Bedside placement of pH-guided transpyloric small bowel feeding tubes in critically ill infants and small children.

BACKGROUND AND METHODS: The small bowel of critically ill infants and small children was cannulated using a soft feeding tube with a pH sensor at the distal tip. By monitoring pH, the tubes were guided through the stomach into the small bowel. RESULTS: Successful placements were performed in 36 of 37 (97%) attempts in 29 critically ill patients whose age was 7.9 +/- 6.3 months and weight was 5.9 +/- 2.6 kg. Continuous jejunal feedings were administered for 3.7 +/- 3.1 weeks without difficulties or complications in all but one patient. CONCLUSION: pH-guided jejunal tube placement provides a safe, easy bedside alternative to fluoroscopic, endoscopic or surgical placement in critically ill infants and small children.

Multiple organ failure after ingestion of pennyroyal oil from herbal tea in two infants.

BACKGROUND: Hepatic and neurologic injury developed in two infants after ingestion of mint tea. Examination of the mint plants, from which the teas were brewed, indicated that they contained the toxic agent pennyroyal oil. METHODS: Sera from each infant were analyzed for the toxic constituents of pennyroyal oil, including pulegone and its metabolite menthofuran. RESULTS: Fulminant liver failure with cerebral edema and necrosis developed in the first infant, who died. This infant was positive only for menthofuran (10 ng/mL). In the other infant, who was positive for both pulegone (25 ng/mL) and menthofuran (41 ng/mL), hepatic dysfunction and a severe epileptic encephalopathy developed. CONCLUSION: Pennyroyal oil is a highly toxic agent that may cause both hepatic and neurologic injury if ingested. A potential source of pennyroyal oil is certain mint teas mistakenly used as home remedies to treat minor ailments and colic in infants. Physicians should consider pennyroyal oil poisoning as a possible cause of hepatic and neurologic injury in infants, particularly if the infants may have been given home-brewed mint teas.

Diazepam and intubation in emergency treatment of seizures in children.

STUDY OBJECTIVES: This study was undertaken to determine the incidence of endotracheal intubation after the use of diazepam compared with phenobarbital or phenytoin in emergency treatment of seizures in children. DESIGN: The records of all children (98) were reviewed in a case-control fashion. A logistic regression model was used to determine whether there was an association between diazepam administration and intubation, adjusting for all other covariates (age, weight, convulsion time before first anticonvulsant was given, response latency, diagnosis, and therapy). SETTING: All children were treated in an emergency department and then transported to a tertiary pediatric center by a pediatric transport team. TYPE OF PARTICIPANTS: All patients were children, with a median age of 2.7 years (range 0.17 to 15.3 years). INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Only the use of diazepam was found to be significantly associated with intubation after adjusting for all other covariates (adjusted odds ratio, 49.4; P less than .001). In the comparison of diazepam versus phenobarbital or phenytoin used as the first anticonvulsant, median response latency did not differ (27.0 vs 32.5 minutes, P greater than .83). CONCLUSION: A significant association was found between diazepam use and intubation. Response latency was not shorter when diazepam was used as the initial anticonvulsant compared with phenobarbital or phenytoin.

Use of H2-receptor antagonists in children.

H2-receptor antagonists (H2RAs) have evolved into the mainstay of anti-acid therapy for pediatric patients, replacing antacids and other modes of therapy. Much of the experience and data used for therapeutic decisions in children, however, have been extrapolated from adult studies. Ranitidine and cimetidine have been studied most extensively in the adult and pediatric populations. Both raise gastric pH and achieve other therapeutic endpoints; however, cimetidine appears to have a greater frequency of both adversed effects and drug interactions. H2RAs are the preferred agents for prevention of stress ulcers, ulcer disease, and reflux esophagitis in the pediatric population.

Determination of triacylglycerol lipase activity using carbon-13-labeled triacylglycerols and nuclear magnetic resonance spectroscopy: evidence that hepatic lipase hydrolyzes medium-chain triacylglycerols.

Triacylglycerol lipase activity was studied using glycerol [1-13C]trioctanoate mixed with postheparin rat plasma. 13C NMR spectroscopy demonstrated triacylglycerol hydrolysis into free fatty acids with no difference at the 1,3 or 2 glycerol positions. There was no inhibition by high sodium concentration, consistent with lipase of hepatic origin.

Adipose tissue abnormalities in cystic fibrosis: noninvasive determination of mono- and polyunsaturated fatty acids by carbon-13 topical magnetic resonance spectroscopy.

Natural abundance in vivo carbon-13 topical magnetic resonance (TMR) spectroscopy was used to assess human adipose tissue stores of essential (polyunsaturated) fatty acids. TMR spectra were obtained from 17 normal volunteers and nine cystic fibrosis patients using an Oxford TMR-32 with a surface coil that sampled tissue less than 1 cm below the surface of an extremity. Spectra were taken of lower leg adipose tissue. Polyunsaturated fatty acid content was determined by comparing peak heights of the polyunsaturated peak (internal unsaturated carbons, 128 ppm) to C-1 carboxyl groups (173 ppm). Monounsaturated fatty acid content was determined by subtracting the polyunsaturated peak from the peak observed for all unsaturated carbons (external unsaturated carbon, 130 ppm) and dividing this ratio by the carboxyl peak. In vivo TMR of normal volunteers resulted in observed polyunsaturated fatty acid content of 17.8 +/- 2.1% and a monounsaturated content of 44.8 +/- 3.8%. The polyunsaturated and monounsaturated fatty acid content of adipose tissue from the cystic fibrosis patients was 15.0 +/- 2.0% (p less than 0.005 versus normal volunteers) and 47.8 +/- 6.5% (NS), respectively. One cystic fibrosis patient without fat malabsorption had decreased adipose polyunsaturates, whereas another patient on high calorie gastrostomy feeds had normal levels. Carbon-13 TMR spectroscopy is a sensitive, noninvasive technique for determining essential fatty acid status in subcutaneous adipose tissue of patients with cystic fibrosis.

The noninvasive determination of linoleic acid content of human adipose tissue by natural abundance carbon-13 nuclear magnetic resonance.

A new method to assess noninvasively the proportionate storage of poly- and mono-unsaturated fatty acids in human adipose tissue is described. The method is based on in vivo natural abundance 13C NMR at 1.9 T using a TMR 32/200. Data were acquired with a concentric coil system placed below subcutaneous adipose tissue of the calf or the lower arm. Continuous single-frequency decoupling was used to optimize the signal in the spectral region of interest and minimize potential heating effects. Only adipose triglycerides contributed significantly to the resonance intensities. Typical linewidths for the in vivo 13C resonances were 10-14 Hz resulting in excellent resolution in the region of the unsaturated carbons. Signal-to-noise ratios for the resonance at 128.4 ppm (due to carbon atoms of polyunsaturated fatty acids) were typically 50-90 in 8 min using 0.25s repetition time. The relative storage of polyunsaturated fatty acids was determined by comparing the peak intensity at 128.4 ppm with the intensities of the peaks due to the carbonyl, the glycerol, or the main methyl carbons. High-resolution in vitro NMR of adipose biopsies and various mixtures of triglycerides studied with the in vivo NMR protocols provided further evidence that the described in vivo NMR methods allowed precise information on the relative storage of linoleic acid, the main constituent of the pool of polyunsaturated fatty acids. Conventional gas chromatography was performed on adipose biopsies of two volunteers and resulted in close agreement with the in vivo NMR methods. The average polyunsaturated fatty acid concentration in adipose tissue in seven healthy volunteers was 19.83 mol% +/- 1.74 (SD) as determined by in vivo NMR, consistent with conventional studies based on gas chromatography of biopsied material. Preliminary data on three cystic fibrosis patients showed a decreased polyunsaturated fatty acid concentration of 13.12 mol% +/- 2.73 (SD). The high accuracy of this method and its noninvasive character should be especially valuable in clinical research and diagnosis as repetitive adipose biopsies can be avoided.