Ultrasound re-recruitment score for lung recruitment end point determination in children with prds

Abstract

This invention discloses a method for determining the lung recruitment endpoint using the PARDS ultrasound regasification score in children, relating to the field of pediatric critical respiratory support therapy. It solves the technical problem of existing technologies being unable to perform real-time dynamic zonal assessment of alveolar recruitment status in different lung regions, especially gravity-dependent areas, which easily leads to inadequate lung recruitment treatment. This invention performs standardized zonal ultrasound examination of the child's lungs during lung recruitment, employing a graded and quantified ultrasound regasification scoring system to assign values ​​to the lung ventilation level of each examined region. The total ultrasound regasification score is calculated by summing these values. With the core condition of continuously increasing PEEP and no further increase in the total score after plateau pressure, this invention can achieve objective and accurate determination of the lung recruitment endpoint, ensuring the adequacy and safety of lung recruitment treatment. It is applicable to the management of mechanical ventilation in children with acute respiratory distress syndrome.

Description

Technical Field

[0001] This invention relates to the field of pediatric critical respiratory support therapy technology, specifically a method for determining the lung recruitment endpoint in pediatric PARDS ultrasound regasification score. Background Technology

[0002] Childhood acute respiratory distress syndrome (PARDS) is a clinical syndrome caused by multiple etiologies. Its core pathophysiological change is the collapse of numerous alveoli, leading to a decrease in lung volume and functional residual capacity, which in turn causes refractory hypoxemia. Even after treating the primary disease and implementing lung-protective ventilation strategies, some children still experience persistent hypoxemia. In such cases, lung recruitment therapy is often considered clinically. The goal of lung recruitment therapy is to reopen collapsed alveoli by increasing airway pressure and maintaining alveolar patency with appropriate positive end-expiratory pressure, thereby improving oxygenation and reducing lung injury.

[0003] During lung recruitment, ventilator settings are significantly higher than usual, necessitating dynamic monitoring and assessment of lung recruitment adequacy and the resulting alveolar overinflation. Early clinicians attempted to use the oxygenation index (P / F ratio) as an indicator of lung recruitment adequacy. Previous studies found a 1:1 exchange ratio between PCO2 and PO2 in the alveolar cavity at 100% oxygen concentration, suggesting that PO2 + PCO2 ≥ 400 mmHg represents the endpoint of lung recruitment, while PO2 + PCO2 ≤ 380 mmHg indicates widespread alveolar collapse. Other methods for assessing lung recruitment adequacy include the PV curve method, lung CT scans, and lung ultrasound. However, the PV curve method requires deep sedation and muscle relaxation to reduce the respiratory rate to 10 breaths / min, which can easily lead to severe carbon dioxide retention in pediatric patients, and it cannot distinguish between alveolar recruitment and alveolar overinflation. While lung CT is the gold standard for assessing lung re-expansion, it requires transferring critically ill children out of the PICU, necessitating multiple repetitions, leading to a gradual accumulation of transfer risks, potential harm from high-dose radiation exposure, and high examination costs. Clinically, there is a need for bedside, repeatable, safe, highly sensitive, and highly specific examination methods, making lung ultrasound an important option. Lung ultrasound primarily focuses on the ultrasound characteristics of two types of PARDS: interstitial lung syndrome and alveolar syndrome (pulmonary consolidation). The former presents as a rocket sign, while the latter presents as a fragmentation sign or histoid degeneration sign. Summary of the Invention

[0004] The purpose of this invention is to overcome the shortcomings of the prior art and provide a method for determining the lung recruitment endpoint of the PARDS ultrasound regasification score in children. By using zonal ultrasound exploration and dynamic changes in ultrasound regasification score, it can achieve accurate assessment of the alveolar recruitment status of the entire lung, including gravity-dependent areas, so as to solve the technical problem that the prior art cannot determine whether local alveoli have truly recruited.

[0005] To solve the above-mentioned technical problems, the present invention provides the following technical solution: a method for determining the lung recruitment endpoint using PARDS ultrasound regasification scoring in children, the method comprising the following steps: Step 1: During lung re-expansion, after the preset PEEP adjustment is completed and the lungs reach a stable state, use an ultrasound probe to perform a zoned exploration of the child's lungs. The zoned exploration includes the exploration of the bilateral upper BLUE points and lower BLUE points when the child is in a supine position, and the exploration of the bilateral PLAPS points after the affected side of the body is elevated. Step 2: Based on the ultrasound image characteristics of each exploration point, assign an ultrasound regasification score to each exploration point according to the preset scoring rules. The ultrasound regasification score is used to quantify the lung ventilation level of the area. Step 3: Summarize the ultrasonic regasification scores of all exploration points and calculate the total ultrasonic regasification score under the current state; Step 4: Compare the total ultrasound regasification score in the current state with the total ultrasound regasification score in the stable state after the previous PEEP increase. When the total ultrasound regasification score no longer increases, the lung recruitment endpoint is determined, and the airway pressure at this time is recorded as the lung opening pressure.

[0006] By conducting zoned exploration of the lungs and dynamically calculating the total ultrasound regasification score, and taking the point at which the score no longer increases as the endpoint of lung re-expansion, the degree of improvement in the overall lung ventilation level can be objectively quantified, and the lung re-expansion endpoint can be accurately determined.

[0007] Furthermore, in step one, the six exploration points involved in the partition exploration are specifically the upper left BLUE point, the lower left BLUE point, the left PLAPS point, the upper right BLUE point, the lower right BLUE point, and the right PLAPS point.

[0008] By clearly defining six specific ultrasound examination points, it is possible to ensure comprehensive coverage of all lobes of both lungs, especially the gravity-dependent area of ​​the back that is difficult to assess using traditional methods, thereby achieving a complete assessment of the ventilation status of the entire lungs.

[0009] Furthermore, in step two, the preset scoring rule is: to assign points based on the degree of improvement in lung ventilation reflected by the change of ultrasound image features from one sign to another, specifically including: when the ultrasound sign changes from B1 to N, 1 point is assigned. When the ultrasound sign changes from B2 to N, a score of 3 is assigned. When the ultrasound sign changes from C to N, a score of 5 is assigned. When the ultrasound findings change from B2 to B1, 1 point is awarded. When the ultrasound findings change from C to B1, a score of 3 is assigned. When the ultrasound findings change from C to B2, 1 point is awarded. In this context, N represents normal ventilation (normal vaporization level), B1 represents moderate reduced ventilation (multiple B-lines with clear boundaries, regular distribution and spacing ≥7mm or irregular distribution), B2 represents severe reduced ventilation (diffusely distributed, continuous B-lines), and C represents pulmonary consolidation. The ultrasound revaporization score is the score corresponding to each of the above transformation pathways, used to quantify the degree of improvement in pulmonary ventilation.

[0010] Furthermore, in step three, the total ultrasonic regasification score in the current state is calculated by summing the values ​​assigned to all six probe points.

[0011] By summing the scores of the six exploration points, discrete ultrasound information from multiple regions can be integrated into a quantitative total score, providing clinicians with a numerical indicator that intuitively reflects the overall ventilation status of the whole lung.

[0012] Furthermore, the PEEP increase during lung recruitment is performed according to a preset lung recruitment protocol, which is as follows: In pressure-controlled ventilation mode, a first preset pressure value is used as the initial treatment pressure and maintained for a first preset time. Then, PEEP and plateau pressure are simultaneously increased to a second preset pressure value and maintained for a second preset time. This increase and maintenance process is repeated until the lung recruitment endpoint is reached or the preset plateau pressure upper limit is reached.

[0013] By employing a lung recruitment protocol that involves gradually increasing pressure and maintaining stability before reassessment, sufficient pressure and time can be provided for alveolar opening while ensuring hemodynamic stability in the child, thus achieving an orderly and controllable lung recruitment process.

[0014] Furthermore, the first preset pressure value is PEEP equal to 15cmH2O and plateau pressure equal to 30cmH2O, the first preset time is 8 minutes, the second preset pressure value is PEEP equal to 20cmH2O and plateau pressure equal to 35cmH2O, the second preset time is 8 minutes, and the preset upper limit of plateau pressure is 50cmH2O.

[0015] By setting specific initial pressure, increment, maintenance time, and upper limit of safe pressure, it is possible to balance lung recruitment effectiveness and safety under standardized operating procedures, avoiding excessive alveolar over-expansion or barotrauma due to excessive pressure.

[0016] Furthermore, after determining that the lung recruitment endpoint has been reached, a PEEP titration step is also included: starting from the lung opening pressure, PEEP is gradually reduced, and the total ultrasound regasification score is rechecked after each reduction. The lowest PEEP value that maintains the total ultrasound regasification score without decreasing and the peripheral blood oxygen saturation is not lower than the preset threshold is determined as the final PEEP.

[0017] By gradually reducing PEEP after successful lung recruitment and simultaneously monitoring changes in ultrasound scores, the lowest pressure value that maintains alveolar patency without recollapse can be found, thus achieving an individualized optimal PEEP setting.

[0018] Furthermore, the step size for gradually reducing PEEP is 2 cmH2O, and after each reduction, it is maintained for a fifth preset time before a re-examination is performed. The preset threshold for peripheral blood oxygen saturation is 97%.

[0019] By setting a down-adjustment step size of 2 cmH2O and a peripheral blood oxygen saturation threshold of 97%, ideal PEEP can be steadily titrated while ensuring stable oxygenation in children, avoiding alveolar collapse due to sudden pressure drop.

[0020] Furthermore, the formula for calculating the total ultrasonic regasification score is as follows: Where n is the total number of exploration points, which is fixed at 6, and i is the index number of the exploration point. The ultrasonic regasification score for the i-th exploration point is determined by the ultrasonic image characteristics of that point and can be 1, 3, or 5. The definition is: the ultrasonic regasification score. The value is determined based on the transformation path of the ultrasound image features at the exploration point, and the specific rules are as follows: When the ultrasound sign changes from B1 to N ; When the ultrasound sign changes from B2 to N ; When the ultrasound sign changes from C to N ; When the ultrasound findings change from B2 to B1 ; When the ultrasound findings change from C to B1 ; When the ultrasound findings change from C to B2 .

[0021] In this system, N represents normal ventilation, B1 represents moderate reduced ventilation, B2 represents severe reduced ventilation, and C represents pulmonary consolidation. By using a specific summation formula to accumulate the ultrasound scores from the six exploration points, the calculation method for the total ultrasound regasification score can be rigorously defined mathematically, providing an objective and unified quantitative basis for the entire lung recruitment endpoint determination system.

[0022] Compared with existing technologies, this method for determining the lung recruitment endpoint using the PARDS ultrasound regasification scoring system in children has the following advantages: I. This invention utilizes standardized zonal ultrasound examination of both lungs, focusing on the gravity-dependent areas of the back that are difficult to assess using traditional methods. Combined with a graded and quantified ultrasound regasification scoring system, it enables real-time, dynamic, and precise quantitative assessment of the alveolar recruitment status in all lung regions. This effectively overcomes the shortcomings of existing technologies in monitoring the recruitment status of local alveoli, especially in gravity-dependent areas, thus avoiding the problem of systemic oxygenation indicators reaching the target while local lung lobes remain collapsed. It achieves objective and accurate determination of the lung recruitment endpoint, fully ensuring the effectiveness of lung recruitment treatment and improving the prognosis of children.

[0023] Second, this invention, through a step-by-step pressure control scheme adapted to the ultrasound assessment process and an individualized PEEP titration process after determining the lung recruitment endpoint, can achieve standardization and normalization of the entire lung recruitment operation process, effectively reducing judgment bias between different operators and ensuring the repeatability of assessment results. Thus, the entire operation can be completed at the bedside without relying on large imaging equipment or complex monitoring instruments, greatly improving clinical applicability. At the same time, while ensuring the lung recruitment effect, it reduces the risk of complications such as barotrauma, and is suitable for the application needs of pediatric critical care clinical practice.

[0024] Other advantages, objectives and features of the invention will be set forth in part in the description which follows, and in part will be apparent to those skilled in the art from the following examination or study, or may be learned from the practice of the invention. Attached Figure Description

[0025] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the accompanying drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are merely some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without any creative effort.

[0026] Figure 1 This is a schematic diagram of the ultrasonic regasification scoring rules of the present invention; Figure 2This invention provides a grading and corresponding scoring atlas of pulmonary ventilation ultrasound signs. Figure 3 This is a flowchart of the lung recruitment endpoint determination and PEEP titration operation of the present invention. Detailed Implementation

[0027] To further illustrate the technical means and effects of the present invention in achieving its intended purpose, the following detailed description of the specific implementation methods, structures, features, and effects of the present invention, in conjunction with the accompanying drawings and preferred embodiments, is provided below.

[0028] Example This embodiment is applied to pediatric intensive care unit patients who meet the diagnostic criteria for acute respiratory distress syndrome and are on invasive mechanical ventilation. It fully implements the entire process of the PARDS ultrasound regasification scoring method for determining the lung recruitment endpoint. The equipment used in this embodiment includes a pediatric-specific invasive ventilator with pressure-controlled ventilation mode, a portable bedside ultrasound device equipped with a 7.5MHz linear array ultrasound probe, a multi-parameter vital signs monitor, and an arterial blood gas analyzer.

[0029] Lung recruitment should be performed when the child's vital signs are relatively stable. Therefore, this embodiment first completes the baseline assessment and condition preparation of the child before initiating the procedure. Specifically, the child is first confirmed to meet the diagnostic criteria for PARDS, with mechanical ventilation duration less than 72 hours and baseline PEEP level in the range of 5 to 15 cmH2O. Children with hemodynamic instability, severe left or right ventricular dysfunction, vasoactive drug dose adjustments exceeding 50% within the past 6 hours, blood lactate levels greater than 2 mmol / L, bronchiolitis, congenital diaphragmatic hernia, restrictive lung disease, pulmonary fibrosis, continuous inhalation of nitric oxide or oral sildenafil, severe traumatic brain injury, or those using extracorporeal membrane oxygenation (ECMO) life support are excluded.

[0030] In this embodiment, before initiating the lung recruitment procedure, the inhaled oxygen concentration is adjusted to 100% and maintained for five minutes before proceeding with the subsequent procedures. Throughout the lung recruitment procedure, the child is maintained in a state of deep sedation and muscle relaxation by adjusting the dosage of sedative and muscle relaxant medications. Midazolam is used as the sedative at a rate of 2 to 8 μg per kilogram per minute, and rocuronium bromide is used as the muscle relaxant at a rate of 1.0 mg per kilogram per hour, maintaining a Ramsay score of 4 to 5. Throughout the procedure, the child's heart rate, blood pressure, pulse oximetry, and end-tidal carbon dioxide levels are continuously monitored using a multi-parameter vital signs monitor. If the heart rate increases or decreases by more than 20 beats per minute, a new arrhythmia occurs, the systolic blood pressure decreases by more than 20 mmHg, or the pulse oximetry decreases by more than 5%, the lung recruitment procedure is immediately terminated.

[0031] Specifically, this embodiment employs pressure-controlled ventilation mode to perform stepwise lung recruitment, with the entire process divided into a baseline segment and a lung recruitment segment. During the baseline segment, volume-controlled ventilation mode is used to deliver air at a low flow rate, with a tidal volume set at 6 mL per kilogram of standard body weight. The PV curve monitoring function built into the ventilator is used to identify the low inflection point, providing a baseline reference for subsequent PEEP settings.

[0032] For lung recruitment, the initial treatment pressure was set at PEEP of 15 cmH2O and plateau pressure of 30 cmH2O. Under deep sedation and muscle relaxation, the respiratory rate was adjusted to 20-25 breaths per minute, the inspiratory time to 1.2 seconds, and the inhaled oxygen concentration was maintained at 100% for 8 minutes. After the child's ventilation and hemodynamics stabilized, the first lung ultrasound and arterial blood gas analysis were performed, and the baseline ultrasound regasification score and blood gas parameters were recorded.

[0033] To achieve orderly and controllable alveolar recruitment, this embodiment employs a stepwise pressurization method by simultaneously increasing PEEP and plateau pressure. Specifically, after assessing the previous pressure level, PEEP and plateau pressure are simultaneously increased by 5 cmH2O and maintained for 8 minutes. After the ventilation stabilizes for 2 minutes, lung ultrasound and arterial blood gas analysis are performed again, and the total ultrasound regasification score is calculated for the current state. This procedure of increasing pressure, maintaining stability, ultrasound assessment, and score calculation is repeated until the lung recruitment endpoint is reached, or the plateau pressure reaches the safe upper limit of 50 cmH2O. If the lung recruitment endpoint is not reached even after the plateau pressure reaches 50 cmH2O, the lung recruitment operation is immediately stopped to avoid barotrauma.

[0034] like Figure 1 As shown, the ultrasound regasification scoring rule used in this embodiment is the dynamic improvement scoring method, which assigns a score based on the degree of improvement in lung ventilation reflected by the change of ultrasound image features from one sign to another. The specific rules are as follows: 1 point is assigned when the ultrasound sign changes from B1 to N; 3 points are assigned when the ultrasound sign changes from B2 to N; 5 points are assigned when the ultrasound sign changes from C to N; 1 point is assigned when the ultrasound sign changes from B2 to B1; 3 points are assigned when the ultrasound sign changes from C to B1; and 1 point is assigned when the ultrasound sign changes from C to B2. Here, N represents normal ventilation, B1 represents moderate decreased ventilation, B2 represents severe decreased ventilation, and C represents pulmonary consolidation.

[0035] Specifically, the ultrasound examination is completed in two steps. The first step is a supine examination. The child maintains a standard supine position, and the ultrasound probe is used to examine the upper and lower BLUE points bilaterally. The upper BLUE point is located at the intersection of the midclavicular line and the second intercostal space, and the lower BLUE point is located at the intersection of the anterior axillary line and the fifth intercostal space, corresponding to the ventilation status assessment of the upper and middle lobes of both lungs, respectively. The second step is PLAPS point examination. The child's ipsilateral body is raised one by one to fully expose the ipsilateral back, and the ultrasound probe is placed at the intersection of the posterior axillary line and the upper edge of the diaphragm, i.e., the PLAPS point, to complete the bilateral PLAPS point examination, corresponding to the ventilation status assessment of the gravity-dependent areas of the lower lobes of both lungs.

[0036] Ultrasound examinations at each site were performed at the end of expiration, acquiring clear two-dimensional ultrasound images. The ultrasound image characteristics of each site were observed and recorded, including the pleural line status, A-line distribution, B-line morphology and distribution, and signs of pulmonary consolidation, providing a basis for subsequent ultrasound regasification scoring. Ultrasound images for at least three consecutive respiratory cycles were acquired at each site to ensure the accuracy and repeatability of image characteristics and avoid scoring errors caused by differences in respiratory phases. All ultrasound examinations were performed by uniformly trained sonographers, maintaining the ultrasound probe perpendicular to the chest wall during the procedure to ensure the sound beam was perpendicularly incident on the pleural line and obtain clear ultrasound images.

[0037] like Figure 2 As shown, this embodiment uses a three-level grading rule of 1 to 5 points to quantify the ultrasound image features of each exploration point. The ultrasound regasification score is used to quantify the lung ventilation level of the corresponding area. The higher the score, the more severe the lung ventilation loss in that area.

[0038] Specifically, the scoring rule adopted in this embodiment is the dynamic improvement scoring method, which assigns a score based on the degree of improvement in lung ventilation reflected by the change of ultrasound image features from one sign to another. The specific rules are as follows: when the ultrasound sign changes from B1 to N, 1 point is assigned; when the ultrasound sign changes from B2 to N, 3 points are assigned; when the ultrasound sign changes from C to N, 5 points are assigned; when the ultrasound sign changes from B2 to B1, 1 point is assigned; when the ultrasound sign changes from C to B1, 3 points are assigned; when the ultrasound sign changes from C to B2, 1 point is assigned. In this system, N represents normal ventilation, which is represented by a clear A-line on ultrasound, indicating normal lung ventilation in that area. B1 represents moderate hypoventilation, which is represented by multiple well-defined, regularly distributed B-lines with a spacing of ≥7mm or irregularly distributed on ultrasound. B2 represents severe hypoventilation, which is represented by diffusely distributed, continuous B-lines on ultrasound. C represents lung consolidation, which is represented by fragmentation or tissue-like changes on ultrasound. The ultrasound regasification score corresponds to the scores for each of these transformation pathways and is used to quantify the degree of improvement in lung ventilation. The scores for all exploration points are based on a comparison with ultrasound findings at baseline (ZEEP or pre-lung recruitment) to reflect the ventilation improvement effect brought about by the lung recruitment procedure.

[0039] The scoring and assignment rules in this embodiment are independently completed by two ultrasound physicians who have received standardized training. If there are discrepancies in the scores obtained by the two physicians, a consensus is reached through joint review of the images, ensuring the objectivity and repeatability of the scoring results and eliminating judgment bias between different operators. All scoring results are simultaneously recorded in the child's treatment file, forming a complete correspondence with the corresponding ventilator parameters and blood gas analysis results at the corresponding pressure levels, providing comprehensive data support for subsequent dynamic comparative analysis.

[0040] Specifically, after assigning scores to all six exploration points, the ultrasonic regasification scores of all exploration points are summarized to calculate the total ultrasonic regasification score under the current condition. The formula for calculating the total ultrasonic regasification score is as follows: The following is a detailed explanation of each parameter in the formula.

[0041] The total ultrasound regasification score, representing the current state, is a quantitative indicator reflecting the overall ventilation status of the child's lungs. The higher the score, the more severe the overall ventilation loss.

[0042] The summation operator represents the summation of all values ​​within a specified range in the formula.

[0043] i is the index number of the exploration point, used to identify each lung exploration point that has been explored and scored in sequence. The index number starts from 1 and increases sequentially.

[0044] n represents the total number of exploration points, which is a fixed value of 6 in this embodiment, corresponding to six exploration points in both lungs, ensuring that the coverage of the whole lung assessment is fixed and uniform.

[0045] Let be the ultrasonic revaporization score for the i-th exploration point. Its value is determined based on the transformation path of the ultrasonic image features at that exploration point, according to the following rules: When the ultrasound sign changes from B1 to N ; When the ultrasound sign changes from B2 to N ; When the ultrasound sign changes from C to N ; When the ultrasound findings change from B2 to B1 ; When the ultrasound findings change from C to B1 ; When the ultrasound findings change from C to B2 .

[0046] N represents normal ventilation, which is represented by a clear A-line on ultrasound, indicating normal lung ventilation in that area; B1 represents moderate hypoventilation, which is represented by multiple well-defined, regularly distributed B-lines with a spacing of ≥7mm or irregularly distributed on ultrasound; B2 represents severe hypoventilation, which is represented by diffusely distributed, continuous B-lines on ultrasound; and C represents pulmonary consolidation, which is represented by fragmentation or tissue-like changes on ultrasound.

[0047] By using the above summation formula, the dynamic improvement scores of the six exploration points are integrated into a unified quantitative total score, which intuitively reflects the overall improvement in ventilation of the whole lung and provides an objective numerical basis for determining the lung recruitment endpoint.

[0048] like Figure 3 As shown, this embodiment achieves accurate determination of the lung recruitment endpoint by dynamically comparing the changing trend of the total ultrasound regasification score and independently assessing the ultrasound signs in the gravity-dependent area.

[0049] Specifically, after calculating the total echocardiogram regasification score at the current pressure level, it is compared with the total echocardiogram regasification score at a stable state after the previous PEEP increase to assess changes in whole-lung ventilation. When the total echocardiogram regasification score no longer increases after consecutive PEEP increases, it is preliminarily determined that the lung recruitment endpoint has been reached.

[0050] When the lung recruitment endpoint is reached, record the airway pressure at this point as the lung opening pressure, stop increasing the airway pressure, and proceed to the subsequent PEEP titration step. If, during pressure increase, the plateau pressure reaches 50 cmH2O but the above lung recruitment endpoint criteria are still not met, immediately stop increasing the pressure to avoid alveolar overinflation and barotrauma. If the child's vital signs exceed the preset safe range during the procedure, also immediately terminate the procedure, restore the ventilator parameters to the baseline safe level, and ensure the child's safety.

[0051] Specifically, after determining that the lung recruitment endpoint has been reached, an individualized PEEP titration procedure is performed to determine the optimal PEEP value for maintaining alveolar patency. The titration procedure starts with the PEEP value corresponding to the lung opening pressure and gradually decreases the PEEP, with each decrease increment being 2 cmH2O. After each PEEP decrease, the ventilation status is maintained for 5 minutes, and a full lung six-zone ultrasound examination is performed again to calculate the total ultrasound regasification score under the current condition, while simultaneously monitoring the child's peripheral blood oxygen saturation.

[0052] The endpoint determination criterion for PEEP titration is the lowest PEEP value that maintains the total echocardiography-regasification score without decreasing and peripheral blood oxygen saturation above 97%. This PEEP value is determined as the final optimal PEEP value and used for subsequent mechanical ventilation treatment of the child. During PEEP titration, if the total echocardiography-regasification score increases or peripheral blood oxygen saturation falls below 97%, the PEEP is immediately adjusted back to the previous stable level. After confirming stable ventilation, the final PEEP value is locked. After locking the optimal PEEP value, the inhaled oxygen concentration is gradually reduced to the minimum level that maintains peripheral blood oxygen saturation above 97%, completing the entire lung recruitment and PEEP setting process.

[0053] The entire process in this embodiment follows standardized execution procedures, with corresponding recording requirements for each step. All operational data, ultrasound images, scoring results, and blood gas parameters are fully preserved to ensure the traceability of the procedure. This embodiment achieves precise guidance throughout the lung re-expansion process in children with PARDS through standardized zonal exploration, quantitative scoring, dynamic comparison, and endpoint determination, ensuring the safety and repeatability of the procedure.

[0054] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present invention. Any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the scope of the present invention.

Claims

1. A method for determining the lung recruitment endpoint using the PARDS ultrasound revaporization score in children, characterized in that... The method includes the following steps: Step 1: During lung re-expansion, after the preset PEEP adjustment is completed and the lungs reach a stable state, use an ultrasound probe to perform a zoned exploration of the child's lungs. The zoned exploration includes the exploration of the bilateral upper BLUE points and lower BLUE points when the child is in a supine position, and the exploration of the bilateral PLAPS points after the affected side of the body is elevated. Step 2: Based on the ultrasound image characteristics of each exploration point, assign an ultrasound regasification score to each exploration point according to the preset scoring rules. The ultrasound regasification score is used to quantify the lung ventilation level of the area. Step 3: Summarize the ultrasonic regasification scores of all exploration points and calculate the total ultrasonic regasification score under the current state; Step 4: Compare the total ultrasound regasification score in the current state with the total ultrasound regasification score in the stable state after the previous PEEP increase. When the total ultrasound regasification score no longer increases, the lung recruitment endpoint is determined, and the airway pressure at this time is recorded as the lung opening pressure.

2. The method for determining the lung recruitment endpoint using the PARDS ultrasound regasification scoring system for children according to claim 1, characterized in that, In step one, the six exploration points involved in the partition exploration are specifically the upper left BLUE point, the lower left BLUE point, the left PLAPS point, the upper right BLUE point, the lower right BLUE point, and the right PLAPS point.

3. The method for determining the lung recruitment endpoint using the PARDS ultrasound regasification scoring system for children according to claim 1, characterized in that, In step two, the preset scoring rule is: to assign a score based on the degree of improvement in lung ventilation reflected by the change of ultrasound image features from one sign to another, specifically including: when the ultrasound sign changes from B1 to N, 1 point is assigned. When the ultrasound sign changes from B2 to N, a score of 3 is assigned. When the ultrasound sign changes from C to N, a score of 5 is assigned. When the ultrasound findings change from B2 to B1, 1 point is awarded. When the ultrasound findings change from C to B1, a score of 3 is assigned. When the ultrasound findings change from C to B2, 1 point is awarded. Wherein, N represents normal ventilation, B1 represents moderate reduced ventilation, B2 represents severe reduced ventilation, and C represents pulmonary consolidation. The ultrasound regasification score is used to quantify the degree of improvement in pulmonary ventilation.

4. The method for determining the lung recruitment endpoint using the PARDS ultrasound regasification scoring system for children according to claim 1, characterized in that, In step three, the total ultrasonic regasification score under the current state is calculated by summing the values ​​assigned to all six probe points.

5. The method for determining the lung recruitment endpoint using the PARDS ultrasound regasification scoring system for children according to claim 1, characterized in that, The PEEP increase during lung recruitment is performed according to a preset lung recruitment protocol, which is as follows: In pressure-controlled ventilation mode, a first preset pressure value is used as the initial treatment pressure and maintained for a first preset time. Then, PEEP and plateau pressure are increased synchronously to a second preset pressure value and maintained for a second preset time. This increase and maintenance process is repeated until the lung recruitment endpoint is reached or the preset plateau pressure upper limit is reached.

6. The method for determining the lung recruitment endpoint using the PARDS ultrasound regasification scoring system for children according to claim 5, characterized in that, The first preset pressure value is PEEP equal to 15cmH2O and plateau pressure equal to 30cmH2O, the first preset time is 8 minutes, the second preset pressure value is PEEP equal to 20cmH2O and plateau pressure equal to 35cmH2O, the second preset time is 8 minutes, and the preset upper limit of plateau pressure is 50cmH2O.

7. The method for determining the lung recruitment endpoint using the PARDS ultrasound regasification scoring system for children according to claim 1, characterized in that, After determining that the lung recruitment endpoint has been reached, a PEEP titration step is also included: starting from the lung opening pressure, PEEP is gradually reduced, and the total ultrasound regasification score is rechecked after each reduction. The lowest PEEP value that maintains the total ultrasound regasification score without decreasing and the peripheral blood oxygen saturation is not lower than the preset threshold is determined as the final PEEP.

8. The method for determining the lung recruitment endpoint using the PARDS ultrasound regasification scoring system for children according to claim 7, characterized in that, The step size for gradually reducing PEEP is 2 cmH2O. After each reduction, the PEEP is maintained for a fifth preset time before a retest is performed. The preset threshold for peripheral blood oxygen saturation is 97%.

9. The method for determining the lung recruitment endpoint using the PARDS ultrasound regasification scoring system for children according to claim 1, characterized in that, The formula for calculating the total ultrasonic regasification score is as follows: Where n is the total number of exploration points, which is fixed at 6, and i is the index number of the exploration point. The ultrasonic regasification score for the i-th exploration point is determined by the ultrasonic image characteristics of that point and can be 1, 3, or 5. The definition is: the ultrasonic regasification score. The value is determined based on the transformation path of the ultrasound image features at the exploration point, and the specific rules are as follows: When the ultrasound sign changes from B1 to N ; When the ultrasound sign changes from B2 to N ; When the ultrasound sign changes from C to N ; When the ultrasound findings change from B2 to B1 ; When the ultrasound findings change from C to B1 ; When the ultrasound findings change from C to B2 .

Images