The use of the Pupillometer in predicting increased ICP in the Adult Neurosciences ICU

A case study

Lauren Walker, RN, BSN, CCRN

Case Background On 4/7/11 a 19 year-old-male with no

significant PMH presented to an OSH after the onset of a severe HA.

• At the OSH, the pt became unresponsive, was intubated and sent to CT

•He was then transferred to GUH for a large right intracerebral hematoma

Admission Exam

Neuro: no sedation, no eye opening, R pupil 6mm and nonreactive, L pupil 3mm and sluggish by manual exam, not following commands, MAE non-purposely.

Resp: Intubated, unlabored, clear lung sounds bilaterally, O2 Sats stable.

CV: HR regular, VSS, afebrile, 2+ pulses bilaterally, CRT less than 3 seconds.

Admission Pupil Exam

MD: Right Eye: 6mm and Fixed Left Eye: 3mm Fixed

RN Right Eye: 8mm and Fixed Left Eye: 3mm Sluggish

Why is this admission exam so different when taken at the same time?

Hospital Events 4/7/11: Admitted to NSICU for a Large right side Hematoma

OR for right side craniotomy, hematoma evacuation and EVD placement

Continued to have high ICPs over the next few days despite ICP management and EVD

4/11/11: CT- malignant cerebral edema

4/11/11: OR for Right Craniectomy

4/22/11: Traceostomy

4/25/11: G-Tube Placement

Eventually transferred to an outside facility with a poor neurologic outcome.

Manual pupil exam had different measurements each shift

It took several days and several operations since admission to get stabilized ICPs.

What can we use on the floor for an objective neurologic exam?

The Pupillometer!!!

What does the literature say?

“Performing frequent pupil assessments provides critical and time-sensitive information regarding new or worsening intracranial pathology; therefore, an accurate examination is essential”.

“Automated Pupillometer may be useful in providing ICU nurses with a precise and reliable measurement or pupil size and reactivity.”

Meeker M, Du R, Bacchetti P, Privitera C, Larson M, Holland M, Manley G. (2005). Pupil examination: Validity and clinical utility of an automated pupillometer. Journal of Neuroscience Nursing, 37(1).

Literature Continued

“Using NPi there was an inverse relationship between decreasing pupil reactivity and increasing ICP.”

“Using NPI may be a useful tool in the early management if pts with causes of increased ICP.”

Chen J., Gombart Z., Rogers S., Gardiner S., Cecil S., Bullock R. (2011). Pupillary reactivity as an early indicator of increased intracranial pressure: The introduction of neurologic pupil index. Surgical Neurology International, 2(1), 82-86.

Third Article

“The development of a portable, automated, infrared Pupillometer has recently transformed pupillary parameter measuring from a subjective and highly variable methodology to an accurate and reproducible one”.

“Meticulous standardization of the technique can minimize the observed variations”.

Fountas, K., Kapsalaki, E., Machinis, T., & Boev, A. (2006). Clinical implications of quantitative infrared pupillometry in neurosurgical patients. Neurocritical Care,5

More Literature!

“The pupillometer is a reliable and safe method that provides detailed and accurate information regarding patterns of pupillary responsiveness”.

“Early detection of changes in brain volume with the use of the Pupilometer may reduce the mortality rate”.

Taylor, W., Chen, J., Meltzer, H., Gennarelli, T., Kelbch, C., Knowlton, S., . . . Marshall, L. (2003). Qualtitative pupillometry, a new technology: Normative data and preliminary observations in patients with acute head injury. J Neurosurg, 98, 205-213.

Literature vs C63

Does our patient’s Pupillometer readings correlate with the literature?

Normal Pupillometer Values

Parameter Normal Reportable Condition

% Pupil Change (% Change)

Greater than 10% Less than 10%, a decrease in pupil change is suspicious of intracranial dynamics

Constriction Velocity (CV)

Greater than 0.8 mm/sec

Less than 0.8 mm/sec = an increase in brain volume

Less than 0.6mm/sec correlates with an ICP > 20

NPI Greater than or equal than 3Closer to 5 is more brisk

Less than 3 is a weaker than normal pupil reaction

Other values that are measured:•MIN/MAX aperture

Normal Pupillary Response

C63 Case Study Results (collected by you!)

DAY 1 Data Collection: 4/10/11

1 2 3 4 5 6 7 8 9 100

4

8

12

16

20

24

Figure 1. Right Eye Pupillometer Read-ings. POD 3 Craniotomy, 4/10/11

ICPCV% ChangeNPI

Hours

Readin

g

1 2 3 4 5 6 7 8 9 100

4

8

12

16

20

24

Figure 2. Left Eye Pupillometer Readings, POD 3 Craniotomy, 4/10/11

ICPCV% ChangeNPI

Hours

Readin

g

Sedated on a Propofol gtt (80mg/hr), Fentanyl gtt (500 mcg/hr) Paralyzed on Vecuronium gtt (1.2 mg/hr)

Interventions to decreased ICP also cause an increase in % Change

CV was low in both eyes- especially in left eye indicating ICP. Interventions did not control ICP throughout the day

Pupillometer Measurements vs Manual: 4/10/11, POD 3

RN Documented bilateral pupil response through the day to be 3 and fixed. Pupillometer recorded pupil to be 2.5-3 with a normal reaction to light

4/10/11 Right Eye Max/Min

ICP MAX MIN NPI24 3.04 2.9 319 2.9 2.78 3.117 2.97 2.84 316 2.86 2.73 3.219 2.82 2.59 3.612 2.81 2.59 3.615 2.79 2.54 3.711 2.74 2.49 3.815 2.8 2.51 3.814 2.73 2.49 3.9

4/10/11 Left Eye Max/Min

ICP MAX MIN NPI24 2.49 2.41 3.119 2.65 2.59 3.117 2.59 2.52 3.216 2.6 2.54 3.119 2.55 2.51 3.312 2.56 2.48 3.515 2.63 2.49 3.111 2.54 2.42 3.515 2.59 2.54 3.314 2.58 2.45 3

Day 2 Data Collection 4/11/11

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16048

1216202428323640

Figure 3. Right Eye Pupillometer Reading, POD 4 Craniotomy, POD 0 Hemicrani,

4/11/11.

ICPCV% ChangeNPI

Hours

Readin

gs

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16048

1216202428323640

Figure 4. Left Eye Pupillometer Readings, POD 4 Craniotomy, POD 0 Hemicrani, 4/11/11

ICPCV% ChangeNPI

Hour

Readin

g

↙ Hydrazaline ↑RR

↙ Hydrazaline ↑RR

↙OR: Hemicraniotomy↙OR: Hemicraniotomy

As ICP increases, % change decreases- less than 10 is indicative of IC dynamics

As ICP decreases, % change increase- showing a normal pupil response to light

CV has been low for now for 24 hours- we have objective data that correlates with high ICP and brain damage. How can we use this information to influence decision making at the bedside?Sedated on a Propofol gtt (80mg/hr), Fentanyl gtt (500 mcg/hr)

Paralyzed on Vecuronium gtt (1.2 mg/hr)

Pupillometer Measurement vs Manual: 4/11/11 POD 4, POD 0 Hemicrani

RN Manual Exam: Right and Left Eyes 3 and fixedPupillometer: Right Eye: 2.22-2.8 and brisk, Left Eye: 2.5-2.98 and normal reaction to light

4/11/11 Right Eye Max/MinICP MAX MIN NPI

4 2.8 2.44 437 2.84 2.52 3.917 2.68 2.59 3.214 2.73 2.51 3.7

5 2.62 2.32 4.16 2.67 2.35 4.17 2.59 2.28 4.16 2.6 2.35 3.96 2.63 2.17 4.5

13 2.55 2.2 4.214 2.52 2.19 4.3

9 2.48 2.2 4.212 2.76 2.33 4.212 2.65 2.3 4.212 2.67 2.29 4.212 2.66 2.34 4.1

4/11/11 Left Eye MAX/MINICP MAX MIN NPI

4 2.55 2.46 3.337 2.67 2.61 317 2.6 2.52 3.314 2.66 2.59 3.1

5 2.53 2.25 3.16 2.63 2.53 3.47 2.63 2.58 3.16 2.61 2.51 3.36 2.6 2.44 3.6

13 2.55 2.43 3.514 2.6 2.45 3.6

9 2.58 2.48 3.512 2.63 2.52 3.412 2.6 2.48 3.412 2.68 2.54 3.412 2.98 2.71 3.5

Day 3 Data Collection 4/12/11, POD 5 Craniotomy, POD 1 Hemicrani

Again, we can clearly see the relationship of ICP as it relates to % change in the pupil. There is evidence of left side permanent damage most likely due to pressure displaced

on the ocular motor nerve

1 3 5 7 9 11 13 15 17 19 210

4

8

12

16

Figure 5. Right Eye Pupillometer Read-ings, POD 5 Craniotomy, POD 1 Hemi-

crani, 4/12/11

ICPCV% ChangeNPI

Hours

Readin

g

1 3 5 7 9 11 13 15 17 19 2102468

10121416

Figure 6. Left Eye Pupillometer Readings. POD 5 Craniotomy, POD 1 Hemicrani

4/12/11

ICPCV%Change NPI

Hours

Readin

gs

Sedated on a Propofol gtt (80mg/hr), Fentanyl gtt (500 mcg/hr)

Paralyzed on Vecuronium gtt (1.2 mg/hr)

Manual Exam vs Pupillometer 4/12/11 POD 5

RN Manual Exam: Right: 3.5, briskLeft: 3, sluggish

Pupilometer Exam: Right: 2.5-2.7, briskLeft: 2.5-2.9, normal (but less brisk than right- not sluggish)

4/12/11, POD 5 Right Eye MAX/MIN/NPIICP MAX MIN NPI

12 2.61 2.33 412 2.62 2.26 4.312 2.64 2.33 4.110 2.61 2.27 4.211 2.64 2.24 4.411 2.59 2.35 3.911 2.72 2.36 4.2

9 2.6 2.32 4.19 2.65 2.34 4.1

10 2.54 2.33 3.915 2.63 2.34 4.115 2.67 2.34 410 2.63 2.36 411 2.7 2.44 3.910 2.7 2.45 3.9

9 2.58 2.2 4.310 2.65 2.2 4.413 2.66 2.32 4.113 2.55 2.24 4.112 2.69 2.35 4.112 2.62 2.29 4.1

4/12/11, POD 5 Left Eye MAX/MIN/NPIICP MAX MIN NPI

12 2.69 2.51 3.612 2.66 2.56 3.212 2.64 2.53 3.410 2.65 2.59 3.411 2.65 2.5 3.511 2.65 2.53 3.411 2.61 2.46 3.5

9 2.63 2.53 3.39 2.64 2.58 3.3

10 2.64 2.59 3.315 2.63 2.56 3.215 2.61 2.46 3.510 2.55 2.43 3.311 2.83 2.66 3.410 2.93 2.69 3.6

9 2.6 2.44 3.610 2.82 2.59 3.713 2.65 2.44 3.713 2.59 2.42 3.612 3.37 2.93 3.412 2.9 2.59 3.8

Day 4 Data Collection 4/13/11, POD 6 Craniotomy, POD 2 Hemicrani

As the ICP stabilizes, the % change normalizes as well

1 2 3 4 5 6 7 8 9 10 110

4

8

12

16

20

Figure 7. Right Eye Pupillometer Read-ings. POD 6 Craniotomy, POD 2 Hemi-

crani, 4/13/11.

ICP CV%CHNPI

Hours

Readin

gs

1 2 3 4 5 6 7 8 9 10 110

5

10

15

20

Figure 8. Left Eye Pupillometer Read-ings. POD 6 Craniotomy, POD 2 Hem-

icrani, 4/13/11.

ICPCV% ChangeNPI

Hours

Readin

gs

Sedated on a fentanyl gtt (100 mcg/hr)

Manual Exam vs Pupillometer Exam4/13/11 POD 6

RN Exam: Right- 3 and brisk, Left- 4 and FixedPupillometer Exam: Right- 2.6-2.7 and reactive, Left- 2.99-3.5 and Normal

The nurse did notice that the right eye was smaller and more reactive than the left eye but the left eye was never fixed according to the objective measurement!

4/13/11: POD 6 Right Eye MAX/MIN/NPIICP MAX MIN NPI

10 2.75 2.46 3.913 2.74 2.41 4.111 2.63 2.26 4.3

8 2.66 2.31 4.19 2.59 2.25 4.28 2.57 2.23 4.2

11 2.66 2.31 4.111 2.63 2.33 4.1

8 2.59 2.25 4.210 2.66 2.14 4.5

8 2.68 2.33 4.1

4/13/11: Left Eye MAX/MIN/NPIICP MAX MIN NPI

10 3.31 2.91 3.513 3.12 2.89 3.411 3.1 2.75 3.6

8 3.08 2.77 3.59 3.22 2.78 3.78 3.01 2.72 3.6

11 3.03 2.79 311 3.16 2.87 3.3

8 2.99 2.67 3.710 3.46 2.93 3.5

8 3.41 3.02 3.3

Why use the Pupillometer?

Its Easy!! It’s portable!! It’s user friendly!!

It is a reliable, repetitive, and safe method that provides detailed and accurate information regarding pupillary response!

Non invasive

Policy Patient Selection

Head injury and at high risk for developing increased ICP Acute large hemispheric ischemic stroke ICH Post-op craniotomy Subdural Hematoma Poor grade SAH with aneurysmal rupture Pts with pupil checks only for neuro exam testing

With ICP monitor with ICP < 20 mmHg should have pupils checked with Pupillometer Qshift

ICP readings > 20mmHg should have pupils checked with Pupillometer hourly and after ICP intervention

Pts in barbiturate coma lost pupillary response to light- use Pupillometer Q shift

For the Future…

Should be used for a routine pupil measurement instead of penlight or flashlight

These measurements can help influence the medical decisions of care!

Detect abnormalities faster and help motivate interventions.

Start using it early and use the trends!! Don’t stop taking measurements!

What does this mean to you?

In this case, what could we have done in the management of our patient?

What would you do next time when your notice an unchanging trend in low CV or any other abnormal trend in measurements?

WWYD? (what would you do?)

It is time for your routine pupil assessment.

You notice a decline in GCS. Your pts pupils are now asymmetric. You notice an overall decline in your

pt neuro status Your EVD has a poor waveform, you

believe it is not draining correctly or draining CSF

Pupillometer Limitations

Use of narcotics: Fentanyl decreases bilateral pupillary

reflex dilation Versed/Ativan: Bilateral reduction of CV

Challenging in agitated or confused pts

Pts with opthalmological disease, periorbital or scleral edema

References

Bader, M. K. (2011). Inside the black box: Multimodality monitoring in the neuro trauma patient. Unpublished manuscript.

Chen J., Gombart Z., Rogers S., Gardiner S., Cecil S., Bullock R. (2011). Pupillary reactivity as an early indicator of increased intracranial pressure: The introduction of neurologic pupil index. Surgical Neurology International, 2(1), 82-86.

Fountas, K., Kapsalaki, E., Machinis, T., & Boev, A. (2006). Clinical implications of quantitative infrared pupillometry in neurosurgical patients. Neurocritical Care,5.

Meeker M, Du R, Bacchetti P, Privitera C, Larson M, Holland M, Manley G. (2005). Pupil examination: Validity and clinical utility of an automated pupilometer.Journal of Neuroscience Nursing, 37(1).

Taylor, W., Chen, J., Meltzer, H., Gennarelli, T., Kelbch, C., Knowlton, S., . . . Marshall, L. (2003). Qualtitative pupillometry, a new technology: Normative data and prelimary observations in patients with acute head injury. J Neurosurg, 98, 205-213.