Efectos fetales de la anestesia espinal materna


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Efectos fetales de la anestesia espinal materna. Dr. Alberto López Bascope

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Efectos fetales de la anestesia espinal materna

  1. 1. 1. Anestesia Regional en Obstetricia: qué repercusión existe en la dualidad Materno/Fetal?2. Cómo afecta la hipotensión en la Anestesia Espinal?3. Analizar brevemente la circulación fetal.2. Revisar la fisiología de la Oxigenación fetal.3. Qué implicaciones prácticas se pueden concluir?.
  2. 2. Haggard HW: 1929 Devils, Drugs, and Doctors: The Theory of theScience of Healing from Medicine Man to Doctor
  3. 3. Porque oí un grito como de mujer de parto, angustia como de primeriza; era el grito de la hija de Sion que se ahogaba, y extendía sus manos, diciendo: ¡Ay ahora de mí, porque desfallezco ante los asesinos! Jeremías 4:31
  4. 4. 1. Parto o Cesárea?2. Cuánto tiempo se dispone?3. Cuál es el pronóstico del niño?4. Condición anatómo/fisiológica de la madre?5. Opciones Anestésicas:• Anestesia General• Anestesia Regional:1. Espinal2. Peridural3. Mixta
  5. 5. Factores que afectan la transferencia placentaria de medicamentos (Materno/Fetal)Drogas que cruzan la Placenta
  6. 6. A 1995 landmark study by Riley established the advantages of spi- nal compared with epidural anesthesia for cesarean delivery. 1. Riley ET, Cohen SE, Macario A, Desai JB, Ratner EF. Spinal versus epidural anesthesia for cesarean section: a comparison of time efficiency, costs, charges, and complications. Anesth Analg 1995;80:709–12 2. Riley ET. Spinal anaesthesia for Caesarean delivery: keep the pressure up and don’t spare the vasoconstrictors. Br J Anaesth,2004;92:459–61. Neuraxial Anesthesia for Cesarean Delivery: What Criteria Define the “Optimal” Technique? Dan Benhamou, MD, Anesth & Analg, Vol. 109, No. 5, Nov. 2009The neonate may also be adversely affected by maternalhypotension and reduced uteroplacental perfusion. In mostinstances, however, maternal hypotension of short duration isassociated with transient fetal carbon dioxide retention and isof limited clinical consequence.
  7. 7. Maternal haemodynamic changes during spinal anaesthesia for caesarean section Eldrid Langesæter, Current Op in Anesth, 2011, 24:242–248 Key points1. The typical haemodynamic effects of spinal anaesthesia in healthy pregnant women are a decrease in systemic vascular resistance and a compensatory increase in cardiac output; phenylephrine is, thus, the first-line vasopressor.2. The rarer presentation of hypotension and bradycardia should be treated with ephedrine and/or anticholinergics.
  8. 8. SUMMARY Spinal is commonly for caesarean. Advantages for the mother: remaining awake for the birth, no risks of General and facilitating POP pain relief. The commonest side-effect of spinal is hypotension, which is often accompanied by nausea or vomiting, or both. Severe hypotension poses serious risks to mother (loss of consciousness) and baby (lack of O2 and brain damage). The review found that no single method completely prevents hypotension, but the incidence is reduced by administering IV fluids, ephedrine or phenylephrine, and by compressing the legs with bandages, stockings or inflatable boots.
  9. 9. Conclusion: There is not one accepted definition of hypotension in the scientificliterature. The incidence of hypotension varies depending on the chosendefinition. Even minor changes of the definition cause major differences inthe frequency of hypotension.
  10. 10. 1. Incidencia de hipotensión: 50% a 80%.2. La simpatectomía causa vasodilatación y consecuente disminución de RVS.3. La presión baja disminuye el flujo sanguíneo en la art. uterina, lo que indi-rectamente afecta al feto. Si persiste puede ocurrir acidosis fetal. (10 min de Flujo - 65% = Acidosis).
  11. 11. Clin Chest Med32 (2011) 15–19
  12. 12. Intrapartum Fetal Pulse Oximetry: Clinical Application Vol 55(3), March 2000, pp 173-183The normal range of fetal arterial oxygen saturation(FSpO2), 30 to 70%, lies in the middle of the O2dissociation curve, so that small changes in pH or PO2cause large changes in FSpO2
  13. 13. Curva de saturación de la oxihe- moglobina para el feto (A) y adulto (B)Patrón circulatorio en el útero
  14. 14. DETERMINANTS OF FETAL OXYGENATIONThe fetus has made four major adaptations to compensate for the low PO2.1. The rate of perfusion of fetal organs in sheep preparations is 2.5-fold greater than blood flow to the same organs in the adult.2. Fetal hemoglobin has a higher affinity for oxygen than adult hemoglobin.3. Third, fetal hemoglobin levels are increased over adult values.4. A system of vascular shunts and streaming effects directs oxygenated blood to high-priority tissue in the liver, heart, and brain and guides deoxygenated blood back to the placenta. Adkinson: Middletons Allergy: Principles and Practice, 7th ed.
  15. 15. Sir Joseph Barcroft first drew a close analogy between the low partial pressureof oxygen of the fetus in utero and that which would be found in humans at analtitude of 30,000 to 33,000 ft on Mt. Everest when he observed, ‘‘The fetus thengrows in an environment the oxygen concentration of which is falling all thetime—an uphill business you may say. True indeed, for is it not the problem ofEverest, the maintenance of the organism in the atmosphere becomingprogressively rarer?’’ He later neatly summarized this concept with the phrase,‘‘Mt. Everest in utero.’’ 1. Barcroft J. The conditions of foetal respiration. Lancet 1933;222(5749):1021–4. 2. Barcroft J. Researches in prenatal life. London: 1946. Clin Perinatol, 36 (2009) 655–672
  16. 16. In conclusion, we found that labor CSE in patients with cervicaldilation >3 cm, ruptured membranes, and fetal descent, does notsignificantly alter fetal oxygenation. The impact of labor CSE onFSpO2 is minimal and appears similar to epidural analgesia.
  17. 17. Pathophysiology of Fetal Growth Restriction: EXTRÍNSICASImplications for Diagnosis • Tabaquismo and Surveillance • Alcoholismo Ahmet Alexander Baschat, MD • Drogadicción • Infecciones virales MATERNAS FAC. PLACENTARIOS • Hipertensión DESÓRDENES EN EL • Mosaicismo • Pre-eclampsia DESARROLLO • Implantación anormal • Sx. antifosfolipidos FETAL • Útero anormal • Trombofilia • Abruptio plac. crónico FETAL CAUSAS Y • Trisomías cromosómicasCONDICIONES • Desórdenes Mendelianos • Alt. Anatómicas congénitas Vol 59, Number 8 • Otros Síndromes OBSTETRICAL ANDGYNECOLOGICAL SURVEY
  18. 18. Metabolic adaptation at birth Ward Platt M AUG-2005; 10(4): 341-50 Seminars in Fetal & Neonatal Medicine Newcastle Neonatal Services, Royal Victoria Infirmary, Department of Child Health, Queen Victoria Road, Newcastle upon Tyne NE1 4 LP, UK. Abstract:The neonate must make a transition from the assured continuoustransplacental supply of glucose to a variable fat-based fueleconomy. The normal infant born at term accomplishes thistransition through a series of well-coordinated metabolic andhormonal adaptive changes.
  20. 20. Bearing in mind that the intrauterine PO2 amounts to only 25–30mmHg in contrastto the adult 90–100 mmHg, this would enable the fetus to maintain a similarmetabolic rate to the mother despite a much lower PO2 and, thus, would exactlycorrespond to the metabolic adaptation of fetal mammals Metabolic adaptation to hypoxia: cost and benefit of being small Dominique Singer Respiratory Physiology & Neurobiology 141 (2004) 215–228
  21. 21. Foca de Weddell
  22. 22. Nutrientes y Alteración en Hipercapnea Oxígeno Intercambio gas Fetal Respuesta al Hipoxemia Acidosis estrés Fetal RespiratoriaDisminución del Crecimiento Metabolismo Anaeróbico Bradicardia e Hipotensión Perfusión a AcidosisÓrganos vitales LácticaSufrimiento de Muerte Fetal Órganos Intraútero
  23. 23. Perinatal asphyxia pathophysiology in pig and human: A review Animal Reproduction Science xxx (2005) xxx–xxx María Alonso-Spilsbury, Daniel Mota-Rojas
  24. 24. Intrapartum Assessment of the Fetus: Historicaland Evidence-Based PracticeGary A. Dildy III, M Obstet Gynecol Clin N Am 32 (2005) 255– 271
  25. 25. The Timing of BirthA hormone unexpectedly found in the human placenta turns out to influence the timing of delivery. This and related findings could yield much needed ways to prevent premature labor Scientific American March 1999
  26. 26. Endocrinology of Parturition Victoria Snegovskikh, MD Endocrinol Metab Clin N Am 35 (2006) 173–191
  27. 27. Endocrinology of Parturition Victoria Snegovskikh, MD Endocrinol Metab Clin N Am 35 (2006) 173–191
  28. 28. CVCI CA Resistencia Tono Hb miometral: Viscocidad SO2 Hb Vascular sanguínea • tono • contracciones Hipotensión SistémicaPr. Vena . Uterina Pr. Art . Uterina Resistencia Intrínsica Presión Resistencia Perfusión Vascular Uterina Uterina Pr y Flujo Sanguíneo Uterino Contenido de O2 Aporte Uterino: Nutientes y O2
  30. 30. MONITOREO:• Tococardiografía, pH Fetal• Lactato Fetal, Pulso Oximetría FetalOPTIMIZAR O2 MATERNO• Administración de O2 a Pr. mormal• O2 a Presión PositivaOPTIMIZAR PERF. PLACENTARIA• Adecuar / discontinuar Occitocina,• Tocolíticos: disminuir hiperestimu- lación
  31. 31. • Efedrina: cruza la placenta y al aumentar el metabolismo fetal puede producir acidosis fetal y taquicardia materno/fetal• Fenilefrina: no altera la perfusión, ni genera acidosis, pero bradicardiza al feto y la madre. COMBINACIÓN EFECTIVA: FENILEFRINA + EFEDRINA + CO- HIDRATACIÓN + MANIOBRAS FÍSICAS
  32. 32. OPTIMIZAR PERFUSIÓN UTERINA:• Lateralización materna• Vasopresor + Carga de cristaloideMEJORAR FLUJO UMBILICAL:• Amnio-infusión• Cambio posicional a la madrePARTO:• Evitar Prematurez, y trabajo de Parto• Anestesia Regional para Cesárea
  33. 33. Posición y Circulación UterinaIntrauterine Resuscitation: Active management of Fetal Distress JA Thurlow Int. J of Obst Anesthesia 2002, 11, 105-116
  34. 34. Efficacy of intrauterine resuscitation techniques in improving fetal oxygen status during labor Simpson KR - Obstet Gynecol - 01-JUN-2005; 105(6) Intrauterine Resuscitation: Active management of Fetal Distress JA Thurlow, Int. J of Obst Anesthesia 2002, 11, 105-116
  35. 35. Birth Asphyxia and Cerebral Palsy Jeffrey P. Phelan, MD Clin Perinatol 32 (2005) 61– 76
  36. 36. Do hyperoxaemia and hypocapnia add to the risk of brain injury after intrapartum asphyxia? G Klinger, J Beyene, P Shah, M Perlman Arch Dis Child Fetal Neonatal Ed 2005;90 ORIGINAL ARTICLE Conclusions:Severe hyperoxaemia and severehypocapnia were associated with adverseoutcome in infants with post asphyxial HIE.During the first hours of life, oxygensupplementation and ventilation should berigorously controlled. Current North American neonatal resuscitation guidelines recommend the use of 100% inspired oxygen, whereas British guidelines suggest that ‘‘it may be more appropriate to use an inspired oxygen concentration of 40% initially and increase this if required’’.
  37. 37. Intrauterine resuscitation during labor: should maternal oxygen administration be a first-line measure? Simpson KR - Semin Fetal Neonatal Med, 01-DEC-2008; 13(6): 362-7Recent evidence suggests potential risks to the mother and fetus ornewborn. Even small increases in maternal and fetal Po2 as a resultof maternal O2 administration can produce O2 free radical activity inmothers and fetuses. The potential long-term effects are unknown.Caution should be exercised when considering maternal O2administration as a first-line intrauterine resuscitation measure
  38. 38. Optimal Oxygen Saturation for Preterm Babies Do We Really Know? The James Cook University Hospital, Middlesbrough, UK Biol Neonate, Review, Win Tin, 2004;85:319-325 O2 is the most commonly used drug in neonatal units as an integral part of respiratory support. History of Neonatal Resuscitation - Part 2: Oxygen and Other Drugs Michael Obladen Dept. of Neonatology, Charité Un. Medicine, Berlin, Germany Neonatology 2009;95:91-96O2 was used in neonatal resuscitation from 1780, within 5 years of its detection. It rapidly gained general acceptance and infiltrated delivery rooms and, a century later, neonatal special care units.After 217 years without scientific evidence, the use of O2 for neonatal resuscitation has recently been questioned.
  39. 39. The Indian Anaesthetists, October 2004(1), Dr. Sunanda Gupta MD SUPPLEMENTARY OXYGEN ADMINISTRATION DURING REGIONAL ANAESTHESIA FOR LSCS – IS IT JUSTIFIED?1. There be no significant increase in the maternal – fetal O2 transfer rate when O2 tension is raised on the maternal side, since with the increase in O2 tension of the perfusing blood, there is probably a concomitant vasoconstriction which negates any positive effects that might be expected as a result of increasing the maternal-fetal O2 gradient.2. Breathing high FiO2 modestly increased fetal oxygenation, but caused a concomitant increase in O2 Free Radical activity in both mother and fetus.
  40. 40. Air versus oxygen for resuscitation of infants at birth Tan A, Schulze A, ODonnell CPF, Davis PG. Last Update: 09/12/2006 NICHD Cochrane Neonatal Home Page Introduction to Neonatal Systematic Reviews ConclusiónPor lo tanto, sobre la base de la evidencia actualmentedisponible, si se elige el aire ambiental como gas inicial para la reanimación, se debe seguir garantizando la disponibilidad de O2 complementario.
  41. 41. Resuscitation of Newborn Infants with 21% or 100% Oxygen: An Updated Systematic Review and Meta-Analysis Systematic Review and Meta-Analysis Vol. 94, No. 3, 2008, Ola Didrik Saugstad, M. Vento Conclusions: Recent Advances in Neonatal Medicine There is a significant reduction in the risk of neonatal mortality and a International Symposium the risk of An trend towards a reduction in Honoring Prof. Ola Didrik Saugstad severe hypoxic ischemic encephalopathy in newborns Würzburg, Oct 2–4, 2008 resuscitated with 21% O2.…coining the term ‘the oxygen radical disease of the newborn’ in whichhe speculated that retinopathy of prematurity, bronchopulmonarydysplasia, necrotizing enterocolitis, patent ductus arteriosus andperiventricular leukomalacia are different facets of one disease…
  42. 42. The human fetus develops in a profoundly hypoxic environment. Thus, the foundations of our physiology are built in the most hypoxic conditions that we are ever likely to experience: the womb.This magnitude of exposure to hypoxia in utero is rarely experienced in adultlife, with few exceptions, including severe pathophysiology in critical illness andenvironmental hypobaric hypoxia at high altitude. Indeed, the lowest recordedlevels of arterial oxygen in adult humans are similar to those of a fetus and wererecorded just below the highest attainable elevation on the Earth’s surface: thesummit of Mount Everest. We propose that the hypoxic intrauterine environmentexerts a profound effect on human tolerance to hypoxia.Cellular mechanisms that facilitate fetal well-being may be amenable tomanipulation in adults to promote survival advantage in severe hypoxemicstress.
  43. 43. Concepts in hypoxia Therapy for hypoxemic reborn critically ill adults:Daniel S Martin, Critical Care, potential therapeutic 2010, 14:315 targets
  44. 44. Permissive Hypoxemia Is It Time To Change Our Approach? Mohamed Abdelsalam, MD, CHEST / 129 / 1 / JAN,, 2002 2006 Goal-Directed Therapy for Severely Hypoxic Patients With ARDS: Permissive Hypoxemia M. Abdelsalam MD, RESPIRATORY CARE, Nov, 2010 vol 55 No 11Cuáles son los riesgos potenciales de la Hipoxemia Permisiva?, Se tolera igual en todos los órganos y sistemas?Órganos diferentes tienen tolerancia diferente a la hipoxemia. Porejemplo un cerebro sano, puede en general, tolerar mejor lahipoxemia, a condición de que la perfusión cerebral se mantenga. En general, la estrategia de hipoxemia permisiva significa mantener el O2 entre 82 y 88% de SaO2