Regardless of whether your patient is 45 or 85 years old, when they report chest pain, it usually makes a nurse feel nervous.

Maybe the cause of the chest pain is nothing more than indigestion, a muscle strain, or some other innocuous problem. However, often the pain can point to a more serious and potentially life-threatening cause such as an acute myocardial infarction (AMI). For this reason, chest pain must always be considered cardiac in nature until proven otherwise.

Most facilities have chest pain protocols to prevent a heart attack from slipping by them.

Some standards of care are universal and can help you navigate the waters of what can sometimes be a tricky situation.

Making an Accurate Chest Pain Assessment

Perhaps the most important skill a nurse can bring to any situation is an ability to perform an accurate assessment of their patient. This is particularly the case when a patient is experiencing chest pain, as it will help determine whether the pain is cardiac in nature. Just as important is the ability of the nurse to do this in a calm and controlled manner.

There are many different ways of assessing chest pain. A popular method is the ‘PQRST’ pain assessment:

P – Position/Provoking Factors

• Where is the pain? Can you point to it?
• What makes the pain better?
• What makes the pain worse?
• What were you doing when the pain started?
• Does the pain change with repositioning?

Tip: Repositioning tends not to change chest pain caused by an AMI. If repositioning improves the pain, perhaps the issue is of musculoskeletal origin, pleuritic, or pericarditis (where the pain is sometimes relieved by sitting up and leaning forward). Over 40% of women who experience AMIs do not present with pain; they may experience other symptoms such as shortness of breath (review lung sounds), dizziness, nausea, back pain or just unexplained tiredness and fatigue.

Q – Quality

• Can you describe the pain or discomfort?
• Is it a dull ache, sharp, stabbing or crushing pain?

Tip: 70-80% of pain associated with an AMI is reported in the middle/upper sub-sternal region and the pain is often described as “constricting” or a “crushing” sensation. However, sometimes the pain is atypical or even absent (a silent myocardial infarction (MI)). Patients with diabetes can present with a silent MI. It must be remembered that every patient is different and they will not all present with the classic sub-sternal chest pain.

R – Radiation

• Does the pain radiate to any other areas? Can you point to it?

Tip: Roughly 66% of patients with an AMI will experience radiating pain. Common sites include the anterior chest, shoulders and arms. Less common is pain that extends to the neck and jaw. Some patients may describe their pain radiating to the jaw and feeling like a dull ache or a tooth ache, whilst some may describe the radiation as a band around the ribs.

S – Severity/Symptoms

• Can you rate the pain out of ten?
• Any other symptoms?

Tip: Accompanying symptoms of an AMI may include nausea, vomiting and diaphoresis. The patient may also experience dizziness, hypotension and bradycardia or a feeling of impending doom and feeling scared.

T – Time

• How long have you had the pain for?
• Is the pain intermittent (starts and stops) or is it continuous (ongoing)?

Tip: Angina typically lasts for 2-5 minutes (but can last up to 30 minutes) if the precipitating factor is relieved, for example exercise. Pain associated with AMI is not usually intermittent.

I Think the Chest Pain is Cardiac in Nature… What do I do Now?

There are a few important principles that need to be considered when managing myocardial ischaemia. Firstly, the heart is a muscle that needs its own blood supply. The harder the heart works, the more oxygen it requires. Basically, we want to increase oxygen supply to the heart and reduce oxygen demand.

Goal Directed Oxygen Therapy

Clinical guidelines on the management of acute coronary syndromes (ACS) published by the National Heart Foundation of Australia and the Cardiac Society of Australia and New Zealand state that ‘the routine use of supplemental oxygen is not recommended’ (2011).

Oxygen therapy is only indicated in the hypoxic patient with a SpO2 less than 93%, or in patients where there is evidence of shock. In a patient that is not hypoxic (SpO2 >94%) the benefit of oxygen therapy is uncertain and may even be harmful (see ‘Understanding COPD and the Hypoxic Drive to Breathe‘).

Coronary Vasodilators (Glyceryl Trinitrate)

Gylceryl trinitrate (GTN) is available as a sublingual spray or tablet, transdermal patch, or can be administered via intravenous infusion. Nitrates act on vascular smooth muscle, producing a vasodilator effect on the veins and arteries, which in turn reduces intracellular calcium levels and leads to vasodilation. GTN is often indicated in the setting of chest pain as it dilates the coronary vessels, improving coronary perfusion and oxygen supply to the heart.

It is common for healthcare policies in their management of chest pain protocols to state that GTN can be nurse-initiated in the setting of chest pain. GTN is usually contraindicated in a patient with hypotension, as it can further decrease blood pressure due to its effect on the reduction on preload and stroke volume. Check your health institution policy regarding GTN administration.

Anti-Platelet Aggregators (Aspirin)

Aspirin may be prescribed (if not contraindicated) in the setting of chest pain to reduce the risk of thrombus formation in blood vessels. Aspirin inhibits the formation of thromboxanes, which mediate vasoconstriction and platelet aggregation.

Rest, Reassure and Relieve Pain

Often, in the setting of chest pain, morphine will be prescribed. The primary indicator for morphine is due to its opioid analgesic properties to help relieve the patient’s pain. Additionally though, morphine acts as a vasodilator, improving coronary vessel perfusion, and has anti-anxiolytic properties to help reduce the patient’s anxiety.

What Else Should I do?

• Inform senior staff
• Perform and document vital signs, including the ‘PQRST’ pain assessment
• Perform a 12-lead ECG and have it checked by a medical officer as soon as possible
• Maintain access to a defibrillator
• Order diagnostic blood tests such as a full blood examination (FBE), troponin, biochemistry and electrolytes.

Performing and interpreting a 12-lead ECG is a vital assessment in the setting of chest pain. An ECG will help the medical team determine if and when a patient requires reperfusion therapy to treat the cause of the chest pain.

Some nurses liken reading a 12-lead ECG to trying to decipher hieroglyphics, though many nurses can identify basic ECG changes that may indicate the patient is experiencing ischaemia or has had a myocardial infarction. The best person to read and interpret an ECG is a medical officer or cardiologist. It is useful to compare an ECG to a previous one (taken from the same person) to note any acute changes.

Maintaining access to a defibrillator is included in the current guidelines on the management of acute coronary syndromes (ACS) as a priority in the acute management of chest pain. This is because access to a defibrillator avoids early cardiac death caused by reversible arrhythmias. Patients who are having an AMI can have associated arrhythmias.

Lastly, diagnostic blood tests may be ordered. Commonly, this includes testing a patient’s troponin levels. Troponin is a cardiac enzyme or marker of ischaemia/infarction. Despite newer tests having improved sensitivity, the current guidelines state that an elevated troponin may not always represent ischaemia, thus troponin results must be considered within the context of the entire clinical presentation (including the ECG interpretation).

An accurate assessment of a patient’s chest pain helps identify the likely cause of the pain and leads to prompt and appropriate responses to alleviate the pain and treat the cause. Maintaining a calm and controlled environment is not only essential for the patient’s comfort, but for the nurse’s too!

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References

• Bryant, B & Knights, K 2010, Pharmacology for Health Professionals, 3rd edn, Mosby, Chatswood, NSW, Australia
• Chew, DP, Aroney, CN, Aylward, PE, Azadum, L, Kelly, AM, Ruta, LAM, Tideman, PA, Waddell, J, White, HD & Wilson, AJ 2011, ‘2011 Addendum to the National Heart Foundation of Australia/Cardiac Society of Australia and New Zealand Guidelines for the Management of Acute Coronary Syndromes (ACS) 2006’, Heart, Lung Circulation,  vol. 20, pp. 487-502, viewed 16 September 2016, http://www.csanz.edu.au/documents/guidelines…rithm.pdf
• Chiariello, M & Indolfi, C 1996, ‘Silent Myocardial Ischaemia in Patients with Diabetes Mellitus’, Circulation, viewed 16 September 2016, http://circ.ahajournals.org/content/93/12/2089.full
• National Heart Foundation of Australia n.d., ‘Getting the Facts on Women and Heart Attack’, viewed 16 September 2016, http://heartfoundation.org.au/your-heart/heart-attack-warning-signs

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