AM&RICAN MEDICAL WOMEN'S ASSOCIATION

VOLUME I1 hlARCH 1956 NUMBER 3

Anesthesia for Vaginal Delivery

VIRGINIA LAPGAR, M.D.

  F THE CORRECT DRUG IS EMPLOYED, and if
there is no mismanagement of anesthesia,
I there is no relation of agents or techniques to
maternal or infant mortality. Also, if there is no
maternal respiratory or circulatory depression as
a result of the use of drugs for pain relief, the
condition of the infant at birth is unrelated to
the use of analgesia and anesthesia. The choice of
method of pain relief is made on the basis of medi-
cal problems existing in the mother, obstetric prob-

lems or the urgency of the moment.

Hypnosis is theoretically ideal but time-consum-
ing. Antepartum hypnotic sessions during the last
trimester are re~mmended or, if this is not possible,
thiopentone supplement may be necessary.
Prepared childbirth, consisting of lectures to
both parents, and exercises in relaxation for the
mother also is theoretically ideal, and is also time-
ansuming. In a recent series completed at Sloane
Hospital for Women, 134 clinic patients attended

&. Apgdr is Professor of Anesthesiology,
Co/urnbkt University, and Attending Anes-
thesiologist, Presbyterian Hospitdl, New

1 york, New York.

I

such classes and 95 percent delivered vaginally; ZO
percent received no medication at a11 during the first
stage of labor. For delivery of the infant, 6 per-
cent received no anesthesia of any kind, 9 percent
pudendal block, 26 percent caudal or spinal anes-
thesia, and 59 percent inhalation anesthesia. This
distribution of techniques is similar to the experi-
ence with several thousand women delivered va-
ginally without benefit of classes. Infants were
evaluated according to the method shown in Table
I. The condition of the infant at birth compared
favorably with 3,800 consecutive vaginal deliveries,
as seen in Table 11.
The drugs used in first stage of labor comprise
three groups: Barbiturates are indicated only for
apprehension, a symptom common to primiparas,
especially those with language difficulty or mini-
mal intelligence. Rarely was an intravenous bar-
biturate used to counteract overdosage of a drug
used for regional anesthesia. An opiate may be
given intramuscularly or intravenously when pain
becomes uncomfortable. Barbiturates are not in-
dicated for pain, nor opiates solely for apprehen-
sion. The selection of the opiate and its dose
should be made individually. It is our feeling that
50 mg. of demerolm repeated at intervals is a much
more satisfactory dose than 75 or 100 mg. If mor-
phine is chosen, a dose of 6 mg. is suggested. A
derivative of the belladonna group is often added,

$A.M.w.A.-M~RCH 1956

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JOURNAL OF THE AMERICAN MEDICAL WOMEN'S ASSOCIATION

          TABLE I
EVALUATION OF NEWBORN INFANT

        Method of Scoring
Sixty seconds after the complete birth of the infant
(disregarding the cord and placenta), the following
five objective signs are evaluated and each given a
score of 0, 1 or 2. A score of 10 indicates an infant
in the best possible condition.

SIGN 0 1 2

Heart rate Absent Slow Over 100

(Below 100)

             Irregular Crying
Muscle tone Limp Some flexion Active
                of extremities motion

Resonse to cath- None Grimace Cough or
eter in nostril sneeze
(tested after oro-
pharynx is clear

Color Blue Body pink Completely

Respiratory effort Absent Slow Good

Pale Extremities pink

blue

to counteract the tendency to vomit from a side
action of the opiate, and to add to the general se-
dation. Scopolamine 0.4 mg. is especially useful,
while atropine, though successful in depressing
nausea, causes a patient to be more alert. Amnesia
doses of scopolamine are not recommended because
of total lack of co-operation of the patient, and
extreme restlessness necessitating surgical planes of
anesthesia for delivery. In situations beyond the
control of the anesthetist, or in accidental over-
dosage of barbiturates or opiates, two new drugs
which counteract each of these groups of drugs
are under investigation. Nomorphine has been
used on the obstetric service to counteract opiate
depression only 30 times in three years. It produced
the expected response in 24 infants. Its action is
much more predictable and efficient if given to the
infant in the umbilical vein, 0.25 mg., rather than
to the mother before delivery.
Continuous caudal analgesia solves well the
problems of pain relief toward the end of the first
stage, and of the second stage. If the anatomy of
the caudal region feels completely mysterious, a
continuous lumbar epidural anesthesia is per-
formed by preference, without subjecting the
mother to traumatic attempts at caudal anesthesia.
With the first indication of a need for pain relief,
we prefer to give one dose of demerol and scopo-
lamine. As the effect of these drugs is wearing off,
a vinyl plastic catheter is inserted into the caudal

TABLE I1

P. C. B. Vaginal deliveries

No. of Infants 134 3,800

Scores 0-1-2       3% 5.1 %
Scores 3-4-5-6-7     21% 23.8%
Scores 8-9-1 0      76% 71.1%

canal through a 16 gauge needle so that the tip of
the catheter lies at about the second sacral seg-
ment. After a test dose of 5 cc. of the drug select-
ed, if no sensory or motor change takes place, 10
more cc. are added and the effects observed for
about ten minutes. Additional 10 cc. doses are ad-
ministered until pain relief is satisfactory. Any of
the drugs used for regional anesthesia may be
used for continuous caudal anesthesia, in appro-
priate concentrations. Our present preference is for
0.75 percent xylocainem with adrenalin 1 : 200,000 if
the maternal blood pressure is not over 130/@!
mm. Hg. If higher, adrenalin is omitted. The
signs of a successful caudal anesthesia are many,
the most important being pain relief from con-
tractions. This subjective sign does not necessarily
accompany any specific level of loss of sensation to
pinprick, sympathetic sign, or motor paresis. The
most reliable objective signs are those observed in
the rectal area, and paresis of the legs. Loss of tone
of gluteus minimus, absent anal skin reflex, loss
of tone of the anal sphincter, and inability to con-
tract it indicate the beginning of a successful cau-
dal anesthesia. If pain relief still is not present,
addition of more drug will effect this. If the anes-
thesia must be administered with speed, the air test
is omitted, as is the test dose, and the drug, 15 CC.,
is injected before the catheter is inserted. With
the concentration of xylocaine mentioned, it is d&-
cult to tell an accidental intrathecal injection which
gives a differential spinal anesthesia from a suc-
cessful caudal anesthesia. The real differential
diagnosis lies in the occurrence of a typical post-
spinal headache.

Continuous lumbar epidural anesthesia is ad-
ministered to the patient in the sitting position,
unless the patient is thin. The sitting position
makes the palpation of anatomic landmarks easier,
but does increase cerebrospinal fluid pressure in the
lumbar area, making it a little more likely that the
dura will be punctured. Several methods exist to
identify the epidural space. All except one depend
on the presence of negative pressure transmitted
from the thoracic area. Sucking in of a fluid level
in the needle; deflation of a small, inflated balloon
attached to the hub; and the springing in of the
stylet of the Macintosh needle are examples of the
first group. We still find the lessened resistance of
a smoothly riding piston of a 2 cc. syringe after
the needle has entered the epidural space, as corn-
pared with the resistance felt when the tip is in the
subflavian ligament, the most useful sign. If by
chance the tip has entered the subarachnoid space,
pulling back on the piston reveals the presence of
spinal fluid, which can be reinjected, and the
needle withdrawn until no fluid appears. With this

J.A.M.W.A.-VOL. 1 I I PIo. '

ANESTHESIA FOR VAGINAL DELIVERY 85

method, no spinal fluid is lost. With the methods
involving the removal of a stylet, the presence of
spinal Auid is all too obvious since it shoots out
the end of the needle to be lost on the drapes. A
Huber tip needle permits the downward placement
of the catheter, avoiding the embarrassing situa-
tion of having good anesthesia of the lumbar seg-
ments and none of the lower sacral segments.
Using the Huber tip needle facing caudally, in-
serting the catheter for several inches, and turning
up the head of the bed will usually assure good
sacral anesthesia.
Bilateral lumbar sympathetic block, maintained
by insertion of catheters, is satisfactory in some
hands, but another method is of course needed for
management of second stage and delivery.
Other blocks useful at the time of delivery are
local infiltration of the site of episiotomy, and pu-
dendal block performed by the transvaginal route.
Five to 10 CC. of one percent xylocaine placed
slightly posterior, medial, and inferior to the tip
of the ischial spine will give a prompt anesthesia
of adequate duraaon.

A single dose spinal anesthesia, popularly known
as saddle block, is eminently satisfactory for instru-
mental delivery. With the end of the delivery table
dropped a few inches, the patient is asked to as-
sume a relaxed sitting position. A small spinal
needle, 0.25 gauge, 2% inch, is inserted quickly
into an easily palpable lumbar interspace, without
skin wheal, and 3.0 to 4.5 mg. of 0.3 percent hy-
perbaric pontocaine*, or 2.5 to 3.75 mg. of hyper-
baric 0.25 percent nupercaine is injected between
contractions. The sitting position is maintained for
20 to 30 seconds. Intravenous ephedrine is rarely
needed to treat hypotension.

Many methods are available for general anes-
thesia, the success of which of course depends on
the availability, the skill, and interest of the anes-
thesiologist. Nitrous oxide still remains the most
useful gas for inhalation anesthesia. In mixtures of
3% liters to one of oxygen, its administration just
as a contraction begins and continued to the height
of the contraction is eminently successful in spon-
bb taneous delivery. A similar level of analgesia can be
reached with any inhalation agent, but the lack of
odor of nitrous oxide and its non-explosiveness are
especially attractive. This analgesic level, however,
is unsafe if forceps are to be applied. Immediate
change to first plane anesthesia is instituted. Here
again, any inhalation agent other than nitrous ox-
ide can be employed. Because of its rapid induc-
tion and potency, cyclopropane is by far our first
choice. Ethylene, ether, vinethene,@ trilene* or
&woform, if cyclopropane is not available, will
`Provide satisfactory working conditions.

J.A.M.w.A.-MARcH 1956

Under ideal circumstances, intravenous pento-
thal@ sodium is satisfactory. The conditions for its
use are a visible capur, an ample pelvis, forceps
already in the obstetrician's hands, no teaching to
be done, and a functional venipuncture. Rapid in-
jection of 7.0 to 10 cc. of 2% percent pentothal,
and application of the forceps in 15 seconds by the
clock will result in the delivery of an infant as
active as if no depressant drugs were used. Apnea
in the mother is usually prevented by the stimu-
lation of the obstetric maneuvers, Of course, equip
ment must be at hand for artificial ventilation, and
must be used promptly and properly if apnea
should occur.

A few principles for selection of method of pain
relief have become apparent during the past few
years:

1. A dyspneic patient should never be allowed
to "push" whether the dyspnea is the result of pul-
monary or cardiac disease. Continuous caudal
analgesia is our first choice in this group.

2. Patients with obstetric hemorrhage or se-
vere anemia should not be given spinal or epidural
block. Hypotension is much more frequent in this
group because of hypovolemia, low hemoglobin
content of the blood, and dilatation of the pe-
ripheral vascular bed.

3. A history of a recent meal always indicates
a regional method of anesthesia. This can always
(almost always) be arranged for vaginal delivery,
but not always if cesarean section is necessary.

4. A tight uterus can be relaxed only with third
plane anesthesia. Any drug can be used to reach
third plane, except ethylene and nitrous oxide. Cy.
clopropane is by far the most rapid one. Nerve
blocks and muscle relaxants are of no use.

5. Spinal anesthesia is not used if there is a
history of syphilis, or if a high fever is present, or
if central nervous system disease is present,

6. Patients with centra1 nervous system disease
(and there is a surprising number of them) should
have a tracheotomy set at the bedside and it should
be used electively if there is any doubt that the pa-
tient is unable to clear her own airway by coughing.
We have recently encountered, in the labor room,
cases of multiple sclerosis, myasthenia gravis, sub-
arachnoid hemorrhage, unexplained convulsions,
and brain tumor.

7. Patients with borderline disproportion, uter-
ine inertia, and cervical dystocia should not have
continuous caudal or epidural anesthesia.

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JOURNAL OF THE AMERICAN MEDKAL WOMEN'S ASSOCXATION

8. No anesthetic method, even third plane
anesthesia, will help relieve cervical dystodt
9. No method of pain relief wilI improm the
strength and length of contractions.
IO. No drug includmg morphiine will stop labor,
if it really has begun.

Aside from these medical and obstetric msid-
erations, there are no good arguments for or
against any anesthetic agent or technique if the
right drug is used, and if it is used correctly.
Complications relating to anesthesia shod be
few, and fatal complications should be zero. Aspi-
ration of vomitus should be prevented by use of
regional anesthesia wherever possible. Intentional
emptying of the stomach is not practiced as much
in these cases as on a general surgical service, be-
cause of danger of precipitate delivery, and of in-
creasing hemorrhage. When vomiting has occurred,
even in the head down position, the jaws are sep
arated and the contents scooped out. Suction is of
no assistance and a waste of time when solid vom-
itus is present. The pulse must be followed and its
state reported at frequent intervals. A sudden
weakening or disappearance calls for immediate
tracheotomy. The use of a laryngoscope in a mouth
clamped tight shut and full of solid food is im-
possible. Introduction of a blind nasal endotracheal
tube only causes tremendous epistaxis and a tube
occluded with food. Horizontal incision through
the cricothyroid membrane is the quickest, least
bloody approach. With moderate extension of the
head, the cricoid cartilage holds the lumen of the
trachea open, allowing suctioning immediately. We
believe tracheotomy preferable to a paralyzing dose
of a relaxant in the face of acute anoxia. Although
we have not needed to do a tracheotomy on the
obstretic service for 17 years, equipment for it is
always available.

Hypotension as an anesthetic cause of death
ranks as high as aspiration of vomitus. ProphyIac-
tic measures consist of bringing blood volume up
to normal with blood, or second best, a plasma
expander; oxygen therapy for cardiac and pulmo-
nary disease in the antepartum period; frequent
blood pressure observations before and immediately
after spinal and caudal anesthesia; and putting the
legs in stirrups as soon as a patient resumes the
supine position after a saddle spinal anesthesia.
Therapeutic measures consist of intravenous vaso-
pressor drug, elevating the legs, oxygen therapy,
and replacing blood volume. The anesthesiologist
should always know what vein he will choose to
use next, if an intravenous needfe becomes dis-
lodged. The externaf jugular veins are most useful,
while iliac crest or sternal puncture should be kept
in mind if venipuncture fails. Headache following
spinal anesthesia is an uncomfortable and usually
unnecessary complication. Prophylactically, it is
unwise to choose that route for anesthesia if hi?
tory of previous spinal or other severe headache
exists. If dehydration is not allowed to occur and
if only one small hole is made in the dura, head-
aches should not occur. Once present, it is success-
fully treated by introducing generous amounts of
saline epidurally. Practically, a catheter is intro-
duced caudally for about 12 inches, and an initial
dose of 40 cc. of isotonic saline pushed through
the catheter. Usually, ambulation can be under-
taken within a few minutes, with marked relief of
the headache. To date, 80 cc. has been our maxi-
mum initial dose. The catheter is left in place
overnight, and a second dose of saline introduced
before removing the catheter. Coccygodynia occurs
quite frequently after conrinuods caudal anesthesia
even with an easy placement of the needle. "his
symptom is temporary, and needs no treatment.

J.A.M.\Y`.A.-VVor., 11. Pk'. 3