[鋅=zinc 可以幫助抵抗感冒的效果，可參看: http://tw.myblog.yahoo.com/jw!GAJfq5CREwTFZ1gGiWhZt.zp/article?mid=8905
這裡第一篇到告說 鋅可以減少小孩肺炎的死亡率，但下一篇報告說，肺炎住院之小孩，服用鋅並不能減短住院時日]
Mortality
Rates Reduced With Zinc in Children With Pneumonia
Clinical Context
According
to the current study by Srinivasan and colleagues, acute respiratory tract
infections are among the most common causes of morbidity and mortality among
children worldwide, especially in developing countries. Also, the prevalence of
zinc deficiency in developing countries is high, estimated at 20% to 69% among
Ugandan children. However, the impact of adding zinc to therapy for pneumonia
on case fatality rates and return to normal respiratory function is not well reported.
This
is a randomized controlled trial conducted in Ugandan children from a single
hospital to examine the effect of adjunct zinc therapy on case fatality rates
and return to normal respiratory function.
Study
Synopsis and Perspective
In a
study conducted in Africa, children aged 6 to 59 months who had severe
pneumonia had reduced mortality when receiving zinc in addition to standard
antibiotics, a new study has found. In addition, the reduction in mortality was
greater among HIV-infected than non-HIV-infected children.
Maheswari
G. Srinivasan, from the Department of Pediatrics and Child Health at the School
of Medicine, Makerere University College of Health Sciences, Kampala, Uganda,
and colleagues reported the findings in an article published online February 8 in BMC Medicine.
"Given
these results, zinc could be considered for use as adjunct therapy for severe
pneumonia, especially among Highly Active Antiretroviral Therapy [HAART] naïve
HIV infected children in our environment," the authors conclude.
According
to the researchers, acute respiratory tract infections is the most common cause
of morbidity and mortality in children younger than 5 years of age, and the
"burden of acute lower respiratory tract infections is 2 to 10 times more
common in developing than in developed countries."
The
results with zinc supplementation in this setting have been mixed. "One
randomized controlled study from Bangladesh showed that zinc adjunct therapy
accelerated recovery of children with severe pneumonia," the authors note,
"but other studies have shown no effect," and "no studies have
assessed the impact of zinc adjunct therapy on case fatality of children with
pneumonia."
To
evaluate this issue, the researchers randomly assigned children aged 6 to 59
months who had severe pneumonia to receive either zinc once daily for 7 days (n
= 176; 20 mg for children aged 12 months or older and 10 mg for younger
children) or a placebo once daily for 7 days (n = 176).
Children
also received standard antibiotics for severe pneumonia and were assessed every
6 hours for oxygen saturation, respiratory rate, and temperature.
Among
the children receiving zinc, 7 (4.0%) died compared with 21 patients (11.9%) in
the placebo group. This represented nearly
a 70% reduction in mortality risk in favor of zinc supplementation
(relative risk [RR] reduction, 0.67; 95% confidence interval [CI], 0.24 -
0.85).
The
greatest risk reduction was seen in HIV-infected children. Among HIV-infected
children, case fatality was 7 of 27 children in the placebo group vs 0 of 28
children in the zinc group (RR, 0.1; 95% CI, 0.0 - 1.0).
In
contrast, in HIV-uninfected children, no difference in case fatality was
observed with zinc vs placebo: case fatality was 7/127 (5.5%) with placebo vs
5/129 (3.9%) among HIV-uninfected children receiving zinc (RR, 0.7; 95% CI, 0.2
- 2.2).
According
to the researchers, the excess risk with placebo was substantially greater
among HIV-positive children than in HIV-negative children (absolute risk
reduction, 26/100 children vs 2/100 children, respectively; P = .006).
They
estimated that 13 patients needed to be treated to avert 1 death, and that children
who received the placebo were 3 times more likely to die compared with those
who received zinc.
"There
are two key findings in this study: overall, zinc supplementation in these
children significantly decreased case fatality, but did not reduce the time to
normalization of the parameters for disease severity," the authors
conclude.
According
to the researchers, zinc supplementation might increase the immune response by
boosting phagocytosis and averting apoptosis of T lymphocytes in HIV-infected
patients.
They
add that zinc deficiency (present in from 20% to 69% of children in this
setting) "compromises immunity through a number of mechanisms, such as T
cell dysfunction and dysregulation of intracellular killing."
The
authors have disclosed no relevant financial relationships.
BMC
Medicine. Published
online February 8, 2012
Study Highlights
- Included were children 6 to 59
months old from a pediatric emergency hospital ward diagnosed with
pneumonia according to criteria from the World Health Organization. - Excluded were children with
known heart conditions, wheezing, heart murmur, or obstructive airway
disease. - Severe pneumonia was defined as
the presence of cough or difficult breathing with tachypnea (rate of ≥ 50
breaths per minute for children 6 - 12 months old and ≥ 40 breaths per
minute for children ages ≥ 12 months). - Oxygen saturation was regarded
as normalized if above 92% in room air for at least 15 minutes, and
respiratory rate was regarded as normal if it was lower than 40 breaths
per minute in children older than 12 months and lower than 50 breaths per
minute in children 6 to 12 months old. - Temperature was regarded as
normal if below 37.5ºC. - The treating team consisted of
3 physicians, 2 nurses, and 2 laboratory personnel. - After diagnosis, children were
randomly assigned to receive either 10 mg (ages ≥ 12 months) or 5 mg (ages
< 12 months) per day of zinc with standard antibiotic therapy for 7
days. - Antibiotic therapy consisted of
intravenous chloramphenicol or ceftriaxone as first-line treatment, or
gentamicin and cloxacillin as second-line treatment. - Zinc supplementation was
administered by a nurse within 30 minutes of administering antibiotics. - Laboratory tests included
malarial parasite blood slide screen, HIV serology studies, and chest
radiography. - Children with oxygen saturation
below 92% were given oxygen by nasal prongs or catheter. - HIV status was determined, and
88.4% of parents consented to testing. - Children were followed up to
hospital discharge, death, or a maximum of 7 days, whichever came first. - They were reviewed every 6
hours for the first 48 hours, then every 12 hours. - Criteria for hospital discharge
included resolution of fever, normal respiratory rate and oxygen
saturation for 48 hours or longer, and disappearance of chest in-drawing. - Of 352 participants, 56.2% were
boys. Mean age was 17.9 months in the zinc group and 18.1 months n the placebo
group. - 176 children were randomly
assigned to zinc and 176 to placebo. - 18.1% of children had low
oxygen saturation (< 92%) at baseline. - Mean respiratory rate was 64.7
breaths per minute. - Of 311 children screened for
HIV status, 17.7% tested positive (17.8% in the zinc and 17.5% in the
placebo group). - Median time to normalization of
respiratory rate was 96 hours in the zinc group and 86 hours in the
placebo group (not significantly different). - Median time to normalization of
temperature was 18.0 hours in both groups. - Median time to normalization of
oxygen saturation was 24 hours in the zinc group and 18 hours in the
placebo group (not significantly different). - Mean duration of
hospitalization was 2.57 days among children who died and 6.91 days for
those who survived. - Overall case fatality rate was
8.0%: 4.0% in the zinc group and 11.9% in the placebo group (RR, 0.33). - The case fatality rate with
zinc supplementation was significantly lower in the 27 HAART-naive,
HIV-positive children (RR, 0.1, fatality of 0/28 [0%] for zinc group vs
7/27 [25.9%] for placebo group). - Among HIV-noninfected children,
the case fatality rate was 3.9% in the zinc group and 5.5% in the placebo
group (RR, 0.7). - The number needed to treat was
13 overall for zinc vs placebo treatment, with excess risk of the placebo
group being 8 per 100 children. - Children who were hypoxic or
malnourished were more likely to die compared with HIV-negative or healthy
children. - Girls had twice the fatality
rate as boys (RR, 2.3). - The authors concluded that
although zinc adjunctive therapy did not reduce the median time to
normalization of respiratory function or temperature in children with
severe pneumonia, it reduced case fatality rates, especially among
children who were HIV positive and HAART naive. - They recommended that zinc be
considered as adjunctive therapy for pneumonia, especially among
HAART-naive, HIV-positive children.
Clinical Implications
- Zinc supplementation in
children with severe pneumonia does not reduce median time to
normalization of temperature, respiratory rate, or oxygen saturation. - Zinc supplementation in
children with severe pneumonia reduces case fatality rates, with a greater
effect on HIV-positive than HIV-negative children.
*****************************
Zinc Does Not Reduce Duration of Severe Pneumonia
March 5, 2012 — In hospitalized children with pneumonia, adjunct treatment with zinc showed only a limited benefit, according to the findings of a new randomized trial conducted in Nepal.
Sudha Basnet, MD, from the Child Health Department, Institute of Medicine, Tribhuvan University, Kathmandu, Nepal, and colleagues report their findings in an article published online March 5 in Pediatrics.
According to the authors, zinc as adjuvant therapy for hospitalized children with pneumonia was beneficial in 1 clinical trial in Bangladesh, but other trials in India and Australia found no effect.
The current study, conducted in Nepal, sought to assess the efficacy of zinc as adjuvant therapy to standard antibiotic treatment in reducing the time to cessation and the risk for treatment failure for a severe pneumonia episode.
The study included 610 children aged 2 to 35 months who presented with severe pneumonia. Children received standard antibiotic treatment and were also randomly assigned to receive zinc (10 mg/day if younger than 12 months and 20 mg/day if older) or placebo daily for up to 14 days.
Although children receiving zinc recovered slightly more quickly than those not receiving zinc, the difference was not statistically significant (hazard ratio, 1.10; 95% confidence interval [CI], 0.94 - 1.30). The median time to cessation of severe pneumonia was identical (49 hours) in both groups, although the range of pneumonia duration was longer in patients receiving placebo.
Likewise, zinc was associated with a marginal but insignificant reduction in the risk for treatment failure (risk ratio, 0.88; 95% CI, 0.71 - 1.10).
More patients receiving the supplement vomited than did those receiving placebo (14% vs 9%; P = .052).
"This study enrolled 610 children and to our knowledge is the largest trial conducted to date on zinc given during severe pneumonia," Dr. Basnet and colleagues conclude.
According to the researchers, only 24% of patients had radiographically confirmed pneumonia, and there was significant beneficial effect of zinc in this subgroup, suggesting that further studies with more specific diagnoses may be needed. The authors did not discuss the prevalence of zinc deficiency in the study population.
The current findings are in contrast to those from another recent study conducted in Africa, and reported by Medscape Medical News, indicating that children aged 6 to 59 months with severe pneumonia had reduced mortality when receiving zinc in addition to standard antibiotics, especially in those infected with HIV.
The study was supported by the European Commission; the Meltzer Foundation in Bergen, Norway; the Danish Council of Developmental Research; and the Research Council of Norway. The authors have disclosed no relevant financial relationships.
Pediatrics. Published online March 5, 2012. Full text
Medscape Medical News © 2012 WebMD, LLC
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