Paper reading

主持人 : 鄭淵家 醫師報告人 :Intern 葉力仁

David H. Livingston, MD,* Robert F. Lavery, MA,* Marian R. Passannante, PhD,† Joan H. Skurnick, PhD,† Stephen Baker, MD,‡

Timothy C. Fabian, MD,§ Donald E. Fry, MD,i and Mark A. Malangoni, MD¶

From the Departments of *Surgery, †Preventive Medicine and Community Health, and ‡Radiology, New Jersey Medical School Newark, New Jersey, and the Departments of Surgery, the §University of Tennessee, Memphis, Tennessee, the iUniversity of New Mexico, Albuquerque, New Mexico, and ¶Case Western Reserve University, Cleveland, Ohio of Organs Dysfunctional

Emergency Department Discharge of Patients

With a Negative Cranial Computed Tomography

Scan After Minimal Head Injury

ANNALS OF SURGERYVol. 232, No. 1, 126–132© 2000 Lippincott Williams &

Wilkins, Inc.

No other body system No other body system injuriesinjuries

CT:CT:

no intracerebral injuryno intracerebral injuryMHIMHI

No any neurologic findingNo any neurologic finding

Conclusions

Discharge

MHI: Minimal Head Injury

Or 2.evidence of posttraumatic amnesia Or 2.evidence of posttraumatic amnesia + GCS:14-15+ GCS:14-15

1. Documented loss of consciousness 1. Documented loss of consciousness + GCS:14-15+ GCS:14-15

Diagnostic studies Diagnostic studies have excluded have excluded

intracranial injuryintracranial injury

Loss of Loss of consciousnessconsciousnessMHIMHI

Background-- Standard practice for pts with

head injury

Hospital admission or

prolonged observation

?1. Undefined false-negative rate

2. Medicolegal considerations

How much is the false-negative rate

• Method• 1. All patients > 16 years old• 2. Blunt head trauma• 3. Admitted to 4 lever 1 trauma centers• 4. Prospective• 5. Time: 22 months• 6. Standardized NE• 7. Noncontrast Cranial helical CT scanner

Definition of CT: Negative or Positive• Positive:• an intracranial injury was demonstrated.

•The need for intervention with a positive CT was determined by the neurosurgeons.

• Negative• No intracranial injury was considered with or

without extracranial injury• Equivocal:• when they could neither exclude nor determine the

presence of an intracranial injury.

After the CT• admitted and observed and the treatment of any other

injuries.

• The standardized neurologic examination:– 4 to 8 hours after arrival to the ED.

– and 20 hours after admission

– and at discharge for the outcomes:

• Outcomes: Neurologic deterioration, neurosurgical intervention, and death.

Deterioration • decrease of >= 2 points GCS

• focal neurologic abnormality

• a loss of orientation to person or place

• the need to ICU due to head injury

• the need for any neurosurgical intervention. – endotracheal intubation – mechanical ventilation– use anticonvulsants – to treat cerebral edema, or intracranial pressure monitoring– craniotomy.

Sampling size

Because the goal of this study was to 1.define a diagnostic evaluation

2.high negative predictive value (NPV) > 99.6% or more.

3.pts could be safely discharged from the ED

Sample size: 2569

Data Analysis (1/2)• To determine whether there were any center effects

or significant practice pattern variations • summaries of

– demographic information– baseline clinical status– site-specific data

• surgical reports and clinical course of all patients who required neurosurgical intervention after a negative cranial CT were reviewed.

• NPV

• true-negative results/(true-negative results + false-negative results).

• Lower 95% and 99% confidence limits were obtained for NPVs using the binomial probability distribution.

• This study was reviewed and approved by the institutional review boards at the four participating institutions.

Data Analysis (2/2)

25692569

were were enrolledenrolled

4568 4568

had signs of had signs of head traumahead trauma

64096409With With blunt blunt injuryinjury

Excluded 1999See table 1

Excluded 417See Table 2

21522152were were

studiedstudied

Results(1/3)

Table 1

Table 2

Results (2/3)

•Clinically unimportant differences were found in age, gender, and mechanism of injury between some of the sites

•Centers effects: demographic variables

• The mean Injury Severity Score for the entire population was 10.6 (95% CI 10.4 –10.9).

• There were no differences in Injury Severity Score between centers.

Table 4

Preliminary 的 CT 可不可信 ?

97 % Agreement

Conclusion• 5 patients (0.3%) had missed injuries on the

preliminary reading and required neurosurgical intervention. – 2 : increase in neurologic monitoring,– 2 :ICU admission and anticonvulsants 1:

underwent a craniotomy.– All recovered without sequelae.

• The NPV of the cranial CT scan based on the preliminary interpretation was 99.70%

•An analysis using the intent-to-treat group did not alter these results. •The NPV defined by the need for a craniotomy was 99.94%

Discussions

The data presented here clearly indicate cranial CT scan is necessary for patients who sustained either an LOC or posttraumatic amnesia

•2. Safe?

• 1. CT Necessary?

•patients with a cranial CT scan, shows no intracerebral injury and no other body system injuries or a persistence of any neurologic finding can safely be discharged from the ED

Thank you