A 27-year-old male presents with a 1-day history of jaundice, fever, nausea and RUQ pain 4 weeks after returning from India. Viral studies show antihepatitis A virus (anti-HAV) IgM positive. He has a wife and a 6-year-old child at home. They are not vaccinated.
Which ONE of the following is TRUE?
Answer: B: This man has contracted hepatitis A. Transmission is usually by the faecal–oral route and incubation period is 2–6 weeks. He will be infectious approximately 2 weeks before the onset of jaundice until 1 week after the onset of jaundice.
NHIG should be given as a single intramuscular injection to close contacts of hepatitis A cases to prevent secondary cases. NHIG should be administered to close contacts within 2 weeks of the last exposure to the case. NHIG may not be effective if given >2 weeks after the exposure. ‘Close contacts’ are those who have had contact with a case during the 2 weeks before, up until 1 week after the onset of jaundice, and usually include only household and/or sexual contacts (but in some circumstances may include close occupational exposure).
Although one study suggests that hepatitis A vaccine may be effective in preventing secondary cases of hepatitis A in close contacts, there is currently insufficient evidence to be able to recommend it for this purpose.
Reference:
Regarding liver function tests, which ONE of the following is TRUE?
Answer: C: An increase in conjugated bilirubin indicates obstruction, preventing the secretion of conjugated bilirubin produced by normally functioning hepatocytes. It is due to either:
The transaminases (AST and ALT) are commonly used to detect acute hepatocyte injury. They are intracellular hepatic enzymes and are released into the circulation with hepatocyte injury. AST, however, is not specific to hepatocytes and also occurs in other cells, for example, the heart, smooth muscle, kidney and brain. Therefore, ALT is a more specific marker of hepatocyte injury than AST.
ALP elevation is associated with biliary obstruction and cholestasis. Mild to moderate elevations accompany virtually all hepatobiliary disease, whereas elevations >4 times normally strongly suggests cholestasis. Again, ALP is a non-specific marker as it is also derived from bone, placenta, intestines kidneys and leucocytes. Therefore, in the absence of elevated gamma-glutamyl transpeptidase (GGT), causes other than cholestasis should be considered. GGT is slightly more sensitive than ALP in obstructive liver disease. It is also elevated by drugs inducing hepatic microsomal enzyme activity, such as warfarin, phenytoin and baribiturates. There may be an isolated elevation in chronic ethanol ingestion or chronic barbiturate or phenytoin therapy.
Urine bilirubin and urobilinogen are sometimes used as screening tests for liver disease in the ED. The sensitivities of these urine assays are 70–74% for identifying elevated serum bilirubin. For correlation with other liver enzyme tests, their sensitivity is in the 43–53% range. Specificity for showing either bilirubin or transaminase abnormality is 77–87%. Blood-tinged urine will give a false positive urobilinogen on urine dipstix. Taken together, these statistics do not support screening for liver disease with urine dipstick testing.
References:
You are requested to insert a nasogastric tube (NGT) into a 48-year-old male with a small bowel obstruction.
Which ONE of the following statements is TRUE?
Answer: D: The tube insertion length should be estimated prior to insertion of a NGT to prevent placement of the tip of the tube in the oesophagus and to ensure intragastric positioning without excess coiling. The distance should be measured from the tip of the xiphoid to the earlobe. Add the distance from the earlobe to the tip of the nose. Then add another 15 cm. Typically, a 16- or 18-Fr sump tube is used in adults for aspiration/drainage. Sizes are available up to size 20.
Vasoconstrictors and topical anaesthetics should always be used whenever the time and clinical situation permit. The nares, nasopharynx and oropharynx should all be anaesthetised at least 5 minutes before the procedure. Gagging is reduced if the pharynx is anaesthetised as well as the nose. Lignocaine 1% or 4% nebulised through a face mask (≤4 mg/kg; not to exceed 200 mg per dose in adults) is an option and seems to be superior to lignocaine spray to reduce gagging and vomiting and to increase the chance of successful passage. Alternatively, lubrication and anaesthesia of the nares can be facilitated by using a syringe filled with 5 mL of anaesthetic lubricant, such as 2% lignocaine gel. Simply putting anesthetic jelly on the tube before insertion will not provide any anesthesia.
Successful tube placement can most accurately be confirmed with X-ray; however, it is not the standard to routinely obtain X-ray confirmation. Aspiration of stomach contents, especially if pH tested, is more reliable than insufflation of air to confirm placement in the stomach. If the pH is <4, there is an approximately 95% chance that the tube is in the stomach and nonrespiratory placement is almost guaranteed.
Regarding a patient presenting to the ED with a fever who has a history of a liver transplant and who is on immunosuppressant therapy, which ONE of the following is TRUE?
Answer: A: Fever is the most common reason for a transplant recipient to present to the ED. Factors other than infection such as rejection, drug effects, hypersensitivity reaction or malignancy can also cause fever and are sometimes indistinguishable from infection. Furthermore, it is often difficult to differentiate infection from rejection and they may also occur simultaneously. For this reason, treatment for rejection and infection are often started at the same time. Consultation with the transplant team should occur early to direct the most appropriate treatment regime. The timing of infection after transplant can be separated into three periods, which is helpful in determining the aetiological agent:
1. <1 month Fever is usually due to complications of surgery and hospitalisation. Nosocomial pathogens are prominent.
2. 1–6 months
a) immunomodulating viral infections including cytomegalovirus (CMV), hepatitis B and C, and Epstein-Barr virus (EBV)
b) opportunistic infections including Pneumocystis, Listeria, and fungal species
3. >6 months Infections are further divided into three groups relative to infection susceptibility:
a) healthy transplant – community-acquired infections
b) chronic viral infection – progressive disease due to immunomodulating viral infections
c) chronic rejection – opportunistic infection predominate
NSAIDs should generally be avoided as many transplant patients will have recurrent bouts of thrombocytopenia from chemotherapy or renal insufficiency as a side effect of immunosuppresive drugs. Some patients will be on anticoagulants due to deep venous thrombosis (DVT) or other reasons, whereas others will have unexpected episodes of bleeding due to transplant complication or graftversus-host disease.
A 29-year-old female with a liver transplant requires transfusion of blood products in the ED.
Answer: A: Transfusion-associated graft-versus-host disease (TA-GvHD) is a rare, but almost universally fatal, iatrogenic complication of transfusion. It occurs when immunocompetent T-lymphocytes engraft in an immune-suppressed patient. Irradiation of cellular blood components (whole blood, red cells, platelets and granulocytes) is the mainstay of TA-GvHD prevention. Frozen blood components, such as fresh frozen plasma and cryoprecipitate, and fractionated products, such as albumin, factor concentrates and intravenous immunoglobulin, do not require irradiation before administration. Unlike most transfusion-related reactions, TA-GvHD usually presents after only a few days, with a median onset of 10 days.
In comparison with patients who have received haematopoietic stem cell transplants, solid-organ transplant recipients are generally less immunocompromised and are subsequently more capable of abrogating the effect of donor lymphocytes and preventing engraftment. For this reason, the Australian and New Zealand Society of Blood Transfusion does not recommend the routine irradiation of cellular blood components for solid organ transplant recipients.
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