Abdominal Ultrasound: Severe Malaria

Abdominal ultrasound is a rapid, radiation-free bedside tool in severe malaria used to quantify hepatosplenomegaly, assess for splenic complications and evaluate causes of jaundice or abdominal pain. It is particularly valuable in resource-limited endemic settings where portable machines allow assessment of critically ill or unstable patients. Ultrasound findings are non-specific but help gauge disease burden and detect potentially catastrophic splenic rupture or infarction.

Indications

Assessment of hepatosplenomegaly in severe or chronic malaria
Left upper quadrant pain or shoulder-tip pain suggesting splenic infarct or rupture
Jaundice and abnormal liver function (malarial hepatopathy versus other causes)
Suspected splenic rupture with haemodynamic instability (FAST assessment)
Evaluation of hyperreactive malarial splenomegaly and its complications
Baseline and follow-up of organ size during treatment and recovery

Contraindications & Cautions

No absolute contraindications; ultrasound is safe, non-ionising and repeatable
Safe in pregnancy and children
Operator dependence and bowel gas may limit assessment; overlying dressings or subcutaneous emphysema degrade images
Do not delay resuscitation of a haemodynamically unstable patient for a formal study; use bedside FAST first

Patient Preparation

Ideally fasting 4-6 hours to reduce bowel gas and distend the gallbladder, but not required in emergencies
Supine positioning; right and left lateral decubitus and coronal flank views optimise spleen and kidney assessment
Deep suspended inspiration to bring liver and spleen below the costal margin
Explain the examination and obtain verbal consent
Have the patient point to the site of maximal tenderness to guide focused scanning

Technique & Parameters

Curvilinear low-frequency transducer (2-5 MHz) for adults; higher frequency in small children
Measure spleen craniocaudal length in the coronal plane (normal adult <13 cm) and record maximal dimension
Measure liver span in the right mid-clavicular line (normal <15-16 cm) and assess parenchymal echogenicity
Systematically scan the gallbladder, biliary tree and both kidneys
Interrogate for free intraperitoneal fluid in Morrison's pouch, splenorenal recess and pelvis (FAST windows)
Colour and spectral Doppler of the splenic parenchyma and portal/splenic veins when infarct or portal hypertension is suspected

Systematic Review

Spleen: size, echotexture, focal lesions, subcapsular or perisplenic collection
Liver: size, echogenicity, surface contour, focal lesions and biliary dilatation
Gallbladder wall thickness and lumen (oedema, sludge)
Portal and splenic veins: patency, diameter and flow direction on Doppler
Kidneys: size, corticomedullary differentiation and hydronephrosis (blackwater fever, AKI)
Free fluid in all peritoneal recesses and pleural spaces
Retroperitoneum and pancreas as far as gas permits

Key Findings & Significance

Splenomegaly (>13 cm): reflects disease activity and hyperreactive malarial splenomegaly
Hepatomegaly with increased periportal/parenchymal echogenicity: malarial hepatopathy
Wedge-shaped peripheral hypoechoic non-enhancing region: splenic infarct
Perisplenic or free intraperitoneal fluid with a heterogeneous spleen: splenic rupture (surgical emergency)
Gallbladder wall oedema and periportal cuffing as non-specific inflammatory changes
Renal enlargement or altered echogenicity in malarial acute kidney injury

Differential Considerations

Massive splenomegaly: chronic/hyperreactive malaria, schistosomiasis, visceral leishmaniasis, lymphoma, haemoglobinopathy
Hepatomegaly with bright liver: malarial hepatopathy, viral hepatitis, steatosis, congestion
Splenic hypoechoic lesion: infarct, abscess, lymphoma, cyst
Free fluid with instability: splenic rupture versus other haemoperitoneum
Jaundice with dilated ducts: obstructive cause rather than haemolytic/hepatocellular malaria
Splenomegaly with portal vein dilatation: portal hypertension from schistosomiasis or chronic liver disease

Pearls & Pitfalls

An enlarged spleen is fragile - correlate with platelet count and coagulopathy before any intervention
Splenic rupture may be spontaneous and can present with minimal trauma; low threshold for FAST in a deteriorating patient
Left pleural fluid and lower rib artefact can mimic perisplenic collection
Measure the true maximal splenic length in a single coronal plane to avoid underestimation
Serial scans document response to therapy and resolution of organomegaly
Consider co-endemic causes (schistosomiasis, kala-azar) when splenomegaly is disproportionate

Structured Report

Record spleen and liver measurements and echotexture with comparison to prior studies if available
Describe focal splenic or hepatic lesions with size, location and Doppler characteristics
State presence, volume and location of free intraperitoneal fluid
Comment on biliary tree, gallbladder and kidneys
Flag any finding requiring urgent surgical review (rupture, large infarct with collection)
Impression: correlate with parasitaemia, platelets and clinical severity; recommend follow-up imaging as appropriate

References

WHO Guidelines for the Treatment of Malaria (severe malaria)
WHO Manual of Diagnostic Ultrasound (spleen and liver)
ACR Appropriateness Criteria: Right Upper Quadrant Pain / Jaundice
Rumack CM, Diagnostic Ultrasound (spleen and liver chapters)

Educational clinical decision support only. Protocols vary by institution and equipment; always confirm with a qualified radiologist and local guidelines before clinical use.

Abdominal Ultrasound: Severe Malaria

📋 Indications

⛔ Contraindications & Cautions

🧑‍⚕️ Patient Preparation

⚙️ Technique & Parameters

🔎 Systematic Review

🩻 Key Findings & Significance

🧠 Differential Considerations

💡 Pearls & Pitfalls

📝 Structured Report

📚 References