Questions of the Week for 6/6/2023

Author: Christian Gerhart

A 29 yo female who is 3 months postpartum presents with right breast redness and pain. Her vitals are T 100.7, HR 94, BP 130/80, RR 18, O2 Sat 100% RA. On exam the breast is erythematous and there is warmth and tenderness without an obvious drainable fluid collection. She is overall well appearing. What treatment should be initiated and how should the patient be counseled regarding breast feeding? 

  • This patient likely has mastitis. A breast abscess is in the differential but less likely. She can likely be treated with PO antibiotics. Dicloxacillin is generally first line to cover MSSA, which is the most common pathogen. If refractory, coverage can be broadened to include MRSA coverage. Bactrim needs to be used with caution in breastfeeding mothers and should be avoided if the infant is ill, premature, or has G6PD deficiency. Doxycycline is generally safe in short courses (<21 days). A breast ultrasound can be considered if there is high concern for an abscess. The patient should be advised to continue breastfeeding through the illness.

A 32 yo female presents with chest pain and undergoes a CT PE study which is read as negative. She asks if she should stop breastfeeding after receiving the contrast agent. What should you tell her? 

  • The American College of Radiology supports continuing breastfeeding without interruption in patients who have received iodinated contrast. There is very minimal absorption of contrast into breast milk. You can tell the patient that she can continue breast feeding without interruption. Their recommendations are similar regarding Gadolinium MRI contrast.

You have a patient who presents with myalgias who is found to have a CK of 25,000. What electrolyte abnormalities would you expect to see? 

  • Hyperkalemia, hyperphosphatemia and hypocalcemia. This is similar to tumor lysis syndrome. Potassium and phosphate are intracellular ions that are released as muscle cells die. Hypocalcemia occurs as calcium binds to phosphate. Other lab abnormalities include AST>ALT elevation from muscle breakdown. You may see a UA with +blood but no RBC as the urine dip detects myoglobin.

Your patient with rhabdomyolysis progresses to acute renal failure with a creatinine of 6.5 a bicarbonate of 9, potassium of 6.7 and a pH of 7.15. What treatment can be considered that may have a benefit in preventing the need for renal replacement therapy? 

  • Isotonic bicarbonate can be considered in patients with uremic acidosis. The BICAR-ICU trial demonstrated a reduced need for renal replacement therapy in patients with uremic acidosis with a pH<7.2 and bicarbonate <20. Among patients with severe AKI, there also was evidence of decreased mortality. Isotonic bicarbonate is 150 meq (aka 3 amps) of bicarbonate in 1L of D5W. In general, this can be started at 150mL/hr (with consideration of the patient’s fluid status).

A patient with a history of gout presents with a red, swollen tender knee with a temperature of 99.5F and mildly elevated inflammatory markers. An arthrocentesis is performed which demonstrates a synovial WBC of 51,000. How would you manage this patient? 

  • This is a challenging case which is probably best managed in conjunction with orthopedics. Although gout can cause elevations in the synovial WBC >50,000, this also raises concern for septic arthritis. The gram stain may be helpful, but the synovial fluid should certainly be sent for culture as well. This patient would likely benefit from admission for administration of IV antibiotics to cover for possible septic arthritis until cultures result given how challenging it is to rule out septic arthritis based on this clinical presentation.

How does the diagnosis of native vs. prosthetic joint infection differ?  

  • Usually native joint septic arthritis will have a higher synovial WBC count. In native joints, most patients will have a synovial WBC of >20-50,000. It is always advisable to send a culture as there can be cases with lower WBC numbers but are still septic joints. However, in prosthetic joints, it is more common to have a lower synovial WBC, often in the range of 10,000. Orthopedics should be consulted early if there is concern for prosthetic joint infection. Some orthopedic surgeons may prefer to be involved before an arthrocentesis is performed on a prosthetic joint as they are thought to be at higher risk for seeding with arthrocentesis. For chronically infected prosthetic joints the synovial WBC can be as low as 3,000 in an infected prosthesis.

You have a 29 yo female with no past medical history who presents with a chief complaint of ankle pain. Vitals are T: 99.5, HR 102, BP 120/80, RR 21, O2 sat 99% RA. Her right ankle is mildly swollen and remarkably tender to touch or range of motion. She initially had some left elbow pain which is now resolved but now has right knee pain. What diagnosis is most likely and how should it be managed? 

  • This is an example of a typical presentation of gonococcal arthritis. It is most common in younger patients who are sexually active. Oftentimes patients may not complain of STI symptoms. This should be on our differential for any patient with migratory polyarthralgia. Arthrocentesis should be obtained from whichever joint is most accessible. These patients should have cultures obtained from mucosal sites (urethral, rectal, oropharyngeal) as oftentimes an organism can be identified even if they don’t have symptoms which can assist in the diagnosis. For patients with confirmed disseminated gonococcal infection, the treatment is generally IV ceftriaxone. If there is evidence of septic arthritis on arthrocentesis, orthopedics should be consulted for surgical drainage.

A 3 yo male with no past medical history presents bilateral eye redness. On exam he has bilateral conjunctivitis. You astutely look in his ears and notice he has a right sided otitis media. What syndrome is this most likely to represent and how should it be treated? 

  • This is consistent with otitis-conjunctivitis syndrome which is usually caused by non-typable Hemophilus influenza. These patients should be treated with systemic oral antibiotics. Augmentin is generally the best agent as beta-lactamase producing organisms should be covered. Amoxicillin is generally inadequate. It is important to note that patients may present without ear pain. Remember to examine the ears in patients who present with conjunctivitis.