Clinical scoring demonstrates the greater predictive capability for melioidosis pneumonia

The authors have introduced a novel computed tomography (CT) scoring system for staging melioidosis pneumonia and predicting disease progression (1). They analyzed CT findings of a cohort of 97 patients and developed a model yet to be validated for the clinical progression. These need further discussion in real-world practicability and clinical relevance. We have concerns about how this model can effectively benefit clinicians and whether its implementation is feasible. There are numerous uncertainties which require further deliberation.

The authors compared the radiological scoring of coronavirus disease 2019 (COVID-19) pneumonia. In cases of COVID-19 or viral pneumonia, most lobes are affected by secondary pulmonary lobule (SPL) involvement. The SPL is the smallest structural unit of the lung, separated by interlobular septa that house pulmonary veins, lymphatics, and connective tissue. Even for viral pneumonia, which involves most of the lobes of the lungs, the most recent World Health Organization (WHO) guidelines emphasize the limited evidence available to inform the use of imaging in treating patients with COVID-19 (2).

However, this is not true for bacterial pneumonia caused by Burkholderia Pseudomallei (3). Melioidosis is defined as “classically characterized by pneumonia and multiple abscesses, with a mortality rate” (4). The major clinical presentations include the extensive spread of localized abscesses in major organs like the spleen, kidney, liver, pleura, soft tissue, brain, and lung, in addition to pneumonia and acute septicemia in some cases.

Chest radiography and extent of organ involvement, as shown by CT scans of patients who present to the emergency/hospital, have a role in deciding admission to the intensive care unit (ICU) when waiting for the results of melioidosis culture. Due to radiation hazards and nephrotoxicity of using dye (when the patient is on intravenous ceftazidime or meropenem), repeat CT is not ethically justified. Because melioidosis is a multisystemic disease, unlike COVID-19, primarily viral pneumonia, it needs a whole-body CT scan.

Melioidosis is a disease common in tropical and subtropical countries. Approximately 85% of sepsis cases worldwide occur in low- and middle-income countries that have restricted access to resources (5) and where repeat CT is not ordinarily affordable in most of the cases. In an infective condition, do we need serial CT (using nephrotoxic dye with concurrent nephrotoxic drug) and thus elevated radiation hazards? These can be assessed by chest radiograph.

Again, the disease course is highly variable, with an incubation period of 1–21 days, but it can also be as long as years. Most of the cases are chronic at the time of presentation (more than 2 months). Therefore, instead of repeated CT scanning, creating a precision medicine strategy, such as incorporating microbiological confirmation, is crucial for enhancing the clinical management of melioidosis. Key factors to consider include a significant rate of microbiological confirmation in healthcare facilities with microbiological resources, a substantial disease burden in endemic regions, and a heightened mortality rate. Early diagnosis and the absence of appropriate antibiotics are important predictors of the outcome rather than CT staging; if taken after a reasonable interval, it can predict radiological resolution in the era of antibiotic treatment (as all the patients are treated) irrespective of the severity. In all pneumonia, the clinical resolution precedes radiological resolution (lags behind), of which it takes longer to resolve, and the shadow due to the destruction of the lung parenchyma, later healed with the cavity, the opacity may not have a full resolution after the treatment, creating further confusion. As the German poet Bertolt Brecht said: ‘I have much workload, I am preparing my next bias’.

Escalation or de-escalation of antibiotics and level of care, particularly in the ICU, are based on the capability to assess the severity of pulmonary infection and culture conversion. However, radiological records are needed to document the improvement over time. As it is a treatable bacterial disease, we do not expect any deterioration after the early diagnosis and the use of antibiotics.

Clinical improvement depends on comorbidities like diabetes mellitus, immune status, and other factors. Good glycemic control and appropriate antibiotics are essential to reduce the progression of melioidosis. Having a thorough understanding of the prognosis of melioidosis is essential in the clinical setting. Accurate prognostication enables healthcare providers to effectively communicate with patients regarding the anticipated outcomes of their acute illness. Additionally, being able to assess the likelihood of serious adverse events, such as severe medical complications or mortality, can aid healthcare providers in making informed decisions regarding initial treatment strategies, including determining the most suitable treatment location, level of medical intervention required (e.g., medical ward vs. ICU), and the extent of diagnostic testing and antibiotic therapy needed (6).

There are many predictive and severity scores for bacterial pneumonia, like CURB65, pneumonia severity index (PSI), SMART-CO, etc. There is no system with which the severity and progression are calculated based on the clinical factors rather than dependent on co-morbidity and treatment approach.

Assessment of oxygen levels through pulse oximetry, vital sign monitoring, and analysis of biochemical parameters are essential factors that can significantly enhance the predictive accuracy of a severity scoring system.

Michael Fine and colleagues pioneered the initial scoring system for community-acquired pneumonia (CAP), known as the PSI. This index was designed to predict mortality rates and identify patients who have a low risk of mortality, suggesting that they may be able to be treated without requiring hospitalization (7).

Due to the intricate nature of the PSI, it led to the creation of an additional scoring system known as CURB-65 (an abbreviation for Confusion, Urea, Respiratory rate, Blood pressure, and age equal to or greater than 65) by the British Thoracic Society (8).

The other scoring systems, including the SMART-COP method developed in Australia, have been introduced. SMART-COP stands for Systolic blood pressure, multi-lobar infiltrates, albumin, respiratory rate, tachycardia, confusion, oxygen, and pH (9).

The above (7-9) popularly validated pneumonia scoring systems have not incorporated a CT score. Each of the current scoring systems possesses strengths and weaknesses. Key benefits include the ability to predict mortality risk, identify progressive severe complications, and potential cost savings by efficiently allocating hospital resources to lower the risk of patients. Additionally, these scores aid in the early identification of critically ill patients, facilitating prompt referral to the ICU for timely interventions.

In conclusion, while all the scores are valuable tools, they cannot replace clinical assessment, clinical judgment, and microbiologist’s diagnosis and support during the long course of antibiotic management. The optimal approach to treating melioidosis pneumonia always involves experienced physicians (smart doctors, not SMART-COP) who can utilize their clinical expertise to address the unique needs of individual patients and utilize these scores as additional resources in making informed decisions for the cure and care of the patients.

Appendix 1: Response to “clinical scoring demonstrates the greater predictive capability for melioidosis pneumonia”

Acknowledgments

Funding: None.

Footnote

Conflicts of Interest: Both authors have completed the ICMJE uniform disclosure form (available at https://qims.amegroups.com/article/view/10.21037/qims-24-1327/coif). The authors have no conflicts of interest to declare.

Ethical Statement: The authors are accountable for all aspects of the work in ensuring that questions related to the accuracy or integrity of any part of the work are appropriately investigated and resolved.

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