Prevalence of pseudonatremia in a clinical laboratory - role of the water content.

BACKGROUND: Sodium concentration is a frequently used marker to discriminate between differential diagnoses or for clinical follow-up. Pseudonatremia, as a result of indirect ion-selective electrode (ISE) measurements in automated chemistry analyzers, can lead to incorrect diagnosis and treatment. We investigated whether the estimated water content, based on total protein and lipid concentrations, can be used to reduce diagnoses of pseudonatremia. METHODS: Indirect and direct ISE measurements of sodium were compared in blood samples from intensive care unit (ICU) (n = 98) and random non-ICU patients (n = 100). Differences between direct measurements using whole blood and lithium-heparin plasma were also determined. Water content, estimated by a linear combination of total protein and lipid concentrations, was used to correct indirectly measured sodium concentrations. The prevalence of pseudonatremia was evaluated in the ICU patient group. RESULTS: An absolute difference of 3 mmol/L was observed between direct measurements using lithium-heparin plasma and whole blood, with higher concentrations in plasma. Additionally, we observed that differences between indirect and direct measurements displayed a linear relationship with the estimated water content. The prevalence of pseudohypernatremia after indirect measurements (32%) was reduced when measurements were corrected for water content (19%). CONCLUSIONS: In critically ill patients, sodium concentrations should be preferably measured by direct measurements. Whole blood is the preferred material for these measurements. For routine sodium analyses in other patients, correction using the estimated water content appears promising in reducing the prevalence of pseudohypernatremia by indirect measurements.

Public counselling: Brazilian Pentecostal intimate performances among urban women in Mozambique.

Analysing the public character of Brazilian Pentecostal counselling sessions in urban Mozambique, this paper aims to examine the configurations of exposure through which counselling acquires and produces sociocultural forms of intimacy. During 'therapy of love' sessions held by the Brazilian Universal Church of the Kingdom of God, strict bodily acts need to be performed publicly to authorise love. Drawing on the notion of religious habitus, the paper focuses on how the performativity of Brazilian Pentecostal counselling practices responds to and shapes a public culture of love and intimacy among upwardly mobile women in urban Mozambique, and how the performative scripts converts carry out during therapy result in ambiguous relationships.