Fetal Distress, Oxygen Inhalation Therapy, Second Stage of Labour
Conditions
Brief summary
Supplementary oxygen is routinely administered to patients, even those with adequate oxygen saturations, in the belief that it increases oxygen delivery. However, oxygen delivery depends not just on arterial oxygen content but also on perfusion. Maternal oxygen administration has been used in an attempt to lessen fetal distress by increasing the available oxygen from the mother. However, the effect of supplemental maternal oxygen therapy on fetal acid base status has been debated for more than seven decades. Hypothesis: Prophylactic maternal low flow nasal oxygen administration during the second stage of labor can relieve fetal distress.
Detailed description
A report from the cochran library (Cochrane Database Syst Rev. 2012 Dec 12;12:CD000136.): Too little evidence to show whether oxygen administration to the woman during labour is beneficial to the baby. Some babies show signs of distress, such as unusual heart rates or the passing of a bowel motion (meconium) during their mother's labour. This may be caused by a lack of oxygen passing from the woman to the baby through the placenta. Sometimes, women may be encouraged to breathe extra oxygen through a facemask (oxygen administration) to increase the oxygen available to the unborn baby. A review of two trials found too little evidence to show whether oxygen administration to the woman during the second stage of labour is beneficial to the baby. No trials of oxygen administration when the baby is showing signs of distress were found. Further research is needed.
Interventions
DEVICELow flow nasal oxygen
Oxygen will be administered by nasal catheter at a flow rate of 2 L/min. The therapy will continue until after delivery
DEVICELow flow room air
Sham: oxygen will be administered by nasal catheter at a flow rate of 0 L/min.
Sponsors
Navy General Hospital, Beijing
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
PREVENTION
Masking
TRIPLE (Subject, Caregiver, Outcomes Assessor)
Eligibility
Sex/Gender
FEMALE
Age
18 Years to 35 Years
Healthy volunteers
Yes
Inclusion criteria
* at term * singleton * primigraida * cephalic presentation * spontaneous or induced labor * normal labor * normal FHR tracings in the first stage * at the onset of second stage
Exclusion criteria
* respiratory disease * cardiovascular disease * diabetes mellitus or insulin-treated gestational diabetes mellitus * hypertension or preeclampsia * oligohydramnios * fetal growth restriction * placental abruption * anemia * disorders in oxygen saturations * received oxygen therapy in the first stage
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| cord arterial pH values (hydrogen ion concentration) less than 7.2 | within 30-60 seconds of birth | Immediately after delivery (within 30-60 seconds of birth), umbilical cord arterial blood gas sample will be obtained. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Apgar score less than 7 | at one and five minutes after birth | The Apgar scale is determined by evaluating the newborn baby on five simple criteria on a scale from 0 to 2, then summing up the five values thus obtained. The resulting Apgar score ranges from 0 to 10. The five criteria are summarized using words chosen to form a backronym (Appearance, Pulse, Grimace, Activity, Respiration). The infant is given a score of 0, 1 or 2. The scores are added up and the total sum is their Apgar score. The test is generally done at one and five minutes after birth, and may be repeated later if the score is and remains low. Scores 7 and above are generally normal, 4 to 6 fairly low, and 3 and below are generally regarded as critically low. |
| maternal radial arterial partial pressure of oxygen | within 30-60 seconds of birth | Immediately after delivery (within 30-60 seconds of birth), radial artery blood gas sample will be obtained. |
| umbilical cord venous partial pressure of oxygen | within 30-60 seconds of birth | Immediately after delivery (within 30-60 seconds of birth), umbilical cord venous blood gas sample will be obtained. |
Other
| Measure | Time frame |
|---|---|
| neonatal resuscitation | within 10 mins of birth |
| cesarean delivery rate | during the second stage of labor |
| serious neonatal morbidity or death | within 28 days of birth |
| neonatal encephalopathy | within 24 hours of birth |
| assisted vaginal delivery | during the second stage of labor |
| maternal dissatisfaction | during the second stage of labor |
| abnormal fetal heart rate tracing | during the second stage of labor |
Countries
China
Outcome results
None listed