Early impact of new health care legislation on the pediatric surgical experience of surgical residents

On January 1, 1994, Tennessee implemented TennCare, an insurance program for the state's medically uninsured and those who were previously covered by Medicaid. To determine how this change has affected the pediatric surgical experience of residents in training, we reviewed our institution's operative case logs from the first quarter of 1994 and compared them with logs for the first quarter of the years 1990 through 1993. Cases were classified according to urgency and necessity of surgical procedures. No significant change was noted in the number of patients having operations for the most necessary or urgent conditions, such as solid tumors or appendicitis. In contrast, the number of elective operations, principally for hernias, decreased significantly during the same period. While Tennessee's legislative change apparently has not affected the volume of urgent surgical cases, it has significantly decreased surgical residents' elective pediatric surgical experience.     

Substance use by surgical residents and students entering surgery

It has been known that the sensitive period for ocular dominance column plasticity is prolonged in animals raised under light deprivation. We tested whether this prolongation is related to a developmental change in Mg2+ block of N-methyl-D-aspartate (NMDA) receptors. Synaptic potentials were recorded intracellularly from visual cortex slices of rats whose optic nerves were blocked bilaterally by tetrodotoxin injected into the eyes for 2-4 weeks of age. In cells from normal rats, the amplitude of NMDA receptor-mediated synaptic potentials became smaller at more negative membrane potentials, and larger at more positive potentials, even at 0.1 mM [Mg2+]o. In cells from tetrodotoxin-treated rats, the voltage-dependence was significantly weaker than in cells from normal rats at 0.1 mM [Mg2+]o. Thus, Mg(2+)-block of synaptic NMDA receptors in the visual cortex may be regulated by optic nerve activity, and may thereby control the sensitivity to synaptic plasticity in an activity-dependent manner.     

Lasers in pediatric surgery

OBJECTIVE: To characterize immunologic specificity and possible antiidiotype activity of IgG anti-F(ab')2 in normal subjects as well as in patients with active and inactive systemic lupus erythematosus (SLE). METHODS: IgG anti-F(ab')2 and anti-double-stranded DNA (anti-dsDNA) were affinity isolated from immunoadsorption columns of F(ab')2 and dsDNA linked to Sepharose 4B. Affinity-purified IgG anti-F(ab')2 (APAF) and affinity-isolated IgG anti-dsDNA (APAD) were tested by enzyme-linked immunosorbent assay (ELISA) for other cross-reacting specificities including anti-Sm, anti-Sm/RNP, and anti- Crithidia binding. Anti-DNA specificity of APAF and APAD was assayed by S1 nuclease treatment of heat-denatured DNA. Rabbit antiidiotypic antisera were prepared by immunization with APAF and APAD from normal subjects and SLE patients and absorption with insolubilized human Cohn fraction II (Fr II). VL and VH regions of 5 monoclonal IgM antibodies with anti-F(ab')2/anti-DNA specificity generated by Epstein-Barr virus B cell stimulation were sequenced by polymerase chain reaction and characterized for VH and VL subgroup. APAF and APAD were also examined by high-resolution electron microscopy for possible ring forms indicative of antiidiotypic V-region interactions. RESULTS: APAF from normal subjects, representing 0.08-0.18% of serum IgG, showed striking relative concentrations of both anti-F(ab')2 and anti-DNA, as well as anti-Sm and anti-Sm/RNP ELISA reactivity. Both APAF and APAD reacting with F(ab')2 or dsDNA on the ELISA plate could be cross-inhibited by F(ab')2 or DNA in solution. Anti-DNA reactivity in normal APAF and APAD was much more sensitive to S1 nuclease treatment than similar fractions from SLE patients. Neither APAF nor APAD from controls produced positive antinuclear immunofluorescence or positive Crithidia staining, whereas these were strongly positive using SLE APAF and APAD. Absorbed rabbit antisera against normal or SLE APAF and APAD showed strong ELISA reactivity against both APAF and APAD, but no residual reactivity with normal Fr II. VL and VH sequencing of monoclonal human IgM antibodies showing both anti-F(ab')2 and anti-DNA reactivity showed relative VH3, V kappa 1 or VH1, V kappa 3 restriction. No evidence of ring forms or V-region "kissing" dimers was obtained when normal or SLE APAD or APAF was examined by high-resolution electron microscopy. CONCLUSION: IgG anti-F(ab')2 in both normal subjects and SLE patients represents a polyreactive Ig subfraction with concomitant anti-DNA, anti-Sm, and anti-Sm/RNP specificities. Anti-DNA reactivity in SLE is qualitatively different from that in normal APAD and APAF since normal APAD and APAF anti-DNA is much more sensitive to S1 nuclease digestion of denatured dsDNA. APAF and APAD share distinct V-region antigens which may be related to prominent VH3 or VH1 antigenic components. No evidence for in vivo complexing of anti-DNA and anti-F(ab')2 as ring forms or antiidiotype-IgG complexes was observed during ultrastructural studies. In both normal individuals and SLE patients, APAF may represent a small polyreactive IgG subfraction which also contains antinuclear and anti-DNA specificities.     

Same-day pediatric surgery

HL surfactant was used for vital indications in 12 newborns with respiratory distress syndrome born at 28-36 weeks weighing 1000-2500 g at birth and postgestation age of up to 48 h, without apparent congenital diseases and evident signs of intrauterine infection and with intraventricular hemorrhages no more severe than of the second degree. Control group consisted of 12 babies with similar condition treated similarly but without surfactant. Surfactant HL was administered endotracheally in a dose of 50 mg/kg twice at 12-h interval. Good effect was attained in 4 newborns, stable deterioration in 2, and no effect in 6 children. The majority of artificial ventilation values were virtually the same in both groups, but 2 days after surfactant, FiO2 was significantly lower in the controls than in experimental group (0.37 +/- 0.05 vs. 0.64 +/- 0.4, p < 0.01), and VEI was higher in the controls (0.33 +/- 0.05 vs. 0.18 +/- 0.03, p < 0.05). VR, MAP, FiO2, and oxygenation index decreased slower in the test group than in the controls. The mean duration of treatment with hypoxic gaseous mixtures and artificial ventilation of the lungs in the test vs. control group were 143 +/- 60 and 288 +/- 45 h vs. 45.5 +/- 8.3 and 200.8 +/- 28.5 h, respectively. The incidence of air leakage syndrome was 83% (10 cases) in the test group and 17% (2 cases) in the control group, chronic pulmonary diseases developed in 3 (25%) babies in the test and in 1 (8.3%) in the control group. Seven (67%) children in the test group developed obstructive changes in the lungs vs. 1 child in the control group. One child (test group) died from causes other than pulmonary. Hospital stay was longer in the test group than in control (14.8 +/- 1.7 vs. 8.3 +/- 1.3 days, p < 0.01).     

Changes in circadian rhythm of blood pressure in on-call pediatric residents

To provide an objective measure of the effects of on-call stress on the blood pressure (BP) of a group of pediatric residents, we used a SpaceLabs Ambulatory Blood Pressure Monitor (ABPM) to compare 37 pediatric residents' on- and off-call BPs. Residents wore the ABPM for 24 h (once on call and again off call) to assess systolic and diastolic BPs every 30 min during the day and hourly overnight. We found significantly higher MESOR (an acronym for midline estimating statistic of rhythm, which yields a mean value more representative of the true mean than an average of a series of measurements) BPs and BP loads (%BP readings > 135 mm Hg for systolic and/or 85 mm Hg diastolic) during the on-call period. Some residents became hypertensive on call, and the normal 24-h pattern of lower nighttime blood pressures was altered during this period. ABPM monitoring may prove useful in evaluating the effectiveness of interventions to reduce the stress of residency training.     

Hospital ambulatory pediatric surgery

Since 1990, we have been conducting ambulatory pediatric surgery in an unit established solely for this purpose, supported by a team of kindergarten teachers, pediatric nurses, anesthesiologists and pediatric surgeons. This prospective investigation includes all ambulatory pediatric operations performed in our department from 1990 to 1995. In this time 3665 infants and children between the ages of 6 weeks and 18 years underwent an ambulatory operation. The ratio male to female was 4.1 to 1. The series consists of 1400 inguinal hernias, 722 inguinal testes, 191 hydroceles/funiculoceles, 75 umbilical hernias, 667 phimoses, 70 meatotomies, 59 hemangiomas, 217 endoscopies and 264 other surgical procedures. Postoperative complications defined as secondary hemorrhage, fever, obvious vomiting, urine retention and laryngospasm upon terminating anesthesia accompanied by subsequent vomiting occurred in 59 (1.6%) of all infants and children. Wound infections were seen in 0.48% (17/3517) of all patients. The recurrence rate for inguinal hernias were 0.79% and 1.12% for inguinal testes. Our experience enables us to summarize that a variety of pediatric operations can be performed today as ambulatory procedures. Nevertheless one must be prepared for the occurrence of complications and always have capacities free for inpatient care where adequate observation and treatment are available. Further improvement is necessary in quality management. In the last 20 years only a few data have been published about recurrence rates after pediatric ambulatory operations for inguinal hernias and inguinal testes. Therefore we started a prospective long- term study.     

Applications of endoscopic surgery in pediatric patients

Although the advent of endoscopic technology is expanding the fields of reconstructive and aesthetic surgery in adults, there have been few reports of the use of this technology in the pediatric population. Because of their minimally invasive nature, yet wide range of exposure, endoscopic techniques have much appeal for this age group. Here we present our experience with endoscopic pediatric plastic surgery. From February of 1995 to August of 1997, 104 patients underwent 139 procedures utilizing 5- and 10-mm endoscopes. There were 58 male and 46 female patients. The mean age at surgery was 5.6 years (range, 3 weeks to 19 years). The most common type of procedures performed were insertion of tissue expanders (n = 34), excision of benign head and neck masses (n = 27), torticollis release (n = 20), excision of vascular lesions (n = 13), and miscellaneous procedures, (n = 10). There were 26 complications in 139 procedures (19 percent). Seventeen (65 percent) were in the tissue expander group. The rest were scattered among the groups with other diagnoses. Although there did not appear to be a specific type of complication associated with endoscopy, 77 percent occurred in the first 2 months of our study. This suggests a relatively steep technical learning curve. These results demonstrate that endoscopic techniques are eminently applicable in the pediatric population, providing the benefits of small and remote incisional wounds, with complication rates that are comparable with those of conventional open surgical treatment.     

Sonographic examination of abdominal trauma by senior surgical residents

The role of lysozyme in the immune immobilisation of Treponema pallidum is not yet fully understood. The T. pallidum immobilisation assay was used to demonstrate that the immobilisation and lysis of T. pallidum in vitro by antibodies (serum, IgG fraction or IgM fraction) and complement proceed in a lysozyme-independent mode. In the presence of lysozyme the rate of immobilisation increased. In contrast with its effect on Escherichia coli, the effect of lysozyme on T. pallidum was governed exclusively by its enzymic activity rather than by the cationic protein nature of the molecule. Lysozyme, released from stimulated phagocytes, induced formation of lysozyme antibodies in 59.6% of syphilis patients as determined by lysozyme antibody ELISA. The highest frequency was found in patients with untreated secondary syphilis, whereas untreated primary syphilis was only rarely accompanied by the presence of lysozyme antibodies. Cross-reactivities between lysozyme and treponemal antigens were excluded by immunoblotting. The autoantibodies did not influence the lysozyme activity. It was concluded that the formation of lysozyme antibodies is only an epiphenomenon in the host defence against treponemal infection.     

Ability of pediatric residents to read critically research papers]

PURPOSE: To compare the response rates, toxicities and survival durations of elderly patients (70 years of age or more) with those of younger patients (less than 70 years of age) with non-small-cell lung cancer (NSCLC) treated with cisplatin-based chemotherapy. PATIENTS AND METHODS: We analyzed retrospectively the data of 203 assessable patients entered on a prospective randomized trial of cisplatin-based combination chemotherapy. Chemotherapy consisted of three dosage regimens: (1) vindesine and cisplatin (VP); (2) mitomycin, vindesine and cisplatin (MVP); or (3) etoposide and cisplatin alternating with vindesine and mitomycin (EP/VM). RESULTS: A greater proportion of elderly patients had localized disease and more squamous cell carcinoma than non-elderly patients. The overall response rates were 44% in the elderly group and 28% in the non-elderly group. In the EP/VM arm, the response rate was significantly better in the elderly group than in the non-elderly group. The frequency of grade 4 leukocytopenia in the MVP and EP/VM arms in the elderly group was significantly greater than in the non-elderly group (P < 0.05). No differences were found in nonhematological toxicities between the two groups. There was no difference in overall survival between the groups. CONCLUSION: Elderly patients treated with mitomycin-containing regimens have higher hematologic toxicities than younger patients. The results of this study are consistent with the previously reported pharmacologic data on mitomycin suggesting altered pharmacokinetics in elderly patients. The improved response rate in the elderly patients was probably because more elderly patients had earlier disease, squamous cell carcinoma and better performance status. Cisplatin-based chemotherapy was tolerable for most elderly NSCLC patients with good performance status.     

Teaching medical ethics to orthopaedic surgery residents

Orthopaedic surgery residents will be faced with a variety of ethical issues when they enter clinical practice. A previous survey suggested that they lack knowledge about how to approach several types of medical ethics dilemmas. We developed a medical ethics curriculum for orthopaedic surgery residents and presented it over a one-year period to the residents in one training program. The effect of the educational intervention on the residents' knowledge of medical ethics and their ability to handle hypothetical situations was measured by comparing their responses to a questionnaire, administered before and after the intervention, with those of residents in a training program in which the intervention was not provided. The twenty-five residents at the site of the educational intervention had a mean improvement of 0.10 in the overall score, from a mean score of 0.71 on the baseline survey to a mean score of 0.81 on the follow-up survey. This improvement was significantly greater than the mean improvement of 0.02 for the thirty residents at the control site, who had a mean score of 0.72 on the baseline survey and a mean score of 0.74 on the follow-up survey (p = 0.002). Six residents who participated in the medical ethics curriculum rated it as very useful; seventeen, as somewhat useful; one, as slightly useful; and one, as not at all useful. A medical ethics curriculum can increase orthopaedic residents' knowledge of medical ethics. Whether this curriculum also will lead to behavioral changes requires additional evaluation.     

Minimally invasive pediatric cardiac surgery

We quantitatively studied the role of periosteum and bone marrow-endosteum during lengthening in 18 growing rabbits, comparing four surgical procedures: 1) periosteum and bone marrow preservation, 2) periosteum preservation, bone marrow destruction, 3) periosteum destruction, bone marrow preservation, 4) periosteum and bone marrow destruction. An external fixator was set on one femur, the other serving as a control. Distraction began on day 5 and stopped on day 25 (0.25 mm/12 hours). On day 30, femora were harvested with a layer of muscle. Area, bone mineral content and density were measured by dual-energy x-ray absorptiometry. Procedure 2 showed the highest increase in bone mineral content around the elongated callus (127%) compared to procedures: 1 (81%), 3 (25%) and 4 (-8%, i.e., resorption of bone ends). A statistically significant effect on bone formation was observed when preserving (vs. destroying): 1) periosteum, 2) bone marrow (effect observed only around the distraction gap), 3) periosteum and bone marrow in combination. Periosteum alone forms a larger callus, with more mineral content than bone marrow alone, and destruction of both results in the absence of bone formation around the distraction area. Careful preservation of periosteum is essential to bone healing. Formation of bone with a large mineral content does not require bone marrow preservation, but there is an interaction effect on healing between bone marrow and periosteum.     

Resorbable plate fixation in pediatric craniofacial surgery

Resorbable bone plates composed of a copolymer of polylactic and polyglycolic acids stabilized into position with metallic microscrews were used in the reconstruction of pediatric craniofacial deformities. In 100 patients between 4 and 15 months of age, a total of 912 resorbable plates were implanted over a 2 1/2-year period. Their application was simple and rapid and required no special instrumentation. Currently, 85 patients are more than 1 year postimplantation, which is the known time for complete resorption of this copolymeric compound. No complications have been seen with this use, including infection, overlying soft-tissue reactions, reconstructive instability, or underlying osteolysis around the screws, as determined by postoperative plain radiographs at 6 months and 1 year postoperative time periods. Four patients have had screws removed due to either palpability or secondary reconstructive surgery between 9 and 18 months postoperatively, all of whom exhibited complete polymer resorption and normal bone healing. These clinical results demonstrate the safety and effectiveness of this copolymeric material for pediatric craniofacial applications.     

The place of laparoscopy in pediatric surgery]

Histopathological features of Alzheimer's disease (AD) include extracellular deposits of amyloid beta (A beta) fibrils in the cores of senile plaques, intracellular neurofibrillary tangles (NFT) which are composed of paired helical filaments (PHF), and neuronal cell loss. The main component of PHF is highly phosphorylated tau protein. We identified a protein kinase converting normal tau into a PHF-like state. The kinase is tau protein kinase (TPK) I/glycogen synthase kinase (GSK)-3 beta. Using a neuronal cell culture system as an AD model, it was recognized that TPK I/GSK-3 beta plays a central role in AD pathology. We hypothesize that A beta-induced neuronal cell death occurs by the following mechanism. A beta inactivates PI3-kinase and activates TPK I/GSK-3 beta, which in turn phosphorylates and inactivates both tau and pyruvate dehydrogenase (PDH). After the ability of tau to promote microtubule assembly is diminished by phosphorylation, soluble tau molecules aggregate into PHF by an unknown mechanism. Destabilization of microtubule arrays causes inhibition of axonal transport and accumulation of amyloid precursor protein (APP). Phosphorylation of PDH inhibits the reaction converting pyruvate to acetyl-CoA, resulting in inhibition of energy metabolism and a decrease in acetylcholine, both of which are also characteristics of AD. These changes may lead to neuronal cell death.