8/11/2019 Neonatal Physiology Revised 5-12-14!1!3

1/37

Neonatal Physiology

Tulane Pediatric Surgery

8/11/2019 Neonatal Physiology Revised 5-12-14!1!3

2/37

Topics

Fluids and Electrolytes

Cardiopulmonary

Temperature Regulation

Jaundice

Host Defenses

Surgical Stress Response

8/11/2019 Neonatal Physiology Revised 5-12-14!1!3

3/37

Fluids and Electrolytes

Glucose

Placental

Glycogen Storage

Gluconeogenesis

Hypoglycemia

SGA

Surgical Pts

Hyperglycemia

8/11/2019 Neonatal Physiology Revised 5-12-14!1!3

4/37

Fluids and Electrolytes

Calcium

Placental Diffusion

75% third trimester

Limited Stores

Renal Immaturity

Hypoparathyroidism

Citrate can bind and decrease Ca

8/11/2019 Neonatal Physiology Revised 5-12-14!1!3

5/37

Fluids and Electrolytes

Magnesium

Associated with Calcium

Growth Retardation

Maternal Diabetes

Exchange Transfusions

8/11/2019 Neonatal Physiology Revised 5-12-14!1!3

6/37

Fluids and Electrolytes

Blood Volume

Highest Delivery

Cord Clamping

Polycythemia

Hct>65

Diabetes

Toxemia SGA

Partial Exchange

8/11/2019 Neonatal Physiology Revised 5-12-14!1!3

7/37

Fluids and Electrolytes

Hemolytic Anemia

Maternal Antibodies

Direct Coombs Rh most common

Congenital Infections

SS Dz

8/11/2019 Neonatal Physiology Revised 5-12-14!1!3

8/37

Fluids and Electrolytes

Anemia

Premature Infants

Erythropoeitin

8/11/2019 Neonatal Physiology Revised 5-12-14!1!3

9/37

Fluids and Electrolytes

Hemoglobin

80% Fetal

Erythropoeisis 2-3 months P50 Adult Hgb 27 mmHg

P50 Fetal Hgb 8 mmHg

8/11/2019 Neonatal Physiology Revised 5-12-14!1!3

10/37

Jaundice

Hemolysis

Glucoronyl Transferase

Unconjugated Hyperbilirubinemia

Peaks 3rdDay 6-7mg/dl

Resolves Day 10

8/11/2019 Neonatal Physiology Revised 5-12-14!1!3

11/37

Jaundice

Non Physiologic

Breast Feeding

Hemolytic Disease

Hypothyroid

Pyloric Stenosis

Crigler-Najar

Extravascular Blood

Biliary Atresia

Hepatitis

8/11/2019 Neonatal Physiology Revised 5-12-14!1!3

12/37

Jaundice

Non-Physiologic

Conjugated > 2mg/dl

Rises > 5mg/dl/day

Born Jaundiced

Doesnt Resolve

8/11/2019 Neonatal Physiology Revised 5-12-14!1!3

13/37

Temperature Regulation

Evaporation

Conduction

Convection

Radiation

8/11/2019 Neonatal Physiology Revised 5-12-14!1!3

14/37

Temperature Regulation

Humidified Environments

Incubator

Ventilator Circuits

Radiant Warmers

Dry Heat

Increased insensible losses

Clothes/Blankets

8/11/2019 Neonatal Physiology Revised 5-12-14!1!3

15/37

Temperature Regulation

Hypothermia

Hypoglycemia

Vasoconstriction

Coagulopathy

Emergence from Anesthesia

8/11/2019 Neonatal Physiology Revised 5-12-14!1!3

16/37

Renal Function

Low GFR

Better at 2 weeks

Normal at 1-2 years

Decreased Concentrating Ability

600mOsm

Insensitive to ADH

8/11/2019 Neonatal Physiology Revised 5-12-14!1!3

17/37

Cardiopulmonary

Fetal Circulation

Right to Left Shunts

Foramen Ovale

Ductus Arteriosus

Hypoxemia

Hypercarbia

Acidosis

8/11/2019 Neonatal Physiology Revised 5-12-14!1!3

18/37

Cardiopulmonary

Persistent Fetal Circulation

Sepsis

Meconium Aspiration

Congenital Diaphragmatic Hernia

Idiopathic

Treatment

Ventilation Pharmacology

ECMO

8/11/2019 Neonatal Physiology Revised 5-12-14!1!3

19/37

Cardiopulmonary

Surfactant Deficiency

Premature

Alveolar Stability

Exogenous Administration

8/11/2019 Neonatal Physiology Revised 5-12-14!1!3

20/37

Host Defenses

Cellular Immunity

WBCs

Phagocytosis

Adherence

Killing

Decreased Stores

Poor Stem Cell Production

8/11/2019 Neonatal Physiology Revised 5-12-14!1!3

21/37

Host Defenses

Immunoglobulins

IgG crosses the placenta

Poor Response to Antigen Challenge

IgA and IgM

No type specific Antibodies

Decreased Complement System Function

Increased Mortality with Pyogenic BacterialInfections

8/11/2019 Neonatal Physiology Revised 5-12-14!1!3

22/37

Surgical Stress Response

Initially Poorly Understood

Crude Monitoring

Few Outcome Studies

Myths

Anesthetics Unsafe/Not Approved

Pain

Could Anesthesia Blunt Surgical Stress

Response?

8/11/2019 Neonatal Physiology Revised 5-12-14!1!3

23/37

Surgical Stress Response

Measured Catecholamines, Insulin, Cortisol.

Adult Physiology

Levels Decreased when Anesthesia

Administered

8/11/2019 Neonatal Physiology Revised 5-12-14!1!3

24/37

8/11/2019 Neonatal Physiology Revised 5-12-14!1!3

25/37

8/11/2019 Neonatal Physiology Revised 5-12-14!1!3

26/37

8/11/2019 Neonatal Physiology Revised 5-12-14!1!3

27/37

8/11/2019 Neonatal Physiology Revised 5-12-14!1!3

28/37

8/11/2019 Neonatal Physiology Revised 5-12-14!1!3

29/37

8/11/2019 Neonatal Physiology Revised 5-12-14!1!3

30/37

8/11/2019 Neonatal Physiology Revised 5-12-14!1!3

31/37

8/11/2019 Neonatal Physiology Revised 5-12-14!1!3

32/37

8/11/2019 Neonatal Physiology Revised 5-12-14!1!3

33/37

8/11/2019 Neonatal Physiology Revised 5-12-14!1!3

34/37

8/11/2019 Neonatal Physiology Revised 5-12-14!1!3

35/37

8/11/2019 Neonatal Physiology Revised 5-12-14!1!3

36/37

8/11/2019 Neonatal Physiology Revised 5-12-14!1!3

37/37