Innovative practices of ventilatory support with pediatric patients

Effect of ultrasound-guided lung recruitment manoeuvre on perioperative atelectasis during laparoscopy in young infants: A randomised controlled trial

BACKGROUND

Pneumoperitoneum is a risk factor for perioperative atelectasis in infants. This research aimed to investigate whether lung recruitment manoeuvres guided by ultrasound are more effective for young infants (<3 months) during laparoscopy under general anaesthesia.

METHODS

Young infants (<3 months) undergoing general anaesthesia during laparoscopic surgery (>2 h) were randomised to either conventional lung recruitment (control group) or ultrasound-guided lung recruitment (ultrasound group) once per hour. Mechanical ventilation was started with a tidal volume of 8 mL·kg-1, positive end-expiratory pressure of 6 cm H2O and 40% inspired oxygen fraction. Lung ultrasound (LUS) was performed four times (T1 was performed 5 min after intubation and before pneumoperitoneum set, T2 was performed after pneumoperitoneum, T3 was performed 1 min after surgery, and T4 was performed before being discharged from post-anaesthesia care unit [PACU]) in each infant. The primary outcome was the incidence of significant atelectasis at T3 and T4 (defined by LUS consolidation score ≥ 2 in any region).

RESULTS

62 babies were enrolled in the experiment and 60 infants were included in the analysis. Before the recruitment, atelectasis was similar between infants randomised to the control or ultrasound group at T1 (83.3% vs 80.0%; P = 0.500) and T2 (83,3% vs 76.7%; P = 0.519). The incidence of atelectasis at T3 and T4 were lower in the ultrasound group (26.7% and 33.3%), compared with infants randomised to conventional lung recruitment (66.7% and 70%) (P = 0.002; P = 0.004; respectively).

CONCLUSIONS

Ultrasound-guided alveolar recruitment reduced the perioperative incidence of atelectasis in infants <3 months during laparoscopy under general anaesthesia.

ADVERSE EVENTS RELATED TO MECHANICAL VENTILATION IN A PEDIATRIC INTENSIVE CARE UNIT

OBJECTIVE

To identify the prevalence and factors associated with adverse events (AE) related to invasive mechanical ventilation in patients admitted to the Pediatric Intensive Care Unit (PICU) of a tertiary public hospital.

METHODS

This is a cross-sectional study from July 2016 to June 2018, with data collected throughout patients' routine care in the unit by the care team. Demographic, clinical and ventilatory characteristics and adverse events were analysed. The logistic regression model was used for multivariate analysis regarding the factors associated with AE.

RESULTS

Three hundred and six patients were included, with a total ventilation time of 2,155 days. Adverse events occurred in 66 patients (21.6%), and in 11 of those (16.7%) two AE occurred, totalling 77 events (36 AE per 1000 days of ventilation). The most common AE was post-extubation stridor (25.9%), followed by unplanned extubation (16.9%). Episodes occurred predominantly in the afternoon shift (49.3%) and associated with mild damage (54.6%). Multivariate analysis showed a higher occurrence of AE associated with length of stay of 7 days or more (Odds Ratio [OR]=2.6; 95% confidence interval [95%CI] 1.49-4.66; p=0.001).

CONCLUSIONS

The results of the present study show a significant number of preventable adverse events, especially stridor after extubation and accidental extubation. The higher frequency of these events is associated with longer hospitalization.

Pediatric Ventilator Management in the Emergency Department

Pediatric mechanical ventilation is first initiated by emergency physicians when performing active airway management in a critically ill or injured child. When initiating and adjusting mechanical ventilation, the child has unique anatomy and physiology to consider. The EP is the first to respond to ventilator alarm triggers, and the initial medical provider to resuscitate the ventilated pediatric patient who is deteriorating while in the emergency department. This article uses cases to provide a framework to initiate and troubleshoot mechanical ventilation of pediatric patients in the emergency department.

Pediatric Acute Respiratory Distress Syndrome: Fibrosis versus Repair

Clinical and basic experimental approaches to pediatric acute lung injury (ALI), including acute respiratory distress syndrome (ARDS), have historically focused on acute care and management of the patient. Additional efforts have focused on the etiology of pediatric ALI and ARDS, clinically defined as diffuse, bilateral diseases of the lung that compromise function leading to severe hypoxemia within 7 days of defined insult. Insults can include ancillary events related to prematurity, can follow trauma and/or transfusion, or can present as sequelae of pulmonary infections and cardiovascular disease and/or injury. Pediatric ALI/ARDS remains one of the leading causes of infant and childhood morbidity and mortality, particularly in the developing world. Though incidence is relatively low, ranging from 2.9 to 9.5 cases/100,000 patients/year, mortality remains high, approaching 35% in some studies. However, this is a significant decrease from the historical mortality rate of over 50%. Several decades of advances in acute management and treatment, as well as better understanding of approaches to ventilation, oxygenation, and surfactant regulation have contributed to improvements in patient recovery. As such, there is a burgeoning interest in the long-term impact of pediatric ALI/ARDS. Chronic pulmonary deficiencies in survivors appear to be caused by inappropriate injury repair, with fibrosis and predisposition to emphysema arising as irreversible secondary events that can severely compromise pulmonary development and function, as well as the overall health of the patient. In this chapter, the long-term effectiveness of current treatments will be examined, as will the potential efficacy of novel, acute, and long-term therapies that support repair and delay or even impede the onset of secondary events, including fibrosis.

Management Issues in Intensive Care Units for Infants and Children with Heart Disease

Admission of infants and children with cardiac disease to the neonatal (NICU) and pediatric ICU (PICU) is ever increasing in India (30-50 % of all admissions). The commonest indication for admission to the NICU or PICU is acute deterioration of cardiac disease. This includes: acute heart failure, hypercyanotic spells, arrhythmias, pericardial tamponade and sick cardiac neonates who need urgent intervention. Other increasingly frequent indications for ICU admission include heart failure with concomitant chest infection and impending respiratory failure and, severe cyanotic heart disease with various stroke syndromes. It is thus essential that a pediatrician be comfortable with the ICU management of such children and that low cost ICU modalities be utilized in order to reach out to as many children as feasible. It is heartening that there is renewed interest in inexpensive therapies like noninvasive ventilation and therapeutic hypothermia.

Chest Physiotherapy in the Pediatric Intensive Care Unit

Despite widespread practice, there is very little, high-level evidence supporting the indications for and effectiveness of cardiopulmonary/chest physiotherapy (CPT) in critically ill infants and children. Conversely, most studies highlight the detrimental effects or lack of effect of different manual modalities. Conventional CPT should not be a routine intervention in the pediatric intensive care unit, but can be considered when obstructive secretions are present which impact on lung mechanics and/or gaseous exchange and/or where there is the potential for long-term complications. Techniques such as positioning, early mobilization, and rehabilitation have been shown to be beneficial in adult intensive care patients; however, little attention has been paid to this important area of practice in pediatric intensive care units. This article presents a narrative review of chest physiotherapy in pediatric critical illness, including effects, indications, precautions, and specific treatment modalities and techniques.

Pediatric Blunt Thoracic Trauma

Thoracic injury in children deserves special attention because, although it accounts for less than 10% of traumatic injuries in children, there is a significant associated morbidity and mortality. This review discusses the anatomic and physiologic factors resulting in such injury severity with blunt thoracic trauma in children. Specific organ injuries, including most common chest wall injuries, hemo- and pneumothoraces, and pulmonary parenchymal injuries, are discussed, encompassing epidemiology, presentation, diagnosis, and management. Rare injuries including tracheobronchial tree injuries, cardiovascular injuries, esophageal injuries, and diaphragmatic injuries are also briefly discussed.

Optimizing patient-ventilator synchrony during invasive ventilator assist in children and infants remains a difficult task*

OBJECTIVES

To document and compare the prevalence of asynchrony events during invasive-assisted mechanical ventilation in pressure support mode and in neurally adjusted ventilatory assist in children.

DESIGN

Prospective, randomized, and crossover study.

SETTING

Pediatric and Neonatal Intensive Care Unit, University Hospital of Geneva, Switzerland.

PATIENTS

Intubated and mechanically ventilated children, between 4 weeks and 5 years old.

INTERVENTIONS

Two consecutive ventilation periods (pressure support and neurally adjusted ventilatory assist) were applied in random order. During pressure support, three levels of expiratory trigger setting were compared: expiratory trigger setting as set by the clinician in charge (PSinit), followed by a 10% (in absolute values) increase and decrease of the clinician's expiratory trigger setting. The pressure support session with the least number of asynchrony events was defined as PSbest. Therefore, three periods were compared: PSinit, PSbest, and neurally adjusted ventilatory assist. Asynchrony events, trigger delay, and inspiratory time in excess were quantified for each of them.

MEASUREMENTS AND MAIN RESULTS

Data from 19 children were analyzed. Main asynchrony events during PSinit were autotriggering (3.6 events/min [0.7-8.2]), ineffective efforts (1.2/min [0.6-5]), and premature cycling (3.5/min [1.3-4.9]). Their number was significantly reduced with PSbest: autotriggering 1.6/min (0.2-4.9), ineffective efforts 0.7/min (0-2.6), and premature cycling 2/min (0.1-3.1), p < 0.005 for each comparison. The median asynchrony index (total number of asynchronies/triggered and not triggered breaths ×100) was significantly different between PSinit and PSbest: 37.3% [19-47%] and 29% [24-43%], respectively, p < 0.005). With neurally adjusted ventilatory assist, all types of asynchrony events except double-triggering and inspiratory time in excess were significantly reduced resulting in an asynchrony index of 3.8% (2.4-15%) (p < 0.005 compared to PSbest).

CONCLUSIONS

Asynchrony events are frequent during pressure support in children despite adjusting the cycling off criteria. Neurally adjusted ventilatory assist allowed for an almost ten-fold reduction in asynchrony events. Further studies should determine the clinical impact of these findings.

Surfactant therapy for acute lung injury and acute respiratory distress syndrome

This article examines exogenous lung surfactant replacement therapy and its usefulness in mitigating clinical acute lung injury (ALI) and the acute respiratory distress syndrome (ARDS). Surfactant therapy is beneficial in term infants with pneumonia and meconium aspiration lung injury, and in children up to age 21 years with direct pulmonary forms of ALI/ARDS. However, extension of exogenous surfactant therapy to adults with respiratory failure and clinical ALI/ARDS remains a challenge. This article reviews clinical studies of surfactant therapy in pediatric and adult patients with ALI/ARDS, focusing on its potential advantages in patients with direct pulmonary forms of these syndromes.

Complications of mechanical ventilation in the pediatric population

BACKGROUND

Mechanical ventilation (MV) strategies are continuously evolving in an effort to minimize adverse events. The objective of this study was to determine the complications associated with MV in children.

STUDY DESIGN

Prospective observational study. Over a period of 10 consecutive months, 150 patients (median age 0.8 years, IQR 4.4, 59% male) were enrolled in this study.

RESULTS

The median duration of MV was 3.1 days (IQR 3.9). A total of 85 complications were observed in 60 (40%) patients (114 complications per 1,000 ventilation days). 16.7% of patients developed atelectasis, 13.3% post-extubation stridor, 9.3% failed extubation, 2.0% pneumothorax, 3.3% accidental extubation, 2.7% nasal or perioral tissue damage and 1.9% ventilator associated pneumonia. Atelectasis occurred most often in the left lower lobe (36%) or in the right upper lobe (26%). The incidence of atelectasis in children <1 year of age was 12% (31 episodes per 1,000 days of ventilation) compared to 18% (57 episodes per 1,000 days of ventilation) in children ≥ 1 year of age (P < 0.05). Patients that failed extubation were ventilated for a median of 8.5 (IQR 8.8) days compared to 2.9 days (IQR, 3.8) in patients that were successfully extubated (P < 0.01). The absence of an air leak prior to extubation did not correlate with failed extubation. Accidental extubation was limited to orally intubated patients.

CONCLUSION

MV complications occurred in 40% of patients and most often consisted of atelectasis and post-extubation stridor. Further studies are needed to examine associated risk factors and strategies to reduce their occurrence.

Pressure characteristics of mechanical ventilation and incidence of pneumothorax before and after the implementation of protective lung strategies in the management of pediatric patients with severe ARDS

OBJECTIVE

To compare pressure characteristics of mechanical ventilation and their impact on pediatric patients with severe ARDS in the pre-protective lung strategy (PLS) and post-PLS eras.

METHODS

Medical records of 33 patients admitted to our pediatric ICU with ARDS from 1992 through 1994 (pre-PLS) and 52 patients with ARDS admitted from 2000 through 2003 (post-PLS) were retrospectively reviewed.

RESULTS

Patient age and gender distribution were identical in both eras. Fifty-five percent of the patients in the pre-PLS era had pneumothorax, compared to 17% in the post-PLS era (p < 0.05). Overall mortality rates for patients in the pre-PLS and post-PLS eras were 42% and 25%, respectively (p = 0.09; not significant). Mean duration of exposure to peak inspiratory pressure (PIP) values > 40 cm H2O was significantly longer in the pre-PLS era than in the post-PLS era. Pre-PLS patients with pneumothorax received mean maximum PIP of 72 +/- 17 cm H2O, mean maximum positive end-expiratory pressure (PEEP) of 20 +/- 5 cm H2O, and maximum mean airway pressure (MAP) of 46 +/- 8 cm H2O, while patients in the post-PLS era required mean maximum PIP of 42 +/- 2 cm H2O, mean maximum PEEP of 14 +/- 2 cm H2O, and maximum MAP of 30 +/- 6 cm H2O, respectively (p < 0.05 for all pressure parameters). There were no significant differences in mechanical ventilation pressure characteristics among patients who did not have pneumothorax during their course of management in both eras.

CONCLUSIONS

A significantly more aggressive use of ventilator pressure characteristics distinguished the pre-PLS era from the post-PLS era, and was found to be associated with a markedly higher incidence of pneumothorax. Outcome in both eras did not differ significantly, presumably due to insufficient statistical power.

The lung and pediatric trauma

Thoracic trauma is relatively frequent in children and causes considerable mortality. This is mainly due to the multiorganic nature of the trauma. The lung is more often affected even in the absence of rib fractures because of the considerable pliability of the chest wall that allows direct transfer of energy to this organ. Injuries to the heart, the aorta, the esophagus, and the diaphragm are rare. Lung contusion and laceration cause parenchymal hemorrhage and consolidation sometimes accompanied by pneumothorax and/or hemothorax. Tracheobronchial disruption is rare but life-threatening. Most traumatic lung injuries may be treated with rest, respiratory support, and eventually intercostal drainage. Large hemorrhage may require thoracotomy, and persistent pneumothorax (indicative of tracheobronchial disruption) may require intubation with fiberoptic bronchoscopic assistance and eventually reparative or ablative surgery. Adult respiratory distress syndrome is very rarely seen in children with thoracic trauma, but it remains highly lethal.

A recruitment manoeuvre performed after endotracheal suction does not increase dynamic compliance in ventilated paediatric patients: a randomised controlled trial

QUESTION

Does a recruitment manoeuvre after suctioning have any immediate or short-term effect on ventilation and gas exchange in mechanically-ventilated paediatric patients?

DESIGN

Randomised controlled trial with concealed allocation, assessor blinding, and intention-to-treat analysis.

PARTICIPANTS

Forty-eight paediatric patients with heterogeneous lung pathology. Fourteen patients were subsequently excluded from analysis due to large leaks around the endotracheal tube.

INTERVENTION

The experimental group received a single standardised suctioning procedure followed five minutes later by a standardised recruitment manoeuvre. The control group received only the single suctioning procedure.

OUTCOME MEASURES

Measurements of ventilation (dynamic lung compliance, expiratory airway resistance, mechanical and spontaneous expired tidal volume, respiratory rate) and gas exchange (transcutaneous oxygen saturation) were recorded, on three occasions before and on two occasions after the recruitment manoeuvre, using a respiratory profile monitor.

RESULTS

There was no difference between the experimental and the control group in dynamic compliance, expired airway resistance, or oxygen saturation either immediately after the recruitment manoeuvre, or after 25 minutes. The experimental group decreased mechanical expired tidal volume by 0.3 ml/kg (95% CI 0.1 to 0.6), increased spontaneous expired tidal volume by 0.3 ml/kg (95% CI 0.0 to 0.6), and increased total respiratory rate by 3 bpm (95% CI 1 to 4) immediately after the recruitment manoeuvre compared with the control group, but these differences disappeared after 25 minutes.

CONCLUSION

There is insufficient evidence to support performing recruitment manoeuvres after suctioning infants and children.

Have changes in ventilation practice improved outcome in children with acute lung injury?

OBJECTIVES

To describe the changes that have occurred in mechanical ventilation in children with acute lung injury in our institution over the last 10-15 yrs and to examine the impact of these changes, in particular of the delivered tidal volume on mortality.

DESIGN

Retrospective study.

SETTING

University-affiliated children's hospital.

PATIENTS

The management of mechanical ventilation between 1988 and 1992 (past group, n = 79) was compared with the management between 2000 and 2004 (recent group, n = 85).

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

The past group patients were ventilated with a significantly higher mean tidal volume (10.2 +/- 1.7 vs. 8.1 +/- 1.4 mL.kg actual body weight, p < .001), lower levels of positive end-expiratory pressure (6.1 +/- 2.7 vs. 7.1 +/- 2.4 cm H2O, p = .007), and higher mean peak inspiratory pressure (31.5 +/- 7.3 vs. 27.8 +/- 4.2 cm H2O, p < .001) than the recent group patients. The recent group had a lower mortality (21% vs. 35%, p = .04) and a greater number of ventilator-free days (16.0 +/- 9.0 vs. 12.6 +/- 9.9 days, p = .03) than the past group. A higher tidal volume was independently associated with increased mortality (odds ratio 1.59; 95% confidence interval 1.20, 2.10, p < .001) and reduction in ventilation-free days (95% confidence interval -1.24, -0.77, p < .001).

CONCLUSIONS

The changes in the clinical practice of mechanical ventilation in children in our institution reflect those reported for adults. In our experience, mortality among children with acute lung injury was reduced by 40%, and tidal volume was independently associated with reduced mortality and an increase in ventilation-free days.

The Air-Leak Test Is Not a Good Predictor of Postextubation Adverse Events in Children Undergoing Cardiac Surgery

OBJECTIVE

The air-leak test is recommended as a method of assessing the appropriate size of an uncuffed endotracheal tube (ETT) in children. The authors' primary objective was to determine whether the air-leak test would predict adverse events and reintubations after the removal of the ETT in children who have undergone cardiac surgery.

DESIGN

Prospective, observational, clinical study.

SETTING

University tertiary care hospital.

PATIENTS

Ninety-four children <10 years of age undergoing elective cardiac surgery requiring cardiopulmonary bypass surgery.

INTERVENTIONS

The attending anesthesiologist assessed air-leak pressure after intubation in the operating room (OR). In addition, the air-leak test was performed in 42 patients before extubation in the pediatric intensive care unit (PICU). The incidence of adverse events and the number of failed extubations were recorded after removal of the ETT.

MEASUREMENTS AND MAIN RESULTS

Eleven of the 94 patients were excluded from the study. Four (4.3%) of the patients died in the PICU before extubation, and 7 patients were excluded for other reasons. The median age of the 83 children was 0.9 years (range 0.01-9.6 years). The total incidences of postextubation adverse events and failed extubations were 30.1% and 8.4%, respectively. An audible air leak < or =25 cmH(2)O airway pressure during the OR phase or before removal of the ETT during the PICU recovery phase had no significant predictive value for the incidence of adverse events (p = 0.63) or reintubations (p = 1.0). The patients undergoing simple and complete operations compared with more complex and incomplete operations had significantly fewer postextubation adverse events (p = 0.03). Neonates did not have a higher risk for postextubation adverse events (p = 0.64) or reintubations (p = 0.26) than older children.

CONCLUSION

The air-leak test did not predict an increased risk for postextubation adverse events and reintubations in children undergoing elective congenital heart surgery.

Optimally fitted tracheal tubes decrease the probability of postextubation adverse events in children undergoing general anesthesia

BACKGROUND

The air leak test is recommended for assessing the appropriate size of an uncuffed tracheal tube (TT) in children. Our objectives were to determine whether there is a certain threshold air leak value beyond which a higher risk for adverse events after removal of TT can be predicted and to define other risk factors related to extubation.

METHODS

We enrolled 234 cases ranging from newborn to 9 years of age requiring tracheal intubation for elective or emergency surgery. General anesthesia was induced by a mask or intravenously. The TT size was calculated using the formula: [age (years)/4] + 4.5. After the induction of anesthesia, the patient's trachea was intubated and the correct position was confirmed. The attending anesthetist assessed the leak pressure. Incidences of adverse events (prolonged or barking cough, obstructed or prolonged inspiration or expiration, subcostal and sternal retractions, arterial desaturation, or laryngospasm) were recorded after removal of TT.

RESULTS

Ten patients were excluded from the study. A total of 218 children underwent 224 operations under general anesthesia. Children who had an absent air leak at 25 cmH(2)O pressure had 2.8 times more adverse events during emergence from anesthesia than those with an audible air leak. Adverse events after the removal of TT were 3.7 times more likely to occur in children whose anesthesia was provided by a less experienced anesthesia trainee.

CONCLUSIONS

Adverse events after removal of TT were more likely to occur in children with an absent air leak at 25 cmH(2)O pressure and in children whose anesthesia was provided by a less experienced anesthetist.

One lung ventilation in infants and children: experience with Marraro double lumen tube

BACKGROUND

Our objective was to evaluate the efficacy of selective bronchial intubation and independent lung ventilation during thoracic surgery in children up to 3 years, using a double lumen tube.

METHODS

We studied retrospective (cases 1-6) and prospective cases (7-17) between January 1996 and December 2000 at the All India Institute of Medical Sciences, New Delhi, India and at Fatebenefratelli and Ophthalmiatric Hospital, Milan, Italy. Seventeen children, 1 day to 3 years of age and weighing 2.7-12 kg, were submitted to thoracic surgery for a variety of surgical conditions. Anesthesia was conducted as usual in this type of patient and selective intubation was performed using a double lumen tube (Marraro Pediatric double lumen tube). During the operation one lung ventilation was applied and at the end of surgery the collapsed lung was reexpanded independently from the contralateral lung.

RESULTS

Six children remained intubated with a double lumen tube for between 8 and 48 h and one (case no. 11) with a single lumen tube for 24 h, while 10 of the older children were extubated on the table. No serious complications during or after surgery were noted and after extubation all the children recovered completely without sequelae.

CONCLUSIONS

The double lumen tube appears to be very effective in allowing one lung ventilation in this age group during thoracic surgery.

[Mechanical ventilation in pediatrics (III). Weaning, complications and other types of ventilation. High-frequency ventilation]

In the era of lung-protective ventilation strategies, high frequency oscillatory ventilation (HFOV) has attracted renewed interest and its use has dramatically increased in neonatal and pediatric intensive care units. HFOV is able to reduce ventilator-induced lung injury by limiting the incidence of volutrauma, atelectrauma, barotrauma and biotrauma. During HFOV, adequate oxygenation and ventilation is achieved by using low tidal volumes and small pressure swings at supraphysiologic frequencies. Unlike other high-frequency ventilation modes, HFOV has an active expiration phase. HFOV constitutes a safe and successful ventilation mode for managing pediatric patients with respiratory insufficiency refractory to optimized conventional mechanical ventilation and provides better results when initiated early. However, the elective use of HFOV requires further studies to identify its benefits over conventional modes of mechanical ventilation and to support its routine use as a first line therapy. In the present article, the Respiratory Working Group of the Spanish Society Pediatric Critical Care reviews the main issues in the pediatric application of HFOV. In addition, a general practical protocol and specific management strategies, as well as the monitoring, patient care and other special features of the use of HFOV in the pediatric setting, are discussed.