. Multifactorial Encephalopathy & Hyperammonemia in Critical Illness.— Part 6

    Part 6 of 8   

Introduction

    Neurological deterioration in critically ill patients can be multifactorial, particularly when severe infection, renal dysfunction and respiratory compromise coexist. In such settings, altered consciousness may reflect overlapping septic, metabolic and respiratory contributors rather than a single isolated cause.

    This case highlights the evaluation and management of multifactorial encephalopathy and hyperammonemia in a critically ill patient with multidrug-resistant (MDR) Escherichia coli urosepsis and acute kidney injury on chronic kidney disease (AKI on CKD).

Clinical Findings

    Neurological deterioration was documented around hospital day 9 (HD9). Serial ammonia measurements showed fluctuations during the clinical course:

    These measurements provide a record of changing ammonia levels during critical illness. However, ammonia values alone cannot establish the cause of encephalopathy; they must be interpreted alongside the neurological examination and the patient's broader clinical condition.

Neuroimaging Findings

    Brain MRI documented chronic ischemic and periventricular changes, along with cerebral atrophy. No acute mass effect was reported in the available case summary.

    These findings provide background information about cerebral changes but do not, by themselves, establish the cause of the patient's acute neurological deterioration.

EEG Findings

    The electroencephalogram (EEG), performed on HD12, showed generalized bilateral theta slowing, predominantly at 5–6 Hz. No epileptiform discharges were reported.

    Generalized slowing is a nonspecific finding that can occur in diffuse cerebral dysfunction. In this case, the EEG findings needed to be considered alongside the clinical course, infection, renal dysfunction and metabolic abnormalities.

Management Documented

    The documented management approach included treatment directed at infection and metabolic disturbances, renal support, and measures to address hyperammonemia.

The case records the use of:

   

• Renal support, including hemodialysis.

   

• L-ornithine L-aspartate (LOLA).

   

• Rifaximin.

   

• Lactulose, administered orally and by enema.

 

    These interventions are reported as documented in the case material. Their inclusion does not independently establish the contribution of any single treatment to neurological changes.

Clinical Discussion

    The central clinical challenge in this case was the presence of several potential contributors to neurological deterioration at the same time. MDR E. coli urosepsis, AKI on CKD, metabolic disturbances and respiratory compromise created a complex clinical picture in which encephalopathy required a multifactorial assessment.

    The fluctuating ammonia measurements were an important part of the evaluation, but they could not be interpreted in isolation. Similarly, the MRI findings documented chronic cerebral changes, while the EEG demonstrated generalized slowing without reported epileptiform discharges. Each investigation contributed a different piece of information rather than providing a single definitive explanation.

    Renal dysfunction and severe systemic illness further complicated the assessment. Respiratory deterioration and hypercapnia were also documented during the broader clinical course, making it important to consider respiratory and metabolic contributors together when interpreting changes in consciousness.

Key Clinical Learning Points

   

• Neurological deterioration during sepsis may have multiple overlapping contributors.

   

• Ammonia trends should be interpreted alongside clinical findings and other investigations.

   

• Generalized EEG slowing is a nonspecific marker of cerebral dysfunction and must be correlated with the clinical picture.

   

• MRI and EEG provide complementary information but may not independently identify the cause of encephalopathy.

   

• Renal dysfunction, metabolic abnormalities and respiratory compromise can complicate neurological assessment in critical illness.

 

Key Takeaway

    In critical illness, altered consciousness should not be attributed to a single laboratory value or investigation without considering the broader clinical picture. Integrating neurological findings with systemic, metabolic, renal and respiratory factors is essential to a careful clinical assessment.

 

Conclusion

    This case illustrates the complexity of evaluating multifactorial encephalopathy in a critically ill patient with MDR E. coli urosepsis, AKI on CKD and respiratory compromise. Serial ammonia measurements, neuroimaging and EEG findings contributed to the assessment, while the overlapping systemic complications made interpretation challenging.

    The key lesson is the importance of integrating neurological findings with the patient's overall clinical course rather than attributing altered consciousness to a single laboratory value or investigation.

Clinical Discussion Question

Looking Ahead: Part 7 of 8

    The clinical course continues in Part 7 of this eight-part case series, exploring further challenges in managing a critically ill patient with multiple interacting complications. The next instalment will continue examining how evolving clinical findings shape assessment, treatment priorities and decision-making in complex critical care.

    Clinical Education Disclaimer: This case study is intended for medical education and clinical discussion. It does not replace individualized clinical judgment, professional medical advice or institutional protocols.