CO2 Physiology

What is Carbon Dioxide? Capnos comes from the Greek word for “smoke” smoke from the fire of metabolism a natural waste product of cellular activity CO2 is a compound molecule 1 element of carbon and 2 elements of oxygen colorless and heavier than air green plants clean up after our exhaled CO2

Physiology of CO2 CO2 produced by cellular metabolism diffuses across the cell membrane into the circulating blood. The blood transports the CO2 to the lungs. Then it diffuses from the blood into the lungs. CO2 is eliminated with alveolar ventilation on exhalation.

Physiology of CO2 Carbon Dioxide is transported in the blood in three (3) principle forms: 5 to 10% as gas & reflected by the PCO2 20 to 30% is bound to blood proteins, the major one being hemoglobin 60 to 70% is carried as bicarbonate (HCO3)

Physiology of CO2 About 5-10% of CO2 is eliminate through exhalation only. The rest is recycled in the body through the circulatory and renal systems. The heart and lungs would have to increase their work 10 times if they were required to eliminate all the CO2 the body produces!

Ventilation & EtCO2 Monitoring Endtidal CO2 (EtCO2) is the CO2 measured at the end of expiration. EtCO2 concentration provides a clinical estimate of the PaCO2, if ventilation and perfusion are appropriately matched. EtCO2 monitoring allows for a breath by breath assessment of ventilation.

Capnography— The continuous measurement and graphic display (waveform) of the CO2 concentration in the patient’s airway during the respiratory cycle. Normal waveform:

Respiratory Cycle O2 CO2 CO2 O2

Respiratory Cycle Oxygenation = oxygen → lungs→ alveoli→ blood Monitored by a Pulseoximeter Metabolism = oxygen is converted to energy + CO2 Monitored by a Metabolic Computer Hymodynamic Parameter Monitored by ECG, IPB, NIBP, Temperature Ventilation = CO2 → blood→ lungs→ exhalation Monitored by a Capnograph

The relationship – EtCO2 and PaCO2 Normal conditions: EtCO2 is between 35 – 45 mmHg PaCO2 & EtCO2 will be very close EtCO2 is most 2 - 5 mmHg less with normal physiology Widening of this difference can be caused by: Incomplete alveolar emptying Ventilation-perfusion abnormalities Poor sampling Capnography monitoring of Critically ill patient may alert clinicians to underlying conditions Under normal conditions EtCO2 will nearly match the PaCO2. Usually, the values are within 2 to 5 millimeters of mercury of one another, with the EtCO2 being lower.   It is important to understand that there are abnormal clinical situations, usually metabolic or lung perfusion abnormalities, where these values will widely differ. Because of this, Capnography monitoring in the management of critically ill patients requires awareness of any significant difference between the ETCO2 and the PaCO2 values and the underlying conditions causing the difference. In some patients, knowing that there is an increased gap between ETCO2 and the PaCO2 can help identify clinical problems

PaCO2 vs. EtCO2 PaCO2 – Partial pressure of CO2 present in arteries (similar to concentration) Invasive ABG analysis EtCO2 – concentration of CO2 exhaled in each breath Non-invasive measurement at airway PaCO2, or Partial pressure arterial CO2, reflects the concentration of Carbon Dioxide present in the arteries. This measurement is obtained through ABG, or arterial blood gas analysis. ABG analysis requires a blood sample to be drawn directly from an artery, or from an indwelling arterial catheter.   End tidal CO2 concentration is measured at the end of exhalation. This measurement is performed non-invasively, at the airway.

Normal waveform D A-B: Baseline = no CO2 in breath C-D: Alveolar plateau D D: End expiration (EtCO2) B-C: Rapid rise in CO2 D-E: Inhalation A-B: Baseline = no CO2 in breath There is only one normal waveform: A to B shows the waveform baseline. There should be little or no CO2 B to C shows the rise in CO2 as the dead space ventilation mixes with alveolar gas. This part of ventilation involves the trachea, main stem bronchus and airways.  At C to D the waveform levels off representing the alveolar plateau. This part of ventilation involves mostly alveolar gas.  D is the point at the end of expiration, and just before inspiration, where EtCO2 is measured. The end of the waveform is segment D to E, a rapid, sharp down stroke indicating a drop in CO2 back to zero, and the beginning of inspiration.

Normal waveform - 35-45 mmHg The textbook normal range for end tidal CO2 is from 35 to 45mmHg. However, hospitals may incorporate slightly different normal ranges into their individual protocols. Be sure to check and verify what the accepted normal range is for your institution.   Although the numeric EtCO2 value is important, the waveform, called a capnogram, is the most pertinent information provided by capnography during Sedation, as it will change immediately when there is a change in breathing.

Hypoventilation FIRST, If you administer a dose of Versed and Demerol , the patient will become relaxed. As relaxation progresses, the respiratory rate will decrease, resulting in longer intervals between exhalations. This, in turn, will cause a build up of CO2 in the body and lungs. Therefore, each exhalation will contain a greater quantity of carbon dioxide and EtCO2 readings will rise.   This is textbook HYPOventilation: a decrease in respiratory rate resulting in an increase of end tidal CO2.

Hypoventilation with shallow breathing SECOND, During Sedation, hypoventilation may be exhibited differently if the patient’s breathing becomes more shallow. Shallow breathing often involves such low exhaled volumes that the gas deep inside the lung, “alveolar gas”, may not flow all the way to the mouth to be sampled. Instead, some of the gas in the trachea, called dead space gas, that does not contain CO2 may mix with the alveolar gas and dilute it.   In this scenario, even though blood and alveolar CO2 are elevated, end tidal CO2 will appear to decrease.

Relationship between EtCO2 and RR The last relationship to note is the inverse correlation between EtCO2 and respiratory rate, meaning that when respiratory rate decreases, EtCO2 increases and when respiratory rate increases, the EtCO2 will decrease.   To help understand the basis of this relationship, let’s use a few illustrations: Breath-to-breath measure of ventilatory status

Hyperventilation THIRD, if for some reason your patient had a sudden fright, his or her respiratory rate will probably shoot up. As the respiratory rate increases, there will be shorter intervals between breaths, and therefore less CO2 available in the lungs for exhalation. Consequently, there will be a decreased EtCO2 value.   This is classic HYPERventilation: a high respiratory rate causing a lowered EtCO2 value. You may have experienced a tingling in your finger tips when you are frightened. This can be caused by a sudden drop is CO2!

Some Definitions Capnometer Capnography Teaching Tip: Stress to your audience that often times these terms are used interchangeably, and they do have very different meanings. Presentation Tip: It will also help identify these definitions early so that as you continue your presentation the definitions you use are clear to your audience. Oridion prefers that capnography is the term used to describe the technology

Capnometer A Capnometer provides only a numerical measurement of carbon dioxide in mmHg or kPa or Vol.-% Presentation Tip: You may choose to go back to the previous slide with the monitor and point out the 32 again for those who are not very familiar with CO2 Monitoring.

Capnograpy Capnography provides the CO2 value and the waveform of carbon dioxide over time Teaching Tip: The waveform can help you determine the underlying problem that accompanies that number (if you are comfortable relating the waveforms from a pulmonary artery line and the information it can give you, this may be helpful). The waveform can be seen from breath to breath. Also add that the waveform trend is important to see subtle and/or acute changes (such as a partial disconnection, decreasing cardiac output, etc.)

Capnography— The Ventilation Vital Sign™ Earliest sign that something is going wrong Breath by breath assessment of ventilation

Capnography An EtCO2 value of e.g. 38 mm/Hg without a 5 4 3 2 1 it´s like a heart rate of e.g. 80 without an

CO2 Measurement Technology General: CO2 measurement technology Infrared absorption Technique of airway gas sampling Main stream vs. side stream vs. Microstream

Sampling Technology Mainstream sampling - CO2 analysis chamber is in-line between the patient airway and the ventilator circuit Sidestream sampling - CO2 analysis chamber is within the device. The patient’s expired gas is sucked from the airway and drawn to that chamber through a sampling line.

Conventional main stream technology Monitor Expiration Inspiration Fresh gas

Conventional side stream technology Sample line (Monitor)

Unique solutions for Capnography = Microstream® Presentation Tip: Get your audience to think about uses for Microstream that they had not thought about. Teaching Tip: There are a variety of clinical environments where Microstream Technology is used. Because it can be use for both intubated and non-intubated patients, a patient could be monitored during surgery (while they are intubated), be transported after they are extubated, and then continue monitoring to insure patient safety.

Microstream® CO2 A combination of a unique CO2 sidestream measurement technology and; FilterLine (proprietary sampling lines) - for single patient use Only system providing accurate EtCO2 readings for non-intubated patients that receive supplemental O2 and switch between oral and/or nasal breathing u-StreamCO2-03 Microstream is a unique technology developed by Oridion Medical Ltd., an Israeli company. It’s a special sidestream CO2 implementation, which combines an advanced Infrared Absorption measurement technology and smartly designed so-called FilterLine disposables. The Microstream technology provides the following major benefits: it can be used with both intubated and non-intubated patients it accomodates the full range of patients from neonatal to pediatric and adult it is less susceptible to interference from other gases there’s a complete line of one-piece plug&play accessories is available for all application areas where CO2 is measured an extremely low sample flow rate, hence its name, and because of its performance, may replace mainstreamCO2, considered by some to be the gold standard

Microstream® CO2— Major benefits Ease of Use Reliable Technology Flexible for all patient types Versatile for all environments u-StreamCO2-03 Microstream is a unique technology developed by Oridion Medical Ltd., an Israeli company. It’s a special sidestream CO2 implementation, which combines an advanced Infrared Absorption measurement technology and smartly designed so-called FilterLine disposables. The Microstream technology provides the following major benefits: it can be used with both intubated and non-intubated patients it accomodates the full range of patients from neonatal to pediatric and adult it is less susceptible to interference from other gases there’s a complete line of one-piece plug&play accessories is available for all application areas where CO2 is measured an extremely low sample flow rate, hence its name, and because of its performance, may replace mainstreamCO2, considered by some to be the gold standard

Microstream® advantages Reliable technology Superior moisture handling of liquids, secretions and humidity CO2 specificity – no cross-sensitivity to anesthetic gases Rugged – no moving parts in sensor Long-term monitoring

Microstream® advantages Flexible for all patient populations – solution for monitoring Neonates 50 ml/min flow rate supports entire patient population – including neonates (Competition at 3 – 5 times the flow rate) Does not compete for Neonate tidal volume The lower the flow, the less moisture to be handled u-StreamCO2-06 In contrast to conventional sidestream techniques, Microstream does not compete with the baby’s tidal volume, and thus can be applied with the full range of patient sizes, from neonatal to adult, without switching sample flow rates or manually adjusting tidal volume settings for compensation of sample flow. This is why many customers who were used to Mainstream CO2 with neonates may want to switch to Microstream now. Switching from intubated patients to non-intubated patients for CO2 measurement is as simple as removing a FilterLine Set and connecting a Nasal FilterLine without any adjustment. The same is true for switching from one patient to another one.

Microstream® advantages Ease of use No expensive sensors to replace Yearly calibration – done in 5 minutes Warm up time – 45 seconds from ON until first waveform and number appears One-piece Plug & Play consumables

Microstream® advantages Micro sample cell 15 µL 1 Eurocent Light source Light source housing

Microstream® Core Technology Sensor Housing I.R Source Optic Block (Micro Sample Cell) I.R Detectors

Microstream® advantages Reliable Technology Fast response time 1 mm micro bore tubing reduces delay time Crisp waveform – longitudinal filter maintains laminar flow Build-in water trap – don't clean and re-use any FilterLine – it destroys the inline filter

Microstream® advantages Flexible Both intubated and nonintubated applications Alternating mouth and nose breathing Oxygen delivery (low flow O2 solution; solution for high flow O2 delivery) Adult, pediatric, and neonates

Microstream® advantages Versatile All clinical environments: Critical Care Sedation Procedures EMS/ED Operating Room

Unique solutions for Capnography FilterLine® patient interfaces Presentation Tip: Get your audience to think about uses for Microstream that they had not thought about. Teaching Tip: There are a variety of clinical environments where Microstream Technology is used. Because it can be use for both intubated and non-intubated patients, a patient could be monitored during surgery (while they are intubated), be transported after they are extubated, and then continue monitoring to insure patient safety.

FilterLine® solutions for all applications Non-Intubated FilterLine® Sets Intubated Smart Solutions NIV-Line Smart CapnoLine / Smart CapnoLine O2 CapnoLine H

Smart Solutions for nonintubated patients “Microstream® technology allows the accurate measurement of EtCO2 in the absence of an endotracheal tube.”* Continuous sampling from both mouth and nose Special oral-piece design optimally samples from mouth - Increased surface area provides greater sampling accuracy in the presence of low tidal volume (adult/intermediate size) u-StreamCO2-10a For non-intubated patients, a wide variety of different Microstream accessories is available: A Nasal FilterLine combines a FilterLine sample tube and a nasal cannula. This accessory is available in three sizes: Adult, Pediatric, and Neonatal. [2nd TEXT BLOCK / 2 LOWER PHOTOS] u-StreamCO2-10b A SMART CapnoLine is a Filterline sample tube and a combined oral-nasal cannula. In addition to the nasal prongs, these have a lower extension to sample air exhaled from both the nose and mouth. In this way, an ETCO2 value is obtained that is closer to what would be acquired if the patient were intubated. *ASA 2001 Jay Brodsky, MD Professor of Anesthesia, Stanford University Medical Center, CA USA

Smart Solutions for nonintubated patients Smart CapnoLine™ Plus / Smart CapnoLine™ Plus O2 nasal cannula for CO2 measurement and O2 delivery Uni-junction sampling method ensures optimal waveform and ultra-fast response time Unique O2 delivery method reduces CO2 sampling dilution (up to 5l/min) Solution for high flow O2 delivery (works effectively under oxygen delivery mask) u-StreamCO2-10a For non-intubated patients, a wide variety of different Microstream accessories is available: A Nasal FilterLine combines a FilterLine sample tube and a nasal cannula. This accessory is available in three sizes: Adult, Pediatric, and Neonatal. [2nd TEXT BLOCK / 2 LOWER PHOTOS] u-StreamCO2-10b A SMART CapnoLine is a Filterline sample tube and a combined oral-nasal cannula. In addition to the nasal prongs, these have a lower extension to sample air exhaled from both the nose and mouth. In this way, an ETCO2 value is obtained that is closer to what would be acquired if the patient were intubated.

Solutions for non-intubated patients CapnoLine H*™ / CapnoLine H O2 Enables continuous EtCO2 monitoring in high humidity environments (i.e. ICU) Can be used up to 72 hours Piece of Nafion * = Humidity

Microstream®—A Unique Solution For Non-intubated Patients CO2 sampling / O2 delivery for non-intubated patients (up to 5 L/min.) Small pin holes deliver pillow of oxygen around both nose and mouth Nasal and Oral Sampling Increased surface area provides greater sampling accuracy in the presence of low tidal volume Uni-junction™ of sampling ports prevents dilution from non-breathing source

FilterLine® Sets - Solutions for intubated patients Easily handles moisture and secretions without water traps Able to measure in any position Nafion® tubing allows for long-term monitoring without moisture build up Easily switches to non-intubated monitoring without re-calibration of monitor Low add. dead space (0,4 cc) to use on neonates u-StreamCO2-09 Let’s now have a closer look on the available FilterLine accessories. With intubated patients the following accessories can be used: A “FilterLine Set” is the combination of an airway adapter and a FilterLine sample tube. An Adult version only is available (see upper picture, orange connector). A “FilterLine H Set” is also a combination of airway adapter and sample tube, however in this instance it is the special FILTERLINE “H” sample tube for high humidity applications. There are 2 sizes available: one for Adult/Pediatric, the other for Infant/Neonatal. To repeat, the special H Filterline tubing has yellow connectors, as you see here.

FilterLine® recommendations: Sedation Areas; GI Lab, Cath Lab, EP Lab

FilterLine® information to avoid problems Do not try to dry the FilterLine® - this will damage the filter Ensure there are no kinks in the sampling line Do not cut the oral flange on the Smart CapnoLine Do not cover the Nafion® Do not instill medications through the airway adapter Never pass a suction catheter or stylus through the airway adapter Change the FilterLine® or the Set if a “Blockage” message appears on the monitor screen or if the readings become extremely erratic u-StreamCO2-09 Let’s now have a closer look on the available FilterLine accessories. With intubated patients the following accessories can be used: A “FilterLine Set” is the combination of an airway adapter and a FilterLine sample tube. An Adult version only is available (see upper picture, orange connector). A “FilterLine H Set” is also a combination of airway adapter and sample tube, however in this instance it is the special FILTERLINE “H” sample tube for high humidity applications. There are 2 sizes available: one for Adult/Pediatric, the other for Infant/Neonatal. To repeat, the special H Filterline tubing has yellow connectors, as you see here.

FilterLine® answers for the most FAQ´s: Latex free Single-patient use Not sterile u-StreamCO2-09 Let’s now have a closer look on the available FilterLine accessories. With intubated patients the following accessories can be used: A “FilterLine Set” is the combination of an airway adapter and a FilterLine sample tube. An Adult version only is available (see upper picture, orange connector). A “FilterLine H Set” is also a combination of airway adapter and sample tube, however in this instance it is the special FILTERLINE “H” sample tube for high humidity applications. There are 2 sizes available: one for Adult/Pediatric, the other for Infant/Neonatal. To repeat, the special H Filterline tubing has yellow connectors, as you see here.

Sedation Procedures “Monitoring of exhaled carbon dioxide should be considered for all patients receiving deep sedation and for patients whose ventilation cannot be directly observed during moderate sedation.”* *Practice Guidelines for Sedation and Analgesia by Non-Anesthesiologists, Developed by the American Society of Anesthesiologists Task Force on Sedation and Analgesia by Non Anesthesiologists: Anesthesiology 2002; 96:1004

Microstream® solutions during Sedation Procedures Benefits and Uses Assesses - patent airway (airway obstruction) protective reflexes response to verbal/physical stimuli Respiratory changes can immediately be assessed Microstream® allows for continuous respiratory monitoring with no nuisance alarms in procedural sedation environments where currently there is minimal usage of monitoring Presentation Tip: The next series of slides are self-explanatory. Again, stress the current standards as well as the various societies definitions of conscious sedation.

Microstream® solutions during Sedation Procedures Cardiac Cath. Lab GI lab Pulmonary lab Emergency Department Hyperbaric medicine Dental Clinics Radiology Applications

Moderate – procedural sedation Moderate sedation has been called “conscious” sedation for many years and now is also being referred to as ‘procedural’ sedation.

Capnography and sedation How can capnography make a difference in how you care for the sedated patient? What you do will not change When you do it will! Early detection of potential patient compromise Now that we understand the basics of capnography, let’s look at how we can incorporate this parameter into managing patients undergoing sedation.   At this point, we want to emphasize that capnography is not going to change what you do for your patients; it will only change when you do it. The goal is to provide you with better, more timely information so that you can intervene at the earliest sign of potential patient compromise.

Protocol during procedural sedation Baseline Ventilatory Assessment E.g. after 12 hours NPO (nothing by mouth) = EtCO2 Know the respiratory rate, waveform, and EtCO2 numeric value before drug administration Continuous monitoring throughout case and recovery RR, ETCO2 value…changes from baseline (trends) Changes in the Waveform…Earliest indicator of potential problems. (size, shape) When using Capnography During Sedation, the emphasis is on significant changes from the baseline waveform and/or numeric EtCO2 value, rather than absolute numbers.   For instance, if a patient goes 12 hours without eating prior to the procedure, metabolism slows and less CO2 is produced. The baseline EtCO2 value will likely be lower than what would be considered normal range. Therefore, a low EtCO2 value is normal for this patient, at this time. Before sedating the patient, a baseline assessment should be recorded, noting the Respiratory Rate, and EtCO2 values, along with visualization and description of the waveform. Throughout the procedure, document, along with other vital signs, the respiratory rate, EtCO2 value and the waveform shape, noting any significant changes in shape and/or size. Remember: The waveform will be the FIRST indication of airway compromise which allows for early intervention. Early intervention

Changes from baseline Change in EtCO2 value > 10 mmHg Significant waveform change Becomes erratic Flatlines Common changes from baseline during sedation which require intervention include: a change in the numerical EtCO2 of greater than 10 millimeters of mercury, or, a waveform that suddenly becomes erratic in shape and size, or flatlines.

Changes from baseline - action Remember the ABC’s (airway, breathing, circulation) Assess the patient Follow your normal protocol, which may include: Ensure open airway Stimulate patient if necessary Check the cannula positioning Stop drug delivery Inform M.D. / pause procedure if necessary Administer reversal agents as prescribed With any significant change, no matter what it is, your first action will always be the same: Assess your patient.   After assessing the patient, follow your hospital’s protocol, which may include 1. Ensure open airway 2. Provide gentle stimulation if the patient does not respond 3. Check the cannula and re-position for better sampling Often, with prompt intervention, these simple actions will alleviate the problem. In some cases, you may also need to: ·         Stop drug delivery Inform the physician and pause the procedure if necessary Administer reversal agents as directed

Deep sedation Inadequate respiratory effort to clear dead space Requires higher vigilance in ventilatory monitoring Maintain patent airway Potential dead space ventilation Chest moves up and down Inadequate respiratory effort to clear dead space Deep sedation requires higher vigilance in ventilatory monitoring, as the patient may need assistance to maintain a patent airway. Also, spontaneous breathing may not be adequate to clear dead space. In this case, although the chest is moving up and down, it does not confirm adequate ventilation because the patient is only moving dead space air in and out of the airway, not in and out of the lungs.

Assessing for changes from baseline In addition to the abnormal waveforms to be discussed, it is important to note that significant events can be more subtle in their waveform display:   First, when a patient is sedated, shallow breathing often occurs. The expected gradual increasing of the EtCO2 value, and associated waveform, may not be seen immediately. What you may see frequently, upon sedation, is that the EtCO2 value will decrease and the waveform becomes smaller, due to the shallow respirations. When the patient finally does take a deep breath - and full gas exchange takes place - that is when you will see an increase in EtCO2 value along with an increase in the height of the Waveform Hypoventilation with shallow respirations

Nursing interventions Continue to monitor Ask patient to take a deep breath An appropriate action to this observation is to continue to monitor the patient’s airway and periodically ask the patient to take a deep breath.

Abnormal waveforms Absent alveolar plateau indicates incomplete alveolar emptying or loss of airway integrity Possible causes Partial airway obstruction caused by: Tongue Position of head A degraded waveform with the loss of alveolar plateau is an indication of incomplete alveolar emptying, often caused by partial airway obstruction. Two common causes of airway obstruction are: relaxation of the throat muscles, causing the tongue to obstruct the airway, or a head position that obstructs air flow.

Assessing for changes from baseline Rebreathing often results from: Poor head and neck alignment Draping near the airway Shallow breathing – not clearing dead space The second observation to note is if the waveform does not return to the baseline, or zero. This could mean that the patient is re-breathing of CO2. During sedation, re-breathing can be caused by poor head and neck alignment, by draping near the airway, or, sometimes, very shallow breathing where the breath is not deep enough to clear the dead space.

Assessing for changes from baseline Dead space ventilation Chest movement Little – to no air movement in and out of lungs Another very important, but very subtle observation is when the respiratory effort involves only the very early part of exhalation, this is called dead space ventilation. Although, there may still be chest movement, there will be little to no air movement in and out of the lungs

Abnormal waveforms Absent alveolar plateau indicates incomplete alveolar emptying or loss of airway integrity Possible causes Partial airway obstruction caused by: Tongue Position of head A degraded waveform with the loss of alveolar plateau is an indication of incomplete alveolar emptying, often caused by partial airway obstruction. Two common causes of airway obstruction are: relaxation of the throat muscles, causing the tongue to obstruct the airway, or a head position that obstructs air flow.

Nursing interventions Assess patient Ask patient to take a deep breath Adjust patient’s head position, if necessary Adjust cannula position, if necessary As with any time there is a significant change in the waveform, always look at your patient FIRST. Actions may include one, or all of the following: You may ask the patient to “take a deep breath”, or simply adjust the patient’s head to alleviate the problem. OR you may need to adjust the cannula position.

Putting it all together The transition from conscious sedation to unconscious/anesthesia is very subtle and can be undetected until oxygenation is impaired You must be prepared to monitor a patient at a level deeper than intended “Respiratory frequency and adequacy of pulmonary ventilation are continually monitored” Only capnography provides an immediate notification of a ventilatory event We can see that levels of sedation occur on a continuum. Because the transition from moderate to deep sedation is very subtle and oxygenation is a late indication of ventilatory problems, you must be prepared to monitor the patient at a level deeper than that intended.   The only monitoring that can accurately reflect respiratory frequency and adequacy of pulmonary ventilation is continuous capnography. Capnography provides immediate information about an airway obstruction, hypoventilation or a total cessation of breathing. Continuous capnography monitoring adds an additional level of patient safety during sedation and provides you, the caregiver, with vital information with which to make accurate assessments and timely interventions for your patient.