Anesthesiology Information

Anesthesia for the Pregnant Patient Undergoing NonOB-Surgery Reference: Hawkins, JL. Anesthesia for the Pregnant Patient Undergoing NonOB -Surgery. ASA Refresher Course. 2001. Jeffrey Groom, MS, CRNA, ARNP FIU - Anesthesiology Nursing Program NGR 6992 Principles of Anesthesiology Nursing II

NonOB SURGERY for OB Patients
Annually, 1 - 2.5% of pregnant patients require surgical procedures
Annually, approximately 75,000 anesthetics are administered
Whether or not your facility does OB Service, you will likely see OB patients

NonOB SURGERY for OB Patients
Most patients have a fear of anesthesia.
Most OB patients have a profound fear (concern) about anesthesia.
Many will want to forego analgesia and/or sedation…..which may in the end do more harm than good.

NonOB SURGERY PROCEDURES
MOST COMMON PROCEDURES:
TRAUMA
APPENDICITIS
OVARIAN CYST
CHOLECYSTECTOMY
BREAST BIOPSY
ABDOMINAL LAPAROSCOPIC PROCEDURES
CERVICAL CERCLAGE

SURGICAL PROCEDURES
LESS COMMON PROCEDURES
NEUROSURGICAL PROCEDURES
CARDIAC SURGERY
TRANSPLANT
PHEOCHROMOCYTOMAS
UROLOGICAL PROCEDURES
(Extracorporeal shock-wave lithotripsy is absolutely contraindicated)

Fetal Surgery
Performed in a few major centers
Major problem is postoperative preterm labor
Tocolytics: Preoperative Indomethacin and perioperative magnesium sulfate
High dose inhalational anesthesia for anesthetizing mother and fetus and provide uterine relaxation

RISK AND OUTCOME
RISK OF FETAL MORBIDITY RISES
CONGENITAL MALFORMATIONS DO NOT CORRELATE WITH ANESTHESIA EXPOSURE
INCREASE IN LOW BIRTH WEIGHT
RISK OF EARLY PERINATAL DEATH
INCREASE IN SPONTANEOUS AB

ANESTHESIA MANAGEMENT ISSUES IN PREGNANCY
ALTERATIONS IN MATERNAL PHYSIOLOGY
POSSIBLE TERATOGENIC EFFECTS
MAINTENANCE OF UTERINE PERFUSION AND EFFECTS OF ANESTHESIA ON FETUS
PREVENTION OF PREMATURE LABOR

Management Objective
Maintain:
maternal oxygenation,
cardiac output,
oxygen delivery, and
uterine blood flow

Blood Flow to Uterus

PHYSIOLOGIC CHANGES OF PREGNANCY

Late Gestation and Anesthesia Risks
Intubation difficulties with or without gastric acid aspiration
Unrecognized esophageal intubation
High or complete spinal block during regional anesthesia
Unintended deep inhalational anesthesia

ANESTHETICS AND FETUS
RISK CHANGES WITH GESTATIONAL AGE
CONCEPTION TO DAY 13, ADVERSE REACTIONS USUALLY RESULT IN DEATH
ORGANOGENESIS DAY 13 TO 90, MOST VULNERABLE
AFTER 13 WEEKS LESS DEVELOPMENTAL RISK
BY 3 rd TRIMESTER, RISK IS GREATEST FOR PRETERM LABOR

Changes in Risk Throughout Gestation
Early gestation - direct fetal effects mainly toxicity
Thalidomide Babies
Late gestation - maternal effects that indirectly produce fetal injury
Cerebral palsy induced by profound maternal hypoxia or hypotension near birth

Fetal Safety: Developmental Alterations and Anesthesia
Virtually all anesthetic agents given to the mother are rapidly shared with the unborn child.
The notable exception to this statement is paralytic agents which cross the placenta with difficulty because they are quaternary ammonium salts.

Risk Classification System
The Food and Drug Administration (FDA) 1980
Drug Use in Pregnancy and Lactation
Drug Facts and Comparisons
Physicians Desk Reference

U.S. Food and Drug Administration Classification of Teratogenic Drug Risk Adapted from Federal Register(1979) Contraindicated in Pregnancy. X Positive human evidence of fetal risk. D Risk cannot be ruled out. C No evidence of risk in humans. Either animal studies show no fetal risk or animal studies show risk but human studies do not show risk B Controlled studies show no risk. Well controlled human studies failed to demonstrate risk to fetus A Description of Risk Category

TERATOGENICITY
TIMING OF ADMINISTRATION
INDIVIDUAL SENSITIVITY TO THE AGENT
THE THRESHOLD AMOUNT OF EXPOSURE
NATURALLY OCCURING INCIDENCE OF CONGENITAL ANOMALIES

DOCUMENTED TERATOGENS
ACE INHIBITORS
ALCOHOL
ANDROGENS
ANTITHYROID
CHEMO-DRUGS
COCAINE
COUMADIN
DIETHYLSTIBESTEROL
LEAD
LITHIUM
MERCURY
PHENYTOIN
STREPTOMYCIN
THALIDOMIDE
TRIMETHADIONE
VALPROIC ACID

MEDICAL & SOCIAL FACTORS
DIABETIC MOTHERS
DRUG ABUSE - MOTHER & FATHER
GENETIC PREDISPOSITION
HYPOXIA
EXTREMES IN TEMPERATURE
ENVIRONMENTAL HAZARDS

FDA ratings
DRUG CATEGORY
Induction agents
Thiopental C
Methohexital B
Ketamine C
Etomidate C
Propofol B

Categories
Inhaled Agents
Halothane C
Enflurane B
Isoflurane C
Desflurane B
Sevoflurane B

Categories
Local Anesthetics
2-Chloroprocaine C
Tetracaine C
Bupivacaine C
Lidocaine B
Ropivacaine B

NITROUS OXIDE
CONTROVERSIAL
SMALL ANIMAL STUDIES AND DNA SYNTHESIS
N20 - ADRENERGIC TONE -VASOCONSTRICTION
TERATOGENICITY HAS NOT BEEN DEMONSTRATED IN HUMANS
CATEGORY X ?

BENZODIAZEPINES
CLEFT PALATE AND EXPOSURE TO DIAZEPAM IN FIRST TRIMESTER
LACK OF DATA
STILL CLASSIFIED AS A CATEGORY D AGENT
USE OR NOT
PDR

FETAL OUTCOME AFTER SURGERY
NO ANESTHETIC AGENTS EXCEPT COCAINE IS TERATOGENIC
HOWEVER
AVOID HYPOXIA, HYPERCARBIA, AND HYPOTENSION,
ALL CAPABLE OF INDUCING MALFORMATIONS AND FETAL DEATH

PreAnesthesia Assessment and Risks vs. Benefits

PRE-ANESTHESIA ASSESSMENT
WOMEN OF REPRODUCTIVE AGE CHECK FOR POSSIBLE PREGNANCY
PATIENT INFORMATION AND RISK COUNSELING
POSTPONE ELECTIVE SURGERY UNTIL AFTER DELIVERY
POSTPONE NONELECTIVE SURGERY UNTIL SECOND TRIMESTER
NO ANESTHETIC TECHNIQUE CORRELATES WITH A BETTER OUTCOME
EDUCATE ON SIGNS OF PRETERM LABOR

TYPE OF ANESTHESIA IS DICTATED BY:
PHYSICAL & MENTAL CONDITION OF PATIENT
EXTENT OF PLANNED PROCEDURE
PERCEPTION THAT MAC > Regional > GETA IS SAFEST ORDER OF ANESTHESIA METHODS, NOT VALIDATED BY THE DATA
Type of Anesthesia

PREOPERATIVE TREATMENT
HISTORY AND PHYSICAL EXAM
AIRWAY ASSESSMENT
PATIENT RAPPORT
ALLEVIATE ANXIETY
ADVISE AS TO RISKS
OB CONSULTATION
PRE-OP MEDICATIONS

GENERAL GUIDELINES
ASPIRATION PRECAUTIONS
POSITIONING
MONITORING

Management Objective
Maintain:
maternal oxygenation,
cardiac output,
oxygen delivery, and
uterine blood flow

Risk Factors for Aspiration in Pregnancy
Compromised LES function
Higher intragastric pressure
Anatomic displacement of stomach
Decreased gastric emptying in labor
Potential for no NPO period
Potential for difficult intubation

Factors Known to Worsen Aspiration Syndrome
Solid material aspiration
Increased acidity of contents
Higher aspirated volume
Regardless of NPO status all pregnant patients are at risk for aspiration from 8 weeks gestation to 6-8 weeks postpartum!

Agents for aspiration prophylaxis
Ranitidine (Zantac) 50mg IV
Cimetidine 300 mg IV
Metoclopromide (Reglan) 10 mgIV
Oral sodium citrate( Bicitra)30cc po

MATERNAL POSITIONING
BEGINNING WITH SECOND TRIMESTER, AVOID SUPINE POSITION
USE LEFT UTERINE DISPLACEMENT

FETAL MONITORING
BECOMES PRACTICAL AFTER 16-24 WEEKS GESTATION
EQUIPMENT AND PERSONNEL MUST BE AVAILABLE
TRANSDUCER MUST NOT ENCROACH ON THE SURGICAL FIELD
THERAPEUTIC INTERVENTIONS?

FETAL MONITORNG
Loss of beat-to-beat variability is normal after anesthesia
Decelerations may indicate need for:
Increased oxygenation, increased BP
Decreased surgical retraction
Initiation of tocolytics
HOWEVER, MONITORING NEEDS TO BE ACCURATE AND PROPERLY INTERPRETED

INDUCTION AND MAINTENANCE
AVOID HYPOXIA
AVOID HYPOTENSION
AVOID HYPERTENSION
AVOID HYPER/HYPOCARBIA
AVOID HYPOGLYCEMIA
AVOID HYPO/HYPERTHERMIA

REGIONAL
Decrease dose by 1/3
Prehydrate
Treat hypotension with fluid & ephedrine
If not used operatively, consider regional for post-op pain management

PostOperative
Monitor VS and FHT
Treat preterm labor
Appropriate pain management
Increased risk for thromboembolism

Trauma
Leading cause of maternal death
Fetal death secondary to maternal death or abruptio placenta
Fetal Assessment – STAT Ultrasound
Maternal Evaluation – Shield fetus
STAT Post-mortum C-Section
Stabilize/Optimize mother – VD or CS at 9mo better than emergent CS at time of injury
Emergent C-Section:
Stable MOM – FETAL distress
Traumatic uterine rupture – Unstable MOM and FETUS
Gravid uterus interfering with MOM E-lap
Unsalvageable MOM with viable FETUS

Appendectomy and Adnexal Masses Most Common Surgery
Parturients undergoing appendectomy have an 18% incidence of postoperative pulmonary edema or ARDS
Risk Factors for development of pulmonary edema are:
Gestational age > 20 weeks
Preoperative respiratory rate over 24 /min
Preoperative temperature > 100.4°F
A fluid load (I>O) > 4 liters in the first 48 hours
Concomitant tocolytic usage
Conservative FLUIDS, consider CVP line

Laparotomy Versus Laparoscopic Surgery
Laparoscopy – most common 1 st trimester procedure
Reduced pain and limited fetal exposure to postoperative opioids
More economical
Better surgical view with limited manipulation of uterus
More rapid return to mobility, reducing risk of thrombophlebitis

CO 2 Pneumoperitoneum
Continuous FHR monitoring ?
Limit abdominal insufflation pressure to 15 to 20 mm Hg
Increase minute ventilation
If fetal compromise develops-check ABG
Convert to Open procedure

Cervical Cerclage
Cervical cerclage is the surgical intervention used to prevent second - trimester fetal loss from cervical incompetence.
An incompetent cervix is the result of weakness of cervical os caused by trauma, congenital or multiple pregnancies
Usually done between 12 and 26 weeks gestation

Contraindications to cervical cerclage
Bleeding
Active labor
Ruptured membranes
Cervical dilation > 4 cm
Intrauterine infection
Fetal abnormalities
Abruptio Placenta

SUMMARY <16-20 WEEKS GESTATION
POSTPONE UNTIL 2nd TRIMESTER, PRN
PRE-OP EVAL. BY OBSTETRICIAN
PRE-OP COUNSULING
NONPARTICULATE ANTACID
OXYGENATION,NORMOCARBIA, NORMOTENSION & NORMOGLYCEMIA
REGIONAL if possible
FOR GETA – WEIGH BENEFIT v RISK of N2O
DOCUMENT FHT’s BEFORE, DURING, AFTER

SUMMARY > 16-20 WEEKS GESTATION
COUNSUL PREOPERATIVELY
TOCOLYTIC AGENTS?
ASPIRATION PROPHYLAXIS
USE LEFT UTERINE DISPLACEMENT
OXYGENATION, NORMCARBIA, NORMOTENSION, & NORMOGLYCEMIA
USE FHR MONITORING & MONITOR FOR UTERINE CONTRACTIONS

QUESTIONS ?

http://www.webicina.com	66
http://www.slideshare.net	4
http://translate.googleusercontent.com	1

Anesthesiology Information

by MedicineAndHealth on Feb 04, 2009

Accessibility

Categories

Tags

Upload Details

Usage Rights

3 Embeds 71

Statistics

Anesthesiology Information — Presentation Transcript