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Hemodynamic optimization is key to resuscitation of critically ill patients in intensive medicine. Delayed or improper treatment will inevitably lead to hypoperfusion, tissue hypoxia and multiple organ failure, which affects the patients' outcome. Therefore, early identification of patients at risk and implementation of adequate monitoring and guidance intervention have a profound impact on the results. The key principle of hemodynamic management is to optimize blood flow and oxygen flow according to current tissue metabolism. To achieve this goal, we need to monitor and get blood pressure, cardiac output, organ-specific automatic regulation and tissue microcirculation. However, the clinical monitoring data is huge. At the same time nearly one hundred pieces of data objectively present the pathophysiological state of the patient, and the changes of data at different time periods can describe the progress of the patients' condition. Therefore, the integrated analysis of time/ frequency domain based on millisecond-level high-resolution data will promote the understanding and practice of hemodynamics at microcosmic level, and help to facilitate clearer judgment and more precise treatment of patients' condition.

Neurocritical care is an important branch of critical care medicine. The mechanism of critical neurological damage is complex and diverse, and the pathophysiology changes rapidly. Different pathophysiological changes determine different degrees of brain injury. In a special plateau environment, the incidence of critical neurological disease is higher, the age of onset is younger, the disease progress is faster, and the degree of damage is more severe. In order to standardize the diagnosis and treatment, enhance monitoring and management, provide timely and precise treatment, prevent irreversible brain injury, and improve the prognosis of patients with critical neurological illness at high altitudes, the Research Group of Calm Treatment of China, Research Group of Critical Care Ultrasound of China, and the Quality Control Center of Critical Care Medicine in Tibet formulated the Expert Consensus on Monitoring and Management of Patients with Critical Neurological Illness at High Altitudes on the basis of full discussion and communication of relevant critical medical experts and neurosurgery experts according to domestic and foreign literature and years of experience in clinical application and promotion. The main contents of the consensus are as follows.(1) According to the pathophysiological mechanism of neurological involvement in critical illness, scenarios of neurocritical care at high altitudes can be divided into cerebral hemorrhage at high altitudes, severe traumatic brain injuries, ischemic stroke, cerebral edema at high altitudes, and septic encephalopathy (8.4 points).(2) It is recommended to use cerebral blood flow, brain function monitoring and cerebral oxygen saturation as a 'triad' monitoring core in management of neurocritical care at high altitude, to as well as cerebrospinal fluid dynamics monitoring and brain structure surveillance (9.0 points).(3) It is recommended to grade patients quickly, and the '5-avoids' approach based on 'brain protection' theory were adhered to avoid fever, seizures, anxiety, agitation or pain, shivering, stimulation and nociception, according to different levels. Especially in the 'super critical' stage, with the protection of '446'targets, choose the window for analgesia and sedation (8.4 points).(4) It is recommended to monitor systemic and cerebral hemodynamic continuously and dynamically in order to improve systemic perfusion and optimize cerebral perfusion simultaneously (8.4 points).(5) It is recommended to choose the method of direct measurement of intracranial pressure by intraventricular catheter or optic nerve sheath diameter under ultrasound to estimate intracranial pressure, and choose the appropriate target mean arterial pressure to ensure optimal brain perfusion (8.8 points).(6) It is recommended to use transcranial Doppler ultrasound to evaluate the blood flow velocity and blood flow waveform of the bilateral cerebral arteries. It is recommended to target the blood flow velocity of M1 at 40 cm/s in the 'super critical' period (8.2 points).(7) In the 'super critical' period, we recommend to routinely monitor BIS and maintain the BIS value around 40 as the goal to guide the depth of sedation; those with conditions can be monitored by quantitative electroencephalography to assist determining whether there are non-convulsive seizures, and perform diagnostic evaluation of the prognosis (8.6 points).(8) It is recommended to monitor brain oxygen levels routinely, starting early in the ICU admission of patients with critical neurological conditions at high altitudes, which can assist in the assessment of brain damage (8.6 points).(9) It is recommended to evaluate the cerebral blood flow self-regulation ability routinely to achieve the optimal cerebral perfusion pressure in time and timely adjust the intensity and scheme of treatment (8.2 points).(10) It is recommended to emphasize the importance of target arterial partial pressure of carbon dioxide in the artery in critical illness and neurocritical care at high altitudes (8.0 points).(11) It is recommended to devote attention to the importance of targeted temperature management in in critical illness and neurocritical care at high altitudes (8.6 points).(12) It is recommended that multidisciplinary consultation and multi-professional cooperation could improve the management in critical neurological illness at high altitudes (8.8 points).(13) It is recommended that the constitution of improvement in brain structure imaging, pressure normalization of cerebrospinal fluid and restoration of cerebral blood autoregulation could be as the de-escalation triad (8.0 points).(14) It is recommended to be cautious of paroxysmal sympathetic hyperreactivity patients in neurocritical and critical illness at high altitude (8.0 points).(15) It is recommended to be cautious about the management of agitation (delirium) and cognitive function of patients in TBI at high altitudes(8.0 points).(16) It is recommended to assess the itinerary of the rehabilitation in a timely manner for critically sick patients at high altitudes (8.2 points).(17) It is recommended to be cautious of post-traumatic hydrocephalus and related neuroendocrine abnormalities in patients with critical neurological illness at high altitudes (7.6 points).

Objective: This study explores alterations in renal cortical perfusion post-Early Goal-Directed Therapy (EGDT) in sepsis patients, to investigate its association with major adverse kidney events within 30 days (MAKE-30) and identify hemodynamic factors associated with renal cortical perfusion., Methods: Sepsis patients admitted to the ICU from Jan 2022 to Jul 2023 were prospectively enrolled. Contrast-enhanced ultrasound (CEUS) assessed renal cortical perfusion post-EGDT. Hemodynamic parameters and renal resistive index (RRI) were collected. Patients were categorized into MAKE-30 and non-MAKE-30 groups. The study examined the association between renal cortical perfusion and MAKE-30, explored the hemodynamic factors related to renal cortical perfusion., Results: Of 94 sepsis patients, 46 (48.9 %) experienced MAKE-30. Distinctions in pulmonary (P = 0.012) and abdominal infection sites (P = 0.001) and significant SOFA (P < 0.001) and APACHE II scores (P = 0.003) differences were observed. No significant differences in baseline characteristics, vasopressor, or diuretic doses were noted (P > 0.05). Hemodynamic parameters in MAKE-30 and non-MAKE-30 patients showed no significant differences. RRI was higher in MAKE-30 patients (0.71 vs 0.66 P = 0.005). Renal microcirculation parameters, including AUC (p = 0.035), rBV (p = 0.021), and PI (p = 0.003), were lower in MAKE-30. Reduced cortical renal perfusion was associated with an increased risk of MAKE-30. Renal cortical perfusion RT was identified as an independent factor associated with this risk (HR 2.278, 95 % CI (1.152-4.507), P = 0.018). RRI correlated with renal cortical perfusion AUC (r = -0.220 p 0.033)., Conclusion: Despite normal systemic hemodynamics post-sepsis EGDT, MAKE-30 patients show reduced renal cortical perfusion. CEUS-derived RT is an independent factor associated with this change. RRI correlates with renal cortical perfusion., Competing Interests: Declaration of competing interest The datasets reported in this study were provided by the Fourth Hospital of Hebei Medical University. The interpretation and reporting of these data are the responsibility of the authors, and should not be regarded as an official policy or interpretation of the Fourth Hospital of Hebei Medical University., (Copyright © 2024. Published by Elsevier Inc.)

Background: The effectiveness of critical care ultrasound has been demonstrated and training for it is urgent. Critical Care Ultrasound Study Group (CCUSG) has been dedicated to ultrasound training. The aim of the study was to evaluate course structure and training effect and provide improvement suggestions for future training., Methods: A multicenter retrospective study was conducted. All participants went through a 2-day training curriculum based on the critical care ultrasonic examination (CCUE) protocol. Pre- and post-class evaluation were applied and data were collected. Non-parametric tests were adopted for the comparison, and a Generalized Linear Model (GLM) was used for further analysis., Results: A total number of 792 trainees, with a mean age of 35.8, participated in the study. There were more males in the study population. Most of the trainees were attendings, and most of them had bachelor's degrees, worked at tertiary hospitals and had a mean working experience of 6.9 years. The scores of all trainees were improved to various degrees after the course. An increase from 50% to 72% (P≤0.001) was seen in theory test scores. All the competency assessment scores, including IAS (34% to 50% for cardiac images and 30% to 60% for pulmonary images), IPS (30% to 50%) and AAS (31% to 44%), were improved. A questionnaire after class suggested that 88.0% of the participants found the training course very useful., Conclusion: 2-day training course can improve the ability of physicians to assess critically ill patients with the help of the ultrasound., Competing Interests: None., (AJTR Copyright © 2024.)

The multiple etiological characteristics of acute kidney injury (AKI) have brought great challenges to its clinical diagnosis and treatment. Renal injury in critically ill patients always indicates hemodynamic injury. The Critical Care UltraSound Guided (CCUSG)-A (KI) BCDE protocol developed by the Chinese Critical Ultrasound Study Group (CCUSG), respectively, includes A (KI) diagnosis and risk assessment and uses B-mode ultrasound, Color doppler ultrasound, spectral Doppler ultrasound, and contrast Enhanced ultrasound to obtain the hemodynamic characteristics of the kidney so that the pathophysiological mechanism of the occurrence and progression of AKI can be captured and the prognosis of AKI can be predicted combined with other clinical information; therefore, the corresponding intervention and treatment strategies can be formulated to achieve targeted, protocolized, and individualized therapy.

Objective: To investigate the differences of the locations and signs of the phrenic points between the Modified Bedside Lung Ultrasound Examination (M-BLUE) and Bedside Lung Ultrasound Examination (BLUE)., Methods: A total of 61 consecutive patients who were treated in the Department of Critical Care Medicine at Peking Union Medical College Hospital in January and February of 2015 were enrolled in this study. BLUE and M-BLUE were both performed on each patient. The differences of examination results were compared., Results: (1) There were 47.5% (58/122) different locations of the phrenic points and 18.0% (22/122) different echo-signs between the BLUE protocol and the M-BLUE protocol. (2) Compared with BLUE protocol, changes of locations [67.9% (19/28) vs 33.3% (11/33)] and signs [42.9% (12/28) vs 12.1% (4/33)] of the phrenic points in the M-BLUE protocol in patients with respiratory failure were significantly higher than those without pulmonary diseases. Among 5 patients with acute respiratory distress syndrome and 6 patients with chronic obstructive pulmonary disease, all presented changes in locations of the phrenic point in the M-BLUE protocol, while 3 and 4 showed changes in signs respectively. (3) Signs of the phrenic point in the M-BLUE protocol were more consistent with the result of the chest CT than those in the BLUE protocol., Conclusion: Compared with BLUE protocol, M-BLUE protocol seems more accurate in locating the phrenic point and more specific for the diagnosis of pulmonary disease. Compared with BLUE protocol, M-BLUE is more valuable for critical patients.

The aim of the present study was to explore a novel insight to determine the positive end expiratory pressure (PEEP) for sustained ventilation after lung recruitment in an acute respiratory distress syndrome (ARDS) model. Continuous infusion of oleic acid was performed to establish a ARDS model. Pressure control ventilation (PCV) was applied for lung recruitment with PEEP of 20 cm H2O. After lung recruitment, maneuver was changed to volume-controlled ventilation and PEEP titration were performed by decreasing PEEP gradually starting from the level of 20 cm H2O. The optimal level of PEEP for sustained ventilation was set as the lowest PEEP until oxygen partial pressure (PaO2) plus carbon dioxide partial pressure (PaCO2) ≥400 mmHg. Hemodynamic and respiratory parameters at basal level, ARDS state and different levels of PEEP around the optimal PEEP were recorded. The defined optimal PEEP was 13.14 ± 1.35 cm H2O. Respiratory parameters including intrapulmonary shunt (Qs/Qt) and arterial oxygen saturation (SaO2) were significantly improved by various levels of PEEP for sustained ventilation after lung recruitment (P<0.05). Static compliance (Cst) and dynamic compliance (Cdyn) were also significantly increased after application of different levels of PEEP ventilation after lung recruitment (P<0.05). There was no significant statistic difference on most hemodynamic parameters (P>0.05) between various levels of PEEP. The application of different PEEP levels around the defined optimal PEEP had an obvious improvement on respiratory mechanics and gas exchange for collapsed lung tissue without influencing the hemodynamics.

Objective: To evaluate the value of lung ultrasound score (LUS) on assessing the severity and prognosis in patients with acute respiratory distress syndrome (ARDS), and to investigate its correlation with oxygenation index, acute physiology and chronic health evaluationII (APACHEII) score, sequential organ failure assessment (SOFA) score, and clinical pulmonary infection score (CPIS), and other traditional parameters., Methods: A prospective double-blind cohort study was conducted. Sixty-two ARDS patients conformed to the Berlin diagnostic criteria admitted to intensive care unit (ICU) of Beijing Huaxin Hospital from October 2013 to December 2014 were enrolled, including 14 cases with mild, 18 moderate, and 30 severe ARDS; among them 37 cases were of ARDS with pulmonary origin, and 25 non-pulmonary ARDS; 35 patients survived, and 27 died. The clinical data and scores of all patients were recorded by one specialized observer, including baseline data, hemodynamic parameters, lactate, respiratory parameters, and APACHEII, SOFA and CPIS scores. Another observer of recording was responsible for the results of lung ultrasound, LUS, and echocardiogram. The correlation between LUS and oxygenation index as well as APACHEII, SOFA and CPIS scores was analyzed by bivariate correlation analysis. Receiver operator characteristic curve (ROC) was plotted, and the predictive value, sensitivity and specificity of mild ARDS, moderate ARDS, severe ARDS and mortality by LUS were calculated., Results: LUS had a negative correlation with oxygenation index (r=-0.755, P<0.001), a good positive correlation with APACHEII (r=0.504, P<0.001), SOFA (r=0.461, P<0.001) and CPIS (r=0.571, P<0.001) was found. LUS in the pulmonary ARDS group had a positive correlation with CPIS (r=0.399, P<0.05), and a positive correlation was found in non-pulmonary ARDS group (r=0.350, P<0.05), which indicated that the correlation in pulmonary ARDS was more satisfactory than that in non-pulmonary ARDS. LUS in the pulmonary ARDS group was significantly higher than that in non-pulmonary ARDS group (22.1±4.9 vs. 11.3±2.1, t=11.667, P<0.001); LUS in mild, moderate, severe ARDS groups was 9.9±1.7, 14.0±1.4, 23.6±4.1. The predictive value for mild ARDS by LUS was 7.0, sensitivity of 87.0%, specificity of 89.0%; that for moderate ARDS was 11.0, sensitivity of 89.0%, specificity of 87.0%; that for severe ARDS was 8.0, sensitivity of 90.0%, specificity of 88.5%. LUS was 24.3±3.8 in the death group, and 12.7±2.9 in the survival group. Area under ROC curve (AUC) was calculated, and the patients with LUS>19.0 had a high mortality, sensitivity for predicting death was 84.0%, and specificity of 89.0%., Conclusions: Bedside LUS, which is simple and easily available, could evaluate the changes in pulmonary ventilation area of ARDS, and its degree of severity, and prognosis including prediction of mortality of the patients.

Objective: To investigate the shape change index (SCI) of inferior vena cava (IVC) measured from subcostal area and right mid-axillary line through ultrasonography laying the foundation for future research about SCI and volume status., Methods: A total of 107 patients were enrolled in the Critical Care Medicine Department of Peking Union Medical College Hospital from December, 2014-January, 2015. The maximal diameter (MXD) and the minimal diameter (MID) were measured transversely from subcostal area and right mid-axillary line. The SCI was calculated., Results: Totally 47 patients (42 with spontaneous breathing and 5 on mechanical ventilation) achieved measurements on transversal plane from subcostal area and right mid-axillary line. (1) The internal diameter of IVC on longitudinal plane measured from subcostal area was statistically different from that measured from right mid-axillary line both at end inspiration (P=0.001) and at end expiration (P=0.027). (2) No difference were found in the SCI measured from subcostal and right mid-axillary line both at end inspiration and at expiration. (3) The internal diameter of IVC and the SCI measured on transversal plane from subcostal area correlated well with that measured from mid-axillary line both at end inspiration (SCI:r=0.866, P=0.000) and at end expiration (SCI: r=0.887, P=0.000)., Conclusions: Inferior vena cava internal diameters and the shape change index measured through ultrasonography on transversal planefrom subcostal area are correlated well with those from mid-axillary line. Measurements from the two sites can be replacedby each other.

Objective: To investigate the inferior vena cava internal diameter (IVCID) and inferior vena cava variability (IVCV) on longitudinal plane measured from subcostal area and right mid-axillary line through ultrasonography and to find out if the measuring site and different respiratory status were related to the IVCID and IVCV., Methods: A total of 127 patients were enrolled successively in Critical Care Medical Department of Peking Union Medical Hospital from November to December, 2013. IVCID and IVCV of patients on mechanical ventilation or with spontaneous breathing were measured longitudinally from subcostal area and right mid-axillary line., Results: (1) Totally 124 out of the 127 patients achieved measurement from right mid-axillary line, while only 83 patients achieved measurement from subcostal area. The difference was statistically significant (χ(2) = 74.42, P < 0.01) . Eighty-one patients can be measured from both sites, with 44 had spontaneous breathing and 37 on mechanical ventilation. (2)Whether in spontaneous or mechanically ventilated patients, IVCID measured from subcostal area was statistically different from right mid-axillary line measurement at both end expiration and end inspiration. (3) In mechanically ventilated patients with IVCID ≥ 2 cm measured from subcostal area at end expiration, no statistical difference was found between the IVCID from right mid-axillary line and from subcostal area[ (2.25 ± 0.32) cm vs (2.10 ± 0.12) cm, P = 0.083]. In spontaneous breathing patients with IVCID ≥ 2 cm measured from subcostal area at end expiration, there were significant differences between the IVCID from right mid-axillary line and from subcostal area at both end expiration and end inspiration. The IVCV between the two sites were also statistically different. In mechanically ventilated patients with IVCID ≤ 1.5 cm measured from subcostal area at end expiration, there were significant difference between the IVCID from right mid-axillary line and from subcostal area [ (1.58 ± 0.43) cm vs (1.09 ± 0.38) cm, P = 0.026]. In spontaneous breathing patients with IVCID ≤ 1.5 cm measured from subcostal area at end expiration, there were significant difference between the IVCID from right mid-axillary line and from subcostal area at both end expiration and end inspiration. The IVCV between the two sites were also statistically different. (4) Correlation analysis showed in mechanically ventilated patients, IVCID measured from right mid-axillary line at end expiration was correlated with the IVCID measured from subcostal area at end expiration(r = 0.565, P = 0.000). In spontaneous breathing patients, IVCID measured at end expiration from right mid-axillary line was correlated with the IVCID measured from subcostal area (r = 0.526, P = 0.000) . IVCID measured at end inspiration from right mid-axillary line was correlated with the IVCID measured from subcostal area (r = 0.454, P = 0.002). IVCV measured from right mid-axillary line was correlated with IVCV measured from subcostal area (r = 0.513, P = 0.000)., Conclusions: Inferior vena cava internal diameter and variability measured longitudinally through ultrasonography from subcostal area is different with measurements from right mid-axillary line. Measurements from the two sites are not replaceable with each other. Further studies are needed before the clinical use of inferior vena cava internal diameter and variability measured from right mid-axillary line.

Objective: To investigate the effect of non invasive cardiac output monitoring (NICO) system in pig model with acute respiratory distress syndrome (ARDS), and to provide experimental basis for clinical application., Methods: Eleven anaesthetized and ventilated ARDS male pig models were induced by intravenously infusing 0.2 mL/kg oleic acid. Lung recruitment was condocted by pressure control ventilation on pigs with ARDS. The optimal positive end-expiratory pressure (PEEP) was determined by optimal dead space fraction [the ratio of dead space to tidal volume (VD/VT)]. Cardiac output (CO) was determined by NICO, the respiratory function was monitored, and the VD/VT, dynamic compliance (Cdyn), oxygenation index (PaO₂/FiO₂), the volume of alveolar ventilation (Valv) and arterial blood oxygen saturation (SaO₂) were recorded before infusing oleic acid, after stabilization of ARDS model and at optimal PEEP level, and the intrapulmonary shunt fraction (Qs/Qt) was calculated. CO was also determined by application of pulse indicated continuous cardiac output (PiCCO), and the linear regression analysis between CO determined by NICO and CO determined by PiCCO was conducted., Results: Seven experimental ARDS pigs model were successfully established. The optimal PEEP identified by the lowest VD/VT method was (15.71 ± 1.80) cmH₂O (1 cmH₂O = 0.098 kPa). Compared with before infusing oleic acid, VD/VT and Qs/Qt after stabilization of ARDS model were significantly increased [VD/VT: (72.29 ± 8.58)% vs. (56.00 ± 11.06)%, Qs/Qt: (21.04 ± 15.05)% vs. (2.00 ± 1.32)%, both P<0.05], and SaO₂and Valv were significantly decreased [SaO₂: 0.888 ± 0.108 vs. 0.999 ± 0.053, Valv (mL): 92.06 ± 35.22 vs. 146.11 ± 45.43, both P<0.05]. VD/VT, Qs/Qt, SaO₂and Cdyn at optimal PEEP level were improved to the levels before infusing oleic acid [(61.07 ± 9.30)%, (3.21 ± 6.10)%, 0.989 ± 0.025, (117.14 ± 41.14)mL]. Cdyn and PaO₂/FiO₂after stabilization of ARDS model were significantly lowered compared with those before infusing oleic acid [Cdyn (mL/cmH₂O): 14.43 ± 5.50 vs. 38.14 ± 6.72, PaO₂/FiO₂(mmHg, 1 mmHg = 0.133 kPa): 78.71 ± 23.22 vs. 564.37 ± 158.85, both P < 0.05]. Cdyn and PaO₂/FiO₂at optimal PEEP level [(19.71 ± 4.86)%, (375.49 ± 141.30) mmHg] were elevated compared with the levels after stabilization of ARDS model (both P <0 .05), but still lower than those before infusing oleic acid (both P < 0.05). Compared with the levels after stabilization of ARDS model, CO at optimal PEEP level showed obvious decrease from (4.18 ± 2.46) L/min to (3.95 ± 2.69) L/min without significant difference (P > 0.05). There was linear correlation between CO determined by NICO and CO determined by PiCCO (r²=0.925, P < 0.001)., Conclusions: NICO technique provides a useful and accurate non invasive estimation of CO and respiratory function.VD/VT provided by NICO can titrate the optimal PEEP in patients with ARDS.

Objective: To investigate the effects of Peking Union Medical College Hospital (PUMCH) Critical Ultrasonic Management (PCUM) scheme on the etiological diagnosis and treatment decisions for the patients with dyspnea and/or hemodynamic instability in ICU., Methods: Patients who suffered from dyspnea and/or hemodynamic instability in PUMCH ICU were included in this study. The time to preliminary diagnosis, time to final diagnosis, diagnostic accuracy, time to accurate treatment, time to consultation with other specialties, time to other examinations were recorded., Results: A total of 129 patients were included in this study. In patients applied with PCUM scheme, time to preliminary diagnosis, final diagnosis and accurate treatment were (15 ± 6)min, (65 ± 16)min and (34 ± 14)min respectively, and the accuracy of diagnosis was 93.0%. PCUM patients had high sensitivity and specificity for the diagnosis of acute respiratory distress syndrome (ARDS)(sensitivity 90.2%/specificity 93.6%), distributive shock(sensitivity 92.5%/specificity 93.6%) and pulmonary edema(sensitivity 93.4%/specificity 92.7%) etc., Conclusions: The PCUM scheme is associated with short time to preliminary diagnosis and high diagnostic accuracy and could improve the treatment for patients with dyspnea and/or hemodynamic instability.