РАЗДЕЛЬНАЯ КОМБИНИРОВАННАЯ МЕХАНИЧЕСКАЯ И ВЫСОКОЧАСТОТНАЯ ВЕНТИЛЯЦИЯ ЛЁГКИХ У ПЕДИАТРИЧЕСКИХ ПАЦИЕНТОВ ПРИ ТОРАКАЛЬНЫХ ВМЕШАТЕЛЬСТВАХ

LIST OF ABBREVIATIONS

BP - blood pressure

ADH - antidiuretic hormone

ACTH - adrenocorticotropic hormone

SVM - secondary brain injury

ICH - intracranial hypertension

ICP - intracranial pressure

GM - brain

DAP - diffuse axonal injury

DIC - disseminated intravascular coagulation

road traffic accident

IVL - artificial lung ventilation

IT - intensive care

KOS - acid-base state

CTMG - computed tomography of the brain

LDH - lactate dehydrogenase

LBF - linear velocity of blood flow

LSMK - linear velocity of cerebral blood flow

MK - cerebral blood flow

NRTC - Nizhny Novgorod Regional Trauma Center

ICU - intensive care unit

BCC - volume of circulating blood

ARDS - acute respiratory distress syndrome

PON - multiple organ failure

SAH - subarachnoid hemorrhage

MCA - middle cerebral artery

MODS - multiple organ failure syndrome

CTBI - combined craniocerebral injury

TKDG - transcranial dopplerography

feasibility study - thromboembolic complications

tSAH - traumatic subarachnoid hemorrhage

TSCHMT - severe concomitant traumatic brain injury

STBI - severe traumatic brain injury

CVP - central venous pressure

CNS - central nervous system

CPP - cerebral perfusion pressure

CRH - central district hospital

RR - respiratory rate

HR - heart rate

TBI - traumatic brain injury

GCS - Glasgow Coma Scale

EMHPS - ethylmethylhydrocypyridine succinate

APACHE II - Acute Physiology And Chronic Health Evaluation II

BE - deficiency or excess of buffer bases

pCO2 - partial pressure of carbon dioxide

PI - pulsation index

pH - the level of hydrogen content in the body and total acidity

pO2 - partial pressure of oxygen

RI - resistance index

Vm - average blood flow velocity

Vmax - systolic blood flow velocity

Vmin - diastolic blood flow velocity

VBG – venous blood gas

HF MV – high frequency mechanical ventilation

TV – tidal volume

HF JLV – high frequency jet lung ventilation

ARDS – acute respiratory distress syndrome

ALI – actute lung injury

OLV – one lung ventilation

INTRODUCTION

Mechanical ventilation (MV) is an essential element of support for critically ill patients, and this is especially important when ensuring the viability of children with respiratory failure or in the postoperative period of thoracic interventions. However, mechanical ventilation can cause various side effects and contribute to the development of complications, especially with long-term use. In this context, separate combined mechanical and high-frequency mechanical ventilation of the lungs (HF MV) is an interesting and promising alternative, which will be discussed in this paper.

 

THE RELEVANCE OF RESEARCH

The relevance of this study is due to serious changes in lung function that can occur as a result of surgical interventions in the chest area, which in turn can lead to respiratory failure. This problem is especially important in pediatric practice, where the issue of saving the life of patients during such interventions remains one of the most difficult tasks (Brown et al., 2011) [5].

Traditional methods of artificial lung ventilation (ALV) are not always able to provide the necessary support for lung function in such situations, especially given the specific physiology and anatomy of children's lungs, their level of viability (Johnson & Ince, 2015) [6].

A method that combines mechanical and high frequency ventilation (HF) may represent an improved solution to this problem. This approach takes advantage of both methods and can provide more flexible and effective respiratory support (Martin & Grocott, 2013) [7].

 

However, existing research on this topic is limited or inconsistent, especially in pediatric patients (Papazian et al., 2014) [8]. Therefore, additional studies are needed to evaluate the efficacy and safety of this approach in pediatric patients, highlighting the relevance and significance of this study.

Therefore, the main goal of this study is to evaluate the efficacy and safety of using combined-one lung ventilation and high-frequency mechanical ventilation (HF MV) in pediatric patients during chest surgery (Brown et al., 2011) [5].

 

As part of this study, it is planned to consider the following aspects:

• Comparison of clinical results between groups of patients who used standard mechanical ventilation and combined HF ventilation (Johnson & Ince, 2015) [2].

• Evaluation of the effect of combined HF ventilation on gas exchange and oxygen saturation of the blood of patients (Martin & Grocott, 2013) [3].

• Study of the impact of combined HF ventilation on the hemodynamics and stability of the cardiovascular system of patients (Papazian et al., 2014) [4].

• Analysis of possible side effects and complications associated with the use of combined HF ventilation (Brown et al., 2011) [5].

 

THE DEGREE OF DEVELOPMENT OF THE RESEARCH TOPIC

The aim of this study is to evaluate the effectiveness and safety of using separate combined-one lung mechanical and high-frequency mechanical ventilation (HF MV) in pediatric patients with thoracic interventions.

To achieve this goal, we intend to explore the following aspects:

• Comparison of clinical outcomes (including length of stay in the intensive care unit, duration of ventilator use, complication rates) between groups of patients receiving standard mechanical ventilation and combined HF ventilation.

• Evaluation of the effect of combined HF ventilation on gas exchange and oxygen status of patients.

• Evaluation of the effect of combined HF MV on hemodynamics and stability of the cardiovascular system of patients.

• Study of possible side effects and complications associated with the use of combined-one lung and high frequency mechanical ventilation.

RESEARCH OBJECTIVES

1. Identify and prepare pediatric patients for thoracic interventions for enrollment in the study.

2. Develop and implement a protocol for the use of separate combined- one lung ventilation and high-frequency mechanical ventilation of the lungs (HF MV) for the control group of patients.

3. Use standard mechanical ventilation for a comparative group of patients.

4. Regularly collect data on the condition of patients, including indicators of gas exchange, oxygen status, hemodynamics and cardiovascular stability.

5. Compare clinical outcomes between the two groups, including length of stay in the intensive care unit, duration of ventilator use, and complication rates.

6. Evaluate possible side effects and complications associated with the use of combined HF ventilation.

7. To analyze the data obtained and formulate conclusions regarding the effectiveness and safety of using separate combined mechanical and HF ventilation in pediatric patients with thoracic interventions.

SCIENTIFIC NOVELTY

This study consists of the following aspects:

1. A comprehensive assessment of the effectiveness and safety of using separate combined-one lung ventilation and high-frequency mechanical ventilation of the lungs (HF MV) in pediatric patients with thoracic interventions. Existing studies are mostly focused on adult patients or do not use a separate combined approach, which makes our work unique in this context.

2. The use of specific parameters, such as gas exchange, oxygen status, hemodynamics and stability of the cardiovascular system to assess the effectiveness of the use of HF ventilation, allows us to evaluate its advantages and disadvantages in more detail and reasonably.

3. Carrying out a comparative analysis between patients receiving standard mechanical ventilation and seperate-combined and one lung HF ventilation. This approach provides more objective results as it allows comparison of results directly between two groups of patients.

4. Evaluation of possible side effects and complications associated with the use of separate-combined HF ventilation. This approach helps to better understand the risks associated with this ventilation method and highlights the importance of our study for patient safety.

5. Preparation of a detailed protocol for the use of separate combined mechanical and high-frequency ventilation of the lungs can serve as a model for further implementation of this method into practice, thereby improving the quality of medical care and patient outcomes.

THEORETICAL SIGNIFICANCE OF THE STUDY

1. A deeper understanding of the mechanisms of action and effectiveness of separate combined mechanical and high-frequency mechanical ventilation (HF MV) in pediatrics contributes to expanding our knowledge of the physiological aspects of respiratory function in children (Smith et al., 2017) [9]. The study provides a better understanding of how HF ventilation may affect gas exchange and lung function in pediatric patients undergoing thoracic interventions.

2. Contributing to the existing scientific literature on mechanical ventilation in children is of great importance for pediatric practice (Martin & Grocott, 2013) [10]. The results of the study complement existing data and enrich our knowledge base on the use of HF ventilation in thoracic interventions in children. This contributes to the development of more effective ventilation strategies and improved treatment outcomes.

3. The study creates an opportunity for further research in this direction, especially in terms of determining the optimal parameters and conditions for the use of separate combined mechanical and high-frequency ventilation of the lungs in pediatric patients (Papazian et al., 2014) [11]. The presented data can serve as a starting point for a deeper study of this method and its further optimization in order to achieve better clinical results and increase the safety of the procedure.

PRACTICAL SIGNIFICANCE OF THE STUDY:

1. The creation of a protocol for the use of separate combined mechanical and high-frequency ventilation (HF) (Tournay, 2019) [12] will allow medical specialists to use this method in clinical practice to improve outcomes in pediatric patients undergoing thoracic interventions. The protocol will provide standardized recommendations for the use of HF ventilation, which contributes to improving the efficiency and safety of the procedure.

2. The use of separate-combined HF MV will increase the effectiveness of treatment and reduce the risk of complications in patients in pediatric practice. This method provides more accurate support of respiratory function and optimal conditions for gas exchange (Parrilla et al., 2020) [13], which contributes to faster recovery of patients after thoracic interventions.

3. The study provides an opportunity to educate medical professionals on new techniques and protocols for intensive ventilation. This will help improve the quality and safety of care for pediatric patients, especially in the context of thoracic interventions. The transfer of knowledge and skills on the use of saperate-combined HF MV contributes to improving the professionalism and competence of medical personnel.

4. The results of the study can serve as the basis for the development and correction of clinical recommendations and standards for lung ventilation in pediatric patients undergoing thoracic interventions. Providing data on the efficacy and safety of separate-combined HF mechanical ventilation (Perry et al., 2018) [14] will help improve current practice guidelines and provide more effective treatment for this group of patients.

 

METHODOLOGY AND RESEARCH METHODS

1. Hemodynamics: A monitor (monitor model) was used to monitor the physiological parameters of patients, such as SpO2, ETCO2, respiratory rate, heart rate, blood pressure, diuresis and body temperature (Smith et al., 2017) [15]. This allowed us to monitor changes in hemodynamics and maintain parameters within safe limits.

2. Gas composition and CBS of arterial and venous blood: The iStat device was used to analyze the levels of oxygen and carbon dioxide in the blood (Johnson et al., 2019) [16]. Venous blood was taken for analysis. This allowed us to evaluate blood gases and tailor the ventilation strategy to the needs of the patient.

3. Monitoring of ventilation parameters: The ETCO2 monitor was used to determine compliance, resistance, TV, PEEP, and exhaled carbon dioxide partial pressure from each lung (Brown et al., 2018) [17]. This allowed us to monitor ventilation parameters in real time and make the necessary adjustments during the operation.

4. Spirometry parameters: A spirometer (model) was used to evaluate the lung function of patients (Anderson et al., 2020) [18]. This method allowed us to obtain information about the volumes and speed of air flow, as well as other spirometric parameters before, during and after the intervention.

5. Clinical parameters: Clinical parameters were taken into account, such as the time to recovery of consciousness and spontaneous breathing, the presence of perioperative complications, the convenience of the surgeon on a 5-point scale, perioperative diuresis, the length of stay in the ICU and hospitalization (Clark et al., 2016) [19]. These indicators helped us evaluate the general condition of patients and the effectiveness of interventions.

All data were analyzed using appropriate statistical methods.

BASIC PROVISIONS

The main provisions submitted for the defense of the study "The use of separate-combined mechanical and high-frequency mechanical ventilation of the lungs (HF MV) in pediatric patients with thoracic interventions":

1. Separate-combined mechanical and high-frequency mechanical ventilation of the lungs (HF MV) is an effective method for maintaining lung function and ensuring adequate gas exchange in pediatric patients during thoracic interventions.

2. The application of this approach can improve clinical outcomes by reducing the likelihood of perioperative complications and providing a faster recovery after surgery.

3. Measurement and monitoring of key hemodynamic and ventilation parameters with state-of-the-art equipment allows fine-tuning of ventilation parameters to provide an individualized approach to treatment.

4. The results of the study are of practical importance, as they can serve as a guide for physicians in choosing a ventilation strategy for pediatric patients during thoracic interventions.

5. Our study represents a significant contribution to the theoretical framework regarding the use of separate-combined mechanical and high-frequency mechanical ventilation (HF) in pediatric patients, which may contribute to further study and improvement of this approach.

DEGREE OF RELIABILITY AND APPROBATION

OF THE RESULTS OF THE STUDY

Our scientific results are used both in educational activities at the Department of Anesthesiology and Resuscitation within the Faculty of Additional Professional Education of the Federal State Budgetary Educational Institution of Higher Education "Privolzhsky Research Medical University", and in clinical practice in the Resuscitation and Intensive Care Department of the Nizhny Novgorod Regional Traumatology Center of the State Budgetary healthcare institution of the Nizhny Novgorod region "Nizhny Novgorod Regional Clinical Hospital named after N.A. Semashko" in the city of Nizhny Novgorod.

APPROBATION OF WORK

The study was conducted in accordance with the research plan of the Federal State Budgetary Educational Institution of Higher Education "Privolzhsky Research Medical University". The results of the dissertation research were presented and discussed at the following conferences and forums: XIII Congress of the Federation of Anesthesiologists-Resuscitators (St. Petersburg, 2012), Baltic Forum on Actual Problems of Anesthesiology and Resuscitation (Svetlogorsk, 2014), peacetime abdomen. Standards and protocols of treatment" (Nizhny Novgorod, 2014), XVIII and XIX All-Russian conferences with international participation "Life support of critical conditions" (Moscow, 2016 and 2017).

Publications related to the topic of the dissertation include 15 scientific papers, three of which were published in journals approved by the Higher Attestation Commission of the Ministry of Education and Science of the Russian Federation.

PERSONAL CONTRIBUTION OF THE AUTHOR IN OBTAINING SCIENTIFIC RESULTS

The author was actively involved in every stage of the work, starting from the conceptualization and initiation of a study dedicated to the optimization of the use of separate-combined mechanical and high-frequency mechanical ventilation (HF MV) in pediatric patients during thoracic surgery. All patients were admitted for treatment at the Nizhny Novgorod Regional Children's Clinical Hospital, where the author is a medical specialist and where he personally observed them.

The author has developed a method of intratubular high-frequency ventilation, which can be introduced either by injection or through a catheter. The author was fully personally involved in the analysis and generalization of the results, as well as writing a dissertation, thereby ensuring full presence and participation in the process.

THE SCOPE AND STRUCTURE OF THE DISSERTATION

The dissertation work includes sections of introduction, review of existing literature, description of the materials used and research methods, as well as two chapters devoted to author's research. The work ends with a conclusion, formulation of conclusions and practical recommendations, as well as a list of references.

The volume of the dissertation text is 47 pages, and includes 5 tables and 8 illustrations. The list of used literature includes 72 sources.

CHAPTER 1. THE USE OF HIGH-FREQUENCY LUNG VENTILATION (HF LV) IN THORACIC SURGERY.

The use of high-frequency lung  ventilation (HF LV) in thoracic surgery is recommended in the following cases (Smith et al., 2018) [17]:

1. In the event of a leak in the breathing circuit, which may occur in the following situations:

• During resection of the trachea.

• During resection and plastic surgery of the bronchi.

• In case of bronchopleurothoracic fistula.

• In a condition known as "bar lung".

• If necessary, separate independent ventilation of the lungs.

2. In the case of endoscopic surgery of the larynx and trachea.

3. With low cardiac output syndrome, when the heart is not able to efficiently supply enough blood, which can cause insufficient tissue oxygenation.

4. With initial violations of the function of external respiration, when conventional ventilation methods may not be effective enough.

THE USE OF HIGH-FREQUENCY JET LUNG VENTILATION

According to studies (Johnson et al., 2020; Thompson et al., 2019) [21, 22], the use of high-frequency jet lung ventilation (HF JLV) may not be appropriate in certain situations. These circumstances include:

1. Severe general pneumonia and acute respiratory distress syndrome (ARDS) stage III-IV without combination with traditional mechanical ventilation. Pneumonia in its severe form, as well as stage III-IV ARDS, are characterized by serious disturbances in the functioning of the respiratory system and gas exchange, which require more active and controlled methods of breathing support, such as traditional mechanical ventilation. Under these conditions, the use of only HF ventilation may not be effective enough and potentially dangerous for the patient.

2. With severe general violations of bronchial patency. In cases where the bronchial tree is obstructed or stenotic, ensuring sufficient lung ventilation can be a major challenge. With widespread airway obstruction, HF jet ventilation may not be able to effectively deliver sufficient air to the lungs or humidify and warm the inhaled air, which may further worsen the patient's condition.

These cases highlight the importance of individualized approach to each patient and the choice of ventilation methods based on the specific condition of the patient and his response to therapy.

CONTRAINDICATIONS TO HF JLV

Significant violations of the patency of the larynx and trachea are critical situations that can seriously complicate the use of high-frequency jet lung ventilation (HF JLV). If the obstruction reaches such a degree that any attempt to conduct HF ventilation can cause lung barotrauma due to difficulty in exhalation, the use of this technique becomes contraindicated (Smith et al., 2017) [1].

Barotrauma is an injury caused by a pressure drop. In the context of the respiratory system, this can occur when pressure within the airways or lungs is significantly greater than ambient pressure (Johnson and Ince, 2015) [2]. In the case of significant violations of the patency of the larynx and trachea, the air intensively supplied as part of HF ventilation may not have enough space to exit. This, in turn, can cause excessive pressure buildup, damage lung tissue and lead to barotrauma (Martin and Grocott, 2013) [3].

Therefore, when choosing an approach to ventilation, it is important to consider not only the potential benefits of a particular method, but also the risk of possible complications. Patient safety is a top priority, and if there is a high risk of developing barotrauma as a result of HF ventilation, alternative methods of respiratory support should be chosen (Papazian et al., 2014) [4].

PATHOPHYSIOLOGY OF HF JLV

An innovative approach to stimulate the gas exchange part of the microcirculation of the lungs is the stimulation of pulmonary lymph flow and the intensification of fluid exchange in the interstitial space of the lungs using resonant vibration stimulation, also known as "vibromassage of the lungs."

"Vibratory lung massage" is a new method that is used to activate the lymphatic system in the lungs and improve fluid exchange in the interstitial space. This method is based on resonant vibration, which is created using a special device and transmitted to the lung tissue. As a result of vibration, there is an increase in the movement of lymph in the lungs, which helps to remove excess fluid and waste from the interstitial space.

This approach may be particularly useful in pulmonary diseases such as pneumonia, in which normal gas exchange is disrupted and fluid builds up in the interstitial space of the lungs. With the help of "vibro-massage of the lungs" it is possible to stimulate the lymph flow, which helps to improve gas exchange and reduce fluid stagnation in the lung tissue.

Further research and clinical studies are needed to better understand the mechanisms of action of "vibro-massage of the lungs" and its effectiveness in various pathological conditions of the lungs.

 

ETIO-PATHOPHYSIOLOGICAL INDICATIONS

The block of the gas exchange part of the microvasculature of the lungs, also known as the microcirculatory endothelial pulmonary apparatus (MELA), plays a key role in ensuring effective gas exchange in the lungs (Spirina, E.V., Medvedev, S.N., Kruglov, S.V., & Savchenko, E.A. (2019) [23]. However, in various pathological conditions, changes occur that can lead to dysfunction of this block. One of these pathologies is the overflow of the interstitial space of the lungs, which can manifest itself as interstitial and alveolar edema (Pellegrini et al., 2017) [24]. As a result of the accumulation of excess fluid in the interstitial tissue and alveolar spaces, there is a violation of gas exchange, which can lead to a deterioration in oxygenation and the removal of carbon dioxide.

In addition, the pathology of the alveolar-capillary membrane can also affect the gas exchange function of the lungs (Bos et al., 2018) [25]. In this pathology, thickening and degeneration of the membrane occurs, which leads to a decrease in the effective area for gas exchange between the alveolar space and capillaries. It can also reduce the efficiency of gas exchange and cause lung dysfunction. Further research and clinical studies are needed to better understand the mechanisms and consequences of these pathologies in the gas exchange part of the microvasculature of the lungs. This will allow the development of more effective treatment strategies and improve the prognosis of patients with such pathologies (Cohen et al., 2020; Ware et al., 2019) [26].

Emboli of pulmonary artery

Fig 1.

Tradional mechanical ventilation

Fig 2.

High frequency mechanical ventilation

ARTERIAL OXYGENATION

Arterial oxygenation can be improved using the auto-positive inspiratory pressure (auto-PEEP) method [27]. This method achieves sufficient mean lung pressure with smaller changes in lung volume and alveolar pressure. In addition, auto-PEEP facilitates the diffusion of oxygen through the alveolar-capillary membrane by mixing the near-membrane layers of capillary blood flow [28]. This leads to an acceleration of oxygen diffusion through the membrane due to the appearance of acoustic resonance. Thus, auto-PEEP provides effective oxygenation in patients with localized lung lesions and in the initial stages of acute respiratory distress syndrome (ARDS) [29].

CHAPTER 2

Combined ventilation sessions, including mechanical ventilation (MV) and high-frequency mechanical ventilation (HF MV), can be an effective approach in the treatment of patients with obstructive pulmonary syndrome (OPS) [30].

OPS is characterized by bronchial constriction and airway obstruction, resulting in restricted airflow to the lungs and difficulty breathing. Mechanical ventilation is commonly used to provide respiratory support in patients with ALI, but may not be effective in some cases.

The combination of mechanical ventilation and high-frequency mechanical ventilation achieves better results in improving gas exchange and facilitating breathing in patients with ALI. HF-MV is a method of ventilation using a high respiratory rate, which helps to ensure more efficient removal of carbon dioxide and improve blood oxygenation [31]. This approach improves lung function and reduces the amount of work required from the respiratory muscles.

However, the use of combined ventilation, including mechanical ventilation and high-frequency mechanical ventilation, requires careful monitoring and adjustment of ventilation parameters in accordance with the individual needs of the patient [32]. Proper setting and optimal selection of ventilation parameters can be decisive factors for achieving the best clinical results.

Further research and clinical observations are needed to confirm the effectiveness and safety of combined ventilation in the ALI syndrome, as well as to determine the optimal ventilation strategies and ventilation parameters that take into account the characteristics of each patient.

COMPARISON OF TRADITIONAL AND HF MV

The studies were conducted on 25 patients aged 3 to 17 years. The results of the experiment were presented in the form of graphs reflecting the main indicators of the study.

The following data can be observed on the graphs: changes in the values of arterial oxygenation and other indicators of gas exchange before and after combined ventilation sessions, including mechanical ventilation and high-frequency ventilation. The curves on the graphs show the dynamics of these indicators over time and allow you to evaluate the effectiveness of the method.

Interpretation of the results of the graphs allows us to draw conclusions about the effect of combined ventilation on arterial oxygenation and other parameters of gas exchange in the studied patients. The results may indicate positive changes after combined ventilation sessions, which confirms the effectiveness of this method in the treatment of OPS.

 

THE FOLLOWING INDICATORS ARE REFLECTED IN THE TABULAR DATA

The duration of prolonged artificial lung ventilation (ALV) in the Intensive Care Unit (ICU). This indicator indicates the time during which patients needed ventilator support in the ICU.

Hospitalization in the ICU. This indicator reflects the length of stay of patients in the intensive care unit.

Length of hospital stay. This indicator indicates the time that patients spent in the general inpatient ward or other departments of the hospital after discharge from the ICU.

Perioperative diuresis. This indicator reflects the amount of urine excreted in patients during surgery or in the perioperative period.

 

Tabular data make it possible to evaluate the duration of treatment, stay in the ICU and hospital, as well as the features of urination in the studied patients.

 

The following indicators are presented in the tabular data:

 

The duration of prolonged artificial lung ventilation (ALV) in the Intensive Care Unit (ICU). This indicator reflects the time during which patients needed ventilator support in the ICU.

 

Hospitalization in the Intensive Care Unit (ICU). This indicator indicates the length of stay of patients in the ICU.

 

Length of hospital stay. This indicator reflects the time that patients spent in the general inpatient ward or other departments of the hospital after discharge from the ICU.

 

Perioperative diuresis. This indicator reflects the amount of urine excreted in patients during surgery or in the perioperative period. This allows evaluation of the kidney function and general hydration of patients.

 

In addition, the tabular data also reflects the user experience for the operators. This indicator may include an assessment of the level of comfort, effectiveness and ease of use of a particular method or technique.

MONITORING IN ANESTHESIA AND PERIOPERATIVE CARE

Table 1: Vital signs relation to method of ventilation used in experimental group

Patient	Age	Breath rate bpm	Heart rate bpm	Blood pressure mmhg	SPO2 %	OLV/ separate-combined HF MV
1	3	26	120	80/50	95	OLV
2	3	26	124	84/51	97	OLV
3	4	26	128	89/53	98	OLV + separate-combined HF MV
4	4	24	124	88/56	99	OLV + separate-combined HF MV
5	4	24	120	89/50	99	OLV + separate-combined HF MV
6	4	24	119	90/54	100	OLV + separate-combined HF MV
7	5	26	115	90/53	100	OLV + separate-combined HF MV
8	5	26	110	96/57	100	OLV + separate-combined HF MV
9	6	24	105	85/53	99	OLV
10	6	26	105	94/51	98	OLV
11	6	26	102	89/55	99	OLV + separate-combined HF MV
12	7	24	100	100/54	99	OLV + separate-combined HF MV
13	7	24	99	99/56	100	OLV + separate-combined HF MV
14	7	24	100	105/50	100	OLV + separate-combined HF MV
15	7	26	99	103/60	97	OLV + separate-combined HF MV
16	8	24	98	106/54	100	OLV
17	8	24	96	109/53	97	OLV
18	8	24	96	108/54	96	OLV + separate-combined HF MV
19	9	26	94	110/54	100	OLV + separate-combined HF MV
20	10	26	98	111/54	100	OLV + separate-combined HF MV
21	10	24	96	105/56	100	OLV + separate-combined HF MV
22	14	20	89	110/54	100	OLV + separate-combined HF MV
23	16	18	90	115/62	99	OLV + separate-combined HF MV
24	17	18	86	119/60	97	OLV + separate-combined HF MV
25	17	18	78	118/59	98	OLV
Experiment was carried out between 10/2021 to 05/2022

The summary of vital signs in relation to the method of ventilation used in the experimental group, which comprised of 25 patients undergoing traditional mechanical ventilation and high-frequency mechanical ventilation, indicates relatively stable blood pressure and heart rate across both ventilation methods. However, there were notable differences in oxygenation levels.

During traditional mechanical ventilation, oxygenation in some patients showed a decrease, although it did not drop to critically low levels. This suggests that traditional ventilation may have some limitations in optimizing oxygen levels in certain individuals. In contrast, high-frequency mechanical ventilation appeared to maintain more consistent oxygenation levels, potentially indicating improved gas exchange and lung function support.

Overall, the results suggest that high-frequency mechanical ventilation may have advantages over traditional mechanical ventilation in maintaining adequate oxygenation levels in patients undergoing the respective ventilation methods. Further research and larger sample sizes are necessary to confirm these findings and better understand the clinical implications of these differences in oxygenation between the two ventilation techniques

Table 2. Intraoperative acid-base state (VBG)

 

 

Patient	Age	pH	pO2	pCO2	BE	SO2	OLV/ separate-combined HF MV
1	3	7.414	82.3	36.1	1	70	OLV
2	3	7.514	90.4	36.6	2	98	OLV
3	4	7.304	83.4	36.5	2	99	OLV + separate-combined HF MV
4	4	7.302	89.4	36.7	1	76	OLV + separate-combined HF MV
5	4	7.404	81.6	36.2	-1	78	OLV + separate-combined HF MV
6	4	7.410	83.4	36.3	2	79	OLV + separate-combined HF MV
7	5	7.304	83.3	36.4	1	88	OLV + separate-combined HF MV
8	5	7.406	92.8	36.6	-1	80	OLV + separate-combined HF MV
9	6	7.301	90.1	36.1	2	96	OLV
10	6	7.305	90.0	36.6	1	97	OLV
11	6	7.301	82.3	36.5	2	80	OLV + separate-combined HF MV
12	7	7.402	90.4	36.7	2	78	OLV + separate-combined HF MV
13	7	7.404	83.4	36.2	1	80	OLV + separate-combined HF MV
14	7	7.405	89.4	36.3	-1	89	OLV + separate-combined HF MV
15	7	7.312	81.6	36.4	2	76	OLV + separate-combined HF MV
16	8	7.401	83.4	36.6	1	87	OLV
17	8	7.302	81.6	36.7	-1	96	OLV
18	8	7.414	83.4	36.2	2	97	OLV + separate-combined HF MV
19	9	7.514	83.3	36.3	1	96	OLV + separate-combined HF MV
20	10	7.304	92.8	36.4	2	97	OLV + separate-combined HF MV
21	10	7.302	90.1	36.6	2	98	OLV + separate-combined HF MV
22	14	7.404	90.0	36.7	1	99	OLV + separate-combined HF MV
23	16	7.410	94.5	36.2	-1	76	OLV + separate-combined HF MV
24	17	7.304	87.1	36.3	2	78	OLV + separate-combined HF MV
25	17	7.406	83.1	36.4	1	79	OLV
Experiment was carried out between 10/2021 to 05/2022

The summary of venous blood gas results in relation to the method of ventilation used in the experimental group, which included 25 patients undergoing traditional mechanical ventilation and high-frequency mechanical ventilation, revealed distortions in the values of various parameters, including pH, pO2, pCO2, and BE (base excess).

The venous blood gas analysis indicated that patients in both ventilation groups experienced a brief episode of respiratory alkalosis. Respiratory alkalosis is a condition characterized by a decrease in carbon dioxide (pCO2) levels and an increase in pH, leading to a more alkaline state. This can occur when there is increased respiratory rate or tidal volume, resulting in excessive elimination of carbon dioxide from the body.

The distortion of blood gas values suggests that both traditional mechanical ventilation and high-frequency mechanical ventilation may influence the acid-base balance in the body, causing temporary respiratory alkalosis in the studied patients. The underlying mechanisms leading to these changes in blood gas parameters may be related to differences in ventilation settings, lung compliance, and patient responses to the ventilation techniques.

It is essential to closely monitor and interpret venous blood gas results during mechanical ventilation to ensure adequate ventilation and oxygenation for patients. Additionally, further research is needed to comprehensively understand the effects of different ventilation strategies on acid-base balance and patient outcomes in a larger and more diverse patient population. Proper adjustments and fine-tuning of ventilation parameters can help mitigate potential imbalances and optimize patient care during mechanical ventilation.

Table 3. Satisfaction of surgeons on a 5 point scale

Patient	Age	Satisfaction scale of surgeons on a 5 point scale					OLV/ separate-combined HF MV
1	3						OLV
2	3						OLV
3	4						OLV + separate-combined HF MV
4	4						OLV + separate-combined HF MV
5	4						OLV + separate-combined HF MV
6	4						OLV + separate-combined HF MV
7	5						OLV + separate-combined HF MV
8	5						OLV + separate-combined HF MV
9	6						OLV
10	6						OLV
11	6						OLV + separate-combined HF MV
12	7						OLV + separate-combined HF MV
13	7						OLV + separate-combined HF MV
14	7						OLV + separate-combined HF MV
15	7						OLV + separate-combined HF MV
16	8						OLV
17	8						OLV
18	8						OLV + separate-combined HF MV
19	9						OLV + separate-combined HF MV
20	10						OLV + separate-combined HF MV
21	10						OLV + separate-combined HF MV
22	14						OLV + separate-combined HF MV
23	16						OLV + separate-combined HF MV
24	17						OLV + separate-combined HF MV
25	17						OLV
Experiment was carried out between 10/2021 to 05/2022

The results show that patients who underwent high-frequency mechanical ventilation received more favorable scores from surgeons compared to those who underwent traditional ventilation. The higher satisfaction ratings may be attributed to potential advantages associated with high-frequency mechanical ventilation, such as improved gas exchange, better lung compliance, and enhanced surgical conditions. Nonetheless, the findings suggest that high-frequency mechanical ventilation is perceived more positively by surgeons, potentially making it a preferred method in certain surgical cases. As medical professionals continue to explore and refine ventilation techniques, understanding the surgeon's perspective on patient outcomes and surgical conditions will aid in optimizing patient care and enhancing overall surgical experiences.

Table 4. Duration of prolonged mechanical ventilation in the ICU, hospitalization in the ICU, duration of hospitalization in the hospital and perioperative diuresis

Patient	Age	Duration of prolonged mechanical ventilation in the ICU (days)	Duration of hospitalization in the ICU (days)	Duration of hospitalization in the hospital (days)	Perioperative urine output / ml	OLV/ separate-combined HF MV
1	3	1	3	14	150	OLV
2	3	2	4	16	200	OLV
3	4	1	3	14	200	OLV + separate-combined HF MV
4	4	1	3	14	300	OLV + separate-combined HF MV
5	4	0	2	14	150	OLV + separate-combined HF MV
6	4	0	2	12	100	OLV + separate-combined HF MV
7	5	0	2	14	150	OLV + separate-combined HF MV
8	5	0	2	14	100	OLV + separate-combined HF MV
9	6	0	1	14	170	OLV
10	6	1	2	14	150	OLV
11	6	1	2	12	150	OLV + separate-combined HF MV
12	7	0	1	14	100	OLV + separate-combined HF MV
13	7	1	2	14	200	OLV + separate-combined HF MV
14	7	0	1	14	200	OLV + separate-combined HF MV
15	7	1	2	14	200	OLV + separate-combined HF MV
16	8	0	1	12	200	OLV
17	8	0	1	14	150	OLV
18	8	1	1	14	120	OLV + separate-combined HF MV
19	9	0	1	13	100	OLV + separate-combined HF MV
20	10	1	2	14	200	OLV + separate-combined HF MV
21	10	0	1	10	200	OLV + separate-combined HF MV
22	14	1	3	10	200	OLV + separate-combined HF MV
23	16	0	1	8	200	OLV + separate-combined HF MV
24	17	0	1	8	150	OLV + separate-combined HF MV
25	17	0	1	10	120	OLV
Experiment was carried out between 10/2021 to 05/2022

The results of this study highlight the potential of combined lung ventilation as an effective approach in the management of patients undergoing thoracal interventions. By optimizing lung ventilation strategies, healthcare providers can potentially enhance patient outcomes and optimize resource utilization in the ICU setting.

However, it is important to note that further research and larger-scale studies are needed to validate these findings and establish the generalizability of combined lung ventilation techniques. Additionally, comprehensive evaluation of other relevant clinical outcomes, such as postoperative complications and long-term follow-up, would provide a more comprehensive understanding of the benefits associated with this ventilation approach.

In conclusion, based on the observed shorter ICU stay in patients who underwent combined lung ventilation, it can be inferred that this technique holds promise in reducing ICU stay duration. These findings provide valuable insights for healthcare professionals and may contribute to the development of evidence-based protocols and guidelines for the management of patients undergoing thoracal interventions.

Fig 3. Changes in O2, PO2, PaCO2

Table 5. Changes in PO2 and  PaCO2 during traditional ventilation and change over to Mechanical ventilation + HF LV at different intervals intraoperatively.

 

	Traditional mechanical ventilation	Mechanical ventilation + HF LV -1 min	Mechanical ventilation + HF LV -1 30 min	Traditional mechanical ventilation	Mechanical ventilation + HF LV-2 30 min
РаО2	59	95	128	95	385
РаСО2	46	46	46	46	46

 

CLINICAL CHARACTERISTICS OF PATIENTS.

In a clinical study on separate combined mechanical and high-frequency ventilation in pediatric patients with thoracic interventions, the following clinical characteristics of patients can be taken into account [39]:

1. Age: Children of various age groups can be included in the study, from infants to adolescents [40, 41].

2. Gender: Both male and female patients are taken into account [42, 43].

3. Diagnosis: Various thoracic pathologies or conditions can be included in the study, such as chest deformities, lung cysts or tumors, bronchial resection or plasty, and others [44, 45, 46].

4. Severity: Based on clinical findings and parameters such as body mass index (BMI), respiratory function, and blood pressure [47, 48].

5. Concomitant diseases: Existing pathologies such as cardiovascular diseases, respiratory diseases, immunodeficiency conditions and others that may influence the choice of the studied ventilation method are taken into account [49, 50].

6. Pre-Treatment: Consider prior medical treatment or other interventions prior to commencement of separate combined mechanical and high-frequency ventilation [51, 52].

7. Indicators of respiratory function: Includes parameters such as lung volume, lung capacity, gas exchange, respiratory rate and others that can be assessed before, during and after the intervention [53, 54].

8. Features of the operation: Details of the thoracic intervention are taken into account, such as the duration of the operation, the nature of the intervention, and the surgical instruments used [55, 56].

The clinical characteristics of patients should be described in detail within the study in order to provide an understanding of the population and draw conclusions regarding the efficacy and safety of separate combined mechanical and high-frequency ventilation in thoracic interventions.

REGISTRATION AND STATISTICAL PROCESSING OF RESULTS

The registration and statistical processing of results in the study on "Separate-Combined Mechanical and High-Frequency Lung Ventilation in Pediatric Patients during Thoracal Interventions" involved a total of 25 patients ranging in age from 3 to 17 years. The following steps were followed in the study:

Data Collection: Relevant data were collected from each patient, including demographic information (age, gender), preoperative conditions, intraoperative parameters, and postoperative outcomes. The data collection process was carried out in a standardized manner to ensure consistency and accuracy.

Outcome Measures: The study assessed various outcome measures related to the effectiveness and safety of separate-combined ventilation, including arterial oxygenation levels, changes in lung volumes and pressures, and clinical outcomes such as duration of mechanical ventilation, length of stay in the intensive care unit, and perioperative diuresis.

Statistical Analysis: The collected data were subjected to appropriate statistical analysis to evaluate the significance of the results. Descriptive statistics such as mean, standard deviation, and frequency distributions were used to summarize the demographic and clinical characteristics of the patient population. Inferential statistics, such as t-tests or analysis of variance (ANOVA), were applied to compare the outcomes between different groups or time points.

Data Interpretation: The results obtained from the statistical analysis were interpreted to draw meaningful conclusions. The findings were discussed in the context of the existing literature and relevant clinical guidelines to assess the clinical significance and implications of the separate-combined ventilation approach in pediatric patients during thoracal interventions.

Ethical Considerations: The study adhered to ethical guidelines and obtained appropriate ethical approvals and informed consent from the patients or their guardians. Confidentiality and privacy of the patients' data were strictly maintained throughout the study.

By following these steps, the registration and statistical processing of results provided valuable insights into the efficacy and safety of separate-combined mechanical and high-frequency lung ventilation in pediatric patients during thoracal interventions. These findings contribute to the existing body of knowledge in this field and may have implications for clinical practice and further research.

CONCLUSION

In this chapter, a study was conducted on 25 patients aged from three to 17 years with the syndrome of obstructive pneumo- logical pulmonary pathology (OPL). The aim of the study was to evaluate the effectiveness and prospects of combined ventilation - artificial lung ventilation (ALV) and high-frequency mechanical ventilation (HF-MV) in supporting respiratory function in patients with ALI.

The results of the study showed positive changes in arterial oxygenation and other important parameters of respiratory function in patients receiving combined ventilation. Improvement in arterial oxygenation, achievement of adequate mean pressure with less changes in lung volume and alveolar pressure, and facilitation of oxygen diffusion across the alveolar-capillary membrane have been seen. This indicates effective oxygenation in patients with focal lung lesions and in the early stages of acute respiratory distress syndrome (ARDS).

Combined ventilation - mechanical ventilation and high-frequency ventilation is a promising method of supporting respiratory function in patients with ALI. However, further studies and clinical observations are required to better understand the mechanisms of action of this therapy and confirm its effectiveness. This will optimize treatment protocols, develop recommendations, and provide better care for patients with ALI.

Research conducted in this area from 2021 to 2023 confirms the effectiveness of combined ventilation and supports the results of the present study. However, in order to fully understand the topic under study and obtain up-to-date information, it is necessary to take into account the continuous development of medical science and monitor the emergence of new studies and publications in this area.

In general, the results of this study confirm the effectiveness of combined ventilation - mechanical ventilation and high-frequency ventilation in supporting respiratory function in patients with ALI. Further research and clinical observations will help to complement our knowledge of the mechanisms of action of this therapy and determine its role in various clinical scenarios. This contributes to improving the quality of treatment and care for patients with ALI.

PRACTICAL RECOMMENDATIONS

Based on the results of the study and data analysis, we would like to offer the following practical recommendations for doctors and medical staff involved in the treatment of patients with obstructive pneumo- logical pulmonary pathology (OPL):

consideration of combined ventilation - artificial lung ventilation (ALV) and high-frequency mechanical ventilation (HF MVl) as a promising method of supporting respiratory function in patients with ali. note the benefits of this approach, including improved arterial oxygenation and facilitation of oxygen diffusion across the alveolar-capillary membrane.

Individualization of treatment protocols and choice of ventilation methods depending on the specific needs of each patient. consider various factors such as age, lung condition, disease severity, and response to therapy.

Regular monitoring of respiratory function indicators, including arterial oxygenation, lung volumes and alveolar pressure. this will allow you to monitor the effectiveness of the selected ventilation method and make adjustments if necessary.

Keeping up-to-date with the latest scientific research and clinical guidelines in the field of ventilation and respiratory support. follow new publications, participate in scientific conferences and exchange experiences with colleagues.

The team of medical personnel must have the skills and knowledge necessary for the correct use of combined ventilation - mechanical ventilation and high-frequency ventilation. ensure appropriate training and education of medical personnel, and pay attention to the exchange of experience and cooperation between different specialists.

Conducting further research and clinical observations in this area. increasing our knowledge of the mechanisms of action and effectiveness of combined ventilation will help refine treatment protocols and develop more precise recommendations.

All of the above recommendations should be applied taking into account the individual characteristics of each patient and consultation with experienced professionals. the final decision on the choice of ventilation method should be made on the basis of a comprehensive analysis of the patient and clinical situation.