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Objective:To study the effect of permissive hypercapnia on pulmonary infection in patients underwent thoracoscopic combined with laparoscopic radical esophagectomy.Methods:From 2018 to 2020, 90 who patients underwent thoracoscopic laparoscopy combined with radical esophagectomy were divided into 3 groups by random who number table method, including 30 patients in experimental group 1, 30 patients in experimental group 2, and 30 patients in control group.PaCO 2 was maintained in the range of 56 mmHg-65 mmHg in experimental group 1, 46 mmHg-55 mmHg in experimental group 2 and 35 mmHg-45 mmHg in control group. The peak airway pressure (Ppeak) , lung dynamic compliance (Cdyn) and oxygenation index (OI) were observed and compared among the three groups after endotracheal intubation (T1) , 30 min after right artificial pneumothorax (T2) and 30 min after right lung recruitment (T3) ;The clinical pulmonary infection score (CPIS) , serum procalcitonin (PCT) on the 1st, 4th and 7th day after operation were analyzed and compared. Results:At T2, observation group A had the highest dynamic lung compliance (25.13 ± 5.70 vs 22.28 ± 4.26 vs 19.99 ± 4.36), the fastest heart rate (102.04 ± 10.91 vs 96.46 ± 9.91 vs 92.28 ± 8.08) and the lowest airway pressure (17.62 ± 1.79 vs 18.96 ± 1.90 vs 20.39 ± 1.71) ( P < 0.05). Observation group A had the lowest CPIS on the 1st, 4th and 7th day after operation compared with observation group B and control group (1.12±0.77 vs 1.71±0.90 vs 2.64±1.07) (6.08±1.20 vs 7.43±1.10 vs 8.31±1.55) (1.69±1.12 vs 2.32±0.98 vs 3.44±1.25) ( P<0.05) . Conclusion:Permissive hypercapnia can reduce airway resistance, improve lung compliance and reduce the risk of postoperative pulmonary infection.
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Postoperative pulmonary complications draws anesthetists' attention as it can be associated with prolonged postoperative hospital stays, increased hospitalization expense, retardeding postoperative recovery and increased hospital mortality. In recent years, lung protective ventilation strategy has been applied during operation under general anesthesia, and current protective lung ventilation strategies generally involve some degree of hypercapnia. Increasing evidences support that hypercapnia is well tolerated and hypercapnia can attenuate the inflammatory response during lung injury, which would assign it a specific role within lung protection strategies during mechanical ventilation. In this paper, we summarize the influence of permissive hypercapnia on the body and the research development in the application of permissive hypercapnia in general anesthesia.
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Objective To investigate the significance of permissive hypercapnia( PHC) in the treat-ment of neonates with respiratory failure using synchronized nasal intermittent positive pressure ventilation. Methods A retrospective study was conducted in 47 neonates with respiratory failure admitted to our NICU during January 2015 to December 2017. The subjects were divided into PHC group ( n =27, PaCO245 ～70 mmHg,1 mmHg=0. 133 kPa) and non-permissive hypercapnia( non-PHC) group( n=20,PaCO235～45 mmHg),respectively. The blood gas indicators(PaO2,PaCO2,PaO2/FiO2) before and after non-invasive ventilation treatment were compared;Ventilator parameters of the two groups ( PIP, PEEP, PiO2 , Ti ) were compared. Duration of oxygen therapy,non-invasive ventilation time,starting time of feeding,length of hospi-tal stay,the incidence of intracranial hemorrhage,air leakage,ventilation induced lung injury,and reintubation rate were compared between the two groups. Results After treatment,the blood gas indexes of PaO2 and OI at 24h in two groups were significantly higher than those before the treatment(P<0. 05). There was no sig-nificant difference on PaO2 and OI between two groups both before and after treatment. PaCO2 was lower in non-PHC group after treatment than that before the treatment(P<0. 05),but it showed no difference in PHC group (P>0. 05). The PIP value of the ventilator parameters in PHC group[(19. 9 ± 2. 7) mmHg] was sig-nificantly lower than that in the non-PHC group[(21. 7 ± 2. 3) mmHg](P<0. 05),and there was no statisti-cally significant difference between the two groups in the other ventilator parameters(P>0. 05). Duration of oxygen therapy,starting time of feeding,the time of using noninvasive ventilation,length of hospital stay in PHC group were shorter obviously than those in non-PHC group [ ( 79. 5 ± 10. 8 ) h vs. ( 92. 7 ± 19. 1 ) h;(34.3±8.8)hvs.(47.1±10.8)h;(67.4±12.3)hvs.(97.6±17.3)h;(11.0±4.6)dvs.(14.0±3.9) d](P<0. 05). The incidences of air leakage,and intracranial hemorrhage showed no significant difference between PHC group and non-PHC group(3/27 cases vs. 4/20 cases;3/27 cases vs. 2/20 cases)(P>0. 05). There was no significant difference between the two groups in the rate of reintubation of invasive ventilation after non-invasive ventilation failure ( 2/27 cases vs. 3/20 cases, P > 0. 05 ) . The incidence of ventilator induced lung injury was significantly lower in PHC group than that in non-PHC group ( 2/27 cases vs. 7/20 cases) ( P<0. 05 ) . Conclusion The effects of treating respiratory failure were similar in PHC group and non-PHC group. However,the PHC treatment could shorten the time of oxygen therapy,non-invasive ventila-tion time and hospitalization time,reduce the incidence of lung injury associated with ventilator. The clinical efficacy of PHC was more significant.
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Objective To investigate the application of permissive hypercapnia in the thoraco-scopic surgery of neonates with congenital esophageal atresia.Methods Thirty newborns with con-genital esophageal atresia,seventeen males,thirteen females,aged 1-5 days,weighing 1.42-3.28 kg, ASA physical status Ⅱ or Ⅲ,undergoing the thoracoscopic surgery,were randomly divided into group P and group C,n =1 5 in each group.The newborns were intratracheally intubated and adopted intravenous anesthesia combining inhalational anesthesia.FiO 2 100%,fresh gas flow 2 L/min,then adjusted the respirator parameters according to the results of airway pressure and arterial blood gas a-nalysis.Group P maintained PaCO 2 ranging at 60-80 mm Hg,group C maintained PaCO 2 ranging at 35-45 mm Hg.Arterial blood gas analysis was conducted respectively before artificial pneumothorax (T0 ),1 5 min after foundation of artificial pneumothorax (T1 ),30 min after foundation of artificial pneumothorax (T2 ),60 min after foundation of artificial pneumothorax (T3 )and 1 5 min after artifi-cial pneumothorax (T4 ).Two hours after surgery,a chest X ray photograph was taken to observe pneumothorax.The time from the end of the surgery to the ventilator weaning was recorded. Results At T1-T3 ,the PET CO 2 [(73.93 ± 3.53 )mm Hg vs.(41.53 ± 1.59 )mm Hg,(73.46 ± 3.04)mm Hg vs.(41.30±1.29)mm Hg,(74.13±2.85)mm Hg vs.(41.67 ±1.35)mm Hg]in group P were greatly higher than those in group C (P <0.05);the arterial blood pH value of group P (7.25±0.02 vs.7.38 ± 0.03,7.24 ± 0.01 vs.7.37 ± 0.03,7.25 ± 0.01 vs.7.38 ± 0.02 )were greatly lower than those in group C (P <0.05);PaCO 2 [(74.80±2.45)mm Hg vs.(41.93±1.39) mm Hg,(75.33±2.1 9)mm Hg vs.(42.01±1.31)mm Hg,(75.20±2.08)mm Hg vs.(42.13± 1.1 9)mm Hg ] were greatly higher than those in group C (P < 0.05 ).The incidence of pneumothorax of group P was obviously lower than that of group C (6.7% vs.40.0%,P <0.05 ). There was no statistically significant difference of the time from the end of surgery to the ventilator weaning [(3.6±0.6)d vs.(3.5 ±0.6)d]between the two groups.Conclusion Permissive hyper-capnia significantly reduces the incidence of pneumothorax in the thoracoscopic surgery of neonates with congenital esophageal atresia.Permissive hypercapnia (PaCO 2 60-80 mm Hg)can be safely ap-plied to the thoracoscopic surgery of neonates with congenital esophageal atresia.
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Objective To investigate the effect of permissive hypercapnia on CD4 +and CD8 +T cells of rats with acute rejection after lung transplantation. Methods Twenty-four male Wistar rats and 12 male SD rats were paired and randomly divided into 3 groups (6 pairs per group). SD and Wistar rats were used as the donors and recipients in the control group and treatment group,respectively,and Wistar rats were used as the donors and recipients in the allograft group. Acute rejection rat model of orthotopic left lung transplantation was established by Cuff method. The treatment group was treated with 50% oxygen and 8% carbon dioxide after reperfusion,but only 50% oxygen for the control group and allograft group after reperfusion. Expressions of CD4 +and CD8 +T cells in transplanted lung tissue were detected with immunohistochemical (IHC)method on 7 d after the operation. Proportion of CD4 +and CD8 +T cells in peripheral blood was detected with flow cytometry. Furthermore,levels of interleukin (IL)-2 and interferon (IFN)-γin peripheral blood were detected with enzyme-linked immune absorbent assay (ELISA). Results The IHC results showed that,compared with the control group,the expression of CD8 +T cells in transplant lung tissue of rats decreased significantly in both the treatment group and allograft group. The results of flow cytometry showed that compared with the control group,the proportion of CD8 +T cells decreased significantly in both treatment group and allograft group (both P<0.05 ). ELISA results showed that,compared with the control group,levels of IL-2 and IFN-γdecreased significantly in both treatment group and allograft group (both P<0.05 ). Conclusions Permissive hypercapnia can inhibit the acute rejection after lung transplantation through inhibiting the proliferation of CD8 +T cells and release of inflammatory cytokines in CD4 +T cells.
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Objective To study the effects of permissive hypercapnia (PHC) on inflammatory factors of pulmonary tuberculosis patients with one-lung ventilation (OLV).Methods Sixty pulmonary tuberculosis patients with selective thoracic operation who were hospitalized at Hangzhou Red-cross Hospital from October 2010 to October 2013 were randomized into three groups by means of random digits table.Twenty patients were enrolled as control group whose arterial partial pressure of carbon dioxide (PaCO2) was maintained at 35-45 mmHg (1 mmHg=0.133 kPa),20 patients as lower PHC group whose PaCO2 were maintained at 50-55 mmHg,and 20 patients as higher PHC group whose PaCO2 were maintained at 56-60 mmHg.The concentrations of serum interleukin (IL)-6 and IL-8 were measured at the time when the patients were in supine position by two-lung ventilation after induction of anesthesia (T1),15 minutes (T2) and 30 minutes after OLV (T3) in lateral position,two hours (T4) and 6 hours after operation (T5).Quantitative data were analyzed by t-test.Results IL-6 at T3 time point in the three groups increased significantly compared with T1 time point (control group:[4.94± 1.60] pg/mL vs [3.32±1.34] pg/mL,t=3.47,P＜0.01; lower PHC group:[5.38±1.42] pg/mL vs [3.69±1.35] pg/mL,t=3.86,P＜0.01; higher PHC group:[5.57±± 1.34] pg/mL vs [3.50 ± 1.22] pg/mL,t=5.11,P＜0.01).IL-8 at T4 time point increased significantly compared with T1 time point (control group:[342.09±56.12] pg/mL vs [194.58 ± 30.07] pg/mL,t =10.36,P＜0.01; lower PHC group:[349.48±43.49] pg/mL vs [193.16±26.27] pg/mL,t=13.80,P＜0.01; higher PHC group:[351.55±38.13] pg/mL vs [186.02±21.08] pg/mL,t=16.99,P＜0.01).IL-6 at the T4 and T5 time points in both lower PHC group and higher PHC group decreased significantly compared with control groupatthe same time points (T4..[38.49± 9.70] and [43.41± 9.01] pg/mL vs [62.35±7.83] pg/mL,t=8.56 and 7.10,both P＜0.01; T5:[56.39±7.47] and [54.77±7.12] pg/mL vs [107.32± 13.97] pg/mL,t=-14.38 and-14.99,both P＜0.01].Conclusions The serum IL-6 and IL-8 levels in pulmonary tuberculosis patients with OLV increase after selective thoracic operation.PHC through low tidal volume could decrease the release of IL-6 and attenuate the pulmonary inflammatory injury in the tuberculosis patients with operation.
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Objective To evaluate the effect of permissive hypercapnia on pulmonary function and in-flammatory responses of the collapsed lung of patients underwent video-assisted pulmonary lobectomy after one-lung ventilation.Methods Fifty patients,aged 38-65 years,ASA Ⅱ or Ⅲ,including 30 males and 20 females,scheduled for video-assisted pulmonary lobectomy were selected and divided into two groups ran-domly,with 25 patients in each group.During the surgery,PaCO2 of patients in group C were maintained during 35 to 45 mm Hg,while in group H the value were 55 to 65 mm Hg.The arterial blood samples were collected at 1 min before one-lung ventilate (T1 ),30 min after one-lung ventilate (T2 )and 30 min after re-flow of the collapsed lung (T3 )for arterial blood gas analysis,then the respiratory index of each patient was evaluated.Peripheral venous blood and bronchoalveolar lavage fluid draw from left lower lobar of the col-lapsed lung were collected to evaluate the levels of TNF-α,IL-6,and IL-10 at T1 ,T2 and T3 .The peak in-spiratory pressure,plateau pressure and tidal volume were also recorded to calculate lung dynamic compli-ance.Results Compared to group C,peak inspiratory pressure of group H was significantly higher;the IL-10 level of bronchoalveolar lavage fluid of the collapsed lung and the pulmonary dynamic compliance of group H were significantly higher at T2 and T3 ,and the concentrations of TNF-α,IL-6 of bronchoalveolar lavage fluid,the peak pressure,and respiratory index of group H were lower significantly at the same point of time (P <0.05).Conclusion Permissive hypercapnia would inhibit inflammation response of collapsed lung after one-lung ventilation effectively,improve lung diffusion capacity and pulmonary compliance.
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PURPOSE: Lung injury from mechanical ventilation is one of the major pathogenetic factors of bronchopulmonary dysplasia. Permissive hypercapnia (PH) is one of the strategies for reducing lung injury. However, PH is frequently infeasible in very low birth weight infants (VLBWI) due to their immature renal compensation for respiratory acidosis. The purpose of this study was to identify time when metabolic compensation for hypercapnia begin to occur in VLBWIs. METHODS: Data were retrospectively collected from 82 VLBWI who were admitted to Seoul National University Bundang Hospital from January 2011 to December 2012. The postnatal day when the difference between actual bicarbonate and expected bicarbonate levels became less than 2.0 mmol/L consistently for the first time under hypercapnea (>40 mmHg) was defined as the time when metabolic compensation for hypercapnea occurred. RESULTS: Metabolic compensation for hypercapnea occurred on 9.1+/-3.9 postnatal day. The younger the gestational age (GA) was and the smaller the birth weight was, the later metabolic compensation for hypercapnea occurred. Late metabolic compensators (> or =9 days) were significantly younger in GA (P=0.001), lighter at birth (P=0.041), intubated longer (P=0.002), and less frequently afflicted with respiratory distress syndrome (P=0.036) compared to early metabolic compensators (<9 days). However, logistic regression analysis revealed only young GA was associated with late metabolic compensation with marginal significance (P=0.068). CONCLUSION: Metabolic compensation for hypercapnea occurred 9 days after birth on average. PH strategy for reducing lung injury should be considered after renal metabolic compensation for hypercapnea occurs in VLBWI.
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Humans , Infant , Infant, Newborn , Acidosis, Respiratory , Birth Weight , Bronchopulmonary Dysplasia , Compensation and Redress , Gestational Age , Hydrogen-Ion Concentration , Hypercapnia , Infant, Very Low Birth Weight , Logistic Models , Lung Injury , Parturition , Respiration, Artificial , Retrospective StudiesABSTRACT
Mechanical ventilation can increase the survival rate of acute lung injury significantly,but the traditional ventilation can cause ventilator-induced lung injury.Permissive hypercapnia can alleviate barotrauma and volutrauma which are caused by the traditional mechanical ventilation,reduce proinflammatory or inflammatory cytokines release,decrease cell apoptosis,improve pulmonary ventilation function,regulate vascular contraction and relaxation and so on.It has a prospect in the treatment of acute lung injury.But it can suppress the immune response and alveolar epithelial repair,reduce pulmonary edema fluid absorption and other adverse effects.Those adverse effects limit clinical application of permissive hypercapnia.
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Objective To investigate the effects of permissive hypercapnia (PHC) strategy used in ventilated newborn swine with respiratory failure on cerebral blood flow (CBF) and tissue metabolism. Method Eighteen newborn swine were randomly (random number) divided into 3 groups (n = 6): PHC, normocapnia (NC) and normal control groups. In PHC (PaCO2 50～60 mmHg) and NC (PaCO2 35 ～ 45 mmHg) groups, newborn swine were ventilated for treating respiratory failure induced by meconium aspiration. CBF was measured by using colored microsphere tracking technique. Cerebral oxygen metabolism rate (CMRO2), cerebral glucose metabolism rate (CMRGlu), and cerebral lactate production (CLP) were measured. Results After ventilation for 6 hours and 12hours, CBF in NC group decreased more significantly than those did in control group, and CMRGlu and CLP increased more significantly than those did in control group. In NC group, CMRO2 decreased more prominently than it did in control group 12 hours later. The CBF/CMRGlu and CBF/CLP ratios in NC group were lower than those in control(P＜0.05). There was no significant difference in CBF/CMRO2 ratio between NC and control groups. After ventilation for 6 hours, CBF in PHC group was lower than those in control group. But after ventilation for 12hours, CBF in PHC group increased and there was no significant difference in CBF between PHC group and control group (P＞O.05). There were no significant differences in CMRGlu, CLP and CMRO2 between PHC group and control group. The CBF/CMRGlu and CBF/CLP ratios in PHC group were lower than those in control, but higher then those in NC group (P＜0.05). There was no significant difference in CBF/CMRO2 ratio between PHC and control groups. Conclusions The reduction of cerebral blood flow and the disturbance of CBF autoregulation disturbance occur in ventilated newborn swine with hypoxemia respiratory failure. PHC may attenuate the reduction in CBF and the disturbance of CBF autoregulation.
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We report a case of severe status asthmaticus in a 3-year-old boy who required mechanical ventilatory support. He initially presented with rapidly progressing respiratory distress and spontaneous air leaks. Although he was intubated and received mechanical ventilation, dynamic hyperinflation and air leaks were aggravated. We applied the volume control mode, providing sufficient tidal volume (10 ml/kg), a reduced respiratory rate (25/minute), and a prolonged expiratory time (1.8 seconds) to overcome dynamic hyperinflation. After allowing full expiration of trapped air, his over-expanded lung volumes were decreased and the air leaks resolved. He made a complete recovery without sequelae. Dynamic hyperinflation in asthmatic patients occurs from incomplete exhalation throughout narrowed airways. Controlled hypoventilation or permissive hypercapnia is an important lung-protective ventilator strategy and is beneficial in reducing dynamic hyperinflation. We suggest a controlled hypoventilation strategy with a prolonged expiratory time for patients in severe status asthmaticus with dynamic hyperinflation.
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Humans , Asthma , Exhalation , Hypercapnia , Hypoventilation , Lung , Positive-Pressure Respiration, Intrinsic , Child, Preschool , Respiration, Artificial , Respiratory Rate , Status Asthmaticus , Tidal Volume , Ventilators, MechanicalABSTRACT
Objective To observe the changes in inflammatory mediators in plasma in respiratory distress syndrome(RDS) of neonates received lung protective ventilation treatment. Methods Sixty newborn infants,diagnosed as RDS of neonatal and needed ventilator support, were recruited from the intensive care unit from May 2003 to May 2006. Infant with RDS were randomly divided into two groups. Both had 30 newborn infants. The infants in the experimental groups received lung protective ventilation treatment tidal volume:5-8 ml/kg,positive end-expiratory pressure (PEEP):0.51~0.98 kPa, and the control groups received large tidal volume ventilation (tidal volume:10-15 ml/kg,PEEP:0-0.29 kPa). The contents of TNF-?, interleukin-6 in plasma were measured. Results After those two therapies, the contents of tumor necrosis factor-?(TNF-?), interleukin-6 in plasma decreased obviously, especially after receiving lung protective ventilation treatment. Conclusions There are statistical differences in the amount of inflammatory mediators released between the experimental group under lung protective ventilation treatment and the control group received large tidal volume ventilation,and better effects are seen in RDS infants under lung protective ventilation treatment .
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BACKGROUND: A technique that improves the efficiency of alveolar ventilation should decrease the pressure required and reduce the potential for lung injury during mechanical ventilation. High PaCO2 can be permitted to lower airway pressures as in permissive hypercapnia (PH). Intratracheal pulmonary ventilation (ITPV) was developed to allow a decrease in physiological dead space during mechanical ventilation. We compared the effect of hybrid ventilation (HV) as a modification of ITPV with PH on the decrease of tidal volume and airway pressures in rabbits with acute respiratory failure. METHODS: Tracheostomy was performed in 7 rabbits ventilated under volume-controlled mode in the supine position. Arterial blood gas analysis, airway pressures, and dead space ventilation were measured at respiratory rate of 20/min as control values. Oleic acid (OA) of 0.06 ml/kg was injected to induce acute respiratory failure. Tidal volume (VT) was elevated to maintain PaCO2 in the normal range. The same parameters were measured as OA values. Then VT was reduced to the control level to allow PH. HV was initiated by inserting a reverse thrust catheter (RTC) into the endotracheal tube. HV consists of a pressure-controlled mode of mechanical ventilation and ITPV while flushing fresh gas continuously via the RTC. Respiratory parameters were compared under control, OA, PH and HV conditions. RESULTS: Oleic acid injection decreased PaO2 from 401+/-35 mmHg to 129+/-39 mmHg, increased VT from 42+/-5 ml to 52+/-10 ml, and increased VD/VT ratio from 0.65+/-0.07 to 0.71+/-0.07. During PH, the increase in PaCO2 was accompanied by the increase in VD/VT ratio from 0.71+/-0.07 to 0.79+/-0.03 and by the decrease of peak inspiratory pressure (PIP) from 19.4+/-4.0 cmH2O to 16.8+/-3.1 cmH2O. PaCO2 was lowered from 50+/-5 mmHg in PH to 39+/-5 mmHg in HV with a lower VT. VD/VT ratio in HV was as low as that in control. CONCLUSION: HV is an effective and easy-to-use ventilatory modality to reduce PaCO2 and airway pressures by the reduction in VD/VT ratio in acute respiratory failure model.
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Rabbits , Blood Gas Analysis , Catheters , Flushing , Hydrogen-Ion Concentration , Hypercapnia , Lung Injury , Oleic Acid , Pulmonary Ventilation , Reference Values , Respiration, Artificial , Respiratory Insufficiency , Respiratory Rate , Supine Position , Tidal Volume , Tracheostomy , VentilationABSTRACT
Congenital tracheal stenosis is a rare life-threatening obstruction in infancy and childhood. Symptoms are ranged from recurrent stridor and wheezing to severe respiratory compromise and hypercarbia. If the patient with tracheal stenosis, who has hypercarbia, is hyperventilated to maintain normocarbia, air is trapped in the lung and the risk of pulmonary barotrauma is increased. Cardiopulmonary-bypass is recommended for this patient to have corrective surgery. Permissive hypercapnia is proposed for the mechanical ventilation of patients with severe tracheal stenosis before cardiopulmonary-bypass.
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Humans , Barotrauma , Carbon Dioxide , Hypercapnia , Lung , Respiration, Artificial , Respiratory Sounds , Tracheal StenosisABSTRACT
The clinical complex of ARDS includes hypoxemia, hypercapnia, diffuse pulmonary infiltrates on chest radiograph, and depressed pulmonary compliance. Even with improved intensive care, the onset of severe disease with ARDS is associated with high mortality rate of 55% to 85% in an adult population. The etiology of ARDS remains uncertain, although increasing experimental evidence suggests that high inflation pressures may be involved in the pulmonary injury that is associated with ARDS. The use of low volume, pressure limited mechanical ventilation with permissive hypercapnia has been proposed to reduce the mortality rates associated with severe ARDS. Pressure-controlled ventilation has been proposed to recruit closed alveolar units and improve oxygenation through changing the inspiratory flow pattern from a square wave as used with volume-controlled ventilation to a rapidly exponentially decaying curve and through maintaining airway pressure at a constant level throughout the inspiratory phase. We present the case of a severe ARDS patient in whom a specific ventilatory management strategy of low peak inflation pressures and permissive hypercapnia appears to have favorably influenced survival and warrants further clinical evaluation.