Respiratory
A 59-year-old male living in Geelong presents to ED with shortness of breath, cough and fever. His observations include respiratory rate of 26 breaths per minute and oxygen saturation of 91% on room air. He is still able to eat and drink normally. What is your diagnosis and what treatment would you recommend?
Moderate CAP – amoxycillin 1g oral TDS plus doxycycline 100mg oral BD for 5 days.
A 63-year-old female presents to the GP with a painful left foot after being bitten by an ant a few days earlier. On examination it is red, swollen and warm. Her observations are all within normal range. What is your diagnosis and antibiotic recommendation?
Cellulitis – flucloxacillin 500mg orally 6 hourly for 5 days.
A 93-year-old female admitted at McKellar Centre awaiting a nursing home placement develops new urinary frequency and confusion. The RMO requests a mid-stream urine and would like to commence empirical antibiotics immediately. She asks you as the medical student what you would recommend. She also asks if your recommendation would change if the patient were male.
1st line is nitrofurantoin 100mg orally 6 hourly for 5 days.
Note lecture notes also mention trimethoprim which is 300mg orally daily (preferably at night) for 3 days and cefalexin which is 500mg orally 12 hourly for 5 days.
Male patient = 7 days treatment.
A 43-year-old male presents to ED with fever and night sweats, weight loss and haemoptysis after recently moving from Tanzania. An acid-fast smear confirms TB. What treatment regime would you recommend?
Isoniazid 10mg/kg up to 300mg orally daily for 6/12 (+pyridoxine 25mg orally daily) +
Rifampicin 10mg/kg up to 600mg orally daily for 6/12 +
Ethambutol 15mg/kg up to 120mmg orally daily for 2/12 +
Pyrazinamide 25mg/kg up to 2g orally daily for 2/12
A 46-year-old male living in Geelong presents to ED with shortness of breath, cough and fever. His observations include respiratory rate of 32 breaths per minute, oxygen saturation of 88% on room air and blood pressure of 80/50mmHg. What is your diagnosis and what treatment would you initially recommend?
Severe CAP - Ceftriaxone 2g IV daily plus azithromycin 500mg IV daily.
A 49-year-old male presents to the ED with a painful left food after being bitten by an ant a few days earlier. On examination it is red, swollen and warm. His temperature is 39 degrees, BP = 90/60mmHg and heart rate is 120 bpm. You look at his previous cultures and note that he had a wound infection last year that grew MRSA. You provide a diagnosis of cellulitis for the foot. What antibiotic would you recommend? Would you be able to provide a dose with the information provided?
Vancomycin. No – dose is based on weight and renal function so not enough information has been provided.
A 36 year old male requires a right hemicolectomy for a tumour of the caecum. The surgeon states afterwards that faecal contamination of the peritoneum has occurred and the patient has developed peritonitis. What antibiotic regime would you recommend and why?
Gentamycin (aminoglycoside – gram negative – inhibits protein synthesis)
Ampicillin (penicillin – gram positive – inhibits cell wall synthesis)
Metronidazole (nitroimidazole – anaerobic - DNA strand breakage and fatal destabilization of the DNA helix)
Intra-abdominal infections are generally polymicrobial and caused by intestinal flora. Empirical therapy for intra-abdominal infections should include antibiotics with activity against:
An aminoglycoside (in combination with amoxicillin or ampicillin) is usually preferred to broad-spectrum penicillins or cephalosporins for empirical therapy because it is active against a greater percentage of Enterobacterales. Aminoglycosides are also less likely to contribute to the development of Clostridioides difficile (formerly known as Clostridium difficile) infection and the selection of antibiotic-resistant organisms.
A 21-year-old female has just started university and is studying nursing. For her first placement a range of tests are required including a quantiferon gold test. This leads to the diagnosis of latent TB. She has a past medical history of endometriosis and is on the oral contraceptive pill. She has no risk factors for multi drug resistant TB. What antibiotic regime would you recommend and why?
Isoniazid 10 mg/kg up to 300 mg orally, daily for 9 months
(Other option is rifampicin 10 mg/kg up to 600 mg orally, daily for 4 months, however it interacts with the pill by inducing liver enzymes particularly CYP3A4 which increases the metabolism of the pill)
A 12-year-old boy from Mutitjulu presents to his clinic with a sore throat and enlarged tonsils with exudate. A swab is taken and grows Streptococcus pyogenes (Group A Strep). What is your recommendation and why?
Treat with phenoxymethylpenicillin 15mg/kg up to 500mg orally 12 hourly for 10 days as he is an Aboriginal person living in a remote community and therefore at increased risk of acute rheumatic fever.
A 63-year-old female is chopping vegetables when she accidentally drops the knife on her big toe. Although it was very painful and she thinks the knife hit her bone, she does not think it requires stitches so does not seek medical attention. A few weeks later the toe becomes red, painful, hot and swollen. She attends her local emergency department where she is diagnosed with osteomyelitis. A blood culture comes back negative and bone biopsy grows pseudomonas aeruginosa. What oral antibiotic do you recommend (and why)?
Ciprofloxacin 750mg 12 hourly.
A 60-year-old male is diagnosed with Mantle cell lymphoma and planned to commence R-CHOP. You are working in the haematology unit. What prophylactic antibiotic (including dose) would you recommend and why?
Trimethoprim/sulfamethoxazole 160mg/800mg on Mondays/Wednesdays/Fridays to prevent Pneumocystis jirovecii pneumonia.
You have just moved to Darwin and have your first shift in the emergency department at Royal Darwin Hospital. A 56-year-old female presents with cough, fever and shortness of breath. Her GP had diagnosed her with pneumonia and she has just completed a course of amoxicillin 1g TDS, however her symptoms have not improved. When taking her history, you learn that she identifies as Aboriginal and has a past medical history of type 2 diabetes, chronic kidney disease and alcohol misuse. What do you suspect is her diagnosis and what treatment would you recommend?
Melioidosis – Ceftazidime 2g IV 6hrly for at least 14 days (for non-neurological symptoms, without septic shock and not requiring ICU), followed by eradication therapy with trimethoprim/sulfamethoxazole 320mg/1600mg po BD for 3 – 6 months plus folic acid 5mg daily.
A 9-year-old boy presents from Ampilatwatja to his local clinic with a rash that is thick and has scaly plaques and is located in between his fingers. There is minimal itching. His blood results show eosinophilia. What is your diagnosis and treatment recommendation?
Crusted scabies – ivermectin 0.2mg/kg either a 3-dose regime (days 1, 2 + 8), 5 dose regime (days 1, 2, 8, 9 + 15) or 7 dose regime (days 1, 2, 8, 9, 15, 22 + 29) depending on severity.