AM S J
Review Article
Is plasmapheresis the optimal treatment option for acute pancreatitis secondary to hypertriglyceridemia? A systematic review Mohammad Rehmanjan Fourth Year Medicine (Undergraduate) University of Western Sydney
Mohammad is pursuing a career in paediatric neurosurgery. He has strong clinical research interests and is currently undertaking an embedded honours program looking at somatotopic distortion in stroke patients. He envisions himself as making a difference both as a clinician and an academic.
Background: Hypertriglyceridemia is an uncommon cause of acute pancreatitis, which is a life-threatening illness. Conventional management involves fasting, lipid-lowering medication, insulin and heparin. Plasmapheresis is an approach which is used occasionally to achieve rapid lowering of triglyceride levels in patients where conventional management is unsuccessful. It is currently unclear whether plasmapheresis improves outcome in patients with hypertriglyceridaemia-induced pancreatitis. Aim: A literature review and critical analysis was conducted to assess the effectiveness of plasmapheresis in improving patient outcomes in patients with acute pancreatitis secondary to hypertriglyceridemia Methods: The PICO model (Population, Intervention, Comparator, Outcomes) was used to synthesise a research question. Thereafter, a search was conducted through the Scopus database (includes complete MEDLINE coverage) applying the terms ‘plasmapheresis’ OR ‘plasma exchange’ OR ‘lipid apheresis’ AND ‘pancreatitis’ AND ‘hypertriglyceridemia’ OR ‘hyperlipidaemia’ OR ‘hyperlipidemia’. Article titles and/or abstracts were screened for relevance to the topic. Original research articles assessing the efficacy of plasmapheresis in hypertriglyceridaemia-induced pancreatitis were included. Results: To date, no randomised controlled trials have been published assessing the efficacy of plasmapheresis in this population. Two retrospective primary research studies were identified. Both studies demonstrated a rapid reduction in triglyceride levels following plasmapheresis in the magnitude of 65.8-80%. The studies showed no significant clinical benefit in terms of mortality and morbidity, but were limited by small sample size and study design. Conclusion: Current evidence demonstrates that plasmapheresis in the setting of hypertriglyceridemia-induced pancreatitis reduces triglyceride levels by 46-80%. [1] However there is insufficient data to suggest a beneficial effect on clinical outcomes. Well-designed prospective studies with adequate follow-up are required to elucidate whether plasmapheresis is associated with reduced morbidity and mortality in this population.
Introduction
morbidity and mortality. Current management includes fasting, lipidlowering medication (such as fenofibrate), and insulin and heparin, used to ‘accelerate lipoprotein lipase activity’. [2,4] These interventions have shown limited efficacy in reducing inflammation and lifethreatening complications associated with severe acute pancreatitis. Novel therapies are needed to improve patient outcomes. [5] Plasmapheresis is defined as ‘removing the plasma and replacing it with donor plasma or a plasma substitute’. [6] The term plasmapheresis is used interchangeably with the term ‘therapeutic plasma exchange’. The use of plasmapheresis in patients with hypertriglyceridemia can be traced back to a case report in 1978. [3] However, it is not widely utilised in this patient population at present. Given that plasmapheresis provides rapid removal of the triglycerides responsible for underlying inflammation in hypertriglyceridemia-induced pancreatitis, it is expected that this intervention may prove highly effective in reversing this sub-type of acute pancreatitis. The aim of this review was to assess the effectiveness of plasmapheresis in achieving positive patient outcomes (as per Table 1) in patients with acute pancreatitis secondary to hypertriglyceridemia. Table 1. PICO model.
Hypertriglyceridemia is an uncommon cause of acute pancreatitis, accounting for 1.3-3.8 % of cases with an incidence of 18/100,000 per year in the United States of America. [1,2] Primary (genetic) and secondary causes, such as uncontrolled diabetes mellitus, hypothyroidism, alcohol, obesity, certain medications, and pregnancy, are associated with hypertriglyceridemia-induced pancreatitis. [1,3] The mechanism for severe hypertriglyceridemia-inducing pancreatitis remains unclear, [3] although triglyceride levels exceeding 10 mmol/l (1000 mg/dl) can trigger a bout of pancreatitis. [3,4] One postulated theory involves the idea that pancreatic lipase hydrolyses excess triglycerides to produce free fatty acids around the pancreas. These free fatty acids can damage the pancreatic acinar cells and pancreatic vascular endothelium, resulting in ischaemia and inflammation. The acidic environment can further amplify the free fatty acid toxicity in a vicious cycle. [3,4]
Population
Patients with acute pancreatitis secondary to hypertriglyceridemia
Intervention
Plasmapheresis/therapeutic plasma exchange
Comparator
Conventional treatment for hypertriglyceridemia-induced pancreatitis (as defined above)
Outcomes
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Hypertriglyceridemic pancreatitis is a life-threatening illness with a mortality rate of 7-30%. [5] Complications include sepsis, pancreatic necrosis, abscess formation and renal insufficiency; which account for the high mortality seen in this disease. [3] Optimal management of hypertriglyceridemia-induced pancreatitis is essential to reduce
Methods
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Symptomatic relief Complications secondary to acute pancreatitis Mortality Lowering of triglyceride levels
The PICO model was used to synthesise the research question. [7] Search Methodology The literature search was conducted on Scopus, which is one of the
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