Yield of bronchoalveolar lavage in ventilated and non-ventilated children after bone marrow transplantation

A study was undertaken to retrospectively evaluate the yield of bronchoalveolar lavage (BAL) in a single-institution series of children after bone marrow transplantation (BMT) and to compare the yield of BAL between the ventilated and nonventilated patients. We reviewed charts of 52 consecutive children after BMT who underwent BAL. Thirty patients (41 BALs) were nonventilated (group 1) and 33 patients (45 BALs) were ventilated for respiratory failure (group 2). Eleven patients were included in both groups. BAL was performed a median of 255 and 28.5 days after BMT in groups 1 and 2, respectively (P < 0.001). Group 1:17 pathogens were isolated from 13 BALs; a single pathogen from 10 BALs. Group 2:15 pathogens were isolated from 14 BALs (31.1% positive). Viruses were isolated from 13 BALs in group 2. A severe complication of BAL occurred in only one patient from group 1 (1.1%). Open lung biopsies were performed in one patient in group 1 and eight patients in group 2. The histological findings correlated with the BAL findings in 66.7%. In conclusion, there was no difference in the yield of BAL between the groups. Therapy was changed in one third of the patients dictated by the BAL findings. The risk of severe complications was relatively low. A good correlation between open lung biopsy (OLB) and BAL was found.

Superantigens and cystic fibrosis: resistance of presenting cells to dexamethasone

Staphylococcus aureus, a common pulmonary pathogen in cystic fibrosis (CF), produces exotoxins that are extremely potent superantigens. A number of animal studies have shown that superantigens cause pulmonary inflammation, but the possible role of superantigens in CF has not been investigated. The present study assessed possible differences between control and CF B cells in presenting superantigens to T cells. Immortalized B-cell lines were used as superantigen-presenting cells to avoid environmental influences (e.g., infection or antibiotics) common to freshly isolated cells. The results show that CF B-cell lines presented a staphylococcal superantigen to the immortalized T-cell line (Jurkat) as effectively as did control B-cell lines as measured by interleukin-2 production. However, in contrast to the case for control B-cell lines, dexamethasone did not inhibit CF B-cell lines from presenting superantigen. The resistance of superantigen-presenting CF B cells to corticosteroids suggests that the pulmonary response to superantigens may be poorly regulated in CF, leading to an exaggerated inflammatory response to S. aureus.

Hemophagocytic lymphohistiocytic syndrome: Unrecognized cause of multiple organ failure

OBJECTIVE: To describe an often-unrecognized clinical picture of multiple organ failure in hemophagocytic lymphohistiocytic syndrome (HLS). DESIGN: Retrospective chart review. SETTING: A ten-bed pediatric intensive care unit (PICU) in a tertiary children's university hospital. PATIENTS: A total of 11 children (age, 5 months to 13 yrs) who fulfilled the criteria for the diagnosis of familial- or infectious-associated hemophagocytic lymphohistiocytosis and who required intensive care support for organ failure. INTERVENTION: None. MAIN RESULTS: During a 10-yr period, 5,439 children were hospitalized in our PICU. A total of 11 children were diagnosed as suffering with HLS. Of these 11 patients, three (27%) had the familial form and eight had the infectious-associated form. After admission to the PICU, seven patients (63%) were diagnosed as suffering with HLS and each had one or more organ failures (patients 3-7, 9, and 10). All presented with fever, hepatomegaly, and splenomegaly; in addition, all had at least two of the following: anemia, neutropenia, or thrombocytopenia. All 11 had lymphohistiocytic accumulation in bone marrow (n = 10), lymph node (n = 2), lung (n = 2), and/or liver (n = 1). Organ failure was noted most often in the respiratory system (n = 7) attributable to severe, acute respiratory distress syndrome and pleural effusion. Of the 11 patients, six had cardiovascular involvement that manifested as shock in three and as capillary leak syndrome in three. Renal failure occurred in four patients. Of these, two required hemodiafiltration and one required peritoneal dialysis. Liver failure occurred in three and central nervous system involvement and coma in three. Most of the patients required massive therapeutic intervention, including assisted ventilation (n = 6), inotropic support (n = 3), and hemofiltration (n = 3). A total of seven patients (63%) died. CONCLUSIONS: Hemophagocytic lymphohistiocytic syndrome in the pediatric population may have a dramatic clinical picture, with multiple organ failure as a presenting symptom or early in the disease course, mandating intensive support in the PICU.

Cytokine response during hyperoxia: sequential production of pulmonary tumor necrosis factor and interleukin-6 in neonatal rats

BACKGROUND

Exposure of newborn animals to high concentrations of oxygen leads to diffuse alveolar damage similar to that seen in bronchopulmonary dysplasia in human infants. Therefore, neonatal rats are a suitable practical model of hyperoxic lung damage in human infants.

OBJECTIVE

To determine the involvement of tumor necrosis factor-alpha and interleukin-6 in lung injury in neonatal rats exposed to 100% O2 concentration.

METHODS

A randomized controlled study was designed in which litters of term Sprague-Dawley rat pups were assigned to experimental or control groups. The pups in the experimental group were placed in 100% O2 from birth for 9 days, while the control pups were placed in room air. Twelve to 15 pups from each group were sacrificed on day 1, 3, 6, 9 and 13 after birth for bronchoalveolar lavage collection and lung histologic study. The bronchoalveolar lavage fluid was assayed for TNF alpha and IL-6.

RESULTS

Newborn rats exposed to 100% O2 for the first 9 days of life showed severe pulmonary edema and hypercellularity on days 1 and 3, which then improved to nearly complete resolution on days 6 and 9. Pulmonary TNF alpha was produced early on O2 exposure (day 3) and pulmonary IL-6 later (days 6 and 9).

CONCLUSIONS

Hyperoxia induces sequential production of pulmonary TNF alpha and IL-6, which corresponds to the severity of the pathological findings and the known inflammatory and anti-inflammatory role of these cytokines.

Open lung biopsy--successful diagnostic tool with therapeutic implication in the critically ill paediatric population

Open lung biopsy (OLB) is an important diagnostic tool in children with immune deficiency and/or chronic lung disease with diffuse pulmonary compromise. These patients require a tailored therapeutic approach owing to their fragile status and the side effects of unnecessary or inadequate treatment. Twenty-six patients of mean age 5.6 y underwent 41 open lung biopsies in our centre between 1991 and 1995. Seventeen (65%) were immunocompromised (including 13 with malignancy) and 9 had other lung diseases. The biopsies were diagnostic in 25 patients (96%), and complete clinical-pathological correlation was found in 11 (42%). A specific infectious aetiology was detected in nine patients (35%), all of them immunocompromised. Therapeutic changes were instituted on the basis of the biopsy findings in 18 patients (69%). Two patients had postoperative complications (prolonged pleural leak). We conclude that OLB is a safe diagnostic procedure even in the critically ill child and should be employed without hesitation when conventional methods fail to provide a definitive diagnosis to help redirect therapy.

Prolonged croup due to herpes simplex virus infection

Herpes simplex virus (HSV) is an uncommon cause of acute laryngitis in immunocompetent patients since it mostly occurs in immunocompromised subjects. We present two previously healthy children with prolonged gingivostomatitis and stridor (lasting 3 and 4 weeks) in whom HSV-1 was isolated from subglottal ulcers.

CONCLUSION

HSV should be considered a possible pathogen in cases of prolonged or atypical croup not only in immunocompromised or elderly patients but also in otherwise healthy children.

Interleukin-6 levels in serum and lung lavage fluid of children undergoing open heart surgery correlate with postoperative morbidity

OBJECTIVE

To evaluate the relationship of perioperative levels of interleukin 6 (IL-6) in serum and bronchoalveolar fluid with morbidity and mortality in children undergoing cardiopulmonary bypass (CPB).

DESIGN

Prospective, noninterventional study.

SETTING

Operating room and pediatric intensive care unit (PICU) of a university hospital.

INTERVENTIONS

None.

MEASUREMENTS AND RESULTS

IL-6 levels were measured in serum and lung lavage fluid obtained before, during, and after CPB using the B9.9 bioassay. Alveolar epithelial lining fluid (AELF) volume was calculated using the urea correction method. Mean intraoperative AELF IL-6 levels increased fourfold compared to preoperative levels, and mean serum IL-6 levels increased fivefold after CPB. Mean intraoperative AELF IL-6 levels correlated with intraoperative blood transfusion (r2 = 0.18; p = 0.049) and duration of inotropic support (r2 = 0.29; p = 0.009), mechanical ventilation (r2 = 0.24; p = 0.019), and PICU stay (r2 = 0.29; p = 0.008). Mean serum IL-6 levels 2 h after CPB correlated with intraoperative blood transfusion (r2 = 0.3;p = 0.007), and with Pediatric Risk of Mortality score on postoperative day 3 (r2 = 0.24; p = 0.022), and were higher in patients with massive fluid retention (p = 0.014) and in nonsurvivors (p = 0.003).

CONCLUSIONS

Serum and alveolar IL-6 levels increase after CPB, and correlate with postoperative morbidity. Serum IL-6 levels also correlate with mortality. They may be useful in assessing the severity of the systemic inflammatory response after CPB.

Experimental use of raffinose as an osmotic agent for peritoneal dialysis

Conventional glucose-based solutions for peritoneal dialysis fluids have been shown to raise problems of biocompatibility. We therefore evaluated the ultrafiltration capabilities of raffinose as an alternative osmotic agent in a non-uremic rat model. Animals were divided into four groups and injected intraperitoneally with solutions containing raffinose (4.5%, 345 mOsm/kg; 16.7%, 518 mOsm/kg) or glucose (1.5%, 346 mOsm/kg; 4.25%, 489 mOsm/kg). Data obtained from animals exposed to 16.7% raffinose were excluded because of precipitation of the osmotic agent. Low-osmolality raffinose solution induced higher ultrafiltered volume than the low-osmolality glucose-enriched fluid at 120 minutes of dwelling time. No significant differences were observed in effluent sodium and potassium concentration and protein dialysate-to-plasma (D/P) ratio. The D/P ratio of phosphate was higher in the low-osmolality raffinose-based fluid than in the low-osmolality glucose solution. The osmolality of the solutions was significantly decreased after a dwelling time of 120 minutes. We conclude that 4.5% raffinose is an effective osmotic agent. Total or partial replacement of glucose by raffinose for clinical peritoneal dialysis could be eventually considered after appropriate evaluation of its biocompatibility and general side effects.

Sclerosing encapsulating peritonitis

Sclerosing encapsulating peritonitis (SEP), idiopathic or secondary, is a form of intraperitoneal fibrosclerosis that causes intestinal obstruction. In the case of a 41-year-old man with dialysis-induced SEP presented here, we show that intraperitoneal hemorrhage may play an important pathogenetic role and that the process may develop in < or = 12 weeks. Regardless of cause, the treatment of obstruction is operative, with dissection of the encasing membrane from the intestine and separation of adherent loops of small bowel until they are laid free and returned to their normal configuration. The prognosis after appropriate operative therapy is good but depends on coexisting diseases.

Laryngomalacia: a cause for early near miss for SIDS

Six infants had recurrent apnea of infancy episodes (near miss sudden infant death syndrome) during their neonatal period. Physical examination and laboratory investigation were normal. Polygraphic sleep monitoring revealed recurrent obstructive sleep apnea. These infants underwent fiberoptic endoscopy which showed that airway obstruction occurred at the laryngeal orifice as a result of laryngomalacia. It is suggested that laryngomalacia may be a cause for early apnea of infancy.

Exercise tolerance of end-stage renal disease patients

The purpose of this study was to evaluate the exercise tolerance of end-stage renal disease patients, and to examine pulmonary function and blood lactate as its possible limiting factors. Ten end-stage renal disease patients (age 30 +/- 11) were tested at rest and in a subsequent graded treadmill test to exhaustion. Velocity was 4.8 km/h and the grade was incremented by 2.5% every 4 min. One minute of rest, used for blood sampling, separated successive stages. Pulmonary functions (FVC, FEV1) at rest were both 76% of predicted. Resting heart rate, systolic and diastolic blood pressures, and ventilatory equivalent values were higher than normal. At peak exercise, heart rate, oxygen uptake, oxygen pulse and blood lactic acid were lower than normally predicted for maximal exercise, while ventilatory equivalent and diastolic blood pressure were higher. Only six patients reached blood lactate levels beyond 4 mM.l-1 (onset of blood lactic acid), at which point they utilized 88 +/- 5% of their respective peak Vo2. The results suggest that the low exercise tolerance demonstrated in end-stage renal disease patients is not limited by the somewhat compromised pulmonary capacity or by excessive blood lactate levels.

Intraperitoneal phosphate administration in hungry bone syndrome

Hypophosphatemia complicating parathyroidectomy for secondary hyperparathyroidism in renal failure is usually corrected by the oral or intravenous routes. We present a case in which those methods of treatment were not possible, and the phosphate was administered intraperitoneally. Phosphate was added as one molar sodium diphosphate solution to the dialysis fluid. In our case the procedure was well tolerated, phosphate blood levels were rapidly corrected, no alterations in calcium, magnesium or other parameters were detected and the patient was discharged in good condition. In selected cases of hungry bone syndrome after parathyroidectomy, intraperitoneal phosphate can be used safely.

Adaptive myocardial hypertrophy in the renal ablation model

We have previously reported downregulation of the vascular alpha 1-receptor in the 5/6 renal ablation model. In this investigation we have examined the adaptive response of the heart following 5/6 renal ablation. Renal ablated and sham rats were maintained under identical conditions for 6 weeks. Despite the presence of systemic hypertension in renal ablated rats (185 +/- 10 mm Hg, P less than .01), heart weight did not differ from sham. [125I] +/- CYP binding was performed and myocardial norepinephrine (NE) content determined to evaluate myocardial sympathetic neuroeffector mechanisms. Scatchard analysis and 1-isoproterenol competition curves did not reveal a difference in the binding properties of the myocardial beta-receptor. No difference in myocardial NE was found in renal ablated and sham rats. Unexpectedly, 1-isoproterenol stimulation of adenylate cyclase was impaired in renal ablated rats (32.6 +/- 6 v 58.6 +/- 5 pmol/mg/min, P less than .01) and the dose response curve shifted to the right. We conclude that despite systemic hypertension an adaptive hypertrophic response was not present in hearts of renal ablated rats; myocardial sympathetic neuroeffector mechanisms are not altered in this model; and impaired stimulation of adenylate cyclase appears to be the result of a post-receptor defect.

The prevalence of high insertion of scrotum, hydrocele and mobile testis in the newborn infant (36-42 weeks gestation)

The prevalence of some minor abnormalities of the male genitalia was studied in 271 boys born over a period of 2 months. The scrotal insertion on the ventral side of the penis was determined in an objective manner by measuring the ratio of the ventral and dorsal length of the unstretched penis. A scrotal insertion ratio of less than 0.48 defined high insertion of the scrotum which was found in 2.7% of our newborn infants. This anatomical finding has an important clinical significance for the performance of early circumcision. The prevalence of hydrocele in all male newborn infants was 57.9%. Extravaginal (communicating) type was present in 86% of all infants, intravaginal (noncommunicating) in 9.5%, while both types of hydrocele in the same neonate was observed in 4.5%. The relatively high frequency of mobile testes (22%) is of interest. The natural history of this entity is not fully understood and the question of follow-up remains open.

Amelioration of systemic hypertension by converting enzyme inhibition in the renal ablation model

Hypertension associated with a reduction in renal mass has been traditionally thought of as a volume-dependent state. Recent investigations suggest important roles for systemic and glomerular resistance vessels in the pathogenesis of systemic hypertension (SHT) and progression of end-stage renal disease. To examine this relationship, investigations were performed in two groups of rats maintained for 6 weeks following 5/6 renal ablation. Group A received converting enzyme inhibition (CEI) for 6 weeks. Group B received no treatment. Systolic blood pressure and weight of remnant kidney tissue were both increased in group B (P less than 0.01). BUN did not differ in groups A and B; however, renal PGI2 excretion was increased in group A (P less than 0.01). Renal morphology was preserved in group A, with little or no evidence of glomerular sclerosis. CEI prevents SHT and enhances renal PGI2 excretion in this model. The selective increase in PGI2 may mediate systemic and renal effects of this agent.

Myocardial hypertrophy: the effect of sodium and the role of sympathetic nervous system activity

Dietary sodium and the myocardial alpha 1-receptor have been implicated in the hypertrophic response of myocardial tissue. Alterations in sodium homeostasis have been demonstrated to influence sympathetic nervous function, centrally and peripherally. In this investigation, we have examined the effect of dietary sodium on the development of myocardial hypertrophy; and the role of sympathetic neuroeffector mechanisms in the hypertrophic response. Studies were performed in three groups of uninephrectomized rats: A-regular diet; B-1% saline/regular diet; C-1% Saline/doca/regular diet. Groups A and B did not develop systemic hypertension (SHT). Saline treatment increased heart weight and the density of surface alpha 1-receptors; myocardial norepinephrine (NE) was reduced. Group C developed SHT. Heart weight was greatest in Group C; and myocardial NE was severely depleted. Downregulation of myocardial alpha 1-receptors, a finding consistent with the hyperadrenergic state, was observed in Group C. Our results suggest dietary sodium may modulate hypertrophic response in myocardial tissue, by altering sympathetic neuroeffector mechanisms.

Upregulation of the vascular alpha-1 receptor in malignant DOCA-salt hypertension

In this investigation we describe regulation of the vascular alpha-1 receptor and functional properties of resistance vessels in malignant hypertensive DOCA-salt rats (DOCA-salt). Uninephrectomized control and DOCA-salt rats were maintained for 6 weeks; microscopic renal morphology provided an index of vascular injury. Radioligand binding studies indicated a striking increase in the density of mesenteric alpha-1 binding sites in DOCA-salt (542 +/- 44 fm/mg) vs. salt control (206 +/- 4 fm/mg) and water control (223 +31 fm/mg) P less than .01. The affinity of the receptor for the radioligand [125I] (+/-) BE 2254 was reduced in DOCA-salt rats. Electrical nerve stimulation and agonist dose response curves were performed on isolated perfused mesenteric arteries. A singular correlation between increased receptor density and vascular responses in DOCA-salt rats could not be demonstrated. The norepinephrine (NE) content of mesenteric arteries was reduced in DOCA-salt (1001 +/- 32 ng/g) vs. water control (1522 +/- 44 ng/g) and saline control (1538 +/- 30 ng/g) P less than .01. Our results indicate, upregulation of the mesenteric alpha-1 receptor occurs in DOCA-salt rats, however, additional factors participate in the vascular response to adrenergic stimulation in this model.

Externally applied abdominal vibration as a method for improving efficiency of peritoneal dialysis

We studied the effect of externally applied vibration onto the abdominal wall on the efficiency of peritoneal dialysis (PD). Ten patients were studied. Three consecutive PD exchanges (control sessions, CS) were compared with vibration sessions (VS). Samples of blood and dialysate were analyzed for urea nitrogen (UN), creatinine (Cr) and potassium (K). Mean clearance was calculated. We found that vibration increased significantly the mean UN, Cr and K clearances.

Effect of chronic uremia on the cardiovascular alpha 1 receptor

Adrenergic dysfunction in uremia has been well described. Several lines of evidence suggest disorders of blood pressure regulation and myocardial response may occur secondary to adrenergic dysfunction; attenuated pressor response to norepinephrine (NE) in uremia; attenuated chronotropic responses during dialysis induced hypotension. Since the adrenergic receptors are the effector component of the adrenergic nervous system, we have employed the partially nephrectomized uremic rat, to examine the effect of chronic uremia (4-6 weeks) on the binding properties of alpha 1 receptors in rat mesenteric artery and myocardial tissue. The results indicate that moderate levels of uremia alter the binding properties of both the alpha 1 vascular and myocardial receptor.