Hyponatremia can occur with central nervous system (CNS) infections, but the frequency and severity may depend on the organism and nature of CNS involvement. In this cross-sectional study at a large Australian hospital network from 2015 to 2018, we aimed to determine the prevalence and severity of hyponatremia associated with CNS infection clinical syndromes, and the association with specific organisms. We examined the results of cerebrospinal fluid analysis from lumbar punctures performed in 184 adult patients with a serum sodium below 135 mmol/L who had abnormal cerebrospinal fluid analysis and a clinical syndrome consistent with an acute CNS infection (meningitis or encephalitis). Hyponatremia affected 39% of patients and was more severe and frequent in patients with encephalitis compared to meningitis (odds ratio = 3.03, 95% CI: 1.43–6.39, after adjusting for age). Hyponatremia was present on admission in 85% of cases. Herpes simplex virus infection was associated with the highest odds of hyponatremia (odds ratio = 3.25, 95% CI: 1.13–7.87) while enterovirus infection was associated with the lowest (odds ratio = 0.36, 95% CI: 0.14–0.92), compared to cases without an isolated organism. We concluded that the risk of hyponatremia may vary by the organism isolated but the clinical syndrome was a useful surrogate for predicting the probability of developing hyponatremia.

Background Severe rhabdomyolysis is associated with acute kidney injury, but it is unclear if patients developing rhabdomyolysis after illicit drug use have a higher risk of acute kidney injury compared to other causes. Aims To provide a descriptive analysis of patients admitted with rhabdomyolysis, with a focus on illicit drug use, and to determine if illicit drug use was an independent predictor for acute kidney injury or renal replacement therapy. Methods We conducted a 5‐year cohort study of patients admitted to Monash Health, a tertiary referral hospital network. We identified adult patients with muscle injury from ICD‐10 AM codes, serum creatine kinase level greater than 1000 U/mL, and a clinical history consistent with rhabdomyolysis. We determined the prevalence and type of illicit drug involved and determined the association between illicit drug use and renal outcomes by logistic regression. Results Of 643 patients, illicit drug use was identified in 12%. Acute kidney injury developed in 51%, and 5% required renal replacement therapy. Compared to the rest of the cohort, patients who used illicit drugs were younger and had higher peak serum creatine kinase, and developed a higher severity of acute kidney injury. In multivariable analysis, the factors associated with acute kidney injury were illicit drug use, peak creatine kinase, cardiovascular disease, concurrent sepsis and a clinically‐evident pressure injury. Chronic kidney disease and need for fasciotomy were additional risk factors for renal replacement therapy. Conclusions Illicit drug use was associated with acute kidney injury and renal replacement therapy independent of creatine kinase levels.

Abnormal liver function tests are commonly observed with rhabdomyolysis, but the nature of this association is not fully defined. This study aims to determine the functional relationship between serum creatine kinase, as a marker of rhabdomyolysis severity, and liver biochemistry. We used linear regression to model the relationship between liver biochemistry and peak serum creatine kinase. A total of 528 patients with a median age of 74 years were included. The distribution of creatine kinase, bilirubin, alkaline phosphatase, alanine aminotransferase, and γ-glutamyl transferase were significantly skewed, and these variables were log-transformed prior to regression. There was a positive linear correlation between log-alanine aminotransferase and log-creatine kinase. In the multiple regression analysis, log-creatine kinase, age, acute kidney injury stage, and chronic liver disease were independently associated with log-alanine aminotransferase. This model explained 46% of the variance of log-alanine aminotransferase. We found no correlation between the log-creatine kinase and the log-bilirubin, log-alkaline phosphatase, or log-γ-glutamyl transferase. Serum alanine aminotransferase was not associated with inpatient mortality but a higher creatine kinase-alanine aminotransferase ratio was associated with lower odds of mortality. In conclusion, an isolated elevation in alanine aminotransferase can occur in rhabdomyolysis, and it may be possible to anticipate the level of increase based on the peak creatine kinase.