LECTURE 4 (Pulse measurement) Flashcards
What is the Pulse?
A pressure wave that is transmitted through the arterial tree with each heart beat following the alternating expansion and recoil of arteries during each cardiac cycle
Where is the Pulse strongest?
In arteries closer to the heart
Explanation: It becomes weaker in the arterioles and disappears in the capillaries altogether
Where are the clinically important arterial pulse points?
- Carotid
- Brachial
- Radial
- Ulnar
- Femoral
- Popliteal
- Posterior tibial
- Dorsalis pedis
The pulse is palpated to note what?
- Rate
- Rhythm
- Amplitude
The arterial pulse is measured to assess what?
- Effects of activity
- Postural changes
- Emotions on heart rate
- Effects of disease
- Treatments & Response to therapy
Explain the physiology of heart beats
Each time the heart beats, it pushes blood through the arteries -> Pumping action causes walls of arteries to EXPAND and DISTEND -> Causes a wave-like sensation which can be felt as the pulse
What are some factors that could act on heart rate?
- Age
- Sex
- Exercise
- Body temperature
- Hormones
- Electrolytes
- Activation of sympathetic and parasympathetic nervous system
What is Tachycardia?
Abnormally fast heart rate over 100 bpm in adults
What is Bradycardia?
Heart rate slower than 60 bpm
When is Bradycardia considered normal?
In fit athletes
When is Bradycardia considered abnormal?
- Normal individuals -> result in inadequate blood circulation to body tissues
- Warning of brain oedema after head trauma -> indication of raised intracranial pressure
What is the Sinoatrial node?
The pacemaker initiating each wave of contraction and sets the rhythm of the heart as a whole. Characteristic rhythm is called SINUS RHYTHM
What do defects in the conduction system of the heart cause?
Irregular rhythms/Arrythmias
[results in uncoordinated contraction of the heart]
What is Fibrillation?
Rapid and irregular contractions of heart muscle
[A fibrillating heart is ineffective as a pump]
What is Atrial Fibrillation?
A disruption of rhythm in the atrial areas of the heart occurring at extremely rapid and uncoordinated levels -> Rapid impulses result in the ventricles not being able to respond to every atrial beat -> Ventricles contract irregularly
What is Ventricular Fibrillation?
Irregular heart rhythm characterised by chaotic contraction of the ventricles at very rapid rates
What are the most common causes of Fibrillation?
- Ischaemic heart disease
- Acute illness
- Electrolyte disbalance
- Thyrotoxicosis
What is distinguishable about Atrial Fibrillation?
Impulses are not generated by the SA node by from different locations of the atria -> Chaotic atrial fibrillating impulses
What is Amplitude?
Reflection of pulse strength and the elasticity of the arterial wall
[varies because of the alternating strong and weak ventricular contractions]
What is a Paradoxical pulse?
A pulse that markedly decreases in amplitude during inspiration
[usually normal but with HYPOTENSION and DYSPNEA -> indicates life-threatening conditions]
What do you do is there is a gross pulse irregularity?
One nurse should use diaphragm of stethoscope to assess APICAL HEARTBEAT and a second should count the RADIAL PULSE at the same time -> Compare results
What are the indications for Pulse measurement?
- Post-op & Critically ill (cardiovascular stability)
- Blood transfusions
(incompatible blood transfusion may lead to a rise in pulse rate early into transfusion) - Patients with local or systemic infections/inflammatory reactions
- Patients with cardiovascular conditions
What do you do if no pulse is palpable?
Incorrect positioning of fingers -> Find palpation sites
What do you do if absent or faint pulse?
- Poor perfusion -> Assess patient’s existing co-morbidities -> identify causes of hypovalemia
- Perform neuromuscular assessment on pulse sites -> feel for warmth, sensation & capillary refill
- Perform VTE assessment
What do you do if the pulse is too fast and irregular to palpate manually?
- Patient may have an abnormal rhythm -> use electronic recording device
- Haemodynamic assessment
- Monitoring and maintenance of electrolyte imbalance
