Respiratory Care for the Ventilated Neonate

Early and consistent safe sleep practices in the neonatal intensive care unit: a sustained regional quality improvement initiative

OBJECTIVE

To increase compliance with standardized safe sleep recommendations for patients in a cohort of regional level III/IV neonatal intensive care units (NICUs) in accordance with recently revised guidelines issued by the American Academy of Pediatrics (AAP).

STUDY DESIGN

A regional quality improvement (QI) initiative led by a multidisciplinary task force standardized safe sleep criteria across participating NICU sites. Universal and unit-specific interventions were implemented via Plan-Do-Study-Act (PDSA) cycles with evaluation of compliance through routine crib audits, run chart completion, and Pareto chart analysis.

RESULTS

Following QI implementation, compliance with safe sleep guidelines for eligible NICU infants improved from 34% to 90% from October 2019 through September 2022.

CONCLUSION

Compliance with early, consistent modeling of safe sleep practices nearly tripled in this cohort of regional NICUs. A standardized, timely approach to safe sleep transition demonstrated dramatic and sustained improvement in the practice and modeling of safe sleep behaviors in the NICU.

Predictive Value of Neutrophil-to-Monocyte Ratio, Lymphocyte-to-Monocyte Ratio, C-Reactive Protein, Procalcitonin, and Tumor Necrosis Factor Alpha for Neurological Complications in Mechanically Ventilated Neonates Born after 35 Weeks of Gestation

This prospective study investigated the association between elevated neutrophil-to-monocyte ratio (NMR), lymphocyte-to-monocyte ratio (LMR), C-reactive protein (CRP), procalcitonin, and tumor necrosis factor-alpha (TNF-alpha) and the risk of developing neurological complications in mechanically ventilated neonates. The aim was to evaluate these biomarkers' predictive value for neurological complications. Within a one-year period from January to December 2022, this research encompassed neonates born at ≥35 weeks of gestational age who required mechanical ventilation in the neonatal intensive care unit (NICU) from the first day of life. Biomarkers were measured within the first 24 h and at 72 h. Sensitivity, specificity, and area under the curve (AUC) values were calculated for each biomarker to establish the best cutoff values for predicting neurological complications. The final analysis included a total of 85 newborns, of which 26 developed neurological complications and 59 without such complications. Among the studied biomarkers, TNF-alpha at >12.8 pg/mL in the first 24 h demonstrated the highest predictive value for neurological complications, with a sensitivity of 82%, specificity of 69%, and the highest AUC (0.574, p = 0.005). At 72 h, TNF-alpha levels greater than 14.3 pg/mL showed further increased predictive accuracy (sensitivity of 87%, specificity of 72%, AUC of 0.593, p < 0.001). The NMR also emerged as a significant predictor, with a cutoff value of >5.3 yielding a sensitivity of 78% and specificity of 67% (AUC of 0.562, p = 0.029) at 24 h, and a cutoff of >6.1 showing a sensitivity of 76% and specificity of 68% (AUC of 0.567, p = 0.025) at 72 h. Conversely, CRP and procalcitonin showed limited predictive value at both time points. This study identifies TNF-alpha and NMR as robust early predictors of neurological complications in mechanically ventilated neonates, underscoring their potential utility in guiding early intervention strategies. These findings highlight the importance of incorporating specific biomarker monitoring in the clinical management of at-risk neonates to mitigate the incidence of neurological complications.

Lung ultrasound score for monitoring the withdrawal of extracorporeal membrane oxygenation on neonatal acute respiratory distress syndrome

BACKGROUND

Extracorporeal membrane oxygenation (ECMO) is considered an efficient and life-saving treatment for neonatal severe acute respiratory distress syndrome (ARDS). Bedside lung ultrasound (LUS) is an attractive and feasible method for evaluating neonatal ARDS.

OBJECTIVE

To evaluate the value of LUS score at veno-arterial (V-A) ECMO withdrawal in neonatal patients with severe acute ARDS.

METHODS

A retrospective preliminary study was conducted in our cardiac intensive care unit from June 2021 to June 2022. Eight severe ARDS neonates who received V-A ECMO were enroled in this study. LUS was measured daily during ECMO and when weaning off ECMO. The relationships between the LUS score and ECMO parameters (blood flow and the sweep gas of FiO2) were assessed.

RESULTS

(1) There was a significant improvement in LUS score by ECMO treatment. And, various diagnostic signs of lung ultrasound were detected during ECMO, including pulmonary edema (7 neonates) and lung consolidation (4 neonates), followed by pleural effusion (1 neonate) and bilateral white lung (1 neonate). (2) A total of 12 trials for weaning off ECMO were carried out, of which four failed, but all eight neonates finally succeeded in passing the weaning trial. LUS score of 21 or less was defined as a cut-off value for predicting ECMO weaning success. During ECMO treatment, LUS score was positively correlated with ECMO blood flow (r = 0.866, P < 0.05).

CONCLUSIONS

LUS can be used to evaluate the various lung diagnostic signs in ARDS neonatal patients during ECMO treatment, and the LUS score under ECMO treatment decreases over time. The reduction in LUS score is associated with lower ECMO blood flow. LUS score is regarded as a predictor of ECMO weaning success.

The prognostic value of red blood cell distribution width for pulmonary infection in elderly patients received abdominal surgery with tracheal intubation and general anesthesia

BACKGROUND

Red blood cell distribution width (RDW) has been shown to be an important predictor of the occurrence of various inflammatory and infectious diseases. However, the predictive value of RDW for pulmonary infection in elderly patients undergoing abdominal surgery under general anesthesia with endotracheal intubation remains unclear.

METHODS

A total of 200 eligible elderly patients who underwent abdominal surgery with endotracheal intubation and general anesthesia in our hospital from January 2019 to January 2022 were included in this study. During hospitalization, there were 64 cases with different degrees of pulmonary infection, and 136 cases without pulmonary infection. Participants' RDW levels were analyzed on admission. Serum levels of inflammatory factors in infected patients were analyzed during hospitalization. Multivariate logistic analysis was performed to evaluate clinical factors for pulmonary infection during hospitalization following-up abdominal surgery with endotracheal intubation and general anesthesia in elderly patients. Youden's J statistic was used to define the correlation.

RESULTS

RDW at admission was independently associated with the risk of pulmonary infection in elderly patients undergoing general anesthesia with endotracheal intubation for abdominal surgery ([OR 1.952, 95% confidence interval 1.604 to 2.279, p=0.006]). RDW at admission was statistically positively correlated with inflammatory factors, including procalcitonin (p<0.001), C-reactive protein (p<0.001), and tumor necrosis factor-α (p<0.001), in elderly patients with postoperative pneumonia who underwent abdominal surgery.

CONCLUSION

RDW at admission had predictive value for pulmonary infection in elderly patients undergoing abdominal surgery under general anesthesia with endotracheal intubation.

Idiopathic Pulmonary Hemorrhage in Infancy: A Case Report and Literature Review

Acute idiopathic pulmonary hemorrhage in infants (AIPHI) is a rare and quite low-described entity. Nowadays, pathophysiological mechanisms are poorly understood, although the lethality remains high. We present an autopsy case report of a 2-day-old male who developed respiratory distress and blood leakage from the endotracheal tube (ET) and suddenly died because of acute pulmonary hemorrhage. A postmortem examination and histological analysis were performed and are reported in this paper. Alveolar spaces were filled with red blood cells and hyaline membranes in all the examined samples. The absence of other findings led us to select a post-mortem diagnosis of AIPHI. To support our diagnosis, we conducted a systematic review of the updated scientific literature and found that only 61 cases have been reported. Most of them presented acute respiratory distress and bleeding from the upper airways with blood leakage from ET (9.83%), hemoptysis (52.45%), epistaxis (8.2%), and hematemesis (3.27%). The autopsy data revealed hemorrhages of the lower airways and hemosiderin-laden macrophages. The data from the scientific publications and our findings are essential to achieving a correct diagnosis. On these bases, we suggest autoptic criteria to achieve a post-mortem diagnosis of AIPHI.

Analgesia and sedation for intratracheal intubation in the neonatal period: an integrative literature review

OBJECTIVE

to assess evidence available in the literature about the use of sedation and analgesia for intratracheal intubation of newborns.

DATA SOURCES

by means of an integrative literature review, the authors looked for evidence related to the theme from the last ten years, indexed in the Pubmed, Medline, Lilacs, Scielo, and Scopus databases, by combining the descriptors: newborn, intratracheal intubation, and analgesia. Articles in Portuguese, English, and Spanish that met the research purpose were included.

DATA SUMMARY

After applying the eligibility criteria, ten articles on the topic were obtained, predominantly narrative reviews, retrospective studies, observational studies, and only one non-randomized clinical trial, which characterizes the literature related to the topic as having a low level of scientific evidence. There is still no consensus in the literature on which medications and indications are for use in non-elective intubations, despite the ethical recommendation.

DISCUSSION

pain and its deleterious effects should not be neglected. Neonatal Intensive Care Units should have their own protocols regarding sedation and analgesia for intubation considering the individual characteristics of each patient. There is an ethical recommendation regarding the use of sedation and analgesia for intubation since it is a known painful procedure.

Delivering Low Tidal Volume With Anesthesia and ICU Ventilators in a Neonatal Lung Model

BACKGROUND

Mechanical ventilation of the neonate requires ventilators than can deliver precise and accurate tidal volume (VT) and PEEP to avoid lung injury. Due to small neonatal VT and the disproportionate effect of endotracheal tube leak in these patients, accomplishing precise and accurate VT delivery is difficult. Whereas neonatal ICU ventilators are validated in this population, thorough studies testing the performance of anesthesia ventilators in delivering small VT in neonates are lacking.

METHODS

Three anesthesia ventilators, Dräger Apollo, GE Avance, and Getinge Flow-i; and 2 ICU ventilators, Medtronic PB980 and Nihon Kohden NKV-550, were tested under volume control mode at VT of 5, 20, 40, and 60 mL. Three combinations of lung compliance and airway resistance were tested using a Servo ASL 5000 lung simulator.

RESULTS

In a scenario without leak, the measured VT was greater than the set VT by > 10% in the Apollo (21.0% [18.8-26.0]); measured VT was less than the set VT by > 10% in the Flow-i (-19% [-20.8 to -18.7]). The Avance, PB980, and NKV-550 presented a volume error < 10% (-9.50% [-10.8 to -4.4], -5.8% [-11.8 to -3.5], and 5.4% [-4.5 to 18.9], respectively). Considering all combinations of set VT, leaks, and respiratory mechanics, none of the anesthesia ventilators were able to deliver a median measured VT within a 10% error. The bias between measured VT and set VT varied widely among ventilators (from 4.27 mL to -10.59 mL). Additionally, in the Apollo ventilator, PEEP was underdelivered with the largest leak value.

CONCLUSIONS

Our results suggest that in comparison with the 2 neonatal ICU ventilators tested, the anesthesia ventilators did not greatly differ in terms of VT delivery in the presence of a gas leak.

Ketamine Analgesia as an Alternative to General Anesthesia During Laser Treatment for Retinopathy of Prematurity

PURPOSE

To determine the safety and efficacy of ketamine analgesia as an alternative to general anesthesia during laser treatment for retinopathy of prematurity (ROP).

METHODS

Eighteen premature neonates with ROP underwent laser treatment. The procedure was performed in the operating room, and the neonates were admitted to the neonatal intensive care unit (NICU) after the procedure. An initial dose of 1 mg/kg of ketamine was administered. If the neonate exhibited movement or distress during the procedure, incremental doses of ketamine were administered. Perioperative ventilation status, severity of pain during the procedure, surgeon satisfaction, and perioperative events were recorded.

RESULTS

Eighteen premature neonates underwent ketamine analgesia during laser treatment for ROP. The procedure was performed in 16 patients with good tolerance and without events. The Premature Infant Pain Profile (PIPP) scores during the procedure were 5 or less in 12 neonates (44.4%), 5 to 10 in 4 neonates (22.2%), and greater than 10 in 2 (11.1%) neonates. Three neonates had perioperative events, which resolved completely with minimal intervention. None of the neonates needed intubation perioperatively, and hemodynamic instability, hypotension, and bradycardia were not recorded in any of the neonates during or after the procedure.

CONCLUSIONS

The ROP laser treatment under ketamine sedation could be performed in premature neonates with few perioperative complications and provide satisfactory operative conditions. [J Pediatr Ophthalmol Strabismus. 2022;59(6):416-421.].

Evaluation of three non-invasive ventilation modes after extubation in the treatment of preterm infants with severe respiratory distress syndrome

OBJECTIVE

To evaluate the efficacy and safety of three different modes of non-invasive post-extubation ventilation support in preterm infants with severe respiratory distress syndrome (RDS).

METHODS

Infants diagnosed with severe RDS after extubation were randomized to receive nasal continuous positive airway pressure ventilation (NCPAP), nasal intermittent positive pressure ventilation (NIPPV), and non-invasive high-frequency oscillatory ventilation (NHFO). The clinical outcomes and complications of infants in different groups were recorded.

RESULTS

In infants less than 32 weeks, NCPAP had a significant increase in extubation failure when compared with NIPPV and NHFO, and the gastrointestinal feeding time, the numbers of apnea, and hospitalization costs in the NCPAP group were significantly higher. The incidence of complications was also higher in the NCPAP group. There was no difference in clinical outcomes and complications in infants greater than 32 weeks.

CONCLUSION

For infants with severe RDS less than 32 weeks after extubation, NIPPV and NHFO are more cost-effective in comparison to NCPAP.

Energy-Efficient Respiratory Anomaly Detection in Premature Newborn Infants

Precise monitoring of respiratory rate in premature newborn infants is essential to initiating medical interventions as required. Wired technologies can be invasive and obtrusive to the patients. We propose a deep-learning-enabled wearable monitoring system for premature newborn infants, where respiratory cessation is predicted using signals that are collected wirelessly from a non-invasive wearable Bellypatch put on the infant’s body. We propose a five-stage design pipeline involving data collection and labeling, feature scaling, deep learning model selection with hyperparameter tuning, model training and validation, and model testing and deployment. The model used is a 1-D convolutional neural network (1DCNN) architecture with one convolution layer, one pooling layer, and three fully-connected layers, achieving 97.15% classification accuracy. To address the energy limitations of wearable processing, several quantization techniques are explored, and their performance and energy consumption are analyzed for the respiratory classification task. Results demonstrate a reduction of energy footprints and model storage overhead with a considerable degradation of the classification accuracy, meaning that quantization and other model compression techniques are not the best solution for respiratory classification problem on wearable devices. To improve accuracy while reducing the energy consumption, we propose a novel spiking neural network (SNN)-based respiratory classification solution, which can be implemented on event-driven neuromorphic hardware platforms. To this end, we propose an approach to convert the analog operations of our baseline trained 1DCNN to their spiking equivalent. We perform a design-space exploration using the parameters of the converted SNN to generate inference solutions having different accuracy and energy footprints. We select a solution that achieves an accuracy of 93.33% with 18× lower energy compared to the baseline 1DCNN model. Additionally, the proposed SNN solution achieves similar accuracy as the quantized model with a 4× lower energy.

Implementing a ventilation index for assessing indoor air PM2.5 concentrations in biomass-using households

Biomass combustion in indoor kitchens contributes a lot to the PM_2.5 exposure burden among millions of people worldwide. Emitted potential pollutants from the biomass combustion oven may enormously degrade indoor air quality during cooking time and impact crowded rooms with inadequate indoor ventilation. The concept of developing a "ventilation index" may be a valuable alternative to assess indoor air quality. A new empirical formula of the ventilation index has been proposed recently, in which multiple studies need to be validated by various studies. This study is a part of the validation process and has ended up with supportive evidence-based insight into residential indoor air quality. Ninety-three households were selected from 25 villages of Tamil Nadu, India, to monitor the parameters required to apply in the empirical formula. However, the association between indoor air velocity and PM_2.5 (considered a surrogate component of indoor air quality) was focused on emphatically. Other important variables, e.g., used amount of biomass cooking fuel, kitchen room index, room temperature, and relative humidity, were also monitored to observe the ventilation index. Indoor PM_2.5 data were compared categorically with variable air velocities. Those who were using only biomass for cooking in indoor kitchens were recruited in the study. The air pollution exposure burden among the community population is expected to be minimized when the desired ventilation index is optimized and applied in configured kitchens and living rooms. Then, it may attract government policy to accept the ventilation index as a critical parameter for green housing schemes.

Successful Application of Extracorporeal Membrane Oxygenation in an Acute Tonsillitis Patient Complicated with Acute Respiratory Distress Syndrome: A Case Report

Cases of acute tonsillitis, a common disease in the emergency department, are mostly mild and those complicated by severe pneumonia and acute respiratory distress syndrome are rarely reported.

Comparison of nostril sizes of newborn infants with outer diameter of endotracheal tubes

BACKGROUND

Recommendations for endotracheal tube (ETT) size usually refer to the inner diameter (ID). Outer diameters (OD), however, vary greatly between manufacturers, which in some brands might cause difficulties in passing the ETT through the nostrils if choosing the nasal route for intubation. Even though the nostrils are dilatable by an ETT, it might be difficult to pass an ETT through the posterior naris (narrowest point of the nasal passage), if the OD is bigger than the nostrils. Therefore, nostril size may provide some guidance for the appropriate ETT size preventing unsuccessful intubation attempts. This study therefore compares nostril sizes of newborn infants with ODs of ETTs from several manufacturers.

METHODS

This is a subgroup analysis of a prospective observational study, performed in a single tertiary perinatal centre in Germany. The diameter of the nostril of infants born between 34 and 41 weeks´ gestation was measured in 3D images using 3dMDvultus software and compared to the OD of ETT from five different manufacturers.

RESULTS

Comparisons of nostril sizes with ODs of different ETTs were made for 99 infants with a mean (SD) birthweight of 3058g (559) [range: 1850-4100g]. Mean (SD) nostril size was 5.3mm (0.6). The OD of the 3.5mm ETT of different manufacturers ranged from 4.8-5.3mm and was thus larger than the nostril size of 20-46% of late preterm or term infants. Some OD of a 3.0mm ETT were even bigger than the OD of a 3.5mm ETT (e.g. the 3.0mm ETT from Rüsch® has an OD of 5.0mm while the 3.5mm ETT from Portex® has an OD of 4.8mm).

CONCLUSIONS

Clinicians should be aware of the OD of ETTs to reduce unsuccessful intubation attempts caused by ETT sizes not fitting the nasal cavity. Generated data may help to adapt recommendations in future.

TRIAL REGISTRATION

Subgroup analysis of the "Fitting of Commonly Available Face Masks for Late Preterm and Term Infants (CAFF)"-study: NCT03369028, www.ClinicalTrials.gov , December 11, 2017.

Maternal and neonatal risk factors for neonatal respiratory distress syndrome in term neonates in Cyprus: a prospective case-control study

Background

Neonatal respiratory distress syndrome (NRDS) is strongly associated with premature birth, but it can also affect term neonates. Unlike the extent of research in preterm neonates, risk factors associated with incidence and severity of NRDS in term neonates are not well studied. In this study, we examined the association of maternal and neonatal risk factors with the incidence and severity of NRDS in term neonates admitted to Neonatal Intensive Care Unit (NICU) in Cyprus.

Methods

In a prospective, case-control design we recruited term neonates with NRDS and non-NRDS admitted to the NICU of Archbishop Makarios III hospital, the only neonatal tertiary centre in Cyprus, between April 2017–October 2018. Clinical data were obtained from patients’ files. We used univariate and multivariate logistic and linear regression models to analyse binary and continuous outcomes respectively.

Results

During the 18-month study period, 134 term neonates admitted to NICU were recruited, 55 (41%) with NRDS diagnosis and 79 with non-NRDS as controls. In multivariate adjusted analysis, male gender (OR: 4.35, 95% CI: 1.03–18.39, p = 0.045) and elective caesarean section (OR: 11.92, 95% CI: 1.80–78.95, p = 0.01) were identified as independent predictors of NRDS. Among neonates with NRDS, early-onset infection tended to be associated with increased administration of surfactant (β:0.75, 95% CI: − 0.02-1.52, p = 0.055). Incidence of pulmonary hypertension or systemic hypotension were associated with longer duration of parenteral nutrition (pulmonary hypertension: 11Vs 5 days, p < 0.001, systemic hypotension: 7 Vs 4 days, p = 0.01) and higher rate of blood transfusion (pulmonary hypertension: 100% Vs 67%, p = 0.045, systemic hypotension: 85% Vs 55%, p = 0.013).

Conclusions

This study highlights the role of elective caesarean section and male gender as independent risk factors for NRDS in term neonates. Certain therapeutic interventions are associated with complications during the course of disease. These findings can inform the development of evidence-based recommendations for improved perinatal care.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13052-021-01086-5.

Kangaroo mother care practice, knowledge, and perception among NICU nurses in Riyadh, Saudi Arabia

Background

The imapct of Kangaroo Mother Care (KMC) in neonates is positively reported in the literature. However,several challenges hindered the wide-scale application of this practice.

Objectives

To assess the levels of knowledge and competency of kangaroo mother care (KMC) among nurses and to identify the potential barriers to practice.

Methodology

Structured web-based questionnaires were submitted to nurses working at neonatal intensive care units (NICUs) located in Riyadh, Saudi Arabia. The participants were asked to answer 23 questions distributed in four main domains, namely, demographic data, knowledge about KMC, practice levels, and barriers to KMC practice. For answers to the knowledge and barriers to practice domains, the mean scores (standard deviations) were calculated to present participants’ perceptions and beliefs from 1 (strongly disagree) to 5 (strongly agree).

Results

Two hundred nine NICU nurses responded (95.2% females, 89.5% working in a government hospital, 69.9% obtained a Bachelor’s degree). The majority of respondents perceived KMC as promoting maternal-infant bonding (4.47 ± 1.3) and enhancing successful breastfeeding (4.44 ± 0.9), while there were considerable uncertainties about KMC application in infants weighing < 1000 g (2.21 ± 1.2). Most of the nurses encouraged parents to perform KMC (92.8%) and provided sufficient information to optimize practice (90%). However, several barriers were apparent, including fear of accidental extubation, lack of time due to workload, familial reluctance to initiate KMC, and lack of privacy during KMC practice.

Conclusion

There is reasonable knowledge among NICU nurses, and most of them are actively engaged in practice. There is an urgent need to address the reported barriers through the implementation of clear practice guidelines, provision of suitable educational programs, optimization of staff numbers, and financial support for the development of areas conducive to KMC.

Diagnostic Value of Endotracheal Tube-Aspirate Soluble Triggering Receptor Expressed on Myeloid Cells-1 Concentration for Neonatal Ventilator-Associated Pneumonia

Background: Soluble triggering receptor expressed on myeloid cells-1 (sTREM-1) is regarded as a biological marker of infection. We aimed to evaluate the diagnostic value of endotracheal tube (ETT)-sTREM-1 concentration in neonatal ventilator-associated pneumonia (NVAP), to explore the difference of (ETT)-sTREM-1 between preterm and full-term, and to investigate the influence of extrapulmonary infection on (ETT)-sTREM-1 concentration. Methods: In this multicenter, controlled clinical trial of 60 preterm and 33 full-term neonates on mechanical ventilators, we measured concentrations of ETT-aspirate and serum sTREM-1, serum C-reactive protein, and serum procalcitonin, as well as white blood cell count. We initially divided cases into eight groups, based on three categories: preterm of full-term; NVAP or non-NVAP; and extrapulmonary infection present or absent. Groups were compared, and logistic regression analysis and receiver operating characteristic (ROC) analysis was performed to determine diagnostic value. Results: The mean gestational age (± standard deviation) of preterm and full-term neonates was 28.9 ± 2.2 weeks and 39.5 ± 1.7 weeks, respectively, and 32/60 were male. The ETT-aspirate sTREM-1 concentration was higher in NVAP cases than in non-NVAP cases, irrespective of extrapulmonary infection. ROC analysis revealed that ETT-aspirate sTREM-1 concentration had an area under the curve (AUC) of 0.986 and a cutoff value of 228.0 pg/ml (sensitivity, 94.3%; specificity, 96%) in preterm neonates; the same values in full-term neonates were 0.938 and 245.5 pg/ml (sensitivity, 100%; specificity, 93.7%), respectively. The optimal combination of indicators was ETT-aspirate sTREM-1 and serum C-reactive protein concentration. All indicators were present at lower levels on days 8 and 10 of ventilation in neonates who ultimately recovered than in those who did not. Conclusions: ETT-aspirate sTREM-1 and serum C-reactive protein concentrations may be useful for the diagnosis of NVAP.

Caffeine versus aminophylline in combination with oxygen therapy for apnea of prematurity: A retrospective cohort study

The present study was conducted to investigate the clinical significance of caffeine and aminophylline in the treatment of premature infants with apnea under varying conditions of oxygen (O₂) delivery. The clinical data of 120 premature infants with apnea treated with oxygen therapy and either caffeine citrate (20 mg/kg/day; n=77) or aminophylline (10 mg/kg/day; n=43) were retrospectively examined. The therapeutic performance of the drugs after the completion of the treatment was evaluated primarily according to the risk of recurrent episodes of apnea, the changes in the duration and concentration of inhaled O₂ and the incidence of complications. In contrast to aminophylline, caffeine treatment significantly reduced the duration of O₂ inhalation and the inhaled O₂ concentration in the infants treated with mechanical ventilation or O₂ delivery devices (P<0.05). Treatment with caffeine also decreased the incidence of recurrent apnea events and complications in the investigated population (P<0.05 or P<0.01). Caffeine performs better than aminophylline in the treatment of premature infants with apnea under different conditions of O₂ delivery. The therapeutic performance of caffeine is achieved primarily via improving the efficacy of supplemental O₂ and reducing the incidence of complications.

Work of Breathing in Mechanically Ventilated Preterm Neonates

OBJECTIVES

To compare the imposed work of breathing by means of pressure-time product of the diaphragm in newborn infants receiving different modes of mechanical ventilation.

DESIGN

Prospective observational crossover study.

SETTING

Tertiary care neonatal unit.

PATIENTS

Forty preterm newborns (gestational age ≤ 37 wk) in the phase of weaning from mechanical ventilation.

INTERVENTIONS

Participants were ventilated in assist control, synchronized intermittent mandatory ventilation, and intermittent mandatory ventilation mode, in a crossover manner. The combination synchronized intermittent mandatory ventilation-pressure support (SIMV-PS) at 50% (SIMV-PS50) and 75% (SIMV-PS75) of the difference between peak inflating and positive end-expiratory pressure, was also applied in a subset of infants (n = 11). Each mode was maintained for 30 minutes. Transdiaphragmatic pressure was obtained by digital subtraction of esophageal from gastric pressure (both measured using a dual pressure-tipped catheter), and pressure-time product of the diaphragm was computed by integration of transdiaphragmatic pressure over inspiratory time.

MEASUREMENTS AND MAIN RESULTS

The pressure-time product of the diaphragm was 224.2 ± 112.8 in the intermittent mandatory ventilation mode, 165.8 ± 58.8 in the synchronized intermittent mandatory ventilation mode, and 125.5 ± 61.8 cm H2O × s × min in the assist control mode; all values were significantly different to each other (p < 0.0001). The pressure-time product of the diaphragm difference between assist control and intermittent mandatory ventilation, and assist control and synchronized intermittent mandatory ventilation was negatively related to postmenstrual age (regression coefficient, -0.365; p = 0.020 and -0.341; p = 0.031, respectively). In the SIMV-PS subcohort, the pressure-time product of the diaphragm was significantly higher in the intermittent mandatory ventilation mode as compared with assist control (p < 0.0001) or SIMV-PS75 (p = 0.0027), and in the synchronized intermittent mandatory ventilation mode as compared with assist control (p = 0.0301).

CONCLUSIONS

In preterm infants, patient-triggered ventilation modalities result in lower work of breathing than intermittent mandatory ventilation, while the assist control mode is also associated with lower pressure-time product of the diaphragm compared with synchronized intermittent mandatory ventilation. The difference in the imposed diaphragmatic workload between these ventilation modalities was inversely related to postmenstrual age, implying that less mature infants benefit more from assist control-based ventilation strategies.