Proposed cutoff for fetal scalp blood lactate in intrapartum fetal surveillance based on neonatal outcomes: a large prospective observational study.

OBJECTIVE: Determination of lactate in fetal scalp blood (FBS) during labour has been recognised since the 1970s. The internationally accepted cutoff of >4.8 mmol/l indicating fetal acidosis is exclusive for the point-of-care device (POC) LactatePro™, which is no longer in production. The aim of this study was to establish a new cutoff for scalp lactate based on neonatal outcomes with the use of the StatstripLactate® /StatstripXpress® Lactate system, the only POC designed for hospital use. DESIGN: Observational study. SETTING: January 2016 to March 2020 labouring women with indication for FBS were prospectively included from seven Swedish and one Australian delivery unit. POPULATION: Inclusion criteria: singleton pregnancy, vertex presentation, ≥35+0 weeks of gestation. METHOD: Based on the optimal correlation between FBS lactate and cord pH/lactate, only cases with ≤25 minutes from FBS to delivery were included in the final calculations. MAIN OUTCOME MEASURES: Metabolic acidosis in cord blood defined as pH <7.05 plus BDecf >10 mmol/l and/or lactate >10 mmol/l. RESULTS: A total of 3334 women were enrolled of whom 799 were delivered within 25 minutes. The areas under the receiver operating characteristics curves (AUC) and corresponding optimal cutoff values were as follows; metabolic acidosis AUC 0.87 (95% CI 0.77-0.97), cutoff 5.7 mmol/l; pH <7.0 AUC 0.83 (95% CI 0.68-0.97), cutoff 4.6 mmol/l; pH <7.05 plus BDecf ≥12 mmol/l AUC 0.97 (95% CI 0.92-1), cutoff 5.8 mmol/l; Apgar score <7 at 5 minutes AUC 0.74 (95% CI 0.63-0.86), cutoff 5.2 mmol/l; and pH <7.10 plus composite neonatal outcome AUC 0.76 (95% CI 0.67-0.85), cutoff 4.8 mmol/l. CONCLUSION: A scalp lactate level <5.2 mmol/l using the StatstripLactate® /StatstripXpress® system will safely rule out fetal metabolic acidosis. TWEETABLE ABSTRACT: Scalp blood lactate <5.2 mmol/l using the StatstripLactate® /StatstripXpress system has an excellent ability to rule out fetal acidosis.

Use of Lactate ProTM2 for measurement of fetal scalp blood lactate during labor - proposing new cutoffs for normality, preacidemia and acidemia: a cross-sectional study.

OBJECTIVE: Measurement of fetal scalp blood lactate is a supplementary tool to cardiotocography in the case of a non-reassuring tracing. Several hand-held lactate meters have been launched, all with differentials in absolute values. Therefore, the reference intervals must be calculated for each device. The internationally accepted reference interval is based on measurement with Lactate ProTM with recently got out of production. The aim of this study was to propose cutoffs for normality, preacidemia, and acidemia in fetal scalp blood for Lactate ProTM2 based on the comparison of lactate values measured with Lactate ProTM and Lactate ProTM2. DESIGN: Seven hundred one fetal scalp blood samples were analyzed simultaneously. The conversion equations were retrieved from the linear regression model. On the basis of the cutoffs for Lactate ProTM cutoffs for Lactate ProTM2 were calculated. RESULTS: The conversion equations obtained were Lactate ProTM = -0.02 + 0.68 × Lactate ProTM2 (SD: -0.09-0.07 × Lactate ProTM2) and Lactate proTM2 (LP2) = 0.03 + 1.48 × Lactate ProTM (SD: 0.16 + 0.17 × Lactate ProTM). The correlation to umbilical arterial pH was identical for the two devices (r = -0.18), whereas the correlation to umbilical arterial lactate was better for Lactate ProTM than for Lactate ProTM2 (r = 0.38, respectively, r = 0.33). The correlation to umbilical arterial lactate was dependent on time from sampling to delivery. CONCLUSION: Proposed reference values for Lactate ProTM2: scalp lactate <6.3 mmol/L = normal, no indication for intervention; 6.3-7.1 mmol/L = preacidemia, repeated testing has to be considered; > 7.1 mmol/L = acidemia, expedite delivery.

Assessment of human exposure to pesticides in greenhouses and effectiveness of personal protective devices.

The exposure to pesticides in a group of workers growing vegetables in greenhouses in farms near Rimini in Italy was evaluated. The pesticides used were organophosphorus compounds, organochlorine compounds, carbamates, pyrethroids, amide and anilide derivatives. Measurements were carried out in seven greenhouses randomly selected. The environment was free of atmospheric agents which could have influenced the pesticide concentrations in the indoor air. Two types of chemical sampling were performed: environmental and personal. The latter was done in the liquid for washing hands and by means of pads applied directly to the worker's skin and to the clothes. The aim of the determination of airborne pesticide concentrations was to evaluate mean environmental exposure to pesticides in the sprayed areas. The sampling went on from a fixed point during the entire spraying period. The aim of individual sampling was to determine the active ingredients as contaminants. The values obtained showed a risk of exposure for the greenhouse personnel working without using personal protective devices (masks, gloves and waterproof clothes), considering that pesticides could be absorbed through the skin in between the spraying intervals.