3 August 07 - Medical policies versus nature's intent
Google: vitamin k newborn (for opinions not found in the medical literature)
http://www.gentlebirth.org/archives/vitktop.html
Mercer JS, Vohr BR, McGrath MM, Padbury JF, Wallach M, Oh W. Delayed cord
clamping in very preterm infants reduces the incidence of intraventricular
hemorrhage and late-onset sepsis: a randomized, controlled trial. Pediatrics. 2006
Apr;117(4):1235-42.
http://aappolicy.aappublications.org/cgi/content/full/pediatrics;112/1/191
POLICY STATEMENT AAP Publications Reaffirmed, May 2006 American Academy
of Pediatrics PEDIATRICS Vol. 118 No. 3 September 2006, pp. 1266
http://www.womens-health.co.uk/vitk.asp
Lucile Packard Children's Hospital, Stanford University
http://www.lpch.org/DiseaseHealthInfo/HealthLibrary/hrnewborn/hrdn.html
The following are the most common symptoms of hemorrhagic disease of the
newborn. However, each baby may experience symptoms differently. Symptoms may
include:
in progress...
Google: vitamin k newborn (for opinions not found in the medical literature)
http://www.gentlebirth.org/archives/vitktop.html
Mercer JS, Vohr BR, McGrath MM, Padbury JF, Wallach M, Oh W. Delayed cord
clamping in very preterm infants reduces the incidence of intraventricular
hemorrhage and late-onset sepsis: a randomized, controlled trial. Pediatrics. 2006
Apr;117(4):1235-42.
http://aappolicy.aappublications.org/cgi/content/full/pediatrics;112/1/191
POLICY STATEMENT AAP Publications Reaffirmed, May 2006 American Academy
of Pediatrics PEDIATRICS Vol. 118 No. 3 September 2006, pp. 1266
http://www.womens-health.co.uk/vitk.asp
Lucile Packard Children's Hospital, Stanford University
http://www.lpch.org/DiseaseHealthInfo/HealthLibrary/hrnewborn/hrdn.html
The following are the most common symptoms of hemorrhagic disease of the
newborn. However, each baby may experience symptoms differently. Symptoms may
include:
- blood in the baby's bowel movements
- blood in urine
- oozing around the umbilical cord
in progress...
1 August 07 - Summer reading
Evolution of the nervous system / Harvey B. Sarnat, Martin G. Netsky.
New York : Oxford University Press, 1981. 2d ed.
First signals : the evolution of multicellular development / John Tyler Bonner.
Princeton, N.J. : Princeton University Press, c2000.
Absorbed in reading. More later...
Evolution of the nervous system / Harvey B. Sarnat, Martin G. Netsky.
New York : Oxford University Press, 1981. 2d ed.
First signals : the evolution of multicellular development / John Tyler Bonner.
Princeton, N.J. : Princeton University Press, c2000.
Absorbed in reading. More later...
4 August 2007 - Autism One Radio interviews with Teri Arranga
Dr. Morley and I were interviewed by Teri Arranga on Autism One Radio. Following
are links to the interviews, which are each about one hour in duration:
Following are citations to references I mentioned on (a) comparisons of prevalence
statistics for autism and "respiratory depression" at birth, (b) association of autism
with meconium aspiration, and (c) two recent reports on birth asphyxia (or low Apgar
scores) in children later diagnosed with autism.
Dr. Morley and I were interviewed by Teri Arranga on Autism One Radio. Following
are links to the interviews, which are each about one hour in duration:
- Dr. Morley, June 26
- Dr. Simon, July 31
Following are citations to references I mentioned on (a) comparisons of prevalence
statistics for autism and "respiratory depression" at birth, (b) association of autism
with meconium aspiration, and (c) two recent reports on birth asphyxia (or low Apgar
scores) in children later diagnosed with autism.
- References on respiratory depression at birth:
- Baskett TF et al. Predictors of respiratory depression at birth in the
term infant. BJOG. 2006 Jul;113(7):769-74.
- "The rate of respiratory depression at birth with delay in respiration
was 5.2/1000..." p770
- Milsom I et al. Influence of maternal, obstetric and fetal risk factors on
the prevalence of birth asphyxia at term in a Swedish urban population.
Acta Obstet Gynecol Scand. 2002 Oct;81(10):909-17.
- 225/42203 = 5.3 per 1000 cases of asphyxia, defined as Apgar
score<7 at 5 min. Of 227 original cases, 136 were boys and 91 girls.
- CDC autism statistics:
- www.cdc.gov/ncbddd/autism/, and follow prevalence links
- "Most sites identified between 5.2 - 7.6 per 1,000 8-year-old
children with ASD in 2000 and 2002."
- Reference on association of autism with meconium aspiration at birth:
- Matsuishi T et al. Brief report: incidence of and risk factors for autistic
disorder in neonatal intensive care unit survivors. J Autism Dev Disord.
1999 Apr;29(2):161-6.
- Reference on association of autism with complications at birth:
- Glasson EJ, et al. Perinatal factors and the development of autism: a
population study. Arch Gen Psychiatry. 2004 Jun;61(6):618-27.
- Note the authors' conclusion that complications at birth are "most
likely due to the underlying genetic factors or an interaction of
these factors with the environment." What genetic factors? What
in the environment? Where's the evidence for genetic and
environmental factors? The authors do provide evidence of birth
complications among children later diagnosed with autism. What is
feared most about a complicated birth? Isn't it the likelihood of
oxygen insufficiency? Oxygen deficiency at birth has been shown
to damage the auditory pathway in the midbrain, which should be
considered as a likely impediment to speech development.
- Reference on association of autism with hypoxic-ischemic encephalopathy:
- Badawi N et al. Autism following a history of newborn encephalopathy:
more than a coincidence? Dev Med Child Neurol. 2006 Feb;48(2):85-9.
8 August 2007 - Job search seminar, and resume (working version) posted
Few jobs could be more interesting that what I do at Bridgewater State Hospital. I
attended orientation one week ago, required by the new contractor for mental health
services, Mental Health Management Correctional Services (MHM), and I do like
their humane philosophy. However, having started to look around (in large part
because the commute to Bridgewater seems worse and worse, especially in winter),
I have signed up for a series of seminars at the Career Source Center in Cambridge
MA. Yesterday, I was struck with the suggestion of maintaining a sense of mission.
My work at Bridgewater is certainly motivated by a sense of mission, but I am in such
a powerless situation there.
Today, I will take my resume to an interview, at the Career Source center, with a
recruiter for pharmaceutical and biotech companies. I have tried to put some "sizzle
words" in my resume, as also suggested in the seminar, and am posting a working
version online at http://www.inferiorcolliculus.org/07resumeworking.html
Few jobs could be more interesting that what I do at Bridgewater State Hospital. I
attended orientation one week ago, required by the new contractor for mental health
services, Mental Health Management Correctional Services (MHM), and I do like
their humane philosophy. However, having started to look around (in large part
because the commute to Bridgewater seems worse and worse, especially in winter),
I have signed up for a series of seminars at the Career Source Center in Cambridge
MA. Yesterday, I was struck with the suggestion of maintaining a sense of mission.
My work at Bridgewater is certainly motivated by a sense of mission, but I am in such
a powerless situation there.
Today, I will take my resume to an interview, at the Career Source center, with a
recruiter for pharmaceutical and biotech companies. I have tried to put some "sizzle
words" in my resume, as also suggested in the seminar, and am posting a working
version online at http://www.inferiorcolliculus.org/07resumeworking.html
14 August 2007 - Outcome at age 5 of children with complications at birth
Bahl R, Patel RR, Swingler R, Ellis M, Murphy DJ. Neurodevelopmental outcome at
5 years after operative delivery in the second stage of labor: a cohort study. Am J
Obstet Gynecol. 2007 Aug;197(2):147.e1-6.
"The questionnaires are available on the Avon Longitudinal Study in Parents and
Children website (www.alspac.bris.ac.uk/alspacExt/)." [p e2] -- I was unable to link to
the web page given, so changed its link to the Avon Longitudinal Study of Parents
and Children (alspac) home page.
"We recruited a prospective cohort of 393 women with term singleton cephalic
pregnancies who required operative delivery at full dilation between February 1999
and February 2000." [p e2]
"There were 66 babies who were born with an Apgar score of <7 at 5 minutes, an
umbilical artery pH <7.10, significant trauma, and/or suspected sepsis or who
needed admission to SCBU." [p e2]
"Two hundred sixty-three women from the original cohort of 393 women (67%) who
underwent operative delivery returned postal questionnaires at 5 years." [p e3]
"There was a higher incidence of hearing problems reported by mothers in the
instrument vaginal delivery group, when compared with the immediate cesarean
delivery group (odds ratio, 3.68; 95% CI, 1.22, 11.1). The difference remained
significant when adjusted for gestational age at delivery, gender, and birthweight of
the baby (odds ratio, 3.51; 95% CI, 1.15, 10.69). However, the reported hearing
problems in most cases related to referral for formal audiologic testing after poor
response at initial distraction hearing test, a common feature of this test. The only
case of audiologically confirmed hearing loss was reported in a child who was born
by cesarean delivery and was attributed to bacterial meningitis at 2 years of age."
[p e4]
"The 2 children with adverse neurodevelopmental outcomes had evidence of causal
factors that predated the mode of delivery. The findings of this study should provide
reassurance to parents who are faced with complex instrument delivery or cesarean
delivery in the second stage of labor." [p e6]
Bahl R, Patel RR, Swingler R, Ellis M, Murphy DJ. Neurodevelopmental outcome at
5 years after operative delivery in the second stage of labor: a cohort study. Am J
Obstet Gynecol. 2007 Aug;197(2):147.e1-6.
"The questionnaires are available on the Avon Longitudinal Study in Parents and
Children website (www.alspac.bris.ac.uk/alspacExt/)." [p e2] -- I was unable to link to
the web page given, so changed its link to the Avon Longitudinal Study of Parents
and Children (alspac) home page.
"We recruited a prospective cohort of 393 women with term singleton cephalic
pregnancies who required operative delivery at full dilation between February 1999
and February 2000." [p e2]
"There were 66 babies who were born with an Apgar score of <7 at 5 minutes, an
umbilical artery pH <7.10, significant trauma, and/or suspected sepsis or who
needed admission to SCBU." [p e2]
"Two hundred sixty-three women from the original cohort of 393 women (67%) who
underwent operative delivery returned postal questionnaires at 5 years." [p e3]
"There was a higher incidence of hearing problems reported by mothers in the
instrument vaginal delivery group, when compared with the immediate cesarean
delivery group (odds ratio, 3.68; 95% CI, 1.22, 11.1). The difference remained
significant when adjusted for gestational age at delivery, gender, and birthweight of
the baby (odds ratio, 3.51; 95% CI, 1.15, 10.69). However, the reported hearing
problems in most cases related to referral for formal audiologic testing after poor
response at initial distraction hearing test, a common feature of this test. The only
case of audiologically confirmed hearing loss was reported in a child who was born
by cesarean delivery and was attributed to bacterial meningitis at 2 years of age."
[p e4]
"The 2 children with adverse neurodevelopmental outcomes had evidence of causal
factors that predated the mode of delivery. The findings of this study should provide
reassurance to parents who are faced with complex instrument delivery or cesarean
delivery in the second stage of labor." [p e6]
18 August 2007 - BMJ editorial: Umbilical cord clamping ... Better not to rush
Umbilical cord clamping after birth: Better not to rush.
Andrew Weeks, senior lecturer in obstetrics School of Reproductive and
Developmental Medicine, University of Liverpool.
BMJ 2007;335:312-313
Excerpts:
"Early clamping and cutting of the umbilical cord is widely practised as part of the
management of labour, but recent studies suggest that it may be harmful to the
baby. So should we now delay the clamping?
Early clamping of the cord was one of the first routine medical interventions in
labour. Its place in modern births was guaranteed by its incorporation into the triad
of interventions that make up the active management of the third stage of labour.
The earliest references are clear about the other two components of active
management—oxytocin to contract the uterus and prevent postpartum
haemorrhage, and controlled cord traction to prevent retention of the placenta (1).
But early cord clamping had no specific rationale, and it probably entered the
protocol by default because it was already part of standard practice. When this
package was shown to reduce postpartum haemorrhage in the 1980s early cord
clamping became enshrined in the modern management of labour." [p312]
"So what is the evidence behind cord clamping? For the mother, trials show that
early cord clamping has no effect on the risk of retained placenta or postpartum
haemorrhage (3, 4)." [p312]
"But what about the baby? Initially, the cord blood continues to flow, sending
oxygenated blood back to the fetus while respiration becomes established, ensuring
a good handover between the respiratory systems. At the time of the first fetal
breath, however, the reduction in intrathoracic pressure draws blood into the lungs
from the umbilical vein...(6)" [p312]
"For the term baby, the main effect of this large autotransfusion is to increase iron
status and shift the normal curve of the neonatal haematocrit to the right. This may
be life saving in areas where anaemia is endemic. Here, late cord clamping
increases the average haemoglobin concentration by 11 g/l at four months (9). In
the developed world, however, there have been concerns that it could increase the
risk of neonatal polycythaemia and hyperbilirubinaemia. Trials show this is not the
case. Delayed cord clamping seems to drive up mean haematocrit values and serum
concentrations of bilirubin, without increasing the number of infants needing
treatment for jaundice or polycythaemia (7)." [p312-313]
"How should we approach cord clamping in practice? In normal deliveries, delaying
cord clamping for three minutes with the baby on the mother’s abdomen should not
be too difficult. The situation is a little more complex for babies born by caesarean
section or for those who need support soon after birth. Nevertheless, it is these
babies who may benefit most from a delay in cord clamping." [p313]
"There is now considerable evidence that early cord clamping does not benefit
mothers or babies and may even be harmful. Both the World Health Organization
and the International Federation of Gynecology and Obstetrics (FIGO) have
dropped the practice from their guidelines." [p313]
"In these days of advanced technology, it is surely not beyond us to find a way of
keeping the cord intact during the first minute of neonatal resuscitation." [p313]
References:
1 Spencer PM. Controlled cord traction in management of the third stage of labour.
BMJ 1962;1:1728-32.
2 Winter C, Macfarlane A, Deneux-Tharaux C, Zhang W-H, Alexander S,
Brocklehurst P, et al. Variations in policies for management of the third stage of
labour and the immediate management of postpartum haemorrhage in Europe.
BJOG 2007;114:845-54.
3 Oxford Midwives Research Group. A study of the relationship between the delivery
to cord clamping interval and the time of cord separation. Midwifery 1991;7:167-76.
4 Ceriani Cernadas JM, Carroli G, Pellegrini L, Otano L, Ferreira M, Ricci C, et al.
The effect of timing of cord clamping on neonatal venous hematocrit values and
clinical outcome at term: a randomized, controlled trial. Pediatrics 2006;117:e779-86.
5 Cotter A, Ness A, Tolosa J. Prophylactic oxytocin for the third stage of labour.
Cochrane Database Syst Rev 2001;(4):CD001808.
6 Yao AC, Hirvensalo M, Lind J. Placental transfusion rate and uterine contraction.
Lancet 1968;1:380-3.
7 Hutton EK, Hassan ES. Late vs early clamping of the umbilical cord in full-term
neonates. Systematic review and meta-analysis of controlled trials. JAMA 2007;297:
1241-52.
8 Yao AC, Lind J. Effect of gravity on placental transfusion. Lancet 1969;2:505-8.
9 Van Rheenen P, de Moor L, Eschbach S, de Grooth H, Brabin B. Delayed cord
clamping and haemoglobin levels in infancy: a randomised controlled trial in term
babies. Trop Med Int Health 2007;12:603-16.
10 Rabe H, Reynolds G, Diaz-Rossello J. Early versus delayed umbilical cord
clamping in preterm infants. Cochrane Database Syst Rev 2004;(4):CD003248.
11 Van Rheenen PF, Brabin BJ. A practical approach to timing cord clamping in
resource poor settings. BMJ 2006;333:954-8.
12 Lievaart M, de Jong PA. Acid-base equilibrium in umbilical cord blood and time of
cord clamping. Obstet Gynecol 1984;63:44-7.
Umbilical cord clamping after birth: Better not to rush.
Andrew Weeks, senior lecturer in obstetrics School of Reproductive and
Developmental Medicine, University of Liverpool.
BMJ 2007;335:312-313
Excerpts:
"Early clamping and cutting of the umbilical cord is widely practised as part of the
management of labour, but recent studies suggest that it may be harmful to the
baby. So should we now delay the clamping?
Early clamping of the cord was one of the first routine medical interventions in
labour. Its place in modern births was guaranteed by its incorporation into the triad
of interventions that make up the active management of the third stage of labour.
The earliest references are clear about the other two components of active
management—oxytocin to contract the uterus and prevent postpartum
haemorrhage, and controlled cord traction to prevent retention of the placenta (1).
But early cord clamping had no specific rationale, and it probably entered the
protocol by default because it was already part of standard practice. When this
package was shown to reduce postpartum haemorrhage in the 1980s early cord
clamping became enshrined in the modern management of labour." [p312]
"So what is the evidence behind cord clamping? For the mother, trials show that
early cord clamping has no effect on the risk of retained placenta or postpartum
haemorrhage (3, 4)." [p312]
"But what about the baby? Initially, the cord blood continues to flow, sending
oxygenated blood back to the fetus while respiration becomes established, ensuring
a good handover between the respiratory systems. At the time of the first fetal
breath, however, the reduction in intrathoracic pressure draws blood into the lungs
from the umbilical vein...(6)" [p312]
"For the term baby, the main effect of this large autotransfusion is to increase iron
status and shift the normal curve of the neonatal haematocrit to the right. This may
be life saving in areas where anaemia is endemic. Here, late cord clamping
increases the average haemoglobin concentration by 11 g/l at four months (9). In
the developed world, however, there have been concerns that it could increase the
risk of neonatal polycythaemia and hyperbilirubinaemia. Trials show this is not the
case. Delayed cord clamping seems to drive up mean haematocrit values and serum
concentrations of bilirubin, without increasing the number of infants needing
treatment for jaundice or polycythaemia (7)." [p312-313]
"How should we approach cord clamping in practice? In normal deliveries, delaying
cord clamping for three minutes with the baby on the mother’s abdomen should not
be too difficult. The situation is a little more complex for babies born by caesarean
section or for those who need support soon after birth. Nevertheless, it is these
babies who may benefit most from a delay in cord clamping." [p313]
"There is now considerable evidence that early cord clamping does not benefit
mothers or babies and may even be harmful. Both the World Health Organization
and the International Federation of Gynecology and Obstetrics (FIGO) have
dropped the practice from their guidelines." [p313]
"In these days of advanced technology, it is surely not beyond us to find a way of
keeping the cord intact during the first minute of neonatal resuscitation." [p313]
References:
1 Spencer PM. Controlled cord traction in management of the third stage of labour.
BMJ 1962;1:1728-32.
2 Winter C, Macfarlane A, Deneux-Tharaux C, Zhang W-H, Alexander S,
Brocklehurst P, et al. Variations in policies for management of the third stage of
labour and the immediate management of postpartum haemorrhage in Europe.
BJOG 2007;114:845-54.
3 Oxford Midwives Research Group. A study of the relationship between the delivery
to cord clamping interval and the time of cord separation. Midwifery 1991;7:167-76.
4 Ceriani Cernadas JM, Carroli G, Pellegrini L, Otano L, Ferreira M, Ricci C, et al.
The effect of timing of cord clamping on neonatal venous hematocrit values and
clinical outcome at term: a randomized, controlled trial. Pediatrics 2006;117:e779-86.
5 Cotter A, Ness A, Tolosa J. Prophylactic oxytocin for the third stage of labour.
Cochrane Database Syst Rev 2001;(4):CD001808.
6 Yao AC, Hirvensalo M, Lind J. Placental transfusion rate and uterine contraction.
Lancet 1968;1:380-3.
7 Hutton EK, Hassan ES. Late vs early clamping of the umbilical cord in full-term
neonates. Systematic review and meta-analysis of controlled trials. JAMA 2007;297:
1241-52.
8 Yao AC, Lind J. Effect of gravity on placental transfusion. Lancet 1969;2:505-8.
9 Van Rheenen P, de Moor L, Eschbach S, de Grooth H, Brabin B. Delayed cord
clamping and haemoglobin levels in infancy: a randomised controlled trial in term
babies. Trop Med Int Health 2007;12:603-16.
10 Rabe H, Reynolds G, Diaz-Rossello J. Early versus delayed umbilical cord
clamping in preterm infants. Cochrane Database Syst Rev 2004;(4):CD003248.
11 Van Rheenen PF, Brabin BJ. A practical approach to timing cord clamping in
resource poor settings. BMJ 2006;333:954-8.
12 Lievaart M, de Jong PA. Acid-base equilibrium in umbilical cord blood and time of
cord clamping. Obstet Gynecol 1984;63:44-7.
19 August 2007 - BMJ editorial: Umbilical cord clamping ... Responses
Posted at:
http://www.bmj.com/cgi/eletters/335/7615/312
Looking for more on: (1) transfusion from placenta to alveolar capillaries and
(2) release of carbon dioxide into the newly opened alveoli to be exhaled before
inhalation of the first breath:
PubMed: hemoglobin & respiration & newborn & lungs (or alveoli)
Google:
Irzhak LI. Christian Bohr (On the Occasion of the 150th Anniversary of His Birth)
Human Physiology, Vol. 31, No. 3, 2005, pp. 366–368. Translated from Fiziologiya
Cheloveka, Vol. 31, No. 3, 2005, pp. 139–141.
Pulmonary and respiratory physiology / edited by Julius H. Comroe, Jr. ; with the
assistance of Karen Kreller. Stroudsburg, Pa. : Dowden, Hutchinson & Ross ; [New
York] : distributed by Halsted Press, c1976. LOC call # QP121 .P77
(cited by Irzhak -- includes papers by Bohr translated into English)
http://www.merck.com/mmpe/sec19/ch271/ch271a.html
"Cardiovascular: Fetal circulation is marked by right-to-left shunting of blood around
unoxygenated lungs through a patent ductus arteriosus (connecting the pulmonary
artery to the aorta) and foramen ovale (connecting the right and left atria). Shunting
is encouraged by high pulmonary arteriolar resistance and relatively low resistance
to blood flow in the systemic (including placental) circulation. About 90 to 95% of the
right heart output bypasses the lungs and goes directly to the systemic circulation.
The fetal ductus arteriosus is kept open by low fetal systemic Pao2 (about 25 mm
Hg) along with locally produced prostaglandins. The foramen ovale is kept open by
differences in atrial pressures: left atrial pressure is relatively low because little
blood is returned from the lungs, but right atrial pressure is relatively high because
large volumes of blood return from the placenta.
Profound changes to this system occur after the first few breaths, resulting in
increased pulmonary blood flow and closure of the foramen ovale. Pulmonary
arteriolar resistance drops acutely as a result of vasodilation caused by lung
expansion, increased Pao2, and reduced Paco2. The elastic forces of the ribs and
chest wall decrease pulmonary interstitial pressure, further enhancing blood flow
through pulmonary capillaries.
As pulmonary blood flow is established, venous return from the lungs increases,
raising left atrial pressure. Air breathing increases the Pao2, which constricts the
umbilical arteries. Placental blood flow is reduced or stops, reducing blood return to
the right atrium. Thus, right atrial pressure decreases while left atrial pressure
increases; as a result, the foramen ovale closes.
Soon after birth, systemic resistance becomes higher than pulmonary resistance, a
reversal from the fetal state. Therefore, the direction of blood flow through the
patent ductus arteriosus reverses, creating left-to-right shunting of blood (called
transitional circulation). This state lasts from moments after birth (when the
pulmonary blood flow increases and functional closure of the foramen ovale occurs)
until about 24 to 72 h of age, when the ductus arteriosus usually closes. Blood
entering the ductus and its vasa vasorum from the aorta has a high Po2, which,
along with alterations in prostaglandin metabolism, leads to constriction and closure
of the ductus arteriosus. Once the ductus arteriosus closes, an adult-type circulation
exists. The 2 ventricles now pump in series, and there are no major shunts between
the pulmonary and systemic circulations.
During the days immediately after birth, a stressed neonate may revert to a fetal-
type circulation. Asphyxia with hypoxia and hypercarbia causes the pulmonary
arterioles to constrict and the ductus arteriosus to dilate, reversing the processes
described above and resulting in right-to-left shunting through the now-patent
ductus arteriosus, the reopened foramen ovale, or both. Consequently, the neonate
becomes severely hypoxemic, a condition called persistent pulmonary hypertension
or persistent fetal circulation (although there is no umbilical circulation). The goal of
treatment is to reverse the conditions that produced pulmonary vasoconstriction."
Posted at:
http://www.bmj.com/cgi/eletters/335/7615/312
Looking for more on: (1) transfusion from placenta to alveolar capillaries and
(2) release of carbon dioxide into the newly opened alveoli to be exhaled before
inhalation of the first breath:
PubMed: hemoglobin & respiration & newborn & lungs (or alveoli)
- Crance JP, Bouverot P. [Respiration in the newborn. Recall of some
concepts of physiology] Ann Pediatr (Paris). 1970 Mar 2;17(3):165-73.
(Annales de pédiatrie) - Bouverot P, Crance JP, Dejours P. Factors influencing the intensity of the
Breuer-Hering inspiration-inhibiting reflex. Respir Physiol. 1970 Mar;8(3):
376-84.(Respiration Physiology) - Assali NS, Johnson GH, Brinkman CR 3rd, Kirschbaum TH. Control of
pulmonary and systemic vasomotor tone in the fetus and neonate. Am J
Obstet Gynecol. 1970 Nov 1;108(5):761-72. - Pang LM, Mellins RB. Neonatal cardiorespiratory physiology.
Anesthesiology. 1975 Aug;43(2):171-96.
Google:
Irzhak LI. Christian Bohr (On the Occasion of the 150th Anniversary of His Birth)
Human Physiology, Vol. 31, No. 3, 2005, pp. 366–368. Translated from Fiziologiya
Cheloveka, Vol. 31, No. 3, 2005, pp. 139–141.
Pulmonary and respiratory physiology / edited by Julius H. Comroe, Jr. ; with the
assistance of Karen Kreller. Stroudsburg, Pa. : Dowden, Hutchinson & Ross ; [New
York] : distributed by Halsted Press, c1976. LOC call # QP121 .P77
(cited by Irzhak -- includes papers by Bohr translated into English)
http://www.merck.com/mmpe/sec19/ch271/ch271a.html
"Cardiovascular: Fetal circulation is marked by right-to-left shunting of blood around
unoxygenated lungs through a patent ductus arteriosus (connecting the pulmonary
artery to the aorta) and foramen ovale (connecting the right and left atria). Shunting
is encouraged by high pulmonary arteriolar resistance and relatively low resistance
to blood flow in the systemic (including placental) circulation. About 90 to 95% of the
right heart output bypasses the lungs and goes directly to the systemic circulation.
The fetal ductus arteriosus is kept open by low fetal systemic Pao2 (about 25 mm
Hg) along with locally produced prostaglandins. The foramen ovale is kept open by
differences in atrial pressures: left atrial pressure is relatively low because little
blood is returned from the lungs, but right atrial pressure is relatively high because
large volumes of blood return from the placenta.
Profound changes to this system occur after the first few breaths, resulting in
increased pulmonary blood flow and closure of the foramen ovale. Pulmonary
arteriolar resistance drops acutely as a result of vasodilation caused by lung
expansion, increased Pao2, and reduced Paco2. The elastic forces of the ribs and
chest wall decrease pulmonary interstitial pressure, further enhancing blood flow
through pulmonary capillaries.
As pulmonary blood flow is established, venous return from the lungs increases,
raising left atrial pressure. Air breathing increases the Pao2, which constricts the
umbilical arteries. Placental blood flow is reduced or stops, reducing blood return to
the right atrium. Thus, right atrial pressure decreases while left atrial pressure
increases; as a result, the foramen ovale closes.
Soon after birth, systemic resistance becomes higher than pulmonary resistance, a
reversal from the fetal state. Therefore, the direction of blood flow through the
patent ductus arteriosus reverses, creating left-to-right shunting of blood (called
transitional circulation). This state lasts from moments after birth (when the
pulmonary blood flow increases and functional closure of the foramen ovale occurs)
until about 24 to 72 h of age, when the ductus arteriosus usually closes. Blood
entering the ductus and its vasa vasorum from the aorta has a high Po2, which,
along with alterations in prostaglandin metabolism, leads to constriction and closure
of the ductus arteriosus. Once the ductus arteriosus closes, an adult-type circulation
exists. The 2 ventricles now pump in series, and there are no major shunts between
the pulmonary and systemic circulations.
During the days immediately after birth, a stressed neonate may revert to a fetal-
type circulation. Asphyxia with hypoxia and hypercarbia causes the pulmonary
arterioles to constrict and the ductus arteriosus to dilate, reversing the processes
described above and resulting in right-to-left shunting through the now-patent
ductus arteriosus, the reopened foramen ovale, or both. Consequently, the neonate
becomes severely hypoxemic, a condition called persistent pulmonary hypertension
or persistent fetal circulation (although there is no umbilical circulation). The goal of
treatment is to reverse the conditions that produced pulmonary vasoconstriction."
24 August 2007 - BMJ editorial: Umbilical cord clamping ... More responses
Posted at:
http://www.bmj.com/cgi/eletters/335/7615/312
Two responses yesterday (Aug 23) are cause for concern about following "accepted
medical advice" on any health issue.
The first, from a gynecologist, expressed concerns about hep B and HIV
transmission, stating that the mother to child barriers are destroyed during childbirth.
But, the placental barrier is breached only because clamping the umbilical cord
causes fetal blood to backup into the placenta. If the cord is not touched until
delivery of the placenta, the placental blood will all have been transferred to the
baby's lungs, which is nature's way of initiating breathing in the newborn.
Waiting for full transfer of placental blood to the infant will prevent any backup, or
bursting of placental capillaries. No placental (fetal) blood will leak out into the
maternal circulation, and the maternal immune system will also not go to work
creating antibodies against foreign factors from her child's blood -- and Rh is only
one such antigen.
The second response, from a midwife research institute, reiterates the chant that
"current evidence" is not conclusive enough to justify a change in universal practice.
What about all the research evidence published over the past century about the
physiology of transition from placental to pulmonary respiration? And, damage to
the auditory system of the brain caused by a lapse in respiration? Why do
developmental researchers ignore the evidence of damage to the auditory system,
and how this might impede a child's learning to speak?
My greatest regret is having put trust in the knowledge of the doctors who delivered
my babies. Now I begin to understand the basis of "autoimmune" problems, of
which I am sure must have affected each successive pregnancy. I am grateful that
somehow my two younger sons appear to have escaped any major health problems
that might have been caused by maternal antibodies.
Posted at:
http://www.bmj.com/cgi/eletters/335/7615/312
Two responses yesterday (Aug 23) are cause for concern about following "accepted
medical advice" on any health issue.
The first, from a gynecologist, expressed concerns about hep B and HIV
transmission, stating that the mother to child barriers are destroyed during childbirth.
But, the placental barrier is breached only because clamping the umbilical cord
causes fetal blood to backup into the placenta. If the cord is not touched until
delivery of the placenta, the placental blood will all have been transferred to the
baby's lungs, which is nature's way of initiating breathing in the newborn.
Waiting for full transfer of placental blood to the infant will prevent any backup, or
bursting of placental capillaries. No placental (fetal) blood will leak out into the
maternal circulation, and the maternal immune system will also not go to work
creating antibodies against foreign factors from her child's blood -- and Rh is only
one such antigen.
The second response, from a midwife research institute, reiterates the chant that
"current evidence" is not conclusive enough to justify a change in universal practice.
What about all the research evidence published over the past century about the
physiology of transition from placental to pulmonary respiration? And, damage to
the auditory system of the brain caused by a lapse in respiration? Why do
developmental researchers ignore the evidence of damage to the auditory system,
and how this might impede a child's learning to speak?
My greatest regret is having put trust in the knowledge of the doctors who delivered
my babies. Now I begin to understand the basis of "autoimmune" problems, of
which I am sure must have affected each successive pregnancy. I am grateful that
somehow my two younger sons appear to have escaped any major health problems
that might have been caused by maternal antibodies.
25 August 2007 - BMJ editorial: Summarized in the Telegraph.co.uk
Article at:
http://www.telegraph.co.uk/news/main.jhtml?xml=/news/2007/08/17/ncord117.xml
Yesterday, heading to the library, a traffic mess led me to detour through South
Boston, my old rush-hour route to UMass and Laboure College. The USS
Constitution (Old Ironsides) was in the harbor. So off I went, camera in hand,
around Pleasure Bay to Castle Island to join the crowd of onlookers, and snap some
pictures.
Responses to the BMJ editorial hung in my mind. As the magnificent old ship came
in, and began booming a 21-gun salute, I realized how important history is to most
people. Why has the field of medicine forgotten its history? Could anyone imagine
a statement such as, "Current evidence does not support the idea that wind power
can supply the energy needed by large ships?"
Article at:
http://www.telegraph.co.uk/news/main.jhtml?xml=/news/2007/08/17/ncord117.xml
Yesterday, heading to the library, a traffic mess led me to detour through South
Boston, my old rush-hour route to UMass and Laboure College. The USS
Constitution (Old Ironsides) was in the harbor. So off I went, camera in hand,
around Pleasure Bay to Castle Island to join the crowd of onlookers, and snap some
pictures.
Responses to the BMJ editorial hung in my mind. As the magnificent old ship came
in, and began booming a 21-gun salute, I realized how important history is to most
people. Why has the field of medicine forgotten its history? Could anyone imagine
a statement such as, "Current evidence does not support the idea that wind power
can supply the energy needed by large ships?"
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