Journal of clinical monitoring and computing
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J Clin Monit Comput · Dec 2024
The time constant of the cerebral arterial bed: exploring age-related implications.
The time constant of the cerebral arterial bed (τ) represents an estimation of the transit time of flow from the point of insonation at the level of the middle cerebral artery to the arteriolar-capillary boundary, during a cardiac cycle. This study assessed differences in τ among healthy volunteers across different age groups. Simultaneous recordings of transcranial Doppler cerebral blood flow velocity (CBFV) and arterial blood pressure (ABP) were performed on two groups: young volunteers (below 30 years of age), and older volunteers (above 40 years of age). τ was estimated using mathematical transformation of ABP and CBFV pulse waveforms. 77 healthy volunteers [52 in the young group, and 25 in the old group] were included. Pulse amplitude of ABP was higher [16.7 (14.6-19.4) mmHg] in older volunteers as compared to younger ones [12.5 (10.9-14.4) mm Hg; p < 0.001]. CBFV was lower in older volunteers [59 (50-66) cm/s] as compared to younger ones [72 (63-78) cm/s p < 0.001]. τ was longer in the younger volunteers [217 (168-237) ms] as compared to the older volunteers [183 (149-211) ms; p = 0.004]. τ significantly decreased with age (rS = - 0.27; p = 0.018). τ is potentially an integrative marker of the changes occurring in cerebral vasculature, as it encompasses the interplay between changes in compliance and resistance that occur with age.
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J Clin Monit Comput · Dec 2024
Multicenter Study Observational StudyCharacterization of intracranial compliance in healthy subjects using a noninvasive method - results from a multicenter prospective observational study.
An FDA-approved non-invasive intracranial pressure (ICP) monitoring system enables the assessment of ICP waveforms by revealing and analyzing their morphological variations and parameters associated with intracranial compliance, such as the P2/P1 ratio and time-to-peak (TTP). The aim of this study is to characterize intracranial compliance in healthy volunteers across different age groups. ⋯ The study revealed that the P2/P1 ratio and TTP are influenced by age and sex in healthy individuals, with men displaying lower values than women, and both ratios increasing with age. These findings suggest potential avenues for further research with larger and more diverse samples to establish reference values for comparison in various health conditions.
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J Clin Monit Comput · Dec 2024
Randomized Controlled Trial Comparative StudyComparing the haemodynamic effects of high- and low-dose opioid anaesthesia: a secondary analysis of a randomised controlled trial.
Post-induction hypotension (MAP < 65 mmHg) occurs frequently and is usually caused by the cardiovascular adverse effects of the anaesthetic induction drugs used. We hypothesize that a clinically significant difference in the incidence and severity of hypotension will be found when different doses of propofol and remifentanil are used for induction of anaesthesia. ⋯ Induction of anaesthesia with different predicted equipotent combinations of propofol and remifentanil did result in statistically different but clinically irrelevant differences in haemodynamic endpoints during induction of anaesthesia. Our study could not identify preferable drug combinations that decrease the risk for hypotension after induction, although they all yield a similar predicted PTOL.
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J Clin Monit Comput · Dec 2024
Associations between intraoperative nociceptive response index and early postoperative acute kidney injury in patients undergoing non-cardiac surgery under general anesthesia: a single-center retrospective cohort study.
Both tissue hypoperfusion and elevated surgical stress during surgery are involved in the pathogenesis of postoperative acute kidney injury (AKI). Although intraoperative hypotension, which evokes renal hypoperfusion, has been reported to be associated with the development of postoperative AKI, there is no consensus on the association between surgical stress responses (e.g., hypertension and inflammation) and postoperative AKI. Given that intraoperative values of nociceptive response (NR) index are reportedly associated with surgical stress responses, the present study was performed to assess associations between intraoperative NR index and postoperative AKI in patients undergoing non-cardiac surgery. ⋯ Data on highest and lowest mean blood pressure (MBP) during surgery were also obtained. In 5,765 patients enrolled, multivariate regression analysis revealed that the development of early postoperative AKI was significantly associated with highest NR during surgery ≥ 0.920, lowest MBP during surgery < 54 mmHg, age ≥ 48 years, male sex, ASA-PS ≥ III, emergency, and duration of surgery ≥ 226 min. In addition to intraoperative hypotension, a higher level of intraoperative NR index is likely associated with higher incidence of early postoperative AKI in adult patients undergoing non-cardiac surgery under general anesthesia.
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J Clin Monit Comput · Dec 2024
Randomized Controlled TrialEffect of continuous measurement and adjustment of endotracheal tube cuff pressure on postoperative sore throat in patients undergoing gynecological laparoscopic surgery: a randomized controlled trial.
Postoperative sore throat (POST) is a common complication following endotracheal tube removal, and effective preventive strategies remain elusive. This trial aimed to determine whether actively regulating intraoperative cuff pressure below the tracheal capillary perfusion pressure threshold could effectively reduce POST incidence in patients undergoing gynecological laparoscopic procedures. ⋯ Continuous monitoring and maintenance of tracheal tube cuff pressure at 18 mmHg were superior to merely monitoring without adjustment, effectively reducing the incidence of POST during quiet within 24 h after tracheal tube removal in gynecological laparoscopic surgery patients.