Malaria and postoperative fever

Sir, In the early postoperative period some patients develop fever. One such case of high-grade fever with chills and rigors is described which was diagnosed and treated as malaria. In patients with chronic malaria, the spleen is a reservoir of the malarial parasite. In response to stress, it is hypothesized that the spleen contracts and releases the parasite into the circulation. This probably explains the surprisingly common postoperative fever in malaria endemic areas. This may also be seen in people who have traveled to such areas. A 25-year-old laborer fell from a bicycle and sustained a closed injury to his left elbow. Clinical and radiological evaluation revealed an intrarticular fracture of his lower humerus and the olecranon. He was otherwise healthy with no significant surgical history but had previously suffered recurrent attacks of malarial fever. He was now afebrile with a swollen and tender elbow covered with intact skin. Systemic examination was normal and there was no palpable enlargement of the spleen. Laboratory investigations were unremarkable and he planned to undergo elective open reduction and internal fixation of the humerus and ulna. The surgery was performed under general anesthesia and lasted 3 h. The patient remained normothermic and hemodynamically stable throughout the surgery. No blood was transfused and intravenous fluids were continued postoperatively. He made a satisfactory recovery and was shifted to the ward fully awake and pain free. Six hours after the surgery he developed fever with temperature of 39 C and had associated chills and rigors. Clinical examination, including that of the wound, chest and intravenous access site, failed to reveal any focus of infection. He was treated with tepid sponging and antipyretics. Blood tests performed showed a normal leukocyte count and the peripheral smear was negative for the malarial parasite. Since his fever persisted he was treated with a course of antimalarials (Chloroquine 600 mg p.o. stat. followed by 300 mg p.o. after 6 h and then 150 mg p.o. twice daily for 3 days). He had another spike of 38 C after 1 h and then became afebrile. He remained afebrile till he was discharged after an uneventful postoperative period of 10 days. In malaria endemic areas recurrent pyrexia is often due to re-infections or relapses of malaria. A study (1) suggests that the prevalence rate of malaria increases from 8 before surgery to 15 after surgery in the tropics. The mechanism of sequestration of the malarial parasite in the spleen following repeated bouts of malaria or prolonged untreated infection resulting in hypermalarial splenomegaly syndrome (HMS) has been described (2). The role of the spleen in contributing to the circulating blood volume has been demonstrated in a study on human subjects undergoing hemodialysis, using radioactive tagged RBCs, and the results suggest that contraction of the splanchnic and the splenic vascular beds occurs during fluid removal associated with hemodialysis (3). Bakovic et al. (4), using ultrasonic monitoring of the spleen amongst divers and splenectomised untrained persons, studied the reduction in spleen size in breath-hold apnea, and suggested that active contraction of the spleen may contribute to prolongation of successive, briefly repeated apnea attempts. Active contraction of the spleen in response to both hypovolemia and hypoxia has been demonstrated in animals (5). This case is described in an endemic area for malaria, where many patients with past history of malaria may have the parasite sequestered in the spleen. In the perioperative period in response to stress, hypoxia or hypovolemia, the spleen may contract and release the parasite resulting in pyrexia in the postoperative period. Therefore malaria should be considered an important cause of high-grade fever in the early postoperative period for patients living in or who have traveled to malaria endemic areas provided other causes such as wound infection, sepsis or allergic reactions have been ruled out.