High-flow nasal oxygenation for anesthetic management / 대한마취과학회지

High-flow nasal oxygenation (HFNO) is a promising new technique for anesthesiologists. The use of HFNO during the induction of anesthesia and during upper airway surgeries has been initiated, and its applications have been rapidly growing ever since. The advantages of this technique include its easy set-up, high tolerability, and its abilities to produce positive airway pressure and a high fraction of inspired oxygen and to influence the clearance of carbon dioxide to some extent. HFNO, via a nasal cannula, can provide oxygen both to patients who can breathe spontaneously and to those who are apneic; further, this technique does not interfere with bag-mask ventilation, attempts at laryngoscopy for tracheal intubation, and surgical procedures conducted in the airway. In this review, we describe the techniques associated with HFNO and the advantages and disadvantages of HFNO based on the current state of knowledge.

Effect of preoxygenation and apnoeic oxygenation during intubation in the critically ill patients: a network Meta-analysis / 中华危重病急救医学

Objective@#To systematic review the effect of preoxygenation (PreOx) and apnoeic oxygenation (ApOx) during intubation in the critically ill patients by network Meta-analysis.@*Methods@#The PubMed, Embase, the Cochrane Library, CNKI and Wanfang Data were searched by computer to collect randomized controlled trials (RCT) of PreOx and ApOx techniques in the intensive care unit (ICU) from inception to January 30th, 2019. PreOx techniques (p) included nasal cannula (NC), high flow nasal cannula (HFNC), bag valve mask (BVM), bi-level positive airway pressure (BiPAP), non-rebreather mask (NRM) and non-invasive ventilation (NIV), etc.; ApOx technique (a) referred to HFNC. Experimental group strategy was PreOx combined with ApOx, and control group strategy was PreOx alone. The outcomes were as follows: the lowest value of pulse oximetry (SpO2) during the intubation procedure, the incidence of severe desaturations (SpO2 < 0.80), and severe intubation-related complications [including SpO2 < 0.80, systolic blood pressure < 80 mmHg (1 mmHg = 0.133 kPa), vasopressor 30% dose increment, cardiac arrest and death]. Two reviewers independently screened literature, extracted data and assessed the risk of bias of included studies. Statistic analysis was performed by RevMan 5.3 software, Stata 15.1 software and WinBUGS 1.4.3 software.@*Results@#A total of 7 RCTs involving 796 patients were included. Meta-analysis showed that, compared with the control group, the lowest SpO2 in the experimental group was significantly increased [mean difference (MD) = 1.42, 95% confidence interval (95%CI) was 0.60 to 2.25, P = 0.000 7], the incidence of severe complications was significantly decreased [odds ratio (OR) = 0.54, 95%CI was 0.32 to 0.92, P = 0.02], but the incidence of SpO2 < 0.80 did not improve significantly (OR = 0.65, 95%CI was 0.40 to 1.05, P = 0.08). The network Meta-analysis showed that, compared with non-pressure mask (NPM)p, (HFNC+NIV)p+HFNCa (OR = 51.20, 95%CI was 2.06 to 3 518.68) and NIVp (OR = 5.80, 95%CI was 1.25 to 34.70) had a significant reduction in the incidence of SpO2 < 0.80 (both P < 0.05). There were no significant differences in the incidence of severe complications during intubation among (HFNC+NIV)p+HFNCa, HFNCp+HFNCa, NIVp and NPMp. The occurrence rate of SpO2 < 0.80 and severe complications using different oxygenation techniques decreased sequentially in NPMp, HFNCp+HFNCa, NIVp and (HFNC+NIV)p+HFNCa.@*Conclusion@#(HFNC+NIV)p+HFNCa should be of a priority choice for critically ill patients during intubation.

Effect of preoxygenation and apnoeic oxygenation during intubation in the critically ill patients: a network Meta-analysis / 中华危重病急救医学

Objective To systematic review the effect of preoxygenation (PreOx) and apnoeic oxygenation (ApOx) during intubation in the critically ill patients by network Meta-analysis. Methods The PubMed, Embase, the Cochrane Library, CNKI and Wanfang Data were searched by computer to collect randomized controlled trials (RCT) of PreOx and ApOx techniques in the intensive care unit (ICU) from inception to January 30th, 2019. PreOx techniques (p) included nasal cannula (NC), high flow nasal cannula (HFNC), bag valve mask (BVM), bi-level positive airway pressure (BiPAP), non-rebreather mask (NRM) and non-invasive ventilation (NIV), etc.; ApOx technique (a) referred to HFNC. Experimental group strategy was PreOx combined with ApOx, and control group strategy was PreOx alone. The outcomes were as follows: the lowest value of pulse oximetry (SpO2) during the intubation procedure, the incidence of severe desaturations (SpO2 < 0.80), and severe intubation-related complications [including SpO2 < 0.80, systolic blood pressure < 80 mmHg (1 mmHg = 0.133 kPa), vasopressor 30% dose increment, cardiac arrest and death]. Two reviewers independently screened literature, extracted data and assessed the risk of bias of included studies. Statistic analysis was performed by RevMan 5.3 software, Stata 15.1 software and WinBUGS 1.4.3 software. Results A total of 7 RCTs involving 796 patients were included. Meta-analysis showed that, compared with the control group, the lowest SpO2 in the experimental group was significantly increased [mean difference (MD) = 1.42, 95% confidence interval (95%CI) was 0.60 to 2.25, P = 0.000 7], the incidence of severe complications was significantly decreased [odds ratio (OR) = 0.54, 95%CI was 0.32 to 0.92, P = 0.02], but the incidence of SpO2 < 0.80 did not improve significantly (OR = 0.65, 95%CI was 0.40 to 1.05, P = 0.08). The network Meta-analysis showed that, compared with non-pressure mask (NPM)p, (HFNC+NIV)p+HFNCa (OR = 51.20, 95%CI was 2.06 to 3 518.68) and NIVp (OR = 5.80, 95%CI was 1.25 to 34.70) had a significant reduction in the incidence of SpO2 < 0.80 (both P < 0.05). There were no significant differences in the incidence of severe complications during intubation among (HFNC+NIV)p+HFNCa, HFNCp+HFNCa, NIVp and NPMp. The occurrence rate of SpO2 < 0.80 and severe complications using different oxygenation techniques decreased sequentially in NPMp, HFNCp+HFNCa, NIVp and (HFNC+NIV)p+HFNCa. Conclusion (HFNC+NIV)p+HFNCa should be of a priority choice for critically ill patients during intubation.

Effect of preoxygenation and apnoeic oxygenation during intubation in the critically ill patients: a network Meta-analysis / 中华危重病急救医学

Objective To systematic review the effect of preoxygenation (PreOx) and apnoeic oxygenation (ApOx) during intubation in the critically ill patients by network Meta-analysis. Methods The PubMed, Embase, the Cochrane Library, CNKI and Wanfang Data were searched by computer to collect randomized controlled trials (RCT) of PreOx and ApOx techniques in the intensive care unit (ICU) from inception to January 30th, 2019. PreOx techniques (p) included nasal cannula (NC), high flow nasal cannula (HFNC), bag valve mask (BVM), bi-level positive airway pressure (BiPAP), non-rebreather mask (NRM) and non-invasive ventilation (NIV), etc.; ApOx technique (a) referred to HFNC. Experimental group strategy was PreOx combined with ApOx, and control group strategy was PreOx alone. The outcomes were as follows: the lowest value of pulse oximetry (SpO2) during the intubation procedure, the incidence of severe desaturations (SpO2 < 0.80), and severe intubation-related complications [including SpO2 < 0.80, systolic blood pressure < 80 mmHg (1 mmHg = 0.133 kPa), vasopressor 30% dose increment, cardiac arrest and death]. Two reviewers independently screened literature, extracted data and assessed the risk of bias of included studies. Statistic analysis was performed by RevMan 5.3 software, Stata 15.1 software and WinBUGS 1.4.3 software. Results A total of 7 RCTs involving 796 patients were included. Meta-analysis showed that, compared with the control group, the lowest SpO2 in the experimental group was significantly increased [mean difference (MD) = 1.42, 95% confidence interval (95%CI) was 0.60 to 2.25, P = 0.000 7], the incidence of severe complications was significantly decreased [odds ratio (OR) = 0.54, 95%CI was 0.32 to 0.92, P = 0.02], but the incidence of SpO2 < 0.80 did not improve significantly (OR = 0.65, 95%CI was 0.40 to 1.05, P = 0.08). The network Meta-analysis showed that, compared with non-pressure mask (NPM)p, (HFNC+NIV)p+HFNCa (OR = 51.20, 95%CI was 2.06 to 3 518.68) and NIVp (OR = 5.80, 95%CI was 1.25 to 34.70) had a significant reduction in the incidence of SpO2 < 0.80 (both P < 0.05). There were no significant differences in the incidence of severe complications during intubation among (HFNC+NIV)p+HFNCa, HFNCp+HFNCa, NIVp and NPMp. The occurrence rate of SpO2 < 0.80 and severe complications using different oxygenation techniques decreased sequentially in NPMp, HFNCp+HFNCa, NIVp and (HFNC+NIV)p+HFNCa. Conclusion (HFNC+NIV)p+HFNCa should be of a priority choice for critically ill patients during intubation.

Utilización de la oxigenación apneica en la simpatectomía transtorácica endoscópica / Use of apneic oxygenation in endoscopic transthoracic sympathectomy

Introducción: Es aún controversial la conducta anestésica de los pacientes tratados por toracoscopia para tratamiento quirúrgico de las hiperhidrosis en los miembros superiores. Objetivos: Identificar el comportamiento de los niveles de oxigenación y del dióxido de carbono al final de la espiración, así como los posibles efectos adversos al aplicar la técnica de Oxigenación Apneica en pacientes que se les realizará simpatectomía transtorácica endoscópica T2-T3. Material y Método: Se realizó un estudio descriptivo, transversal en 16 pacientes a los que se les aplicó la oxigenación apneica empleando tubo orotraqueal convencional. En el intraoperatorio se midió el tiempo de apnea por hemitórax y se evaluó la saturación periférica arterial de oxigeno (SpO2) y el dióxido de carbono al final de la espiración (etCO2), además de la frecuencia cardiaca (FC) y la tensión arterial no invasiva (TA). Resultados: a pesar de los tiempos de apnea la oxigenación se mantuvo óptima en todos los casos, el valor medio del etCO2 no supera los 60 mmHg y no se encontraron cambios significativos de la FC y TA con respecto a los valores basales. Conclusiones: La técnica de Oxigenación Apneica es útil en este tipo de procedimiento.

Even now it is arguable the anesthetic behavior of patients underwent thoracoscopy for a surgical treatment of hyperhidrosis of upper extremities. Objectives: To identify the behavior of oxygenation and carbon dioxide (CO2 ) at the end of the exhalation, as well as the potential side effects with the application of apneic oxygenation in patients in which a T2-T3 endoscopic transthoracic sympathectomy will be carried out. Material and Methods: A cross-sectional and descriptive study was conducted in 16 patients underwent apneic oxygenation using a conventional orotracheal tube. At intraoperative period the apnea time was measured by hemithorax and the arterial peripheral oxygen saturation (Sp02) was assessed and the carbon dioxide at the end of the exhalation (etCO2), as well as the heart rate (HR) and the non-invasive blood pressure (BP). Results: Despite the apnea times the oxygenation remained optimal in all the cases, the mean value of etCO2 in under the 60 mmHg without significant changes of HR and the BP regarding the basal values. Conclusions: The apneic oxygenation technique is useful in this type of procedure.

Changes of Heart Rate, Blood Pressure, and Plasma Catecholamine Levels in Rabbits during the Apneic Oxygenation / 대한구급학회지

BACKGROUND: Permissive hypercapnia and apneic oxygenation are used to provide oxygen to patient without active ventilation. It is well known that hypercapnia induces the release of endogenous catecholamines. However, it is unclear that how much or what kind of catecholamines are released. The aim of this study was to observe changes of basic hemodynamic parameters and plasma catecholamine concentration during apneic oxygenation. METHODS: Twenty-one rabbits weighing 2.0~3.0 kg were anesthetized with 100% oxygen and isoflurane. 0.05 mg/kg of atropine was injected and endotracheal intubation was done. 1 mg/kg/hr of vecuronium was infused during the experiment. The anesthesia and apneic oxygenation was maintained with 100% oxygen and 2 vol% isoflurane under 1 cmH2O PEEP using continuous positive airway pressure device. During the apneic oxygenation, blood pressure, heart rate, and plasma catecholamine concentration were measured every 10 min using High Performance Liquid Chromatography. RESULTS: Systolic blood pressure was significantly increased but diastolic blood pressure was not changed until post-apneic 40 min. After then, both systolic and diastolic blood pressure were significantly decreased. At post-apneic 10 min, heart rate was dramatically decreased and slowly recovered to the level of control data until post-apneic 60 min. Plasma epinephrine level was increased higher than that of norepinephrine by 3 to 4 times. CONCLUSIONS: Epinephrine may play more important role than norepinephrine to compensate the cardiovascular depressive effects of hypercapnia during the apneic oxygenation in rabbits.

Effect of Nasal Insufflation of Oxygen on Arterial Oxygen and Carbon Dioxide Tension during Apnea in Anesthetized Humans / 대한마취과학회지

During induction of anesthesia, apnea may persist in the case of difficult intubation or fiberoptic guide intubation. In that situation hypoxemia and hypercarbia may occur even though preoxygenation and hyperventilation has performed before apnea start. Sometimes anesthesiologist perform preoxygenation with mixed oxygen and nitrous oxide gas to facilitate and smooth induction. The aim of this study was to know the apnenic time that arterial oxygen saturation drop below 9%o in the patients who was preoxygenated with 100% oxygen or mixed gas (oxygen-nitrous oxide 1:1 ratio) before apnea begin and to know whether nasal oxygen insufflation during apnea affect arterial oxygen tension. Study was conducted in three groups. Each group has 13 patients, After induction of anesthesia with thiopental, pancuronium and isoflurane 1 vol%, Group 1 (Air group) and Group 2 (O2 group) were ventilated with facemask with 100% oxygen for 5 minutes and then remained apneic state in air (Group 1) or nasal insufflation of oxygen (1 L/10 kg/min) (Group 2) with patent airway. Group 3 (N group) was ventilated with O2 and N2O in 1: 1 ratio for 5 minutes and remained apneic state in air. Apnea continued until either SaO2 dropped to 93%, or 8 min had elapsed. At this time, duration of apnea and minimum SaO2 were recorded. During apnea period PaC2, PaCO2, SaO2, MAP, HR were measured 1 min interval. Duration of apnea and mean minimum saturation for Group 1, 2 and 3 were 7+/-1, 8, 3.0+/-0.9 min and 96.6+/-2.4%, 99.1+/-1.5%, 95.7+/-2.5% (mean+/-SD) respectively. In Group 2, SaO2 never fell below 95% during the entire 8 min apnea in any subject. PaCO2 were increased by 5.8 mmHg (Group 1), 7.4 mmHg (Group 2), 7.8 mmHg (Group 3) at first 1 min and then linealy increased by 2.9 mmHg/min for Group 1 and 2 and by 3.2 mmHg/min in Group 3 during apnea period. There was no difference in MAP among three groups during apneic period but HR of Group 3 showed significant increase after 2 min compared to Group 2. In conclusion, preoxygenation followed by insufflation of oxygen via nasal oxygen cannula provides at least 8 min of adequate oxygenation in healthy apneic patients whose airways are unobstructed in whom the trachea is not intubated. It is safe method not to use preoxygenation with mixed gas of N2O before apnea if there is any possibilty of difficult intubation or difficulty in establishing patent airway.

An Experimental Study on the Extracorporeal Carbon Dioxide Removal with a Double Lumen Tube / 대한마취과학회지

Intermittent positive pressure ventilation is used as a respiratory support for acute respiratroy failure. Adult respiratory distress syndrome(ARDS) revealed mortality rate of 70% as yet. Hypoxemia is foremost problem in ARDS. Though various ventilatory support is tried on ARDS, extracorporeal membrane oxygenation(ECMO) is to be recommended when hypoxemia and hypercarbia are refractory to conventional treatments. Neonatal venoarterial (VA) ECMO in USA is recognized as a therapeutic modality for neonatal respiratory failure and extracorporeal carhon dioxide removal(ECCO2R) in Europe is used for adult respiratory distress syndome. The partial bypass using the membrane oxygenator aims at lung rest while relieving the hard ventilatory setting on the diseased lung. VA ECMO can provide circulatory support as well but the right internal jugular vein and the right common carotid artery are ligated for the cannulation of draiaage and perfusion catheters. Recent follow up study shows that VA ECMO may not be completely free from neurologic complications such as embolism in the systemic circulation and ill effects due to the reduction of blood supply to the immature lungs. ECCO2R adopts low-flow venovenous(VV) bypass. It has been reported to be valuable for treatment of neonatal respiratory failure. VV bypass provides gas exchange but no cardiac support. Venous drainage and perfusion catheters are placed in the right atrium or vena cavae via the femoral or internal jugular veins. Compared to VA bypass, the consequences of embolizations are potentially fewer, no major artery is sacrificed. Highly oxygenated blood flows into pulmonary eirculatiom which may relieve pulmonary artery hypertension. Total respiratory support may be obtained by VV bypass, VV bypass requires approximately 20-50% more flow for total respiratory sopport due to recirculation of oxygenated blood. Recently VV bypass is chosen for neonatal resyiratoty failure in USA. They alliveate the entry criteria for ECMO using the parameter of oxygenation index(OI). VV ECCO2R using to-and-fro system is tried also for neonatal respiratory failure in Europe. A double lumen tube was developed to reduce the number of veins to be cannulated during VV bypass. It is constructed with the outer drainage cannula( 14 Fr.) and the inner perfusion cannula( 8 Fr.) whose opening is placed on the left side of outer cannula. If perfusion opening is placed on the right atrium facing the right ventricle, the venous blood can be drained from both superior and inferior vena cavae through several drainage opening. To evaluate the effectiveness of ECCO2R with a double lumen tube, we developed an experimental model of acute respiratory failure on 8 mongrel dogs. Under general anesthesia with i.v, pentobarbital, a double lumen tube was introduced via the right internal jugular vein and it was connected with the extracorporeal circuit. Without ventilating the oxygenator during VV bypass, respiratory failure was induced by hypoventilation. After obtaining control hemodynamic and blood gas values under hypoventilation, we proceed to apneic oxygenation(AO), extracorporeal CO2 removal(ECCO2R) and controlled mechanical ventilation(CMV) in that order. Arterial pH in control was 7.180.09(meanSD), and it was increased to 7.33+/-0.08 and 7.28+/-0.08 in ECCO2R and CMV, respectively. PaCO2 in control was 69+/-9mmHg and it was decreased to 41+/-4mmHg and 47+/-7mmHg in ECCO R and CMV respectively. PaCO2 in control was 62+/-15 mmHg and it was increased in AO, ECCO2R and CMV. Mixed venous blood gas analysis showed the same result as arterial blood gas analysis. There was no difference between ECCO2R and CMV. The bypass flow enough to remove CO2 was 30-50% of cardiac output. It is concluded that ECCO2R using a double lumen tube was effective to control the carbon dioxide tension in arterial blood, and a double lumen tube may permit the simplicity of an operation and patient care as well as minimizing the bleeding during extracorporeal respiratory support.

The Apnea Test for the Determination of Brain Death

By the criteria for the determination of brain deathe established in The Korean Medical Association, an appneic patient's PaCO2 must be greater than 50 torr before apnea can be attributed to brain death. Blood gases were analized in 35cases of brain death by the conventional criteria. The data of PaCO2, pH, PaCO2 in the apnea test of the cases were erratic, but a PaCO2 had increased 50 torr in each patient esaily. To perform the apnea test satisfactorily, it is essential to keep oxygen catheter deep into the tracheal tube by at least 10cm for adequate appneic oxygenation, and indwelling arterial catheters were available for rapid, timed blood sampling. And to determine the accuracy of blood gas measurements, duplicate samples drawn less than 4seconds apart were sent to clinical lagoratory in each test. The apneic test is a crucial rapid and safe performance for the determination of brain death. I recognize.

Gas Exchange during Apneic Oxygenation / 대한마취과학회지

Arterial and mixed venous blood gases were investigated during apnea in anesthetized paralyzed mongrel dogs. Dogs were ventilated with 100% oxygen after endotracheal intubation by intermittent positive pressure ventilation over 30 minutes before apnea. Femoral artery was cannulated for arterial blood gas analysis and Swan-Ganz catheter was inserted through femoral vein to draw mixed venous blood for gas analysis. In group 1 (n=6), the endotracheal tube was left open to room air during apnea and blood gas analysis were measured at 1 minute interval. In group 2 (n=6), the endotracheal tube was left connected to the respirator with 100% oxygen with 1 L/kg/min flow during apnea and blood gas analysis were checked at 5 minute interval. Blood sampling was continued until cardiac problem occured. In group1, PaO2,fall rapidly below 100 mmHg in 5 minutes and PaCO2, increased by the rate of 5.2 mmHg/min, In group 2, PaO2, fall slowly in proportion to increase of PaCO2, that rised in the rate of 4.1 mmHg/min, but hypoxemia does not occured until 45 minutes. In conclusion, arterial oxygenation can be maintained for long duration with oxygen flow through endotracheal tube but arterial carbon dioxide tension increase continuously during apnea. Useful methods to avoid carbon dioxide accumulation should be sought and investigated for clinical use of apneic oxygenation.

Gas Exchange during Apneic Oxygenation / 대한마취과학회지

Arterial and mixed venous blood gases were investigated during apnea in anesthetized paralyzed mongrel dogs. Dogs were ventilated with 100% oxygen after endotracheal intubation by intermittent positive pressure ventilation over 30 minutes before apnea. Femoral artery was cannulated for arterial blood gas analysis and Swan-Ganz catheter was inserted through femoral vein to draw mixed venous blood for gas analysis. In group 1 (n=6), the endotracheal tube was left open to room air during apnea and blood gas analysis were measured at 1 minute interval. In group 2 (n=6), the endotracheal tube was left connected to the respirator with 100% oxygen with 1 L/kg/min flow during apnea and blood gas analysis were checked at 5 minute interval. Blood sampling was continued until cardiac problem occured. In group1, PaO2,fall rapidly below 100 mmHg in 5 minutes and PaCO2, increased by the rate of 5.2 mmHg/min, In group 2, PaO2, fall slowly in proportion to increase of PaCO2, that rised in the rate of 4.1 mmHg/min, but hypoxemia does not occured until 45 minutes. In conclusion, arterial oxygenation can be maintained for long duration with oxygen flow through endotracheal tube but arterial carbon dioxide tension increase continuously during apnea. Useful methods to avoid carbon dioxide accumulation should be sought and investigated for clinical use of apneic oxygenation.