Management of severe malaria in the intensive care unit

Fluid therapy for severe malaria

Fluid therapy is an important supportive measure for patients with severe malaria. Patients with severe malaria usually have normal cardiac index, vascular resistance, and blood pressure and a small degree of hypovolaemia due to dehydration. Cell hypoxia, reduced kidney function, and acidosis result from microcirculatory compromise and malarial anaemia, which reduce tissue oxygenation, not hypovolaemia. Hence, aggressive fluid loading does not correct acid-base status, enhance kidney function, or improve patient outcomes, and it risks complications such as pulmonary oedema. Individualised conservative fluid management is recommended in patients with severe malaria. Physical examination and physiological indices have limited reliability in guiding fluid therapy. Invasive measures can be more accurate than physical examination and physiological indices but are often unavailable in endemic areas, and non-invasive measures, such as ultrasound, are mostly unexplored. Research into reliable methods applicable in low-resource settings to measure fluid status and response is a priority. In this Review, we outline the current knowledge on fluid management in severe malaria and highlight research needed to optimise fluid therapy and improve survival in severe malaria.

Malaria in the Intensive Care Unit

Most cases of severe malaria are caused by Plasmodium falciparum. Severe malaria is characterized by severe organ dysfunction. Both peripheral smear examination and rapid diagnostic test have a role in the diagnosis. Parenteral artesunate is clearly the drug of choice for the management of severe malaria. Parenteral artesunate should always be followed up with ACT.

Most of the complications of severe malaria require supportive care only. The role of exchange transfusions in the management of severe malaria is questionable in the postartesunate era. Malaria in pregnancy can be quite severe and artesunate is now the drug of choice for all three trimesters. Vivax malaria is being increasingly recognized as a cause of severe malaria. The cause for this increased virulence is still not clear. Management of severe vivax malaria is similar to that of severe falciparum malaria.

How to cite this article: Hegde A. Malaria in the Intensive Care Unit. Indian J Crit Care Med 2021;25(Suppl 2):S127–S129.

Optimizing the Intensive Care Treatment of Severe and Complicated Plasmodium falciparum Malaria in Nonimmune Patients

This study analyses the intensive care treatment of 48 patients admitted to the Intensive Care Unit (ICU) at the Infectious Diseases Clinical Hospital No. 2, Moscow, Russia, between 2007 and 2019, with a severe and complicated form of P. falciparum malaria (B50.8 ICD 10). Objective. The aim of this study was to improve the intensive care treatment for severe and complicated P. falciparum malaria. The treatment strategy implemented was aimed at preventing ischaemia-reperfusion injury to organs, as well as haemorrhagic complications. The ICU Case Management Protocol set up indications for transferring patients to the ICU which provide preventive (prior to the development of renal failure) application of extracorporeal hemocorrection methods (continuous venous-venous hemodiafiltration and plasmapheresis in a plasma exchange mode) and mechanical ventilation under a medically induced coma, given impaired consciousness as the initial symptom of patients. Results. Successful treatment outcome in a majority of the patients (93.8%), shorter ICU length of stay (6.67 ± 1.9 days as compared to 94 ± 1.6 before introduction of the protocol), a median parasite clearance time of 37.50 hours (95% CI 36.21-38.18), and a reduced mortality rate from 29.1% to 6.25% support the efficacy of the ICU protocol in managing severe and complicated P. falciparum malaria.

Malaria Pathogenesis

In the mosquito-human life cycle, the six species of malaria parasites infecting humans (Plasmodium falciparum, Plasmodium vivax, Plasmodium ovale wallickeri, Plasmodium ovale curtisi, Plasmodium malariae, and Plasmodium knowlesi) undergo 10 or more morphological states, replicate from single to 10,000+ cells, and vary in total population from one to many more than 10⁶ organisms. In the human host, only a small number of these morphological stages lead to clinical disease and the vast majority of all malaria-infected patients in the world produce few (if any) symptoms in the human. Human clinical disease (e.g., fever, anemia, coma) is the result of the parasite preprogrammed biology in concert with the human pathophysiological response. Caveats and corollaries that add variation to this host-parasite interaction include parasite genetic diversity of key proteins, coinfections, comorbidities, delays in treatment, human polymorphisms, and environmental determinants.

Intensive care in severe malaria: Report from the task force on tropical diseases by the World Federation of Societies of Intensive and Critical Care Medicine

Severe malaria is common in tropical countries in Africa, Asia, Oceania and South and Central America. It may also occur in travelers returning from endemic areas. Plasmodium falciparum accounts for most cases, although P vivax is increasingly found to cause severe malaria in Asia. Cerebral malaria is common in children in Africa, manifests as coma and seizures, and has a high morbidity and mortality. In other regions, adults may also develop cerebral malaria but neurological sequelae in survivors are rare. Acute kidney injury, liver dysfunction, thrombocytopenia, disseminated intravascular coagulopathy (DIC) and acute respiratory distress syndrome (ARDS) are also common in severe malaria. Metabolic abnormalities include hypoglycemia, hyponatremia and lactic acidosis. Bacterial infection may coexist in patients presenting with shock or ARDS and this along with a high parasite load has a high mortality. Intravenous artesunate has replaced quinine as the antimalarial agent of choice. Critical care management as per severe sepsis is also applicable to severe malaria. Aggressive fluid boluses may not be appropriate in children. Blood transfusions may be required and treatment of seizures and raised intracranial pressure is important in cerebral malaria in children. Mortality in severe disease ranges from 8 to 30% despite treatment.

Pulmonary manifestation of Plasmodium falciparum malaria: Case reports and review of the literature

Pulmonary complications, including acute respiratory distress syndrome (ARDS), are well described in P. falciparum (PF) and to a lesser extent in other malaria species. In non-endemic areas, malaria diagnosis may be overlooked; if a thorough travel history is not obtained on all patients with acute febrile illness. Three patients with malaria associated respiratory distress were admitted to our intensive care unit. The diagnosis was delayed; however, all patients received artesunate and intensive therapy with a satisfactory outcome. One patient presented with respiratory disease while the others developed ARDS during or following appropriate therapy. Similarly, level of parasitemia was variable ranging from undetectable to over 5%. Variability in timing and severity of illness is exciting and gives emphasis to the different pathological processes contemplated in this complication.

Perioperative considerations of the patient with malaria

Purpose

Malaria is a life-threatening infectious disease caused by the Plasmodium parasite. Increased global travel has resulted in an escalation in the number of imported cases seen in developed countries. Patients with malaria may present for surgery in both endemic and non-endemic countries. This article reviews the perioperative considerations when managing patients with malaria.

Source

A literature review of anesthesia, perioperative care, and malaria-related articles was performed using the MEDLINE^®, EMBASE™, and Web of Science databases to identify relevant articles published in English during 1945-2014. Of the 303 articles matching the search criteria, 265 were excluded based on title and abstract. Eleven of the remaining 38 articles were relevant to anesthesia/perioperative care, and 27 articles were identified as having direct relevance to critical care medicine.

Principal findings

The majority of imported malaria cases are caused by the falciparum species, which is associated with the greatest degree of morbidity and mortality. Various organ systems may be impacted as a consequence of changes in the structure and function of parasitized erythrocytes. Preoperative assessment should focus on establishing the species of malaria, the severity of disease, assessing the degree of end-organ impairment, and initiating treatment of malaria prior to surgery. Intravenous artesunate is the treatment of choice for severe falciparum malaria. Quinine is a second-line agent but has a narrow therapeutic index and particularly hazardous side effects. Intraoperatively, attention should focus on fluid management, dynamics of cerebral blood flow, and avoidance of hypoglycemia. Postoperative care of severe cases should ideally take place in a critical care unit as there may be ongoing requirements for multi-organ support, including renal replacement therapy, ventilation, and/or inotropic support. The safety of neuraxial anesthesia has not been well studied in the setting of malaria.

Conclusions

Malaria remains one of the most devastating infectious diseases worldwide. Multiple organ systems can be impacted as a consequence of changes in structure and function of parasitized erythrocytes. Safe perioperative management requires a sound knowledge of all these potential system effects.