Review or meta-analysis
Robinson N, Clancy MIn Patients with Head Injury Undergoing RSI, Does Pretreatment with IV Lidocaine Lead to an Improved Neurological Outcome? A Review of the Literature,
Emerg Med J
2001;18:453-457
- Submitted by:Dale Ray - Emergency Medicine Faculty
- Institution:Grand Rapids MERC/ Michigan State University, Grand Rapids, MI
- Date submitted:14th July 2006
1
Objectives and hypotheses
1.1
Are the objectives of the study clearly stated?
Yes -- in patients suffering a major head injury who undergo RSI, does pretreatment with IV lignocaine/lidocaine compared with no pretreatment lead to an improved neurological outcome?
2
Design
2.1
Is the study design suitable for the objectives?
Yes, a literature search was carried out to identify studies in which intravenous lidocaine was used as a pretreatment for RSI in major head injury. Any link to an improved neurological outcome was also sought.
2.2
Were the search methods used to locate relevant studies comprehensive?
Yes, although the authors could have also hand-searched journals and research symposiums as well as industry sponsored trials.
2.3
Was this the right sample to answer the objectives?
The patient population was those patients presenting to the emergency department with acute traumatic brain injury (< 12 hours from the time of injury) requiring RSI as a component of their emergency management. No such study was identified. The closest reported group were comatose patients suffering from closed traumatic head injury ventilated on intensive care units, already intubated. The other reported group were patients undergoing elective neurosurgery for tumours or intracranial aneurysms with or without pre-existing raised ICP.
2.4
Is the study large enough to achieve its objectives?
In part, six valid papers were found, which individually contained elements of the question posed and these are presented in a narrative and graphic form.
2.5
Were all the studies accounted for?
Yes
2.6
Were all appropriate outcomes considered?
The ideal outcome would be patient's neurological status at discharge or later. No paper reported this outcome and the surrogate marker of intracranial pressure change was used.
2.7
Has ethical approval been obtained if appropriate?
Not applicable
3
Measurement and observation
3.1
Is it clear what was measured, how it was measured and what the outcomes were?
The ideal outcome would be patient's neurological status at discharge or later. No paper reported this outcome and the surrogate marker of intracranial pressure change was used.
3.2
Were explicit methods used to determine which studies to include in the review?
The authors did not specify any inclusion or exclusion criteria relating to the study design. Prospective randomised controlled trials (RCTs) were included in the review. Observational studies were also included if they contained information directly relevant to the questions posed.
3.3
Was the selection of primary studies re-producible and free from bias?
The search strategy was well described and reproducible.
3.4
Was the methodologic quality of the primary studies assessed?
Yes, the included prospective randomised controlled trials were appraised according to 6criteria. The authors did not report any assessment of the methodological quality of the observational studies.
3.5
Are the measurements valid?
The authors do not state how the papers were assessed for validity, or how many of the reviewers performed the validity assessment
3.6
Are the measurements reliable?
Yes, the individual papers were summarised in a narrative form, and how close the papers came to answering the review question was illustrated graphically.
3.7
Are the measurements reproducible?
Yes, ICP measurements should be reproducible
4
Presentation of results
4.1
Are the basic data adequately described?
The individual papers were summarised in a narrative form.
4.2
Were the differences between studies adequately described?
The authors do not state a method for assessing any differences between the studies.
4.3
Are the results presented clearly, objectively and in sufficient detail to enable readers to make their own judgement?
Yes, the individual papers were summarised in a narrative form, and how close the papers came to answering the review question was illustrated graphically.
4.4
Are the results internally consistent, i.e. do the numbers add up properly?
Yes, six studies with a total of 98 participants were included in the review: 5 RCTs (89 participants) and one crossover cohort study (9 patients).
5
Analysis
5.1
Were the results of primary studies combined appropriately?
Studies were not combined
5.2
Has a sensitivity analysis been performed?
No
5.3
Were all the important outcomes considered?
The ideal outcome would be neurological status at discharge or later. No paper reported this outcome and the surrogate marker of intracranial pressure change was used.
5.4
Are the data suitable for analysis?
No, six studies of variable quality evaluated the impact of lidocaine before intubation on ICP changes. Studies were all small and of variable design prohibiting meta-analysis with conflicting results.
5.5
Are the methods appropriate to the data?
A limited description of the included studies was given in the text of the review, and from this it was apparent that the study populations and designs varied considerably.
5.6
Are any statistics correctly performed and interpreted?
No statistics were performed
6
Discussion
6.1
Are the results discussed in relation to existing knowledge on the subject and study objectives?
The authors' conclusions regarding the lack of evidence to justify pre-treatment with lignocaine (lidocaine) in the specified population appear valid.
6.2
Is the discussion biased?
No
7
Interpretation
7.1
Are the author's conclusions justified by the data?
Yes, there is no compelling evidence that in acute, traumatic brain injury that pre-treatment with IV lidocaine before RSI improves ICP or, more importantly, neurological outcomes (p. 457).
7.2
What level of evidence has this paper presented?
2a
7.3
Does this paper help me to answer my problem?
The most compelling evidence regarding the question of efficacy of lidocaine in RSI of head injured patients. Part of Cochrane Databases Database of Abstracts of Reviews of Systematic Effects (DARE) collection, last updated in 2005 without significant changes or additional studies identified. The authors conclusions appear valid: "There is currently no evidence to support the use of intravenous lidocaine as a pre-treatment for RSI in patients with head injury and its use should only occur in clinical trials." (p. 453)
8
Implementation
8.1
Can any necessary change be implemented in practice?
The administration of IV lignocaine/lidocaine as a pretreatment in patients with acute head injury undergoing RSI should only occur in clinical trials.
8.2
What aids to implementation exist?
There is currently no evidence to support the use of intravenous lignocaine (lidocaine) as a pre-treatment for RSI patients with head injury
8.3
What barriers to implementation exist?
This therapy is considered standard of care by many Emergency Medicine physicians in the US. A survey of Emergency Medicine Residency Programs in the United States (US) revealed that intravenous lignocaine/lidocaine was routinely administered prior to RSI in patients with major head injuries