Fibrinogen levels in severe trauma: A preliminary comparison of Clauss Fibrinogen, ROTEM Sigma, ROTEM Delta and TEG 6s assays from the FEISTY pilot randomised clinical trial.

OBJECTIVE: To describe the relationships between different methods of measuring functional fibrinogen levels in severely injured, bleeding trauma patients across multiple timepoints during hospitalisation. METHODS: In 100 adult trauma patients enrolled in the FEISTY pilot randomised clinical trial at four tertiary trauma centres in Australia, blood samples were collected prospectively. Consistency of agreement was calculated, comparing functional fibrinogen levels measured by four methods - ROTEM® Delta and Sigma FIBTEM A5, TEG® 6s CFF MA, and gold-standard Clauss Fibrinogen. RESULTS: Comparing the ROTEM® Delta and new-generation ROTEM® Sigma machine, consistency of agreement for FIBTEM A5, measured by calculating intraclass correlation coefficients (ICCs), was ≥0.73 across all analysed timepoints, with mean differences (Sigma minus Delta) of 0.10-3.57 mm. Corresponding values comparing the ROTEM® Sigma FIBTEM A5 and TEG® 6s CFF MA were ICC = 0.55-0.82 and ICC = 4.69-7.97 (CFF MA minus A5). Comparing ROTEM® Sigma FIBTEM A5 and Clauss Fibrinogen Analysis (CFA), among statistically significant simple linear regression models, R2 was 0.25-0.67, and comparing TEG® 6s CFF MA and CFA (CFA) 0.65-0.82, although not all differences were significant with the latter comparison. Relationships across all timepoints combined were Clauss Fibrinogen (CF) (g/L) = 0.21𝑥 + 0.004 (where 𝑥 = ROTEM® Sigma FIBTEM A5 in mm) and (g/L) = 0.16𝑥 - 0.06 (where 𝑥 = TEG® 6s CFF MA in mm). CONCLUSIONS: The present study revealed acceptable agreement between four different assays measuring functional fibrinogen, with current- and previous-generation ROTEM® machines (Sigma, Delta) performing similarly measuring functional fibrinogen via FIBTEM assay. This suggests that haemostatic resuscitation algorithms designed for the ROTEM® Delta can be applied to the ROTEM® Sigma to guide fibrinogen replacement.

Profound Hypokalaemia Resulting in Maternal Cardiac Arrest: A Catastrophic Complication of Hyperemesis Gravidarum?

We present a case of a 39-year-old G8P6 Pacific Islander woman who at 15+5 weeks' gestation had an out-of-hospital cardiac arrest secondary to profound hypokalaemia which was associated with severe hyperemesis gravidarum (HG). Her clinical course after arrest was complicated by a second 5-minute cardiac arrest in the Intensive Care Unit (ICU) (pre-arrest potassium 1.8), anuric renal failure requiring dialysis, ischaemic hepatitis, and encephalopathy and unfortunately fetal demise and a spontaneous miscarriage on day 2 of admission. Despite these complications, she was discharged home 4 weeks later with a full recovery. Following a plethora of inpatient and outpatient investigations, the cause of her cardiac arrest was determined to be profound hypokalaemia. The hypokalaemia was presumed second to a perfect storm of HG with subsequent nutritional deficiencies causing electrolyte wasting, extracellular fluid (ECF) volume reduction, and activation of the renin-angiotensin-aldosterone axis (RAAS). This combined with the physiological changes that promote potassium wasting in pregnancy including volume expansion, increased renal blood flow, increased glomerular filtration rate, and increase in cortisol contributed to the patient having a profoundly low total body potassium level. This diagnosis is further strengthened by the fact that her pre- and post-pregnancy potassium levels were within normal limits in the absence of supplementary potassium. This case highlights the potentially life-threatening electrolyte imbalances that can occur with HG and the importance of recognising the disease, comprehensive electrolyte monitoring, and aggressive management in pregnancy.