Which ONE of the following statements about aortic dissection is TRUE?
Answer: D: The biggest risk factor for aortic dissection is hypertension. Other risk factors include Marfan’s syndrome, other connective tissue disorders such as Ehlers-Danlos, aortic valve disease, Turner’s syndrome and coarctation of the aorta. Atherosclerosis has no clear role in aortic dissection and is rarely found at the site where dissection occurs.
Presentation varies depending on the patient, the location and the extent of the dissection. The most common feature is pain, often described more as sharp than tearing or ripping pain. Nausea, vomiting, light headedness, diaphoresis and apprehension are also commonly present. The location of the pain suggests where the lesion could be, for example, anterior chest pain – ascending aorta, neck and jaw – aortic arch, interscapular – descending and lumbar/ abdominal pain – below the diaphragm. Neurological symptoms such as focal neurological deficits, cerebral vascular accident (CVA), altered mental state or coma, occur in <20% cases. Syncope may occur as a result of extension into the pericardium causing tamponade or as a result of interruption of cerebral vascular blood flow.
CXR is a useful test; however, it is not very specific and is abnormal in about 80–90% patients. The abnormalities can be quite subtle. Some of the CXR features suggestive of aortic dissection include widening of the mediastinum, left pleural effusion, apical capping, loss of aorto-pulmonary window and deviation of the trachea and oesophagus to the right. It is an inadequate test to rule out an aortic dissection. Angiography is still thought of as the gold standard as it provides anatomical information regarding the path of the dissection; however, the risks of intravenous contrast and time delay doesn’t make it a favourable investigation.
MRI is the ideal investigation as there is no radiation, it is 100% sensitive and specific and it demonstrates the anatomical features and extent of aortic dissection well. However, availability can be an issue, it is time consuming and is not suitable for unstable patients. CT is the imaging modality of choice for most, despite the exposure risk of radiation and contrast and it not providing the best anatomical information or assessment of the aortic valve and the aortic branching vessels. It has the advantage of accessibility and it is a more rapid test than MRI or angiography. Its sensitivity is up to 90%, specificity 90–100%.
Trans-oesophageal echocardiogram is also an investigation that can be considered. It can be as good as angiography if the operator is experienced. However, though accessibility is on the increase it can still be limited. As this investigation is invasive and sedation is necessary, it can be unsuitable in un-intubated unstable patients. DeBakey I (ascending, aortic arch and descending aorta) and II (ascending aorta) or Stanford type A (DeBakey I and II, proximal aorta and varying length of descending aorta) proximal dissections require surgical intervention.
Patients with distal dissections – DeBakey III (descending aorta only) or Stanford type B (distal aorta) – are considered high surgical risk therefore tend to be managed medically in the first instance. Surgical intervention is considered if these patients have ongoing pain, major vessel involvement, poorly controlled hypertension or aortic rupture but they have a higher mortality rate. Medical therapy is aimed at reducing the shearing forces and reducing the blood pressure to around systolic BP 100–120 mmHg with a HR of 60 bpm.
References:
Which ONE of the following statements about haemorrhoids is most CORRECT?
Answer: B: Bright red rectal bleeding with defaecation is the most common presenting compliant in patients with haemorrhoids. Other presenting features include a swelling that may be painful if thrombosed, pruritis ani or mucoid discharge. Internal haemorrhoids can prolapse and need surgical referral if they do not spontaneously reduce or cannot be manually reduced. Portal hypertension is not a cause of haemorrhoids. Rectal varices can cause rectal bleeding in a patient with portal hypertension.
About one-third of pregnant women develop haemorrhoids, predominantly in the later stages of pregnancy. This is a result of direct pressure on the haemorrhoidal vein reducing venous drainage. Traumatic delivery increases the incidence of thrombosed haemorrhoids.
Internal haemorrhoids lie above the dentate line, have visceral innervation, are submucosal and appear beefy red when they prolapse. External haemorrhoids originate below the dentate line, have somatic innervation, are subcutaneous, and are covered by squamous epithelium so appear skin coloured when they prolapse. External haemorrhoids have a blue/ purple appearance when they are thrombosed.
Thrombosed external haemorrhoids should not be incised because this can lead to incomplete evacuation of the clot, rebleeding, swelling and is associated with formation of perianal skin tags. They should be excised and this can be done in the ED. Most benefit is achieved if this procedure is done within the first 48 hours of symptoms, as this is when the thrombosed haemorrhoid is most tense and most painful. After 48 hours it starts to become softer and the pain is more tolerable.
Regarding pilonidal sinus, which ONE of the following statements is TRUE?
Answer: B: Pilonidal sinus is most frequently seen in patients under the age of 40. Recurrence rates are 20–40%. It is uncommon in those over 40 years even if they experienced an episode when they were younger. Although there is still much controversy over the exact pathophysiology of pilonidal sinus, it is thought by most that it is caused by an infected hair follicle. When it ruptures the infection spreads into the subcutaneous tissue causing a foreign body reaction and abscess formation. The contents of the abscess then track to the skin through a sinus tract. The sinus usually contains hair and debris.
Pilonidal sinus is more common in males than females and more common in patients who are overweight and hirsute. Patients with a family history of the same, those with a sitting occupation or have repetitive trauma to the region may have an increased incidence of the disease.
Definitive management is surgery. It should not be done in the ED. The patient can be treated with antibiotics such as augmentin plus metronidazole if there is evidence of cellulitis or abscess formation.
Regarding infection of the breast, which ONE of the following statements is the most CORRECT?
Answer: D: Oral antibiotics, analgesia and encouraging milk flow either by continued breastfeeding or expression via manual methods or the use of a breast pump is the mainstay of treatment. This strategy reduces the rate of abscess formation.
Staphylococcus aureus is the most common pathogen, including MRSA. Other causative organisms include Streptococci and Staphylococcus epidermidis. In non-lactating women, breast infections can also be caused by the aforementioned organisms, as well as enterococci and anaerobes such as bacteroides.
Therapeutic guidelines suggest:
If the patient has severe infection, cellulitis or signs of sepsis then intravenous antibiotics should be administered.
Co-amoxiclav or a macrolide can also be used to treat lactating infection. Tetracyclines, ciprofloxacin and chloramphenicol should be avoided as they are expressed in the breast milk and are harmful to the baby. Regarding analgesia, there has been a small trial that compared the use of cold or room temperature cabbage leaves with ice packs in relieving the breast pain associated with infection. The results demonstrated they have similar efficacy.
In Australia about 20% of lactating women develop mastitis, the incidence is most common before the baby is three months of age. Approximately 10% of those who have mastitis develop a breast abscess. Breast abscess requires surgical management with either percutaneous aspiration or open drainage.
Risk factors for developing a breast infection in non-lactating women include smoking and diabetes. In this group recurrent episodes are common.
An important diagnosis to consider if the patient’s condition is not improving with adequate treatment or if presentation is atypical, is inflammatory breast cancer.
Which ONE of the wounds described below is MOST suitable for delayed primary closure?
Answer: B: Animal or human bite wound(s) to the hand should not be closed primarily. The wound in question should be cleaned, irrigated and debrided then packed with sterile saline-soaked gauze and dressed. Wound review should occur daily.
By day 4 or 5 the wound may be closed if there is no evidence of infection. When wound closure is performed at this stage in the healing process, the proliferative phase, there is no interruption of the process and therefore no delay in final healing. The results are similar to that of primary healing. The treating clinician should assess each wound for risk of infection. If the wound is contaminated or remains so despite cleaning, irrigating and debridement then wound closure options include delayed primary closure or letting the wound heal by secondary intention. If the wound is deemed to be clean or has low risk of infection then it may be closed primarily.
An example of wounds that should be considered for delayed primary closure include:
Laceration from glass can be treated by primary closure if there is no underlying tendon injury that requires surgical exploration and repair. The laceration from the surfboard is not a contaminated wound and is easily cleaned with irrigation. This wound may be closed primarily. High pressure irrigation is the most effective method of cleaning wounds. In the ED using an 18-gauge needle or cannula attached to a 50 or 60 mL syringe may suffice (this generates approximately 5–8 PSI of pressure, which is the recommended irrigation pressure). Irrigation reduces the risk of infection and assists in the removal of foreign bodies. Tap water or 0.9% normal saline can be used for irrigation. Evidence has demonstrated that there is no significant difference between the two.
Pretibial skin flaps in elderly patients should not be sutured and are better left to heal by secondary intention. The skin is usually thin and friable, there is little subcutaneous fat and it can be tricky to get good wound apposition. If sutured these wounds are prone to necrosis.
Management of pretibial lacerations involves a variety of factors. As well as taking into account the time since the injury and the extent of the injury, it is important also to consider the patient’s mobility, medications, level of independence and comorbidities, as these effect wound healing.
It is advisable not to suture pretibial lacerations. Where possible skin edges should be gently apposed and Steri-strips applied with a non-adherent dressing. It is essential that the wound is not placed under any tension as this increases the chance of necrosis and delayed wound healing. If the wound is larger, the skin flap should be spread, a non-adherent silicon based dressing applied followed by a double layer of tubular bandage. A flap that is deeper (e.g. involving 50% of the dermal layer) can be treated in a similar way using a hydrogel sheet dressing. The hydrogel sheet dressing is also useful if there is some degree of necrosis and haematoma. Wounds that involve the entire dermis require surgical intervention; debridement and skin grafting is likely.
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