Journal of clinical monitoring and computing
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J Clin Monit Comput · Apr 2024
FiO2 prediction formula during low flow oxygen therapy in an adult model: a bench study.
During low-flow oxygen therapy, the true value of inspired oxygen fraction (FiO2) is generally unknown. Knowledge of delivered FiO2 values may be useful as well as to adjust oxygen therapy, as well as to predict patient deterioration. This study proposes a New FiO2 Prediction Formula (NFiO2) for low-flow oxygenation and compares its predictive value to precedent formulas. ⋯ Bias and limits of agreement between predicted FiO2 and benchtop FiO2 highlighted consistent differences between different FiO2 prediction formulas. The NFiO2 and the Duprez Formula 2018 seemed to be the most accurate formulas, followed by the Vincent Formula, and lastly the Shapiro Formula. A New FiO2 Prediction Formula was developed using clinical readily available variables (RR and O2 Flow rate) which showed good accuracy in predicting FiO2 during oxygenation at low flow.
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J Clin Monit Comput · Apr 2024
Observational StudyAssessment of changes in blood volume during lower body negative pressure-induced hypovolemia using bioelectrical impedance analysis.
Lower body negative Pressure (LBNP)-induced hypovolemia is simulating acute hemorrhage by sequestrating blood into lower extremities. Bioelectrical Impedance Analysis (BIA) is based on the electrical properties of biological tissues, as electrical current flows along highly conductive body tissues (such as blood). Changes in blood volume will lead to changes in bioimpedance. This study aims to study changes in upper (UL) and lower (LL) extremities bioimpedance during LBNP-induced hypovolemia. ⋯ During LBNP-induced hypovolemia, there were reciprocal changes in UL&LL bioimpedance. These changes reflected hemodynamic compensatory mechanisms to hypovolemia.
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J Clin Monit Comput · Apr 2024
Randomized Controlled TrialRenal medullary oxygenation during laparoscopic vs open surgery: the impact of blood pressure management-a pilot randomized controlled trial.
The impact of blood pressure targets and surgical approach (laparoscopic or open) on continuous urinary oxygenation (PuO2), a validated surrogate of renal medullary PO2, during general surgery, is unclear. We aimed to assess the effects of different blood pressure targets and surgical procedures on PuO2. We randomized patients receiving either laparoscopic or open surgery into two mean arterial pressure (MAP) target groups: usual MAP or a high MAP. ⋯ Surgical approach and intraoperative blood pressure targets significantly impact urinary oxygenation. Further studies with larger sample sizes are needed to confirm these findings and understand their potential clinical implications. Registration number: ACTRN12623000726651; Date of registration: 05/07/2023 (retrospectively registered).
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J Clin Monit Comput · Apr 2024
Racial effects on masimo pulse oximetry: impact of low perfusion index.
Evaluate the SpO2-SaO2 difference between Black and White volunteer subjects having a low perfusion index (Pi) compared to those having a normal Pi. ⋯ Masimo SET® pulse oximeters with RD SET® sensors are accurate for individuals of both Black and White races when Pi is normal, as well as during conditions when Pi is low. The ARMS for all conditions studied is well within FDA standards. This study was conducted in healthy volunteers during well-controlled laboratory desaturations, and results could vary under certain challenging clinical conditions.
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J Clin Monit Comput · Apr 2024
Pressure-adjusted venting eliminates start-up delays and compensates for vertical position of syringe infusion pumps used for microinfusion.
Microinfusions are commonly used for the administration of catecholamines, but start-up delays pose a problem for reliable and timely drug delivery. Recent findings show that venting of the syringe infusion pump with draining of fluid to ambient pressure before directing the flow towards the central venous catheter does not counteract start-up delays. With the aim to reduce start-up delays, this study compared fluid delivery during start-up of syringe infusion pumps without venting, with ambient pressure venting, and with central venous pressure (CVP)-adjusted venting. ⋯ At 360 s after start-up 72% to 92% of expected fluid volumes were delivered without venting, 46% to 82% with ambient pressure venting and 96% to 99% with CVP-adjusted venting. CVP-adjusted venting demonstrated consistent results across vertical pump placements (p = 0.485), whereas the other methods had significant variances (p < 0.001 for both). In conclusion, CVP-adjusted venting effectively eliminates imprecise drug delivery and start-up delays when using microinfusions.