The effect of posture on oxygen saturation and respiratory status in postextubated preterm infants.

A crossover, quasi-experimental design was conducted to evaluate the optimal posture among four positions (supine, prone, left lateral, and right lateral) in preterm infants within 48 hours postextubation. Oxygen saturation, respiratory rate, and Silverman-Anderson retraction score were utilized to evaluate the optimal posture. Fifteen preterm infants, thirteen male and two female, with a mean birthweight of 1,251 g (range 610-1,800 g), a mean postnatal age of 18.87 days (range 2-39 days), and a mean postextubation period of 23.5 hours (range 6-38 hours) were studied. Seven infants suffered respiratory failure from respiratory distress syndrome, three from pneumonia, two from perinatal asphyxia, and one from each of the following disorders: patent ductus arteriosus, pneumothorax, and apnea. Each infant was randomly assigned to each position. Oxygen saturation, respiratory rate, and Silverman-Anderson retraction score were recorded when the seconds. Significant differences in mean oxygen saturation and Silverman-Anderson retraction score were not detected for any positions (p = 0.377 and p = 0.51, respectively) but postures did influence respiratory rate (p = 0.001). The mean respiratory rate was 58.9 breaths per minute (bpm) in left lateral position, and 59.9 bpm in right lateral position both being significantly higher than the mean respiratory rate of 54.2 npm in supine position (p = 0.003 and 0.007, respectively). In prone position, the mean respiratory rate was 57.2 bpm which was not significantly different from the mean respiratory rate in supine position (p = 0.059). We conclude that the appropriate posture for preterm infants during the 48-hour postextubation period is all four postures positioned alternately. It there is any deterioration in oxygen saturation in any particular posture, that specific posture should be avoided.

The efficiency of the siriraj blood warmer for in-line blood warming.

The efficiency of the Siriraj Blood Warmer invented by the investigators was evaluated. The warmer operates by heat exchange with a water-bath at 39.50 C. The blood is warmed during its passage through a 270-cm blood warming coil which is in the water-bath. Simulation of massive transfusion and exchange transfusion was performed by using water in a 500-ml bottle refrigerated at 40 C for 24 hours. A blood transfusion set was attached to the bottle and a blood warming coil. A three-way stopcock (the proximal stopcock) connected the blood warming coil to the female adaptor end of a 50-cm extension set. Another three-way stopcock (the distal stopcock) was placed to the male adaptor end of the extenaion set. A 2-ml syringe where the temperature of the water passing through was recorded was attached to each three-way stopcock. The Terumo Infusion Pump was used to control the flow rate at 200, 250, and 300 ml/hr for massive transfusion. Either a 5-ml or a 10-ml syringe was attached to the proximal three-way stopcock for the push-pull technique of exchange transfusion. The water temperature was recorded every minute for 15 minutes. The moan water temperatures at the proximal syringe were 37.98 + 0.030 C, 38.19 + 0.030 C, 38.21 + 0.50 C for the flow rates of 200, 300 ml/hr, respectively, and 36.2 + 0.20 C, 37.2 + 0.20 C for the flow when using the 5-ml and the 10ml syringes, respectively. The mean water temperatures at the distal syringe decreased to 32.1 + 0.10 C, 33.0 + 0.10 C, 33.8 + 0.10 C, 32.4 + 0.30 C, and 35.7 + 0.30 C, respectively. The water temperatures were directly related to the flow rates, but the mean differences between the water temperatures were inversely related to the flow rate. Fifteen pairs of blood samples drawn from 15 units of whole blood before and immediately after free haemoglobin were not statistically significant. The Siriraj Blood Warmer can work very efficiently in warming blood for massive and exchange transfusions and does not make a significant change in plasma potassium or increase haemolysis.

The effect of vertical pulsating stimulation on apnea of prematurity.

Placing preterm infants suffering idiopathic apnea of prematurity on the VPS had an effect on the infants' respiratory effort and achieved a reduction in the number of apneic episodes secondary to central and mixed apnea. However, VPS offered no benefits in the reduction of obstructive apnea in this study population. Because central apnea has been reported as the predominant type of apnea and VPS is a nontoxic, noninvasive, and easy-to-implement method of alleviating central and mixed apnea types, it seems prudent to give VPS which has the stimulus characteristics to preterm infants experiencing apnea of prematurity before other treatment modalities currently in use are tried. Further studies are warranted to determine if VPS is effective in a continuous long-term treatment for apnea of prematurity, for example, until the end of apnea.

High-frequency flow interruption in the rescue of preterm infants with severe RDS.

High-frequency flow interruption (HFFI) was used successfully to rescue three preterm infants with severe respiratory distress syndrome (RDS) whose clinical condition continued to deteriorate while on the conventional mechanical ventilation. Had the HFFI not been used, the survival chances might have been 25 per cent for Case 1 and 2, and 45.5 per cent for Case 3. A dramatic, immediate, and sustained improvement in ventilation and oxygenation was demonstrated once the critical frequency and amplitude of HFFI were established. Bronchopulmonary dysplasia which was already evidenced in one infant before the HFFI attempt was detected in two infants. This study demonstrates that HFFI is capable of achieving adequate gas exchange and improving survival in infants with severe RDS.