Les J, a 53-year-old builder, was referred for a mitral valve replacement for long-standing mitral stenosis. His postoperative course had been uncomplicated and he was discharged from hospital on the 14th postoperative day. He was convalescing at home when, on the 23rd postoperative day, he suddenly developed fever with chills, headache, and muscle and joint pains. He did not complain of a sore throat or respiratory symptoms. On examination his temperature was 38.5 °C, pulse 102 and irregular (atrial fibrillation), BP 120/70, and respiratory rate 22/minute. The other abnormalities were bilateral basal crepitations, mild ankle oedema, cervical lymphadenopathy and hepatomegaly. His urine had a trace of protein, blood and bilirubin. His medication was digoxin, frusemide, potassium chloride and warfarin.
Following the home visit I admitted him to hospital with the provisional diagnosis of bacterial endocarditis (foremost), infectious mononucleosis (IM) or a urinary infection. He had undergone perfusion with fresh whole blood during surgery and thus blood-transmitted infections such as IM, hepatitis A or B, malaria and brucellosis were considered possible. I took blood for routine examination, culture, heterophil antibodies and liver function tests. A mid-stream specimen of urine was sent for microscopy and culture.
His fever and other symptoms settled spontaneously after four hours and on review the following day he said he felt well and would like to go home. However, at precisely 4 pm the fever returned and it subsequently returned at 4 pm each day. His temperature would then return to 37.2 °C within four to six hours (Figure 16.1).
Fig. 16.1 Les J: graph of temperature pattern, showing a sharp rise each mid afternoon daily
The results of Les J’s investigations were as follows:
Hb 14 g/L (normal indices)
WCC 12 600 lymphocytosis, many abnormal lymphocytes
MSU—many RBCs: normal culture
Sputum culture—no pathogens isolated
Chest X-ray—mild interstitial oedema, venous congestion
ECG—atrial fibrillation, incomplete RBBB, no evidence of ischaemia
IM screening test—negative, no heterophil antibodies
Blood culture—no growth after six days
Liver function tests—abnormal (moderate elevation of enzymes)
I realised that isolating a bacterial organism on blood culture would prove difficult because of previous exposure to antibiotics for a chest infection. I consulted with his cardiologist who suggested arranging serial antibody titres for cytomegalovirus.
Les had acquired cytomegalovirus infection from the blood perfusion and his fever continued to spike in the mid-afternoon each day for about three weeks. There was no specific treatment. He eventually settled and had no long-term effects from the extraordinary infection.
DISCUSSION AND LESSONS LEARNED
Unfamiliarity with uncommon infections can be confusing. Next time around it should be easier to recognise the fever patterns.
It is still important to consider foremost the common or serious causes of cardiac postoperative fever such as bacterial endocarditis or urinary tract infection.
Previous or current exhibition of antibiotics can mask any responsible bacterial organism, making isolation on culture difficult, if not impossible. Hence antibiotics should be used judiciously in these patients.
Taking anticoagulants can cause red blood cells to appear in the urine and give the impression of urinary infection.
Cytomegalovirus infection should be suspected on clinical grounds, especially in patients who have undergone open-heart surgery or renal transplantation. It causes a febrile illness (resembling glandular fever), which often manifests as quotidian intermittent fever, spiking to a maximum in the mid-afternoon and falling to normal each day. There is usually a relative lymphocytosis with atypical lymphocytes (similar to IM) but the heterophil antibody test is negative. Liver function tests are often abnormal. Generalised lymphadenopathy and hepatomegaly are typical. Specific diagnosis can be made by demonstrating rising antibody titres. The virus can be isolated from the urine and blood.
It requires considerable skill and reassurance to convince patients to ‘sweat it out’ for up to six weeks of daily fevers, without specific medication.