OBJECTIVES: To investigate the efficacy of volume-guaranteed high-frequency oscillatory ventilation (HFOV-VG) in preterm infants with respiratory distress syndrome (RDS) and its impact on blood flow in the middle cerebral artery (MCA). METHODS: A prospective study was conducted on 120 preterm infants with RDS who were admitted to the Department of Neonatology at Qinhuangdao Maternal and Child Health Hospital from March 2020 to December 2023. According to the mode of ventilation, the infants were divided into two groups: a conventional mechanical ventilation (CMV) group (60 infants) and an HFOV-VG group (60 infants). The two groups were compared in terms of baseline data, MCA hemodynamic parameters, complications, and outcomes. RESULTS: Compared with the CMV group, the HFOV-VG group had significantly shorter durations of mechanical ventilation and hospital stay and a significantly higher overall response rate (P<0.05). The HFOV-VG group demonstrated significantly better peak systolic velocity, end-diastolic velocity, and mean flow velocity (P<0.05). The HFOV-VG group also exhibited significantly lower 28-day mortality rates and lower incidence rates of bronchopulmonary dysplasia and intraventricular hemorrhage than the CMV group (P<0.05). CONCLUSIONS HFOV-VG can effectively improve cerebral blood perfusion, reduce cerebrovascular resistance, shorten the durations of mechanical ventilation and hospital stay, and enhance overall treatment efficacy. It has significant advantages in reducing the risk of 28-day mortality, bronchopulmonary dysplasia, and intraventricular hemorrhage in preterm infants with RDS.
Humans ; High-Frequency Ventilation/adverse effects* ; Infant, Newborn ; Respiratory Distress Syndrome, Newborn/physiopathology* ; Female ; Middle Cerebral Artery/physiology* ; Male ; Prospective Studies ; Cerebrovascular Circulation ; Infant, Premature

OBJECTIVETo compare the therapeutic effects of high-frequency oscillatory ventilation+pulmonary surfactant (HFOV+PS), conventional mechanical ventilation+pulmonary surfactant (CMV+PS), and conventional mechanical ventilation (CMV) alone for acute lung injury/acute respiratory distress syndrome (ALI/ARDS) in neonates.

METHODSA total of 136 neonates with ALI/ARDS were enrolled, among whom 73 had ALI and 63 had ARDS. They were divided into HFOV+PS group (n=45), CMV+PS group (n=53), and CMV group (n=38). The neonates in the first two groups were given PS at a dose of 70-100 mg/kg. The partial pressure of oxygen (PaO), partial pressure of carbon dioxide (PaCO), PaO/fraction of inspired oxygen (FiO), oxygenation index (OI), and respiratory index (RI) were measured at 0, 12, 24, 48, and 72 hours of mechanical ventilation.

RESULTSAt 12, 24, and 48 hours of mechanical ventilation, the HFOV+PS group had higher PaOand lower PaCOthan the CMV+PS and CMV groups (P<0.05). At 12, 24, 48, and 72 hours of mechanical ventilation, the HFOV+PS group had higher PaO/FiOand lower OI and RI than the CMV+PS and CMV groups (P<0.05). The HFOV+PS group had shorter durations of mechanical ventilation and oxygen use than the CMV+PS and CMV groups (P<0.05). There were no significant differences in the incidence rates of air leakage and intracranial hemorrhage and cure rate between the three groups.

CONCLUSIONSIn neonates with ALI/ARDS, HFOV combined with PS can improve pulmonary function more effectively and shorten the durations of mechanical ventilation and oxygen use compared with CMV+PS and CMV alone. It does not increase the incidence of complications.

Acute Lung Injury ; physiopathology ; therapy ; Combined Modality Therapy ; Female ; High-Frequency Ventilation ; Humans ; Infant, Newborn ; Male ; Pulmonary Surfactants ; therapeutic use ; Respiratory Distress Syndrome, Newborn ; physiopathology ; therapy ; Respiratory Mechanics

OBJECTIVETo investigate the pulmonary function after treatment in neonates with respiratory distress syndrome (RDS) at varying disease severity levels and different gestational ages.

METHODSA total of 107 neonates with RDS were divided into <34 weeks group (65 neonates), late preterm group (21 neonates), full-term group (21 neonates). Another 121 non-RDS children were enrolled as the control group. According to the severity of RDS, the RDS neonates were divided into mild RDS group (grades 1 and 2; 76 neonates), and severe RDS (grades 3 and 4; 21 neonates). The tidal breathing pulmonary function was measured at a corrected gestational age of 44weeks.

RESULTSThe pulmonary function parameters showed no significant differences across the groups of RDS neonates of different gestational ages; the tidal volume per kilogram of body weight (VT/kg) showed no significant difference between the RDS and non-RDS groups, while the RDS group had significantly higher ratio of time to peak tidal expiratory flow to total expiratory time (tPTEF/tE) and ratio of volume to peak tidal expiratory flow to total expiratory volume (vPTEF/vE) than the non-RDS group of the same gestational age (P<0.05). At a corrected gestational age of 44 weeks, the two groups of neonates with varying severity levels of RDS had significantly lower tPTEF/tE and vPTEF/vE than the control group (P<0.05), and tPTEF/tE and vPTEF/vE tended to decrease with the increasing severity level of RDS.

CONCLUSIONSNeonates with RDS have significantly decreased pulmonary function than those without RDS. At a corrected gestational age of 44 weeks, the tidal breathing pulmonary function in neonates with RDS is not associated with gestational age, but is associated with the severity of RDS.

Female ; Gestational Age ; Humans ; Infant, Newborn ; Lung ; physiopathology ; Male ; Respiratory Distress Syndrome, Newborn ; physiopathology

OBJECTIVETo study clinical characteristics and evaluate cardiac hemodynamic changes in premature infants with patent ductus ateriosus (PDA).

METHODOne hundred and five infants born at ≤ 34 weeks' gestational age (GA) and ≤2 000 g birth weight (BW) were prospectively enrolled, including 63 males and 42 females, and the mean GA was (31. 1 ± 1.9) weeks and BW (1 401 ± 314) g. Echocardiography was done to detect hemodynamically significant PDA (hsPDA) and to evaluate left ventricular function at 2, 3, 5 and 7 d respectively after birth. On the basis of clinical symptoms and echocardiographic outcome, all the cases were divided into 3 groups: hsPDA group (n = 34), non-hsPDA (nhsPDA) group (n = 44) and non-PDA (nPDA) group (n = 27) to survey and compare general conditions, DA diameter, shunt direction, left ventricular function and complications.

RESULTThe hsPDA group had smaller GA ((30. 5 ± 2. 1) vs. (31. 6 ± 1. 6) weeks, P = 0. 01) and greater proportion of pulmonary surfactant use and mechanical ventilation (2, 3, 5 d of birth) than the nhsPDA and the nPDA group (χ2 = 11. 62, 14. 95, 12. 73, 1:1. 59, P = 0. 00; 0. 00, 0. 01, 0. 01). Univariate and multivariate Logistic regression analysis indicated that the average length of stay (ALOS) was correlated with hsPDA (F =3. 52 and P =0. 03, OR 1. 03 and P =0. 02). The ALOS was longer in the hsPDA group than in the nhsPDA and the nPDA group ((39 ±23)vs. (30 ± 16)and(29 ±13) d, P =0.02, 0.03). There was no significant.difference in rates of mortality/giving-up of treatment among the three groups (5. 9% (2/34)vs. 0 (0/44) and 3. 7% (1/27), χ2 = 5. 26, P = 0. 06). Diastolic blood pressure and mean blood pressure were significantly lower in the hsPDA group than in the other two groups (P all <0. 05) at 2, 3 and 5 days after birth and the pulse pressure was found significantly higher in the hsPDA group than in the nPDA group at 2 d after birth. Univariate and multivariate Logistic regression analysis demonstrated that hsPDA was correlated significantly with neonatal respiratory distress syndrome (NRDS) and bronchopulmonary dysplasia (BPD) (χ2 =7. 34 and 7. 39, P = 0. 02 and 0. 02; OR = 3. 46 and 4. 01, P = 0. 04 and 0. 02). Premature infants with hsPDA had normal left ventricular fractional shortening (FS) and left ventricular ejection fraction (LVEF), although the cardiac output (CO) of left ventricle increased significantly(F = 6. 93, P <0. 01) within seven days of birth. There was no significant difference in cardiac hemodynamic parameters among closed group of hsPDA group, nhsPDA group and nPDA group simutaneously reexamined at 7th day after birth. The CO was extremely significantly different among premature infants who had different GAs and BWs. The lower the GAs and the BWs, the lower the value of CO(F =5. 16 and 14. 87, P all <0. 01). The DA diameter was reduced much more dramatically after ibuprofen treatment than before in hsPDA group(t = 5. 58, P <0. 01).

CONCLUSIONThe GA, PS use and mechanical ventilation were probably associated with hsPDA. The mean blood pressure and diastolic blood pressure were decreased and pulse pressure was increased in preterm infants with hsPDA that correlated significantly with ALOS, NRDS and BPD. In addition, increased CO values were found in hsPDA group. Oral ibuprofen administered to preterm infants for hsPDA at > 24 h of life promoted ductal closure.

Birth Weight ; Bronchopulmonary Dysplasia ; Cardiac Output ; Cyclooxygenase Inhibitors ; therapeutic use ; Ductus Arteriosus, Patent ; physiopathology ; Echocardiography ; Female ; Gestational Age ; Hemodynamics ; Humans ; Ibuprofen ; therapeutic use ; Infant, Newborn ; Infant, Premature ; Infant, Premature, Diseases ; Male ; Pulmonary Surfactants ; Respiration, Artificial ; Respiratory Distress Syndrome, Newborn ; Ventricular Function, Left

OBJECTIVETo understand the effect of lung recruitment maneuver (LRM) with positive end-expiratory pressure (PEEP) on oxygenation and outcomes in preterm infants with respiratory distress syndrome (RDS) ventilated by proportional assist ventilation (PAV).

METHODFrom January 2012 to June 2013, thirty neonates with a diagnosis of RDS who required mechanical ventilation were divided randomly into LRM group (n=15, received an LRM and surport by PAV) and control group (n=15, only surport by PAV). There were no statistically significant differences in female (7 vs. 6); gestational age [(29.3±1.2) vs. (29.5±1.1) weeks]; body weight[(1,319±97) vs. (1,295±85) g]; Silverman Anderson(SA) score for babies at start of ventilation (7.3±1.2 vs. 6.9±1.4); initial FiO2 (0.54±0.12 vs. 0.50±0.10) between the two groups (all P>0.05). LRM entailed increments of 0.2 cmH2O (1 cmH2O=0.098 kPa) PEEP every 5 minutes, until fraction of inspired oxygen (FiO2)=0.25. Then PEEP was reduced and the lung volume was set on the deflation limb of the pressure/volume curve.When saturation of peripheral oxygen fell and FiO2 rose, we reincremented PEEP until SpO2 became stable. The related clinical indicators of the two group were observed.

RESULTThe doses of surfactant administered (1.1±0.3 vs. 1.5±0.5, P=0.027), Lowest FiO2 (0.29±0.05 vs. 0.39±0.06, P=0.000), time to lowest FiO2[ (103±18) vs. (368±138) min, P=0.000] and O2 dependency [(7.6±1.0) vs.( 8.8±1.3) days, P=0.021] in LRM group were lower than that in control group (all P<0.05). The maximum PEEP during the first 12 hours of life [(8.4±0.8) vs. (6.8±0.8) cmH2O, P=0.000] in LRM group were higher than that in control group (P<0.05). FiO2 levels progressively decreased (F=35.681, P=0.000) and a/AO2 Gradually increased (F=37.654, P=0.000). No adverse events and no significant differences in the outcomes were observed.

CONCLUSIONLRM can reduce the doses of pulmonary surfactant administered, time of the respiratory support and the oxygen therapy in preterm children with RDS.

Female ; Humans ; Infant, Newborn ; Infant, Premature ; Interactive Ventilatory Support ; methods ; Lung ; physiopathology ; Male ; Oxygen ; administration & dosage ; Oxygen Inhalation Therapy ; Positive-Pressure Respiration ; methods ; Pulmonary Surfactants ; administration & dosage ; Respiration ; Respiration, Artificial ; Respiratory Distress Syndrome, Newborn ; physiopathology ; therapy ; Tidal Volume ; Treatment Outcome

Newfactan(R) is a domestically developed, bovine lung-derived, semi-synthetic surfactant. The aim of this study was to compare the clinical efficacy of Newfactan(R) with that of Surfacten(R) in the treatment of respiratory distress syndrome (RDS). Newfactan(R) or Surfacten(R) was randomly allocated to 492 newborn infants who were diagnosed as RDS and required surfactant instillation in four participating hospitals. The comparisons were made individually in two subsets of infants by birth weight (<1,500 g group [n=253] and >or=1,500 g group [n=239]). Short-term responses to surfactant and acute complications, such as the total doses of surfactant instilled, response type, extubation rate, ventilator settings, changes in respiratory parameters, air leak, patent ductus arteriosus, pulmonary hemorrhage, and intraventricular hemorrhage, and mortality during the 96 hr after surfactant instillation were measured. Long-term outcome and complications, such as total duration of intubation, bronchopulmonary dysplasia and periventricular leukomalacia, and ultimate mortality were measured. There were no significant differences in demographic and perinatal variables, shortterm responses to surfactant and acute complications, and long-term outcome and complications between Newfactan(R) and Surfacten(R) in both birth weight groups. We concluded that Newfactan(R) was comparable to Surfacten(R) in the clinical efficacy in the treatment of RDS in both birth weight groups.
Comparative Study ; Female ; Humans ; Infant, Newborn ; Lung/drug effects/pathology/physiopathology ; Male ; Pulmonary Surfactants/*therapeutic use ; Research Support, Non-U.S. Gov't ; Respiratory Distress Syndrome, Newborn/*drug therapy/mortality ; Survival Rate ; Time Factors ; Treatment Outcome

OBJECTIVEThe authors compared the protective ventilation strategies with the assistance of pulmonary mechanic measurements (PM) to the conventional ventilation practice in order to investigate the incidence of VALI, explore the best ventilator settings in RDS and the clinical effects of hypercapnia in neonates.

METHODSOne hundred and ten newborn infants, diagnosed as respiratory distress syndrome of neonatal and needed ventilator support, were recruited from the intensive care unit from 1994 to 2001. Infants with RDS were divided into non-pulmonary mechanics measurement (NPM) group and pulmonary mechanics measurement (PM) group. The ventilator settings, artery blood gas analysis, ventilator-associated lung injury and other clinical data were analyzed and compared.

RESULTSIn the PM group, expiratory tidal volume of (7.70 +/- 1.05) ml/kg, C(20)/C of (1.98 +/- 0.92) and time constant of (0.09 +/- 0.03) sec were measured. Ventilator setting in PM group [PIP of (26.7 +/- 1.7) cmH(2)O, MAP of (11.9 +/- 2.0) cmH(2)O, Ti of (0.45 +/- 0.10) sec] were significantly less than those in NPM group [PIP of (30.5 +/- 3.4) cmH(2)O, MAP of (14.9 +/- 3.4) cmH(2)O, Ti of (0.75 +/- 0.10) sec P < 0.001, respectively]. No differences were noted in demographic data between the two groups regarding to the pH (7.30 +/- 0.04 vs 7.31 +/- 0.10), PaO(2) [(59 +/- 16) vs (57 +/- 17) mmHg], heart rate [(145 +/- 6) vs (144 +/- 8) bpm] and blood pressure [(39.0 +/- 3.6) vs (40.0 +/- 4.6) mmHg], except for PaCO(2) in PM group which was significantly higher than that in NPM group [(48 +/- 6) vs (40 +/- 10) mmHg, P < 0.001]. OI in PM group was significantly less than that in NPM group (14 +/- 8 vs 19 +/- 13, P < 0.05). Incidence of ventilator-associated lung injury in PM group was significantly lower than that in NPM group (13% vs 32%, P < 0.05). No differences were noted in demographic data between the two groups regarding to the length of ventilator support [(4.2 +/- 1.7) vs (3.9 +/- 1.8) day], length of supplemental oxygen requirements [(13 +/- 7) vs (11 +/- 7) day], length of hospitalization [(22 +/- 11) vs (19 +/- 14) day], mortality (8% vs 14%), incidence of PDA (33 vs 36%) and IVH (40% vs 42%).

CONCLUSIONSThe assistance use of pulmonary mechanics measurement can guide the ventilator adjustment and decrease the ventilator-associated lung injury in neonatal RDS. The low PIP, low tidal volume, shorter inspiratory time and adequate PEEP strategies in the treatment of RDS showed no significant effects on the oxygenation in neonates. The mild permissive hypercarbia in newborn did not increase the incidence of IVH.

Blood Gas Analysis ; Female ; Humans ; Infant, Newborn ; Intensive Care Units, Neonatal ; Male ; Respiration, Artificial ; methods ; Respiratory Distress Syndrome, Newborn ; physiopathology ; therapy ; Respiratory System ; physiopathology

OBJECTIVETo evaluate dose response of inhaled nitric oxide (iNO) for surfactant-treated rabbits with meconium aspiration-induced acute lung injury (ALI) and hypoxemic respiratory failure (HRF), and variation of measured iNO by continuous NO delivery in pressure support ventilation (PSV).

METHODSAdult rabbits (2.0 - 3.5 kg, n = 33) were randomized to receive intratracheal meconium instillation for 30 min and subjected to following treatment (n = 6 - 8). There were 4 groups: Control (C); NO, iNO at 1, 10, 20 and 40 x 10(-6) each for 60 min at 30 min interval of disconnection; Surf, intratracheal instillation of porcine lung surfactant phospholipids (100 mg/kg); SNO, both iNO and surfactant as in the NO and Surf groups; and a normal group (N), which did not undergo meconium aspiration but received sham deliveries of normal saline. All the animals were treated with PSV for 6 h. iNO levels at different input and sampling sites in the NO and SNO groups were detected by on-line chemiluminescent technique. The blood gas and lung mechanics were measured during the experiments every 2 h.

RESULTS(1) Meconium aspiration induced ALI and severe HRF (PaO(2)/FiO(2) < 200 mmHg) and depressed dynamic compliance of respiratory system (Cdyn) and airway resistance (Raw). In both Surf and NO groups modestly improved oxygenation was observed. In the SNO, values for PaO(2)/FiO(2) were improved from (185 +/- 39) mmHg at baseline to (301 +/- 123) mmHg at 6 h, while moderate or transient improvement was observed in both Surf and NO groups. Cdyn and Raw were only improved for short time in the Surf, NO and SNO groups. iNO had a mild response at 1 x 10(-6) to good response at 10 and 20 x 10(-6), but no further improvement occurred at 40 x 10(-6). The response of iNO in NO group was relatively transient compared to the SNO group. (2) When iNO was connected to the ventilator circuit, the connected site should be placed before humidifier to minimize fluctuation of iNO concentration, and sampling site for iNO monitoring should be placed adequately to eliminate artifact.

CONCLUSIONSiNO synergistically improved surfactant effects on oxygenation and lung mechanics. Continuous supply of iNO with non-continuous flow ventilator provided stable NO within accepted target range with least variation.

Administration, Inhalation ; Animals ; Drug Therapy, Combination ; Female ; Humans ; Infant, Newborn ; Lung ; drug effects ; pathology ; physiopathology ; Male ; Meconium ; Meconium Aspiration Syndrome ; complications ; Nitric Oxide ; administration & dosage ; therapeutic use ; Phospholipids ; therapeutic use ; Pulmonary Surfactants ; therapeutic use ; Pulmonary Ventilation ; Rabbits ; Random Allocation ; Respiratory Distress Syndrome, Adult ; etiology ; therapy ; Treatment Outcome

This study was performed to elucidate the mechanism of improved oxygenation after surfactant replacement therapy in respiratory distress syndrome (RDS) of the newborn infants. In 26 newborns with RDS, end tidal-CO2 tension (PetCO2), arterial blood gas analysis and pulmonary function tests were measured at baseline, 30 min, 2 hr and 6 hr after surfactant administration. The changes in dead space/tidal volume ratio (VD/VT ratio=(PaCO2-PetCO2)/PaCO2), oxygenation index and arterial-alveolar partial pressure difference for oxygen ((A-a)DO2) were elucidated and correlated with pulmonary mechanics. Oxygenation index and (A-a)DO2 improved, and VD/VT ratio decreased progressively after surfactant administration, becoming significantly different from the baseline at 30 min and thereafter with administration of surfactant. Pulmonary mechanics did not change significantly during the observation period. VD/VT ratio showed close correlation with OI and (A-a)DO2, but not with pulmonary mechanics. These results suggest that decreased physiologic dead space resulting from the recruitment of atelectatic alveoli rather than improvement in pulmonary mechanics is primarily responsible for the improved oxygenation after surfactant therapy in the RDS of newborn.
Airway Resistance ; Human ; Infant, Newborn ; Lung/physiopathology* ; Lung Compliance ; Pulmonary Gas Exchange ; Pulmonary Surfactants/therapeutic use* ; Respiratory Dead Space* ; Respiratory Distress Syndrome/physiopathology ; Respiratory Distress Syndrome/drug therapy* ; Tidal Volume*

Pathologic findings of scrub typhus have been characterized by vasculitis of the microvasculature of the involved organ resulting from a direct invasion by Orientia tsutsugamushi. We experienced a case of acute respiratory distress syndrome (ARDS) associated with scrub typhus. The case was proven by eschar and high titer of serum IgM antibody (positive at 1:1280). Open lung biopsy showed diffuse alveolar damage (DAD) in the organizing stage without evidence of vasculitis. Immunofluorescent antibody staining and polymerase chain reaction for O. tsutsugamushi failed to demonstrate the organism in the lung tissue. The patient expired due to progressive respiratory failure despite doxycycline therapy. Immunologic mechanism, without direct invasion of the organism, may participate in the pathogenesis of ARDS associated with scrub typhus.
Acute Disease ; Aged ; Case Report ; Fatal Outcome ; Female ; Human ; Infant, Newborn ; Pulmonary Alveoli/pathology ; Pulmonary Alveoli/injuries ; Respiratory Distress Syndrome/physiopathology ; Respiratory Distress Syndrome/pathology ; Respiratory Distress Syndrome/immunology ; Respiratory Distress Syndrome/complications* ; Scrub Typhus/physiopathology ; Scrub Typhus/pathology ; Scrub Typhus/immunology ; Scrub Typhus/complications* ; Vasculitis