Journal of clinical monitoring and computing
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J Clin Monit Comput · Dec 2023
Cardiac surgery-associated acute kidney injury and perioperative plasma viscosity: is there a relationship?
Plasma viscosity (PV) is a key factor in microcirculatory flow resistance and capillary perfusion during hemodilution, we hypothesized a possible relationship between cardiac surgery-associated acute kidney injury (CSA-AKI) and PV. We conducted a prospective, observational, single-center study on 50 adult cardiac surgery patients with cardiopulmonary bypass (age 64 years, male sex 80%, baseline serum creatinine 1.04 mg/dL). We assessed perioperative characteristics, management, short-term outcomes, blood analysis, PV, serum creatinine, and diuresis. ⋯ However, CSA-AKI was related to increased BMI, lower hemoglobin and hematocrit levels, and pre-existing CKD. The present study found no significant association between PV and CSA-AKI. Nevertheless, more research is needed to validate this finding and to investigate the role of PV in other clinical settings.
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J Clin Monit Comput · Dec 2023
Observational StudyEffectiveness of substantial shortening of the endotracheal tube for decreasing airway resistance and increasing tidal volume during pressure-controlled ventilation in pediatric patients: a prospective observational study.
The endotracheal tubes (ETTs) used for children have a smaller inner diameter. Accordingly, the resistance across ETT (RETT) is higher. Theoretically, shortening the ETTs can decrease total airway resistance (Rtotal), because Rtotal is sum of RETT and patient's airway resistance. ⋯ The laboratory experiment showed that ETT length and the pressure gradient across ETT are linearly related under a certain flow rate, and approximately 40% of the pressure gradient across the ETT at its original length was generated by the slip joint. Median RETT/Rtotal ratio were calculated as 0.69. The effectiveness of ETT shortening on Rtotal and TV was very limited, because the resistance of the slip joint was very large.
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J Clin Monit Comput · Dec 2023
Editorial CommentPerioperative monitoring of the oxygen reserve: where do we stand?
The Oxygen Reserve Index (ORi) is an advanced plethysmography-derived variable that may help to quantify the degree of hyperoxia in patients receiving supplemental oxygen administration. ORi is a (relative) indicator of the actual partial pressure of oxygen dissolved in arterial blood (PaO2). ⋯ Within the moderate hyperoxic range (100-200 mmHg PaO2), there is a sound correlation between ORi and PaO2. This editorial discusses the clinical implications of this validation study and elaborates on the possible role of ORi monitoring in addition to SpO2 (peripheral arterial oxygen saturation) monitoring alone.
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J Clin Monit Comput · Dec 2023
"The peripheral perfusion index discriminates haemodynamic responses to induction of general anaesthesia".
Induction of general anaesthesia is often accompanied by hypotension. Standard haemodynamic monitoring during anaesthesia relies on intermittent blood pressure and heart rate. Continuous monitoring systemic blood pressure requires invasive or advanced modalities creating a barrier for obtaining important information of the circulation. ⋯ In the 69 patients where PPI increased the corresponding values were MAP 70(± 15)%, SV 80(± 16)%, and CO 68(± 17)% (all differences: p < 0,001). During induction of general anaesthesia changes in PPI discriminated between the degrees of reduction in blood pressure and algorithm derived cardiac stroke volume and -output. As such, the PPI has potential to be a simple and non-invasive indicator of the degree of post-induction haemodynamic changes.
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J Clin Monit Comput · Dec 2023
Arterial blood pressure waveform in liver transplant surgery possesses variability of morphology reflecting recipients' acuity and predicting short term outcomes.
We investigated clinical information underneath the beat-to-beat fluctuation of the arterial blood pressure (ABP) waveform morphology. We proposed the Dynamical Diffusion Map algorithm (DDMap) to quantify the variability of morphology. The underlying physiology could be the compensatory mechanisms involving complex interactions between various physiological mechanisms to regulate the cardiovascular system. As a liver transplant surgery contains distinct periods, we investigated its clinical behavior in different surgical steps. ⋯ The neohepatic phase variability of morphology was associated with EAF scores as well as postoperative bilirubin levels, international normalized ratio, aspartate aminotransferase levels, and platelet count. Furthermore, variability of morphology presents more associations with the above clinical conditions than the common BP measures and their BP variability indices. The variability of morphology obtained during the presurgical phase is indicative of patient acuity, whereas those during the neohepatic phase are indicative of short-term surgical outcomes.