Arnold S. Leonard

The overwhelming postsplenectomy sepsis problem.

Postsplenectomy vulnerability to infection is not limited to age or disease process. Postsplenectomy infection is an emergency problem that requires immediate and accurate treatment because death is potential within a few hours of onset. Although the pathogenesis of overwhelming postsplenectomy sepsis is not completely understood, experimental evidence suggests that loss of mechanical filtration is more important than immunologic deficiences resulting from splenectomy. Certainly, a combination of both may be present. While no single measure seems to completely protect against overwhelming postsplenectomy sepsis, experimental evidence suggests that by reducing or minimizing the amount of spleen removed by newer surgical techniques, and by the addition of pneumococcal vaccine and prophylactic penicillin, the incidence of overwhelming sepsis can be reduced. Further evaluation of splenic function is necessary to assess the role of autotransplantation in the prevention of postsplenectomy sepsis (Fig. 1).RésuméLa vulnérabilité à l’infection après splénectomie ne dépend ni de l’âge, ni de la maladie originelle. Toute infection survenant après splénectomie est une urgence qui peut tuer en quelques heures: elle exige donc un traitement immédiat et adéquat. La pathogénie est encore mal précisée. Des données expérimentales suggèrent que la perte du mécanisme de filtration splénique est plus importante que le déficit immunologique, ces deux facteurs pouvant cependant coexister. Il est apparemment impossible d’assurer une protection parfaite contre les infections graves après splénectomie. Mais certaines études expérimentales indiquent qu’on peut en réduire la fréquence par les nouvelles techniques chirurgicales qui évitent la splénectomie totale, par la vaccination antipneumococcique et par l’administration préventive de pénicilline. Lorsque les fonctions de la rate seront mieux connues, il sera possible de préciser le rôle prophylactique de l’autotransplantation splénique.

Complications and risks of central venous catheter placement in children

BACKGROUND Since Aubaniacs first description in 1952, the use of central venous catheters has increased dramatically; they are now considered commonplace. Placement of these catheters, however, has an associated risk of morbidity and mortality. In most cases, this risk is outweighted by the benefit gained, especially when long-term access to the central venous system is needed for multiple transfusions, chemotherapy, antibiotics, or parenteral nutrition. A large number of central venous catheters are placed in children at our institution, usually by interns and residents. METHODS To identify associated risks and complications, we reviewed the records of 1435 consecutive catheterizations in children over a 10-year period. Data collected included age, sex, site of catheterization, type of catheter, primary disease, prior catheterizations, indication for placement, failed attempts, number of attempts, catheter misplacement, level of physician training, new needle punctures, and complications. We then used logistic regression analysis to identify independent risk factors for complications. RESULTS We noted 39 (3.1%) perioperative complications, including 19 (1.5%) arterial punctures, 10 (0.8%) pneumothoraces, 6 (0.5%) hemothoraces, 2 (0.2%) cases of superior vena cava syndrome, 1 (0.1%) episode of ventricular fibrillation that required cardioversion, and 1 episode of bleeding that required a cutaneous suture. Univariate analysis revealed that catheters placed in a subclavian vein (vs all other sites combined, P < .01) were less likely to have an associated complication. In addition, multiple attempts (vs success on first attempt, P < .0001), failed attempt (vs success at initial site, P < .0001), catheter misplacement (vs proper initial position, P < .01), and prior catheterizations (vs no prior catheterization, P < .0005) were associated with complications. Logistic regression revealed multiple attempts (vs success on first attempt, odds ratio (OR) = 5.4), failed attempt (vs success at initial site, OR = 5.2), and catheter misplacement (vs proper initial position, OR = 6.9) to be independent risk factors for complications. Age, sex, type of catheter, primary disease, indication for placement, and level of physician training (intern or resident vs staff) were not associated with complications. CONCLUSIONS Central venous catheterization in children is relatively safe, with only a 3.2% complication rate and no mortality in our series.

Malignant melanotic neuroectodermal tumor of infancy. A clinical, pathologic, ultrastructural and tissue culture study

The melanotic neuroectodermal tumor of infancy is an uncommon neoplasm typically of early childhood which has a predilection for the head and neck region, particularly the maxilla. Except for one previous example in the literature, this tumor has consistently behaved in a benign fashion. This study documents the clinical course and pathologic findings of a tumor which began in the maxilla of a 4‐month‐old boy, followed by a local recurrence, metastasis to a cervical lymph node and finally, widespread dissemination and death at 18 months, 24 months and 38 months, respectively. The tumor was initially composed of nests consisting of melanin‐containing cells and small dark cells. An elevated vanillylmandelic acid level was recorded during the course of the disease. At autopsy, the tumor in lymph nodes, liver, bone and soft tissues had a monotonous pattern of small dark cells similar to a conventional neuroblastoma. Previous ultrastructural studies indicate that the melanotic neuroectodermal tumor of infancy is composed of melanocytes and neuroblast‐like cells. Our case provided the unique opportunity to examine in sequence the ultrastructural and in vitro characteristics of a recurring and eventually metastasizing melanotic neuroectodermal tumor. Although the neuroblast‐like cells were initially difficult to identify by electron microscopy, a melanin‐producing cell line and a separate nonpigmented cell line were successfully isolated from various tumor explants. Various stages of melanosome development were identified in the pigmented cells from the local recurrences and in vitro. Dibutyryl cAMP accentuated the formation of pigment and dendritic development in the melanocytes and dendrites only in the small nonpigmented cells. Electron dense granules were observed in the cultured smaller cells and also in the lymph node and soft tissue metastases. Tyrosine hydroxylase activity was demonstrated in the neuroblast‐like cells. In the final biopsy and autopsy material, only the neuroblast‐like cells remained and the tumor resembled a conventional neuroblastoma.

Overwhelming Postsplenectomy Infection

The syndrome of overwhelming postsplenectomy infection has become well identified and accepted within the past few years. Included in the surgical armamentarium should be techniques of splenic repair in cases of trauma, awareness of the syndrome of overwhelming postsplenectomy infection, and the need for penicillin prophylaxis and pneumococcal vaccination. Autosplenic transplantation (splenosis) is also discussed.

Children with mucopolysaccharidosis: Perioperative care, morbidity, mortality, and new findings

The perioperative care, morbidity, and mortality in 30 patients with mucopolysaccharidosis (MPS) are presented. They underwent a detailed preoperative assessment and were anesthetized 141 times. An intravenous induction technique was used in most patients. It was easier to see the vocal cords, during laryngoscopy, in children with Hurler syndrome (HS) when they were younger (23 v 41 months, P < or = .01) and smaller (12 v 15 kg, P < or = .05). Preoperative obstructive breathing was associated with a significantly higher incidence of postextubation obstruction (P < or = .05). A total of 28 children underwent bone marrow transplantation (BMT); this reversed upper airway obstruction and also reversed intracranial hypertension. In children with HS, the incidence of odontoid dysplasia was 94%; 38% demonstrated anterior C1-C2 subluxation. Head and neck manipulation was limited in children with cervical spine defects. None of the 30 patients experienced spinal cord morbidity. One child suffered an intraoperative stroke; another, pulmonary edema. Severe and extensive coronary obstruction was responsible for 2 intraoperative deaths. Coronary angiography underestimated coronary artery disease.

The effect of independent variations in inspiratory- expiratory ratio and end expiratory pressure during mechanical ventilation in hyaline membrane disease: The significance of mean airway pressure

The specific aspects of the respiratory cycle during mechanical ventilation that allow for optimum gas exchange are still controversial. To further clarify the relationship of inspiratory:expiratory ratio and positive end expiratory pressure to optimum ventilation and oxygenation, five premature lambs with severe hyaline membrane disease were ventilated with volume-present infant ventilators at I:E ratios of 1:4 and 1:1 and PEEP levels of 0, 5, and 10 cm H2O. For each I:E ratio/PEEP combination, pH, Pao2, PaCO2, PAO2, PACO2, peak inspiratory pressure, mean inspiratory pressure, and mean airway pressure were measured and compared. Optimum ventilation and oxygenation were related to MAP, but not to I:E ratio, PIP, or MIP. As MAP increased from 6 to 14 cm H2O, progressive improvement in Pao2, PaCO2 (A-a) DO2 and (a-A) DCO2 was evident. Above 14 cm H2O, there was progressive deterioration in these measurements. There was also a direct relationship between MAP and mean pleural pressure. These results indicate that during mechanical ventilation there is an optimum MAP at which gas exchange is best. Since MAP changes with any change in PIP, PEEP, or I:E ratio, it provides a useful composite measure of all pressures transmitted to the airways by the ventilator.

Blunt trauma in adults and children: a comparative analysis

Trauma remains the major cause of death in children and young adults. Adult and pediatric patients differ significantly in both mechanism of and physiologic response to injury. We reviewed the records of all consecutive adult and pediatric blunt trauma patients admitted to a major metropolitan trauma center for a 10-year period. An extensive computerized database has been maintained for all patients since 1977. A comparative statistical analysis of mechanism of injury, specific organ injury, and clinical outcome was performed. Altogether, 1,722 adults and 289 children were treated during the study period. Blunt trauma accounted for 82.8% of adult and 94.3% of pediatric injury (p = 0.00005), and only these patients were considered for analysis. Diagnostic peritoneal lavage was performed in 249 children and 1,464 adults, with a respective accuracy of 99.6% and 97.2%. Mechanism of injury was comparable for both groups, although children were far more likely to be injured by falls, bicycle accidents, or struck by an automobile. Comparative analysis of specific injuries demonstrated significantly fewer pediatric chest (p = 0.001), spine (p = 0.03), and pelvic (p = 0.003) injuries. Central nervous system (CNS) injury in children was a strong determinant of outcome: serious pediatric CNS trauma was associated with a tenfold increase in mortality. Mortality for children in the absence of CNS injury was less than 3%. Spinal injury also appeared to be a predictor of poor outcome in the pediatric population, with an associated mortality of greater than 50%. Overall, survival was age independent (82.5% of adults and 85.8% of children were survivors.(ABSTRACT TRUNCATED AT 250 WORDS)

Aggressive metastasectomy for pulmonic sarcomatous metastases: a follow-up study.

Pulmonary metastases are the primary cause of death due to bone and soft tissue sarcomas. We have previously shown that an aggressive approach and a new technique of multiple pulmonary metastasectomies have resulted in improved survival for patients with pulmonary metastases. In this follow-up study, an expanded database of patients was retrospectively analyzed to determine survivability as well as to evaluate potential prognostic indicators. Forty-nine patients, 26 of whom had osteogenic sarcoma (OGS), were evaluated. A number of patients had been referred from other institutions where their disease had been considered inoperable because it was extensive or recurrent. Using lateral thoracotomies exclusively, employment of a laser technique, and excision of minimal pulmonary parenchymal tissue, we performed aggressive metastasectomy. A mean of 3.0 thoracotomies was performed, in which an average of 10.2 nodules per thoracotomy were excised. Operative morbidity and mortality were minimal. The disease-free interval, the number of nodules resected, the number of thoracotomies performed, and the size of the nodules were evaluated as potential prognostic indicators. Statistically significant correlation could be established only for the size of the nodules resected. The 5-year survival rate for all patients was 39%; it was 24% for patients with OGS and 71% for those without OGS. Aggressive surgical resection of pulmonary metastases from bone and soft tissue sarcoma should be considered when there is control of local disease, no evidence of extrapulmonary metastasis, and adequate post-resection pulmonary reserve. The presence of bilateral, extensive, or recurrent disease is not a contraindication to thoracotomy. Aggressive resection of multiple nodules and improved chemotherapy appear to prolong survival of these patients when compared with survival rates of historical control subjects.

A new approach to the resection of pulmonary osteosarcoma metastases : results of aggressive metastasectomy

Four cases of supracondylar process of the humerus are presented. Two of the patients were asymptomatic and in one of these the supracondylar process was fractured. In a third there was median nerve compression and in the last there was ulnar nerve entrapment. The anatomical features, clinical symptoms and therapy are described. Good results were obtained after resection of the supracondylar process; neurological symptoms regressed one month after surgery.

Diagnostic open-lung biopsy after bone marrow transplantation

The development of pulmonary infiltrates is an ominous sign in the immunocompromised host (ICH). Selection of the best diagnostic and therapeutic approach is often difficult, and in part depends on the risk-to-benefit ratio of various diagnostic modalities, such as bronchoscopy, bronchioalveolar lavage, percutaneous needle biopsy, and open-lung biopsy (OLB). We reviewed our experience with OLB and bronchoscopy in a predominantly pediatric bone marrow transplantation population, and attempted to assess the frequency with which OLB results directed a therapeutic change, as well as the clinical results of any such therapeutic alteration. A retrospective chart review was conducted of 87 bone marrow transplantation recipients undergoing diagnostic OLB from 1975 to 1986. Bronchoscopic and OLB cultures, histopathologic studies, serological data, and autopsy results were all carefully examined. An assessment of therapeutic alteration as a result of OLB was made, and clinical changes attributable to an OLB-directed therapeutic alteration were sought. Ninety-four OLBs and 37 bronchoscopic examinations were performed in 87 patients. All patients had undergone bone marrow transplantation, most often for leukemia (58/87) or aplastic anemia (13/87). The mean interval from bone marrow transplantation to OLB was 106 days. There were no intraoperative complications, but minor postoperative surgical complications were frequent (incidence, 21%). Postoperative mortality, defined as a death occurring within 30 days of surgery, was 45% (39/87). Seventy-four percent of the patients (64/87) died during the course of the study, at a mean of 43 days after OLB. Most OLBs (60%) yielded a specific diagnosis, defined as the establishment of a precise cause for the infiltrate.(ABSTRACT TRUNCATED AT 250 WORDS)