Treatment of giant pulmonary interstitial emphysema by ipsilateral bronchial occlusion with a Swan-Ganz catheter

BACKGROUND

Unilateral giant pulmonary interstitial emphysema (PIE) can be seen as a complication of chronic ventilation in extremely low-birth-weight babies. Many can be managed by conventional pulmonary care which includes positioning, suctioning, chest physiotherapy, gentle conventional ventilation and high-frequency ventilation. Some may need invasive procedures such as lung puncture, pleurotomies and excisional surgery. This is the group in which single-lung ventilation may be beneficial and circumvent the need for an invasive procedure.

OBJECTIVE

We describe the technique of single-lung ventilation using a Swan-Ganz catheter to block the main stem bronchus on the diseased side in air-leak syndromes.

MATERIALS AND METHODS

A retrospective chart review was done on 17 newborns undergoing single-lung ventilation using this technique at the Children's Hospital of New York, Columbia University, from 1986 to 2000.

RESULTS

The technique was successful in the management of severe, neonatal unilateral lung disease not responsive to conventional modes of therapy in all but two neonates as seen by a significant improvement in pH and a decrease in PaCO(2) levels. In one neonate malpositioning of the Swan-Ganz catheter balloon could have contributed to the development of pneumothorax.

CONCLUSION

The described technique of single-lung ventilation provides a safe, minimally invasive and economically feasible method of management of unilateral giant PIE in newborns not responsive to conventional modes of therapy with minimal complications.

Variables associated with the early failure of nasal CPAP in very low birth weight infants

OBJECTIVE

To identify risk factors and neonatal outcomes associated with the early failure of "bubble" nasal continuous positive airway pressure (CPAP) in very low birth weight (VLBW) infants with respiratory distress syndrome (RDS).

STUDY DESIGN

Following resuscitation and stabilization at delivery, a cohort of 261 consecutively inborn infants (birth weight < or = 1250 g) was divided into three groups based on the initial respiratory support modality and outcome at 72 hours of age: "ventilator-started" group, "CPAP-failure" group, and "CPAP-success" group.

RESULTS

CPAP was successful in 76% of infants < or = 1250 g birth weight and 50% of infants < or = 750 g birth weight. In analyses adjusted for postmenstrual age (PMA) and small for gestational age (SGA), CPAP failure was associated with need for positive pressure ventilation (PPV) at delivery, alveolar-arterial oxygen tension gradient (A-a DO2) >180 mmHg on the first arterial blood gas (ABG), and severe RDS on the initial chest x-ray (adjusted odds ratio [95% CI] = 2.37 [1.02, 5.52], 2.91 [1.30, 6.55] and 6.42 [2.75, 15.0], respectively). The positive predictive value of these variables ranged from 43% to 55%. In analyses adjusted for PMA and severe RDS, rates of mortality and common premature morbidities were higher in the CPAP-failure group than in the CPAP-success group.

CONCLUSION

Although several variables available near birth were strongly associated with early CPAP failure, they proved weak predictors of failure. A prospective controlled trial is needed to determine if extremely premature spontaneously breathing infants are better served by initial management with CPAP or mechanical ventilation.

Inhaled nitric oxide and gentle ventilation in the treatment of pulmonary hypertension of the newborn--a single-center, 5-year experience

OBJECTIVE

To evaluate the effect of inhaled nitric oxide (INO) in pulmonary hypertension of the newborn (PH) in a single center over 5 years using gentle ventilation (GV), without hyperventilation or induced alkalosis.

METHODS

Data from 229 consecutive infants with PH of varied etiology treated with INO and GV, and from 67 infants with meconium aspiration syndrome (MAS) and primary PH (PPHN) treated with GV alone were reviewed over a 5-year period (86% outborn). INO was initiated at 25 ppm when PH and severe hypoxemia persisted despite maximal optimal ventilation. Hyperventilation or systemic alkalosis were not attempted.

RESULTS

Mean duration of ventilation was 9.9 +/- 14 days (median 6.5 days). Average mean airway pressure (MAP) dropped from 17.7 +/- 4.3 cm H(2)O at the referral hospital to 13.2 +/- 2.5 cm H(2)O (p < 0.001) following admission to our unit using conventional settings and GV, before starting INO. Mean oxygenation index (OI) dropped from 46.8 +/- 24.5 to 22.7 +/- 21.4 within 24 hours of INO therapy (p < 0.001). Infants with higher baseline pH and lower baseline OI responded better to INO (p < 0.02). Overall survival was 72%. Patients with MAS and PPHN had the best response, 92% survived and there was a 46% reduction in need for extracorporeal membrane oxygenation (ECMO) compared to historical pre-INO period controls (23.9% vs. 12.8%, p < 0.01). In the infants treated with GV alone, the MAP dropped from 17.2 +/- 4.3 cm H2O at the referral hospital to 12.6+/-2.4 after GV was started in our unit.

CONCLUSIONS

We conclude that INO is an effective and well-tolerated therapy for PH in infants receiving GV.

Subcutaneous emphysema and pneumomediastinum as presenting manifestations of neonatal tracheal injury

Neonatal tracheal injury/perforation is an uncommon complication of traumatic deliveries or endotracheal intubation. We present a case of neonatal tracheal injury following delivery at term that presented with subcutaneous emphysema and pneumomediastinum before any attempt at intubation. The clinical course, treatment, and outcome are described.

Congenital diaphragmatic hernia in 120 infants treated consecutively with permissive hypercapnea/spontaneous respiration/elective repair

BACKGROUND/PURPOSE

Poor prognosis (approximately 50% survival rate and significant morbidity) traditionally has been associated with congenital diaphragmatic hernia (CDH). The authors reviewed a single institution experience and challenged conventional wisdom in the context of a care strategy based on permissive hypercapnea/spontaneous respiration/elective repair.

METHODS

From August 1992 through February 2000, all infants with CDH and (1) respiratory distress requiring mechanical ventilation, (2) in-born or (3) transferred preoperatively within hours of birth are reported. All respiratory care strategy used permissive hypercapnea/spontaneous respiration and combined with elective repair. Arterial blood gas values and concomitant ventilator support were recorded. Outcome markers were (1) need for extracorporeal membrane oxygenation ECMO, (2) discharge to home, (3) supplemental oxygen need at discharge, and (4) influence of non-ECMO ancillary therapies (surfactant, nitric oxide, high-frequency oscillatory ventilation).

RESULTS

One hundred twenty consecutive infants were reviewed. Overall survival rate was 75.8%, but, excluding 18 of 120 not treated (6 lethal anomalies, 10 overwhelming pulmonary hypoplasia, 3 prerepair ECMO-related neurocomplications), 84.4% survived to discharge. A total of 67/120 were inborn. Non-ECMO ancillary treatments had no impact on survival rate. ECMO was used in 13.3%. Surgery was transabdominal; prosthetics were used in 7%. Tube thoracostomy was rare. Every inborn patient (n = 11) requiring a chest tube for pneumothorax died. Respiratory support before surgery was peak inspiratory pressure (PIP), 22, FIO(2),.43 with PaO(2), 66 torr; PaCO(2), 41 torr; and pH, 7.32. The survivors discharged on oxygen (n = 2) died at 4 and 7 months.

CONCLUSIONS

The majority of infants with life-threatening CDH treated with permissive hypercapnea/spontaneous respiration/elective surgery survive to discharge with minimal pulmonary morbidity.

Randomised controlled trial of thiopental for intubation in neonates

AIMS

To determine the effects of premedication with thiopental on heart rate, blood pressure, and oxygen saturation during semi-elective nasotracheal intubation in neonates.

METHODS

A randomised, placebo controlled, non-blinded study design was used to study 30 neonates (mean birthweight 3.27 kg) requiring semi-elective nasotracheal intubation. The babies were randomly allocated to receive either 6 mg/kg of thiopental (study group) or an equivalent volume of physiological saline (control group) one minute before the start of the procedure. Six infants were intubated primarily and 24 were changed from orotracheal to a nasotracheal tube. The electrocardiogram, arterial pressure wave, and transcutaneous oxygen saturation were recorded continuously 10 minutes before, during, and 20 minutes after intubation. Minute by minute measurements of heart rate, heart rate variability, mean blood pressure (MBP) and transcutaneous oxygen saturation (SpO(2)) were computed. The differences for all of these between the baseline measurements and those made during and after intubation were determined. Differences in the measurements made in the study and the control groups were compared using Student's t test.

RESULTS

During intubation, heart rate increased to a greater degree (12.0 vs -0.5 beats per minute, p < 0.03) and MBP increased to a lesser degree (-2.9 vs 4.4 mm Hg; p < 0.002) in the infants who were premedicated with thiopental. After intubation only the changes in MBP differed significantly between the two groups (-3.8 vs 4.6 mm Hg; p < 0.001). There were no significant changes in the oxygen saturation between the two groups during or after intubation. The time taken for intubation was significantly shorter in the study group (p < 0.04).

CONCLUSIONS

The heart rate and blood pressure of infants who are premedicated with thiopental are maintained nearer to baseline values than those of similar infants who receive no premedication. Whether this lessening of the acute drop in the heart rate and increase in blood pressure typically seen during intubation of unmedicated infants is associated with long term advantages to the infants remains to be determined.

Spontaneous correction of the malpositioned percutaneous central venous line in infants

Malpositioning of the percutaneously placed central venous line (PCVL) or percutaneously inserted central catheter (PICC) in infants is not a rare occurrence. It has been occasionally observed that these lines spontaneously correct themselves. This prospective study was done to study the incidence of malposition and spontaneous correction. Using a modification of the standard method, 187 catheters were placed with 98.9 % success. Seven of these were initially malpositioned. All seven corrected themselves within a day when left in and used as a peripheral intravenous line. In many centers malpositioned catheters are taken out and replaced, which imposes great stress on the critically ill infant. Our study suggests that to avoid this stress the catheter should be left in place, since spontaneous correction may occur.

Continuous positive airway pressure (CPAP)

Progress in neonatal intensive care is closely linked to improvements in the management of respiratory failure in small infants. This applies to the care of the preterm infants with immature lungs, and also to treatment of the preterm or full term infants with specific diseases that are associated with respiratory failure. Respiratory distress of the newborn continues to account for significant morbidity in the intensive care unit. The spectrum of disease ranges from mild distress to severe respiratory failure requiring varying degrees of support. The current modalities of ventilatory assistance range from the more benign continuous positive airway pressure (CPAP) to conventional mechanical ventilation, and on to high frequency ventilation. It is a reasonable supposition that the type of ventilatory assistance provided to these infants should be graded according to the severity of the disease. However, the principal objective in selecting the mode of respiratory support should be to use a modality which results in minimal volo- or barotrauma to the infant. The following detailed description on CPAP explains its physiological effects, delivery system, indications for use, application, maintenance, and associated complications. The equipment described is simple to use, has a greater cost benefit, and has a more universal application, which is of help to smaller units including those in the developing parts of the world. We have also included our institutional clinical experience of CPAP usage in very low birth weight infants from the periods before and after commercial availability of surfactant in the United States.

Weaning strategy with inhaled nitric oxide treatment in persistent pulmonary hypertension of the newborn

AIM

To determine if infants who had become dependent on inhaled nitric oxide treatment could be successfully weaned off it if FIO2 was increased briefly during withdrawal.

METHODS

Sixteen infants admitted for conditions associated with increased pulmonary vascular resistance responded well to inhaled nitric oxide treatment with a significant increase in PaO2 (maximum inhaled nitric oxide given 25 ppm). Weaning from inhaled nitric oxide in 5 ppm decrements was initiated once the FIO2 requirement was less than 0.5. When patients were stable on 5 ppm of inhaled nitric oxide, the gas was then discontinued. If a patient showed inhaled nitric oxide dependence-that is, oxygen saturation fell by more than 10% or below 85%-inhaled nitric oxide was reinstated at 5 ppm and the patient allowed to stabilise for 30 minutes. At this time, FIO2 was increased by 0.40 and weaning from inhaled nitric oxide was attempted again.

RESULTS

Nine infants were successfully weaned on the first attempt. The seven infants who failed the initial trial were all successfully weaned following the increase in FIO2. After successful weaning, FIO2 was returned to the pre-weaning level in mean 148(SD 51) minutes and inhaled nitric oxide was never reinstated.

CONCLUSION

Infants showing inhaled nitric oxide dependency can be successfully weaned by increasing FIO2 transiently.

Preoperative cardiorespiratory trends in infants with congenital diaphragmatic hernia

The objective of this study was to determine the cardiovascular and pulmonary adaptations of infants with congenital diaphragmatic hernia (CDH) from birth until delayed surgery through the use of continuous monitoring. Continuous cardiovascular (HR, heart rate variability [HR-SD], BP, blood pressure variability [BP-SD], and oxygen saturation) and ventilatory (minute volume, airway pressure, and effective compliance) measurements were made on-line, using a computerized whole-body plethysmograph-incubator (Vital-trends, VT1000), in nine ventilated infants with CDH. Data collection commenced at birth and continued until surgery. Minute mean values for each variable were recorded. Hourly means were computed from the minute means, averaged across infants each hour over the first 50 hours of life, and regressed against postnatal age. Results showed a significant increase in BP (P < .01), BP-SD (P < .05), HR-SD (P < .04), and pH (P < .02) versus postnatal age, and a decrease in PaCO2 (P < .04), FIO2 (P < .001), Alveolar-arterial oxygen gradient (P < .003), and oxygenation index (P < .002). Infants with CDH show cardiopulmonary trends over the first 2 days of life that are qualitatively similar to those of normal newborn infants. Deviation from these idealized patterns may identify an infant who is not responding satisfactorily to the given therapy and who may require alternative treatment modalities.

Congenital diaphragmatic hernia: survival treated with very delayed surgery, spontaneous respiration, and no chest tube

This report suggests that stabilization of the intrauterine to extrauterine transitional circulation combined with a respiratory care strategy that avoids pulmonary overdistension, takes advantage of inherent biological cardiorespiratory mechanics, and very delayed surgery for congenital diaphragmatic hernia results in improved survival and decreases the need for extracorporeal membrane oxygenation (ECMO). This retrospective review of a 10-year experience in which the respiratory care strategy, ECMO availability, and technique of surgical repair remained essentially constant describes the evolution of this method of management of congenital diaphragmatic hernia.

Effect of blood pressure cuffs on neonatal circulation: their potential application to newborns with persistent pulmonary hypertension

The contribution of vasoactive pharmacologic agents to the care of the infant with primary pulmonary hypertension of the newborn (PPHN) is hampered by their limited ability to act selectively on different vascular beds. In contrast, blood pressure (BP) cuffs decrease flow and increase resistance only in the extremities around which they are applied. They therefore offer a means of increasing systemic vascular resistance without affecting pulmonary vascular resistance, a hemodynamic effect that may be particularly desirable among PPHN patients receiving vasodilators. We studied the effect of BP cuffs on the circulation of nine healthy neonates and three infants with severe PPHN. Among the healthy neonates, inflation of the cuffs to 20 mmHg had no discernible hemodynamic effect. Inflation to systolic pressures, however, caused the left ventricular preejection period to increase from 36 +/- 9 ms to 45 +/- 10 ms, the end-diastolic dimension to increase from 1.80 +/- 0.16 cm to 1.92 +/- 0.16 cm, and the cardiac output to fall to 87 +/- 12% of baseline (all p < 0.05)--changes indicative of an increase in systemic vascular resistance. Application of BP cuffs to the patients with PPHN was associated with 10-25 mmHg increases in transcutaneous arterial oxygen tensions. Administration of tolazoline to these patients while the cuffs were inflated resulted in additional 10-20 mmHg increases and did not precipitate hypotension. These observations suggest that BP cuffs can play a useful role in the management of patients with PPHN.

Hearing and neurodevelopmental outcome in survivors of persistent pulmonary hypertension of the newborn

Thirty-four infants who had a diagnosis of severe persistent pulmonary hypertension of the newborn at birth (alveolar-arterial oxygen difference greater than 600) were treated without paralysis or hyperventilation to induce alkalosis. All survived. Twenty-seven of these 34 eligible infants (79%) underwent neurologic, intelligence, and audiologic testing between 10 months and 6 years of age. Children who were younger than 1 year of age at the initial hearing test were retested after they reached 2 years of age. The average IQ was within the normal range (mean = 96.23). None had sensorineural hearing loss. Severe neurologic abnormalities were seen in 4 children, 3 of whom had been severely asphyxiated at birth (determined by biochemical criteria). Mild neurologic abnormalities were observed in 5 children. Two infants had bronchopulmonary dysplasia because they required supplemental oxygen for 29 and 66 days, respectively, and had abnormal chest roentgenograms; 1 patient takes intermittent doses of albuterol (Ventolin) and neither currently requires supplemental oxygen. This study of 27 infants with severe persistent pulmonary hypertension of the newborn suggests that conservative management without induced alkalosis or respiratory paralysis is accompanied by no sensorineural hearing loss and a good neurologic outcome.

Benign gaseous distension of the bowel in premature infants treated with nasal continuous airway pressure: a study of contributing factors

Continuous positive airway pressure (CPAP) administered as a mixture of oxygen and compressed air via nasal prongs has dramatically improved survival rates and lessened the frequency of barotrauma and bronchopulmonary dysplasia in the premature infant with respiratory distress syndrome. Associated with the increased use of nasal CPAP has been the development of marked bowel distension (CPAP belly syndrome), which occurs as the infant's respiratory status improves and the baby becomes more vigorous. To identify contributing factors, we prospectively compared 25 premature infants treated with nasal CPAP with 29 premature infants not treated with nasal CPAP. Infants were followed up for development of distension, defined clinically as bulging flanks, increased abdominal girth, and visibly dilated intestinal loops. We evaluated birth weight, weight at time of distension, method of feeding (oral, orogastric tube), and treatment with nasal CPAP and correlated these factors with radiologic findings. Of the infants who received nasal CPAP therapy, gaseous bowel distension developed in 83% (10/12) of infants weighing less than 1000 g, but in only 14% (2/14) of those weighing at least 1000 g. Only 10% (3/29) of infants not treated with nasal CPAP had distension, and all three weighed less than 1000 g. Presence of sepsis and method of feeding did not correlate with occurrence of distension. Neither necrotizing enterocolitis nor bowel obstruction developed in any of the patients with a diagnosis of CPAP belly syndrome. Our study shows that nasal CPAP, aerophagia, and immaturity of bowel motility in very small infants were the major contributors to the development of benign gaseous bowel distension.

Right pneumonectomy syndrome: a lethal complication of lung resection in a newborn with cystic adenomatoid malformation

A newborn girl underwent a right pneumonectomy for cystic adenomatoid malformation. She subsequently developed compression of the trachea and left mainstem bronchus by a combination of aortic arch, pulmonary artery, and ductus arteriosus. She died while planning aortic suspension, and the anatomic relationships were confirmed by autopsy. This problem is potentially treatable by a variety of means.

Experience with percutaneous indwelling peripheral arterial catheterization in neonates

We present an experience with indwelling peripheral arterial catheters in preterm and term neonates. During a 12-month interval, 158 peripheral arterial lines were inserted in 115 infants. Eighty-eight infants required a single line while 27 infants required more than one line. Ninety-one catheters (57.6%) were electively removed, and 67 (42.4%) had to be discontinued prematurely. Vessels used included 110 radial arteries (69.6%), 27 posterior tibial arteries (17.1%), and 21 temporal arteries (13.3%). There were only two major complications (1.27%), both related to infections. The technique is described in detail. In our experience, with appropriate precaution, peripheral arterial cannulation has been a safe and reliable alternative to umbilical arterial catheterization.

Retrocardiac pneumomediastinum in association with tracheal and esophageal perforations

Retrocardiac pneumomediastinum was encountered in two premature infants; one had a tracheal perforation and one an esophageal perforation. Contrast studies showed communication between the sites of perforation and the retrocardiac air. Clinical signs suggestive of such perforation include abnormal course of tubes on plain chest films and bloody aspirates.

Management of infants with severe respiratory failure and persistence of the fetal circulation, without hyperventilation

The successful management of 15 infants suffering from persistence of fetal pulmonary circulation and in severe respiratory failure is presented. The treatment regimen focused on minimizing barotrauma. Infants were intubated nasotracheally and ventilated with intermittent mandatory ventilation. Peak inspiratory pressures were determined by the clinical assessment of chest excursion. Ventilator settings and fractional inspiratory oxygen (FiO2) were selected to maintain a PaO2 between 50 and 70 mm Hg; PaCO2 was not a controlling parameter and was allowed to increase as high as 60 mm Hg. Hyperventilation and muscle relaxants were not used. High ventilator rate was used in ten infants who required high inspiratory pressure to maintain chest excursion, with a favorable response in five. Tolazoline was given to 14 infants of whom ten showed an improvement in oxygenation; dopamine was given to three infants who were oliguric. All infants survived, and only one infant developed chronic lung disease which was defined by the infant's need for supplemental oxygen beyond 30 days of life.

Complete cartilage-ring tracheal stenosis associated with anomalous left pulmonary artery: the ring-sling complex

The persistent high mortality in infants with pulmonary artery "sling" (retrotracheal anomalous left pulmonary artery) is primarily due to the coexistence in such patients of long-segment tracheal stenosis due to complete cartilage rings. Five such patients are reported. Airway studies (by filtered high-kV radiography, bronchography, and/or CT) showed low carina, horizontal equal-length right and left mainstem bronchi, and long-segment tracheal stenosis. The length of the stenosis far exceeded the contact with the pulmonary sling. The suggested term "ring-sling complex" for such patients correctly places emphasis on detection of the tracheal malformation, which currently has no satisfactory surgical treatment.

Localized pneumothorax adjacent to a collapsed lobe: a sign of bronchial obstruction

In the presence of lobar collapse due to bronchial obstruction with increased recoil of the affected lobe, an unusual localized pleural collection of air may result. Three patients are reported in whom obstruction of the right upper lobe bronchus resulted in radiographic findings of a dense contracted right upper lobe with an adjacent apical intrapleural gas collection. The gas resolved after bronchoscopic removal of foreign bodies in two patients and after removal of an endotracheal tube from the intermediate bronchus in the third patient.

Mortality and morbidity in infants less than 1,001 grams birth weight

A prospective study of 54 infants with birth weights of 1,000 gm or less was conducted over a period of two years. Of the 26 infants who survived, 24 weighed between 750 and 1,000 gm; two infants died after discharge and one was lost to follow-up, leaving 23 in whom serial observations were made over 18 months to 3 years of age. The incidence of neurologic deficit in these infants was 17% and of intellectual deficit, 13%. Of the four who were abnormal neurologically, two had spastic quadriparesis, one static encephalopathy, and one hydrocephalus secondary to intraventricular hemorrhage. The three with intellectual deficit had a developmental quotient less than 85. Of the perinatal factors examined, only birth asphyxia correlated significantly with both neonatal mortality and subsequent morbidity. Six (26%) of the surviving infants had mild, nonblinding retrolental fibroplasia; only one of them had a significant refractive error that required corrective lenses for vision. Sepsis was a significant contributor to neonatal mortality in ten of 28 infants who died, but was detected in only one survivor. Although the prognosis for the infant weighing 1,000 gm or less at delivery has improved significantly, there is promise for still further improvement by reducing perinatal asphyxia.

A spring-loaded needle for emergency evacuation of pneumothorax

A tension pneumothorax requires immediate relief. Emergency evacuation of pneumothorax using a spring-loaded needle to prevent lung perforation is described. A case example is also presented. Over 3 years, this technique proved to be safe and easy to perform.