PubMed HealthSearch

Biomedical subjects

A E Thompson

Publications and source records attributed to A E Thompson.

At least 19 recordsLinked to original sources

Validity of a disposable end-tidal CO2 detector in verifying endotracheal tube placement in infants and children.

STUDY OBJECTIVE: To examine the validity of a disposable, colorimetric end-tidal CO2 detector in verifying endotracheal tube (ETT) placement in infants and children. DESIGN: The detector was studied prospectively in 151 intubations. SETTING: Operating room, ICU, and emergency department of a children's hospital. PARTICIPANTS: One hundred thirty-seven children undergoing endotracheal intubation for anesthesia (52), respiratory support (76), or CPR (23). INTERVENTIONS: After endotracheal intubation, tube position was verified, the detector was attached, and readings were obtained. MEASUREMENTS AND RESULTS: The detector correctly identified tube position (trachea, 124; esophagus, four) in all 120 patients who were not in cardiac arrest (P less than .01). In the cardiac arrest setting, all six esophageal intubations were correctly identified, but two of the 17 tracheal intubations were incorrectly interpreted as esophageal intubations (P less than .01). CONCLUSION: The detector accurately identifies ETT position in children with spontaneous circulation who weigh more than 2 kg. During CPR, a positive test correctly indicates that the ETT is in the airway, but a negative result (suggesting esophageal placement) requires an alternate means of confirming ETT position.

Adolescent

Lung mechanics during and after extracorporeal membrane oxygenation for meconium aspiration syndrome.

OBJECTIVE: To determine whether abnormalities in lung mechanics detected in infants during the acute phase of meconium aspiration syndrome persist after treatment with extracorporeal membrane oxygenation (EMCO). DESIGN: Prospective, descriptive study. Prospective evaluation of airway function and lung mechanics during and after ECMO by pulmonary function testing at 1.8 +/- 0.5 days of EMCO (period 1), follow-up at 1.4 +/- 0.2 days (period 2), and 7.0 +/- 0.9 days (period 3) after decannulation from ECMO. SETTING: Tertiary care neonatal/pediatric ICU. PATIENTS: Twelve neonates undergoing ECMO treatment for severe meconium aspiration syndrome that was refractory to conventional mechanical ventilation. INTERVENTIONS: Maximum expiratory flow-volume curves were studied with the deflation flow-volume curve technique, and compliance and resistance of the respiratory system were studied with partial passive flow-volume curves. MEASUREMENTS AND MAIN RESULTS: Respiratory system compliance was the only index of respiratory mechanics that was significantly (p less than .05) improved (0.96 +/- 0.1 vs. 0.61 +/- 0.1 mL/cm H2O/kg) immediately after decannulation from ECMO compared with period 1. Clinically important (p less than .05) improvement in forced vital capacity (28.0 +/- 5.5 vs. 16.1 +/- 1.9 mL/kg), respiratory system compliance (1.01 +/- 0.2 vs. 0.61 +/- 0.1 mL/cm H2O/kg), and maximum expiratory flow at 25%/forced vital capacity (1.0 +/- 0.3 vs. 2.2 +/- 0.3) was evident only during period 3 compared with period 1. CONCLUSIONS: We conclude that improvements in the clinical condition and oxygenation, permitting successful decannulation from ECMO, are achieved before clinically important improvements in lung mechanics.

Acute Disease

Extracorporeal membrane oxygenator rescue in children during cardiac arrest after cardiac surgery.

BACKGROUND: Conventional cardiopulmonary resuscitation (CPR) for cardiac arrest after open-heart surgery in children is often unsuccessful despite the ability to perform open-chest massage. The purpose of this study was to review our results with mechanical support as rescue therapy in children with sudden circulatory arrest after cardiac surgery. METHODS AND RESULTS: From 1981 through 1991, we have used mechanical support with an extracorporeal membrane oxygenator (ECMO) circuit for cardiac support in 33 children. Eleven of the 33 patients (age, 15 +/- 7 months) suffered cardiac arrest intractable to conventional open-chest massage 39 +/- 15 hours after an open-heart procedure. The mean duration of CPR was 65 +/- 9 minutes until ECMO flow was started. ECMO support was continued for 112 +/- 8 hours. One patient had ECMO discontinued due to bleeding (survived); three were discontinued from ECMO and died from neurological complications; and one died of cardiac dysfunction. Sepsis on ECMO was seen in one patient (survived). Overall early survival was seven of 11 (64%) with one patient requiring heart transplantation due to irreversible cardiac dysfunction. One child died late (1 month) after ECMO support. There were no long-term sequelae in the survivors. CONCLUSIONS: We conclude that ECMO rescue in children with postcardiotomy cardiac arrest is a feasible option in selected patients even after prolonged CPR (as long as 60 minutes).

Cardiac Surgical Procedures

Utility of an end-tidal carbon dioxide detector during stabilization and transport of critically ill children.

Critically ill children often require endotracheal intubation prior to transport to a medical center. Correct endotracheal tube placement and maintenance during transport are essential. The utility of a portable colorimetric end-tidal CO2 detector during transport of critically ill children was evaluated. Fifty-eight children with spontaneous circulation (aged 1 day to 12 years, weight 0.9 to 26 kg) who underwent 59 intubations during transport by ground (n = 31) or air (n = 27) were studied. Tube position was confirmed by physical examination, arterial blood gas values, or arterial oxygen saturation, and sometimes by chest radiography. The detector was attached and readings were obtained after intubation; readings were repeated if endotracheal tube position was rechecked during transport. Fifty-seven of 58 tracheal positions and the 1 esophageal tube position were correctly identified. One false-negative result occurred in a severely hypocarbic 900-g premature newborn. On each occasion that the detector was used en route, the endotracheal tube position was correctly identified. It is concluded that the end-tidal CO2 detector is a useful tool for confirming endotracheal tube position during transport of critically ill children weighing more than 2 kg who are not in cardiopulmonary arrest.

Body Weight

Correction of ulnar drift during silastic metacarpo-phalangeal joint arthroplasty.

In previous published accounts of silastic replacement arthroplasty of the M.P. joint of the finger in rheumatoid disease, dynamic splintage has been used for up to six months after operation to ensure correction of ulnar drift. We have investigated two methods of surgical correction in a prospective trial in consecutive patients. No dynamic splintage was used. Both resulted in correction of ulnar drift from an average of 34 degrees (maximum 92 degrees) to 8 degrees (maximum 32 degrees) in 86 fingers. The two methods both corrected ulnar drift well, but crossed intrinsic transfer gave a better range of active movement and is recommended as an alternative to dynamic splintage.

Activities of Daily Living

Validity of a disposable end-tidal carbon dioxide detector in verifying endotracheal tube position in piglets.

BACKGROUND AND METHODS: the most reliable methods for confirming endotracheal tube placement are direct visualization of passage through the vocal cords and documentation of CO2 in the expired gas. We evaluated the use of a disposable colorimetric CO2 detector for verifying endotracheal tube position in small animals. The end-tidal CO2 (Petco2) detector was tested in 11 piglets with the endotracheal tube sequentially in the trachea, the esophagus, the esophagus with a carbonated beverage in the stomach, the esophagus after bag-mask ventilation. Endotracheal tube position was confirmed in all cases by direct visualization and capnometry. RESULTS: The Petco2 detector identified the tube placement accurately in all 54 (21 tracheal, 33 esophageal) intubations (p less than .001). CONCLUSIONS: This disposable Petco2 detector is highly sensitive and specific for verifying endotracheal tube placement in this nonarrest piglet model.

Animals

Ten years of extracorporeal membrane oxygenation: neurodevelopmental outcome.

Cf the 87 survivors of extracorporeal membrane oxygenation over a 10-year period, 67 participated in a follow-up study which included neurologic examination (n = 67), cognitive testing (n = 67), and audiologic assessment (n = 33). Matched control subjects for those older than 5 years were also evaluated. Outcome was defined as normal for cognitive scores greater than or equal to 85 and normal neurologic examination results, suspect for cognitive scores 70 through 84 or nonfocal neurologic findings such as hypertonia/hypotonia, and abnormal for cognitive scores less than 70 or abnormal neurologic examination results. Of the 10 school-aged children studied, 9 were normal and there were no differences in mean cognitive scores between subjects and controls (IQ subjects = 109 +/- 12 [SD], IQ controls = 107 +/- 13). For preschoolers aged 2.7 through 4.11 years, the mean cognitive score was 91 +/- 11 and 7 (70%) were normal. For infants 6 through 30 months, the mean cognitive score was 101 +/- 22 and 27 (57%) were normal. A total of 7 children (21% of those studied) had abnormal audiologic assessments. Three children demonstrated mild high-frequency and 4 moderately severe high-frequency sensorineural hearing loss which was bilateral in 3 and of undetermined laterality in 1. Abnormal neurodevelopmental outcome was significantly associated with cerebral infarction and chronic lung disease. Outcome was not related to demographic or perinatal variables, illness severity prior to extracorporeal membrane oxygenation, or underlying diagnosis. Neurodevelopmental outcome among survivors of extracorporeal membrane oxygenation in this series is consistent with previous reports of morbidity among neonates with severe respiratory failure treated conventionally.

Child

Otitis media in the pediatric intensive care unit: a prospective study.

Otitis media has been previously shown to be a source of sepsis in the pediatric intensive care unit; however, pneumatic otoscopy and other otologic instruments are not commonly used in the pediatric intensive care unit. We undertook a prospective study to determine the prevalence of otitis media, to assess the risk factors involved with the development of these nosocomial infections, and to identify the causative organisms. We conclude that otitis media is a common entity in the pediatric intensive care unit, that it is probably caused by prolonged dysfunction of the eustachian tube associated with oral and nasally-placed tubes and that the bacteriology reflects that of the hospital environment and not that of the community.

Child

Nasal air flow during normal speech production.

Nasal air flow was measured during the speech of 112 normal subjects (59 females and 53 males) ranging in age from three years to 37 years, six months. Flow was zero during nearly all oral consonant and vowel utterances, suggesting that velopharyngeal closure was air-tight. Flow occurred during all nasal consonants and during vowels adjacent to nasal consonants. These effects were interpreted as showing that progressively older subjects and female subjects demonstrate earlier anticipatory coarticulation in preparation for forthcoming nasal consonants.

Adolescent

Urinary N-acetyl-beta-D-glucosaminidase assay in renal transplant recipients.

Urinary N-acetyl-beta-D-glucosaminidase (NAG) activities were measured in 181 patients with renal allografts during a 15-month period. Activities were high immediately after transplantation but decreased rapidly in the absences of complication. Urinary NAG activities increased by 50% or more in relation to 33 of 36 (92%) episodes of acute rejection diagnosed and treated by clinicians during the first 90 days after transplantation. The increase preceded clinical diagnosis in 70% of the cases, the median interval being 1.5 days. NAG activities decreased after treatment of rejection in 90% of the cases. Chronic rejection, renal vein thrombosis, renal artery stenosis, oliguria, hypotension, and the administraion of gentamicin may also cause increased NAG activity. Urinary NAG assay is simple and inexpensive, and is a useful aid to the early diagnosis of rejection of renal transplants. Results must, however, be interpreted by the clinician, bearing in mind other causes for increased activity.

Acetylglucosaminidase

A note on the practical aspects of the assay of N-acetyl-beta-glucosaminidase in human urine.

1. Some practical aspects of the assay of urinary N-acetyl-beta-glucosaminidase activity were studied in patients with renal disease. 2. Centrifugation and dialysis of urine were not necessary prior to assay. 3. When enzyme activity was related to urinary creatinine random urine samples could be used. 4. Since preservatives used to prevent bacterial growth may inhibit enzyme activities, samples should be assayed immediately after collection or stored at 4 degrees C or 20 degrees C. 5. Mild visible haemoglobinuria, eg. derived from lysed red blood cells did not interfere with the enzyme assay.

Acetylglucosaminidase

Renal damage caused by gentamicin: a study of the effects on renal morphology and urinary enzyme excretion.

Gentamicin sulphate was administered to male Wistar rats by intramuscular injection at varying dosage and for varying periods. At high dosage (50-100 mg/kg/day) gentamicin causes tubular necrosis. At dosages equivalent to that given to man (5 mg/kg/day) obvious degenerative changes are produced. Similar changes are seen in human tubular epithelium and urine deposits of patients treated with gentamicin. There is increased excretion of urinary enzymes proportional to the degree of tubular damage. The importance of these changes in man is stressed.

Acetylglucosaminidase

Presence of serum and tissue forms of N-acetyl-beta-glucosaminidase in urine from patients with renal disease.

1. The A, B, I1 and I2 forms of N-acetyl-beta-glucosaminidase present in urine, serum, kidney, liver and cerebral spinal fluid were separated on DEAE-cellulose and their presence confirmed by cellogel electrophoresis. The relative activities of each enzyme were determined by integrating the area under the elution peaks. 2. Serum A-form was eluted at a lower molarity of chloride than liver A-form and this was designated the As-form to distinguish it from the A-form of N-acetyl-beta-glucosaminidase found in liver and kidney. 3. The P-form of N-acetyl-beta-glucosaminidase present in the serum of a group of pregnant women was not detectable in urine samples from the same women. 4. Urinary NAG activities were found to be abnormally high in patients with impaired renal function. 5. The activity of both N-acetyl-beta-glucosaminidases A and B increased in pathological urines. The higher the total N-acetyl-beta-glucosaminidase activity excreted the higher the % of activity of the B-form present. 6. In a number of patients with haematuria an A-form similar to the serum As-form was present in the urine.

Acetylglucosaminidase