What are the Neuro Changes of Pregnancy?
Decreased MAC, Epidural Space, and CSF
Engorged Epidural Veins
Increased LA Sensitivity
What are the Respiratory Changes of Pregnancy?
↑Minute Ventilation (50%)
Which of the following is decreased during Pregnancy?
A. Vital Capacity
B. Total Lung Capacity
C. Functional Residual Capacity
D. Dead Space
E. Airway Resistance
What Respiratory changes helps delivery of oxygen to fetus?
Increase of P50 Hemoglobin from 27 to 30 mmHg
What happens to the Respiratory Mucosa during Pregnancy?
Congestion d/t Vasodilation
Mucosal Engorgement = ↑Mallampati
What makes the mother prone to hypoxia during pregnancy?
↓FRC & ↑O2 Consumption
Preoxygenate & RSI w/ Cricoid Pressure
Why should Hyperventilation be avoided in Pregnancy during Anesthesia?
Low PaCO2 causes uterine vasoconstriction decreasing placental blood flow & left HgbO2 shift
What Intubation equipment should be available for Pregnant Patients?
Avoid Nasal Intubation
How is Oxygen Delivery optimized during Pregnancy?
Right HgbO2 Shift
↓PVR d/t Increased Progesterone
How is Plasma Volume affected by Pregnancy?
Increased Plasma Volume d/t Increased Renin
What are the different phases of changes in Cardiac Output during Labor?
- Latent Phase: ↑15%
- Active Phase: ↑30%
- Second Stage: ↑45%
- Postpartum: ↑80%
What are the CV changes during Pregnancy?
Blunted Adrenergic Response
↓Plasma Colloid Osmotic Pressure
What is Supine Hypotension Syndrome?
Hypotension, Pallor, N/V, and Diaphoresis when Preggos lie flat
What is the best position for Supine Hypotension Syndrome?
Left Lateral Uterine Tilt
How does the blood change in a pregnant patient?
Depressed Cell-Mediated Immunity
PT/PTT decreases by 20%
Which Coagulation Factors are Increased during Pregnancy?
1, 7, 8, 9, 10, 12
Which Coagulation Factors are Decreased during Pregnancy?
11 & 13
Which Coagulation Factors are uneffected by Pregnancy?
2 & 5
What are the Renal Changes during Pregnancy?
↑Blood Flow & Filtration
↓BUN & Creat
Mild Glycosuria & Proteinuria
How does Pregnacy affect the Gastroesophageal Sphincter?
Reduced Competence & Tone
What are the GI Changes during Pregnancy might increase Aspiration Risk?
Increased Acid Secretion & Gastric Fluid
How is the Gallbladder affected by Pregnancy?
Sluggish & Gallstones d/t decreased CCK
How is the Liver affected by Pregnancy?
(No effect on Sux Duration)
How does Pregnancy affect Blood Glucose?
Insulin Resistance = ↑Blood Glucose transfer to Fetus
What are the methods of transfer accross the Placenta?
How long can the Fetus live without Oxygen?
What is the transfer of Oxygen to the Fetus dependent on?
Maternal Uterine Blood Flow vs. Fetal Umbilical Blood Flow
How much Oxygen is stored and consumed by the Fetus?
Stored O2: 42 mL
Consumed O2: 21 mL/min
How does the Fetus compensate for the Placental PaO2 of 40 mmHg?
Mom: Right HgbO2 Shift
Fetus: Left HgbO2 Shift & More Hgb
How is CO2 transfered across the Placenta?
Fetal Hgb has lower CO2 affinity than Mom
Normal Uterine blood flow is 50 mL/min. How much is that increased during Pregnancy?
600-700 mL/min (10% of Cardiac Output)
80% of that goes to Placenta; the rest to Myometrium
What factors affect Uterine Blood Flow (UBF)?
What anesthetic agents and drugs can decrease Uterine Blood flow?
Gases > 1 MAC
How does Ketamine, Opioids, and N2O affect Uterine Blood FLow?
Little to No Effect
How does high serum Local Anesthetics affect the Uterus?
Uterine Vasoconstriction, but Neuraxial Analgesia can reduce Vasoconstriction
What happens to infant's heart & lungs at birth?
Oxygen filling lungs ↓Pulm. Vascular Resistance
↑LAP closes Foramen Ovale
↑Oxygen Tension closes Ductus
What can happen if the Ductus remains open w/ Hypoxia or Acidosis?
Downward Spiral of Hypoxia & Acidosis d/t increase R-to-L Shunt
When does normal Labor begin?
40 +/- 2 weeks after LMP
What happens in the 1st Stage of Labor?
Latent Phase: Minor Dilation 2-4cm & Infrequent Contractions
Active Phase: Progressive Dilation to 10cm & Regular Contractions q3-5 min
When is the 2nd Stage of Labor?
From Complete Dilation to Delivery
What is the 3rd Stage of Labor?
From Infant Delivery to Placenta Delivery
What is happening here?
What is happening here?
Compression of Vessels
What is happening here?
Umbilical Cord Compression
What is the most common cause of Materal Palsy?
Cephalopelvic Disproportion - causes lumbosacral trunk compression
What are the complications of Neuraxial Blocks?
Postdural Puncture Headache (PDPH)
High/Total Spinal Anesthesia
What are the types of Nerve Injuries that can happen from Neuraxial Blocks?
Epidural Hematoma & Abscess
Chemical Nerve Injury
What kind of patients get Epidural Hematomas?
Patients w/ Coagulopathy during block placement or catether removal
What must the coags be for a patient with Pregnacy-Induced HTN to get a Neuraxial Block?
Platelet > 100K & Stable
IV Analgesia if on Heparin
What are the Neuraxial Block guidelines for a patient on Heparin?
- Avoid block for 24 hr if therapuetic
- Avoid block for 12 hr if prophylactic
- Remove Catheter 12 hr after last dose
- Dont give Heparin until 2-4 hr after block placed
- Avoid concurrent NSAIDs
- Alter Dose or Monitor Anti-Xa
What are the Signs and Symptoms of an Epidural Hematoma?
Get CT or MRI
Must be decompressed w/in 6 hrs
What are some sources of an Epidural Abscess?
Colonization of Iodine Bottles or Epidural Catheters
When would you see symptoms of an Epidural Abscess?
Pain & Loss of Fxn
What is the Treatment for an Epidural Abscess?
Abx or Laminectomy w/in 6-12 hrs
What are the Symptoms of an Epidural Abscess?
Back pain w/ Flexion
What makes the Epidural Space resistant to Toxicity?
Vascularity & Intact Membrane
What are Transient Neurological Symptoms (TNS)?
Pain & Dysesthesia in butt & legs after Lidocaine Subarachnoid Block & Lithotomy Position
How can Needle Trauma happen?
Pain from hitting cord w/ needle at the conus (T12-L3)
OK if withdrawn immediately
Dont do regionals on sleeping patients
How can the Lithotomy position cause Nerve Injury
Compresses Common Peroneal, Femoral, and Obturator Nerves
Recovery from days to years depending on severity
What is the onset and duration of Post-Dural Puncture/Spinal Headaches?
12- 48 hrs after dura puncture & lasts days to weeks
How does a Post-Dural Puncture cause Headache?
Loss of CSF volume as little a 20cc
Intracranial Sagging & Stretching of Pain Tissues
What are Post-Dural Puncture Headache Risk Factors?
Big Sharp Needle
Hx of PDPH or Migraine
What are Post-Dural Puncture Headache Risk Factors when using an Epidural Needle?
What is the chance of a Post-Dural Puncture Headache using a 16-18 ga. Epidural?
What is the chance of a Post-Dural Puncture Headache using a 22 ga. Quincke vs. a 25 ga. Quincke?
22 ga. : 30-50%
25 ga. : 8-10%
What is the chance of a Post-Dura Puncture Headache using a 24 ga. Sprotte?
What is the chance of a Post-Dura Puncture Headache using a 25 ga. Whitacre?
What are the best type of needles to use to avoid Post-Dura Puncture Headaches?
Pencil Point needle w/ Side Hole
Pushes Dura Fibers instead of cutting
What is the Hallmark of a Post-Dura Puncture Headache?
Continuous head pain when sitting or standing fully relieved by recumbence
What is the most common cause of PeriOperative Headaches?
What is a Pneumocephalus Headache?
Instant headache w/ short duration when air injects intrathecal
What is a Cortical Vein Thrombosis Headache?
Throbbing head ache not relieved by bed rest w/ possible Seizure
What should you look for if a Subarachnoid Hemorrhage is suspected?
Focal Neurological Deficits
What are Arnold-Chiari related Subdural Hematomas?
CSF leak causes lower brainstem to move down causing headaches, focal neuro signs, and blood vessel tears causing a subdural hematoma
What can happen if Post-Dura Puncture Headaches are left untreated?
Coning & Brainstem Death
What are the Non-Invasive Treatments for PDPH?
What is the Definitive Treatment for PDPH?
Epidural Blood Patch - Inject pt's own blood into epidural space
Inject slowly until headache stops
Repeat blood patches increase success to 90%
What are the risks for Epidural Blood Patches?
Same as epidural, but with more chance of backache
How are Prophylactic Epidural Blood Patches given?
Thru Epidural Catheter
May result in Total Spinal
How do Epidural Blood Patches work?
Clotting factors in blood seal dura hole and compresses CSF
What are signs of a High or Total Spinal Anesthesia?
Aphonia - Cant Speak
What are some causes of a High or Total Spinal Anesthesia?
Migrated Epidural Catheter
Unrecognized Dural Puncture
Subarachnoid Block (SAB) after failed Epidural
What should be done once a Total Spinal is recognized?
- Left Uterine Displacement or Trendelenburg Position
- Early Resuscitation, Ventilation, and Circulatory Support
- Give Epinephrine
- Give Narcan (For Opioid)
- Monitor Mom & Baby Closely
- Maintain Sedation
What might be the cause of Hypoxia, Pulmonary Edema, and Bronchospams for a Pregnant Patient?
What are ways to prevent Aspiration in the Pregnant Patient?
What should be done if the Pregnant pt aspirates?
Intubate & Positive Pressure Ventilation
Use necessary amt of O2