Journal of clinical monitoring and computing
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J Clin Monit Comput · Apr 2022
Observational StudyMechanisms contributing to hypotension after anesthetic induction with sufentanil, propofol, and rocuronium: a prospective observational study.
It remains unclear whether reduced myocardial contractility, venous dilation with decreased venous return, or arterial dilation with reduced systemic vascular resistance contribute most to hypotension after induction of general anesthesia. We sought to assess the relative contribution of various hemodynamic mechanisms to hypotension after induction of general anesthesia with sufentanil, propofol, and rocuronium. In this prospective observational study, we continuously recorded hemodynamic variables during anesthetic induction using a finger-cuff method in 92 non-cardiac surgery patients. ⋯ Anesthetic induction with sufentanil, propofol, and rocuronium reduced arterial pressure and systemic vascular resistance index. Heart rate, stroke volume index, and cardiac index remained stable. Post-induction hypotension therefore appears to result from arterial dilation with reduced systemic vascular resistance rather than venous dilation or reduced myocardial contractility.
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J Clin Monit Comput · Apr 2022
Randomized Controlled TrialEffects of Varying Levels of Inspiratory Assistance with Pressure Support Ventilation and Neurally Adjusted Ventilatory Assist on Driving Pressure in Patients Recovering from Hypoxemic Respiratory Failure.
Driving pressure can be readily measured during assisted modes of ventilation such as pressure support ventilation (PSV) and neurally adjusted ventilatory assist (NAVA). The present prospective randomized crossover study aimed to assess the changes in driving pressure in response to variations in the level of assistance delivered by PSV vs NAVA. ⋯ NAVA delivers better lung-protective ventilation compared to PSV in hypoxemic ARF patients.
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J Clin Monit Comput · Apr 2022
Needle insertion forces and fluid injection pressures during targeting of nerves in a soft embalmed cadaver model.
Forceful needle-nerve contact and high subepineural pressures and are recognised causes of nerve damage. Pressure and force measurements are necessary to inform the mechanisms of nerve injury, build virtual simulator environments and provide operator feedback during simulation training. However, the range of pressures and forces encountered at tissue layers during targeted needle insertion and fluid injection are not known. ⋯ Pressure was greater at epineurium and within subepineurium than perineural tissue, geometric ratio (95% CI) 4.7 (3.0-7.3) kPa and 3.8 (2.5-5.7) kPa, respectively, both P < 0.0001. Force on nerve contact and on nerve penetration was greater than force in perineural tissue, geometric ratios (95% CI) 3.0 (1.9-4.7) N and 3.6 (2.2-7.5) N, respectively, both P < 0.0001. On nerve contact, 1 in 6 insertions were ≥ 5 N CONCLUSIONS: Despite valid infusion pressures, anaesthetists exerted excessive force on nerves.
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J Clin Monit Comput · Apr 2022
ReviewEstimation of cardiac output variations induced by hemodynamic interventions using multi-beat analysis of arterial waveform: a comparative off-line study with transesophageal Doppler method during non-cardiac surgery.
Multi-beat analysis (MBA) of the radial arterial pressure (AP) waveform is a new method that may improve cardiac output (CO) estimation via modelling of the confounding arterial wave reflection. We evaluated the precision and accuracy using the trending ability of the MBA method to estimate absolute CO and variations (ΔCO) during hemodynamic challenges. We reviewed the hemodynamic challenges (fluid challenge or vasopressors) performed when intra-operative hypotension occurred during non-cardiac surgery. ⋯ After hemodynamic challenge, the percentage of concordance (PC) with 15% exclusion zone for ΔCO was 93 (CI97.5 = 90 to 97)%. In this retrospective offline analysis, the accuracy, limits of agreements and percentage error between TED and MBA for the absolute estimation of CO were poor, but the MBA could adequately track induced CO variations measured by TED. The MBA needs further evaluation in prospective studies to confirm those results in clinical practice conditions.
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J Clin Monit Comput · Apr 2022
Randomized Controlled TrialTo compare clinical versus ultrasound assessment of correct placement of ProSeal Laryngeal mask airway (PLMA): a prospective randomized study.
Extraglottic airway devices (EAD) have revolutionized the perioperative airway management. The accuracy of clinical tests to identify malposition has been questioned by recent studies where fibreoptic evaluation identified various malpositions that were undiagnosed by a clinical test. Ultrasound (USG) has evolved to guide various airway interventions. ⋯ USG is comparable to clinical tests for evaluation of the optimal placement of PLMA. However, USG has various advantages over clinical assessment as it is quick and identifies the unacceptable placement of PLMA where the tip of PLMA may not lie over the tip of the esophagus, thereby, avoiding unnecessary mucosal injury during forceful or repeated attempts for gastric drainage tube insertion. Trial registration: Clinical Trials Registry (CTRI/2017/11/010359) dated 3rd November 2017.