Application of extracorporeal membrane oxygenation in children with acute respiratory distress syndrome / 中国当代儿科杂志

The children with acute respiratory distress syndrome (ARDS) usually require ventilatory support treatment. At present, lung protective ventilation strategy is recommended for the treatment of ARDS. Extracorporeal membrane oxygenation (ECMO) can improve oxygenation and remove carbon dioxide by extracorporeal circuit, and can partially or completely take over cardiopulmonary function. ECMO support showed many advantages in treating severe ARDS, such as reducing ventilator-induced lung injury and correcting hypoxemia. Over the past few years, there has been an increase in the use of ECMO for ARDS in children. This paper reviews the applications of ECMO for the treatment of ARDS in children.

Changes of the hemodynamics and extravascular lung water after different-volume fluid resuscitation in a piglet model of endotoxic shock / 中华儿科杂志

<p><b>OBJECTIVE</b>Practice recommendations have evolved, and consensus now exists among leading organizations such as the American College of Critical Care Medicine (ACCM) and Surviving Sepsis Campaign that fluid infusion is best initiated with boluses of 20 ml/kg, commonly requires 40-60 ml/kg but can be as much as 200 ml/kg if the liver is not enlarged and/or rales are not heard. The present study aimed to investigate and compare the changes of the hemodynamics and extravascular lung water after higher volume fluid resuscitation in a piglet model of endotoxic shock.</p><p><b>METHOD</b>Twenty piglets were used for establishing animal models of endotoxic shock by intravenous infusing lipopolysaccharide (LPS). The experimental animals were divided into three groups according to the volume infused during the resuscitation. The three groups received different volume of saline in less than an hour after endotoxic shock. By the PiCCO plus system, we investigated the changes of hemodynamics and extravascular lung water.</p><p><b>RESULT</b>After fluid resuscitation, global end diastolic volume inder, (GEDI) and intrathoracic blood volume index, (ITBI) markedly increased in the group of 80 ml/kg and 120 ml/kg, but there was no change in the group of 40 ml/kg. GEDI: Fifteen min after fluid resuscitation R1 was (261 ± 64) ml/m(2), R2 (457 ± 124) ml/m(2), R3 (413 ± 148) ml/m(2), 4 h R1 (251 ± 68) ml/m(2), R2 (422 ± 70) ml/m(2), R3 (470 ± 160) ml/m(2); ITBI: Fifteen min after fluid resuscitation R1 was (335 ± 69) ml/m(2), R2 (550 ± 179) ml/m(2), R3 (520 ± 183) ml/m(2), 4 h R1 (314 ± 84) ml/m(2), R2 (534 ± 96) ml/m(2), R3 (594 ± 200) ml/m(2) (R1 vs. R2 vs. R3, F = 26.373, P < 0.05; R1 vs. R2, R1 vs. R3, P < 0.05; R2 vs. R3, P > 0.05). CI of all three groups significantly decreased when the models were established. After fluid resuscitation, the base level was maintained in the group of 80 ml/kg and 120 ml/kg, but it was under the basic level in the group of 40 ml/kg.Fifteen min after fluid resuscitation R1 was (4.5 ± 0.7) L/(min·m(2)), R2 (6.4 ± 2.2) L/(min·m(2)), R3 (5.5 ± 0.7) L/(min·m(2)), 4 h R1 (4.1 ± 1.0) L/(min·m(2)), R2 (5.2 ± 0.9) L/(min·m(2)), R3 (5.1 ± 0.8) L/(min·m(2)). There was no significant difference in CI between these two groups (P > 0.05).ELWI of the group of 80 ml/kg and 120 ml/kg were still higher than that of the group of 40 ml/kg, 15 min after fluid resuscitation R1 was (19.2 ± 8.6) ml/kg, R2 (29.2 ± 5.5) ml/kg, R3 (23.4 ± 8.2) ml/kg, 4 h R1 (18.3 ± 6.5) ml/kg, R2 (23.8 ± 2.6) ml/kg, R3 (21.4 ± 3.9) ml/kg, but there was no significant difference in ELWI among the groups (P > 0.05).</p><p><b>CONCLUSION</b>Resuscitation with higher volume of fluid infusion in the early stage of endotoxic shock was more efficient to increase the preload and maintain the cardiac output at the baseline level, and might reduce the need for vasoactive agents. Meanwhile, resuscitation with higher volume of fluid in the early stage of endotoxic shock did not sharply increase the extravascular lung water.</p>

Effects of high volume hemofiltration on hemodynamics and oxygen metabolism at early stage of septic shock in piglet models / 中华儿科杂志

<p><b>OBJECTIVE</b>To observe the effects of hemofiltration at early stage of septic shock with different ultrafiltration doses, including hemodynamics, oxygen metabolism, inflammatory mediator in piglet models, and to evaluate the therapeutic effects of HVHF.</p><p><b>METHOD</b>The 18 healthy young piglets (Shanghai species) were divided randomly into three groups:control group (n = 6), conventional volume hemofiltration (CVVH) group [n = 6, ultrafiltration volume = 30 ml/(kg·h)] and high volume hemofiltration (HVHF) group [n = 6, ultrafiltration volume = 50 ml/(kg·h)], the animal model of septic shock was established by injection of lipopolysaccharide (LPS) (150 µg/kg) O111: B4. During the experiment, the following observations were carried out for all groups:1) Changes of hemodynamics [heart rate (HR), mean arterial pressure (MABP), cardiac output (CO), systemic vascular resistance index (SVRI), intrathoracic blood volume (ITBV)] and oxygen metabolism [oxygen delivery (DO2), oxygen consumption (VO2), oxygen extraction rate (O2ER) ] at the time of B0h, 0 h, 2 h, 4 h and 6 h.2) changes of TNF-α, IL-6, IL-10 in plasma at different time points (B0h, 0 h, 2 h, 4 h, 6 h).</p><p><b>RESULT</b>Significant difference in circulatory parameters, inflammatory mediators in plasma were found at B0h and 0 h among three groups; the CO in two treatment groups were higher than that in control group at 4 h, 6 h after model establishment (P < 0.05), and SVRI in HVHF groups were higher than that in other two groups at 4 h, 6 h after model was established (P < 0.05). The MABP in HVHF group [4 h (82 ± 17) mm Hg, 6 h (80 ± 12) mm Hg](1 mm Hg = 0.133 kPa) were higher than that in CVVH group at 4 h [(67 ± 12) mm Hg], 6 h [(69 ± 14) mm Hg] after model was established (P < 0.05). The levels of IL-6, IL-10, TNF-α in two treatment groups were lower than that in control group at 4 h and 6 h after model was established (P < 0.05), and the IL-6 [(281 ± 51) pg/ml], TNF-α [(67 ± 13) pg/ml] level in HVHF group was lower than that in CVVH group [IL-6(281 ± 51) pg/ml, TNF-α (67 ± 13) pg/ml] at 6 h (P < 0.05). The DO2 and VO2 in two treatment groups were higher than that in control group at 4 h, 6 h (P < 0.05), the O2ER in HVHF group were higher than that in CVVH group at 4 h (44% ± 3% vs. 33% ± 4%), 6 h (43% ± 5% vs. 31% ± 3%, P < 0.05).</p><p><b>CONCLUSION</b>High volume hemofiltration (HVHF) at early stage of septic shock piglet models was more effective in improving hemodynamics, oxygen metabolism than conventional CVVH. And HVHF eliminated blood inflammatory mediators more effectively than conventional CVVH.</p>

Mortality and morbidity of acute hypoxemic respiratory failure and acute respiratory distress syndrome in infants and young children / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Acute hypoxemic respiratory failure (AHRF) often develops acute respiratory distress syndrome (ARDS), and its incidence and mortalities in critically ill pediatric patients in China were 2% and 40% respectively. This study aimed at prospectively investigating incidence, causes, mortality and its risk factors, and any relationship to initial tidal volume (V(T)) levels of mechanical ventilation, in children £5 years of age with AHRF and ARDS.</p><p><b>METHODS</b>In 12 consecutive months in 23 pediatric intensive care units (PICU), AHRF and ARDS were identified in those requiring > 12 hour intratracheal mechanical ventilation and followed up for 90 days or until death or discharge. ARDS was diagnosed according to the American-European Consensus definitions. The mortality and ventilation free days (VFD) were measured as the primary outcome, and major complications, initial disease severity, and burden were measured as the secondary outcome.</p><p><b>RESULTS</b>In 13 491 PICU admissions, there were 439 AHRF, of which 345 (78.6%) developed ARDS, resulting in incidences of 3.3% and 2.6%, and corresponding mortalities of 30.3% and 32.8% respectively along with 8.2 and 6.7 times of relative risk of death in those with pneumonia (62.9%) and sepsis (33.7%) as major underlying diseases respectively. No association was found in V(T) levels during the first 7 days with mortality, nor for V(T) at levels < 6, 6 - 8, 8 - 10, and > 10 ml/kg in the first 3 days with mortality or length of VFD. By binary Logistic regression analyses, higher pediatric risk of mortality score III, higher initial oxygenation index, and age < 1 year were associated with higher mortality or shorter VFD in AHRF.</p><p><b>CONCLUSIONS</b>The incidence and mortalities of AHRF and ARDS in children £5 years were similar to or lower than the previously reported rates (in age up to 15 years), associated with initial disease severity and other confounders, but causal relationship for the initial V(T) levels as the independent factor to the major outcome was not found.</p>

Recruitment maneuver in the treatment of young piglets with acute lung injury / 中国当代儿科杂志

<p><b>OBJECTIVE</b>To study the feasibility, efficiency and any benefits of recruitment maneuver (RM) in the facilitation of lung repair during recovery from ALI in acute lung injury (ALI) model of young piglets.</p><p><b>METHODS</b>The piglet model of ALI was established by an intravenous injection of lipopolysaccharide (LPS). Twelve ALI piglets were randomly divided into two groups: conventional ventilation (CON) and RM with low tidal volume. Arterial blood gas, dynamic lung compliance (Cdyn) and systematic hemodynamics were monitored during the treatment. TGF-β1 levels in bronchoalveolar lavage fluid (BALF) and plasma were measured. The mRNA expression of TGF-β1 in the lungs was assessed by real time PCR. Lung tissue was examined for morphological changes.</p><p><b>RESULTS</b>No significant difference was observed in cardiac output and peripheral vascular resistance (PVR) between the two groups. The extravascular lung water index (ELWI) from 6 hrs after ALI inducement and the pulmonary vascular permeability index (PVPI) 8 hrs after ALI inducement in the RM group decreased significantly compared with the CON group. Cdyn in the RM group increased quickly 1 hr after ALI inducement, and there was a significant difference between the two groups (P<0.05). P/F (ratio of PaO2 to FiO2) in the RM group was significantly higher than in the CON group from 2 hrs after ALI inducement (P<0.05). Alveolar-to-arterial oxygen difference in the RM group was obviously lower compared with the CON group from 2 hrs after ALI inducement (P<0.05). The levels of TGF-β1 in plasma and BALF and the mRNA expression of TGF-β1 in the lung tissue were lower than in the CON group. Volume density of alveolar aeration in the RM group was significantly higher than in the CON group, and the injury score in the RM group was lower (P<0.05).</p><p><b>CONCLUSIONS</b>RM can improve gas exchange and Cdyn in the treatment of piglets with ALI. RM is a safe and effective approach to alveolar recruitment and can alleviate ventilation induced lung injury.</p>

Clinical analysis of recruitment maneuver with low tidal volume in the treatment of 15 children with acute lung injury / 中华儿科杂志

<p><b>OBJECTIVE</b>To determine the effects and feasibility of recruitment maneuver (RM) on children with acute lung injury (ALI), and to establish a more reasonable ventilation strategy in the treatment of pediatric ALI.</p><p><b>METHOD</b>A prospective physiologic study was conducted in the Pediatric Intensive Care Unit (PICU). Fifteen consecutive eligible pediatric patients with ALI according to the 1994 AECC definition were enrolled in this study. The children received the ventilation of RM with low tidal volume. The clinician administered RM was performed at 30 cm H2O continuous positive airway pressure (CPAP) for 30 seconds. RMs were conducted once every eight hours for five days. Data on gas exchange, lung mechanics and hemodynamics from pre-RM to post-RM (at 5, 15, 30 and 60 min) was recorded at the first, third and fifth day. To monitor the pathogenic conditions of children, the radiographic examination was rechecked for every child within one week. At last, we documented the mortality and the length of ventilation of every patient.</p><p><b>RESULT</b>On the first, third and fifth day, the P/F ratio of the patients was 243.8 mm Hg, 281.8 mm Hg and 309.9 mm Hg respectively, and significant improvements in oxygenation were demonstrated post-RM compared to pre-RM (P < 0.01). Cdyn [0.762 ml/(cm H2O×kg), 0.835 (ml/cm H2O×;kg), 0.928 ml/(cm H2O×kg)] before RMs also showed increase in the children on the first, third and fifth day (P < 0.01). Though there were some changes in blood pressure and heart rate following RM, no statistically significant changes were found during the course of RM. During the entire study of 5 days, all the 11 subjects whose chest radiograph showed infiltration had improvements, the length of ventilation was (10.15 ± 4.3) d.</p><p><b>CONCLUSION</b>RM can significantly improve the oxygenation and attenuate the deterioration in pulmonary function in treatment for pediatric ALI and improve the lung compliance. It is safe and feasible.</p>

Effect of continuous veno-venous hemodiafiltration on hemodynamics of piglets with endotoxin-induced acute lung injury / 中华儿科杂志

<p><b>OBJECTIVE</b>To investigate the effect of continuous veno-venous hemodiafiltration (CVVHDF) on endotoxin-induced acute lung injury (ALI) of piglets.</p><p><b>METHODS</b>Eighteen piglets were randomly divided into three groups: control group (n = 6); heparin group (n = 6) and CVVHDF treatment group (n = 6). All the animals were anesthetized by muscle injection of ketamine (30 mg/kg), then placed in supine position, received continuous intravenous infusion of ketamine with the rate of 10 mg/(kgxh). After placing a 4.5 cm (inner diameter) tracheal tube via tracheostoma, controlled mechanical ventilation was established using the assisted-controlled ventilation option of the NEWPORT 200. Respiratory rate at 30 breath/min; PIP at 10 cm H2O (1 cm H2O = 0.098 kPa); PEEP at 2 cm H2O and fraction of inspired oxygen at 0.3. A vein catheter was placed into right vena jugularis interna to administer a Ringer's solution. Initially, at a rate of 10 ml/kg, followed by a rate of 15 ml/kg when the mean arterial blood pressure was below 70 mm Hg (1 mm Hg = 0.133 kPa), the rate of 20 ml/kg was used when the mean arterial blood pressure was below 60 mm Hg. An 8Fr double-lumen catheter was inserted into left femoral vein and served as the pathway for CVVHDF. A Pulsiocath Pcco catheter was positioned into left femoral artery to monitor the circulatory parameters. All catheters were flushed with heparinized saline to prevent clotting. Then all the animals were given intravenous infusion of 150 microg/kg endotoxin within 30 minutes to induce ALI. When the oxygenation index < 300 and pulmonary compliance < 30% of the baseline, the animals of heparin group received heparin infusion to maintain blood active coagulation time (ACT) 180 - 250 s, the animals of treatment group received CVVHDF with the blood flow of 50 ml/min, replacement rate of 300 ml/h, dialysis rate of 600 ml/h and the ultrafiltrate rate of 350 ml/h for six hours, heparin infusion to keep blood ACT 180 - 250 s. The circulatory parameters: heart rate (HR), mean arterial blood pressure (MABP), central venous pressure (CVP), pulse contour cardiac output index (PCCI); systemic venous resistance index (SVRI), cardiac function index (CFI), external venous lung water index (EVLWI), left ventricular contractile index (dPmx); respiratory parameters: respiratory rate (RR), pulmonary compliance (Cdyn) were monitored; arterial blood gas analysis was performed and oxygenation index (PaO2/FiO2) was calculated. All the parameters were recorded at baseline (B), onset of ALI (A 0 h), two hours (A 2 h), four hours (A 4 h), six hours (A 6 h) after ALI.</p><p><b>RESULTS</b>No significant difference in circulatory parameters, respiratory parameters and blood gas analysis were found at B and A 0 h among the three groups. When the ALI occurred, PaO2/FiO2, Cdyn, MABP and PCCI of the three groups decreased; HR, RR, EVLWI, SVRI increased. After four hours of ALI, the RR, EVLWI, SVRI, CFI and dPmx of treatment group were improved, the differences were significant compared with the other two groups (P < 0.05). After six hours of ALI, the HR, PCCI, MABP, PaO2/FiO2 and Cdyn of treatment group were significantly improved, compared with control group and heparin group (P < 0.05). There were no significant differences in any of the parameters between control group and heparin group. The difference in CVP among three groups was not significant.</p><p><b>CONCLUSION</b>CVVHDF has a good effect on hemodynamics of the endotoxin-induced ALI of the piglets.</p>

Therapeutic effect of continuous veno-venous hemodiafiltration on systemic inflammatory response syndrome induced by cecum perforate peritonitis in piglets / 中国当代儿科杂志

<p><b>OBJECTIVE</b>Most of the therapeutic strategies for systemic inflammatory response syndrome (SIRS) is not effective. This study was to investigate the effect of continuous veno-venous hemodiafiltration (CVVHDF) on SIRS induced by cecum perforate peritonitis in piglets.</p><p><b>METHODS</b>Twelve piglets (weighing 7-9 kg) were randomly divided into two groups: control and CVVHDF (n=6). The piglets of both groups were subjected to a cecum puncture to induce peritonitis which caused SIRS. After SIRS occurred the piglets of the CVVHDF group immediately received the CVVHDF therapy for 6 hrs, with a blood flow rate of 20 mL/min, a replacement rate of 300 mL/h, and a dialysis rate of 600 mL/h. The heart rate (HR), mean artery blood pressure (MABP), respiratory rate (RR), arterial blood gas analysis and blood cells count were measured and recorded at baseline and onset of SIRS, and 2, 4 and 6 hrs after SIRS occurred.</p><p><b>RESULTS</b>When SIRS occurred, the HR and RR increased and the MABP, artery oxygen pressure (PaO2) and the count of white cells decreased in both groups. The HR of the CVVHDF group decreased significantly at 2 hrs (P < 0.05) and remained lower until 6 hrs after CVVHDF therapy (P < 0.01) compared with that of the control group. The RR of the CVVHDF group was significantly lower than that of the control group 6 hrs after CVVHDF therapy (P < 0.05). The MABP of the CVVHDF group increased significantly 4 and 6 hrs after therapy compared with that of the control group (P < 0.01, P < 0.05 respectively). There were no significant differences in temperature, PaO2 and blood cells count between the two groups during the experiment.</p><p><b>CONCLUSIONS</b>CVVHDF has a positive effect on hemodynamics in piglets with SIRS induced by cecum perforate peritonitis.</p>

Continuous blood purification therapy in 22 children with sepsis / 中华儿科杂志

<p><b>OBJECTIVE</b>Since continuous blood purification (CBP) has the effects of eliminating inflammatory mediators and improving organs function, CBP had been applied to treat non-renal diseases for nearly 10 years, but few studies have been conducted in children with sepsis and multiorgan dysfunction syndrome (MODS), especially in China. The present study aimed to evaluate the clinical effect of CBP in treatment of children with severe sepsis and MODS.</p><p><b>METHODS</b>Twenty-two children with severe sepsis and MODS admitted to our PICU from Aug. 2003 to Aug. 2005 were treated with continuous veno-venous hemodialysis filtration. Their heart rate, arterial blood pressure, doses of vasoactive agents, spontaneous respiratory rate, PO2/FiO2 and prognosis were investigated.</p><p><b>RESULTS</b>Catheterization and CBP were carried out in all the 22 children. Continuous vein-vein hemodialysis filtration (CVVHDF) and pre-dilution were chosen. The duration of CBP was (64.4 +/- 34.5) h. All the children had tachycardia before CBP and the heart rate fell gradually to 45 +/- 13 bpm 4 h after CBP. Blood pressure (BP) was stable in 7 children without shock during CBP. Ten children with early shock could maintain normal BP during CBP, but the doses of vasoactive agents were tapered 1 to 5 h after beginning of CBP and use of these agents was discontinued at 2 to 8 h. BP was elevated by (25.2 +/- 10.7) mmHg (1 mmHg = 0.133 kPa) in 5 refractorily shocked children 4 h after CBP and returned to normal level 8 h later. The doses of the vasoactive drugs were reduced at 2 to 8 h and ended 4 to 16 h later, which was longer than that of children with early stage shock. The accelerated spontaneous respiratory rate was slowed down by 7 +/- 4 per minute 4 h later, PO2/FiO2 rose from (177.7 +/- 53.1) mmHg before CBP to (341.0 +/- 60.2) mmHg 4 h after CBP in children with respiratory failure and reached the normal value (5.3 +/- 2.1) h later. FiO2 declined to less than 50%. Pediatric critical illness score was 62.2 +/- 7.4 on admission and elevated to (86.6 +/- 9.0) 24 h later, which was a significant elevation as compared to that of children with sepsis who were not treated with CBP seen between Aug. 2001 and July 2003. The survival rate was 72.7% after CBP and the effective rate of the treatment was 90.9%, but was 36% in children who were not treated with CVVHDF.</p><p><b>CONCLUSION</b>CBP can effectively improve the vital organ's function of children with sepsis and MODS and raise their survival rate. Replacement fluid of modified Ports formula was useful for stability of serum potassium and sodium, but resulted in elevation of serum glucose, calcium, and osmolarity. The application of CBP in children with sepsis can lead to slight drop of blood pressure at the beginning and to bleeding during CBP.</p>

Application of Low Tidal Volume Ventilation in Children with Acute Respiratory Failure / 实用儿科临床杂志

Objective To study the therapeutic and protective effect of low tidal volume(LTV) ventilation in children with acute respiratory failure.Methods Forty-eight patients with respiratory failure were enrolled in our study.The patients were suffered from severe infection,trauma or after major operation.Besides general treatments,they were all given ventilation with LTV.Blood gas,ventilation parameters and complications related to ventilation were also measured.Results No significant difference was found between the patients with high tidal volume(HTV) and those with LTV in the results of improving respiratory acidosis.But the incidence of(ventilated-)induced lung injury(VILI) was lower in LTV patients.Conclusion LTV ventilation is preferable for children with acute respiratory failure and beneficial for alleviation of VILI.

Analysis of Prognositic Factors of Severe Traumatic Brain Injury in Pediatric Intensive Care Unit / 实用儿科临床杂志

5 days.Blood gas analysis and blood pressure were determined at admitted day.Meanwhile,peripheral white blood cells at d1,3,5,and blood glucose were measured every day,respectively.GCS at d1,3,5 and hyperglycemia scorce(HS) were evaluated.Results Of the 82 studied patients,36 cases died.Univariate analysis showed that hypotension,lower GCS,higher peripheral white blood cells and HS were the independent death risk factors(Pa0.05).In multivariate logistic regression,the factors significantly associated with an increase in mortality were hypotension,lower GCS and higher HS.Conclusion Lower GCS,higher HS and hypotension are associated with poor outcome of children with severe trauma brain injury.