Clinical Relevance Flashcards
Rib fractures
Rib fractures result from blunt trauma to the chest wall (falls, traffic accidents, assault). They are painful and the pain is typically worse on inspiration. If there is concern about multiple rib fractures or a pneumothorax, a chest X-ray or CT scan may be required to assess the extent of the injury. Isolated rib fractures are treated conservatively (i.e. left to heal on their own) but patients need adequate pain relief. Multiple rib fractures are more serious (and complex to manage), as they can lead to dysfunctional movements of the chest wall and inadequate ventilation.
Shingles
Patients with shingles present with a red, painful, and itchy rash, typically over the chest or abdomen on one side of the body only. The rash typically appears in a strip-like distribution, as it affects dermatomes. Shingles affects people who have previously had chickenpox. After an infection with chickenpox, the virus lays dormant in the dorsal root ganglion. When reactivated, it causes a rash and pain in the dermatome associated with the affected spinal nerve.
Breast cancer
Because most lymph from the breast drains to the axillary lymph nodes, breast malignancy typically metastasizes (spreads) to these nodes first. A malignant axillary node may be palpable as a lump in the armpit and noticed before a mass in the breast itself. If a breast mass is confirmed as malignant, the axillary lymph nodes are biopsied to assess if malignancy has metastasized to them. If so, they are removed as part of a patient’s treatment. Because the axillary nodes drain lymph from the upper limb, their removal can lead to fluid accumulation and swelling in the affected upper limb, a condition called lymphoedema.
Pleuritic chest pain
The pleura can become inflamed or injured (e.g. torn by a fractured rib). Pleuritic chest pain is typically sharp, well localised (i.e. the patient can pinpoint it on the chest wall), and worse on inspiration. The pain is felt from the parietal pleura only.
Pneumothorax and haemothorax
A pneumothorax is the presence of air in the pleural cavity. It is usually caused by trauma (e.g. a fractured rib tearing the parietal pleura) but can happen spontaneously (tear in the visceral pleura). If air keeps entering the pleural cavity but cannot escape, a tension pneumothorax develops, in which a rapidly increasing volume of air progressively compresses the lung, heart, great vessels and the opposite lung over to the contralateral side of the thorax. This is rapidly fatal without immediate intervention. Patients with a tension pneumothorax present with severe respiratory distress.
Haemothorax describes a collection of blood in the pleural cavity and occurs secondary to trauma when blood vessels are torn or cut.
Pleural effusion
Pleural effusion describes the presence of excess fluid in the pleural cavity. It is not a diagnosis - the fluid could be pus from infection, blood, or fluid related to malignancy. A chest drain is used to remove air and / or fluid from the pleural space. The surface anatomy of the heart and lungs must be considered to ensure the tip of the drainage tube does not injure them. An incision is made in the lower part of the chosen intercostal space, to avoid the neurovascular bundle, which lies in the costal groove of the rib superior to the space.
Lung cancer and mesothelioma
Lung cancer is one of the most common types of cancer seen in the UK. Lung cancer may be primary (i.e. cancer of the lung tissue or bronchi) or secondary (i.e. cancer from elsewhere that has metastasized to the lungs). Both primary and secondary cancer of the lung is common.
Mesothelioma is a malignancy of the pleura.
Pulmonary embolism
Pulmonary embolism is a blood clot in the pulmonary circulation. The clot usually forms in the deep veins in one of the legs and is carried in the venous circulation back to the right side of the heart and into the pulmonary trunk. A very large clot lodging in the pulmonary trunk or in one of the pulmonary arteries causes severe respiratory distress and may be rapidly fatal. Smaller clots that occlude smaller pulmonary vessels may cause infarction of the part of the lung they supply.
Dyspnoea
Patients commonly present with breathlessness or shortness of breath (dyspnoea). The use of the accessory muscles of respiration is a sign of respiratory distress. Patients in respiratory distress will often ‘fix’ their upper limbs steady (e.g. by holding onto the side of the bed or chair), which allows the upper limb muscles that attach to the chest wall (pectoralis major, pectoralis minor and serratus anterior) to move the ribs and aid ventilation.
Paralysis of diaphragm
Injury to the phrenic nerve, the C3-5 spinal nerves or the C3-5 spinal cord segments on one side may paralyse the ipsilateral side of the diaphragm, but in a healthy person, this may not cause symptoms. Patients with bilateral paralysis of the diaphragm require ventilatory support.
Patent ductus arteriosus (PDA)
PDA is a type of congenital cardiac anomaly. The ductus arteriosus usually closes immediately after birth. In some infants, the ductus arteriosus does not close and remains open (patent). After birth, the pressure in the aorta exceeds the pressure in the pulmonary trunk, hence blood flows through a patent ductus arteriosus from the aorta into the pulmonary trunk. Over time, increased flow through the pulmonary vessels can lead to pulmonary hypertension (high pressure in the vessels of the lungs) which strains the right side of the heart.
Hoarseness of the voice and lung cancer
Cancer at the apex of the lung may involve the recurrent laryngeal nerve, which supplies most of the muscles of the larynx. Nerve injury results in weakness or paralysis of the ipsilateral intrinsic laryngeal muscles, which move the larynx and the vocal cords. Hoarseness results as the patient can no longer fully adduct their vocal cords.
Pathology of the pericardium
The pericardial space allows the heart to move within the pericardial sac with each contraction. Pericardial effusion is an increase in fluid volume in the pericardial space. Pericardial effusion may result from inflammation of the pericardium (a condition called pericarditis) or an accumulation of blood (due to trauma). Rapid fluid accumulation in the pericardial space (e.g. blood due to a stab wound) can be rapidly fatal because the fibrous pericardium cannot stretch and so the heart is compressed and unable to fill properly - a condition called cardiac tamponade.
Myocardial infarction
This is the death of a region of myocardium secondary to occlusion (blockage) of the coronary vessel that supplies it. Most commonly, it is caused by atherosclerosis within the coronary arteries. A fatty plaque in a coronary artery may grow until it narrows the vessel lumen (stenosis) and severely restricts blood flowing through it. A fatty plaque may shear from the vessel wall, causing a clot to form in the lumen, which occludes blood flow.
Congenital cardiac anomalies
Patient foramen ovale (PFO) arises when the foramen ovale fails to close after birth. The foramen ovale ‘functionally’ closes shortly after birth and anatomically closes by the time and infant is about one year old. A PFO allows blood to move from the left to the right atrium. Openings can also occur in the interventricular septum. Ventricular septal defects (VSDs) allow blood to flow from the left to the right ventricle. The severity of these defects largely depends on the size of the opening between the chambers.
Valve dysfunction
The AV and semilunar valves may become narrowed (stenosis) or incompetent. Incompetent valves allow regurgitation of blood back into the preceding chamber. Both result in turbulent blood flow that produce murmurs on auscultation. Some valve problems are clinically insignificant, whilst others are severe. Valve dysfunction may be congenital (i.e. the patient is born with it) or acquired. For example, an AV valve may become dysfunctional if a myocardial infarct involves the associated papillary muscles.
Cardiomyopathies
Cardiomyopathies are diseases of myocardium, and most are inherited. There are different types – some cause the myocardium to thin, whereas others result in the myocardium becoming thick and stiff. This affects the heart’s ability to pump efficiently and can lead to heart failure. Unfortunately, some cardiomyopathies have no obvious symptoms and are a cause of sudden cardiac death in otherwise healthy, young people.
Conducting system abnormalities
There are many different types of conducting system abnormalities with varied causes. Myocardial infarction can cause conduction disturbances if the vessels that supply the conducting system are affected. Sometimes patients may have no symptoms and the abnormality is picked up on ECG. Some conducting system abnormalities are life-threatening, but can be managed if they are detected, for example, by fitting a pacemaker or an internal cardiac defibrillator (ICD).
Heart failure
Heart failure occurs when the heart does not pump efficiently. There are many possible causes, including dysfunction of one or more of the heart valves, or an ability of the myocardium to contract properly (e.g. due to damage by myocardial infarction or cardiomyopathy). Signs and symptoms of heart failure include tiredness, shortness of breath and leg swelling.
Cardiac arrest
Cardiac arrest is the cessation of cardiac contraction. Sometimes there is still detectable electrical activity, but the heart does not contract in response. Myocardial infarction and conducting system abnormalities are two causes of cardiac arrest, but there are many more.
Aortic dissection
Dissection in this context refers to a longitudinal tear in the aortic wall that allows blood to collect between the intima and media. It can happen in the ascending aorta, arch, or descending aorta. It typically presents with sudden onset severe chest and / or back pain. Instead of flowing through the ‘true’ lumen of the aorta, blood collects in the ‘false’ lumen created by the tear.
