Comparation of neurally adjusted ventilator assist and synchronized intermittent mandatory ventilation on respiratory function in premature infants with respiratory distress syndrome / 中国小儿急救医学

Objective To investigate the effect of neurally adjusted ventilator assist(NAVA) and synchronized intermittent mandatory ventilation(SIMV) on respiratory function in premature infants with respiratory distress syndrome.Methods A total of 54 preterm infants who were diagnosed neonatal respira-tory distress syndrome after birth and needed invasion mechanical ventilation in our hospital from Oct.2014 to Dec.2016 were given SIMV for 4 hours and NAVA mode ventilation for 4 hours,with a total of 4 cycles.The peak inspiratory pressure(PIP),tidal volume(TV),Compliance,respiratory rate(RR),Edi peak,Edi min, FiO2and mean airway pressure(MAP) were monitored every 30 minutes, and pressure of carbon dioxide (PaCO2)were monitored every 2 hours in different modes.Results The mean values of PIP[(19.5 ± 3.1) cmH2O,1 cmH2O=0.098 kPa],RR[(51.4 ± 7.9)breaths/min],Edi peak[(5.1 ± 3.2)μV],FiO2[(38.2 ± 12.9)%],MAP[(12.0 ± 0.8)cmH2O],PaCO2[(41.2 ± 9.3)mmHg,1 mmHg=0.133 kPa] and Edi min[(1.2 ± 1.4)μV] in NAVA mode were significantly lower than those in SIMV mode[(22.9 ± 3.4) cmH2O,(56.9 ± 8.3)breaths/min,(7.9 ± 4.9)μV,(39.9 ± 14.1)%,(13.2 ± 0.7)cmH2O,(47.1 ± 10.4)mmHg,(2.0 ± 1.7)μV,respectively](P<0.05).But the mean values of TV,Compliance in SIMV mode[(6.2 ± 1.0)ml/kg,(0.25 ± 0.33)ml/cmH2O,respectively] were significantly lower than those in the NAVA mode[(7.2 ± 0.9)ml/kg,(0.37 ± 0.21)ml/cmH2O,respectively](P<0.05).The downward trend of PIP,RR,Edi peak,FiO2,Edi min,MAP and upward trend of TV,Compliance were found during the first circle from NAVA mode to SIMV mode.The decrease and increase of above ventilator parameters were more obvious in NAVA mode compared with SIMV mode.Conclusion The respiratory muscle load is reduced, TV increases,and pulmonary compliance improves during NAVA ventilation.NAVA is better than SIMV in improving respiratory function of premature infants with respiratory distress syndrome. NAVA has lung protective effect.

A study on the application of proportional assisted ventilation in the treatment of neonatal respiratory failure / 中国新生儿科杂志

Objective To study the clinical application of proportional assisted ventilation (PAV) in the treatment of neonatal respiratory failure.Method From March 2011 to October 2013,a retrospective study was conducted on newborns receiving ventilation therapy for respiratory failure.The newborns were assigned into PAV group and synchronized intermittent mandatory ventilation (SIMV) group.Arterial blood pH 、partial pressure of arterial oxygen (PaO2)、partial pressure of arterial carbon dioxide (PaCO2) and oxygenation index (OI) were compared at the time before ventilation and 2 h,6 h,12 h,24 h after ventilation.The frequency of sedative usage and average time of ventilation between the two groups were compared.Result A total of 30 cases were enrolled in the PAV group and the SIMV group respectively.Before ventilation,no statically significant differences existed on blood pH[(7.13 ± 0.12)、(7.14 ±0.11)],PaO2[(41.1 ±8.9),(40.8±8.8) mmHg],PaCO2[(76.4±12.6),(73.2±13.5) mmHg]and OI between the two groups (P ＞ 0.05).2 h after ventilation,the blood pH [(7.25 ± 0.17)、(7.23 ± 0.15)],PaO2 [(51.0 ± 5.6)、(48.6 ± 5.3) mmHg] and OI were significantly improved,while PaCO2 [(66.3 ± 8.7)、(64.0 ± 7.5) mmHg] decreased.Comparing with data before ventilation,those parameters were statistically improved at each time point after ventilation (P ＜ 0.01).But no statistically differences existed between the two groups at the same time (P ＞ 0.05).Sedatives were used (2.3 ± 1.2)times/case in PAV group and (3.9 ± 2.2) in SIMV group,with statistically differences between the two groups (P ＜ 0.05).Average duration of ventilation were (5.1 ± 1.9) d in PAV group and (5.4 ± 2.1) d in SIMV group,with no statistically differences between the two groups (P ＞ 0.05).Conclusion PAV is very effective in treating the neonatal respiratory failure and worth spreading.

Application of BIPAP ventilation in children patients with severe hand foot and mouth disease complicating neurogenic pulmonary edema / 重庆医学

Objective To investigate the influence of two different mechanical ventilation modes of bi-level positive airway pressure ventilation(BIPAP)and synchronized intermittent ventilation (SIMV)on the respiratory function and clinical curative effect in children patients with severe hand foot and mouth disease(HFMD)complicating neurogenic pulmonary edema.Methods Thirty children patients with severe HFMD complicating neurogenic pulmonary edema receiving mechanical ventilation were divided into the SIMV group (control group)and BIPAP group (experimental group).The lung protective ventilation strategy was applied in both groups.After 30 min use of SIMV and positive end expiratory pressure (PEEP)ventilation,the experimental group changed to use the BIPAP ventilation mode,while the control group still used the initial parameters.The airway peak pressure,alveolar plat-form (Pplat)pressure,lung compliance,pH value,arterial blood CO2 partial pressure (PaCO2 )and oxygenation index (PaO2/FiO2 )at 0 h (baseline value),24,48,72 h after mechanical ventilation were monitored.Besides,the duration of mechanical ventila-tion,28 d mortality rate and the length of ICU stay were observed.Results Thirty children patients smoothly spent their acute re-spiratory failure period.One case in each group during the later period of treatment was transferred to the other hospital for contin-uous therapy.Among them the transferred case in the control group finally died due to give up treatment.The rest 28 cases all were cured and discharged from hospital.The 28 d mortality rates in the two groups were 6.67% and 0% respectively,with no statistical difference (P >0.05).Compared with the control group,the airway peak pressure,Pplat and PaCO2 after mechanical ventilation for 24,48,72 h in the experimental group were significantly decreased(P <0.05);the lung compliance and PaO2/ FiO2 improvement was significantly higher than that in the control group(P <0.05);meanwhile the duration of mechanical ventilation and the length of ICU stay in the experimental group were shorter than those in the control group (P <0.05).Conclusion The BIPAP mode used in the mechanical ventilation therapy of the children patients with severe HFMD complicating neurogenic pulmonary edema can pro-vide better effective ventilation,improve oxygenation and respiratory function,and shorten the duration of mechanical ventilation.

The effects of adaptive support ventilation on respiratory mechanics in elderly patients / 中华急诊医学杂志

Objective To explore the clinical application of adaptive support ventilation (ASV) in elderly patients with acute respiratory failure.Methods A total of 46 mechanically ventilated patients aged over 65 years with acute respiratory failure admitted from January 2013 to June 2015 were enrolled.Comparison between the ASV mode and synchronized intermittent mandatory ventilation (SIMV) mode was carried out in respects of the impacts of both modes on respiratory mechanics, hemodynamics, oxygen availability and comfort rate.Results Difference between ASV and SIMV in respiratory rate was [(20.84 ±4.04) vs.(24.50 ±4.60) cycles/min, t =4.04, P ＜0.05], in inspiratory resistance was [(13.24 ±4.76) vs.(16.54±5.25) cmH2O/ (L·s), t=3.16, P＜0.05], in mean airway pressure was [(13.58±2.58) vs.(16.63 ±1.57) mmHg, t =6.84, P＜0.05], in peak airway pressure was [(25.96 ± 3.69) vs.(27.87 ± 2.45) mmHg, t =2.92, P ＜ 0.05], and tidal volume was [(378.41 ± 85.61) vs.(341.52 ± 86.84) mL, t =2.05, P ＜ 0.05], and comfort rate of patients was increased in ASV mode.There were no statistically significant differences in arterial oxygen partial pressure, carbon dioxide partial pressure, lactate, heart rate, mean arterial pressure and central venous pressure between the two modes (PP ＞ 0.05).Conclusions Compared with the synchronized intermittent mandatory ventilation mode, the adaptive support ventilation mode can improve the respiratory mechanics and can increase the comfort rate in the elderly patients with mechanical ventilation.

The effects of different ventilator modes on cerebral tissue oxygen saturation in patients with bidirectional superior cavopulmonary connection.

Aims and Objectives: We used near‑infrared spectroscopy to document changes in cerebral tissue oxygen saturation (SctO2) in response to ventilation mode alterations after bidirectional Glenn (BDG; superior cavopulmonary connection) procedure. We also determined whether spontaneous ventilation have a beneficial effect on hemodynamic status, lactate and SctO2 when compared with other ventilation modes. Materials and Methods: 20 consecutive patients undergoing BDG were included. We measured SctO2 during three ventilator modes (intermittent positive‑pressure ventilation [IPPV]; synchronized intermittent mandatory ventilation [SIMV]; and continuous positive airway pressure + pressure support ventilation [CPAP + PSV]). We, also, measured mean airway pressure (AWP), arterial blood gases, lactate and systolic arterial pressures (SAP). Results: There was no change in SctO2 in IPPV and SIMV modes; the SctO2 measured during CPAP + PSV and after extubation increased significantly (60.5 ± 11, 61 ± 10, 65 ± 10, 66 ± 11 respectively) (P < 0.05). The differences in the SAP measured during IPPV and SIMV modes was insignificant; the SAP increased significantly during CPAP + PSV mode and after extubation compared with IPPV and SIMV (109 ± 11, 110 ± 12, 95 ± 17, 99 ± 13 mmHg, respectively) (P < 0.05). Mean AWP did not change during IPPV and SIMV modes, mean AWP decreased significantly during CPAP + PSV mode (14 ± 4, 14 ± 3, 10 ± 1 mmHg, respectively) (P < 0.01). Conclusions: The SctO2 was higher during CPAP + PSV ventilation and after extubation compared to IPPV and SIMV modes of ventilation. The mean AWP was lower during CPAP + PSV ventilation compared to IPPV and SIMV modes of ventilation.

Clinical value of targeted tidal volume in treatment of neonatal respiratory distress syndrome / 中华实用儿科临床杂志

Objective To explore the effect and complication of synchronized intermittent mandatory ventilation (SIMV) combined with pressure support ventilation (PSV) and targeted tidal volume (TTV) in treatment of neonatal respiratory distress syndrome(NRDS).Methods Fifty-three neonates with severe NRDS between Jan.2010 and Dec.2012 were randomly assigned to 2 groups according to the ventilation mode:SIMV + PSV + TTV group (n =27),and assist/control group (A/C group) (n =26).The oxygenation status,the durations of oxygen exposure and ventilation and the incidence of complications were observed.Results The oxygenation status arterial oxygen partial pressure/fraction of inspired oxygen (P/F),arterial oxygen partial pressure/alveolar O2 tension(a/APO2) in the SIMV + PSV +TTV group were significantly improved at 6 h after ventilation (t =9.393,4.856,all P ＜ 0.05) ;and compared with A/ C group,they were significantly improved at 6 h (t =6.132,2.805,all P ＜ 0.05),24 h (t =2.890,2.682,all P ＜0.05),72 h (t =3.804,4.053,all P ＜ 0.05) after ventilation in the SIMV + PSV + TTV group.The incidences of air leak syndrome and ventilation-associated pneumonia(VAP) were lower in the SIMV + PSV + TTV group than those in the A/C group(t =3.908,4.178,all P ＜ 0.05).There were no significant differences in the mortality between the two groups (t =0.534,P ＞ 0.05).Conclusions Compared with A/C,SIMV + PSV + TTV can improve the oxygenation status more quickly,and decrease the incidences of air leak syndrome and VAP in neonates with severe RDS.

A unilateral large bronchopleural fistula caused by rupture of bulla with coexisting bilateral giant bullae: A case report

A patient with a large bronchopleural fistula presents several intraoperative challenges for the anesthesiologist, particularly if bullae coexist bilaterally. Ideally, a double lumen tube is inserted while the patient is conscious or breathing spontaneously under general anesthesia to prevent possible tension pneumothorax in the contralateral lung due to positive-pressure ventilation and the possibility of inadequate ventilation due to an air leak from the fistula. However, we inserted a single lumen tube instead of a double lumen tube, because this patient had multiple giant bullae bilaterally and the contralateral lung tissue was almost completely compressed and destroyed. We report the use of a single lumen tube under volatile general anesthesia with synchronized intermittent mandatory ventilation with small tidal volume. In addition, we used permissive hypercapnia to further minimize barotraumas. Due to permissive hypercapnia, there were no cardiovascular consequences.

Three kinds of mechanical ventilations for treating neonatal respiratory distress syndrome / 中华实用儿科临床杂志

Objective To contrast the curative effects of proportional assist ventilation (PAV) and high frequency oscillatory ventilation(HFOV) and synchronized intermittent mandatory ventilation(SIMV) on treatment of neonatal respiratory distress syndrome(NRDS).Methods A retrospective study was carried out based on clinical data of 161 neonates.The research subjects were the neonates who had been hospitalized from May 2008 to May 2012 in Jiangmen Central Hospital and received one of the mechanical ventilation methods.The subjects were divided into 3 groups according to used mechanical ventilation mode they received,and their curative effect was compared.Results Fortythree cases in PAV group were treated by PAV,58 cases in HFOV group received HFOV,and 60 cases in SIMV group received SIMV.In comparison with sex ratio,gestational age of birth,birth weight,dose of poractant alfa injection there was no differece among 3 groups(all P ＞0.05).The number of effective cases in PAV group,HFOV group and SIMV group was 37 cases,57 cases,52 cases,respectively;the invalid cases including 6 cases,1 case,8 cases in 3 groups,respectively.Among the 3 groups,the curative effect was significantly different(x2 =6.197,P =0.045),curative effect of PAV group was not different from that of SIMV group(x2 =0.008,P =0.928),curative effect of HFOV group was better than that of PAV group and SIMV group(x2 =3.986,P =0.046 ;x2 =4.114,P =0.043).Conclusion The curative effect of HFOV for neonatal respiratory distress syndrome was better,which could be recommended.

Comparação entre ventilação mandatória intermitente e ventilação mandatória intermitente sincronizada com pressão de suporte em crianças / Comparison between intermittent mandatory ventilation and synchronized intermittent mandatory ventilation with pressure support in children

OBJETIVO: Comparar a ventilação mandatória intermitente (IMV) com a ventilação mandatória intermitente sincronizada com pressão de suporte (SIMV+PS) quanto à duração da ventilação mecânica, desmame e tempo de internação na unidade de terapia intensiva pediátrica (UTIP). MÉTODOS: Estudo clínico randomizado que incluiu crianças entre 28 dias e 4 anos de idade, admitidas na UTIP no período correspondente entre 10/2005 e 06/2007, que receberam ventilação mecânica (VM) por mais de 48 horas. Os pacientes foram alocados, por meio de sorteio, em dois grupos: grupo IMV (GIMV; n = 35) e grupo SIMV+PS (GSIMV; n = 35). Foram excluídas crianças traqueostomizadas e com insuficiência respiratória crônica. Dados relativos à oxigenação e ventilação foram anotados na admissão e no início do desmame. RESULTADOS: Os grupos não diferiram estatisticamente quanto à idade, sexo, indicação da VM, escore PRISM, escala de Comfort, uso de sedativos e parâmetros de ventilação e oxigenação. A mediana da duração da VM foi de 5 dias para ambos os grupos (p = 0,120). Também não houve diferença estatística quanto à duração do desmame [GIMV: 1 dia (1-6) versus GSIMV: 1 dia (1-6); p = 0,262] e tempo de internação [GIMV: 8 dias (2-22) versus GSIMV: 6 dias (3-20); p = 0,113]. CONCLUSÃO: Não houve diferença estatisticamente significativa entre IMV e SIMV+PS quanto à duração da VM/desmame e tempo de internação nas crianças avaliadas. ClinicalTrials.govID: NCT00549809.

OBJECTIVE: To compare intermittent mandatory ventilation (IMV) with synchronized intermittent mandatory ventilation plus pressure support (SIMV+PS) in terms of time on mechanical ventilation, duration of weaning and length of stay in a pediatric intensive care unit (PICU). METHODS: This was a randomized clinical trial that enrolled children aged 28 days to 4 years who were admitted to a PICU between October of 2005 and June of 2007 and put on mechanical ventilation (MV) for more than 48 hours. These patients were allocated to one of two groups by drawing lots: IMV group (IMVG; n = 35) and SIMV+PS group (SIMVG; n = 35). Children were excluded if they had undergone tracheotomy or had chronic respiratory diseases. Data on oxygenation and ventilation were recorded at admission and at the start of weaning. RESULTS: There were no statistical differences between the groups in terms of age, sex, indication for MV, PRISM score, Comfort scale, use of sedatives or ventilation and oxygenation parameters. The median time on MV was 5 days for both groups (p = 0.120). There were also no statistical differences between the two groups for duration of weaning [IMVG: 1 day (1-6) vs. SIMVG: 1 day (1-6); p = 0.262] or length of hospital stay [IMVG: 8 days (2-22) vs. SIMVG: 6 days (3-20); p = 0.113]. CONCLUSION: Among the children studied here, there was no statistically significant difference between IMV and SIMV+PS in terms of time on MV, duration of weaning or time spent in the PICU. ClinicalTrials.govID: NCT00549809.

Comparison of pressure support ventilation or synchronized intermittent mandatory ventilation for respiratory failure after cervical spinal cord injured ZHOU Hao, ZHAO Hai-ping / 中国康复理论与实践

@#ObjectiveTo observe the difference between pressure support ventilation(PSV) and synchronized intermittent mandatory ventilation(SIMV) in cervical spinal cord injury patients with respiratory failure.MethodsThe blood gas analysis,respiratory rate,heart rate,blood pressure and subjective feelings were observed in the same patient under different ventilation(PSV or SIMV).ResultsThere was no significant difference in blood pressure when patients underwent PSV and SIMV.Otherwise,There was significant difference in respiratory rate,heart rate,pH,PaO2,PaCO2 and subjective feelings when patients underwent PSV and SIMV,which showed that of PSV were better.ConclusionThe effect of PSV was better than that of SIMV on respiratory failure after cervical spinal cord injury.

The Effect of Pressure Support on Respiratory Mechanics in CPAP and SIMV / 결핵

BACKGROUND: Pressure support(PS) is becomimg a widely accepted method of mechanical ventilation either for total unloading or for partial unloading of respiratory muscle. The aim of the study was to find out if PS exert different effects on respiratory mechanics in synchronized intermittent mandatory ventilation(SIMV) and continuous positive airway pressure (CPAP) modes. METHODS: 5, 10 and 15 cm H2O of PS were sequentially applied in 14 patients(69+/-12 yrs, M:F=9:5) and respiratory rate (RR), tidal volume(VT), work of breathing(WOB), pressure time product(PTP), P(0.1), and T(1)/T(TOT) were measured using the CP-100 pulmonary monitor(Bicore, USA) in SIMV and CPAP modes respectively. RESULTS: 1) Common effects of PS on respiratory mechanics in both CPAP and SIMV modes As the level of PS was increased(0, 5, 10, 15 cm H2O), VT was increased in CPAP mode(0.28+/-0.09, 0.29+/-0.09, 0.31+/-0.11, 0.34+/-0.12 L, respectively, p=0.001), and also in SIMV mode(0.31+/-0.15, 0.32+/-0.09, 0.34+/-0.16, 0.36+/-0.15 L, respectively, p=0.0215). WOB was decreased in CPAP mode(1.40+/-1.02, 1.01+/-0.80, 0.80+/-0.85, 0.68+/-0.76 joule/L, respectively, p=0.0001), and in SIMV mode(0.97+/-0.77, 0.76+/-0.64, 0.57+/-0.55, 0.49+/-0.49 joule/L, respectively, p=0.0001). PTP was also decreased in CPAP mode(300+/-216, 217+/-165, 179+/-187, 122+/-114cm H2O * sec/min, respectively, p=0.0001), and in SIMV mode(218+/-181, 178+/-157, 130+/-147, 108+/-129cm H2O.sec/min, respectively, p=0.0017). 2) Different effects of PS on respiratory mechanics in CPAP and SIMV modes By application of PS (0, 5, 10, 15 cm H2O), RR was not changed in CPAP mode(27.9+/-6.7, 30.0+/-6.6, 26.1+/-9.1, 27.5+/-5.7/min, respectively, p=0.505), but it was decreased in SIMV mode (27.4+/-5.1, 27.8+/-6.5, 27.6+/-6.2, 25.1+/-5.4/min, respectively, p=0.0001). P(0.1) was reduced in CPAP mode(6.2+/-3.5, 4.8+/-2.8, 4.8+/-3.8, 3.9+/-2.5 cm H2O, respectively, p=0.0061), but not in SIMV mode(4.3+/-2.1, 4.0+/-1.8, 3.5+/-1.6, 3.5+/-1.9 cm H2O, respectively, p=0.054). T(1)/T(TOT) was decreased in CPAP mode(0.40+/-0.05, 0.39+/-0.04, 0.37+/-0.04, 0.35+/-0.04, respectively, p=0.0004), but not in SIMV mode(0.40+/-0.08, 0.35+/-0.07, 0.38+/-0.10, 0.37+/-0.10, respectively, p=0.287). 3) Comparison of respiratory mechanics between CPAP+PS and SIMV alone at same tidal volume. The tidal volume in CPAP+PS 10 cm H2O was comparable to that of SIMV alone. Under this condition, the RR(26.1+/-9.1, 27.4+/-5.1/min, respectively, p=0.516), WOB(0.80+/-0.85, 0.97+0.77 joule/L, respectively, p=0.485), P0.1(3.9+/-2.5, 4.3+/-2.1 cm H2O, respectively, p=0.481) were not different between the two methods, but PTP(179+/-187, 218+/-181 cmH2O.sec/min, respectively, p=0.042) and T(1)/T(TOT)(0.37+/-0.04, 0.40+/-0.08, respectively, p=0.026) were significantly lower in CPAP+PS than in SIMV alone. CONCLUSION: PS up to 15 cm H2O increased tidal volume, decreased work of breathing and pressure time product in both SIMV and CPAP modes. PS decreased respiration rate in SIMV mode but not in CPAP mode, while it reduced central respiratory drive(P(0.1)) and shortened duty cycle (T(1)/T(TOT)) in CPAP mode but not in SIMV mode. By 10 cm H2O of PS in CPAP mode, same tidal volume was obtained as in SIMV mode, and both methods were comparable in respect to RR, WOB, P(0.1), but CPAP+PS was superior in respect to the efficiency of the respiratory muscle work (PTP) and duty cycle(T(1)/T(TOT)).

Respiratory Parameters of Pressure Support Ventilation and Synchronized Intermittent Mandatory Ventilation during the Weaning Process / 대한마취과학회지

SIMV (synchronized intermittent mandatory ventilation) is a volume assisted mode which a patient inspiratory demand results in a clinician-controlled tidal volume and flow rate. However, PSV (pressure support ventilation) has the ability to augment spontaneous breaths with a variable amount of inspiratory positive pressure with a clinician-selected level of inspiratory airway pressure. To compare the effects of SIMV and PSV on respiratory function, experiments were performed on 12 stable patients during the weaning process and tidal volume, airway pressure, arterial blood gas tensions, blood pressure, and heart rates were measured during SIMV, and after 2 mins after removal of mechanical ventilation support. The same measurement as SIMV (except mandatory respiratory rates) were performed during PSV. The PSV level was reduced in the 5 cm2O step every 10-15 mins. The results of respiratory parameters and hemodynamic data showed that tidal volume, blood pressure, heart rates, and arterial blood gas tensions were similar, but there were significantly lower ventilatory rates, lower peak airway pressure and lower mean airway pressure during PSVmax than SlMV, and PSV resulted in improved patient comfort. It was concluded that PSV could be used to unload the patients ventilatory muscles and provide an appropriate level of mechanical ventilation support similar to SIMV weaning approaches.