The lumbar puncture. Patterns of use in clinical practice

Do Spinal Needle Sizes Affect the Development of Traumatic CSF in Neonatal LP Procedures?

Lumbar puncture (LP) is widely employed to evaluate infectious, neurological and metabolic diseases in the newborn. Neonatal LP is a difficult procedure with 45–54% success rates. Although there are studies examining traumatic LP failure, studies on the effects of needle sizes are limited. This study was intended to investigate the effect of needle sizes on LP traumatization. Term and premature babies who underwent LP in the neonatal intensive care unit between 30 November 2017 and 30 July 2019 were included in the study by retrospective file scanning. LP was performed by a pediatric or neonatal specialist using a 22 Gauge pen (G) or 25 G pen spinal needle in all cases, with all patients being placed in the lateral decubitus position. The primary outcome was to evaluate the effect of needle sizes used in LP on traumatization. The secondary outcome was to evaluate traumatization rates and complications. A statistically significant difference was determined in the rate of traumatized LP and desaturation development between needle sizes and CSF microscopic findings (p = 0.031, p = 0.005, and p = 0.006, respectively). The study data show that 25 G pen-tip spinal needles cause less traumatic LP in neonates than 22 G pen-tip spinal needles.

An educational video improves technique in performance of pediatric lumbar punctures

BACKGROUND

Unsuccessful or traumatic lumbar punctures (LPs) occur commonly and contribute to patient discomfort and to challenges in medical decision making in the pediatric emergency department (ED).

OBJECTIVE

We produced an instructional video demonstrating the best practices in pediatric LP technique. We hypothesized that the performance of LPs would change and the rate of successful LPs would increase after watching the video.

METHODS

This was a prospective study of LPs performed in an urban, academic pediatric ED before and after an educational intervention. Lumbar punctures performed during year 1 constituted the control arm. During year 2, all medical practitioners working in the ED watched the instructional video, and this constituted the interventional arm. The practitioner performing the LP completed a standardized data collection form after each LP procedure, and medical records were reviewed.

RESULTS

Data forms were collected on 668 LPs during the study period, 391 during year 1 and 277 during year 2. There was neither a significant change in overall LP success rate between the 2 years (56.8% year 1 vs 53.4% year 2) nor a significant difference in median number of LP attempts required per patient (P = 0.78). Seventy-eight percent of participants who viewed the LP video during year 2 stated that the video helped increase their comfort level with performing LPs. The odds of using the techniques endorsed in the educational video were significantly higher during year 2 compared to year 1 for use of local anesthetic, early stylet removal, and vertical patient position.

CONCLUSIONS

The video increased practitioners' comfort level with the performance of pediatric LPs and adherence to evidence-based best practices. It was not associated with an increased rate of successful LPs.

Predicting difficult and traumatic lumbar punctures

OBJECTIVE

The objective of this study is to determine if visual and tactile inspection of the spine is useful in the prediction of a difficult or traumatic lumbar puncture (LP).

DESIGN

This was a prospective, observational, cohort study conducted in the emergency department (ED) on patients who were undergoing an LP. Physicians prospectively completed a structured data form that included information about the patient, number of prior LPs performed, their assessment of the LP difficulty, and the number of needlesticks required. A "difficult" LP and a "traumatic" tap were defined a priori. Chi2, t tests, and regression were used as appropriate; an independent statistician performed the statistical analysis.

SETTING

The study was conducted at an urban university teaching hospital with an annual ED census of approximately 48,000 patients between November 1, 2002, and June 1, 2003.

PATIENTS

The study population included a convenience sample of patients undergoing LP in the ED.

RESULTS

Of the 148 patients enrolled, LP was difficult in 47 (32%) patients and traumatic in 23 (16%) patients. The percentage of patients that did not have a visible spine was significantly higher in the difficult and traumatic groups (P < .05). Among patients where the physician was unable to visualize the spine, there were significantly more difficult LPs (P < .05).

CONCLUSION

It may be possible to predict which patients will have difficult or traumatic LPs before performing the procedure. Simple bedside assessments of spine visibility and palpability may assist in planning the approach to an LP in patients.

Can cerebrospinal fluid uric acid levels differentiate intraventricular hemorrhage from traumatic tap?

OBJECTIVE

To measure blood and cerebrospinal fluid (CSF) uric acid (UA) levels of neonates with intraventricular hemorrhage (IVH), and to examine whether or not UA can be used to differentiate traumatic tap from IVH.

MATERIAL AND METHODS

The control group (n = 19, group I) consisted of neonates presenting with signs requiring analysis of CSF but whose CSF indices proved to be normal. Traumatic taps (n = 15, group II) were mimicked by adding 2 drops of homologous blood to normal CSF samples. The IVH group (n = 21, group III) consisted of neonates who had been diagnosed by cranial ultrasonography or computed tomography scans. Data are presented as median (range).

RESULTS

There was no significant difference between groups with respect to serum UA levels. While no significant difference was observed between CSF UA levels of the control [0.6 (0.1-1.8) mg/dl] and traumatic tap group [0.5 (0.3-1.1) mg/dl], the IVH group [1.6 (0.7-6.9) mg/dl] was found to have significantly higher CSF UA levels than groups I and II. Furthermore, although there were significant correlations between serum and CSF UA levels in the control and traumatic tap groups, no correlation was observed in the IVH group.

CONCLUSION

CSF UA levels are increased in neonates with IVH and they may be used to differentiate a real hemorrhage from a traumatic tap.

Perils and pitfalls of lumbar puncture in the emergency department

Lumbar Puncture is a procedure commonly performed in the emergency department. It provides important diagnostic information but has a significant number of limitations and complications. This article reviews the role of lumbar puncture in the emergency department based on an extensive review of the current literature, focusing on the recognized contraindications and complications of the procedure and how they can be minimized. The interpretation of diagnostic tests performed on cerebrospinal fluid is also examined, highlighting those tests most commonly ordered from the emergency department.

Xanthochromia revisited: a re-evaluation of lumbar puncture and CT scanning in the diagnosis of subarachnoid haemorrhage

The CT and cerebrospinal fluid (CSF) findings of 100 patients with ruptured intracranial aneurysms were reviewed. Forty six percent of the 68 patients who had a lumbar puncture had blood stained CSF but with no xanthochromia. There was no blood visible on the CT scan in 20 patients: seven of these 20 had blood in their CSF, but no xanthochromia. It is concluded that it is blood stained CSF that is important in the diagnosis of subarachnoid haemorrhage (SAH), and not xanthochromia, and that a normal CT scan (EMI 1010) and the absence of xanthochromia in the CSF do not exclude a ruptured intracranial aneurysm. To diagnose SAH, it may be necessary to perform both investigations; the CT scan as the primary investigation in those patients in whom lumbar puncture is judged to be hazardous; the lumbar puncture as the secondary investigation in those patients with a normal CT scan.

The use of lumbar puncture in a district general hospital

A survey of lumbar punctures performed in adults in a district general hospital over a two year period was carried out. As well as being used for conventional, specific indications, lumbar puncture was often employed as a screening investigation in undiagnosed neurological illness. Although this was not inappropriate in patients with meningeal symptoms and signs, or patients with disordered consciousness, lumbar puncture was also used in patients with focal neurological signs. Although the dangers of lumbar puncture in these latter patients, and the fact that it is unlikely to yield information unobtainable by other investigations have been stated by many authorities, almost 20% of patients fell into this group. This suggests that these points require further emphasis.

Evidence for an informal clinical policy resulting in high use of a very-low-yield test

The actual and self-reported practice regarding the use of cerebrospinal fluid cultures for Mycobacterium tuberculosis was examined. All neurology house staff members surveyed, 62 percent of internal medicine house staff members, and none of pediatric house staff members reported that they would order mycobacterial cultures of cerebrospinal fluid routinely. The actual practice was comparable, with 71 percent of cerebrospinal fluid specimens being subjected to culture for mycobacteria on the neurology service, 65 percent on the internal medicine service, and 6 percent on the pediatric service. In this practice, medicine and neurology house staff differ significantly from their pediatric colleagues (p less than 0.001) and from the stated practice of their respective faculties (p less than 0.01). For at least six years, most medicine and neurology house staff have commonly applied an informal clinical policy of routinely culturing cerebrospinal fluid specimens for mycobacteria, despite a low suspicion of disease, lack of faculty support for the practice, and a zero yield for the test. Informal clinical policies such as this may be an important contributor to the problem of technology overuse.

The role of lumbar puncture in the evaluation of dementia: the Durham Veterans Administration/Duke University Study

The use of lumbar puncture (LP) and cerebrospinal fluid (CSF) analysis in the routine, initial evaluation of patients with dementia continues to be questioned. This is especially true in the investigation of infectious causes of dementia. To explore this question further, the authors performed a retrospective analysis of 672 hospitalized patients specifically evaluated for dementia. LP and CSF analysis were performed on 402 patients (60 per cent); routine bacteriologic, acid-fast, and fungal cultures were also obtained for 333 of these patients. Most patients were white (64 per cent) and male (63 per cent), their mean age being 66 +/- 11 years. Four patients were diagnosed as having meningitis--two with Cryptococcus neoformans, one with apparent Mycobacterium tuberculosis, and one with coagulase-positive Staphylococcus aureus. These patients were characterized by a subacute change in mental status, fever or meningismus, and CSF pleocytosis with abnormal CSF chemistries. None of the patients were found to have newly diagnosed neurosyphilis. The authors conclude that LP and CSF analysis should not be part of the routine evaluation of patients with dementia and should be performed only in the presence of such indications as a subacute duration of dementia, fever, and signs of meningeal irritation.