Usefulness of surveillance cultures in neonatal extracorporeal membrane oxygenation.

Sepsis is difficult to identify in patients treated with extracorporeal membrane oxygenation (ECMO). This study evaluates the usefulness of surveillance cultures obtained during ECMO. We retrospectively reviewed the records of 187 patients from four ECMO centers with birth weights 1,574 to 4,900 gm and gestational ages 33-43 weeks, over a 4 year interval. Most patients had surveillance blood cultures daily, and tracheal aspirates and urine culture every other day. Charts were reviewed for culture results before, during, and for the 7 days after ECMO, and clinical response to the culture results. A total of 2,423 cultures were obtained during 1,487 days of ECMO, of which 155 were positive (6.4%): 13 of 1,370 blood cultures (0.9%), 137 of 850 tracheal aspirate cultures (16%), and 5 of 203 urine cultures (2.3%). After 72 hours, tracheal aspirate cultures became positive with nosocomial organisms in 33 of 131 patients. None of 153 bacterial urine cultures were positive, and only one of 34 viral urine cultures were positive (CMV). We conclude that routine daily blood cultures are not useful in neonatal ECMO. Tracheal aspirate cultures may be helpful in the management of antibiotic therapy in patients on ECMO for more than 5 days. Routine bacterial urine cultures did not provide useful information.

A multicenter trial of 6-aminocaproic acid (Amicar) in the prevention of bleeding in infants on ECMO.

BACKGROUND/PURPOSE: Intracranial hemorrhage (ICH), is a major source of morbidity and the leading cause of death in neonates treated with extracorporeal membrane oxygenation (ECMO). Anecdotal reports have suggested that epsilon-aminocaproic acid (EACA) can decrease the risk of ICH. The purpose of this study was to evaluate, in a multiinstitutional, prospective, randomized, blinded fashion, the effect of EACA on the incidence of hemorrhagic complications in neonates receiving ECMO. METHODS: All neonates (except congenital diaphragmatic hernia) who met criteria for ECMO at three institutions were eligible for enrollment. EACA (100 mg/kg) or placebo was given at the time of cannulation followed by 25 mg/kg/h for 72 hours. Bleeding complications, transfusion requirements, and thrombotic complications were recorded. Post-ECMO imaging included head ultrasound scan computed tomography (CT) scan, and duplex ultrasound scan of the inferior vena cava and renal vessels. RESULTS: Twenty-nine neonates were enrolled (EACA, 13 and placebo, 16). Five (17.2%) patients had a significant (grade 3 or larger) ICH. There was no statistical difference in the incidence of significant ICH in patients who received EACA (23%) versus placebo (12.5%). Septic patients accounted for all of the ICH in the EACA group. Thrombotic complications (aortic thrombus and SVC syndrome) developed in two patients from the placebo group. There was no difference in thrombotic circuit complications between groups. CONCLUSIONS: Our results suggest that the use of EACA in neonates receiving ECMO is safe but may not decrease the overall incidence of hemorrhagic complications.

Utility of daily head ultrasonography for infants on extracorporeal membrane oxygenation.

BACKGROUND/PURPOSE: Intracranial hemorrhage (ICH) is a major concern during extracorporeal membrane oxygenation (ECMO). Daily cranial ultrasonography has been used by many ECMO centers as a diagnostic tool for both detecting and following ICH while infants are on bypass. The purpose of this patient review was to look at the usefulness of performing daily cranial ultrasonography (HUS) in infants on ECMO in detecting intraventricular hemorrhage of a magnitude sufficient to alter patient treatment. METHODS: The authors reviewed retrospectively all of the records of all neonates treated with ECMO at the Hermann Children's Hospital, Wilford Hall USAF Medical Center, Cincinnati Children's Hospital, The University of Texas Medical Branch at Galveston, and Texas Children's Hospital between February 1986 to March 1995. Two hundred ninety-eight patients were placed on ECMO during this period. All patients had HUS before, and daily while on ECMO, and all were reviewed by the staff radiologists. A total of 2,518 HUS examinations were performed. RESULTS: Fifty-two of 298 patients (17.5%) had an intraventricular hemorrhage seen on ultrasound scan. Nine of 52 patients (17.3%) had an ICH seen on the initial HUS examination before ECMO, all of which were grade I, and 43 of 52 patients (82.7%) had ICH while on ECMO. Of these ICH, 15 were grade I, 10 were grade II, 10 were grade III, and eight were grade IV. Forty of these ICH (93%) were diagnosed by HUS during the first 5 days of the ECMO course. Seven hundred eighty-six HUS were performed after day 5, at an estimated cost of $300,000 to $450,000 (charges), demonstrating three new intraventricular hemorrhages, one grade I, and one grade IV on day 7 and one grade I on day 8. Eight patients were taken off ECMO because of ICH diagnosed within the first 5 days. One patient was taken off ECMO because of ICH diagnosed after 5 days. This patient had clinical symptoms suggestive of ICH. CONCLUSIONS: Almost all ICH occur during the first 5 days of an ECMO course. Unless there is a clinical suspicion, it is not cost effective to perform HUS after the fifth day on ECMO, because subsequent HUS examinations are unlikely to yield information significant enough to alter management.

Pediatric wound infections: a prospective multicenter study.

OBJECTIVE: Surgical wound infections remain a significant source of postoperative morbidity. This study was undertaken to determine prospectively the incidence of postoperative wound infections in children in a multi-institutional fashion and to identify the risk factors associated with the development of a wound infection in this population. SUMMARY BACKGROUND DATA: Despite a large body of literature in adults, there have been only two reports from North America concerning postoperative wound infections in children. METHODS: All infants and children undergoing operation on the pediatric surgical services of three institutions during a 17-month period were prospectively followed for 30 days after surgery for the development of a wound infection. RESULTS: A total of 846 of 1021 patients were followed for 30 days. The overall incidence of wound infection was 4.4%. Factors found to be significantly associated with a postoperative wound infection were the amount of contamination at operation (p = 0.006) and the duration of the operation (p = 0.03). Comparing children who developed a wound infection with those who did not, there were no significant differences in age, sex, American Society of Anesthesiologists (ASA) preoperative assessment score, length of preoperative hospitalization, location of operation (intensive care unit vs. operating room), presence of a coexisting disease or remote infection, or the use of perioperative antibiotics. CONCLUSIONS: Our results suggest that wound infections in children are related more to the factors at operation than to the overall physiologic status. Procedures can be performed in the intensive care unit without any increase in the incidence of wound infection.

Outcome of infants requiring cardiopulmonary resuscitation before extracorporeal membrane oxygenation.

BACKGROUND/PURPOSE: Cardiopulmonary resuscitation (CPR) is reported to be used in a significant number of neonates before initiation of extracorporeal membrane oxygenation (ECMO). This report establishes the incidence of infants who require CPR before initiation of ECMO and elucidates survival rates and long-term neurological outcomes. In addition, the authors sought prognostic factors that could reliably predict survival or long-term neurological outcome before initiating ECMO support. METHODS: The Extracorporeal Life Support Organization (ELSO) registry provided data on 839 neonates who received CPR before ECMO from January 1989 to April 1995. Supplemental questionnaires on 414 infants were returned from 64 ECMO centers regarding details of the CPR event and subsequent neurological development. One-year neurological evaluations were provided on 112 infants. Data were analyzed for statistical significance using chi2, multiple logistic regression, and Kruskal Wallis one-way analysis of variance as applicable, with significance set at P < .05. RESULTS: The incidence of infants requiring pre-ECMO CPR was 13.1%. Infants who received pre-ECMO CPR had a survival rate of 60.8% versus 81.6% survival for infants who did not require CPR (P < .00001). Analysis of ELSO registry data showed survival was significantly associated with primary diagnosis, location of CPR, last pH level before ECMO, and the presence of intraventricular hemorrhage. Questionnaire data on 12-month neurological assessment showed 63% had no impairment and 4% were graded as severely impaired. Twelve-month neurological outcome was significantly associated only with primary diagnosis. CONCLUSION: A survival rate of 60.8% with good neurological outcome at 12 months in 63.4% of infants suggests that CPR alone should not be a contraindication to placing a neonate on ECMO.

Heparin-associated thrombocytopenia and thrombosis as the cause of a fatal thrombus on extracorporeal membrane oxygenation.

A rare state of acquired hypercoagulability known as heparin-associated or heparin-induced thrombocytopenia and thrombosis (HATT, HITT) exists. It appears to be caused by an antibody reaction with heparin-platelet factor 4 complexes. A mild and severe form exist, but both varieties occur after exposure to heparin. The authors describe a fatal neonatal case of hypercoagulability on extracorporeal membrane oxygenation, and their evaluation that determined the etiology as type II HATT. They discuss the pathophysiology of HATT as well as possible alternative anticoagulation approaches.

Successful separation of ischiopagus tripus conjoined twins with comparative analysis of methods for abdominal wall closure and use of the tripus limb.

The authors report the successful delivery, preoperative management, and postoperative courses of ischiopagus tripus twin girls successfully separated at 5 months of age. Surgical objectives were predicated on survival and optimum postseparation reconstructive potential for both girls. Each twin has subsequently undergone additional procedures, and both are doing well 2 years after separation. The authors reviewed 17 known cases of ischiopagus tripus separation, comparing anatomic findings, use of the tripus limb, operative strategies, and attainment of abdominal closure. This 18th case includes the first report of splitting the tripus limb and giving each girl a femur. The authors found that detailed systemic investigation, advanced coordinated teamwork with appropriate technical support, applications of new technologies or reapplication of existing technologies, meticulous planning, and favorable anatomy were vital in yielding favorable outcomes.

Complications after surgical intervention for necrotizing enterocolitis: a multicenter review.

Necrotizing enterocolitis (NEC) is a serious condition affecting predominantly the premature infant. The purpose of this study is to report a multicenter experience of complications in 252 infants requiring surgical therapy for NEC. Data from eight institutions for the years 1980 through 1990 were collected and analyzed for infants undergoing surgical therapy for NEC. Records were reviewed for gestational age, birth weight, age at operation, indications for operation, degree of intestinal involvement, operation(s) performed, complications, and 30-day mortality rates. A total of 264 infants underwent surgical intervention for NEC during the study period. Complete information was available for 252 patients. The mean gestational age was 31 +/- 5 weeks and the mean birth weight was 1,552 +/- 823 g. The mean age at operation was 18 +/- 35 days. Pneumoperitoneum was the most common indication for operation (42%). The 30-day survival rate was 72%. Eighty-one percent of patients underwent primary laparotomy, whereas peritoneal drainage was performed in 48 (19%) patients. Postoperative complications were identified in 119 (47%) patients. The most common postoperative complications were sepsis (9%), intestinal strictures (9%), and short gut (9%). Wound infections occurred in 6%, and the incidence of intraabdominal abscess formation was only 2.3%. Gestational age < 27 weeks (P < .005) and birth weight < 1,000 g (P < .005) were associated with significantly increased mortality but no increase in postoperative morbidity. The incidence of complications was similar in the very low birth weight (< 1,000 g) infants (51%) compared with infants > or = 1,000 g (46%).(ABSTRACT TRUNCATED AT 250 WORDS)

Hemorrhagic complications and repair of congenital diaphragmatic hernias: does timing of the repair make a difference? Data from the Extracorporeal Life Support Organization.

The authors reviewed the Extracorporeal Life Support Organization (ELSO) data base of all neonates placed on extracorporeal membrane oxygenation for whom CDH was diagnosed between January 1989 and December 1991. For 483 neonates, there were complete data concerning timing of the hernia repair in relation to ECMO. The overall incidence of hemorrhage was 43% (57% among nonsurvivors, 32% among survivors; P < .05). The most common bleeding sites were surgical repair site (24%), head (11.5%), cannulation site (7.5%), and gastrointestinal (5%). Fatal hemorrhage occurred in 4.8% (23 of 483). The most common sites of fatal hemorrhage were head (48%), pulmonary (17%), and abdominal (17%). Bleeding complications were significantly greater for patients repaired on ECMO (58%) versus those repaired before (37%) or after (21%) (P < .05). Surgical-site hemorrhage requiring transfusion occurred in 38% of those repaired on ECMO versus 18% and 6% of those repaired before and after, respectively (P < .05). Gastrointestinal and "other" sites of hemorrhage were significantly more common in those repaired on bypass. The number of patients repaired on ECMO increased from 22% to 48% over the 3 years (P < .05). The incidence of hemorrhagic complications did not differ significantly among the 3 years (P > .05). Repair of the hernia defect while on bypass was associated with significantly greater bleeding complications. These data should be useful in the planning of future prospective trials.

Predicting ventilation failure in children with inhalation injury.

Despite advances in mechanical ventilatory support for patients with smoke inhalation injury, including the use of high-frequency flow-interruption ventilators such as the VDR, inhalation injury alone may increase mortality by as much as 20% in patients with thermal injury, and up to 60% when pneumonia occurs. Inhalation injury causes a primary large and small airway epithelial insult that results in ventilation abnormalities, rather than a primary alveolar lesion that results in oxygenation abnormalities as occur in multiple-system organ failure. Patients with inhalation injury requiring high ventilatory pressures experience complications of barotrauma and frequently succumb to necrotizing tracheobronchitis and oxygenation abnormalities after 2 to 4 weeks of mechanical ventilation. Ventilatory indexes obtained early in the postburn period allow the development of accurate predictive formulae that identify patients who will not be adequately supported by mechanical ventilation after smoke inhalation injury. Early identification of such patients will allow rapid conversion to other methods of ventilatory support that effect gas exchange, with minimal risk of further barotrauma, while inhalation injury healing occurs. Such predictors may be developed for other disease processes that are characterized by severe pulmonary ventilatory dysfunction.

Endobronchial hamartoma treated by bronchoscopic excision.

Endobronchial hamartoma is a rare lesion, with only 65 cases previously reported in the English literature. An additional case is reported here. The patient was successfully treated by bronchoscopic excision of the hamartoma.

Prosthetic diaphragm reconstruction in the growing animal.

Widespread use of extracorporeal membrane oxygenation (ECMO) has allowed an increasing number of infants with total agenesis of the diaphragm to survive. Polytetrafluoroethylene (PTFE) is the most widely used material for reconstruction. However, recurrent hernia is a growing problem; PTFE also does not grow with the patient. This study evaluated different materials for diaphragmatic reconstruction in growing animals. Sprague-Dawley rats with a mean weight of 93 g were anesthetized and underwent laparotomy. The control group had an incision into the diaphragm with primary repair. The other three groups underwent complete removal of the left hemidiaphragm and were randomly assigned to one of three reconstruction methods: oxidized cellulose, polyglactin mesh, or a 1-mm PTFE patch. All patch materials were sewn around the ribs circumferentially and into the membranous portion of the central diaphragm medially with 4-0 silk. Thirty-seven animals survived operation, were followed with weekly chest radiographs, and were killed when they reached 400 g. The radiographs were reviewed in a blinded fashion by two observers as were the necropsies, and rib deformity was graded on a scale of 0 to 3. Histological examination of several animals from each group was performed. There was significantly greater rib deformity (2.0 v 0.2, P < .01) in the PTFE group versus controls with 5 of 10 animals also having a smaller thorax. The PTFE pulled away from the chest wall in the animals leaving a fibrous remnant anteriorly. The polyglactin group had significantly more animals with eventration (P < .03, 7/10) compared with all others.(ABSTRACT TRUNCATED AT 250 WORDS)

The atonic baggy rectum: a cause of intractable obstipation after imperforate anus repair.

Three children with successful imperforate anus repairs had chronic, intractable obstipation and recurrent fecal impaction refractory to diligent medical therapy. All had massive stool-filled rectums up to 14 cm in diameter on abdominal radiographs. They responded well to resection of the baggy atonic rectum with low anterior anastomosis. The massively dilated atonic rectal pouch in some children with repaired imperforate anus can demonstrate abnormal motility characterized by poor peristalsis and propulsion. This results in recurrent obstipation, impaction, and soiling refractory to the usually successful medical management.

Persistence of Barrett's esophagus in children after antireflux surgery: influence on follow-up care.

Adenocarcinoma arising in Barrett's esophagus has recently been described in two children aged 11 and 14 years. The long-term follow-up of Barrett's esophagus in children is not well described. We evaluated 16 cases of Barrett's esophagus in children treated at this institution during the last 16 years. Ages ranged from 1.2 to 16 years (mean, 10.3 years). There were 11 boys and 5 girls. Barrett's esophagus was documented by endoscopy in 14 instances and at autopsy in 2 patients with secretory diarrhea and tetralogy of Fallot who died of sepsis. Two children had cancer (neuroblastoma, leukemia) and died of their malignant disease. Five patients had cerebral palsy, 1 esophageal atresia, 1 Fanconi's anemia, and 5 were otherwise normal children. Six were treated medically. Eight patients underwent Nissen fundoplication for complications of gastroesophageal reflux (GER). Five patients were available for follow-up endoscopy (mean, 2 years; range, 1.1 to 5.4 years). Endoscopy was performed on a yearly basis, obtaining biopsy specimens from multiple levels of the esophagus. Four children had satisfactory clinical response to an antireflux procedure including the resolution of a stricture in one case. However, in all 5 cases persistent metaplastic epithelium was documented and showed no evidence of regression. Although there has been speculation that Barrett's esophagus in children may be more likely to revert to normal squamous epithelium than in the adult, there has been only one case of regression in 180 cases of Barrett's esophagus occurring in children described in 37 reports in the literature.(ABSTRACT TRUNCATED AT 250 WORDS)

Digital artery embolization as a result of fibromuscular dysplasia of the brachial artery.

A 74-year-old woman was admitted to the hospital with sudden onset of a blue, painful right index finger, and the condition progressed to digital ulceration. The ulcer gradually healed over a period of 2 months. Peripheral pulses, Doppler-derived brachial and radial systolic pressures, and results of an echocardiogram were normal. Digital pulse volume recordings showed obstructive waveforms in all digits of the right hand. Arteriography showed a normal arch and normal innominate, subclavian, and axillary arteries. The midbrachial artery was markedly abnormal and had alternating areas of stenosis and aneurysm formation. Multiple occlusions involved the palmar arch and proper digital arteries. The abnormal brachial artery segment was excised and replaced with an autogenous reversed saphenous-vein conduit. Histologic examination confirmed the lesion to be medial fibromuscular dysplasia. Fibromuscular dysplasia that involves upper extremity arteries is extremely uncommon and rarely presents with digital artery embolization. This case emphasizes the importance of exclusion of proximal reconstructible arterial occlusive disease by means of complete arteriographic examination of patients who were admitted with unilateral finger or hand ischemia.

Open lung biopsy in the critically ill newborn.

Experience with 17 open lung biopsies in critically ill premature neonates was reviewed. Despite their small size, prematurity, and near maximal ventilator requirements, the infants suffered no significant complications. In three cases, an infectious agent was identified. In one case end-stage lung fibrosis associated with persistent (greater than 3 months), severe respiratory failure prompted termination of support. In the remainder of the cases, definitively ruling out infection allowed the confident trial of a course of steroids in an attempt to treat bronchopulmonary dysplasia. Unlike older patients, the definitive diagnosis of no infection in the premature neonate is just as informative as the diagnosis of an infection. Used judiciously, open lung biopsy can be performed in the premature infant with acceptable morbidity and mortality.

Breath hydrogen excretion in the premature neonate.

We measured breath hydrogen excretion in 103 neonates from birth to as late as 2 months of age. The patients weighed less than 2000 g at birth and were part of a study of hydrogen excretion as a screening test for necrotizing enterocolitis. Hydrogen excretion in parts per million was normalized for the quality of the expired air by dividing by the Pco2 of the gas sample The rise in the H2/CO2 ratio was influenced by gestational age, energy intake, and antibiotic usage but not by the daily frequency of feeding. The mean +/- SD peak H2/CO2 ratio was 5.1 +/- 3.6 ppm per millimeter of mercury and occurred at 16.0 +/- 11.0 days of age. The age at which the peak H2/CO2 occurred varied with gestational age. Patients born between 23 and 28 weeks gestational age (n = 34) were 22.9 +/- 13.1 days of age when they experienced their peak H2/CO2 ratio, whereas those born between 29 and 34 weeks gestational age (n = 62) were 12.2 +/- 7.5 days of age. The age at which the peak H2/CO2 ratio occurred did not differ between these two groups when corrected for the age at which oral intake exceeded 420 kJ/kg per day. These results suggest that premature neonates require experience with ingesting more than 420 kJ/kg per day before bacteria and carbohydrates are present in large enough quantities to permit measurable hydrogen production. This information will be useful in future studies of premature gut development and physiology and in studying pathologic processes in which malabsorption may play a role.

Breath hydrogen excretion as a screening test for the early diagnosis of necrotizing enterocolitis.

We measured breath H2 excretion in 122 neonates from birth to 1 month of age. The patients weighed less than 2000 g at birth and thus were at risk for developing necrotizing enterocolitis (NEC). Hydrogen excretion was normalized for the quality of the expired air by dividing by the carbon dioxide pressure of the gas sample. The mean (+/- SD) peak H2/CO2 ratio was significantly different between the seven patients who subsequently developed NEC (9.4 +/- 2.7 ppm/mm Hg) and the 115 patients who did not (5.0 +/- 3.5 ppm/mm Hg). The prevalence of NEC was 5.7% in the present study. Defining a positive test as one with a ratio value of greater than or equal to 8.0 ppm/mm Hg, the resulting screening test had a sensitivity of 86% and a specificity of 90%. The screening test yielded a 33% predictive value of a positive test and a 99% predictive value of a negative test. High H2 excretion occurred eight to 28 hours before the earliest clinical signs of NEC. Breath H2 excretion is a simple noninvasive test that may be useful in the management of the premature neonate at risk for the development of NEC.

Peritoneal drainage for necrotizing enterocolitis.

This study evaluates the role of primary peritoneal drainage (PPD) in the management of neonatal necrotizing enterocolitis (NEC). Of 169 patients with definite NEC, 92 (55%) underwent operation: primary laparotomy, 41 patients (45%); and PPD, 51 patients (55%). Seventeen (33%) of the PPD infants had subsequent laparotomy within seven days. Pneumoperitoneum was the indication for operation in 37% of the primary laparotomy and 67% of the PPD infants. Following PPD, 34 patients (67%) showed clinical improvement. Operative survivals were as follows: primary laparotomy, 83%; PPD, 53%. Infants who had PPD had a significantly lower mean birth weight, gestational age, preoperative pH and platelet count, and a significantly higher incidence of intraventricular hemorrhage and patent ductus arteriosus. For infants weighing less than 1,000 g at birth, the survival was similar following primary laparotomy (57%) and PPD (52%); this occurred in spite of the higher incidence of adverse risk factors in the PPD infants. For infants weighing greater than 1,000 g, the survival was 86% following primary laparotomy and 62% after PPD; in this group, all the early deaths following PPD occurred in critically ill infants who died within 48 hours of drainage. The late survival rates were as follows: primary laparotomy, 76%; PPD, 35%. More than half of the late deaths following PPD were not related to NEC, reflecting the difference between the two patient populations. Primary peritoneal drainage is a useful adjunct to resuscitation of the critically ill infant with complicated NEC, particularly prematures less than 1,000 g birth weight with intestinal perforation. Primary peritoneal drainage is not an alternative to laparotomy, which is recommended when an optimal clinical response has been achieved.