AND HOW NOT TO GET USED BY THEM….

The Tools we use

RULE No. 1

Tools supplement clinical thinking and details subjective and objective assessments, they do not replace them.

AKA: Treat the patient, NOT THE MONITOR (or the glucometer, or the pulse ox…)

RULE No. 2

Tools fail if you: Don’t take care of them Don’t check them out EVERY SHIFT Don’t know how to use them Don’t know how to NOT use them Don’t read about the technology behind them…

AKA: Murphy is a son of a bitch waiting to screw with you and your equipment….

What we will cover…

StethoscopeSphygmomanometerGlucometerSPO2/SPCOEKGETCO2

Stethoscope

Stethoscope

Prior to the advent of the stethoscope, there were no reliable, non-invasive (and therefore non-lethal) methods to assess certain parts of the human anatomy.

A Stethoscope is used by Auscultation (listening) Sound is simply interpretation of vibrations by the

specialized nervous system structures that send data to the brain.

Therefore any method that limits outside vibration and noise will increase the fidelity of auscultation… Position to the patent Length and thickness of tubing on stethoscope Heels off ground in moving ambulance Environmental factors

Auscultation

Auscultation

1 1

2 23 3

A4 4

5 5

6 6

H

Variations

ElectronicRecordingDuo-stethascope (for

teaching)Fetoscope, AKA A

Pinard Horn

Sphygmomanometer

Rev. Stephen Hale's experiments to determine the blood pressure of a horse. Circa 1733

Sphygmomanometer

When we talk about blood pressure, we are usually speaking of Non-Invasive Blood Pressure (NIBP).

This is used to estimate the Mean Arterial Pressure (MAP) and thus estimate Aortic Pressure.

Key Point: Blood Pressure (NIBP) is an indirect estimate of central

perfusion pressures

Blood Pressure (NIBP)

Two basic types Manual

Mercury Aneroid

Automatic

Blood Pressure (NIBP)

Systolic Diastolic Mm HgPulse pressureMAP

Blood PressureMeasure of pressure against SYSTEMIC vessel walls Systolic

Pressure created in the arteries Reported first

Diastolic Left ventricle relaxed and refilling Reported second

Pulse Pressure

Generally speaking it is the pressure that produces a pulse that we can feel.

Specifically it is pulse pressure is calculated by subtracting the diastolic pressure from the systolic pressure. SBP – DPB = Pulse Pressure

Significant for: A PP is considered LOW if it is less than 25% of the SBP. A narrowing PP is significant for progressing cardiac

tapenade, blood loss, or Tension Pneumothorax A high PP is significant for cardiac disease, HTN, and cor

pulmonale

Korotkoff Sounds in Blood Pressure Korotkoff sounds

Sounds heard during auscultation of the blood pressure Caused by the jetting of blood through the collapsed

artery. Systolic pressure: the first sounds as blood is pushed

through an artificially constricted artery covered by the BP cuff

Diastolic pressure: the point at which blood flow is no longer forced through the constricted artery (i.e pressure is no longer great enough to collapse the artery).

Blood PressureStroke Volume (SV) x heart Rate (HR) =

Cardiac Output (CO)

Cardiac Output (CO) x Systemic Vascular Resistance (SVR) = Blood Pressure

So B/P is the result of the “Pump” and the

“Tank”, and partly the “Volume”

Mean Arterial Pressure

The MAP is an mathmatical estimate of the current perfusion pressure. A minimum MAP of 50-60 mmHg is needed for most perfusion

sensitive organs. Two main methods of calculation:Diastolic pressure + one third of the patients pulse

pressure: diastolic blood pressure + (pulse pressure/3).

Diastolic pressure times 2 plus the systolic pressure and then divide that number by 3: (diastolic pressure x 2) + systolic pressure] / 3

“Normal MAP” is between 70—110 mmHg A normal MAP does not preclude a serious condition

Q: What is the 80-70-60 rule for blood pressure?

Q: Is it accurate?

The 80-70-60 rule ?

The minimum blood pressure pre dicted by the guidelines was exceeded in only four of 20 patients.

The mean blood pressure and reference range obtained for each group indicate that the guidelines overestimate the systolic blood pressure associated with the number of pulses present.

Orthostatic Blood Pressure

Procedure:Assess the need for orthostatics.Obtain patient’s pulse and blood pressure while supine.Have the patient sit up for one minute; Obtain the patient's blood pressure and pulse while

sitting. If positive orthostatic changes occur while sitting, DO NOT continue

to the standing position. Have patient stand for one minute.

Free standing, not leaning. Obtain patient’s pulse and blood pressure while

standing. Have someone stand on each side of the patient in case of

orthostatic syncope

Orthostatic Blood Pressure

Orthostatics are considered POSITIVE if: The patient was unable to tolerate standing and became severely

symptomatic. If pulse has increased by 20 BPM OR systolic blood pressure

decreased by 20 mmHg, the orthostatics are considered positive. As an alternative, an increase of 10 BPM AND a decrease of 10

mmHg may also be considered positive if symptomatic. Document the time and vital signs for supine and

standing positions on/with the patient care report (PCR).KEY Points:

You need both PULSE and BLOOD PRESSURE You need the patient to be in each position for a full minute. If they cant complete the test, it is considered positive.

Monitoring Blood Glucose

Source: Accu-Chek® Aviva used with permission of Roche Diagnostics.

Blood glucose monitoring kit

Monitoring Blood Glucose

Perhaps the single most important factor in a diabetics health is how well they monitor their own BG.

Severity of diabetic complications depends on patient’s average blood glucose level.

Glucose Monitors Facts

Personal use: Calibrated Monthly (rare)For EMS use: Calibrated WEEKLYMost have a chip which need to be changed

with EVRY BOTTLE OF NEW STRIPS Affected by tempAffected by time (samples must be applied

w/in 30 –60 seconds)

Blood Glucose Monitoring

Should be done daily or more often.When done by EMS, should be done in the

opposite ext. as D50 was given.Venous blood usually runs about 10 mg/dl

higher than capillary blood.

Checking the Blood Glucose Level (BG)

Glucometers are commonly found on EMS units.

Determines the amount of glucose in the blood, the sample usually coming from a finger stick.

Glucose is measured in milligrams per deciliter (mg/dl).

A normal range is 80-120 mg/dl. Hypoglycemia is a BGL <60 mg/dl. Hyperglycemia is a BGL >150 mg/dl.

Typically not significant until greater than 250. Often not symptomatic until greater than 400 (not always true)

What are the numbers?

Low: <60mg/dl (<3.0 mmol/L)Normal: 60-150mg/dl (3.0-8.0 mmol/L)

Some recommend 120 mg/dlHyperglycemic: >150 (>8.0 mmol/L)DKA usually seen at 250-500mg/dl

mmol/L vs. mg/dl

What is an MMOL?It is a unit of measurement commonly used in

chemistry based on the molecular weight of the substance it pertains to.

To convert mmol/l of glucose to mg/dl, multiply by 18. To convert mg/dl of glucose to mmol/l, divide by 18 or multiply by 0.055.

SPO2

Pulse oximetry is a non-invasive method allowing the monitoring of the saturation of a patient's hemoglobin.

Originally invented in the 1930’s, it expaded into Ors in the 1980;s, and ER,s ICU’s, and EMS Units in the early 1990’s. Early models were unreliable.

Current technology is not only reliable, but leading into other assessment parameters , including SPCO, SPMet, and Fluid hydration status. There are still things that can “Spoof” common SPO2

devices.

SPO2

It shines infrared light across the blood flow in the capillary beds. The sensor then reads the light reflected back. The color of the light is representative of the state of the hemoglobin (hgb) that is bound up with O2.

Each hemoglobin molecule can be bound (carry) by up to four oxygen molecules.

The SPO2 is an expression of the percentage (%) of hemoglobin that is bound.

SPO2

SPO2 is always expressed as a percentage.By contrast, PAO2 (arterial pressure of

oxygen) is NOT expressed as a percentage. Even though the normal PAO2 is 80-100 mmhg it can

be over 400 mmhg.

SPO2

In Order to have a reliable reading, you must have: A good site to sample Adequate perfusion to that site Appropriate sensor A visible waveform to assess quality of reading

SPO2 Spoofs

CO PoisoningCyanide PoisoningHypothermiaLow perfusion statesShockNail PolishHigh Light situationsPoor Placement

KEY POINT

Pulse oximetry measures solely hemoglobin saturation, not ventilation, not perfusion, not inspired FIO2, and not physiologic stress.

SPO2 WORKS BEST when combined with other monitoring tools, such as the EKG and especially ETCO2

Hyperoxemia

New discussions on the use of SPO2 to detect and prevent hyperoxemia often “get it wrong”.

Hyperoxemia is PAO2 in excess of 100 mmHgSPO2 parameters (controversial and

debatable) 94% SPO2 -> give O2 94%-99% SPO2 -> give supplemental O2 only if in

distress. 99-100% SPO2-> consider withholding O2 or titrating

down O2 unless in severe failure

SPCO

CO-Oxometry is the non-invasive measurement of Carbon Monoxide (CO) in the capillary beds.

It is a developmental evolution from SPO2 technology, originally designed for “low flow” states in neonates.

The current technology most commonly in use is the RAD series from masimo.

The Rad Series

Benefits

Uses “Signal Extraction technology” (AKA SET)

This new generation can be potentially used for SPO2, SPCO2, SpHg and SPMET.

SET technology was originally developed to be a “low perfusion state” and “Motion resistant” SPO2, whose technology was expanded to CO-Oxometry

Early device specific research papers focused on neonates, alternative sensing locations, and anesthesia settings.

RAD-57 Operation: Sensor Placement

SENSOR PLACEMENT IS VERY IMPORTANT When possible, use ring

finger, non-dominant hand.

Insert finger until the tip of finger hits the STOP Block.

Sensor should not rotate or shift freely on finger.

LED’s (red light) should pass through mid-nail, not cuticle.

There is a top and bottom, cable should be on top (nail side).

Optimal LED path

Carbon Monoxide: Suggested Triage Algorithm

Measure SpCO

0-3% >3%

No further medical evaluation of SpCO

needed

Loss of consciousness or neurological

impairment or SpCO >25%

Yes No

Transport on 100% oxygen for ED

evaluation. Consider transport to hospital

with hyperbaric chamber

SpCO >12 SpCO <12

Transport on 100% oxygen for ED

evaluationSymptoms of CO

exposure?

Transport on 100% oxygen for ED

evaluation

No further evaluation of SpCO needed.

Determine source of CO if nonsmoker

Yes No

SpCO TRIAGE ALGORITHM

How its being used in EMS nationally

Asymptomatic patients – Screening when there is a CO alarm, Hx of

potential exposure, or for rehab situations Asymptomatic Patients with elevated readings

may be screened and reevaluated after 15 minutes of High Flow O2 and Medical Control Consult

Asymptomatic patients without elevated levels may be released on scene. (Controversial)

Symptomatic patients Transport all symptomatic patients

REGARDLESS OF SPCO Screening for severity and diversion to HBO

(Hyperbaric therapy)

SPCO

When used correctly : It is accurate within +/-2% of carboxy-hemoglobin levels to measure CO (the accepted standard)

When not used correctly: It is useless and provide false reassurance.

Downfalls

Very sensitive, can be “spoofed” by strobes and high ambient light. Cover the probe when “Zero”-ing to the patient

Approx. $4,000 retail

Controversy

There is some debate on the accuracy of the technology. Operator error, high light environments, lack of

understanding of the technology all contribute to a high false positive and false negative rate.

Smokers, urban dwellers, and certain occupations have a naturally elevated baseline. Their “Norm” may be in otherwise “elevated CO” ranges.

WHEN WE GET BACK WE WILL BE ON THE ETCO2 PRESENTATION….

Take a Break