Hello again, (been offline for a week). Regarding mec liquor at birth, again - just the mechanics of it. The baby can not only aspirate from the mec stained liquor at delivery as it emerges from the uterus, it is also possible for the baby to aspirate from it's own gastric contents, i.e. regurgitate. This can happen as it passes through the birth canal/abdomen/water in an attempt to initiate respiration - the result of the Herring Bruer reflex, hypoxic drive. (This is an example only!) A baby does urinate into the liquor, and pass mec, which can be deemed normal according to the previous postings. You only have to take a gastric aspirate on a MSL baby to see how much can be swallowed. Apparently, this gastric content can be forced upwards to the mouth during delivery. You can imagine that if a baby is going to gasp (if distressed, as evidenced by late decelerations on CTG's) and inhale, whatever is in the way at the time will be sucked back past the trachea.
It only takes a very small amount, especially the thick mec, to effectively block off the bronchial tree, or parts thereof. Given the presence of fetal lung fluid and gravity, it is a great transporter of mec down into the alveoli as it gets reabsorbed through all levels of the bronchial tree. Remember that mec is sterile at this point, but by saying that, it sets up a chemical reaction with the surrounding tissues and can damage very quickly, with very little mec. Ever inhaled a little saliva?? Choked nearly?? This is the same sort of reaction the baby has only without the 'cough' reflex so well developed. Suctioning on the peri, as the head emerges possibly goes a long way to preventing aspiration syndrome, but that is only part of the story... Will post references for the above later also (it is not my computer that I am on at present) Primary and secondary apnoea usually refers to extra-uterine resuscitation of the neonate, due to asphyxia in utero. More on that later. Gayle ---- Original Message ---- From: [EMAIL PROTECTED] To: [EMAIL PROTECTED], Subject: Re: [ozmidwifery] Homebirth experiences with Mec liquor Date: Wed, 4 Jun 2003 17:32:14 -0700 >Mary, I agree. I think the answers are theoretical and probably >can't be tested for ethical reasons. I would say theoretically >speaking, babies born through mec liqour would not be in danger of >aspirating mec at birth, if they have done so, they have done so in >utero and no amount of suctioning will help the situation. That >being said, I can imagine that if they had a mouth full of mec that >if it weren't suctioned before the first breath it could be >aspirtated. At least that was the rationale for suctioning on the >perineum in the Seattle practice. But not vigorous suctioning, just >mouth and nose with a de Lee. I can also see that being born in >water would get rid of that mec nicely, which is interesting because >I do know some midwives who have women get out of water to birth if >there is mec liquor, presumably to suction. It boils down to >individual comfort levels (both woman and midwife) and full >disclosure so that there are no shocks when it comes to the birth, >especially in areas such as this where it definetly seems like more >art than science to me. > >marilyn > ----- Original Message ----- > From: Mary Murphy > To: [EMAIL PROTECTED] > Sent: Monday, June 02, 2003 11:08 PM > Subject: Re: [ozmidwifery] Homebirth experiences with Mec liquor > > > Marilyn, it looks like there are still things we have to learn about the subject, regardless of what seems to be factual evidence. I don't really feel that I have a proven answer to my original question, altho I value all the other information put forward. cheers, MM -- This mailing list is sponsored by ACE Graphics. Visit <http://www.acegraphics.com.au> to subscribe or unsubscribe.
