Effect of transnasal humidified rapid-insufflation ventilatory exchange on the incidence of hypoxemia in sedated gastroscopy in children: a randomised controlled trial

Abstract

Background

Transnasal humidified rapid-insufflation ventilatory exchange is a novel ventilation modality which can provide very high flow (up to 70 l/min) heated and humidified gas with adjustable temperatures (31–37 °C) and oxygen concentrations (21–100%). However its application in sedated gastroscopy in children has received little attention.

Objective

To observe transnasal humidified rapid-insufflation ventilatory exchange in sedated gastroscopy in children and its effect on the incidence of hypoxemia.

Design

A prospective randomized clinical trial.

Setting

Endoscopy Center in Shenzhen Children’s Hospital.

Patients

120 children (ASA grade I–II), aged 6–12 years with a body mass index of 18–25 kg m-2, who underwent sedated gastroscopy at Shenzhen Children’s Hospital between June 2022 and November 2022.

Interventions

The participants were randomly assigned in a 1:1 ratio to receive transnasal humidified rapid-insufflation ventilatory exchange or nasal cannula oxygen therapy.

Main outcome measures

The primary outcome was hypoxemia incidence. The secondary outcomes included the lowest oxygen saturation index, duration of hypoxemia, incidence of adverse respiratory conditions, intervention rate, and endoscopist satisfaction.

Results

Five children (8.3%) in thetransnasal humidified rapid-insufflation ventilatory exchange group had hypoxemia compared with 17 (28.3%) in the nasal cannula group, with a significant difference (P<0.01). The lowest oxygen saturation index in two groups shows no significant difference [98 (95, 99) vs. 98 (90, 99), P=0.087]. However compared with the nasal cannula group, the duration of hypoxaemia was significantly shorter (9.00 ± 1.73 s vs. 13.18 ± 3.49 s, 95% CI -6.63 to -1.72; P<0.01), the intervention rate was significantly lower (n=7, 11% vs. n=18, 30%; P<0.05), the incidence of adverse breathing complications was significantly lower (n=8, 13.3% vs. n=18, 30%; P<0.05), and the satisfaction of endoscopists was significantly higher (88.3% vs. 68.3%, P<0.05) in the transnasal humidified rapid-insufflation ventilatory exchange group.

Conclusion

Transnasal humidified rapid-insufflation ventilatory exchange can promote oxygenation reducing the incidence of hypoxemia in sedated gastroscopy in children.

Trial registration

ChiCTR2200060799.

Key points

- THRIVE can reduce the work of breathing and improve oxygenation in children.

- THRIVE can provide positive respiratory and continuous positive airway pressure, thereby promoting end-respiratory alveolar dilation.

- THRIVE ensures oxygenation during short duration paediatric gastroscopy.

Background

With the advancement of medical technology and the increase of patients’ demand for diagnosis and treatment, painless gastroscopy came into being with low dose general anesthesia, which is a crucial means for the diagnosis and treatment of digestive tract diseases, and the gold standard for the diagnosis of upper gastrointestinal diseases. [1] For children, anxiety and nervousness are likely to arise during the gastroscopy and assessment, which may result in long-term adverse behavioral changes. Sedated gastroscopy can effectively improve the cooperation and reduce the tension both in children and their parents. [2] However, hypoxemia is the most common complication of painless gastroscopy, [3] the younger the child, the greater the possibility of developing hypoxemia, and there are fewer efficient ways to cope [4].

Transnasal humidified rapid insufflation ventilatory exchange (THRIVE) is a new non-invasive respiratory support technology, which is defined as high-flow NC therapy (HFNC) that was originally used for continuous positive airway pressure (CPAP). THRIVE can transmit heated and humidified high-flow gas through a nasal cannula (NC), which not only achieves positive pressure ventilation but also effectively reduces physiological ineffective cavities, generates positive end-respiratory pressure, promotes end-respiratory alveolar dilation. [5–7] It can be used in respiratory intensive care units to treat premature infants and children with lung diseases such as respiratory distress syndrome, tracheobronchitis, and respiratory failure [8, 9]. Other studies have shown that THRIVE is safe and reliable when used in airway manipulation gastroscopy, as it can preserve spontaneous breathing, effectively ensure intraoperative oxygenation and reduces the incidence of perioperative hypoxemia [10, 11].

In recent years, many researchers have applied THRIVE to sedated gastroscopy in adult and elderly patients, and the results have shown that THRIVE can significantly improve oxygenation and reduce the incidence of hypoxemia during the gastroscopy [12, 13]. However, there are few such studies in children.

The main objective of this study was to observe transnasal humidified rapid-insufflation ventilatory exchange in sedated gastroscopy in children and its effect on the incidence of hypoxemia, the lowest oxygen saturation index, duration of hypoxemia, incidence of adverse respiratory conditions, intervention rate, and endoscopist satisfaction compared with nasal cannula oxygen therapy.

Methods

Study design and participants

This prospective, single-center, randomized, parallel-group clinical trial was approved by the Ethics Committee of Shenzhen Children’s Hospital (reference number: 2021087,09/09/2021 Chairperson Xin Qi). and registered in the Chinese Clinical Trials Registry (http://www.chictr.org.cn; ChiCTR2200060799,12/06/2022). The trial was conducted in the endoscopy suite of Shenzhen Children’s Hospital (Shenzhen, China) between June 2022 and November 2022 and adhered to the Good Clinical Practice guidelines and principles of the Declaration of Helsinki. All the children and their parents signed an informed consent form before enrollment. A total of 124 children who underwent sedated gastroscopy at Shenzhen Children’s Hospital were selected regardless of sex (age range 6–12 years, BMI range 18–25 kg m⁻², and ASA grade I–II). The exclusion criteria were as follows: allergy to anesthetics such as propofol and remifentanil; deviated nasal septum or other nasal anatomical abnormalities; obstructive sleep apnea syndrome; refusal of parents or guardians to participate in the study; Simultaneously, since hemoglobin content is one of the numerous factors influencing SpO₂, we eliminated children with hematologic illnesses and those with hemoglobin levels above normal to prevent the impact of these conditions on the experimental outcomes. [14] All children underwent laboratory tests, such as ECG, chest radiography, and routine blood tests, before painless gastroscopy and were evaluated by the same senior anesthesiologist.

Randomisation and blinding

An anesthesiologist who did not participate in the study used SPSS (version 21.0; IBM, Armonk, NY) to design a random number table. After obtaining informed written consent, all participants were randomly assigned in a 1:1 ratio to the THRIVE or NC group according to this table. Then the same anesthesiologist recorded the child’s name, group, and random number in an envelope. The child’s name and hospitalization number are written on the envelope. We prepared two sets of envelope. The endoscopic nurse received one copy, which she opened throughout the trial to ascertain the child’s oxygen delivery method. Another copy was saved. Because compared to the NC group, the THRIVE group received an additional external oxygen heating and humidification device, which means the data collectors, handlers, and endoscopists were not blinded to the experiment.

Study interventions

All children fasted for 8 h and ceased drinking for 2 h before gastroscopy. The upper extremity venous access was opened, and daclonine glue (Yangzijiang Pharmaceutical Co., Nanjing, China) was applied before entering the gastroscopy room. After admission, ECG, non-invasive blood pressure, pulse oximetry, and depth of anesthesia (Narcotrend; MonitorTechnik, Bad Bramstedt, Germany) were monitored. Propofol (2 mg kg⁻¹) and remifentanil (0.4 µg kg⁻¹) were used for anesthesia induction. Both are given as intravenous boluses. Narcotrend was used to monitor the depth of anesthesia. When the child became unconscious, the nurse at the endoscopy center provided one of the two oxygen therapy interventions. There is some debate about whether or not to pre-oxygenate children under anesthesia, and some studies have found no statistically significant difference in the amount of respiratory intervention required intraoperatively between pre-oxygenated and conventionally oxygenated children. While preoxygenation is less likely to cause hypoxia than it would be without preoperative oxygen supply, it is frequently linked to an increased incidence of apnea, the need for assisted ventilation, and other problems. [15–18] Considering a variety of considerations, including the briefness of our examinations and the child’s participation with pre-oxygenation, we did not pre-oxygenate the children in this trial. To protect the child’s safety during the procedure, we have thus conducted more thorough vital sign monitoring. The THRIVE group was treated with a THRIVE therapy device (Guangzhou Cetacean Medical Technology Co., Guangzhou, China) with an oxygen flow rate of 1 l kg⁻¹min⁻¹ (up to 30 l min⁻¹), oxygen concentration of 40%, and temperature of 34 °C. The oxygen therapy method in the NC oxygen therapy group was based on traditional NC with an oxygen flow rate of 4–5 l min⁻¹, ensuring the oxygen concentration was the same in both groups (oxygen concentration in group N: FiO₂ = 0.21 + 0.04*oxygen flow rate). When the depth of anesthesia reached Narcotrend stage D₀–D₁ (Narcotrend value 47–64), the child was placed in the left decubitus position, and gastroscopy was started. All patients remained on spontaneous ventilation throughout the procedure.

The Observer Assessment of Alertness/Sedation (OAA/S) rating was maintained at 0. If the child had a Narcotrend value > 64 or choking and physical movement during the procedure, propofol (1 mg kg⁻¹) was immediately administered. Attention was paid to changes in vital signs and breathing conditions during the gastroscopy. If the oxygen saturation (SpO₂) was ≤ 95%, the oxygen inhalation concentration or flow rate increased in the THRIVE and NC groups, respectively. If the inspired fraction of oxygen (FiO₂) in the THRIVE group was increased to 100% or the oxygen flow rate in group N was increased to 10 l min⁻¹, SpO₂ remained ≤ 92%, and/or adverse breathing conditions such as breath-holding, three concave signs, chest and abdominal paradoxical movements, snoring, and stridor, other interventions such as jaw- and mask-assisted ventilation were provided and tracheal intubation with mechanical ventilation was performed if severe hypoxemia could not be corrected. When we observe the child experiencing apnea without desaturation, we will immediately attempt to determine the cause of the apnea. Firstly, if the source of the apnea is anesthetic medications which commonly cause respiratory depression in clinical practice, we will closely monitor the patient to observe whether the patient’s breathing recovers quickly. If the oxygen saturation falls during the observation, we will take action, such as raising the oxygen concentration. Secondly, regardless of whether there is a decrease in oxygen saturation, we will offer respiratory support, such as jaw lifting, in cases of apnea brought on by respiratory obstruction.

Study outcome assessments

Respiratory rate (RR), heart rate (HR), mean arterial pressure (MAP), and SpO₂ were recorded before anesthesia induction (T₀) and at 1, 3, and 5 min (T₁, T₂, and T₃, respectively) after the start of gastroscopy. The incidence of poor breathing (breath-holding, three-reveal sign, chest and abdominal paradoxical movements, snoring, stridor, etc.) During diagnosis and treatment, incidence of minimum SpO₂, hypoxemia (SpO₂ ≤ 92%), duration of hypoxemia (the time required for SpO₂ to recover from the lowest value to the value before anesthesia induction in the presence of hypoxemia), use of hypoxic interventions, total dosage of propofol, and time of diagnosis and treatment were recorded. These include the minimum SpO₂, the incidence of hypoxemia, the duration of hypoxemia, and other indicators that are monitored during the entire surgical procedure. We will also accurately record any unique circumstances, such as hypoxemia, that occur outside of the non-recording time (T₀, T₁, T₂, T₃). After the end of gastroscopy, the endoscopists were asked to report their subjective satisfaction with the diagnosis and treatment process as follows: satisfied (successful in one visit, the child had no physical movement during gastroscopy, with or without a decrease in SpO₂, no anesthesiologist intervention was required, no need to stop the operation), generally satisfied (if one advanced examination was successful, the child experienced physical movement and SpO₂ decline during gastroscopy, and the anesthesiologist was required to intervene, but there was no need to withdraw the lens), or dissatisfied (the child had frequent intraoperative physical movements, with a decrease in SpO₂, and needed mask ventilation and other interventions after retreating). Children were assessed within 24 h of the end of gastroscopy, and the incidence of adverse reactions such as pneumothorax, abdominal distension, nausea, vomiting, and nasal discomfort in both groups was recorded. The same gastroscopic surgeon performed all procedures.

Statistical analysis

The sample size for this study was calculated based on the results of a preliminary experiment. The mean minimum SpO₂ in the THRIVE and NC groups was 98% and 88% (respectively), the standard deviation was 10%, the two-tailed significance level (α) was 0.05, and the test efficacy was 0.8 (β = 0.2). The sample size was calculated using PASS 15.0 (NCSS, Kaysville, UT) as 112 cases. Considering that some children would not be adequately prepared for the gastrointestinal tract or may withdraw from the study, the dropout rate was calculated as 0.1, resulting in a final sample size of 124. Statistical analyses were performed using SPSS (version 21.0; IBM). Normally distributed measures were expressed as mean ± standard deviation, and non-normally distributed measures were expressed as median (interquartile range). Normally distributed data with homogeneity of variance were assessed using the t-test; otherwise, the rank-sum test was used for intergroup comparisons. Count data are expressed as frequency (percentage) and compared using the chi-squared test. Differences were considered statistically significant at P < 0.05.

Results

The flow diagram of this study is shown in Fig. 1. From June 2022 to November 2022, a total of 124 children were initially included in this study, of which two children cancelled gastroscopy due to fever and two declined to participate. Ultimately, 120 patients were included in this study. There were 60 cases in each group. There were no significant differences in sex, BMI, admission SpO₂, or ASA grade between the two groups (all P > 0.05; Table 1).

Fig. 1.

Flow diagram of the eligibility, randomisation, and follow-up of participants

Table 1.

Comparison of the general condition of the two groups

	THRIVE (n = 60)	NC (n = 60)	P-value
Sex, male/female (n)	30/30	29/31	0.855
Age (years)	8.93 ± 1.89	8.73 ± 1.99	0.574
BMI (kg m−2)	20.67 ± 1.64	20.15 ± 1.79	0.103
Baseline SpO2 (%)	99(99,100)	99(99,100)	0.639
ASA grade (I/II)	60/0	60/0

Data are presented as mean ± standard deviation (SD) for age and BMI and median [IQR] for Baseline SpO₂. THRIVE, transnasal humidified rapid-insufflation ventilatory exchange; NC, nasal cannula; SpO₂, oxygen saturation

Compared to T₀, HR, MAP, and RR were significantly reduced (P < 0.05) at T₁, T₂, and T₃ after the start of gastroscopy in the NC group, and SpO₂ at T₂ was significantly reduced in the NC group compared to T₀ and T₁ (P < 0.05). HR, MAP, RR, and SpO₂ at T₁, MAP, and RR at T₂ were significantly reduced in the THRIVE group compared with T₀ (P < 0.05), and RR and SpO₂ at T₃ were significantly higher than those at T₁ and T₂ (P < 0.05). Compared with the NC group, SpO₂ at T₂ and RR at T₃ in the THRIVE group were significantly increased (P < 0.05 and < 0.01, respectively) (Table 2).

Table 2.

Comparison of HR, MAP, RR, and SpO₂ at different timepoints in the two groups

Time	HR (bpm)	MAP (mmHg)	RR (breaths min−1)	SpO2 (%)
T0
THRIVE	89 ± 14	69.05 ± 4.88	20 ± 4	100 (99, 100)
NC	89 ± 13	69.25 ± 3.81	20 ± 3	100 (99, 100)
T1
THRIVE	83 ± 12a	63.47 ± 4.60a	16 ± 4a	99 (98, 100)a*
NC	82 ± 11a	63.85 ± 4.53a	17 ± 4a	100 (99, 100)
T2
THRIVE	87 ± 15	62.25 ± 4.94a	17 ± 4a	100 (99, 100)b*
NC	84 ± 16a	62.07 ± 3.74a	16 ± 4a	99 (97, 100)ab
T3
THRIVE	87 ± 15	62.25 ± 5.29a	18.73 ± 4.03bc*	100 (100, 100)bc
NC	84 ± 13a	62.90 ± 4.66a	16.42 ± 4.12a	100 (99, 100)c

Data are presented as mean ± standard deviation (SD) for HR, MAP and RR and median [IQR] for SpO₂. ^a P<0.05, compared to T₀; ^b P<0.05, compared to T₁; ^c P<0.05, compared to T₂; * P<0.05, compared to NC group. THRIVE, transnasal humidified rapid-insufflation ventilatory exchange; NC, nasal cannula; HR, heart rate; MAP, mean arterial pressure; RR, respiratory rate; SpO₂, oxygen saturation

There were five patients (8.3%) in the THRIVE group and 17 (28.3%) in the NC group (P < 0.01) had hypoxemia. The duration of hypoxemia was significantly shorter in the THRIVE group compared to the NC group (9.00 ± 1.73 s vs. 13.18 ± 3.49 s, 95% CI −6.63 to −1.720, P < 0.01). The incidence of adverse breathing complications (n = 8, 13.3% vs. n = 18, 30%; P < 0.05) and the rate of intervention (n = 7, 11% vs. n = 18, 30%; P < 0.05) were significantly lower in the THRIVE group than in the NC group (Table 3).

Table 3.

Comparison of respiratory-related adverse events and interventions in the two groups

	THRIVE (n = 60)	NC (n = 60)	P-value
hypoxemia, n (%)	5 (8.3)	17 (28.3)	0.005
Duration of hypoxemia (s)	9.00 ± 1.73	13.18 ± 3.49	0.003
Lowest SpO2 (%)	98 (95, 99)	97.5 (89.7, 99)	0.087
Poor breathing, n (%)	8 (13.3)	18 (30)	0.027
Interventions, n (%)	7 (11.7)	18 (30)	0.013

Data are presented as mean ± SD for duration of hypoxemia, median [IQR] for lowest SpO₂ and n(%) for hypoxemia, Poor breathing and Interventions. hypoxemia: SpO₂ ≤ 92%; duration of hypoxemia: time required for SpO₂ to recover from lowest to pre-anesthesia induction in hypoxemia; adverse breathing conditions including breath holding, three concave signs, paradoxical chest and abdominal movements, snoring, and stridor; interventions including jaw support, mask ventilation, and mechanical ventilation for endotracheal intubation. THRIVE, transnasal humidified rapid insufflation ventilatory exchange; NC, nasal cannula; SpO₂, oxygen saturation

The baseline SpO₂ and lowest SpO₂values are shown in Fig. 2. There was no statistically significant difference between the two groups in the lowest SpO₂, but the lowest SpO₂ interquartile ranges in the THRIVE group ranged from 95 to 100%, and from 90 to 100% in the NC group.

Fig. 2.

The situation about the baseline SpO₂and the lowest SpO₂in two groups. (a) Box plot of baseline oxygen saturation (SpO₂) in the two groups (P=0.639). (b) Box plot of lowest SpO₂ in the two groups (P=0.087). THRIVE, transnasal humidified rapid-insufflation ventilatory exchange; NC, nasal cannula

There were no significant differences in gastroscopy time, propofol dosage, or awakening time between the two groups. One child in each group complained of nasal discomfort, which disappeared after 2 min. The satisfaction of endoscopists in the THRIVE group was significantly higher than that in the NC group (P < 0.05) (Table 4).

Table 4.

Comparison of gastroscopy-related indicators between the two groups

	THRIVE (n = 60)	NC (n = 60)	P-value
Duration (min)	7.87 ± 1.55	7.58 ± 2.30	0.432
Dose of propofol (mg)	106.75 ± 30.67	101.42 ± 30.10	0.338
Wake-up time (min)	4.25 ± 2.26	4.70 ± 1.97	0.247
Adverse reactions, n (%)	1 (1.7)	1 (1.7)
Endoscopist satisfaction (Satisfied/Fair/Unsatisfied), n (%)	53 (88.3)/ 7 (11.7)/ 0 (0)	41 (68.3)/ 17 (28.3)/ 2 (3.3)	0.021

Data are presented as mean ± SD for duration, dose of propofol and wake-up time and n (%) for adverse reactions and endoscopist satisfaction. Awakening time: the time between the end of gastroscopy and the Steward awakening score ≥ 4 points; adverse effects including pneumothorax, bloating, nausea, vomiting, nasal discomfort; endoscopist satisfaction: satisfaction (successful in one advance examination, no physical movement during gastroscopy, with or without SpO₂ decrease, no anesthesiologist intervention, no need to stop the operation), generally satisfied, (fair; one advance examination is successful, the child has physical movement and SpO₂ decline during gastroscopy, the anesthesiologist is required to intervene, no need to withdraw the lens), unsatisfied (frequent intraoperative physical movements, decreased SpO₂, need to be treated with mask ventilation and other interventions after lens withdrawal). THRIVE, transnasal humidified rapid insufflation ventilatory exchange; NC, nasal cannula; SpO₂, oxygen saturation

Discussion

Our findings suggest that THRIVE can be employed as an upper-position substitute for nasal cannula oxygen inhalation during painless pediatric gastroscopy.

In this study, there was no significant difference in the basic conditions (including sex, age, BMI, Baseline SpO₂ and ASA grade) between the two groups. As shown in Table 1.

In order to determine if the two forms of oxygen administration had an impact on children’s hemodynamics, our study used HR and MAP as hemodynamic monitoring metrics. For us to consider values that vary by more than 20% of the baseline value as clinically relevant, we use this criterion in conjunction with research conducted by Kaszyński et al. [19] There were statistically significant differences in HR, MAP and RR between the two groups over certain time periods, but were not clinically significant. This implies that there is minimal hemodynamic impact from the two oxygen delivery methods. As shown in Table 2.

In order to ensure the safety of the children and reduce unnecessary trauma, the pulse oximetry index (SpO₂) was used instead of arterial partial pressure of oxygen (PaO₂) as an indicator to measure hypoxemia. For the occurrence of hypoxemia, Kelly and Nay have utilized SpO₂ ≤ 92% as a reference. [20, 21] In this study, considering the specific conditions of the research (the low oxygen reserve and high oxygen consumption in children) and experiments of the above scholars, SpO₂ ≤ 92% was used as the reference index for hypoxemia.

In the past, some researchers found that THRIVE can cause complications such as abdominal distension, pneumothorax, and pneumomediastinum in children, which are considered to be related to the long duration of THRIVE and the higher flow setting [22, 23].

To ensure the safety of all children, the flow of our study was based on the application experience of THRIVE in children in intensive care units, in which the optimal oxygen flow was 2 l kg⁻¹ min⁻¹. In addition, we included the recommendations of Humphreys et al., where children weighing between 0 and 15 kg, 15–30 kg, 30–50 kg, or > 50 kg have an optimal oxygen flow of 2 l kg⁻¹ min⁻¹, 35 l min⁻¹, 40 l min⁻¹, or 50 l min⁻¹, respectively. [24] And considered the actual situation of our pre-experiment. The relevant parameters were set as follows: oxygen flow, 1 l kg⁻¹min⁻¹ (maximum, 30 l min⁻¹); FiO₂, 40%; and temperature, 34 °C. The FiO₂ in the standard nasal cannula group is variable and dependent on the patient’s inspiratory flow and breathing pattern. Thus, in order to reduce the variation in oxygen concentration caused by the oxygen supply equipment, we attempt to make the two initial oxygen concentration parameters consistent.

The incidence of hypoxemia was considerably lower in the THRIVE group than in the NC group, as Table 3 illustrates. Five children (8.3%) in the THRIVE group experienced hypoxemia, compared to seventeen children (28.3%) in the NC group. This difference was statistically significant. The incidence of poor respiratory conditions and respiratory support due to hypoxemia was lower in the THRIVE group than in the NC group, which is consistent with the findings of Zhang et al.‘s study on the use of THRIVE in painless gastroscopy in the elderly [13].

According to Laffin et al.‘s research, we discovered that for certain unique patients, including those who are obese, the indication of the duration of hypoxemia has some observational importance [25]. For some people, prolonged hypoxemia may result in permanent harm. In order to give a specific reference for the oxygen supply strategy of gastroscopy in exceptional children with impaired cardiopulmonary function, we included this indicator in our study as well. The THRIVE group considerably shortened the duration of hypoxemia, although we did not find a statistically significant difference between the two groups in the lowest oxygen saturation index under this criterion. As shown in Table 3. The findings indicate that THRIVE has certain advantages to NC in terms of enhancing the hypoxic condition of children undergoing painless gastroscopy. Given this feature of THRIVE, in which periods of apnea may occur and in which spontaneous ventilation is desired, such as computerized tomography or magnetic resonance imaging, THRIVE may also be chosen as an oxygen delivery method.

As shown in Table 4, there was no significant difference in the gastroscopy time, propofol dosage and awakening time between the two groups. However, the time of gastroscopy in this study is no more than 10 min, and whether long-term endoscopic is equally safe still needs to be verified by a large number of multi-center clinical randomized trials.

One patient in each group developed nasal discomfort after treatment, and both improved after 2 min. There was no other discomfort within 24 h, indicating that THRIVE is safe and reliable as a method of oxygen therapy for painless gastroscopy in children with 1 l kg⁻¹min⁻¹ oxygen flow.

Referring to the Pourabbas et al. study, we added endoscopist satisfaction as an indicator in the data collection because it may have an impact on the endoscopic procedure’s detection rate. [26, 27] THRIVE may assist increase endoscopic efficiency, since Table 4 demonstrates that endoscopist satisfaction was higher in the THRIVE group than in the NC group.

Our study was a randomized controlled clinical trial, and the limitations of this study are as follows. First, the sample size of this study was the minimum sample size calculated, and children with obstructive sleep apnoea syndrome and obesity were excluded. The relevant application effect requires a larger sample size and multicenter clinical trials. Second, because it was difficult for children to cooperate with pre-oxygenation, we chose to administer a different oxygen therapy when the eyelash reflex disappeared after anesthesia induction, which resulted in THRIVE losing its advantage in improving oxygen reserve in pre-oxygenation[24]. This may be one of the reasons for the five cases of hypoxemia in the THRIVE group and the absence of a significant difference in the lowest SpO₂ between groups. However, even in the absence of preoxygenation, THRIVE was superior to NC therapy in terms of reducing the incidence of hypoxemia, shortening the duration of hypoxemia, and improving oxygenation. Third, Hermez et al. confirmed that THRIVE reduced the accumulation of carbon dioxide in patients under anesthesia and apnea compared to standard apnea oxygenation [28]. However, we did not measure the carbon dioxide indices at each time point, and we could not evaluate the effect of THRIVE in improving carbon dioxide accumulation. Fourth, it is unclear if THRIVE may still be utilized safely in lengthier surgical procedures that preserve spontaneous breathing because the gastroscopy in both groups in this trial lasted less than 10 min. Additionally, it might conceal THRIVE’s leading role in promoting gas exchange. In addition, the traditional nasal cannula oxygen therapy is more convenience and accomplished with ease than THRIVE, which may limit the wild application of THRIVE.

Conclusion

When compared to nasal cannula oxygen, THRIVE had no discernible impact on the hemodynamic alterations that occurred during a painless gastroscopy in children aged 6 to 12 years in this study. THRIVE, on the other hand, can lessen the incidence and duration of hypoxemia during painless gastroscopy. The prevalence of impaired breathing and the necessity for measures to deal with hypoxemia was considerably reduced in children who utilized THRIVE as an oxygen source

Abbreviations

ASA

American society of anesthesiologists

THRIVE

Transnasal humidified rapid-insufflation ventilatory exchange

NC

Nasal cannula

BMI

Body mass index

ECG

Electrocardiogram

FiO2

Fraction of inspiration oxygen

OAA/S

Observer Assessment of Alertness/Sedation

SpO2

Pulse oxygen saturation

RR

Respiration rate

HR

Heart rate

MAP

Mean arterial pressure

HFNC

High-flow nasal cannula therapy

CPAP

Continuous positive airway pressure

PaO2

Partial pressure of oxygen in arterial blood

SaO2

Oxygen saturation in arterial blood

Author contributions

HG and FC: conceptualization and visualization; HG, JZ, and RW: data curation. CY and HG: Formal analysis. FC and JZ: methodology. LW and RW: investigation. CY and LW: supervision. LW and RW: validation. HG: Writing —original draft. All authors wrote, reviewed, and edited the manuscript; contributed to the article; and approved the submitted version.

Funding

This study was supported by the Shenzhen Fundamental Research and Discipline Layout Project (JCY20180228175338115).

Data availability

All data presented in this manuscript is available from the corresponding author upon reasonable request.

Declarations

Ethics approval and consent to participate

This study was approved by the Ethics Committee of Shenzhen Children’s Hospital (reference number: 2021087,09/09/2021 Chairperson Xin Qi) and registered in the China Clinical Trial Center (ChiCTR2200060799,12/06/2022), Written informed consent to participate in this study was provided by the participants’ legal guardian/next of kin.

Consent for publication

Not applicable.

Competing interests

The authors declare no competing interests.