Journal of clinical monitoring and computing
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J Clin Monit Comput · Dec 2020
Observational StudyPerioperative measurement of core body temperature using an unobtrusive passive heat flow sensor.
Clinicians strive to maintain normothermia, which requires measurement of core-body temperature and may necessitate active warming of patients. Monitoring temperature currently requires invasive probes. This work investigates a novel foam-based flexible sensor worn behind the ear for the measurement of core body temperature. ⋯ The error bias and limits of agreement over these segments were on average of - 0.05 ± 0.28 °C (95% limits of agreement) overall. The dynamic model outperformed the simple heat-flow model for periods of surrounding temperature changes (12.7% of total time) while it had a similar, high, performance for the temperature-stable periods. The results suggest that our proposed topical sensor can replace invasive core temp sensors and provide a means of consistently measuring core body temperature despite surrounding temperature shifts.
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J Clin Monit Comput · Dec 2020
The Peripheral Perfusion Index tracks systemic haemodynamics during general anaesthesia.
Stable intraoperative haemodynamics are associated with improved outcome and even short periods of instability are associated with an increased risk of complications. During anaesthesia intermittent non-invasive blood pressure and heart rate remains the cornerstone of haemodynamic monitoring. Continuous monitoring of systemic blood pressure or even -flow requires invasive or advanced modalities creating a barrier for obtaining important real-time haemodynamic insight. ⋯ After stabilizing a second HUT decreased PPI 59% (49-76), SV 33% (28-37), CO 31% (28-36), and MAP 34% (26-38). Restoration of preload with PE increased PPI by 607% (218-1078), SV by 96% (82-116), CO by 65% (56-99), and MAP by 114% (83-147). During general anaesthesia changes in PPI tracked changes in systemic haemodynamics.
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J Clin Monit Comput · Dec 2020
Randomized Controlled TrialShortening of the twitch stabilization period by tetanic stimulation in acceleromyography in infants, children and young adults (STSTS-Study): a prospective randomised, controlled trial.
Acceleromyography is characterised by an increase of the twitch response T1 (first twitch of the train-of-four [TOF]) during first 30 min of monitoring known as the staircase phenomenon. In adults the staircase phenomenon can be avoided by tetanic prestimulation. This study examined, if tetanic prestimulation eliminates the staircase phenomenon in children. ⋯ Tetanic prestimulation prevents the staircase phenomenon in these age groups. The stability of the TOFR reading confirms its value to monitor neuromuscular function over time. Registration: The study was registered as NCT02552875 on Clinical Trials.gov on July 29, 2014.
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J Clin Monit Comput · Dec 2020
Do changes in perfusion index reflect changes in stroke volume during preload-modifying manoeuvres?
Changes in stroke volume (deltaSV) induced by a lung recruitment manoeuvre (LRM) have been shown to accurately predict fluid responsiveness during protective mechanical ventilation. Cardiac output monitors are used in a limited number of surgical patients. In contrast, all patients are monitored with a pulse oximeter, that may enable the continuous monitoring of a peripheral perfusion index (PI). ⋯ A deltaPI ≥ 26% predicted a deltaSV > 30% with a sensitivity of 83% and a specificity of 78% (AUC = 0.84, 95%CI 0.71-0.93). 24 patients experienced a deltaSV > 30% and subsequently received fluid. Fluid loads induced a 16% increase in SV and a 17% increase in PI, but fluid-induced deltaPI and deltaSV were weakly correlated (r2 = 0.19). In neurosurgical patients, we conclude that deltaPI may be used as a surrogate for deltaSV during LRMs but not during fluid loading.
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J Clin Monit Comput · Dec 2020
Observational StudySurrogate indices of aortic peak systolic velocity variation to monitor fluid responsiveness in pediatric non-cardiac surgery: a prospective observational study.
Aortic peak systolic velocity variation (ΔVpeakAo) is a reliable dynamic indicator of preload in mechanically ventilated children. However, easily measurable alternative parameters like carotid peak systolic velocity variation (ΔVpeakCa) and suprasternal peak systolic velocity variation (ΔVpeakSs) are not well evaluated in children. The aim of the study was to find correlation between ΔVpeakCa and ΔVpeakSs to ΔVpeakAo, as potential surrogate markers of fluid responsiveness. 52 children, 1-12 years old, undergoing major non-cardiac surgeries under general endotracheal anaesthesia were recruited for this single-centre prospective observational study. ΔVpeakAo, ΔVpeakCa and ΔVpeakSs were measured by pulsed wave Doppler in appropriate windows, measuring maximum and minimum peak flow velocity over a single respiratory cycle. ⋯ Bland-Altman analysis showed minimal bias of 1.86 percentage points with limits of agreement of 11.21 to - 7.49 (ΔVpeakAo and ΔVpeakSs) and 3.93 percentage points with limits of agreement of 14.04 to - 6.18 (ΔVpeakAo and ΔVpeakCa). ΔVpeakSs and ΔVpeakCa also showed good discrimination to predict ΔVpeakAo (lying in previously validated fluid responsive zones) with sensitivities and specificities of 82.25% and 85% with cut-off of 11% for ΔVpeakSs, and 88.52% and 70% with cut-off of 8.6% for ΔVpeakCa. Carotid peak systolic velocity variation (ΔVpeakCa) and suprasternal peak systolic velocity variation (ΔVpeakCa) can be potential surrogate markers for Aortic peak systolic velocity variation (ΔVpeakAo) in assessing fluid responsiveness in mechanically ventilated children. Study registration: Clinicaltrials.gov ID NCT03155555.