HYPOTONIC AND HYPERTONIC CONTRACTIONS

POWER OF LABOR

What is another important requirement for a successful labor?

PRIMARY FORCES

this consists of the involuntary contraction of the uterine muscles fibers, which are stimulated by a pacemaker located in the upper uterine segment 

SECONDARY POWERS

This consist of the voluntary use of abdominal muscles during the second stage of labor to facilitate descent and delivery of fetus

see a care provider for evaluation of contractions

As a rule, what should a woman do even if she thinks what she is feeling cannot be true labor?

UTEROTUBAL PACEMAKER

This may not operate in a synchronous manner. Sometimes contractions are weak, strong, and irregular. This mild incoordination of early labor improves after a few hours as the pacemaker becomes more attuned to calcium.

CALCIUM

is an important messenger required within the uterine muscle cell to result in muscle contraction and affects concentrations in the myometrium.

reversed and ineffective contractions causing tightening rather than dilatation of the cervix

What happens when contractions originate in the lower uterine segment rather than in the fundus?

pain in the lower abdomen

What may a woman feel when strong uterine contractions do not cause cervical dilatation?

UNCOORDINATED CONTRACTIONS

What can additional pacemaker sites in the uterus cause during labor?

INCREMENT

 intensity of contraction increases

ACME

contraction is at its strongest

DECREMENT

intensity decreases

Increment, Acme, Decrement

What are the Phases of Contractions

Duration, Intensity, and Frequency

Contraction are assessed according to?

DURATION

length of contraction from increment to decrement

INTENSITY

strength of contraction at the acme. Mild–Moderate–Strong

FREQUENCY

onset of one contraction to the onset of the next contraction. Increment to Increment

DECREASE FROM 10 MNS TO 2-3 MINS

What happens to relaxation intervals as labor progresses?

20-30s to 60-70s

How does the duration of contractions change during the first stage of labor?

10-15 mmHg and increased to 25 mmHg to 50 mmHg.

What is the normal uterine resting tone?

HYPOTONIC CONTRACTIONS

What type of contractions may occur during the active phase of labor?

Cervical dilatation occurs more rapidly and contractions grow stronger, lasting 40–60 seconds every 3–5 minutes

What happens to cervical dilatation and contractions during the active phase of labor?

grow much stronger and last longer

How do contractions change compared to the latent phase?

INFREQUENT CONTRACTIONS

What characterizes contractions that occur with decreased intensity and not more than 2–3 in 10 minutes?

< 10 mmHg, ≤ 25 mmHg

What are the resting tone and strength values in hypotonic contractions?

contractions reduced in intensity, labor progresses slowly

How does polyhydramnios affect labor?

BLADDER DISTENTION

What condition can interfere with normal uterine contractions due to the structural closeness of the uterus and bladder?

BOWEL DISTENTION

This can affect the muscles, tissues, and nerves in the pelvis. In extreme cases, this can cause the uterus to slip out of place.

OVERSTRETCH UTERUS

What condition occurs when the uterus becomes deficient in firmness and supporting muscles and ligaments become lax (e.g., multiple gestation, macrosomia)?

ANALGESIA ADMINISTRATION

What can slow labor if given before the cervix is dilated to 3–4 cm?

SYMPATHETIC BLOCK

What can lead to maternal vasodilation, active hypotension, reduced cardiac preload, and decreased cardiac volume during labor?

REDUCED UTEROPLACENTAL PERFUSION

What effect does a drop in blood pressure have on the uterus?

HYPOCONTRACTILITY

What is characterized by infrequent and weak contractions, less than 3–4 per 10 minutes, lasting less than 45 seconds?

PROTRACTION OR FAILURE IN THE ACTIVE PHASE

What is indicated by cervical dilation slower than 1–2 cm/hour or no cervical change for >6 hours with inadequate contractions?

palpate uterine fundus, obtain blood pressure, assess lochia every 15 minutes

What should be done in the first hour after birth to ensure postpartal contractions are adequate?

AMNIOTOMY

What stimulates contractions when membranes are ruptured and the presenting part is closely applied to the lower uterine segment?

cervical dilatation > 4 cm, adequate fetal descent (station -2 or lower), presenting part well-applied to lower uterine segment

When should amniotomy be attempted?

DORSAL RECUMBENT

What position is the woman asked to assume during an amniotomy?

AMNIOHOOK OR HEMOSTAT

What instruments are passed vaginally during an amniotomy?

HYPERTONIC CONTRACTIONS

What type of contractions are frequent, with increased intensity and increased uterine tone?

HYPERTONIC CONTRACTIONS

What causes contractions when more than one uterine pacemaker is active or myometrial fibers do not relax after a contraction?

resting phase between contractions and absence of late decelerations in FHR

What should be monitored to ensure contractions and fetal heart rate are safe?

LYING ON THE LEFT SIDE

What position is recommended during pregnancy to improve circulation and blood flow to the fetus, uterus, and kidneys?

I.V. FLUID LOADING

What intervention helps the uterus function properly and keeps the umbilical cord from being compressed?

INTRAUTERINE PRESSURE CATHETER

is a device that measures the pressure generated by each contraction, recorded quantitatively in Montevideo units (MVU) 

LESS THAN 200–250 MVU

What level of uterine activity is considered inadequate for effective labor?