What is new in ventilation strategies for the neonate?

[Apllication of nasal synchronous intermittent mandatory ventilation in premature infants with severe respiratory distress syndrome after extubation]

OBJECTIVE

To study the clinical efficacy of nasal synchronous intermittent mandatory ventilation (nSIMV) in premature infants with severe respiratory distress syndrome (RDS) after extubation.

METHODS

A retrospective analysis on the clinical date of 126 premature infants with severe RDS who were hospitalized in the NICU between January 2013 and May 2015 was performed. Sixty-one premature infants who were hospitalized in the NICU between January 2013 and March 2014 received nasal continuous positive airway pressure (nCPAP) (nCPAP group) and 65 premature infants who were hospitalized in the NICU between April 2014 and May 2015 received nSIMV (nSIMV group). The blood gas analysis indexes, the rate of extubation failure, the causes of extubation failure and the incidence of complications were compared between the two groups.

RESULTS

After 4 hours of treatment, the pH value, PaO2, SaO2 and oxygenation index in the nSIMV group were significantly higher than in the nCPAP group (P<0.05), meanwhile, the PaCO2 in the nSIMV group were significantly lower than in the nCPAP group (P<0.05). The rates of extubation failure in the nSIMV and nCPAP groups were 9% (6/65) and 30% (18/61) respectively (P<0.05). The extubation failure in the nSIMV and nCPAP groups was caused by hyoxemia (2% vs 5%; P>0.05), hypercapnia (6% vs 11%; P>0.05) and apnea (2% vs 13%; P<0.05). There were no differences in respirator support time, full enteral feeding time, the time to regain birth weight and the length of hospitalization between two groups (P>0.05). After treatment, the incidence of abdominal distension in the nSIMV group was significantly lower than in the nCPAP group (9% vs 30%; P<0.05) and there were no differences in the incidences of feeding intolerance, necrotizing enterocolitis, intraventricular hemorrhage, retinopathy of prematurity and bronchopulmonory dysplasia between the two groups.

CONCLUSIONS

nSIMV for premature infants with severe RDS after extubation not only significantly improves lung function and reduces the rate of extubation failure, also results in a lower incidence of gastrointestinal side effects and does not increase the incidence of complications.

Current perspectives for management of acute respiratory insufficiency in premature infants with acute respiratory syndrome

Current perspectives for management of acute respiratory insufficiency in premature infants with acute respiratory syndrome and the pathology of acute respiratory insufficiency in the preterm infant, including the current therapy modalities on disposition are presented. Since the therapeutical challenge and primary clinical goal are to normalize ventilation ratio and lung perfusion, when respiratory insufficiency occurs, it is very important to introduce the respiratory support as soon possible, in order to reduce development of pulmonary cyanosis and edema, and intrapulmonary or intracardial shunts. A characteristic respiratory instability that reflects through fluctuations in gas exchange and ventilation is often present in premature infants. Adapting the respiratory support on a continuous basis to the infant's needs is challenging and not always effective. Although a large number of ventilation strategies for the neonate are available, there is a need for additional consensus on management of acute respiratory distress syndrome in pediatric population lately redefined by Berlin definition criteria, in order to efficiently apply various modes of respiratory support in daily pediatrician clinical use.

Lung function and respiratory health at school age in ventilated very low birth weight infants

OBJECTIVE

To investigate respiratory health and lung function in school-aged children without broncho-pulmonary dysplasia (BPD), who were very low birth weight (VLBWi) and randomized at birth to high frequency oscillatory ventilation (HFOV) or volume guarantee (VG) ventilation for severe respiratory distress syndrome (RDS).

METHODS

In this observational study, 7-y-old ex-preterm infants with severe RDS, randomly assigned at birth to receive assisted/control ventilation + VG (Vt = 5 mL/kg, PEEP = 5 cmH2O)(VG group; mean GA 27 ± 2 wk; mean BW 1086 ± 158 g) or HFOV (HFOV group; mean GA: 27 ± 2; mean BW: 1090 ± 139 g) (both groups were ventilated with Drager Babylog 8000 plus) were recalled. Neonatal clinical data and outcome were known. Actual outcomes were investigated with an interview; lung function was measured by whole-body plethysmography.

RESULTS

Twenty five children were studied (VG group, n = 13 vs. HFOV group, n = 12). There were no differences in anthropometric data, drugs (steroids/bronchodilators and antibiotics) or hospital readmission for respiratory disorders. Compliance to the test was adequate. The authors found a similar obstructive deficit (elevated values: airway resistance (RAW), residual volume (RV), total lung capacity (TLC) with near-normal spirometry) in both groups suggesting a persistent airflow limitation even in absence of BPD.

CONCLUSIONS

VLBW infants even in absence of BPD, need long term respiratory follow-up, because they frequently show an impairment of lung function, independent from initial respiratory support, even if at birth the choice is a lung protective approach (e.g., HFOV or VG ventilation).

Trends in survival among extremely-low-birth-weight infants (less than 1000 g) without significant bronchopulmonary dysplasia

Objective

The aim of this study was to analyze the evolution from 1997 to 2009 of survival without significant (moderate and severe) bronchopulmonary dysplasia (SWsBPD) in extremely-low-birth-weight (ELBW) infants and to determine the influence of changes in resuscitation, nutrition and mechanical ventilation on the survival rate.

Study design

In this study, 415 premature infants with birth weights below 1000 g (ELBW) were divided into three chronological subgroups: 1997 to 2000 (n = 65), 2001 to 2005 (n = 178) and 2006 to 2009 (n = 172).

Between 1997 and 2000, respiratory resuscitation in the delivery room was performed via a bag and mask (Ambu®, Ballerup, Sweden) with 40-50% oxygen. If this procedure was not effective, oral endotracheal intubation was always performed. Pulse oximetry was never used. Starting on January 1, 2001, a change in the delivery room respiratory policy was established for ELBW infants. Oxygenation and heart rate were monitored using a pulse oximeter (Nellcor®) attached to the newborn’s right hand. If resuscitation was required, ventilation was performed using a face mask, and intermittent positive pressure was controlled via a ventilator (Babylog2, Drägger). In 2001, a policy of aggressive nutrition was also initiated with the early provision of parenteral amino acids. We used standardized parenteral nutrition to feed ELBW infants during the first 12–24 hours of life. Lipids were given on the first day. The glucose concentration administered was increased by 1 mg/kg/minute each day until levels reached 8 mg/kg/minute. Enteral nutrition was started with trophic feeding of milk. In 2006, volume guarantee treatment was instituted and administered together with synchronized intermittent mandatory ventilation (SIMV + VG). The complications of prematurity were treated similarly throughout the study period. Patent ductus arteriosus was only treated when hemodynamically significant. Surgical closure of the patent ductus arteriosus was performed when two courses of indomethacin or ibuprofen were not sufficient to close it.

Mild BPD were defined by a supplemental oxygen requirement at 28 days of life and moderate BPD if breathing room air or a need for <30% oxygen at 36 weeks postmenstrual age or discharge from the NICU, whichever came first. Severe BPD was defined by a supplemental oxygen requirement at 28 days of life and a need for greater than or equal to 30% oxygen use and/or positive pressure support (IPPV or nCPAP) at 36 weeks postmenstrual age or discharge, whichever came first. Moderate and severe BPD have been considered together as “significant BPD”. The goal of pulse oximetry was to maintain a hemoglobin saturation of between 88% and 93%. Patients were considered to not need oxygen supplementation when it could be permanently withdrawn. The distribution of the variables was not normal based on a Kolmogorov-Smirnov test (p < 0.05 in all cases). Therefore, quantitative variables were expressed as the median and interquartile range (IQR; 25^th-75^th percentile). Statistical analysis of the data was performed using nonparametric techniques (Kruskal-Wallis test and Mann–Whitney U test). A chi-square analysis was used to analyze qualitative variables. Potential confounding variables were those possibly related to BPD in survivors (p between 0.05 and 0.3 in univariate analysis). Logistic regression analysis was performed with variables related to BPD in survivors (p < 0.05) and potential confounding variables. The forward stepwise method adjusted for confounding factors was used to select the variables, and the enter method using selected variables was used to obtain the odds ratios.

Results and conclusion

There was an increase in the rate of SWsBPD (1997 to 2000: 58.5%; 2001 to 2005: 74.2%; and 2006 to 2009: 75.0%; p = 0.032). In survivors, the occurrence of significant BPD decreased after 2001 (9.5% vs. 2.3%; p = 0.013). The factors associated with improved SWsBPD were delivery by caesarean section, a reduced endotracheal intubation rate and a reduced duration of mechanical ventilation.While the mortality of ELBW infants has not changed since 2001, the frequency of SWsBPD has significantly increased (75.0%) in association with increased caesarean sections and reductions in the endotracheal intubation rate, as well as the duration of mechanical ventilation.

Neonatal red blood cell transfusions: searching for better guidelines

BACKGROUND

Packed red blood cell (RBC) transfusions are often administered to patients in the neonatal intensive care unit. The purpose of this study was to determine whether current blood transfusion guidelines are as useful as care givers' perception in identifying patients in need of a packed RBC transfusion.

DESIGN AND METHODS

Health care providers were asked to complete a pre- and post-transfusion survey on neonates receiving a packed RBC transfusion. These patients were divided into three groups based on reasons for transfusion: (i) guidelines; (ii) care-givers' perceptions of need for packed RBC transfusion; or (iii) both. These three groups were further subdivided into two cohorts according to whether they had a clinical improvement or not. Demographic data and clinical variables were compared between the groups.

RESULTS

Seventy-eight care-givers were surveyed. Eighteen patients (23%) were transfused based on guidelines, 36 (46%) based on care givers' perception and 24 (31%) based on both. Neonates transfused based on guidelines alone were more likely to have received the transfusion in the first week of life, had a higher pre-transfusion haematocrit, were less symptomatic and had a higher trend to require mechanical ventilation. Neonates transfused based on caregivers' perception were more likely to be on non-invasive ventilatory support and were more symptomatic. Neonates who improved after a transfusion had a lower pre-transfusion haematocrit (p=0.02), were more symptomatic (p=0.01) and were more likely to be on non-invasive ventilatory support (p=0.002) when compared to the group without a clinical improvement. The group without improvement had an increase in oxygen requirement (+2.8±6.4) after the transfusion (p=0.0004). Tachycardia was the most sensitive predictor of a benefit from packed RBC transfusion [OR 6.48: p=0.005].

DISCUSSION

Guidelines on when to transfuse stable growing neonates with packed RBC should be re-evaluated to include more care giver judgement and perhaps be more restrictive for critically ill neonates.