WHAT AND HOW TO MONITOR

Rita RogayahDept. of Pulmonology and Respiratory Medicine

Faculty of Medicine, University of Indonesia

Introduction

O2 transportation from air to tissue required integration of 3 system :

Cardiovascular determine cardiac output and distribution of blood flow

Hematology determine the Hb concentration Respiratory determine the PaO2

If the process is inadequate hypoxia lack of oxygenation Hypoxia cant be measured directly

Hypoxemia lack of O2 in blood (PaO2 less than normal) measure by Pa O2 evaluation

O2 therapy supportive therapy in lung disease to prevent hypoxemia.

Goal of O2 therapy to provide the lowest dose of O2 increase PaO2 > 60 mmHg or O2Sat > 90% (therapeutic dose with minimal toxicity)

PaO2 and SaO2 in normal adult

PaO2(mmg) SaO2 (%)

Normal 97 97Normal range ≥80 >95Hypoxemia <80 <95

Mild 60-79 90-94Moderate 40-59 75-89Severe <40 <75

Hypoxemia lack of O2 in blood (PaO2 less than normal) measure by Pa O2 evaluation

O2 therapy supportive therapy in lung disease to prevent hypoxemia.

Goal of O2 therapy to provide the lowest dose of O2 increase PaO2 > 60 mmHg or O2Sat > 90% (therapeutic dose with minimal toxicity)

Monitoring of O2 supplementation :

1. Noninvasive : - Oxymetry- Capnometry and capnography- Transcutaneous- Physical examination

2. Invasive : blood gas analysis evaluation

Oximetry

Monitoring device that can be apply

continuously before being treated in the

hospital, emergency unit and outpatient

department

Oximetry

Applied two high waveform via pulsed vasculary tissue Arterial pulsasion pletismagnet wave

Amplitude ratio in screen SpO2

Probe is applied in :

- finger

- ear

- nasal

Clinical Indications

1. The need to monitor the adequacy of arterial oxyhaemoglobin saturation

2. The need to quantitate the response of arterial oxyhaemoglobin saturation to therapeutic intervention or a diagnostic procedure

Oximetry

Oximetry is applied : During surgical Post surgery Emergency medicine Sleep study Exercise testing Evaluation of LTOT

Oximetry

In poon periphery perfussion such as

hypotension, hypovolemic and hypotermic

and used of vasocontriction agent nasal

sensor

Oximetry

Limitations :1. Motion artifact2. Frequently moving of extremity3. Chills4. Seizure

Motion artifact compare displayed with that obtained manually or by an electrocardiographic monitor

Lack of signal susceptible to the effect of motion artifact applied - warm towel

- central censor (nasal or ear)

Accuracy of reading oximetry depend on sources of light :- Sunlight- Fluorescent light- Infrared heat lamp - Phototherapy lampTo prevent sensor cover with qauze or towel

Others : nail polish colors dark skin pigmentation

Capnometry and capnography

Capnometry measurement and numeric display of CO2 concentration in alveolar ventilation evaluation and detection of CO2

concentration

Capnography graphic of O2 concentration, the waveform is called capnogram.

Capnogram is to measure PaCO2

Capnography

Graphyc evaluation :

1. To evaluate alveolar ventilation

2. Integration of airway and cardiopulmonary

function

Indication of capnomentry and capnography

Evaluation of the maximum exhaled CO2 concentration (end-tidal CO2) PaCO2 in spontaneously breathing

Evaluation of the maximum exhaled CO2 concentration (end-tidal CO2) PaCO2 in intubated patients being mechanically ventilated

Evaluate the severily of pulmonary disease Evaluate the response of intervention therapy Monitoring the integrity of the ventilator circuit and the

artificial airways

Indication of capnomentry …..

Monitoring the pulmonary blood flow Monitoring the concentration of CO2

when CO2 gas is being therapeutically administered

To ensure tracheal insulation instead of eosophageal

To evaluate the wave of capnography

Transcutaneous

Indicated for neonatal + children

Evaluate the sufficiency of artery oxygenation/ventilation

Evaluate diagnostic response & treatment intervention

Limitation Repeated calibration Changing of electrode position Required time for balancing after electrode

fitting The electrodes temperature effect to

measurement Suboptimal measurement hypoperfusion

area Haemodynamic disturbing underestimate of

PaO2, overestimate of PaCO2

Physical Examination Oxygen treatment : Improves cardiac function Decreases pulmonal hypertention Increases perfusion of vital organ

Hear rate & blood pressure stable Aritmia, cyanosis, tachypnea dismissed Neurologic disturbing dismissed

Artery blood gas analysis

Gold standard

Evaluate gas changing of O2 and CO2 and acid-base state

Blood gas analysis abnormal early sign of oxygenation disturbing or acid-base imbalance

Arterial blood gas value

Blood gas exchange normal value

Partial pressure carbondioxide (PaCO2) 35-45 mmHg

Partial pressure oxygen (PaO2) 80-100 mmHg

Oxygen saturation (SaO2) 95-97%

Concentration ion hydrogen (PH) 7,35-7,45

Ion bicarbonate (HCO3) 22-26 mEq/L

The blood of artery is obtained from:

Radialis artery

Brachialis artery

Femoralis artery

Radialis artery The best source Near the cutaneous surface Easy to be palpated Have the colateral system from ulnaris

artery

Blood gas analysis 15-20 minutes after

oxygen therapy or if there is clinical

worsening performed immediately (as

soon as possible)

Next evaluation

12 hours after giving FiO2 < 40% 8 hours after giving FiO2 > 40% 72 hours for acut myocard infark 2 hours for COPD patient 1 hour for neonatus

CONCLUSION

1. Monitoring of oxygen therapy - Noninvasive - Invasive

2. Monitoring noninvasive- Oximetry- Capnography - Physical examination

3. Monitoring invasiveBlood gas analysis gold standard