invos_system_inservice_guide_for_neonatal_use.pdf
Page 1
INVOS™
System Inservice Guide
for Neonatal Use
1
INVOS System Inservice Guide for Neonatal Use
Page 2
Key Terms
rSO2: Regional oxygen saturation
INVOS™: In Vivo Optical Spectroscopy
Cerebral Application: Brain area measurement
Somatic Application: Tissue area of measurement
2
INVOS System Inservice Guide for Neonatal Use
Page 3
Regional Oximetry vs. Other Oximetry
Regional (Capillary) Oximetry (rSO2) Clinical Characteristics
• Noninvasive
• Capillary (venous and arterial) sample
• Measures the balance between O2 supply and demand
beneath the sensor
• End-organ oxygenation and perfusion
• Requires neither pulsatility nor blood flow
•
•
•
•
•
Pulse (Arterial) Oximetry (SpO2) Clinical Characteristics
Noninvasive
Arterial sample
Measures O2 supply in the periphery
Systemic oxygenation
Requires pulsatility and blood flow
•
•
•
•
•
Central (Venous) Oximetry (SvO2) Clinical Characteristics
Invasive
Venous sample
Measures O2 surplus in central circulation
Systemic oxygen reserve
Requires blood flow*
Distal Detector
Proximal Detector
LED Emitter
The INVOS™ System uses two depths of light
penetration to subtract out surface data, resulting
in a regional oxygenation value for deeper tissues.
INVOS System Inservice Guide for Neonatal Use
3
Page 4
The Cerebral-Somatic Relationship1-3
The INVOS™ System provides perfusion data from vascular
beds that represent opposite poles of regional circulation and
have different extraction ratios.
Cerebral
• High-flow, high-extraction organ
• Compensatory mechanisms
- Autoregulation
- Flow-metabolism coupling
• Cerebral desaturations are a late indicator of shock if cerebral
autoregulation is intact
Somatic
• Variable flow, lower O2 extraction
• Flow is highly influenced by autonomic (sympathetic) tone
• Somatic desaturations may be an early indicator of shock
(i.e., peripheral circulation is shutting down to preserve
the brain)
4
INVOS System Inservice Guide for Neonatal Use
Page 5
In neonates, infants and children, cerebral and somatic
rSO2 provide noninvasive indications of oxygen changes in
the cerebral and peripheral circulatory systems and may
provide an early indication of oxygen deficits associated
with impending shock states and anaerobiosis.4
rSO2 Reflects Oxygen Balance
rSO2 = Regional Oxygen Saturation
• Increases with rise in delivery or fall in demand
• Decreases when delivery falls or if there is an uncompensated
rise in demand
Oxygen Delivery/Supply Influenced by:
• Oxygen content
- Hemoglobin concentration
- Hemoglobin saturation
• Cardiac output
- Optimize heart rate
- Idealize preload
- Improve contractility
- Manipulate afterload
•
•
•
•
•
•
Oxygen Demand/Consumption Increased by:
Fever, shivering
Malignancy, severe infection
Cold stress
Seizures, status epilepticus
Wounds and burns
Pain
Decreased by:
• Hypothermia, without shivering
• Sedation and paralysis
• Shunting or decreased extraction
INVOS System Inservice Guide for Neonatal Use
5
Page 6
Interpreting the Numbers
Premature or medically challenged neonates face a variety of
physiologic conditions that can threaten adequate cerebral
and tissue perfusion. rSO2 values reflect these patient-specific
comorbidities as well as other variables such as circulating
blood volume, cardiac function, peripheral vascular
resistance, muscular activity, circulating hormones and
venous pressure.
As such, there is no “one number” to act on. Instead each
patient serves as his/her own control based upon an rSO2
baseline set at the outset of monitoring. The monitor displays
rSO2 in two ways: a real-time rSO2 number and as a percent
change from baseline. Clinicians may use either number
to enhance their patient assessment, decision making and
interventions.
Following are the most recognized rSO2 values published on
pediatric patients – most often congenital heart neonates that
have been sent for surgery and then recovery in the pediatric
ICU. Patients with other diagnoses and comorbidities may
differ from this.
Cerebral — High blood flow, high O2 extraction
• Typical rSO2 range: 60-80; assuming SpO2 is >90
• Common intervention trigger: rSO2 <50 or 20%
change from rSO2 baseline
• Critical threshold: rSO2 <45 or 25% change from
rSO2 baseline
Somatic — Variable blood flow, lower O2 extraction
• Variances in the cerebral-somatic relationship may be
indicative of pathology
• Watch for drops of 20% below patient baseline
6
INVOS System Inservice Guide for Neonatal Use
Page 7
The balance of perfusion distribution in premature
neonates depends on gestational age, day of life and
comorbidities. Simultaneous cerebral/somatic rSO2
monitoring can help guide
caregivers in balancing
cardiac performance
and peripheral perfusion
to avoid no- and lowflow states associated
with shock and other
complications.
Interventions
Rises and falls in rSO2
from the patient’s baseline
are an opportunity to
intervene. The care
team should follow its
hospital’s intervention
protocols for restoring
adequate perfusion. These
may include efforts to improve cerebral and somatic
perfusion through a variety of methods such as:
Improve cerebral perfusion by:
• Increasing cerebral perfusion pressure
• Increasing arterial oxygen content
• Reducing cerebral metabolic rate
•
•
•
•
•
Improve somatic perfusion by:
Increasing total cardiac output
Reducing sympathetic outflow
Increasing hematocrit
Maintaining normal temperature
Considering regional vasodilation in shock
INVOS System Inservice Guide for Neonatal Use
7
Page 8
Setup and Baselines
• Plug the sensor cable(s) into the preamplifier(s) connector
(Figure 1). When two somatic site sensors are placed, they
must be connected into the same preamplifier. Secure the
sensor cable to a fixed object to avoid strain on the sensorto-skin interface using strain-relief clips. Ensure the cable
is properly inserted into the preamplifier. Sensor cable can
be connected before or after placement. Different INVOS™
System sensors (adult, pediatric and infant/neonatal) cannot
be used on the same monitor (Figure 2).
• Turn power ON by selecting the green
ON/OFF key. The
INVOS™ System performs a 10-second self-test, stopping at
the Start Screen.
• Press NEW PATIENT. Monitoring begins with display of the
patient’s rSO2 values in white.
• When the patient’s rSO2 values have been displayed for
approximately 1 minute, set a baseline. For all channels, press
the BASELINE MENU button followed by pressing SET
BASELINE.
Status messages on the INVOS™ System display will appear if
monitoring conditions are compromised. Periodically check
skin integrity according to your institution’s patient care
protocol or at least every 24 hours.
For extended monitoring, if adhesive is inadequate to seal
the sensor to the skin, apply a new sensor.
When removing sensors, start at the distal tab and slowly
and carefully peel back while placing fingers on the exposed
skin. Based on your institution’s guidelines, warm water,
petrolatum or commercial adhesive removal solutions may
be helpful.
For complete instructions, warnings and
precautions, see the Operations Manual and
Instructions for Use inside sensor carton.
8
INVOS System Inservice Guide for Neonatal Use
Page 9
Figure 1 - INVOS™ 5100C System Connections
Adult
Pediatric
SomaSensor™ SomaSensor™
Infant/Neonatal
OxyAlert™ NIRSensor
Figure 2 - Sensors
Patient Preparation
To achieve optimum adhesion, the patient’s skin must be
clean and dry. Dry skin with a gauze pad. Warm the sensor in
your hands or an incubator to ease placement.
INVOS System Inservice Guide for Neonatal Use
9
Page 10
Sensor Placement
With white liner facing up, gently bend center of sensor
upward until ends of liner lift away from the sensor’s surface.
Peel off each side, being careful not to touch the adhesive
surface. Apply to the skin. Continue applying the sensor by
smoothing it to the skin from the center outward. Ensure
edges of the sensor are sealed.
Site Selection
To help preserve skin integrity, do not place on undeveloped
skin and do not apply pressure (e.g., headbands, wraps, tape)
to sensor.
Cerebral
Select sensor site on the right or left side of forehead.
Placement of the sensor in other cerebral locations, or over
hair, may cause inaccurate readings, erratic readings or no
readings at all. Do not place the sensor over nevi, sinus
cavities, the superior sagittal sinus, subdural or epidural
hematomas or other anomalies such as arteriovenous
malformations, as this may cause readings that are not
reflective of brain tissue or no readings at all.
Somatic
Select sensor site over tissue area of interest (site selection will
determine which body region is monitored). Avoid placing
the sensor over fatty deposits, hair or bony protuberances. Do
not place the sensor over nevi, hematomas or broken skin, as
this may cause readings that are not reflective of tissue or no
readings at all. Sensor location is at the clinician’s discretion,
provided it adheres to the criteria noted on this Instruction
For Use. Placements may include:
- Posterior flank (T10-L2,
right or left of midline)
- Abdomen
- Forearm
10
-
Calf
Upper arm
Chest
Upper leg
INVOS System Inservice Guide for Neonatal Use
Page 11
Case Graphs
Following are case graphs to help demonstrate the clinical
utility of the INVOS™ System. The sample cases shown
here reflect use of the device as indicated; more patient
populations and applications exist.
Reversal of Shock5
rSO 2: Regional Oxygen Saturation
Sedation/Intubation
VSS, but tissue
perfusion low
Blood transfusion
Inotropes given
Cerebral rSO2
Perirenal rSO 2
Fluids given
Time
Alterations in Ventilation Support in RDS6
CO 2 68 on ABG
100
Switched from
HFOV to HFJV due to over
expansion on X-ray
rSO 2 : Regional Oxygen Saturation
90
80
70
60
ETT suctioned
50
40
30
20
10
Dose two of indomethacin
given for PDA
Isolette changed
0
Dopamine started @ 2 mcg/kg/min
Cerebral rSO 2
Somatic / Perirenal rSO
2
0:00 1:01 2:01 3:02 4:02 5:03 6:04 7:04 8:05 9:05 10:07 11:06 12:07 13:07 14:07 15:06 16:05 17:04 18:03 19:02 20:01 21:00 21:59 22:59 23:58
Time
INVOS System Inservice Guide for Neonatal Use
11
Page 12
References
1. Clavijo-Alvarez JA, Sims CA, Pinsky MR, Puyana JC. Monitoring skeletal muscle and
subcutaneous tissue acid-base status and oxygenation during hemorrhagic shock and
resuscitation. Shock. 2005;24(3):270-275.
2. Fries M, Weil MH, Sun S, et al. Increases in tissue Pco2 during circulatory shock reflect
selective decreases in capillary blood flow. Crit Care Med. 2006;34(2):446-452.
3. Hoffman GM, Ghanayem NS, Tweddell JS. Noninvasive assessment of cardiac output.
Semin Thorac Cardiovasc Surg Pediatr Card Surg Annu. 2005:12-21.
4. FDA 510(k) #K082327
5. Underlying data and case notes on file ISC-10001.
6. Underlying data and case notes on file ISC-10023.
COVIDIEN, COVIDIEN with logo, Covidien logo and
positive results for life are U.S. and internationally
registered trademarks of Covidien AG. Other
brands are trademarks of a Covidien company.
©2011 Covidien. All rights reserved.
11-PM-0259 MN21210
6135 Gunbarrel Avenue
Boulder, CO
80301
800-635-5267
12
www.covidien.com
www.somanetics.com
INVOS System Inservice Guide for Neonatal Use