Identifying hidden sources of sepsis - a challenging diagnosis of septic arthritis in a multidisciplinary renal patient
Case Summary:
A 65-year-old man was admitted to a major rural hospital for an elective left arm fistuloplasty and revision, which failed, resulting in a need to establish an urgent permanent dialysis access. He had a 6 month history of idiopathic left leg swelling, and pain associated with a recent fall onto his left leg 2 weeks prior to the admission. He had significant comorbidities including Type 1 diabetes mellitus, an ST-elevation myocardial infarction in 2014, retinopathy, peripheral neuropathy and end-stage renal failure. He had a failed renal transplant in 2000 and failed peritoneal dialysis. He had peripheral arterial insufficiency and had previously undergone right below-knee amputation.
The patient’s creatinine level was 493 µmol/L. He was on 12.5 mg of prednisone daily. He was admitted under a vascular surgeon with close consultation by a renal physician. On day 2 of admission, he became unwell from Staphylococcus aureus septicaemia secondary to left leg cellulitis. He developed fever, nausea, vomiting, diarrhoea and increasing pain in the left lower leg, which was clinically erythematous and tender. The surgical team was consulted for any potential abdominal cause of sepsis. A CT (computed tomography) scan of the abdomen/pelvis (without contrast) showed a distended gallbladder and gas-fissuring within the gallstones. There was no evidence of intra-abdominal sepsis. A subsequent abdominal ultrasound confirmed no evidence of cholecystitis. The empirical IV (intravenous) antibiotics ceftriaxone, flucloxacillin and metronidazole were requested but there was a 6 hour delay before administration due to difficulty in establishing IV access. Despite this delay, there was initial clinical improvement on the left leg cellulitis over the next 3 days. The patient had continuing intermittent spikes of white cell counts and CRP (C-reactive protein) levels despite the apparent clinical improvement and the continuous antibiotic therapy.
On day 5, a permacath dialysis catheter was inserted via the right internal jugular vein. On day 6, the patient developed poor appetite, delirium and hypotension, which prohibited a successful dialysis session. This condition continued over the next 2 days. On day 9, he redeveloped mild left leg cellulitis in addition to onset of diabetic ketoacidosis and uraemia caused by withholding insulin (for poor oral intake) and lack of sufficient renal dialysis. He was transferred to ICU (intensive care unit) to establish successful renal therapy and to treat ketoacidosis and hypotension. The ICU team noted persistent left leg cellulitis despite the IV antibiotics, and an MRI (magnetic resonance imaging) of the left foot was ordered. The antibiotics were escalated to Tazocin. The MRI showed abnormal soft tissue signals along the entire greater toe, suggesting left big toe chronic osteomyelitis or metatarsophalangeal joint (MTPJ) septic arthritis.
On day 17, a second vascular surgeon was consulted, who identified an ulcer at the medial aspect of the first MTP joint. On day 18, the patient underwent left ray amputation of the greater toe under a left ankle regional anaesthesia. The histopathology confirmed active on chronic inflammation of the debrided tissue. Postoperatively, there was mild wound oozing that required bedside suture ligation. On day 19, the patient was sent to an interventional radiology centre (3 minute drive from the main hospital) for angioplasty of the left posterior tibial artery, which was unable to open the vessel distal to the medial malleolus. During the trip, he had significant pre-arrest episodes in which he lost consciousness and his mean arterial pressure dropped below 35 mm Hg. He was successfully resuscitated with inotropes during transport.
The foot wound remained infected on day 20, requiring further amputation. The family opted not to continue with amputation because the surgery would result in further functional decline and a significant reduction in quality of life. The patient was palliated and passed away on day 24 of admission.
Discussion:
The main issues arising from this case relate to:
- investigation of the source of sepsis in a patient who is immunologically and neurologically compromised from diabetes and chronic steroid use
- delay in establishing venous access
- transport of a sick ICU patient to an offsite interventional radiology site.
Collaboration between specialist teams in the rural hospital was well conducted. The surgical team continued to provide clinical input for the patient despite there being no abdominal cause of sepsis. The renal team provided a timely treatment plan for diabetic ketoacidosis and uraemia.
The diagnosis of chronic osteomyelitis/septic arthritis was challenging. The patient was medically unwell with diabetic neuropathy, renal failure and chronic steroid use, which masked the severity of his leg infection. Despite IV antibiotics, he had intermittent spikes of inflammatory markers, which are signs of unresolved sepsis. Further imaging to identify the source of infection could have been considered—specifically a new MRI scan and a progress CT scan of his chest, abdomen and pelvis. However, given his significant comorbidities and his option to decline further surgery, an early diagnosis may not have improved the final outcome.
The delay in obtaining venous access at the major rural hospital during the initial resuscitation may indicate a systematic issue when managing patients with a need for urgent venous access. The facility should have an escalation pathway, especially for an unwell patient with difficult venous access.
Finally, transporting a sick ICU patient to an offsite interventional suite requires great physician skill and complex networking to ensure patient safety. In this case, the patient lost consciousness during transport, due to his pre-arrest state, and the transporting ICU physician was skilful to avoid a major disaster. The surgical intervention of ICU patients should ideally be conducted within the hospital facility to minimise offsite transportation risks. In some instances, utilising an external interventional radiology suite may be the only solution to cover inpatient service limitations.
Clinical Lesson:
This case highlights the importance of thoroughly investigating the source of sepsis when inflammatory markers are elevated despite clinical improvement, especially in a steroid-dependent patient who has diabetic neuropathy and renal failure.
Disclaimer:
Please note that these cases are edited from ANZASM first- or second-line assessments that have been generated by expert surgeons in the field. Any recommendations relate to these cases as they were presented.
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