Managing Acute Shortness of Breath: Prioritizing ABCDE Approach

When dealing with acutely unwell patients experiencing shortness of breath, it is crucial to follow the ABCDE approach. The first step is to address Airway and Breathing by sitting the patient up and administering high flow oxygen to maintain normal saturations. Only then should Circulation be considered, which may involve cannulation and administering IV furosemide.

According to the latest NICE guidelines, non-invasive ventilation should be considered as part of non-pharmacological management if simple measures do not improve symptoms.

It is important to prioritize the ABCDE approach and not jump straight to administering medication or inserting a urinary catheter. Establishing venous access and administering medication should only be done after ensuring the patient’s airway and breathing are stable.

If the patient has an adequate systolic blood pressure, iv nitrates such as glyceryl trinitrate (GTN) infusion could be considered to reduce preload on the heart. However, most patients can be treated with iv diuretics, such as furosemide.

In cases of acute pulmonary edema, close monitoring of urine output is recommended, and the easiest and most accurate method is through catheterization with hourly urine measurements. Oxygen should be given urgently if the patient is short of breath.

In summary, managing acute shortness of breath requires a systematic approach that prioritizes Airway and Breathing before moving on to Circulation and other interventions.

Fallot’s Tetralogy

Fallot’s tetralogy is a congenital heart defect that consists of four features: ventricular septal defect, pulmonary stenosis, right ventricular hypertrophy, and an over-riding aorta. To diagnose this condition, doctors look for specific indicators. A step-down in oxygen saturation between the left atrium and left ventricle indicates a right to left shunt at the level of the ventricles, which is a sign of ventricular septal defect. Pulmonary stenosis is indicated by a significant gradient of 89 mmHg across the pulmonary valve, which is calculated by subtracting the right ventricular systolic pressure from the pulmonary artery systolic pressure. Right ventricular hypertrophy is diagnosed by high right ventricular pressures and a right to left shunt, as indicated by the oxygen saturations. Finally, an over-riding aorta is identified by a further step-down in oxygen saturation between the left ventricle and aorta. While this could also occur in cases of patent ductus arteriosus with right to left shunting, the presence of the other features of Fallot’s tetralogy makes an over-riding aorta the most likely cause of reduced oxygen saturation due to admixture of deoxygenated blood from the right ventricle entering the left heart circulation.

Causes of Pulseless Electrical Activity

Pulseless Electrical Activity (PEA) occurs when there is a lack of pulse despite normal electrical activity on the ECG. This can be caused by poor intrinsic myocardial contractility or a variety of remediable factors. These factors include hypoxemia, hypovolemia, severe acidosis, tension pneumothorax, pericardial tamponade, hyperkalemia, hypocalcemia, poisoning with a calcium channel blocker, or hypothermia. Additionally, PEA may be caused by a massive pulmonary embolism. It is important to identify and address the underlying cause of PEA in order to improve patient outcomes.

Hypokalaemia and Hyperkalaemia

Hypokalaemia is a condition characterized by low levels of potassium in the blood. This can be caused by excess loss of potassium from the gastrointestinal or renal tract, decreased oral intake of potassium, alkalosis, or insulin excess. Additionally, hypokalaemia can be seen if blood is taken from an arm in which IV fluid is being run. The characteristic ECG changes associated with hypokalaemia include S-T segment depression, U-waves, inverted T waves, and prolonged P-R interval.

On the other hand, hyperkalaemia is a condition characterized by high levels of potassium in the blood. This can be caused by kidney failure, medications, or other medical conditions. The changes that may be seen with hyperkalaemia include tall, tented T-waves, wide QRS complexes, and small P waves.

It is important to understand the causes and symptoms of both hypokalaemia and hyperkalaemia in order to properly diagnose and treat these conditions. Regular monitoring of potassium levels and ECG changes can help in the management of these conditions.

Cardiovascular Conditions and Marfan Syndrome

Marfan syndrome is a genetic disorder that affects the connective tissue and can lead to various cardiovascular conditions. One of the most common complications is aortic aneurysm, which occurs when the ascending aorta becomes dilated and can result in acute aortic dissection. Additionally, the stretching of the aortic valve annulus can cause aortic regurgitation. Marfan syndrome is caused by a mutation in the FBN1 gene and can be differentiated from other connective tissue disorders such as Ehlers-Danlos syndrome, pseudoxanthoma elasticum, and homocystinuria.

Aortic valve stenosis, on the other hand, is not associated with Marfan syndrome and is caused by either senile calcific degeneration or a congenital bicuspid aortic valve. Coarctation of the aorta is associated with Turner syndrome and presents with hypertension in the upper extremities and hypotension in the lower extremities. Ventricular septal defects and Ebstein’s anomaly are also not associated with Marfan syndrome.

In summary, Marfan syndrome can lead to various cardiovascular complications, and it is important to differentiate it from other connective tissue disorders and understand the associated conditions.

Electrocardiogram Changes and Symptoms Associated with Electrolyte Imbalances

Electrolyte imbalances can cause various changes in the electrocardiogram (ECG) and present with specific symptoms. Here are some of the common electrolyte imbalances and their associated ECG changes and symptoms:

Hypokalaemia:
– ECG changes: small T-waves, ST depression, prolonged QT interval, prominent U-waves
– Symptoms: generalised weakness, lack of energy, muscle pain, constipation
– Treatment: potassium replacement with iv infusion of potassium chloride (rate of infusion should not exceed 10 mmol of potassium an hour)

Hyponatraemia:
– ECG changes: ST elevation
– Symptoms: headaches, nausea, vomiting, lethargy
– Treatment: depends on the underlying cause

Hypocalcaemia:
– ECG changes: prolongation of the QT interval
– Symptoms: paraesthesia, muscle cramps, tetany
– Treatment: calcium replacement

Hyperkalaemia:
– ECG changes: tall tented T-waves, widened QRS, absent P-waves, sine wave appearance
– Symptoms: weakness, fatigue
– Treatment: depends on the severity of hyperkalaemia

Hypercalcaemia:
– ECG changes: shortening of the QT interval
– Symptoms: moans (nausea, constipation), stones (kidney stones, flank pain), groans (confusion, depression), bones (bone pain)
– Treatment: depends on the underlying cause

It is important to recognise and treat electrolyte imbalances promptly to prevent complications.

Lachmann test

Cardiac Abnormalities and their Clinical Findings

Atrial Septal Defect:
Atrial septal defect is characterized by a prominent right ventricular cardiac impulse, a systolic ejection murmur heard best in the pulmonic area and along the left sternal border, and fixed splitting of the second heart sound. These findings are due to an abnormal left-to-right shunt through the defect, which creates a volume overload on the right side. Small atrial septal defects are usually asymptomatic.

Pulmonary Valve Stenosis:
Pulmonary valve stenosis causes an increased right ventricular pressure which results in right ventricular hypertrophy and pulmonary artery dilation. A crescendo–decrescendo murmur may be heard if there is a severe stenosis. Right atrial enlargement would not be present.

Mitral Regurgitation:
Mitral regurgitation would also present with a systolic murmur; however, left atrial enlargement would be seen before right ventricular enlargement.

Mitral Stenosis:
Mitral stenosis would present with an ‘opening snap’ and a diastolic murmur.

Aortic Stenosis:
Aortic stenosis is also associated with a systolic ejection murmur. However, the murmur is usually loudest at the right sternal border and radiates upwards to the jugular notch. Aortic stenosis is associated with left ventricular hypertrophy.

Clinical Findings of Common Cardiac Abnormalities

Treatment Options for Mitral Valve Disease

Mitral valve disease can be managed through various treatment options depending on the severity and type of the condition. Balloon valvuloplasty is the preferred option for symptomatic patients with mitral stenosis, while mitral valve repair is the preferred surgical management for mitral regurgitation. Aortic valve replacement is an option if the aortic valve is faulty. Mitral valve replacement with a metallic valve requires high levels of anticoagulation, and therefore repair is preferred if possible. The Blalock–Taussig shunt is a surgical method for palliation of cyanotic congenital heart disease. Mitral valve repair may be considered in patients with mitral stenosis if the valve anatomy is unsuitable for balloon valvuloplasty. However, if the patient has severe symptomatic mitral stenosis with signs of heart failure, mitral valve replacement would be the first line of treatment.

Treatment Options for Mitral Valve Disease

Diagnostic Investigations for Cardiac Conditions

When a patient presents with signs and symptoms of a cardiac condition, various diagnostic investigations may be performed to determine the underlying cause. In the case of a patient with chest tightness, the first-line investigation is usually an electrocardiogram (ECG) to rule out acute coronary syndrome. However, if the patient is suspected of having aortic stenosis (AS), the best diagnostic investigation is an echocardiogram and Doppler to measure the size of the aortic valve. A normal aortic valve area is more than 2 cm2, while severe AS is defined as less than 1 cm2.

Other diagnostic investigations for cardiac conditions include a coronary angiogram to assess the patency of the coronary arteries and potentially perform an angioplasty to insert a stent if any narrowing is found. Exercise tolerance tests can also be useful in monitoring patients with a cardiac history and heart failure classification. However, a D-dimer test, which is used to diagnose pulmonary embolism, would not be indicated in a patient with suspected AS unless there were additional features suggestive of a pulmonary embolism, such as calf tenderness.