Journal of Clinical Monitoring and Computing最新文献

Postoperative delirium (POD) is a common and multifactorial complication following cardiac surgery, with cardiopulmonary bypass (CPB) playing a significant contributory role. Impaired cerebral autoregulation (CA) during CPB, particularly in older patients, may lead to cerebral hypo- or hyperperfusion. While several methods exist to assess CA and cerebral blood flow, many require specialized equipment not widely available. This prospective observational study aimed to investigate whether altered cerebral artery flow velocity, measured preoperatively by transcranial Doppler (TCD), is associated with the development of POD. We enrolled 41 patients undergoing elective cardiac surgery with CPB. Bilateral peak flow velocities of the middle cerebral arteries were measured preoperatively using TCD. The mean middle cerebral artery velocity (mMCAv_mean) was calculated for each patient. POD occurred in 21 patients (51%). A lower mMCAv_mean was significantly associated with an increased risk of POD. Specifically, each 1 cm/s decrease in mMCAv_mean increased the likelihood of POD by 9.2% (odds ratio 0.908; 95% confidence interval: 0.840-0.981; p = 0.015). Reduced cerebral blood flow velocity during CPB, as measured by TCD, is associated with a higher risk of POD. These findings highlight the potential utility of intraoperative TCD monitoring for early identification of at-risk patients and support further research into TCD-guided preventive strategies in cardiac surgery.

Clinical ultrasound in the hands of physicians is rich with experiences from various medical specialties. As point of care ultrasound has revolutionized patient care in the perioperative period, it is important to reflect on the beginnings, and the path taken to modern day portable devices. As anesthesiologists, point of care ultrasound has become embedded into all aspects of perioperative care to improve patient outcomes. Advancements in technology continue to extend the boundaries for use by anesthesiologists and redefine the standard of care in the perioperative period. This article reflects on the path of point-of-care ultrasound from its beginning to the present day and discusses future directions. A summary of key findings is shown.

To evaluate the effects of three simple bedside challenges on cerebral oxygenation and brain activity, measured non-invasively using near-infrared spectroscopy (NIRS) and frontal single-channel electroencephalography (EEG), in comatose post-cardiac arrest patients, and to examine whether these responses differ according to cerebral autoregulation status and intensive care unit (ICU) outcome and could aid early prognostication. Three bedside physiological challenges were conducted: (1) increasing the fraction of inspired oxygen (FiO₂) to 100%, (2) lowering the head-of-bed (HOB) to 0°, and (3) elevating end-tidal carbon dioxide (etCO₂) by 1.0 kPa. Tissue oxygen saturation (StO₂) and EEG amplitude were hypothesized to increase, by enhancing oxygen delivery (FiO₂), augmenting cerebral perfusion pressure (HOB), and inducing cerebral vasodilation (etCO₂). Furthermore, we examined the associations between signal responses, cerebral autoregulation status, and ICU outcome. Of the 48 monitored patients, FiO₂, HOB, and etCO₂ challenges were successfully completed in 41 (85%), 33 (69%), and 32 (67%) patients, respectively. The StO₂ increased on average by 0.3% (95%-CI 0.2-0.5, p < 0.001) for every 10% rise in FiO₂, and 1.94% (95%-CI 0.9-3.0, p < 0.001) for each 15º lowering of the HOB. The etCO₂ challenge did not affect the StO₂. EEG amplitude remained unchanged during all three challenges. No significant differences were found in the responses between patients with intact versus impaired autoregulation or between the ICU outcome groups. Brief physiological challenges simulating common ICU scenarios elicited only modest increases in StO₂, and no measurable response in EEG amplitude. Response patterns were not associated with cerebral autoregulation status or ICU outcome.

Depth-of-anesthesia monitoring, particularly in functional neurosurgical procedures such as asleep deep brain stimulation, is critical for balancing individualized neurophysiological needs with perioperative safety. Parkinson's disease (PD) patients with rapid-eye-movement sleep behavior disorder (RBD) demonstrate wakefulness electroencephalographic (EEG) abnormalities that may confound monitoring. Whether these RBD-associated EEG patterns persist under propofol anesthesia and distort monitoring indices remains to be elucidated. This study therefore aimed to determine if propofol anesthesia in PD-RBD patients disrupts coherence between anesthesia depth indices and true neurophysiological states. We retrospectively analyzed SedLine^®-monitored prefrontal EEG data from 43 PD patients undergoing subthalamic nucleus deep brain stimulation, divided into non-RBD (n = 23) and RBD (n = 20) groups. Evaluations were conducted across awake, propofol anesthesia, and propofol light anesthesia states during microelectrode recording, including power spectral density analysis, derived parameter comparisons, and postoperative outcomes. Results showed RBD patients had lower patient state index values during wakefulness (p = 0.034) but displayed comparable patient state index, spectral edge frequency, and suppression ratio under anesthesia; notably stronger gamma suppression occurred in RBD patients during propofol anesthesia (p = 0.027) and light anesthesia states (p = 0.011), along with higher postoperative delirium incidence (65.00%). Logistic regression identified associations between postoperative delirium risk and RBD status, Mini-Mental State Examination scores, and propofol-induced theta power, with theta power emerging as a protective factor. Collectively, PD-RBD patients exhibit abnormal EEG under propofol anesthesia but maintain reliable depth-of-anesthesia indices, necessitating customized anesthesia care and delirium prevention. Clinical Trial Number: ChiCTR2400082770, 2024-04-07, ClinicalTrials.gov).

The Mean flow index (Mxa) is widely used to assess dynamic cerebral autoregulation in different clinical populations. This calculation is based on defined characteristics, including blocks, overlap periods, and epochs of the whole recordings. This study aimed to investigate the reproducibility of different Mxa calculations, using variable blocks, overlap periods, and epochs. We retrospectively analyzed 50 transcranial Doppler recordings from septic shock patients, acquired within 48 h of ICU admission. Mxa was computed using eight signal-processing strategies that varied by block duration (5-10 s), overlap percentage (20%, 50%, 80%), and epoch length (3-5 min), as well as a continuous approach without epochs. Each configuration was labeled using the format epoch-block-overlap. Mxa values were compared using repeated measures analyses, intraclass correlation coefficients (ICC), Bland-Altman plots, and polychoric correlation heatmaps. Median Mxa values ranged from 0.36 to 0.45 across configurations, with no statistically significant differences in within-patient comparisons (p > 0.05). ICCs demonstrated excellent agreement (ICC > 0.90) between approaches using the same epoch duration. Agreement declined modestly when comparing configurations with different epoch lengths (e.g., ICC = 0.782 between 3-10-50 and 5-10-50). Fixed-effects analysis did not identify any individual segmentation parameter as a significant source of variability. Mxa values calculated using different combinations of block, overlap, and epoch duration were consistent within patients, particularly when epoch length was maintained. These findings support the reproducibility of Mxa and suggest flexibility in processing strategies, provided methodological consistency is maintained. Further validation is warranted.

This study aimed to evaluate whether continuous axillary temperature monitoring using a wearable patch enables earlier detection of postoperative infections compared to conventional intermittent infrared thermometry. 103 surgical patients were included in this prospective, single-center study and monitored over an 11-month period. Continuous axillary temperature monitoring using the SteadyTemp^® patch was compared to routine infrared measurements performed as part of clinical routine. The primary outcome was fever detection rate (≥ 38.0 °C). Secondary outcomes included the correlation between fever detection and laboratory values as well as the frequency of clinical interventions. Out of 103 included patients, fever was detected in 33 cases. Continuous monitoring identified fever in 31 of these 33 patients (93.9%), whereas infrared thermometry detected fever in only 12 cases (36.4%). In 16 cases where antibiotic therapy was initiated or adjusted due to newly detected fever, the patch detected fever in 15 patients, compared to only 7 detections by infrared thermometry. Surgical interventions due to suspected infections were performed in 5 patients, and fever was detected by the patch in all cases, while infrared thermometry detected fever in only 2 of these patients. Due to the frequent failure of infrared thermometry to detect fever, a scoring system was developed to assess the clinical relevance of fever detection. Continuous temperature monitoring with the SteadyTemp^® patch demonstrated superior fever detection compared to infrared thermometry, leading to earlier identification of febrile events. This study suggests that continuous temperature monitoring may enhance infection surveillance in surgical patients, allowing for more timely clinical interventions.

Ultrasound Elastography (UE) tends to improve the ultrasound diagnosis accuracy. The Strain Elastography (SE) depicts the pathological tissue loss of elasticity in response to an external pressure applied by the operator. It is now recommended for benign/malignant parenchymal process differentiation and for muscle and nervous rigidness assessment and follow-up. The SE was able to differentiate the normal nerves from their muscular-vascular environment based on their own elasticity using a colorimetric scale (CS)0.30 healthy adult patients were included into this prospective observational study. The femoral nerve (FN) and the popliteal sciatic nerve (PSN) were studied using 2D black and white sonography (S) and SE. About the SE, firstly, CS goes from red (stiffer) to blue (softer) differentiating 6 main colors at the visual assessment. Secondly, the CS was transformed into a 3 points tissues classification related to FN and PSN elasticity for easier reading. Results are presented as percentages.FN and PSN in sonography were normal in all patients confirming the different morphology of each kind of nerve with a high level of patient-to-patient reproducibility. SE detected as "stiff" the FN and PSN in respectively 87 and 83% of the patients. Finally, a superposition between sonogram and elastogram greater than 50% was observed in 54 and 70% of the patients.SE represents a promising technique that may complement S to try to improve the quality of nerve localization. Further and larger studies are needed for a better understanding the subject in real clinical conditions.

We evaluated the accuracy and precision of zero-heat flux (ZHF) and dual sensor (DS) non-invasive temperature probes in intensive care unit (ICU) patients undergoing hypothermic temperature control, hypothesizing that both devices would accurately estimate core temperature. In a single-center prospective cohort study, we enrolled 35 ICU patients and applied continuous, non-invasive ZHF and/or DS probes to the lateral forehead or anterior chest to collect 358 observations. Conditions potentially influencing temperature estimation were recorded. Using Bland-Altman analysis with multiple paired observations per individual, we compared the bias between non-invasive probes and direct core temperature measurements. Lin's concordance coefficient (LCC) was computed to quantify precision. The mean bias between the ZHF probe and invasive temperature was + 0.98 °C; for the DS probe, it was - 2.19 °C. In hypothermic patients, the ZHF probe's accuracy improved (bias + 0.28 °C, LCC 0.86), while the DS probe remained inaccurate (bias - 2.52 °C, LCC 0.07). Clinical confounders like vasoactive agents or temperature control devices did not consistently affect bias, accuracy, or precision. Neither the ZHF nor DS non-invasive probes provided sufficient accuracy or precision to guide clinical decisions in the ICU. These results contrast with previous studies reporting biases within ± 0.5 °C. However, the ZHF probe showed promising limited deviation, especially in hypothermic patients.