Mortality from neonatal diaphragmatic hernia

An analysis of tolazoline therapy in the critically-ill neonate

There were 47 seriously-ill neonates with medical causes of respiratory distress and 10 infants with severe respiratory distress secondary to a congenital diaphragmatic hernia treated with tolazoline according to a strict protocol designed to manage persistent fetal circulation (PFC). Of the 47 infants, 28 (60%) had a positive response defined as an increase in the pO2 greater than or equal to 24 mm Hg within 4 hr of beginning the drug. Of 7 infants, 4 with congenital diaphragmatic hernia had a positive response. The mean increase in the pO2 for the 47 infants was statistically significant (p less than .05). Of the 47 infants with medical disorders, 27 survived (survival 57%), whereas only 2 of the 10 infants with congenital diaphragmatic hernia and severe persistent fetal circulation survived (survival 28%). Erythema (60%), hematest positive gastric aspirates (55%), thrombocytopenia (45%), hyponatremia (40%) and increased gastric aspirates (36%) were the most common adverse effects occurring during tolazoline infusion. Hypotension occurred in nine cases, but was transient. Of the 27 survivors, 20 with medical causes of persistent fetal circulation were evaluated at age 1 yr. Eighty percent of these infants studied were considered normal as defined by an MDI and PI of the Bayley Scales of greater than or equal to 70. These data suggest that tolazoline is a useful adjunct in the management of neonates with PFC. In addition, tolazoline was more effective in mechanically ventilated neonates treated with respiratory paralytic agents. Although tolazoline resulted in a significant improvement in the paO2 in 4 infants with congenital diaphragmatic hernia, it did not appear to improve mortality in these infants.

The pharmacologic treatment of newborn diaphragmatic hernia--a 2-year evaluation

From 1968 to 1976 inclusive, 69 neonates with diaphragmatic hernias had corrective surgery within 18 hr of birth and the survival rate was 41%. During the same time, all babies with similar hernias who were operated on later than 18 hr from the time of birth survived. Our present interest has been focused on the pulmonary artery and its hypertension with the subsequent development of right to left shunting through the patent ductus arteriosus. During 1977 and 1978, we attempted to enter 19 consecutive newborns 18 hr of age or less with symptomatic Bochdalek diaphragmatic hernias into a "Collins protocol" for treatment. This included four stages: newborn nursery initial resuscitation, operation, cardiac catheterization, and ICU monitoring and pharmacological therapy. There was a total of seven survivors (36%), however for a number of reasons only eight babies really had a complete entry into this protocol and of these eight, five survived. Although this study is far from complete, some initial information and concepts are forthcoming. It is now apparent to us that there are three distinct groups into which these very early newborns fall: minimal pulmonary hypoplasia, unilateral hypoplasia and bilateral hypoplasia. The first group probably does not need pharmacologic support, while in the last it probably does not help. Further interest in other more specific pulmonary pharmacologic agents is now being considered as well as some way of early recognition of which baby is going to fit into which group, so that only the ones that need this treatment will get it.

Agenesis of the left diaphragm: surgical repair and physiologic consequences

Agenesis of the hemidiaphragm is an unusual congenital anomaly associated with a high mortality. This paper presents the fourth patient to survive the neonatal period with agenesis of the hemidiaphragm. He was an identical twin, weighing 1.5 kg and his clinical course was characterized by ipsilateral pulmonary hypoplasia, large alveolar-arterial gradient for oxygen, persistent fetal circulatory pattern and ventilator dependence. These abnormalities suggest a pathophysiology similar to that observed in patients with Bochdalek hernia. The surgical correction, postoperative care and observation of pulmonary function following repair of agenesis of the left diaphragm are described.

Pediatric diaphragmatic hernias. An 11 year experience

A retrospective study of 36 infants and children with diaphragmatic hernia was carried out. Mortality was confined to the group of patients identified between birth and 6 hours of life. Survivors appeared to be separable early in life from those who died on the basis of clinical status at birth measured by the Apgar, by ventilatory capacity of the lung reflected by carbon dioxide pressure and by acid base balance. Oxygenation, time from birth surgery, maternal factors, and labor and delivery appeared to play no role in survival. Hypoplasia of the lung reflected in low lung weights in those who died did not correlate with initial clinical status or blood gas data. Surgical adjuncts to reduction and closure of the hernia did not appear to have an effect on survival. Definition of patients at high risk of dying will permit critical application an evaluation of modes of treatment beyond those now used regularly in the care of these desperately ill infants.

The effect of overdistention of the lung on pulmonary function in beagle puppies

The removal of one lung from a beagle puppy results in minimal interference with lung function or the arterial gases. The removal of air from the empty pleural cavity results in a shift of the mediastinum and overdistention of the contralateral lung. An immediate decrease in the PO2 and increase in the PCO2 is seen. Significant increase in the alveolar-arterial CO2 gradient reflected marked increase in dead space ventilation. Biopsies of the overdistended lung demonstrated emphysema and disruption of alveoli. These changes may explain some of the deterioration of lung function and the complication of contralateral pneumothorax following repair of a Bochdalek diaphragmatic hernia. Our study suggests that the mediastinum should be stabilized in the midline after repair of a diaphragmatic hernia or after a pneumonectomy in an infant or small child.

The effects of intrapleural pressure on respiratory insufficiency

Newborns with congenital diaphragmatic hernia generally survive operative repair of the hernia but develop progressive respiratory insufficiency that proves fatal. One cause for the progressive respiratory insufficiency may be the overexpansion of the contralateral lung. It is postulated that the overexpansion occurs due to the empty space created by the lack of expansion of the hypoplastic lung on the side of the hernia. To test this theory, an animal experiment was devised to mimic the postoperative state in patients with diaphragmatic hernia. It was concluded that (1) A decrease in intrapleural pressure below normal in an empty hemithorax causes the opposite lung to overexpand into the empty hemithorax in neonatal Beagle puppies. (2) The overexpansion resulted in progressive respiratory insufficiency. (3) Increasing the intrapleural pressure by insufflation of air into the empty hemithorax stopped the overexpansion of the contralateral lung. (4) By not allowing the contralateral lung to overexpand, progressive respiratory insufficiency was prevented. (5) This may be a useful technique in neonates with congenital diaphragmatic hernia.

Primary pulmonary hypoplasia in the neonate

Infants with primary pulmonary hypoplasia with respiratory distress immediately after birth, but usually elude early diagnosis. They have no other abnormalities, but frequently develop signs and symptoms of the PFC syndrome. Roentgenographically, they show small, clear lungs and are prone to develop complicating pneumothoraces. The clinical, roentgenographic, and pathologic features of eight infants with primary pulmonary hypoplasia are presented.

Congenital diaphragmatic hernia

A description of the pathology, clinical presentation and management of congenital diaphragmatic hernia is given together with the results obtained in Newcastle during the last seven years. Some suggestions are made for improved management.

Hemodynamics of congenital diaphragmatic hernia in lambs

Despite surgical treatment, congenital foramen of Bochdalek diaphragmatic hernia continues to carry a high mortality rate due to associated respiratory insufficiency. We studied the pathologic and hemodynamic changes that result from this condition in lambs. Surgical creation of diaphragmatic hernias in fetal lambs was performed in utero with subsequent delivery by cesarean section near term. Cardiac catheterization was performed on these newborn lambs immediately after delivery, before and after surgical repair of the defect. Data from five of these lambs were compared to data obtained from seven normal lambs. Pulmonary hypertension was found only in lambs with hernias. Pulmonary artery pressures and the mean ratio of pulmonary to systemic resistance were higher in experimental lambs. Oxygen saturation and average cardiac index were higher in normals. Lambs in the experimental group, but not in the control group, had large left-to-right shunts at the level of the ductus arteriosus in the early neonatal period. Arterial oxygen saturations were consistently low with no differences in pre- and post-ductal samples, which suggests right-to-left shunting at the atrial level or physiologic shunting across the unexpanded lungs. No further expansion of the hypoplastic lungs occurred following decompression by surgical hernia repair, but transient hemodynamic improvement was noted in some cases. Surgical ligation of the ductus arteriosus did not significantly alter the clinical condition of the lambs. Lungs in lambs with hernias were grossly abnormal, the left appearing more hypoplastic than the right.

Congenital diaphragmatic hernia: the hidden mortality

From 1969 to 1975, 33 cases of congenital diaphragmatic hernia (CDH) were treated at the National Hospital of Norway with a "visible" or operative mortality of 30%. At least 37 additional infants with CDH who died soon after birth and did not come to the attention of a major referral center were identified retrospectively from a comprehensive survey of neonatal deaths. CDH occurred at least once in every 5455 live births and the "true" mortality was 66%. More than half of the infants born with CDH during this 6-yr period died before they could be treated, contributing to a substantial "hidden" mortality.

Management of pulmonary insufficiency in diaphragmatic hernia using extracorporeal circulation with a membrane oxygenator (ECMO)

Persistent fetal circulation (PFC) causes severe pulmonary insufficiency in patients who have demonstrated adequate lung function following diaphragmatic hernia repair. Patent ductus arteriosus (PDA) ligation corrects this condition, but carries the risk of sudden right ventricular failure. Pharmacologic reversal of PFC may be attempted, and if unsuccessful, prolonged venoarterial bypass becomes necessary to provide effective pulmonary support. PDA ligation can then be performed safely and maturation of the pulmonary vasculature allowed to occur. Pulmonary artery pressure monitoring is essential.

"Acquired" congenital diaphragmatic hernia

"Acquired" congenital diaphragmatic hernia (ACDH), has been defined as delayed or late appearance of a congenital diaphragmatic hernia after a documented time periol of postnatal life with no evidence of herniation. Three new cases are presented. This diagnosis has been characterized on the basis of a review of these cases and 14 additional patients from the literature. A classification based upon timing of herniation and state of pulmonary development is presented.

A new approach to congenital posterolateral diaphragmatic hernia

The theory is advanced that increased pulmonary vascular resistance, resulting in a state of fetal circulation, with right-to-left shunting through the ductus arteriosus, is the main reason that many patients do not survive after repair of a diaphragmatic hernia. Three patients are presented (who, by Raphaely's criteria, were destined for a fatal outcome) in whom the ductus was ligated, and vasodilator drugs were infused into the pulmonary artery. All three demonstrated definite improvement in oxygenation. Two expired after 6 days, one of whom was found at autopsy to have intestinal volvulus and gangrene, and the other multiple plumonary emboli. One case, so managed, survived. The suggestion is made that pulmonary hypoplasia is not the main reason for the high mortality rate after diaphragmatic hernia repair, and that additional laboratory and clinical investigation of the pulmonary circulation may lead to significant improvement in results.

Congenital anomalies of the diaphragm. Personal experience with thirty-five consecutive cases

A personal experience of thirty-five consecutive patients with congenital anomalies of the diaphragm is reported. The anomalies included twenty-five Bochdalek hernias, seven diaphragmatic eventrations, and three esophageal hiatal hernias. Except for the patients with esophageal hiatal hernias, virtually all patients presented with respiratory embarrassment, twenty-seven of the thirty-five within 24 hours of birth. An especially high mortality is associated with this early onset of symptoms. The treatment was surgical with a thoracic approach used for right Bochdalek defects and eventrations, and an abdominal approach used for left Bochdalek hernias. The importance of proper preoperative and postoperative management in a well equipped neonatal intensive care unit is emphasized.

Congenital posterolateral diaphragmatic hernia

The infant who is born with a posterolateral diaphragmatic hernia who becomes symptomatic at or soon after birth requires urgent care. Surgical reduction of the diaphragmatic hernia must be accomplished quickly. Respiratory and metabolic acidosis must be treated appropriately. The parents should be informed of the gravity of their infant's problem and reassurred by appropriate explanation of the nature of the defect and the therapeutic requirements. If the infant dies, the parents are in need of empathy, reassurance, and adequate explanation so that they do not have lingering doubts regarding the etiology of the anomaly and the adequacy of the therapy. If the infant lives, the medical team can share the feeling of a job well done.