cEEG Monitoring in the ICU: Treating Subclinical Seizures is

Cost Effective

Paul Vespa, MD, FCCM

UCLA Medical Center

NCS Meeting 2007

Disclosures

• No direct support from cEEG companies

• I am somewhat biased: I think that silence is not always golden

• I am dependent on my brain waves, hence I am predisposed to protecting them at all cost

Preliminary Remarks

• If we had definitive data on this question we would…– Know the answer already– Be bored with this topic– Be self-righteous about our response

• cEEG is by definition a monitor. Therefore it is a – Diagnostic tool– Objective instrument to define the effects of treatment– Biomarker against which to titrate the intensity of

treatment

Are nonconvulsive seizures a significant problem in the ICU?

• Yes!• 35% of NeuroICU patients found to have seizures (Jordan

1992)• 22% of TBI patients have seizures, ½ of which are

nonconvulsive (Vespa 1999)• 28% of ICH patients have seizures, ½ of which are

nonconvulsive (Vespa 2003)• 15% of SAH patients have seizures (Claassen 2004)• 44% of pediatric ICU patients have seizures on cEEG (Jette,

Hirsch 2006); 39% were nonconvulsive• 16% of pediatric ICU patients with mental status problems

(Snead et al 2006)

Is NCSE a significant problem in the ICU?

• Yes!• 8% of general ICU patients were found to be in NCSE using

routine portable 30 min EEG (Towne 2000)• 22% of TBI patients have seizures, 6% have NCSE (Vespa

1999)• 15% of mixed NICU patients have Nonconvulsive seizures,

4.5% had NCSE (Claassen 2004)• ~ 20% of pediatric ICU patients in Jette 2006 had NCSE• 11% of pediatric ICU patients with altered mental status have

NCSE (Narayanan 2007)

Dissecting the big question of effectiveness into smaller questions

• Effectiveness of a diagnostic test can be defined in many ways– Provides an accurate in diagnosis– Avoids risky testing to rule out other diagnoses– Permits optimal use of treatments and resources– Reduces cost– Improves clinical outcome

Let’s consider a common ICU monitor: EKG for detecting cardiac

arrythmias• Effectiveness of a diagnostic test can be

defined in many ways– Provides an accurate in diagnosis– Avoids risky testing to rule out other diagnoses– Permits optimal use of treatments and resources– Reduces cost– Improves clinical outcome

Importance

Is treating cardiac arrythmias cost effective?

• EKG is routinely performed on all ICU patients

• Costs of EKG are built into the daily ICU cost

• The incidence of threatening cardiac arrythmias in the Neuro-ICU is low (< 5 %)

• Prospective data about cost effectiveness of treating cardiac arrythmias is lacking

The setting in which Non-convulsive Seizures occurs may affect the

answer• Status epilepticus or soon thereafter• Primary structural brain injury• Systemic illness with transient,

superimposed brain dysfunction• Severe irreversible injury complicated by

seizures– Hypoxic ischemic injury– Severe TBI

Does EEG provide an accurate diagnosis of NC Seizures ?

• Yes

• Presence vs absence of seizures is reliably seen

Potential limitations of surface cEEG in detecting seizures

• Most seizures are not clinically suspected

• Some important electrical events, presently an unknown number, occur in the brain and escape detection by surface cEEG– DC depolarization events (Strong et al 2005)– Cortical seizures (unpublished observations)

Persistent NC Seizures after presenting with convulsive seizures

Privitera 1994• Emergency EEG, n=198, few clinical signs

• 37 % had nonconvulsive seizures

Does EEG provide an accurate diagnosis of NC Seizures ?

• Focal and generalized nonconvulsive seizures are accurately diagnosed by cEEG– Vespa 1999; Vespa 2003; Claassen 2004

• The timing, duration and frequency of seizures are reliably seen

Does EEG avoid risky testing to rule out other diagnoses ?

• Yes.

• EEG is noninvasive.

• If Seizures are seen, then other invasive testing is not required.– Caveat is that non-invasive testing (ie imaging)

is done

Does EEG permit optimal use of treatments and resources?

• Yes.• Anticonvulsant dosing in the presence of NCSz

can be titrated• Anticonvulant dosing can be stopped in the

absence of NC Sz– Naidech et al 2005: Phenytoin is associated with

functional and cognitive disability after SAH

– Chumnanjev et al 2007: Three day prophylaxis with phenytoin for SAH

Time to stopping status influences outcome

• Young, Jordan 1996: long latency to gaining control– latency to gaining control increased OR for mortality; < 2 hours

• Jaitly 1998: persistent epileptiform activity is frequent, associated with worse outcome

• Pellock 2004: time to treatment <30 minutes in less than 41.5% of 889 cases in Richmond

• Kalita 2006: EEG at 1 hour post clinical seizures is useful to tell who is controlled, and who will recur soon.

• Muaygil 2007: More rapid control is achieved when treatment protocols are followed

• Therefore, it is critical to document that the status epilepticus has stopped by EEG.

Mortality increases with the duration of Mortality increases with the duration of undiagnosed and untreated seizuresundiagnosed and untreated seizures

• Etiology:– Remote symptomatic: 16% (4/25) p = 0.009– Acute symptomatic: 46% (11/24) OR = 6.0

• NCS only vs. NCSE p = 0.002 - 12% vs. 54% OR=10.0

• Seizure Duration:– <10 h: 10% (3/30) p = 0.0006– 10-20 h: 33% (2/6) OR = 1.093/h– >20 h: 85% (11/13)

• Delay to Diagnosis– <0.5 h: 36% (5/14)– >1 <24 h: 39% (7/18) p = 0.00001 24 h: 75% (6/8)

* Young GB, Jordan KG., Doig G. Neurology, 1996

OR 1.039/h

Does EEG permit optimal use of treatments and resources for NC Sz?• UCLA preliminary data• cEEG monitoring applied to patients suspected to

have seizures upon admission to the ICU• Convenience retrospective cohort of patients

admitted to ICU with suspected or witnessed seizure(s)– N = 123

• Group 1: 100 had ongoing or intermittent non-convulsive seizures

• Group 2: 23 had no further seizures

UCLA retrospective data• Group 1: still seizing (n = 100)

– Mixed diagnoses: TBI, SAH, Status, Tumors, ICH– Uniformly treated with additional AEDs– IV drips titrated to stop seizures in 62%– Effective in diagnosis and titration of drugs in all cases– Avoidance of additional invasive testing or procedures

• 22/100 avoided angiography (SAH, AVM)• 9/100 avoided EVD/Surgery (tumor, hydro)

– Cost savings: (Estimates)• 31/100 estimated avoidance of costs for angio or surgery + 1

day of ICH LOS due to prompt diagnosis• 69/100 estimated 1 day savings due to prompt diagnosis• Cost/day of ICU stay = $1600-2000/day

UCLA retrospective data

• Group 2: not seizing on cEEG (n = 23)– Uniformly treated with once daily AED– Avoided IV drip or additional benzodiazepine– No avoidance of additional testing

• This is variable due to diagnoses

– No estimated cost savings • This may be too conservative, but unable to measure

Costs of doing cEEG at UCLA• Expenses

– Half-time EEG tech daytime, salary, benefits, nonproductive time $200/day

– Evening and night tech call back at overtime rate, 3hr/night* $225/day

– On-call pay $50/day– Total fixed $475/d– Supplies: disposable needles, etc. $15/pt/day

• Out of 19 bed ICU, 7 pts/day $105/day• Tech cost of cEEG monitoring/day/= $475/7 =

$68/pt/day+105 supplies/pt= $173/pt

* Excludes purchase price for cEEG system ~ $25-30,000/machine

Cost Savings due to reduction in ICU LOS in SAH with NC seizures

• If Nonconvulsive seizures are present, and cEEG is done, then NCSz will be seen and treated

• Only SAH pts considered for this• 2005-2006 data set with uniform cEEG performed for mean 4 days• Conservative estimate of Savings by reducing 1 day ICU LOS in

those pts who are found to be seizing• (Cost/day of ICU) x (# particular Dx) x (% seizing)• SAH = $1655 x 110 x 20% = $36,410

• Net cost reduction = Cost of cEEG – Savings• ($69/day x 110 x 4 days) - $36,410 =

– 30,360 – 36,410 = - $6050 • Save $6050/year by using cEEG, while providing more

comprehensive treatment

Overall Net Profit for cEEG in SAH

• The ICU LOS cost savings is not the whole story, since there is hospital revenue from cEEG– UCLA Estimate is $165/day revenue

– For SAH: Daily revenue x # days x # pts• $165 x 4 x 110 = $72,600/ year

• So, net revenue– $72,600 + $6050 = $78,650 profit

– This is for one diagnosis only.

cEEG is profitable for hospitals despite the costs of performing the service

• Contribution Margin:– Allocated net revenue is calculated using total

net revenue for patients receiving these services as a % of the total charges.

• UCLA Contribution Margin– 2005 $402,110– 2006 $ 582, 311

Dissecting the big question of effectiveness into smaller questions

• Effectiveness of a diagnostic test can be defined in many ways– Provides an accurate in diagnosis– Avoids risky testing to rule out other diagnoses– Permits optimal use of treatments and resources– Reduces cost– Improves clinical outcome

Factors that determine outcome

• Primary prognostic factors of the disease– These are not modifiable

• Prompt diagnosis and treatment of complications (seizure)

• Type of complication (seizure-type)

• Side effects of treatment

• End of life considerations