Human rhinovirus infections of the lower respiratory tract in hematopoietic stem cell transplant recipients

BACKGROUND

Human rhinoviruses (HRVs) are a common cause of upper respiratory infection (URI) in hematopoietic stem cell transplant (HSCT) recipients; yet, their role in lower respiratory illness is not well understood.

METHODS

We performed a retrospective chart review of HSCT recipients with HRV infection from the time molecular detection methods were implemented at our institution in 2008. Factors associated with proven or possible HRV pneumonia at the first HRV detection were evaluated by univariate and multivariate analysis. We then characterized all episodes of proven and possible HRV pneumonia from the initial HRV infection through a 1-year follow-up period.

RESULTS

Between 2008 and 2011, 63 HSCT recipients had ≥1 documented HRV infections. At first HRV detection, 36 (57%) patients had HRV URI and 27 (43%) had proven or possible HRV pneumonia; in multivariate analysis, hypoalbuminemia (odds ratio [OR] 9.5, 95% confidence interval [CI] 1.3-71.7; P = 0.03) and isolation of respiratory co-pathogen(s) (OR 24.2, 95% CI 2.0-288.4; P = 0.01) were independently associated with pneumonia. During the study period, 22 patients had 25 episodes of proven HRV pneumonia. Fever (60%), cough (92%), sputum production (61%), and dyspnea (60%) were common symptoms. Fifteen (60%) episodes demonstrated bacterial (n = 7), fungal (n = 5), or viral (n = 3) co-infection. Among the remaining 10 (40%) cases of HRV monoinfection, patients' oxygen saturations ranged from 80% to 97% on ambient air, and computed tomography scans showed peribronchiolar, patchy, ground glass infiltrates.

CONCLUSIONS

HRV pneumonia is relatively common after HSCT and frequently accompanied by bacterial co-infection. As use of molecular assays for respiratory viral diagnosis becomes widespread, HRV will be increasingly recognized as a significant cause of pneumonia in immunocompromised hosts.

Outcomes following prolonged preterm premature rupture of the membranes

OBJECTIVE

Rupture of the membranes in the second trimester is reported to be associated with high rates of pregnancy loss, neonatal mortality and morbidity. This article describes the outcomes of liveborn infants delivered following a prolonged period of membrane rupture occurring before 24 weeks' gestation.

PATIENTS AND SETTING

Over a 5-year period, consecutive pregnancies complicated by spontaneous rupture of the membranes before 24 weeks' gestation were identified. Evaluation of short-term outcomes before discharge of liveborn infants delivered, in a tertiary referral centre, following prolonged rupture of membranes of duration greater than 2 weeks.

RESULTS

Of 98 pregnancies identified with rupture of the membranes before 24 weeks' gestation, 40 (41%) women progressed to deliver a liveborn infant following a latent period of at least 14 days. Although most liveborn infants required neonatal intensive care including mechanical ventilation (n = 38; 78%), the survival rate to hospital discharge was 70% (n = 28). Airleak occurred in 7 (25%) survivors and 8 (67%) deaths. Among the survivors, 12 (43%) required supplemental oxygen at 36 weeks' postmenstrual age and no infant had grade 3 or 4 intraventricular haemorrhage. One infant had a postmortem diagnosis of pulmonary hypoplasia and nine others had clinical features consistent with this diagnosis. Low liquor volume was not uniformly associated with a poor outcome.

CONCLUSION

With full contemporary neonatal intensive care, the outcome for liveborn infants in the present cohort delivered following membrane rupture occurring before 24 weeks' gestation, of at least 14 days duration, was better than previously reported.

Newer approaches to the diagnosis of early onset neonatal sepsis

Accurate and timely diagnosis of early onset neonatal sepsis remains challenging to the clinician and the laboratory. A test with a rapid turnaround time with 100% sensitivity, rather than high specificity, which allows accurate diagnosis and appropriate antimicrobial treatment or which allows antibiotics to be safely withheld in non-infected infants, is desirable. Many potential markers (acute phase reactants, cell surface markers, cytokines) are not routinely available to the laboratory, and most likely combinations of markers will ensure greater diagnostic accuracy. In the future, molecular biology techniques offer the prospect of rapid identification of both pathogens and antimicrobial resistance markers.

Inhaled nitric oxide for acute hypoxemic respiratory failure in children and adults

BACKGROUND

Acute hypoxemic respiratory failure affects all age groups and may result from a number of systemic diseases. It continues to be associated with high mortality and morbidity. Initial studies examining the effect of inhaled nitric oxide in respiratory failure demonstrated transient improvement in oxygenation but did not examine mortality or other significant morbidity outcomes.

OBJECTIVES

To systematically examine randomized controlled trials addressing the effect of inhaled nitric oxide, compared with placebo inhaled gas, on mortality and morbidity in patients with acute hypoxemic respiratory failure.

SEARCH STRATEGY

Randomized controlled trials were identified from electronic databases: The Cochrane Central Register of Controlled Trials (CENTRAL) (Issue 2, 2002;MEDLINE (January 1966-August 2002); EMBASE (1980-March 2001); CINAHL (1982-July 2002), as well as from bibliographies of retrieved articles. Relevant journals and conference proceedings were hand searched and authors published in this field were contacted for knowledge of unpublished ongoing trials.

SELECTION CRITERIA

Randomized controlled trials comparing inhaled nitric oxide with maximal conventional therapy and inhaled placebo, in either children or adults with acute hypoxemic respiratory failure.

DATA COLLECTION AND ANALYSIS

Qualitative assessment of each trial was made and analyses performed according to statistical methods in Review Manager MetaView 4.1. A sub-group analysis was performed to assess the impact of inhaled nitric oxide at varied doses.

MAIN RESULTS

Five randomized controlled trials were evaluated, assessing 535 patients with acute hypoxemic respiratory failure (Age range not provided). Lack of data prevented assessment of all outcomes. There was no significant difference of nitric oxide on mortality in trials without cross-over (RR 0.98, 95%CI 0.66,1.44). Published evidence from one study demonstrated nitric oxide to transiently improve oxygenation in the first 72 hours of treatment. Limited data demonstrated no significant difference in ventilator-free days between treatment and placebo groups, and no specific dose of nitric oxide was significantly advantageous over another. Other clinical indicators of effectiveness, such as duration of hospital and intensive care stay, were inconsistently reported. There were no significant complications directly attributable to this treatment.

REVIEWER'S CONCLUSIONS

Nitric oxide did not demonstrate any statistically significant effect on mortality and transiently improved oxygenation in patients with hypoxemic respiratory failure. Lack of data prevented assessment of other clinically relevant end points. If further trials comparing inhaled nitric oxide with an inhaled placebo are to proceed, they should be stratified for primary disease, assess the impact of other combined treatment modalities for respiratory failure, and must specifically evaluate clinically relevant outcomes, before any benefit of inhaled nitric oxide for respiratory failure can be excluded.

Outcome of infants 23-26 weeks' gestation pre and post surfactant

To describe mortality and neurodevelopmental outcome before and after the introduction of rescue therapy with natural surfactant in two neonatal units in Toronto, Canada, a retrospective cohort study of 891 liveborn 23-26 wk gestational age infants, 421 presurfactant (1982-1987) and 470 postsurfactant (1990-1994) was performed. Overall mortality was stable over time (41% vs 35%, p = 0.077), but declined for inborn 24 (71% vs 43%, p = 0.03) and 26 wk (26% vs 13%, p = 0.01) gestational age infants and was higher in surfactant-treated infants (p < 0.0001). Chronic lung disease (61% vs 34%, p < 0.0001) and bilateral blindness (8% vs 4%, p = 0.004) declined over time, with stable rates of cerebral palsy (12% vs 15%), cognitive deficit (27% vs 26%) and aided sensorineural hearing loss (5% vs 4%). Sixty-five percent of surviving infants in both eras were free from neurodevelopmental impairment, and severe impairment declined over time (p = 0.035). This study shows no secular change in overall mortality in a large cohort of 23-26 wk gestational age infants since the introduction of rescue therapy with natural surfactant. However, it does suggest that maternal transfer to and delivery of all extremely preterm infants in high risk perinatal centres is justified.

Systemic Candida infection in extremely low birth weight infants: short term morbidity and long term neurodevelopmental outcome

OBJECTIVE

To describe mortality, morbidity at discharge and neurodevelopmental outcome at 2 years corrected age in extremely low birth weight infants with systemic Candida infection during intensive care stay.

METHOD

We identified all extremely low birth weight (birth weight <1000 g) infants diagnosed with Candida sepsis and/or meningoencephalitis between 1988 and mid-1996 in the tertiary neonatal intensive care centers of Toronto. The outcome of the infected infants at discharge and at 2 years corrected age was compared with a cohort of 470 extremely low birth weight infants born between 1990 and 1994.

RESULTS

Forty-six extremely low birth weight infants with systemic Candida infection, mean (+/-SD) gestational age of 24.7 +/- 1.6 weeks and birth weight 699 +/- 135 g, were identified. Case fatality rate was 37% (17 of 46), not significantly different from the control group (35%). Data on 27 infected survivors were available at discharge. All had chronic lung disease compared with 33% in the control cases (P = 0.0001), a high incidence of periventricular leukomalacia (26% vs. 12%, P = 0.06) and an increase in severe retinopathy of prematurity (22% vs. 9%, P = 0.04); 60% had adverse neurologic outcomes at 2 years corrected age compared with 35% in the control group, and 41% vs. 12% had severe disabilities (P = 0.005). Cranial ultrasound examination was the only diagnostic modality in 5 of 13 (38%) cases with central nervous system Candida involvement. All infants with brain parenchymal lesions detected by cranial ultrasound had poor outcome. Early diagnosis and commencement of antifungal treatment favorably affected the outcome.

CONCLUSIONS

Systemic Candida infection is associated with increased short and long term morbidity in extremely low birth weight infants. Candida infection of the central nervous system has a significant impact on long term neurodevelopmental outcome. Performance of cranial ultrasound examination is recommended as a part of the diagnostic investigation in these infants. Detection of brain parenchymal involvement might provide further information to predict outcome.

The impact of basal forebrain lesions on the ability of rats to perform a sensory discrimination task involving barrel cortex

Depletion of cortical acetylcholine (ACh) correlates with reduced stimulus-evoked 2-deoxyglucose (2-DG) uptake in rodent somatosensory cortex. We examined the effect of unilateral basal forebrain lesions and subsequent cortical ACh depletion on (1) the ability of rats to detect a passively applied deflection of the whiskers, and (2) whisker-evoked 2-DG uptake. Normal adult rats were trained on a T-maze to respond by turning in one direction if the whiskers were displaced and in the opposite direction on presentation of a sham stimulus; only the left set of whiskers was stimulated. When the animal performed at the 80% correct level for three consecutive sessions (criterion), it was randomly assigned to a group receiving either a saline injection (sham lesion) or an ibotenic acid injection (excitotoxic lesion) into the right basal forebrain. Behavioral testing continued until the animal returned to the prelesion criterion, at which time a terminal 2-DG experiment was conducted. None of the sham-lesioned rats experienced disruption of their ability to perform the task. All excitotoxic basal forebrain-lesioned rats were impaired in task performance, but eventually returned to prelesion performance levels. The length of time required to return to criterion was positively correlated with the amount of cortical ACh depletion. Despite the behavioral recovery of the ACh-depleted rats, 2-DG uptake in response to whisker stimulation continued to be reduced in the somatosensory cortex ipsilateral to the basal forebrain lesion. These findings suggest that ACh depletion, which results in a long-lasting decrease in neuronal responses to evoked stimuli, transiently impairs an animal's ability to perceive and appropriately respond to sensory information; the duration of impairment is related to the degree of depletion.

Cholinergic basal forebrain transplants restore diminished metabolic activity in the somatosensory cortex of rats with acetylcholine depletion

It has been known for several years that stimulus-evoked metabolic activity is reduced in the somatosensory cortex of animals with basal forebrain lesions that deplete the neocortex of acetylcholine (ACh). During 2-deoxyglucose (2-DG) experiments, animals with unilateral basal forebrain lesions demonstrate a decreased response to somatic stimulation, while background metabolic activity in the surrounding cortical regions remains normal. In an attempt to ameliorate these deficits, we examined the ability of embryonic cholinergic basal forebrain transplants inserted into neocortex to innervate surrounding cortical regions and restore functional 2-DG activity in adult host rats previously depleted of ACh by basal forebrain lesions. To accomplish this goal, a series of experiments were conducted in which we (1) depleted the cerebral cortex of ACh by injecting an excitotoxin into the rat basal forebrain, (2) transplanted embryonic basal forebrain or embryonic neocortical (control) tissue into the ACh-depleted cortex and, (3) 6-12 months later, used the 2-DG metabolic mapping technique to examine effects of the transplants on metabolic activity evoked by whisker stimulation in rat somatosensory (barrel) cortex. Histochemical analysis revealed that acetylcholinesterase (AChE) staining within 2 mm of the basal forebrain transplants was similar in density to the contralateral normal hemisphere. AChE staining farther than 2 mm from the basal forebrain transplants and throughout hemispheres containing neocortical (control) transplants was greatly reduced, with few AChE-positive fibers present, a finding typical of cerebral cortex in basal forebrain-lesioned animals. Stimulus-evoked 2-DG uptake in barrels adjacent to the basal forebrain transplants, and therefore within AChE-rich territory, was similar to that in corresponding barrels identically activated in the contralateral hemisphere. 2-DG activity was reduced, however, in stimulated barrels outside the region of dense AChE-positive staining, as well as in all activated barrels in hemispheres containing control transplants of embryonic neocortex. These results indicate that transplantation of cell suspensions containing embryonic cholinergic basal forebrain, but not neocortex, can ameliorate basal forebrain lesion-induced deficits in functional activity, and that the restoration of activity is influenced by proximity to the transplant.

Basal forebrain lesions alter stimulus-evoked metabolic activity in rat somatosensory cortex

Acetylcholine (ACh) has been suggested to play a crucial role in normal cortical functioning. To assess the impact of cortical ACh depletion on metabolic activity in the barrel field of rat somatosensory cortex, unilateral lesions of the basal forebrain were made. One to 9 weeks later, a 2-deoxyglucose experiment was conducted. Stimulus-evoked metabolic activity in the barrel field ipsilateral to the lesion was significantly reduced compared with the contralateral side. These results suggest that ACh plays a significant role in processing stimulus-evoked sensory information.

Time course and decay of effects of near work on tonic accommodation and tonic vergence

Changes in tonic accommodation and tonic vergence were monitored before, during and immediately after a 45 min period of reading adult level text displayed on either a computer monitor or hard copy at 20 cm under binocular viewing conditions. Both tonic accommodation and tonic vergence gradually increased during the reading period, with changes in tonic accommodation occurring more rapidly. The average increases in tonic accommodation and tonic vergence following reading were 0.35 dioptres and 0.38 metre angles, respectively. Decay of both tonic components to the baseline in either light or total darkness occurred within the first 3 min. These results suggest that a moderate period of interrupted reading at a close distance can produce a transient increase in the tonic oculomotor levels.

The trustee's guide to vendors of hospital information systems

Hospital information systems (HISs) vary in their breadth of application, in the depth of support their vendors will provide, and in their costs and benefits. Included here in clear, succinct tables is a guide to the leading HIS vendors that highlights some of these differences.

Information systems: the status of level 1

A survey of vendors reveals the growing range of applications that are offered by second-generation hospital information systems.

"Our babies shall not die": a community's response to medical neglect

The free neighborhood health center in a Midwest U.S. town was developed in response to a report that indicated that infant mortality rates were higher for the Black community than for the community-at-large. The health center soon took on the full range of health problems brought by clients regardless of client's race, ethnicity, or income. The processes for managing health care problems in an environment where racism was the rule rather than the exception are considered in this study.