Journal of clinical monitoring and computing
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J Clin Monit Comput · Feb 2022
Randomized Controlled TrialQuantitative assessment of cytochrome C oxidase patterns in muscle tissue by the use of near-infrared spectroscopy (NIRS) in healthy volunteers.
Cytochrome C oxidase (CCO) acts as final electron acceptor in the respiratory chain, possibly providing information concerning cellular oxygenation. CCO is a chromophore with a broad absorption peak in the near-infrared spectrum in its reduced state (835 nm). However, this peak overlaps with deoxygenated haemoglobin (HHb; 755 nm) which is present in much higher concentrations. ⋯ HHb and CCO follow a significant different trend over time during the intervention period for both arterial occlusion (F = 20.645, edf = 3.419, p < 0.001) and venous stasis (F = 9.309, edf = 4.931, p < 0.001). Our data indicate that CCO concentration changes were not affected by HHb changes, thereby proving independency. Clinical trial registration: B670201732023 on June 28, 2017.
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J Clin Monit Comput · Feb 2022
Observational StudyClinical validation of a computerized algorithm to determine mean systemic filling pressure.
Mean systemic filling pressure (Pms) is a promising parameter in determining intravascular fluid status. Pms derived from venous return curves during inspiratory holds with incremental airway pressures (Pms-Insp) estimates Pms reliably but is labor-intensive. A computerized algorithm to calculate Pms (Pmsa) at the bedside has been proposed. ⋯ Further studies should be performed to determine the place of Pmsa in the circulatory management of critically ill patients. ( www.clinicaltrials.gov ; TRN NCT04202432, release date 16-12-2019; retrospectively registered). Clinical Trial Registration www. ClinicalTrials.gov , TRN: NCT04202432, initial release date 16-12-2019 (retrospectively registered).
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J Clin Monit Comput · Feb 2022
Ultrasound guided paralaryngeal pressure versus cricoid pressure on the occlusion of esophagus: a crossover study.
The primary objective of this study is to compare the effectiveness of cricoid pressure (CP) and paralaryngeal pressure (PLP) on occlusion of eccentric esophagus in patients under general anesthesia (GA). Secondary objectives include the prevalence of patients with central or eccentric esophagus both before and after GA, and the success rate of CP in occluding centrally located esophagus in patients post GA. Fifty-one ASA physical status I and II patients, undergoing GA for elective surgery were enrolled in this study. ⋯ In 33 patients with eccentric esophagus anatomy post GA, PLP success rate was 30% compared with 27% with CP (P=1.000). Ultrasound guided PLP fingertips technique was not effective in patients with an eccentrically located esophagus post GA. Ultrasound guided CP achieved 100% success rate in patients with a centrally located esophagus post GA.
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J Clin Monit Comput · Feb 2022
Modeling acid-base balance during continuous kidney replacement therapy.
Clinical studies have suggested that use of bicarbonate-containing substitution and dialysis fluids during continuous kidney replacement therapy may result in excessive increases in the carbon dioxide concentration of blood; however, the technical parameters governing such changes are unclear. The current work used a mathematical model of acid-base chemistry of blood to predict its composition within and exiting the extracorporeal circuit during continuous veno-venous hemofiltration (CVVH) and continuous veno-venous hemodiafiltration (CVVHDF). Model predictions showed that a total substitution fluid infusion rate of 2 L/h (33% predilution) with a bicarbonate concentration of 32 mEq/L during CVVH at a blood flow rate of 200 mL/min resulted in only modest increases in plasma bicarbonate concentration by 2.0 mEq/L and partial pressure of dissolved carbon dioxide by 4.4 mmHg in blood exiting the extracorporeal circuit. ⋯ The changes in plasma acid-base levels were larger with a higher infusion rate of substitution fluid but smaller with a higher blood flow rate or use of substitution fluid with a lower bicarbonate concentration (22 mEq/L). Under comparable flow conditions and substitution fluid composition, model predicted changes in acid-base levels during CVVHDF were similar, but smaller, than those during CVVH. The described mathematical model can predict the effect of operating conditions on acid-base balance within and exiting the extracorporeal circuit during continuous kidney replacement therapy.
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J Clin Monit Comput · Feb 2022
Influence of hemorrhage and subsequent fluid resuscitation on transcranial motor-evoked potentials under desflurane anesthesia in a swine model.
Hemorrhage increases the effect of propofol and could contribute to false-positive transcranial motor-evoked potential (TcMEP) responses under total intravenous anesthesia (TIVA). We investigated the influence of hemorrhage and subsequent fluid resuscitation on TcMEPs under desflurane anesthesia. ⋯ TcMEP amplitudes decrease during hemorrhage under desflurane anesthesia. This phenomenon might result from an enhanced effect of desflurane on the spinal motor pathway without increasing the desflurane concentration.