Table 3: Parameters measured after 1 hour from the start of treatment.
After one hour 
Group C (n = 25)

Group M (n = 25)

Tests 
Mean 
± 
SD 
Mean 
± 
SD 
t/X^{2}

Pvalue 
RR (cycles/min) 
25.84 
± 
3.15 
21.35 
± 
3.5 
4.768 
< 0.001** 
PaO_{2} (mmHg) 
72.67 
± 
4.38 
81.24 
± 
5.09 
6.381 
< 0.001** 
SpO_{2}

93.24 
± 
6.72 
93.56 
± 
7.54 
0.158 
0.874 
pH 
7.25 
± 
0.07 
7.29 
± 
0.09 
1.754 
0.085 
PaCO_{2} (mmHg) 
43.84 
± 
4.8 
44.35 
± 
5.1 
0.364 
0.717 
No. requiring MV 
9/16 (36%) 
3/22 (12%) 
3.947 
0.047* 
Data are presented as mean±standard deviation. Number of patients requiring mechanical ventilation expressed as percentage. Group C: standard pharmacotherapy and placebo, Group M: standard pharmacotherapy and 25 μg milrinone slow IV bolus, MV: mechanical ventilation, RR: respiratory rate, PaO_{2}: arterial partial pressure of oxygen, SpO_{2}: arterial oxygen saturation, pH: potential of hydrogen, PaCO_{2} arterial partial pressure of carbon dioxide.
**Statistically highly significant
*Statistically significant