MONITORINGPulse OximeterECGBlood PressureArterial Pressure

PULSE OXIMETER

Pulse Oximeter’s have created economical, compact, non-invasive and efficient methods of monitoring both pulse rate and oxygen saturation in the patient.

How is it Used?• Connected to the patient via a small lead,

attaching to a probe usually to the index finger or ear lobe.

Pulse Oximeter

How does it work?

• Oxygenated haemoglobin and deoxygenated haemoglobin have different absorbable colours at different light wavelength.

• Comparison of absorbencies at different wavelengths leads to an estimation of relative concentrations of oxygenated and oxygenated haemoglobin

• Non-invasive and work regardless of skin pigmentation

• Provides an overall assessment of the oxygen being delivered to the patients internal and external respiration mechanisms throughout procedures

Problems?

• Been reports of burns, particularly with the prolonged use of finger probes on children

• The readings can be inaccurate. Inaccurate readings may result due to nail varnish or colouring is present, and if venous congestion occurs

ECG Monitoring

What is it used for?Shows the heart rhythm Enables us to read the electrical impulses of the

heartGives Heart rateCan indicate myocardial Ischaemia (Shields &

Werder, 2002)

How is it done?Usually performed when patient at restUpto 10 ECG sticky pads/self adhesive

electrodes are attached on the skin of the arms leg and chest.

Three lead ECG is most common and the 12 lead ECG gives 12 points of view so heart activity can be accurately analysed.

(chest may need to be shaved)

Normal Sinus Rhythm (NSR)According to Wicker & O neil (2006)-

The sinus node produces an electrical impulse launching a normal heart rhythm

Signal radiates through right and left atrial muscles producing electrical changes

stimulating atria causing atrial contraction (P wave) Impulse continues through AV node conducting electricity at

slower pace (PR interval) Pause between atrial and ventricular systole-blood empties from

atria into ventriclesVentricular contraction (QRS) –blood propels towards aorta and

pulmonary arteryT wave- ventricles relaxing

Atrial contraction/ depolarisation(systole)

Ventricular relaxation/repolarisation

QRS: Ventricular contraction

This cardiac cycle repeats to create a rhythm

Normal Heart rates: ADULT 60-80 BPMCHILD 100BPMINFANT 150BPM*Depends on health, mental state and

BMI

Sinus BradycardiaSlow heart rate with normal sinus rhythmCan be benign but can be caused by beta blockers,

hypothermia, stimulation of the vagus nerve, hypothyroidism etc

Sinus TachycardiaFast heart rate at normal rhythmCaused by shock, drug actions (e.g. Atropine),

anxiety, hypovolaemia etc

Other Abnormal heart rhythms:

Supraventricular tachycardia (SVT) impulse stimulating heart not coming from Sinus

node, instead comes from tissue around AV node. HR up to 280 BPM

Ventricular tachycardia tisues in ventricles casuing rapid irregular Heart

rhythmAtrial FlutterRapid heart rhythm. Abnormal. Impulse bypasses AV

node

Other Abnormal heart rhythms:

Atrioventricular block (AVB)Block in conduction between Sinus node and AV node. 2nd degree heart block- some signals from atria don’t

reach ventricles= dropped beats3rd degree= AV block means no impulses passing

through AV node so ventricles create own rhythmPremature atrial contraction (PAC)Sinoatrial node fires early= early atrial contractionPremature ventricular contraction (PVC)Av node fires early- ventricles contract early

Other Abnormal heart rhythms:

Atrial FibrillationElectrical impulses fired irregularly from

many sites in atriaAsystoleEnd of heartbeats, lack of electrical

activity but not straight line so still some continuing residual activity

Blood pressure monitoring

Blood pressure - what is it?Adequate blood pressure is essential to the

bodyBlood pressure is the force exerted on the

arteries.It results from two forces

Blood pressure types of measurement Blood pressure cuff manual

or aneroid monitor.

Types of monitoring The digital reader

http://www.nhlbi.nih.gov/health/dci/Diseases/Hbp/HBP_WhatIs.html http://www.mayoclinic.com/health/low-blood-pressure/DS00590 http://www.essortment.com/lifestyle/useprofessional_sine.html http://www.davidgregory.org/measuring_bp.htm

Good articlehttp://www.medind.nic.inmaa/to3/il/maato3i1psi/polf

Arterial pressure monitoring

Why is it needed?To show beat to beat variation in the arterial

trace.

Other parameters that can be measured.

Myocardial contractility.Vascular tone.

When would it be needed?Constantly changing clinical parameters in

sick patients.

Blood sampling- helpful multiple samples are needed.

Acute interventions-major surgery.

Where is it used?Arm- radial, brachial and axillary arteries.

Leg- dorsalis pedis, posterior tibialis and femoral.

Transducer should be positioned level with heart to give accurate reading.

How is it measured?Transducer energy one form to another.

Pressure change causes movement within transducer.

This creates electrical current to be displayed on oscilloscope.

Placing the lineDecide the anatomical sitePalpate the artery.Clean area thoroughly-local anaesthetic?Seldinger technique- guidewires can be used

to assist in insertion of the cannula up the lumen of the artery.

Remove the needle, thread a cannula over the wire and up the artery before removing the wire.

Mark the arterial line to indicate it presenceSo as not to be mistaken for a venous lineEnsure there is no air within the line Use heparinised saline to flush

Complications!!

Disconnection causing bleedingIncorrect injection of drugsArterial occlusionHaematomaNerve damageEmbolisAneurysm formation