Complications in OB anesthesia

Question 1

What is the most common cause of postpartum maternal palsy?

Answer 1

cephalopelvic disproportion which results in lumbosacral trunk compression as it crosses pelvic brim by the fetal head.

Question 2

Epidural hematoma

Answer 2

Rare complication of neuraxial blockade

Usually occur in patients with hemostatic abnormality or coagulopathy.

Can occur with block placement or catheter removal, so insertion and removal should only occur when coagulation function is normal.

Question 3

How long do you avoid neuraxial block if therapeutic anticoagulated?

Answer 3

24 hours

Question 4

How long do you avoid neuraxial block if prophylactically anticoagulated?

Answer 4

12 hours

Question 5

How long after the last dose do you remove the catheter?

Answer 5

12 hours

Question 6

How long after a block is placed or removed do you can you give hepain?

Answer 6

2-4 h

Question 7

Other considerations for LMWH and blocks

Answer 7

Avoid concurrent NSAIDs or anticoagulants.

Consider altering LWMH dose or monitoring anti-Xa activity.

Question 8

Signs and Symptoms of Epidural Hematoma

Answer 8

Bilateral leg weakness

Incontinence

Absent rectal sphincter tone

Back pain

If hematoma suspected pt must get a stat CT or MRI

Surgical decompression must occur w/in 6 hrs for full neurological recovery to occur

Question 9

Can bottles of 10% iodine become colonized after a single use?

Answer 9

yep

Question 10

epidural abcess

Answer 10

If an infection is present it takes 4-10 days for sx (usually pain; loss of function) to occur.

Treatment – antibiotics and laminectomy have 6-12 hr window before permanent damage.

Question 11

Presentation of epidural abscess

Answer 11

Severe back pain
Worse with flexion; sometimes with radiation

Exquisite local tenderness

Fever, malaise, meningitis-like headache with neck stiffness

Laboratory changes
Inc. WBC, inc. ESR, positive blood culture

Progression over hours-days to neuro deficit or osteomyelitis

Question 12

Epidural space is very resistant to toxicity because:

Answer 12

very vascular
Intact membrane between it and the subarachnoid space

Question 13

Transient Neurological Symptoms (TNS)

Answer 13

Pain and dysesthesia in buttocks, legs or calves that can follow SAB, resolves w/in 72 hrs

Most commonly caused by lidocaine spinals
Seems more associated w/ lithotomy position, high doses of concentrated lidocaine (~5%).

Question 14

Where is the conus?

Answer 14

Conus is at T12-L3

Question 15

Do you do a block on a sleeping patient?

Answer 15

do not do regional blocks on sleeping patients – they can’t tell you if there’s something happening/pain

Question 16

Lithotomy stirrups- compress the ____ ______ nerve
Lithotomy position- ______ nerve and ______ nerve

Answer 16

Lithotomy stirrups- compress the common peroneal nerve
Lithotomy position- femoral nerve and obturator nerve

Ranges from transient ischemic injury to axonal crush
Recovery 2-6 days if mild; to 2-3 years if severe

Question 17

Postpartum foot drop happens from compression of what?

Answer 17

Either common peroneal nerve from stirrups or brow compression of lumbosacral trunk

Question 18

Principal determinants of “spinal headache” are?

Answer 18

size of dural hole and type of needle used.

Throbbing, postural, variable distribution.

Onset is typically 12-48 hr. after dura puncture.

Duration is a few days to weeks.

Question 19

How much CSF is made per day?

Answer 19

Normal CSF volume is 150cc.

450 cc of CSF is made per day.

Acute loss of as little as 20 cc of CSF will produce headache symptoms, caused by sagging of intracranial contents and stretching of the pain sensitive tissues when the patient assumes an upright posture.

Question 20

What needle size has the highest risk for PDPH?

Answer 20

16-18 ga epidural – 75-80% chance of PDPH

22 ga Quincke – 30-50% chance of PDPH
25 ga Quincke – 8-10% chance of PDPH
24 ga Sprotte – 3-5% chance of PDPH
25 ga Whitacre – 1-2% chance of PDPH

Question 21

Are pencil point needles better than cutting needles?

Answer 21

Yes!

Pencil point needles significantly better than cutting tip needles because dura fibers are not cut but just pushed apart

Question 22

What is the hallmark of PDPH?

Answer 22

The hallmark of a PDPH is continuous head pain when patient sitting or standing that is completely or almost completely relieved by recumbence.

Question 23

Differential Diagnosis for PDPH

Answer 23

usually photophobia and headache

Question 24

Most common cause of perioperative headache

Answer 24

Caffeine withdrawal

Question 25

What can happen if you don’t treat PDPH?

Answer 25

Chronic headache
Permanent impairment
Convulsions d/t cerebral vasospasm
“Coning” and brainstem death

Question 26

What is definitive therapy for PDPH?

Answer 26

Epidural Blood Patch

Epidural space is identified and 15-20 cc of the patient’s own blood is injected (in strict aseptic manner) into the epidural space. Start slow and stop either when patient says headache is gone or they have a pressure sensation in the ears.
Resolution of the headache is nearly instant and sustained ~ 80% of the time. A repeat increases the success rate to about 90%.

Question 27

Aspiration of Gastric Contents

Answer 27

Accounts for 1/3 of anesthetic lawsuits in obstetric population

Suspect aspiration with:
Hypoxia
Pulmonary edema
Bronchospasm

Question 28

Prevention OF ASPIRATION

Answer 28

Cricoid Pressure

Fasting- Elective C/S patients should fast at least 6 hrs. even if regional planned, laboring patients can have limited amounts of clear liquids during labor- At all times the parturient is considered to have a full stomach!

Sodium Citrate works within minutes to raise gastric pH- lasts ~30 min

H2 blockers (famotidine, ranitidine): Take at least 30 min to work

Metoclopramide (Reglan): dopamine antagonist which acts on intestinal tract via release of acetylcholine, this increases gut motility and facilitates gastric emptying, requires 40-60 min.

Question 29

Management of Aspiration

Answer 29

Intubation and positive pressure ventilation w/ PEEP.

Use only enough O2 to maintain O2 saturation in the 90s (high FiO2 may exacerbate lung injury!!!!!)

Suction as much as possible from airway.

Rigid bronchoscopy only used when large food debris needs to be removed.

Prophylactic antibiotics are controversial, may be detrimental.

Prophylactic steroids have no role.

Lavage is not routinely recommended.

Patients may become hypovolemic through fluid shifts