Search PubMed⌕ Search

Biomedical subjects

S L Ward

Publications and source records attributed to S L Ward.

53 records · Page 3Linked to original sources
PubMed1990

Sudden infant death syndrome in infants of substance-abusing mothers.

A population-based study was performed to determine whether substance abuse during the perinatal period may be a risk factor for sudden infant death syndrome (SIDS). The incidence of SIDS was studied in 2143 infants of substance-abusing mothers (ISAM) born in Los Angeles County during 1986 and 1987 who were reported to the Los Angeles County Department of Health Services because of a history of drug exposure or positive urine test results in the mother, infant, or both. By comparing the ISAM birth reports with records of autopsy-proven SIDS in Los Angeles County, we found 19 SIDS cases in the population of 2143 ISAM, a SIDS rate of 8.87 cases per 1000 ISAM (95% confidence interval 5.3 to 13.8). This was significantly higher than the SIDS rate for the non-ISAM general population: 396 SIDS deaths among 325,372 live births, an incidence rate of 1.22 cases per 1000 births, p less than 0.00001. The age of ISAM at death was 99 +/- 63 (mean +/- SD) days compared with 91 +/- 52 days for the non-ISAM population (not significant). The incidence of SIDS was significantly greater in male infants, during the winter months, in black infants, and in non-Hispanic white infants in the non-ISAM population. Such differences were not observed in the ISAM group. A greater incidence of symptomatic apnea was reported before SIDS for the ISAM than for the non-ISAM population (22% vs 5.4%, p = 0.022). We conclude that ISAM have a higher incidence of SIDS than the non-ISAM general population. However, it was not possible to separate maternal substance abuse from other confounding variables that may also have had an impact on SIDS risk in the ISAM group.

Age Factors↗
PubMed1990

Evaluation of epiglottoplasty as treatment for severe laryngomalacia.

Six patients with severe laryngomalacia underwent epiglottoplasty. Four of these patients had life-threatening episodes of airway obstruction before surgery; of these, two had required tracheal intubation and one had required cardiopulmonary resuscitation. Two patients had failure to thrive and two had cor pulmonale. Patients had required a mean of two hospitalizations related to upper airway obstruction. We performed polysomnography during a daytime nap, both before and after epiglottoplasty, in all patients. Respiratory effort, arterial oxygen saturation, and end-tidal carbon dioxide pressure were monitored with continuous electrocardiograms and electrooculograms. All patients had abnormal polysomnograms preoperatively. Six patients had obstructive apnea, four had hypoxemia (arterial oxygen saturation less than 90% while breathing room air), and four had hypoventilation (end-tidal carbon dioxide pressure greater than 45 mm Hg) before epiglottoplasty. Mean age (+/- SEM) at epiglottoplasty was 10.3 +/- 5.3 months. No patients had surgical complications. An endotracheal tube was in place for 25 +/- 7 hours postoperatively, and patients were discharged 4 +/- 1 days postoperatively. Polysomnography performed 2.8 +/- 1.0 months after surgery showed that all patients had improved. Two patients had residual, mild episodes of obstructive apnea, and one patient had mild hypoventilation and desaturation. No patient had further life-threatening events or required further hospitalizations after epiglottoplasty. We conclude that epiglottoplasty is an effective and safe treatment for a selected group of patients with severe laryngomalacia.

Carbon Dioxide↗
PubMed1989

Abnormal control of ventilation in adolescents with myelodysplasia.

Infants with myelomeningocele have abnormalities in ventilatory control. To determine whether these persist into later life, we studied 14 patients with myelomeningocele and Arnold-Chiari malformation (age 18.0 +/- 0.8 (SE) years), and compared them with 14 control subjects (age 24.0 +/- 0.9 years). Pulmonary function and ventilatory muscle strength did not differ between patients with myelomeningocele and control subjects. Hypercapnic ventilatory responses were significantly lower in the group with myelomeningocele (1.98 L/min/mm Hg) compared with control values (3.33 L/min/mm Hg; p less than 0.01). Hypoxic ventilatory responses (-1.4 L/min/%oxygen saturation of hemoglobin in arterial blood) were not significantly different from control values (-2.14 L/min/%oxygen saturation). In control subjects the hypercapnic and hypoxic ventilatory responses were highly correlated with each other within subjects (r = 0.84; p less than 0.002) but not in those with myelomeningocele (r = 0.34; not significant). We concluded that adolescents and young adults with myelomeningocele have abnormalities in control of ventilation during sleep and wakefulness. We speculate that the Arnold-Chiari malformation interferes with central chemosensitivity (hypercapnic ventilatory response) and central integration of chemoreceptor output.

Adolescent↗
PubMed1989

A retrospective survey of anaesthesia in horses with colic.

The purpose of this survey was to identify complications occurring in horses with colic during anaesthesia and recovery from anaesthesia; and to determine any relationships between these complications and drugs used for induction or maintenance of anaesthesia. Two hundred and thirty nine horses were anaesthetised on a total of 250 occasions for colic surgery between January 1985 and May 1987. Of these, 189 recovered from 200 anaesthetic episodes. Most horses received xylazine and guaifenesin with either thiobarbiturate (68 per cent) or ketamine (24 per cent) and anaesthesia was maintained with either halothane (51 per cent), isoflurane (43 per cent), or first halothane then isoflurane (6 per cent). Sixty nine per cent also received an opioid. Hypotension or tachycardia were recorded in 15 and 13 per cent of anaesthesias, respectively. Arterial PO2 was less than 13.3 kPa in 17 per cent of 175 anaesthesias. None of these complications was associated with a specific anaesthetic agent. Hypertension was recorded in 11.5 per cent of anaesthesias and occurred more frequently during isoflurane anaesthesia (P < 0.05). The mean duration of anaesthesia was 126 mins (range, 50-270 mins), and was not different for horses receiving thiobarbiturate or ketamine, halothane or isoflurane. The time taken to stand after anaesthesia recorded on 149 occasions and was 63 +/- 24 mins (range, 15-135 mins). This was not different for the different anaesthetic agents. Horses that were excited or had difficulty standing up during recovery had a significantly longer duration of anaesthesia (165 +/- 51 mins) (P < 0.05) but no specific anaesthetic agent was involved. Of the 189 horses, 148 (75 per cent) survived and were discharged from the hospital. Horses that did not survive had a significantly increased prevalence of anaesthetic complications, and longer durations of anaesthesia.

Administration, Inhalation↗
PubMed1987

Immunochemical and kinetic evidence for two different prostaglandin H-prostaglandin E isomerases in sheep vesicular gland microsomes.

Splenic lymphocytes from mice immunized with a partially purified prostaglandin (PG) H-PGE isomerase from sheep vesicular glands were fused with SP2/0-Ag14 myeloma cells. Two spleen cell-myeloma hybrids (hei-7 and hei-26) were selected and cloned. The mouse antibodies secreted by the two hybrids, IgG1 (hei-7) and IgG1 (hei-26), caused immunoprecipitation of a maximum of 45 and 22%, respectively, of the solubilized PGH-PGE isomerase activity of sheep vesicular gland; immunoprecipitation of activity by the two antibodies was additive. The antigens reactive with IgG1 (hei-7) and IgG1 (hei-26) were identified as proteins with Mr = 17,500 and 180,000, respectively, by Western transfer blotting or sodium dodecyl sulfate-polyacrylamide gel electrophoresis of immunoprecipitated 125I-labeled microsomes. The PGH-PGE isomerase activities precipitated by IgG1 (hei-7) and IgG1 (hei-26) exhibited different kinetic properties with respect to time course, Km for PGH2, and concentration dependence for GSH. No significant GSH-S-transferase activity was present in these immunoprecipitates. These data indicate that there are at least two different proteins in sheep vesicular gland microsomes capable of catalyzing GSH-dependent PGH-PGE isomerase reactions. IgG1 (hei-7), but not IgG1 (hei-26), caused coprecipitation of PGH synthase and PGH-PGE isomerase activities when incubated with intact right-side-out vesicular gland microsomes. Thus, the epitope for IgG1 (hei-7) is located on the cytoplasmic surface of those microsomal spheres which contain PGH synthase. This latter finding suggests that the isomerase reactive with IgG1 (hei-7) is involved in PGE synthesis in sheep vesicular glands.

Animals↗
PubMed1986

Abnormal sleeping ventilatory pattern in infants of substance-abusing mothers.

Infants born to opiate-abusing mothers have a decreased ventilatory response to carbon dioxide and a five to ten times increased risk of sudden infant death syndrome (SIDS). These abnormalities of ventilatory control may be associated with abnormal sleeping ventilatory patterns. Therefore, 28 overnight pneumograms (respiratory pattern recording and electrocardiogram) were obtained from 27 infants of substance-abusing mothers (ISAM) (five opiate, seven phencyclidine hydrochloride, three cocaine, and 12 polydrug abusers) and compared with pneumograms from 43 control infants. Pneumograms were quantitated for total sleep time, greatest duration of apnea, total duration of apnea greater than or equal to 6 s, periodic breathing, and mean heart and respiratory rates. The ISAM had a longer total sleep time, greater durations of apnea, a higher total duration of apneas greater than or equal to 6 s, more periodic breathing, a higher mean respiratory rate, and a lower mean heart rate. Thirty-two percent of pneumograms from ISAM were abnormal compared with 9.3% of the control pneumograms. We conclude that ISAM have abnormal sleeping ventilatory patterns that may be related to their increased SIDS risk.

Age Factors↗
PubMed1986

Abnormal ventilatory patterns during sleep in infants with myelomeningocele.

Some infants with myelomeningocele, hydrocephalus, and Arnold-Chiari malformation have symptomatic apnea or hypoventilation. The incidence of abnormalities of the ventilatory pattern during sleep in asymptomatic infants with myelomeningocele is not known. Therefore we performed overnight pneumograms (recordings of ventilatory pattern and electrocardiogram) in 18 asymptomatic infants with myelomeningocele and compared them with pneumograms from 64 control infants. Infants with myelomeningocele had longer total sleep time (596 +/- 16 minutes vs 536 +/- 10 minutes, P less than 0.005), longer episodes of longest apnea (12.6 +/- 0.8 seconds vs 8.1 +/- 0.3 seconds, P less than 0.001), greater total duration of apnea greater than or equal to 6 seconds as percent total sleep time (1.02% +/- 0.18% vs 0.23% +/- 0.03%, P less than 0.001), and lower mean heart rates (120 +/- 5 vs 145 +/- 5, P less than 0.001) than did control infants. No abnormal bradycardia was observed in either group. Thirteen (72%) of 18 infants with myelomeningocele had abnormal pneumograms, compared with 4 (6%) of 64 control infants (P less than 0.0005). We conclude that asymptomatic infants with myelomeningocele have a high incidence of ventilatory pattern abnormalities during sleep.

Apnea↗
PubMed1986

Absent hypoxic and hypercapneic arousal responses in children with myelomeningocele and apnea.

Hypoxic and hypercapneic arousal responses from quiet sleep were tested in seven infants with myelomeningocele and Arnold-Chiari malformation who were symptomatic with apnea and/or hypoventilation. All infants with myelomeningocele required tracheostomy and posterior fossa decompression. Responses were compared with those of nine healthy control infants. To assess hypoxic arousal, inspired PO2 was decreased until the end-tidal (alveolar) PO2 reached 45 mm Hg for a maximum of three minutes. Eleven studies were performed in seven infants with myelomeningocele, and arousal occurred in only two studies (18.2%). Eight of nine control infants aroused to hypoxia (89%). To test hypercapneic arousal, inspired PCO2 was increased until end-tidal PCO2 reached 60 mm Hg for a maximum of three minutes. Eight studies were performed on six infants with myelomeningocele, and arousal occurred in three studies (37.5%). All seven control infants studied aroused to hypercapnea (100%). Three infants with myelomeningocele subsequently died. Infants with myelomeningocele, Arnold-Chiari malformation, and apnea or hypoventilation have arousal deficits to respiratory stimuli.

Arnold-Chiari Malformation↗
PubMed1986

Sudden infant death syndrome in infants evaluated by apnea programs in California.

Home apnea/bradycardia monitoring is frequently used in the management of infants at increased risk for sudden infant death syndrome (SIDS). However, some infants have died despite evaluation by infant apnea programs, and the benefits of home monitoring remain unproven. To determine the SIDS rate and risk factors of infants evaluated by infant apnea programs, 31 apnea programs and ten home monitor vendors in California were surveyed. Eleven (35%) of the apnea programs and four (40%) of the vendors responded. Information was obtained on 26 infants who died. Thirteen (50%) deaths were due to SIDS. Abnormal sleep studies did not predict death. Fifteen infants died despite a recommendation for home monitoring. Seven deaths occurred in association with technical errors or noncompliance with monitoring. Four deaths were due to nonaccidental trauma. The apnea programs evaluated 3,406 infants during a 5-year period; 1,841 had monitoring recommended. Term infants with apnea, subsequent siblings of SIDS victims, and infants evaluated at referral centers were more likely to have monitoring recommended than premature infants with apnea or infants evaluated at nonreferral centers (P less than .0001). Infants who had monitoring recommended were at equal risk of dying of SIDS as those who did not.

California↗
PubMed1985

Ventilatory pattern following diphtheria-tetanus-pertussis immunization in infants at risk for sudden infant death syndrome.

To evaluate the effects of diphtheria-tetanus-pertussis (DTP) immunization on the ventilatory pattern during sleep in infants at increased risk for sudden infant death syndrome (SIDS), we performed overnight pneumograms (recordings of ventilatory pattern and electrocardiogram) on 30 control infants, 46 infants with unexplained apnea, and 33 subsequent siblings of SIDS victims the night before and the night following a DTP immunization. Pneumograms were quantitated for total sleep time, longest apnea (in seconds), total duration of apneas longer than 6 s (in minutes), and total periodic breathing (in minutes). Following the DTP immunization there was no significant change in any criterion quantitated on pneumograms from any group except for a decrease in periodic breathing in the unexplained apnea group. We conclude that DTP immunization does not increase abnormalities of the ventilatory pattern as recorded by the pneumogram technique in infants at increased risk for SIDS.

Diphtheria Toxoid↗
PubMed1980

Rhesus brain gas tension and learned task performance responses to normoxic and hyperoxic breathing.

The impact of extended exposure to 21 and 100% O2 breathing mixtures on brain tissue oxygenation and performance of a learned task was studied in seven rhesus monkeys. Trained in the Sidman Avoidance Task, the animals were exposed to either breathing mixture for a period of 3.5 h in which brain tissue PO2, PCO2, and PN2 were observed. With 100% O2, PO2 and PCO2 rose significantly (less than 0.01 and less than 0.05, respectively) above control levels while PN2 fell significantly (less than 0.01) below its baseline value. With 100% O2 no statistically significant difference in gas tension values was shown for performance vs. nonperformance conditions. There was no difference in the number of shocks received with either breathing mixture. Lever press response frequency decreased throughout the experiment for both groups. During the last performance session, response frequency for the 100% O2 group leveled off, whereas for the 21% O2 group it continued to decrease.

Animals↗
PubMed1979

Determination of cerebral and neck subcutaneous tissue PO2 with 3 and 4 +Gz in M. mulatta.

Four male and four female, fully conscious, M. mulatta were exposed twice each to diphasic accelerations of 3 or 4 +Gz (3 min) with a 10-min, 1-G intersession. One polarographic electrode was inserted intracortically and another one into neck subcutaneous tissue. With the first of two 3 or 4 +Gz exposures, cerebral PO2 fell from 15.11 to 5.73 and 2.92 torr, respectively; subcutaneous PO2 fell from 27.6 to 7.72 and 4.8 torr, respectively. Cerebral tissue exhibits post-G hyperoxia, related to initial stress intensity; even after the 10-min intersession, it is capable of mitigating the O2 desaturation effect of the second stress. Cerebral and subcutaneous tissue oxygen desaturation with G onset are comparable, but re-oxygenation in the latter tissue is apparently inertia-ridden and a simple relationship between the overall responses of cerebral and subcutaneous PO2 to +Gz acceleration could not be demonstrated.

Animals↗
PubMed1978

Effects of increased ambient CO2 on brain tissue oxygenation and performance in the hypoxic rhesus.

Alterations of cerebral gas tensions and performance in response to hypoxia, with or without 5% CO2 in the ambient inspirate, were studied in eight conscious rhesus monkeys. The animals were trained to perform a lever press (Sidman) avoidance task. Physiological and performance data were obtained during exposures to normal (21% O2) and hypoxic (12, 10, and 8% O2--all with N2 balance) breathing atmospheres, with or without the addition of 5% CO2. With hypoxia, cerebral PO2 and PCO2 declined steadily, but a significant performance decrement was noted only at the 8% O2 level. With the addition of 5% CO2 to the inspired atmospheres, cerebral PO2 was elevated relatively but still declined as hypoxia intensified. Cerebral PCO2 and the avoidance task performance were sustained at near baseline values with the 5% CO2 inspirate.

Animals↗
PubMedDate not supplied

Factors associated with the transition to nonprone sleep positions of infants in the United States: the National Infant Sleep Position Study.

CONTEXT: Studies have demonstrated strong associations between the prone sleep position (on the stomach) and sudden infant death syndrome (SIDS). In 1992, the American Academy of Pediatrics recommended that infants be placed to sleep laterally (on their side) or supine (on their back) to reduce SIDS risk, and in 1994, the national public education campaign "Back to Sleep" was launched. OBJECTIVE: To determine the typical sleep position of infants younger than 8 months in the United States, the changes that occurred after these recommendations, and the factors associated with the placement of infants prone or supine. DESIGN: Annual nationally representative telephone surveys. SETTING: The 48 contiguous states of the United States. PARTICIPANTS: Nighttime caregivers of infants born within the last 7 months between 1992 and 1996. Approximately 1000 interviews were conducted per year. MAIN OUTCOME MEASURES: The position the infant was usually placed in for sleep, and the position the infant was most commonly found in when checked during the night's sleep. RESULTS: Ninety-seven percent of respondents in each wave of the survey usually placed their infant to sleep in a specific position. Infants were placed in the prone position by 70% of caregivers in 1992, prior to the campaign, but only 24% in 1996. Supine and lateral placements increased during this time period, from 13% in 1992 to 35% in 1996 and from 15% in 1992 to 39% in 1996, respectively. Significant predictors of prone placement included maternal race reported as black (odds ratio [OR], 2.34; 95% confidence interval [CI], 1.68-3.26), mother's age 20 to 29 years (OR, 1.28; 95% CI, 1.09-1.50), region reported as the mid-Atlantic (OR, 1.41; 95% CI, 1.12-1.78) or southern states (OR, 1.47; 95% CI, 1.22-1.70), mothers with a previous child (OR, 1.68; 95% CI, 1.43-1.97), and infants younger than 8 weeks (OR, 0.63; 95% CI, 0.46-0.85). Infants aged 8 to 15 weeks were significantly more likely to be placed nonprone over time compared with the other age groups. Most of the risk factors for prone were significantly related in the opposite direction to supine placement. CONCLUSIONS: The prevalence of infants placed in the prone sleep position declined by 66% between 1992 and 1996. Although causality cannot be proved, SIDS rates declined approximately 38% during this period. To achieve further reduction in prone sleeping, efforts to promote the supine sleep position should be aimed at groups at high risk for prone placement.

Guidelines as Topic↗
PubMedDate not supplied

A comparison of pneumogram recordings in infants in the hospital and at home.

It is not known how environment affects the ventilatory pattern of infants during sleep. Pneumogram recordings of ventilatory pattern and electrocardiograms are performed both in the hospital and at home. However, it is not known if the data obtained in these two settings are comparable. Therefore, 12-hour overnight PNGs were recorded in the hospital and at home within 10 days on 64 infants in three diagnostic categories: apnea of infancy, apnea of prematurity, and siblings of victims of sudden infant death syndrome. Pneumograms were quantitated for total sleep time (TST in minutes), longest apnea (in seconds), periodic breathing, and the total duration of apneas lasting 6 seconds or longer. TST was longer at home for the total group (p less than 0.001) and for the apnea of infancy group (p less than 0.005). No other differences were found between hospital and home recordings for any parameter. There was no difference in the number of abnormal pneumograms recorded in the hospital and at home. Therefore, hospital and home pneumogram recordings are equally sensitive and accurate.

Electrocardiography↗
PubMedDate not supplied

Caring and healing in the 21st century.

As the 21st century approaches, nurses must be prepared to offer new treatment methods when caring for children. The purpose of this article is to familiarize nurses with human caring theory and complementary and alternative medicine, and to offer a practical way of integrating these methods into nursing care. Nurses can learn to choose simple, conservative, noninvasive, nonintrusive healing methods that are met with little resistance by other health care professionals. Clinical implications of the Nurse's Tool Box suggest methods such as drawing, acupressure, guided imagery, storytelling, therapeutic touch, soft music, and humor as ways to help children heal. By tapping into certain frequency currents through the use of these tools, nurses may build, repattern, or facilitate human energies to replenish children's minds, bodies, and souls, creating wholeness and harmony. By understanding human caring theory and complementary and alternative medicine, and by using a practical approach to healing, nurses in the new century can mend children in ways they never have before.

Complementary Therapies↗