Pediatric surgery. Second of two parts

Physiological impact of pneumoperitoneum on gastric mucosal CO2 pressure during laparoscopic versus open appendectomy in children

INTRODUCTION

Funded knowledge about the physiological impact of laparoscopic surgery in children is sparse. Although there are data on hemodynamic compromise after creation of a pneumoperitoneum in children, little is known about microcirculatory changes at the mucosa level. Therefore, the aim of this study was to assess gastric microcirculation by continuous gastric air tonometry in the setting of laparoscopic versus open appendectomy.

PATIENTS AND METHODS

Twenty children 5-17 years old undergoing laparoscopic and 7 children undergoing open appendectomy were included in the study. Gastric intramucosal CO(2) pressure (pCO(2)i) was measured under standardized flow and intraperitoneal pressure using continuous air tonometry (TONOCAP(®), Datex Ohmeda), and ΔpCO(2) (pCO(2)i - end-expiratory CO(2) pressure [pCO(2)e]) was obtained for the time course of surgery.

RESULTS

ΔpCO(2) increased significantly from the baseline value not only in the laparoscopic group but also in the open surgery group. Even though ΔpCO(2) was higher in the laparoscopic group at all time points, the overall increase in ΔpCO(2) for both groups was uniform. The largest differences were observed during the initial 20 minutes of the operation. The changes observed were exclusively due to an increase of pCO(2)i in relation to a constant pCO(2)e.

DISCUSSION

In the setting of a standardized, simple operation in an otherwise healthy child above the age of 5 years, our data suggest that the effect of a pneumoperitoneum on splanchnic perfusion is comparable to the compromise caused by open surgery. Further research must be obtained when evaluating the full impact of laparoscopy in children.

Conservative approach to the treatment of injured liver and spleen in children: association with reduced mortality

BACKGROUND

Previous analyses of the safety of the conservative versus the operative approach to the treatment of liver and spleen blunt injuries in children often failed to account for differences in quality of care and expertise among dedicated pediatric trauma center, non-pediatric centers, centers without trauma units, and non-trauma centers. To eliminate this potential bias, the present study examined changes in the rate of surgery and their impact on outcome within the same medical centers over time.

METHODS

The Israel Trauma Registry was searched for patients <18 years who were treated for non-penetrating liver or spleen injuries from 1998 to 2004. Patients were grouped by period, 1998-2000 and 2001-2004, and compared for type of injury, severity of injury, type of treatment, and inpatient mortality.

RESULTS

The earlier period (1998-2000) was characterized by a significantly higher rate of operations compared with the later period (2001-2004) (P = 0.001) and higher in-hospital mortality (P = 0.04). Injury severity scores, type of organs injured, and accompanying injuries were similarly distributed in the two groups.

CONCLUSIONS

Despite the similarity in the severity and characteristics of the intraabdominal injuries in 1998-2000 and in 2001-2004, the proportion of children treated conservatively increased over time, concomitant with a significant drop in inpatient mortality. We attribute this shift over a relatively short interval to increased experience and greater acceptance of conservative management in this setting.

Prenatal diagnosis of congenital malformations and parental psychological distress-a prospective longitudinal cohort study

OBJECTIVE

To test whether postnatal psychological distress in parents of babies with congenital malformations is reduced by prenatal diagnosis.

METHODS

A prospective observational longitudinal cohort study was conducted at two Norwegian hospitals. We included 293 parents of babies with congenital malformations (prenatal detection rate: 36.5%) referred for neonatal surgery and 249 parents of healthy babies (comparison group). Parental psychological responses were assessed on three postnatal occasions by psychometric instruments (GHQ-28, STAI-X1, and IES).

RESULTS

Significantly increased psychological distress (GHQ-28) was reported by parents who received prenatal diagnosis as compared to postnatal diagnosis; acutely 28.9 versus 24.4, P = 0.006 (comparison group: 19.6); at 6 weeks 26.8 versus 21.5, P < 0.001 (comparison group: 17.7); and at 6 months 22.6 versus 18.7, P = 0.015 (comparison group: 16.6). Mothers consistently reported higher levels of distress than fathers. Multiple linear regression analysis showed that prenatal diagnosis and being a mother significantly predicted severity of acute psychological distress. At 6 weeks and 6 months, mortality and associated anomalies were significant independent predictors of psychological distress.

CONCLUSION

Controlling for other covariates, we found that prenatal diagnosis of congenital malformations was a significant independent predictor of acute parental psychological distress after birth.

Cushing's syndrome due to ectopic production of corticotropin-releasing hormone in an infant with ganglioneuroblastoma

OBJECTIVE

To report the first recognized case of Cushing's syndrome due to a corticotropin-releasing hormone (CRH)-secreting ganglioneuroblastoma, which was found in an 18-month-old boy with hypertensive encephalopathy.

METHODS

The clinical, biochemical, and immunohistochemical characteristics of this rare syndrome are described, and the relevant literature is reviewed.

RESULTS

An 18-month-old boy with a history of recent weight gain was admitted because of sudden onset of right fixed esotropia and left facial palsy after episodes of emesis. Magnetic resonance imaging showed old left frontal lobe and right hypothalamic infarcts. The patient had generalized obesity, decelerated linear growth, hypertrichosis, hypertension (144/103 mm Hg), hypokalemia, and proteinuria. The 24-hour urinary excretion of free cortisol, catecholamines, and metanephrines was increased. The serum cortisol concentration after a 1-mg overnight dexamethasone suppression test (DST) was 53.7 mg/dL (normal, <5). The serum adrenocorticotropic hormone (ACTH) concentration was 7 pg/mL (normal, 10 to 60), and the CRH level was 439 pg/mL (normal, 24 to 40). An overnight high-dose DST (8 mg) failed to suppress serum cortisol; however, both cortisol and ACTH were responsive to ovine CRH stimulation. Despite discordant dynamic endocrine testing and negative somatostatin receptor scintigraphy, computed tomography showed a right 3.6- by 3.0-cm extra-adrenal retroperitoneal mass with central calcification extending 7 cm cephalocaudally. The patient underwent exploratory laparotomy, followed by chemotherapy. Findings on light microscopic and immunohistochemical examination of the retroperitoneal mass were consistent with a ganglioneuroblastoma that expressed CRH, pro-opiomelanocortin, and ACTH.

CONCLUSION

The evaluation of Cushing's syndrome is one of the most complex endocrine challenges. In this case, it was due to ectopic production of CRH by a ganglioneuroblastoma. Because most CRH-producing tumors also secrete ACTH, the ectopic production may represent a paracrine phenomenon in addition to an endocrine phenomenon. The ectopic CRH may also indirectly provoke pituitary ACTH secretion. This dual mechanism may explain the resistance of the tumor to feedback inhibition and a CRH-stimulation response indistinguishable from that observed in pituitary-dependent Cushing's syndrome.

Pediatric trauma: postinjury care in the pediatric intensive care unit

Traumatic injuries occur in > 20 million children each year and are the leading source of death in children over the age of 1 yr. Mechanisms of injury and subsequent therapies for critically injured children are diverse. This review will focus on resources and management strategies for caring for the severely injured child in the pediatric intensive care unit.

Physiologically low oxygen concentrations in fetal skin regulate hypoxia-inducible factor 1 and transforming growth factor-beta3

In the first-trimester mammalian fetus, skin wounds heal with perfect reconstitution of the dermal architecture without scar formation. Understanding environmental molecular regulation in fetal wound healing may reveal scar-limiting therapeutical strategies for the prevention of postnatal scarring wound repair. Therefore, we performed studies on fetal skin oxygenation and skin and wound expression of hypoxia-inducible factor 1alpha (HIF-1alpha) in the sheep model in vivo and performed studies on the potential relevance of HIF-1alpha during wound healing in vitro. Skin oxygen partial pressure levels were hypoxic throughout normal development. In nonscarring fetal skin at gestation day (GD)60, HIF-1alpha could be detected neither in healthy nor in wounded tissue. At GD100, in wounds with minimal scar formation, HIF-1alpha was expressed in fibroblasts and was markedly up-regulated at the wound edge. In scarring fetal wounds at GD120, HIF-1alpha was predominantly expressed in inflammatory cells. Expression of transforming growth factor beta3 (TGF-beta3), a potent antiscarring cytokine, overlapped with HIF-1a expression at GD100. HIF-1alpha-deficient mouse embryonic fibroblasts showed impaired migratory capabilities and demonstrated that TGF-beta3, but not proscarring TGF-beta1, manifests hypoxia- and HIF-1alpha-dependent regulation. In conclusion, HIF-1alpha-dependent regulation of a potent antiscarring cytokine may provide new strategies for antiscarring manipulation of wound healing.

Advances in fetal and neonatal surgery for gastrointestinal anomalies and disease

The last decade has seen considerable improvement in the understanding and treatment of neonatal surgical disorders. Translation of basic molecular biology research to clinical practice has directly improved the understanding and treatment of a number of congenital, developmental disorders, such as Hirschsprung's disease and congenital hyperinsulinism. Miniaturized instruments and improved optics have permitted increased use of videoscopic and minimally invasive techniques to even the smallest infants. Continued improvements in prenatal imaging will permit enhanced understanding of the prenatal natural history of congenital structural disorders and the development of more specific therapies. Finally, rigorous clinical research tools have begun to be applied to rare pediatric surgical disorders with the use of organized multicenter trials. It is an exciting time for all involved in the care of neonates.