We identified 50 controlled trials. Of these, we excluded 35 trials and 10 trials are awaiting for classification due to difficultly in retrieving the article or contacting the original trial authors. These data will be analysed when we update the review. The remaining six trials involving 437 participants met the inclusion criteria and were included in this review.
Results of the search
125 relevant studies appeared in our search.
Participants in the included studies were of any age or sex with pneumonia. Two trials (Cao 2007; van Woensel 2003) mainly focused on children, while the other four (Confalonieri 2005; Marik 1993; McHardy 1972; Mikami 2007) focused on adults or the elderly.
One study was conducted in China (Cao 2007) with 120 children aged from three months to 14 years infected by M. pneumoniae. They were divided into four groups: 30 in the control group, 30 in the budesonide (Pulmicort) group, 30 in the clarityne (Loratadine tablets) group, and 30 in the thymosin or transfer factor (TF) injection group.
The Confalonieri 2005 study involved 48 participants: 24 in the hydrocortisone infusion group and 24 in the placebo group.
There were 30 patients in the Marik 1993 study: 14 in the hydrocortisone group and 16 in the placebo group.
One hundred and twenty six participants were included in McHardy 1972 and were divided to four groups: 43 in group 1, 20 in group 2, 43 in group 3 and 20 in group 4.
The Mikami 2007 study involved 31 patients: 15 received prednisolone intravenously for three days and 16 in the control group did not receive prednisolone.
There were 82 participants in the van Woensel 2003 study: 37 in the steroid group (including 18 participants with bronchiolitis and 17 with pneumonia) and 45 in the control group (including 21 participants with bronchiolitis and 22 with pneumonia).
In all trials, the interventions were antibiotics with corticosteroids versus antibiotics with placebo or antibiotics alone. The corticosteroids included hydrocortisone (Confalonieri 2005; Marik 1993), prednisolone (McHardy 1972; Mikami 2007), budesonide (Cao 2007) and dexamethasone (van Woensel 2003). In Confalonieri 2005, hydrocortisone was given as an intravenous 200 mg loading bolus followed by an infusion (hydrocortisone 240 mg in 500 cc 0.9% saline) at a rate of 10 mg/hour for seven days and protocol-guided antibiotic treatment.
In Marik 1993, the participants of the treatment group received 10 mg/kg of hydrocortisone intravenously 30 minutes prior to starting antibiotic therapy.
In McHardy 1972, group 1 and group 3 received 1 g ampicillin daily and 2 g ampicillin daily, respectively; group 2 received 1 g ampicillin plus 20 mg prednisolone and group 4 received 2 g ampicillin plus 20 mg prednisolone, respectively. In Mikami 2007, the corticosteroids group received 40 mg of prednisolone intravenously for three days plus intravenous antibiotics within eight hours of hospital admission. This was then modified, based on culture results.
In some of the studies, treatment of pneumonia with corticosteroids was just one part of the trial. In the study by Cao 2007 for example, the control group were given azithromycin or erythromycin for seven days, and in the budesonide (Pulmicort) group the participants also had budesonide (Pulmicort) inhalation 250 to 500 g/day for seven days in the control group. The study aimed to compare the effectiveness of budesonide and azithromycin and erythromycin for M. pneumonia in children. We only focused on the results of the effectiveness of budesonide.
The van Woensel 2003 study looked at the effectiveness of corticosteroids for pneumonia and bronchiolitis. The trial medication was intravenous dexamethasone (0.15 mg/kg six-hourly for 48 hours) or placebo and had to have been started within 24 hours of mechanical ventilation.
These trials mainly measured improvements in oxygenation (Confalonieri 2005), time to resolution of symptoms or time to clinical stability (Cao 2007; Confalonieri 2005; Mikami 2007) and the length of hospital stay or ICU stay (Marik 1993; Mikami 2007; van Woensel 2003). One study measured mortality (Marik 1993). The outcomes of each trial are noted in the Characteristics of included studies table.
Most of the excluded studies were retrospective. Some did not use random allocation and were excluded because the trial author refused to give details of the study. The reasons for exclusion can be found in the Characteristics of excluded studies table.