Author: R. Schumacher, 2009 License: Unless otherwise noted, this material is made available under the terms of the Creative Commons Attribution – Non- Commercial – Share Alike 3.0 License: http://creativecommons.org/licenses/by-nc-sa/3.0/ We have reviewed this material in accordance with U.S. Copyright Law and have tried to maximize your ability to use, share, and adapt it. The citation key on the following slide provides information about how you may share and adapt this material. Copyright holders of content included in this material should contact [email protected]with any questions, corrections, or clarification regarding the use of content. For more information about how to cite these materials visit http://open.umich.edu/education/about/terms-of-use. Any medical information in this material is intended to inform and educate and is not a tool for self-diagnosis or a replacement for medical evaluation, advice, diagnosis or treatment by a healthcare professional. Please speak to your physician if you have questions about your medical condition. Viewer discretion is advised: Some medical content is graphic and may not be suitable for all viewers.
Transcript
Author: R. Schumacher, 2009
License: Unless otherwise noted, this material is made available under the terms of the Creative Commons Attribution – Non-Commercial – Share Alike 3.0 License: http://creativecommons.org/licenses/by-nc-sa/3.0/
We have reviewed this material in accordance with U.S. Copyright Law and have tried to maximize your ability to use, share, and adapt it. The citation key on the following slide provides information about how you may share and adapt this material.
Copyright holders of content included in this material should contact [email protected] with any questions, corrections, or clarification regarding the use of content.
For more information about how to cite these materials visit http://open.umich.edu/education/about/terms-of-use.
Any medical information in this material is intended to inform and educate and is not a tool for self-diagnosis or a replacement for medical evaluation, advice, diagnosis or treatment by a healthcare professional. Please speak to your physician if you have questions about your medical condition.
Viewer discretion is advised: Some medical content is graphic and may not be suitable for all viewers.
Citation Keyfor more information see: http://open.umich.edu/wiki/CitationPolicy
•Newborn respiratory distress syndrome is Newborn respiratory distress syndrome is characterized by low lung volumes.characterized by low lung volumes. Contributing Contributing factors to the low FRC in such patients include:”factors to the low FRC in such patients include:”
a. decreased lung compliancea. decreased lung compliance b. surfactant deficiencyb. surfactant deficiency
c. increased chest wall compliancec. increased chest wall complianced. hey, babies are smalld. hey, babies are smalle. All of the above*e. All of the above*
Review M1
• 2 Dead French Guys
• 1 Dead Swiss Guy
Laplace RelationshipLaplace Relationship• ∆∆P =2γ/r P =2γ/r • Trans-surface pressure = 2(surface tension) / radius of curvatureTrans-surface pressure = 2(surface tension) / radius of curvature
Source Undetermined
Von NeergardVon Neergard• Swiss physicist who demonstrated surface tension forces at work in excised cat Swiss physicist who demonstrated surface tension forces at work in excised cat
lungs. (Air filled v saline filled cat lungs) Laplace relationship holds for alveoli.lungs. (Air filled v saline filled cat lungs) Laplace relationship holds for alveoli.
Source Undetermined
• If this surface film is compressed the phospholipids will be packed more tightly and more water excluded from the surface. This is ideal: the smaller the radius of curvature the more important surface tension forces become (LaPlace), the smaller the radius of curvature the tighter the surfactant molecular pack and the greater the reduction in surface tension forces.
Source Undetermined
Jean L. PoiseuilleJean L. Poiseuille
Poiseuille, Jean Léonard Marie (1799-1869) Poiseuille, Jean Léonard Marie (1799-1869) was a French physiologist who made a key was a French physiologist who made a key contribution to our knowledge of the circulation of contribution to our knowledge of the circulation of blood in the arteries. blood in the arteries.
Poiseuille's Law of The Flow of Liquids Through a Tube:Poiseuille's Law of The Flow of Liquids Through a Tube:Where:Where:l = the length of the tube in cml = the length of the tube in cmr = the radius of the tube in cmr = the radius of the tube in cmp = the difference in pressure of the two ends of the tube in dynes per cm2p = the difference in pressure of the two ends of the tube in dynes per cm2c = the coefficient of Viscosity in poises (dyne-seconds per cm2)c = the coefficient of Viscosity in poises (dyne-seconds per cm2)
v = volume in cm3 per secondv = volume in cm3 per second
shunting” at the shunting” at the level of the atria level of the atria and the ductus and the ductus arteriosus.arteriosus.
Source Undetermined
Source Undetermined
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Source UndeterminedSource Undetermined
Case: #1Case: #1
• Because “it’s the Holidays” and her mother-in-Because “it’s the Holidays” and her mother-in-law will be in town to “help out”, a scheduled law will be in town to “help out”, a scheduled repeat elective cesarean section is performed on repeat elective cesarean section is performed on a woman at 37 weeks gestational age. When a woman at 37 weeks gestational age. When this baby is born he is tachypneic.this baby is born he is tachypneic.
• List as many reasons as you can for the lack of List as many reasons as you can for the lack of clearance of lung fluid.clearance of lung fluid.
• How would you treat this problem?How would you treat this problem?
Transient TachypneaTransient Tachypneaof the Newborn: (TTNB)of the Newborn: (TTNB)• Also know as “Wet Lung, Retained Fetal Also know as “Wet Lung, Retained Fetal
Lung Fluid”.Lung Fluid”.
• Occurs as a consequence of delayed or Occurs as a consequence of delayed or incomplete clearance of fetal lung fluid.incomplete clearance of fetal lung fluid.
• Predisposing/ causative factors:Predisposing/ causative factors:– No labor, c-section, hypoventilation, No labor, c-section, hypoventilation,
Transient Tachypnea of the NewbornTransient Tachypnea of the Newborn
• Lung water content (and weight) is high and an Lung water content (and weight) is high and an increased respiratory rate is energy efficient.increased respiratory rate is energy efficient.
• Signs in infantSigns in infant– tachypneatachypnea
• Treatment Treatment (usual) (usual) ::– none or O2.none or O2.
Transient Tachypnea of the NewbornTransient Tachypnea of the Newborn
No labor During labor
30 minutes of life 6 hours of life
Source Undetermined
Source Undetermined
Transient Tachypnea of the NewbornTransient Tachypnea of the Newborn
Source Undetermined (All Images)
Case: #2Case: #2
• A woman delivers premature twins at 25 A woman delivers premature twins at 25 weeks gestational age. The twins develop weeks gestational age. The twins develop respiratory distress.respiratory distress.– Why is lung volume low in these infants? Why is lung volume low in these infants?
Newborn Respiratory Distress Newborn Respiratory Distress Syndrome (RDS)Syndrome (RDS)• Why does this infant have the following signs:Why does this infant have the following signs:• Tachypnea ?Tachypnea ?
– Minute ventilation is RR x TV. With a compliant chest Minute ventilation is RR x TV. With a compliant chest wall increasing RR is more efficient than taking deeper wall increasing RR is more efficient than taking deeper breaths (increasing TV).breaths (increasing TV).
• Grunting ?Grunting ?– Exhaling against a partially closed glottis provides Exhaling against a partially closed glottis provides
positive end expiratory pressure -maintains lung positive end expiratory pressure -maintains lung volume (FRC).volume (FRC).
• Nasal flaring: Nasal flaring: – On inspiration alae diameter increases to lower On inspiration alae diameter increases to lower
airway resistance.airway resistance.
• Paradoxical breathing: (Paradoxical breathing: (On inspiration the abdomen On inspiration the abdomen pops-up, the chest wall sinkspops-up, the chest wall sinks))– Use of diaphragm with compliant chest wall Use of diaphragm with compliant chest wall
produces negative intra-thoracic pressure, positive produces negative intra-thoracic pressure, positive abdominal pressure, a costly way to breathe.abdominal pressure, a costly way to breathe.
• Retractions: Retractions: – increased use of muscles of respiration = very costly, increased use of muscles of respiration = very costly,
Treat the Cause:Treat the Cause:Artificial surfactantArtificial surfactant
• On day 7 one twin deteriorates. You On day 7 one twin deteriorates. You hear a murmur. hear a murmur. – What is this twin’s problem?What is this twin’s problem?
NIH, United States Department of Health and Human Services
• Occurs as a consequence of a structural Occurs as a consequence of a structural and functional/biochemical immaturity and functional/biochemical immaturity of a infant's lung including:of a infant's lung including:– a relative lack of surfactant a relative lack of surfactant
production.production.– a compliant chest walla compliant chest wall– a variable degree of L to R shunting a variable degree of L to R shunting
through a patent ductus arteriosus.through a patent ductus arteriosus.
Case #3:Case #3:• As a baby shower gift a pregnant woman’s friends As a baby shower gift a pregnant woman’s friends
present her with some crack cocaine. Tired of being present her with some crack cocaine. Tired of being pregnant the woman tries to induce labor by using pregnant the woman tries to induce labor by using the crack. Subsequent severe abdominal pain the crack. Subsequent severe abdominal pain prompts her to seek medical attention. An prompts her to seek medical attention. An emergency c-section is planned. At rupture of emergency c-section is planned. At rupture of membranes there is blood and thick chunky pea-membranes there is blood and thick chunky pea-soup like material seen. The infant is born floppy, soup like material seen. The infant is born floppy, pale with no spontaneous respirations.pale with no spontaneous respirations.
• Think about why and when this baby may have Think about why and when this baby may have problems……..problems……..
Case 3# Meconium Aspiration Case 3# Meconium Aspiration Syndrome.Syndrome.
• After effective resuscitation, the infant is After effective resuscitation, the infant is placed on a ventilator. Shortly thereafter placed on a ventilator. Shortly thereafter you note decreased breath sounds, a shift you note decreased breath sounds, a shift of the PMI, hypotension and profound of the PMI, hypotension and profound cyanosis.cyanosis.
• What has happened? What should you What has happened? What should you do?do?
Pneumothorax from meconium plug
Source Undetermined
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• Having fixed this problem you note Having fixed this problem you note persistent cyanosis. You note curiously persistent cyanosis. You note curiously that the transcutaneous O2 saturation that the transcutaneous O2 saturation monitor gives different readings on the monitor gives different readings on the hands vs feet.hands vs feet.
• What is happening? What can you do?What is happening? What can you do?
Persistent pulmonary hypertension of the newborn Persistent pulmonary hypertension of the newborn (PPHN) is the result of elevated pulmonary (PPHN) is the result of elevated pulmonary vascular resistance to the point that venous blood vascular resistance to the point that venous blood is diverted to some degree through fetal channels is diverted to some degree through fetal channels (i. e. the ductus arteriosus and foramen ovale) into (i. e. the ductus arteriosus and foramen ovale) into the systemic circulation and bypassing the lungs, the systemic circulation and bypassing the lungs, resulting in systemic arterial hypoxemia.resulting in systemic arterial hypoxemia.
Treatment:Treatment:• Fix that which is broken.Fix that which is broken.
– Correct the cause of hypoxia, hypercarbia, Correct the cause of hypoxia, hypercarbia, acidosis. acidosis.
• If it hurts when you go like that, then If it hurts when you go like that, then don’t go like that.don’t go like that.– Avoid over distention of lungs,Avoid over distention of lungs,– BarotraumaBarotrauma
• Attempt to lower PVR.Attempt to lower PVR.– O2, Ventilation, BufferO2, Ventilation, Buffer– Inhaled Nitric Oxide Inhaled Nitric Oxide
• Attempt to raise SVR (and output)Attempt to raise SVR (and output)– Volume expansion for preloadVolume expansion for preload– Vasoconstrictors?Vasoconstrictors?– Inotropic supportInotropic support
Source Undetermined
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