Effect of High-flow vs. Low-flow Nasal Oxygenation on Spontaneous Ventilation in Obese Adult Patients During Analgo-sedation for Vitrectomy, Randomized Controlled Trial
试验速览
- 阶段
- 不适用
- 发起方
- 入组人数
- 126
- 试验地点
- 1
- 主要终点
- Maintaining oxygenation above the level of hypoxemia. Measure: peripheral blood saturation (SpO2) 5 minutes after discontinuing analgo-sedation and oxygenation (LFNO and HFNO).
研究概览
简要总结
Patients suffering from pathology of posterior eye chamber such as diabetic retinopathy, retinal detachment, traumatic eye injury, retained lens fragments, macular hole, pucker, dislocated intraocular lens after cataract surgery or vitreomacular traction are often subjected to pars plana vitrectomy (PPV). PPV is minimally invasive endo-microscopic operation usually performed in topical anesthesia combined with sub-Tenon or retrobulbar block done by surgeon, supplemented by intravenous analgo-sedation given by anesthesiologist.
Continuous infusion and dose adjustment of intravenous anesthetics applied should procure moderate sedation and preservation of patients' spontaneous ventilation. However, despite carefully applied anesthetics and standard low-flow nasal oxygenation (LFNO) (5 L/min O2 via nasal catheter), inadequate spontaneous breathing can occur leading to low blood oxygen level (hypoxia). Obese patients are susceptible to hypoxia and hypercapnia (high CO2 blood level) during analgo-sedation. Respiratory instability of obese patients is often associated to their subsequent circulatory instability (heart rate and blood pressure disorders).
On the other hand, high-flow nasal oxygenation (HFNO) is usually used during anesthesia induction when difficult maintenance of airway patency is expected, in intensive care units during weaning patients from mechanical respirator and in postanesthesia care units during awakening from anesthesia. It can deliver 20 to 70 L/min, up to 100% inspiratory fraction of O2 (FiO2) to patient. High oxygen/air flow produces 3-7 cmH2O of continuous pressure in patients' upper airways therefore providing better oxygenation. Oxygen/air mixture delivered by HFNO is humidified and heated, thus more comfortable to patient than dry and cold LFNO.
Aim of this study is to compare effect of HFNO to LFNO during intravenously applied standardized analgo-sedation given for PPV in obese adult patients.
Investigators hypothesize that obese patients, whose breathing pattern is preserved, receiving HFNO vs. LFNO during standardized analgo-sedation for PPV will be more respiratory and circulatory stable, preserving normal blood O2 and CO2 level, breathing pattern, heart rate and blood pressure.
详细描述
Patients suffering from pathology of posterior eye chamber such as diabetic retinopathy, retinal detachment, traumatic eye injury, retained lens fragments, macular hole, pucker, dislocated intraocular lens after cataract surgery or vitreomacular traction are often subjected to pars plana vitrectomy (PPV).
PPV is minimally invasive micro-endoscopic surgery of posterior eye chamber. Patients usually receive analgo-sedation combined with topical anesthesia, which, depending on the type of surgery, precedes a regional, retrobulbar or sub-Tenon block. Although lower doses of intravenous anesthetics are carefully titrated in continuous infusion and standard, low - flow nasal oxygenation (LFNO) is applied, patients are prone to respiratory insufficiency. Obese patients are especially susceptible to bradypnoea, transitory apnoea, hypoxia and hypercapnia. Respiratory instability is then often followed by circulatory one presented by heart rate and blood pressure deflections from baseline values. It is known that higher anesthesia risk obese patients may suffer from serious complications due to respiratory issues during analgo-sedation, even fatal outcome may occur.
LFNO is applied at rate of 5 L/min O2 per nasal catheter, reaching inspiratory fraction of oxygen (FiO2) of 40%. High-flow nasal oxygenation (HFNO) is an innovative method of patient oxygenation that delivers warmed and moistened oxygen and air mixture with a flow rate of up to 70 L/min and up to 100% FiO2 via specially designed soft nasal cannula. It is known that 40 L/min of oxygen/air mixture delivered by HFNO provides 40% FiO2 applying continuous positive inspiratory pressure of 3-7 cmH2O which ensures continuous non-invasive support of patients' spontaneous ventilation and thus better oxygenation stability of the patient.
OBJECTIVE: The study aims to determine the effect of HFNO versus LFNO on the stability of spontaneous ventilation during standardized intravenous analgo-sedation for PPV in normal weight and obese patients.
HYPOTHESIS: Investigators hypothesize that administration of HFNO in comparison with LFNO in patients with preserved spontaneous breathing during the standard analgo-sedation procedure will contribute to better oxygenation maintenance and, consequently, greater peri-procedural safety of patients, especially in obese patients.
研究设计
- 研究类型
- Interventional
- 分配方式
- Randomized
- 干预模型
- Parallel
- 主要目的
- Treatment
- 盲法
- Double (Investigator, Outcomes Assessor)
盲法说明
Anesthesiologist who interviews and examines patients scheduled for PPV under analgo-sedation will enroll eligible participants and offer procedure explanation with possibility to sign uniformed written consent. Unique personal hospital admission number (UPHAN) will be assigned to all eligible participants. Participants will be randomized to control or intervention group by using random numbers generator. Anesthesiologist who implements anesthesia will receive nontransparent envelope with assigned intervention provided by independent investigator and will not decide which participant will receive LFNO or HFNO. However, attending anesthesiologist and participants will unavoidably be aware of type of oxygenation applied. Collected data are objective measures. Investigator who collects data after procedure will be unaware of study protocol and will enter data to formatted database. Participants' data will be noted under UPHAN. Outcome assessors will be unaware of intervention applied.
入排标准
- 年龄范围
- 18 Years 至 —（Adult, Older Adult）
- 性别
- All
- 接受健康志愿者
- 否
入选标准
- •Normal weight and obese patients (18<BMI<30 kg/m2, 30≤BMI<35 kg/m2, BMI≥35 kg/m2)
- •Moderate intravenous analgo-sedation
- •Pars plana vitrectomy
排除标准
- •Higher anesthesia risk patients (ASA III)
- •Conventional vitrectomy
- •Diseases of peripheral blood vessels
- •Hematological diseases
- •Psychiatric diseases
- •Sideropenic anemia
- •Patient's refusal
- •Ongoing chemotherapy or irradiation
- •Remifentanyl and Xomolix allergies
研究组 & 干预措施
Active Comparator: 30≤BMI<35 kg/m2 - LFNO
Low-flow nasal oxygenation (LFNO) O2 flow 5L/min, FiO2 40%
干预措施: Device: low-flow nasal oxygenation (LFNO) 30≤BMI<35 kg/m2 (Device)
Active Comparator: 18<BMI<30 - LFNO
Low-flow nasal oxygenation (LFNO) O2 flow 5L/min, FiO2 40%
干预措施: Device: low-flow nasal oxygenation (LFNO) 18<BMI<30 kg/m2 (Device)
Active Comparator: BMI≥35 kg/m2 - LFNO
Low-flow nasal oxygenation (LFNO) O2 flow 5L/min, FiO2 40%
干预措施: Device: low-flow nasal oxygenation (LFNO) BMI≥35 kg/m2 (Device)
Experimental: 18<BMI<30 kg/m2 - HFNO
High Flow nasal oxygenation (HFNO) O2 flow 40L/min, FiO2 40%
干预措施: Device: High-flow nasal oxygenation (HFNO) 18<BMI<30 kg/m2 (Device)
Experimental: 30≤BMI<35 kg/m2 - HFNO
High Flow nasal oxygenation (HFNO) O2 flow 40L/min, FiO2 40%
干预措施: Device: High-flow nasal oxygenation (HFNO) 30≤BMI<35 kg/m2 (Device)
Experimental: BMI≥35 kg/m2 - HFNO
High Flow nasal oxygenation (HFNO) O2 flow 40L/min, FiO2 40%
干预措施: Device: High-flow nasal oxygenation (HFNO) BMI≥35 kg/m2 (Device)
结局指标
主要结局
Maintaining oxygenation above the level of hypoxemia. Measure: peripheral blood saturation (SpO2) 5 minutes after discontinuing analgo-sedation and oxygenation (LFNO and HFNO).
时间窗: Time 2=5 minutes after discontinuing analgo-sedation and oxygenation (LFNO and HFNO).
Normal range \>92% Acceptable deflection from normal values of peripheral blood saturation (SpO2) significant for hypoxemia is ≤92%, while all values above will be considered normal. SpO2 will be observed during procedure so that we can confirm or exclude differences connected with practical application of LFNO and HFNO.
Maintaining oxygenation above the level of hypoxemia. Measure: peripheral blood saturation (SpO2) before application of LFNO or HFNO.
时间窗: Time 0=before oxygenation
Normal range \>92% Acceptable deflection from normal values of peripheral blood saturation (SpO2) significant for hypoxemia is ≤92%, while all values above will be considered normal. SpO2 will be observed during procedure so that we can confirm or exclude differences connected with practical application of LFNO and HFNO.
Maintaining oxygenation above the level of hypoxemia. Measure: peripheral blood saturation (SpO2) 15 minutes after institution of LFNO or HFNO.
时间窗: Time 1=15 minutes after institution of LFNO or HFNO,
Normal range \>92% Acceptable deflection from normal values of peripheral blood saturation (SpO2) significant for hypoxemia is ≤92%, while all values above will be considered normal. SpO2 will be observed during procedure so that we can confirm or exclude differences connected with practical application of LFNO and HFNO.
次要结局
- Maintaining of expiratory efficiency of spontaneous breathing below hypercapnia value. Measure: expiratory level of CO2 (expCO2) before oxygenation by LFNO or HFNO.(Time 0=before oxygenation by LFNO or HFNO)
- Maintaining of expiratory efficiency of spontaneous breathing below hypercapnia value. Measure: expiratory level of CO2 (expCO2) 15 minutes after institution of LFNO or HFNO.(Time 1=15 minutes after institution of LFNO or HFNO)
- Maintaining of expiratory efficiency of spontaneous breathing below hypercapnia value. Measure: expiratory level of CO2 (expCO2) 5 minutes after discontinuing analgo-sedation and oxygenation (LFNO or HFNO).(Time 2=5 minutes after discontinuing analgo-sedation and oxygenation (LFNO or HFNO).)
- Maintaining of normopnoea and spontaneous ventilation: frequency of breathing. Measure: frequency of breathing 5 minutes after discontinuing analgo-sedation and oxygenation (LFNO or HFNO).(Time 2=5 minutes after discontinuing analgo-sedation and oxygenation (LFNO or HFNO).)
- Maintaining of normopnoea and spontaneous ventilation: Duration of desaturation (DE/min) from the start until the end of analgo-sedation and oxygenation by LFNO or HFNO.(up to 1 minute (From the start until the end of analgo-sedation and oxygenation by LFNO or HFNO.))
- Circulatory stability: mean arterial pressure before oxygenation by LFNO or HFNO(Time 0=before oxygenation by LFNO or HFNO.)
- Maintaining of normopnoea and spontaneous ventilation: frequency of breathing Measure: frequency of breathing 15 minutes after institution of LFNO or HFNO.(Time 1=15 minutes after institution of LFNO or HFNO.)
- Measurement of procedural parameters: duration of analgo-sedation.(Procedure (From the start until the end of analgo-sedation.))
- Measurement of procedural parameters: duration of awakening (awaken patient).(up to 5 minutes)
- Circulatory stability: mean arterial pressure 5 minutes after discontinuing analgo-sedation and oxygenation (LFNO or HFNO).(Time 2=5 minutes after discontinuing analgo-sedation and oxygenation (LFNO or HFNO).)
- Maintaining of normopnoea and spontaneous ventilation: frequency of breathing Measure: frequency of breathing before oxygenation by LFNO or HFNO.(Time 0=before oxygenation by LFNO or HFNO.)
- Maintaining of normopnoea and spontaneous ventilation: frequency of bradypnoea during analgo-sedation and oxygenation by LFNO or HFNO (fBRP/min).(Procedure (From the start until the end of analgo-sedation and oxygenation by LFNO or HFNO.))
- Circulatory stability: heart rate 15 minutes after institution of LFNO or HFNO.(Time 1=15 minutes after institution of LFNO or HFNO.)
- Maintaining of normopnoea and spontaneous ventilation: frequency of desaturation during time of analgo-sedation and oxygenation by LFNO or HFNO.(Procedure (From the start until the end of analgo-sedation and oxygenation by LFNO or HFNO.))
- Circulatory stability: heart rate before oxygenation by LFNO or HFNO(Time 0=before oxygenation by LFNO or HFNO)
- Circulatory stability: heart rate 5 minutes after discontinuing analgo-sedation and oxygenation (LFNO or HFNO).(Time 2=5 minutes after discontinuing analgo-sedation and oxygenation (LFNO or HFNO).)
- Circulatory stability: mean arterial pressure 15 minutes after institution of LFNO or HFNO(Time 1=15 minutes after institution of LFNO or HFNO.)
研究者
Anita Vukovic
MD, specialist of anesthesiology, reanimatology and intensive care
University of Split, School of Medicine