoroscopically guided lumbar puncture between September 1, 2009, and April 30, 2014. Only lumbar procedures were included; there were no thoracic or cervical punctures. All procedures were performed by a single radiology practitioner assistant, who main- tained patient logs throughout the study period. Inpatients and patients with discrepancies in ex- amination date or medical record number between the patient log and the electronic medical record were not included in the study. Inpatients were ex- cluded because we did not have a reliable means to track length of bed rest.
Our principal independent variable was length of postprocedural bed rest. We used a quasi-ex- perimental model to randomize this parameter. At the time of the study, our institution did not have a policy regarding the duration of postprocedural bed rest, so the duration was determined by the personal preference of the neuroradiologist sched- uled to supervise procedures for that day. Bed rest duration was ordered as either 2, 3, or 4 hours from the time of needle removal. Each neuroradi- ologist applied his or her preferred duration con- sistently, regardless of patient characteristics.
Procedures Included patients had a dural puncture proce-
dure, either a myelogram or lumbar puncture, using a C-arm fluoroscopic unit (OEC 9900, GE Health- care) for guidance. The thecal sac was punctured with either a 22- or a 25-gauge Quincke spinal nee-
dle. After dural puncture performed for a myelo- gram, iohexol (Omnipaque, GE Healthcare) was administered with a maximum dose of 3000 mg io- dine. After routine myelographic spot radiographs were obtained on the fluoroscopic table, the patient was transported to the CT scanner for imaging of the desired portion of the spine (cervical, thorac- ic, lumbar, or any combination of those areas). For lumbar punctures, the dura was traversed with a spinal needle, the opening pressure was measured in the prone position, and CSF samples were col- lected and sent for analysis. Periprocedural labora- tory work followed the consensus guidelines of the Society of Interventional Radiology [6]. Contrain- dications to dural puncture included space-occupy- ing lesions of the posterior fossa and cerebellar ton- sillar ectopia. We do not use conscious sedation for these procedures in our practice.
At the conclusion of the procedure, the patient was transported to a nursing observation unit with orders that the head of the patient’s bed be elevated no more than 30° during postprocedural bed rest. On discharge, the patient was provided with con- tact information and instructed to call the radiolo- gy practitioner assistant if any complications arose.
Assessment of Complications The radiology practitioner assistant contacted
each patient by telephone 48–72 hours after the procedure, queried to determine whether the pa- tient had any postprocedural complaints, and then specifically asked about headaches. Any com- plaint, including continuation of preprocedur- al symptoms, was included in our analysis. The patient was again instructed to call if any further complications occurred. If the patient was un- reachable at the first telephone call, the radiolo- gy practitioner assistant called daily until contact was made. All patients were eventually contacted.
The main complication of interest in our study was headache. Any complaint of headache was in- cluded in our analysis, whether it was positional in nature or was present before the procedure. When headache was reported, we routinely advised con- servative measures such as acetaminophen and bed rest with fluids for 24 hours. Although some phy- sicians suggest that patients with postprocedural headaches use caffeine, we do not routinely sug- gest this in our practice. If the headache persisted, the patient was offered a fluoroscopically guided epidural blood patch at the level of the puncture. For purposes of this study, “severe headache” re- fers to a postprocedural headache that required placement of an epidural blood patch.
We investigated whether the duration of post- procedural bed rest was predictive of the incidence of complications. This information was obtained from the electronic medical record, where physi-
cian orders for bed rest were recorded. Other data acquired from the electronic medical record were age at the time of the procedure, sex, caliber of puncture needle, type of procedure, site of punc- ture, indication for the procedure, concentration of intrathecal contrast material, volume of intra- thecal contrast material, and distance driven af- ter discharge. Two calibers of dural puncture nee- dle were used at our institution: 22 gauge and 25 gauge. The type of procedure was either myelo- gram or lumbar puncture. The dura was punctured at L2–L3, L3–L4, L4–L5, or through a previous lumbar laminectomy. The concentration of intra- thecal contrast material was 180, 240, or 300 mg I/mL. The presumed distance the patient drove after discharge was determined using the hospi- tal zip code as the starting location and the pa- tient’s home zip code listed in the electronic med- ical record as the endpoint. An online program was then used to calculate the driving distance be- tween the two zip codes [7]. When a patient re- sided within the same zip code as the hospital, a driving distance of 0 miles was recorded. We in- cluded driving distance as a potential confounder because time spent sitting in a car, either as driv- er or passenger, after a procedure could affect the CSF pressure in the lower spine, even after bed rest protocols were followed. Patients who resided more than 200 miles from the hospital were ex- cluded from the analysis of driving distance, be- cause they would be unlikely to travel the entire distance home on the same day as their procedure.
Statistical Analysis A multivariate logistic regression model was
used to assess predictors of complication. The in- dependent variables included in the model were pa- tient age, patient sex, caliber of puncture needle, type of procedure, site of puncture, length of post- procedural bed rest before discharge, and distance driven after discharge. The regression analysis was repeated three times: once for severe headache, once for any headache, and once for any complaint.
A similar analysis was performed including only patients who underwent myelography, in- cluding concentration and volume of contrast ma- terial as additional independent variables.
Because length of bed rest was the major focus of this study and our hypothesis was that bed rest was not a predictor of complication rates, we ad- ditionally performed equivalence testing, using a 95% CI for differences of percentages [8] in pair- wise fashion between the three categories of bed rest [9]. We considered an equivalence threshold of 1% absolute difference between complication rates to be the smallest clinically relevant difference.
In all analyses, p values less than or equal to 0.05 were considered significant.
D ow
nl oa
de d
fr om
w w
w .a
jr on
lin e.
or g
by 1
71 .2
43 .0
.1 61
o n
03 /0
6/ 23
f ro
m I
P ad
dr es
s 17
1. 24
3. 0.
16 1.
C op
yr ig
ht A
R R
S. F
or p
er so
Results A total of 3096 patients were identified
from our patient log. Of this number, 748 were excluded because they were inpatients, 168 were excluded due to date discrepancy, and 39 were excluded for discrepant medical record numbers, leaving 2141 patients eligible for analysis. For the analysis of driving dis- tance, an additional 21 patients were exclud- ed because their listed home zip codes were greater than 200 miles from the hospital.
Table 1 lists the characteristics of patients in our cohort. Mean patient age was 57 years (range, 18–96 years). The most common in- dications for myelography were neurolog- ic radicular symptoms (1249 patients, 66%) and back pain (218 patients, 12%). The most common indications for lumbar puncture were exclusion of malignancy (94 patients, 36%), normal pressure hydrocephalus (59 patients, 23%), and infectious or inflamma- tory process (49 patients, 19%).
Of the 2141 patients included in our analy- sis, 56 reported a postprocedural complaint (2.6%; 95% CI, 2.0–3.4%) (Table 1). Of the 56 postprocedural complaints, 48 (86%) were headache (2.2% of all patients; 95% CI,
1.7–3.0%). Of the 48 headaches, 18 (38%) re- quired an epidural blood patch for symptom relief (0.8% of all patients; 95% CI, 0.5– 1.3%). Women had complications more of- ten than did men. This difference was most notable for severe headaches; 1.4% of wom- en and 0.5% of men reported a severe head- ache (p < 0.05) (Table 1).
In addition to headache, the following complications were reported or observed: three patients with low back pain and one pa- tient each with skin soreness at the puncture site, hives from myelographic contrast mate- rial, nausea from myelographic constant ma- terial, gait instability, and induction of known ocular migraines. No hemorrhagic or infec- tious complications were seen in our series. Over the course of our study, one patient had a seizure during a combined cervical-lumbar myelogram. This patient was immediately admitted to the hospital and was thus exclud- ed from our analysis of outpatient events.
The mean age of patients reporting no complaint was 57 years; patients reporting any complaint, headache, or severe head- ache were on average younger (Table 2). The mean distance driven home from the hospi-
tal for patients not reporting a complaint was less than that for patients reporting any com- plaint (Table 2).
Multivariate analysis showed that the in- cidence of severe headache was affected by age and sex, with younger women more likely to a statistically significant degree to have this complication. The incidence of any headache was significantly predicted only by age, with younger patients more likely to in- cur them. Incidence of any complaint cor- related significantly with younger age and puncture at the L3–L4 level.
Variables that were not predictive of post- procedural complications were needle caliber (22-gauge versus 25-gauge), type of procedure (lumbar puncture versus myelogram), driv- ing distance after procedure, concentration of contrast material, volume of contrast materi- al injected, and length of postprocedural bed rest. Equivalence testing showed no clinical- ly significant difference in complication rates after different lengths of bed rest. Analyzing all complaints, the odds ratio for 2 hours ver- sus 4 hours was 0.98, 0.81 for 2 hours versus 3 hours, and 1.21 for 3 hours versus 4 hours.
Discussion Our study shows that, in patients who have
undergone fluoroscopically guided lumbar puncture, postprocedural bed rest beyond the first 2 hours has no bearing on the incidence of complications, particularly headache. This outcome agrees with recent reports that preventive measures have not reduced post- procedural headaches after nonfluoroscopi- cally guided lumbar punctures [10].
Our results may help to optimize guide- lines for postprocedural observation, par- ticularly in light of the differing lengths of postprocedural bed rest ordered. Our data follow an evolving trend over the past sev-
TABLE 1: Complications From Fluoroscopically Guided Dural Punctures ( Categoric Variables)
Categoric Variable No. of Patients Severe Headache Any Headache Any Complaint
Sex
Needle caliber
Procedure
Myelography 1883 18 (1.0) 44 (2.3) 51 (2.7)
Site
L2–L3 419 1 (0.2) 3 (0.7) 3 (0.7)
L3–L4 270 1 (0.4) 5 (1.9)a 6 (2.2)
L4–L5 26 0 (0.0) 0 (0.0) 0 (0.0)
Length of bed rest
2 h 294 3 (1.0) 6 (2.0) 7 (2.4)
3 h 779 6 (0.8) 19 (2.4) 23 (3.0)
4 h 1068 9 (0.8) 23 (2.2) 26 (2.4)
All patients 2141 18 (0.8) 48 (2.2) 56 (2.6)
Note—Due to incomplete patient data, the number of patients in each category may not add to 2141. Numbers in parentheses are percentage of total patients.
ap < 0.05.
Complication Age (y)
Severe headache 47 ± 15a 63 ± 64
Any headache 48 ± 14a 57 ± 57
Any complaint 47 ± 14a 53 ± 56
No complaint 57 ± 14 42 ± 95
Note—Data are presented as mean ± SD. ap < 0.05; statistically significant difference from patients with no complaint.
D ow
nl oa
de d
fr om
w w
w .a
jr on
lin e.
or g
by 1
71 .2
43 .0
.1 61
o n
03 /0
6/ 23
f ro
m I
P ad
dr es
s 17
1. 24
3. 0.
16 1.
C op
yr ig
ht A
R R
S. F
or p
er so
Fluoroscopically Guided Lumbar Punctures and Myelograms
eral decades as dural puncture procedures have moved from inpatient procedures to outpatient procedures with discharge after a short observation [11]. Our results show that lengthy postprocedural observations can be safely avoided, which may reduce the need for nurse staffing. Patients will also benefit by re- turning home sooner after their procedure.
We do not advocate complete elimination of postprocedural bed rest, as has been suggested by some authors [10]. All of our patients had at least 2 hours of bed rest, so we do not have data to support lesser recovery times. Furthermore, any invasive procedure should elicit some de- gree of postprocedural monitoring. We cur- rently advocate 2 hours of bed rest after fluo- roscopically guided dural puncture. Further studies may reveal equivalence of even shorter lengths of postprocedural bed rest.
The incidence of postprocedural head- ache for our fluoroscopically guided dural punctures (2.2%) was significantly lower than the existing literature for nonfluoro- scopically guided procedures, which rang- es from 20.5% to 26.4% [10]. Few data have been published regarding fluoroscopically guided dural punctures, but one large study by Hatfield et al. [12] addressed the use of blood patches after fluoroscopically guided dural punctures and found they were used in 4.2–29.6% of cases. The reason our com- plication rate for fluoroscopically guided dural puncture is significantly lower than in that study is uncertain but may be relat- ed to differences in technique, patient se- lection, or both. At our institution, lumbar punctures are sometimes performed un- der fluoroscopic guidance after unsuccess- ful bedside procedures, which can occur in elderly patients with significant spinal de- generative disease or in obese patients in whom bony landmarks cannot be reliably palpated. We hypothesize that dural punc- tures made under fluoroscopic guidance can be achieved with a smaller number of needle punctures, thus reducing opportuni- ties for complications to occur. Another po- tential explanation is the difference in pa- tient position: Fluoroscopic punctures are performed with the patient prone, whereas nonfluoroscopically guided procedures are generally performed in a seated or lateral decubitus position. The increasing reliance on fluoroscopic guidance for lumbar punc- tures [13] may be in part attributable to rec- ognition of these differences.
The belief that using a larger gauge nee- dle increases the risk of…
for as long as 24 hours, necessitating an over- night stay in the hospital for a dural puncture. Dural puncture is now commonly performed as an outpatient procedure with a much short- er observation period because lengthy obser- vation was not found to significantly decrease the risk of headache [2]. The initial treatment of headache after a dural puncture is conser- vative management including increased fluid intake, acetaminophen, nonsteroidal antiin- flammatory drugs, opioids, and antiemetics [1]. Refractory headaches may require addi- tional intervention such as an epidural blood patch for treatment [3].
Most of the literature describing compli- cations of dural puncture was written by an- esthesiologists and neurologists because of their roles in obstetric anesthesia and lum- bar punctures. Thus, the existing literature on headache after dural puncture has chiefly
JOURNAL CLUB:
David Rodriguez1
Rodriguez D, Branstetter BF IV, Agarwal V, et al.
1Department of Radiology, University of Pittsburgh Medical Center, 200 Lothrop St, PUH Rm D132, Pittsburgh, PA 15213. Address correspondence to B. F. Branstetter IV ([email protected]).
2Department of Internal Medicine, University of Pittsburgh Medical Center, Pittsburgh, PA.
Neuroradiolog y/Head and Neck Imaging • Or ig ina l Research
AJR 2016; 206:20–25
H eadache after dural puncture is a well-established complication, whether puncture is performed at the bedside or under fluoroscopic
guidance. Headache is thought to result from incomplete healing of the dural puncture, re- sulting in a CSF leak and decreased intracra- nial pressure. The intracranial hypotension causes traction on intracranial structures that stimulates pain fibers and results in a posi- tional headache that is most severe when standing [1]. Typically, patients remain at the treating facility after a fluoroscopically guid- ed dural puncture to assess for immediate complications and to promote healing of the dura. Patients are typically asked to remain supine during this observation period be- cause decreased CSF pressure at the puncture site is believed to allow more rapid closure of the dural defect. Bed rest has been prescribed
Keywords: complication rates, fluoroscopy, headache, interventional radiology, lumbar puncture, myelogram
DOI:10.2214/AJR.15.14664
Received March 2, 2015; accepted after revision June 23, 2015.
FO CU
S O
JOURNAL CLUB
OBJECTIVE. Headaches due to CSF leak are a well-described complication of dural puncture. It is uncertain how long patients should be observed after dural puncture to reduce the risk of headache. Most of the literature has focused on dural punctures performed without fluoroscopic guidance. The purpose of this study was to determine the incidence of complica- tions from fluoroscopically guided dural punctures, with attention to predictive factors such as the length of bed rest after the procedure.
MATERIALS AND METHODS. We retrospectively reviewed 2141 fluoroscopically guided dural punctures performed over a 5-year period by a single radiology practitioner as- sistant. All patients were contacted 48–72 hours after the procedure to assess for compli- cations. Complications were categorized according to whether the patient reported having severe headache (requiring epidural blood patch for treatment), any headache, or any com- plaint. Using a multivariate logistic regression model, we assessed several possible predic- tors of complication: patient age, patient sex, needle caliber, puncture site, distance driven after recovery, length of postprocedural bed rest, contrast concentration, and contrast volume.
RESULTS. In all, 0.8% of patients reported having a severe headache, 2.2% reported having any headache, and 2.6% reported having any complaint. In the multivariate analysis, age and sex were predictive of complication rates (with younger women having higher rates), but the other variables were not predictive. In particular, length of postprocedural bed rest showed statistical equivalence.
CONCLUSION. Fluoroscopically guided dural punctures result in few complications compared with lumbar punctures performed without fluoroscopic guidance. Postprocedural bed rest greater than 2 hours does not reduce complication rates for fluoroscopically guided lumbar punctures.
Rodriguez et al. Fluoroscopically Guided Lumbar Punctures and Myelograms
Neuroradiology/Head and Neck Imaging Original Research
D ow
nl oa
de d
fr om
w w
w .a
jr on
lin e.
or g
by 1
71 .2
43 .0
.1 61
o n
03 /0
6/ 23
f ro
m I
P ad
dr es
s 17
1. 24
3. 0.
16 1.
C op
yr ig
ht A
R R
S. F
or p
er so
Fluoroscopically Guided Lumbar Punctures and Myelograms
dealt with nonfluoroscopically guided lum- bar punctures performed at the bedside. The reported incidence of headache after dural puncture varies from 5% to 37% [4, 5], but to our knowledge, the rate of headache after fluoroscopically guided dural puncture has not been investigated.
The purpose of this study was to deter- mine the incidence of complications after fluoroscopically guided dural puncture and to examine whether the duration of post- procedural bed rest was a significant predic- tor of complications.
Materials and Methods Subjects
This retrospective study was approved by our institutional review board and was HIPAA com- pliant. We retrospectively identified patients who underwent outpatient fluoroscopically guided du- ral punctures in the neuroradiology division of a single academic hospital. The patient list was de- rived from a departmental database that tracks spinal procedures, and data were supplemented from the electronic medical record. We included outpatients who underwent either a fluoroscopi- cally guided myelogram or a fluoroscopically guided lumbar puncture between September 1, 2009, and April 30, 2014. Only lumbar procedures were included; there were no thoracic or cervical punctures. All procedures were performed by a single radiology practitioner assistant, who main- tained patient logs throughout the study period. Inpatients and patients with discrepancies in ex- amination date or medical record number between the patient log and the electronic medical record were not included in the study. Inpatients were ex- cluded because we did not have a reliable means to track length of bed rest.
Our principal independent variable was length of postprocedural bed rest. We used a quasi-ex- perimental model to randomize this parameter. At the time of the study, our institution did not have a policy regarding the duration of postprocedural bed rest, so the duration was determined by the personal preference of the neuroradiologist sched- uled to supervise procedures for that day. Bed rest duration was ordered as either 2, 3, or 4 hours from the time of needle removal. Each neuroradi- ologist applied his or her preferred duration con- sistently, regardless of patient characteristics.
Procedures Included patients had a dural puncture proce-
dure, either a myelogram or lumbar puncture, using a C-arm fluoroscopic unit (OEC 9900, GE Health- care) for guidance. The thecal sac was punctured with either a 22- or a 25-gauge Quincke spinal nee-
dle. After dural puncture performed for a myelo- gram, iohexol (Omnipaque, GE Healthcare) was administered with a maximum dose of 3000 mg io- dine. After routine myelographic spot radiographs were obtained on the fluoroscopic table, the patient was transported to the CT scanner for imaging of the desired portion of the spine (cervical, thorac- ic, lumbar, or any combination of those areas). For lumbar punctures, the dura was traversed with a spinal needle, the opening pressure was measured in the prone position, and CSF samples were col- lected and sent for analysis. Periprocedural labora- tory work followed the consensus guidelines of the Society of Interventional Radiology [6]. Contrain- dications to dural puncture included space-occupy- ing lesions of the posterior fossa and cerebellar ton- sillar ectopia. We do not use conscious sedation for these procedures in our practice.
At the conclusion of the procedure, the patient was transported to a nursing observation unit with orders that the head of the patient’s bed be elevated no more than 30° during postprocedural bed rest. On discharge, the patient was provided with con- tact information and instructed to call the radiolo- gy practitioner assistant if any complications arose.
Assessment of Complications The radiology practitioner assistant contacted
each patient by telephone 48–72 hours after the procedure, queried to determine whether the pa- tient had any postprocedural complaints, and then specifically asked about headaches. Any com- plaint, including continuation of preprocedur- al symptoms, was included in our analysis. The patient was again instructed to call if any further complications occurred. If the patient was un- reachable at the first telephone call, the radiolo- gy practitioner assistant called daily until contact was made. All patients were eventually contacted.
The main complication of interest in our study was headache. Any complaint of headache was in- cluded in our analysis, whether it was positional in nature or was present before the procedure. When headache was reported, we routinely advised con- servative measures such as acetaminophen and bed rest with fluids for 24 hours. Although some phy- sicians suggest that patients with postprocedural headaches use caffeine, we do not routinely sug- gest this in our practice. If the headache persisted, the patient was offered a fluoroscopically guided epidural blood patch at the level of the puncture. For purposes of this study, “severe headache” re- fers to a postprocedural headache that required placement of an epidural blood patch.
We investigated whether the duration of post- procedural bed rest was predictive of the incidence of complications. This information was obtained from the electronic medical record, where physi-
cian orders for bed rest were recorded. Other data acquired from the electronic medical record were age at the time of the procedure, sex, caliber of puncture needle, type of procedure, site of punc- ture, indication for the procedure, concentration of intrathecal contrast material, volume of intra- thecal contrast material, and distance driven af- ter discharge. Two calibers of dural puncture nee- dle were used at our institution: 22 gauge and 25 gauge. The type of procedure was either myelo- gram or lumbar puncture. The dura was punctured at L2–L3, L3–L4, L4–L5, or through a previous lumbar laminectomy. The concentration of intra- thecal contrast material was 180, 240, or 300 mg I/mL. The presumed distance the patient drove after discharge was determined using the hospi- tal zip code as the starting location and the pa- tient’s home zip code listed in the electronic med- ical record as the endpoint. An online program was then used to calculate the driving distance be- tween the two zip codes [7]. When a patient re- sided within the same zip code as the hospital, a driving distance of 0 miles was recorded. We in- cluded driving distance as a potential confounder because time spent sitting in a car, either as driv- er or passenger, after a procedure could affect the CSF pressure in the lower spine, even after bed rest protocols were followed. Patients who resided more than 200 miles from the hospital were ex- cluded from the analysis of driving distance, be- cause they would be unlikely to travel the entire distance home on the same day as their procedure.
Statistical Analysis A multivariate logistic regression model was
used to assess predictors of complication. The in- dependent variables included in the model were pa- tient age, patient sex, caliber of puncture needle, type of procedure, site of puncture, length of post- procedural bed rest before discharge, and distance driven after discharge. The regression analysis was repeated three times: once for severe headache, once for any headache, and once for any complaint.
A similar analysis was performed including only patients who underwent myelography, in- cluding concentration and volume of contrast ma- terial as additional independent variables.
Because length of bed rest was the major focus of this study and our hypothesis was that bed rest was not a predictor of complication rates, we ad- ditionally performed equivalence testing, using a 95% CI for differences of percentages [8] in pair- wise fashion between the three categories of bed rest [9]. We considered an equivalence threshold of 1% absolute difference between complication rates to be the smallest clinically relevant difference.
In all analyses, p values less than or equal to 0.05 were considered significant.
D ow
nl oa
de d
fr om
w w
w .a
jr on
lin e.
or g
by 1
71 .2
43 .0
.1 61
o n
03 /0
6/ 23
f ro
m I
P ad
dr es
s 17
1. 24
3. 0.
16 1.
C op
yr ig
ht A
R R
S. F
or p
er so
Results A total of 3096 patients were identified
from our patient log. Of this number, 748 were excluded because they were inpatients, 168 were excluded due to date discrepancy, and 39 were excluded for discrepant medical record numbers, leaving 2141 patients eligible for analysis. For the analysis of driving dis- tance, an additional 21 patients were exclud- ed because their listed home zip codes were greater than 200 miles from the hospital.
Table 1 lists the characteristics of patients in our cohort. Mean patient age was 57 years (range, 18–96 years). The most common in- dications for myelography were neurolog- ic radicular symptoms (1249 patients, 66%) and back pain (218 patients, 12%). The most common indications for lumbar puncture were exclusion of malignancy (94 patients, 36%), normal pressure hydrocephalus (59 patients, 23%), and infectious or inflamma- tory process (49 patients, 19%).
Of the 2141 patients included in our analy- sis, 56 reported a postprocedural complaint (2.6%; 95% CI, 2.0–3.4%) (Table 1). Of the 56 postprocedural complaints, 48 (86%) were headache (2.2% of all patients; 95% CI,
1.7–3.0%). Of the 48 headaches, 18 (38%) re- quired an epidural blood patch for symptom relief (0.8% of all patients; 95% CI, 0.5– 1.3%). Women had complications more of- ten than did men. This difference was most notable for severe headaches; 1.4% of wom- en and 0.5% of men reported a severe head- ache (p < 0.05) (Table 1).
In addition to headache, the following complications were reported or observed: three patients with low back pain and one pa- tient each with skin soreness at the puncture site, hives from myelographic contrast mate- rial, nausea from myelographic constant ma- terial, gait instability, and induction of known ocular migraines. No hemorrhagic or infec- tious complications were seen in our series. Over the course of our study, one patient had a seizure during a combined cervical-lumbar myelogram. This patient was immediately admitted to the hospital and was thus exclud- ed from our analysis of outpatient events.
The mean age of patients reporting no complaint was 57 years; patients reporting any complaint, headache, or severe head- ache were on average younger (Table 2). The mean distance driven home from the hospi-
tal for patients not reporting a complaint was less than that for patients reporting any com- plaint (Table 2).
Multivariate analysis showed that the in- cidence of severe headache was affected by age and sex, with younger women more likely to a statistically significant degree to have this complication. The incidence of any headache was significantly predicted only by age, with younger patients more likely to in- cur them. Incidence of any complaint cor- related significantly with younger age and puncture at the L3–L4 level.
Variables that were not predictive of post- procedural complications were needle caliber (22-gauge versus 25-gauge), type of procedure (lumbar puncture versus myelogram), driv- ing distance after procedure, concentration of contrast material, volume of contrast materi- al injected, and length of postprocedural bed rest. Equivalence testing showed no clinical- ly significant difference in complication rates after different lengths of bed rest. Analyzing all complaints, the odds ratio for 2 hours ver- sus 4 hours was 0.98, 0.81 for 2 hours versus 3 hours, and 1.21 for 3 hours versus 4 hours.
Discussion Our study shows that, in patients who have
undergone fluoroscopically guided lumbar puncture, postprocedural bed rest beyond the first 2 hours has no bearing on the incidence of complications, particularly headache. This outcome agrees with recent reports that preventive measures have not reduced post- procedural headaches after nonfluoroscopi- cally guided lumbar punctures [10].
Our results may help to optimize guide- lines for postprocedural observation, par- ticularly in light of the differing lengths of postprocedural bed rest ordered. Our data follow an evolving trend over the past sev-
TABLE 1: Complications From Fluoroscopically Guided Dural Punctures ( Categoric Variables)
Categoric Variable No. of Patients Severe Headache Any Headache Any Complaint
Sex
Needle caliber
Procedure
Myelography 1883 18 (1.0) 44 (2.3) 51 (2.7)
Site
L2–L3 419 1 (0.2) 3 (0.7) 3 (0.7)
L3–L4 270 1 (0.4) 5 (1.9)a 6 (2.2)
L4–L5 26 0 (0.0) 0 (0.0) 0 (0.0)
Length of bed rest
2 h 294 3 (1.0) 6 (2.0) 7 (2.4)
3 h 779 6 (0.8) 19 (2.4) 23 (3.0)
4 h 1068 9 (0.8) 23 (2.2) 26 (2.4)
All patients 2141 18 (0.8) 48 (2.2) 56 (2.6)
Note—Due to incomplete patient data, the number of patients in each category may not add to 2141. Numbers in parentheses are percentage of total patients.
ap < 0.05.
Complication Age (y)
Severe headache 47 ± 15a 63 ± 64
Any headache 48 ± 14a 57 ± 57
Any complaint 47 ± 14a 53 ± 56
No complaint 57 ± 14 42 ± 95
Note—Data are presented as mean ± SD. ap < 0.05; statistically significant difference from patients with no complaint.
D ow
nl oa
de d
fr om
w w
w .a
jr on
lin e.
or g
by 1
71 .2
43 .0
.1 61
o n
03 /0
6/ 23
f ro
m I
P ad
dr es
s 17
1. 24
3. 0.
16 1.
C op
yr ig
ht A
R R
S. F
or p
er so
Fluoroscopically Guided Lumbar Punctures and Myelograms
eral decades as dural puncture procedures have moved from inpatient procedures to outpatient procedures with discharge after a short observation [11]. Our results show that lengthy postprocedural observations can be safely avoided, which may reduce the need for nurse staffing. Patients will also benefit by re- turning home sooner after their procedure.
We do not advocate complete elimination of postprocedural bed rest, as has been suggested by some authors [10]. All of our patients had at least 2 hours of bed rest, so we do not have data to support lesser recovery times. Furthermore, any invasive procedure should elicit some de- gree of postprocedural monitoring. We cur- rently advocate 2 hours of bed rest after fluo- roscopically guided dural puncture. Further studies may reveal equivalence of even shorter lengths of postprocedural bed rest.
The incidence of postprocedural head- ache for our fluoroscopically guided dural punctures (2.2%) was significantly lower than the existing literature for nonfluoro- scopically guided procedures, which rang- es from 20.5% to 26.4% [10]. Few data have been published regarding fluoroscopically guided dural punctures, but one large study by Hatfield et al. [12] addressed the use of blood patches after fluoroscopically guided dural punctures and found they were used in 4.2–29.6% of cases. The reason our com- plication rate for fluoroscopically guided dural puncture is significantly lower than in that study is uncertain but may be relat- ed to differences in technique, patient se- lection, or both. At our institution, lumbar punctures are sometimes performed un- der fluoroscopic guidance after unsuccess- ful bedside procedures, which can occur in elderly patients with significant spinal de- generative disease or in obese patients in whom bony landmarks cannot be reliably palpated. We hypothesize that dural punc- tures made under fluoroscopic guidance can be achieved with a smaller number of needle punctures, thus reducing opportuni- ties for complications to occur. Another po- tential explanation is the difference in pa- tient position: Fluoroscopic punctures are performed with the patient prone, whereas nonfluoroscopically guided procedures are generally performed in a seated or lateral decubitus position. The increasing reliance on fluoroscopic guidance for lumbar punc- tures [13] may be in part attributable to rec- ognition of these differences.
The belief that using a larger gauge nee- dle increases the risk of…
Related Documents
