UTERINE INERTIABY UMOH EMMANUEL

DEFINITION

abnormal relaxation of the uterus during labor, causing a lack of obstetric progress, or after childbirth, causing uterine hemorrhage.

Can be associated with dystocia

CLASSIFICATION

HYPOTONIC INERTIA : a. Primary Uterine inertia b. Secondary inertia HYPERTONIC INERTIA: a. Colicky Uterus b. Hyperactive lower uterine segment

PRIMARY UTERINE INERTIA

Is characterized by inefficient contractions from the very beginning of labor, the contractions are usually weak and short, while the pauses between them are long. Frequent, but ineffective contractions may also occur.

Usually occurs in general asthenia conditions, endocrine disorders, infantilism, malformation of the genitalia( uterus bicornuate and unicornus), myoma of the uterus and obesity.

AETIOLOGY

Unknown but the following factors may be incriminated:

GENERAL FACTORS:Primigravida particularly elderly.

Anaemia and asthenia. Nervous and emotional as anxiety and fear. Hormonal due to deficient prostaglandins or

oxytocin as in induced labour. Improper use of analgesics.

CONTD.

LOCAL FACTORS:Overdistension of the uterus in multiple pregnancy and polyhydroamnions

Developmental anomalies of the uterus e.g. hypoplasia.

Myomas of the uterus interfering mechanically with contractions.

Malpresentations, malpositions and cephalopelvic disproportion. The presenting part is not fitting in the lower uterine segment leading to absence of reflex uterine contractions.

Full bladder and rectum.

Uterine inertia often results in premature discharge of the amniotic fluid in the absence amnion which stimulates the nerve elements of the uterine cervix and intensifies the uterine contraction.

Primary inertia may last to the second stage of labor to become responsible for ineffective abdominal contractions, labor thus becomes markedly prolonged.

This can lead to complications such as: fetal asphyxia, considerable bleeding in the placental and early puerperal period.

CLINICAL PICTURE OF HYPOTNIC INERTIA

Labour is prolonged. Uterine contractions are infrequent, weak and of

short duration. Slow cervical dilatation. Membranes are usually intact. The foetus and mother are usually not affected apart

from maternal anxiety due to prolonged labour. More susceptibility for retained placenta and

postpartum haemorrhage due to persistent inertia.

TOCOGRAPHY: shows infrequent waves of contractions with low amplitude.

MANAGEMENT Usually difficult to manage, but one principle is to find the

cause and treat the cause if possible.Schemes used:SCHEME 1 (KURDINOVSKIY AND SHTEIN)Castor oil, 50-60g per os; a cleansing enema in 2hrs, Quinine

0.2g six times at 30min interval after enema. 15 mins later, the 3rd,4th, 5th and 6th dose of quinine follows pituitrin injections( subcutaneously 0.25ml 4 times).

If the membranes are intact, 40,000-50,000units of folliculin or sinestrol intramuscularly may be given at the beginning of labor.

Folluculin and sinestrol increases sensitivity of the uterus to quinine, pituitrine and other uterine stimulants. Castor oil is given in an hour after the administration of folliculin, then given are cleansing enema, quinine and pituitrin.

SCHEME TWO( A.P NIKOLAEV)

Castor oil , 60g per os, then (in an hr), quinine, five 0.2g doses at 30minutes interval. After the 5th admission of quinine, a cleansing enema is given followed by an intravenous injection of 50ml of 40% glucose and 10ml of 10% Calcium Chloride. Solution of vitamin B (160mg) should be given simultaneously (i.m)

SCHEME 3 (V.N KHEMLEVSKY)

A mixture of 50g of glucose, 2g of Calcium Chloride, 0.5g of ascorbic acid, 0.3g of vitamin B1, 10 drops of dilute hydrochloric acid, and 150ml of water are given per os in a single dose. The mixture can be given in 3hrs again.

CONT.

Oxytocin and Prostoglandin have been recently used as uterine stimulants. Oxytocin is given as i.v with glucose solution (5-10units of Oxytocin in 5% of 500ml glucose by infusion)…speed of drops : 10drops per minute, increase drops after some hours depending on the condition of the patient.

Proserine plus Atropine hydrochloride can be given as 0.003g and 0.002g respectively in powder from an hour interval( 4-5times a day)

Prostaglandin is contraindicated in traumas and hypertensive patients.

SECONDARY UTERINE INERTIA

A condition that develops during the second (expulsive) stage of labor or at the end of dilation stage following normal or satisfactory uterine contractions.

ETIOLOGY

Often develops in prolonged labor due to general fatigue of the Parturient and extraction of the contractile power of the uterus.

Occurs in: Contracted pelvis large sized fetus Malpresentation, rigid Os, Cicatrical narrowing of the vagina delayed rupture of membranes

PATHPHYSIOLOGY

It often occurs after discharge of the amniotic fluid and its therefore often attended with intrauterine infection and fetal asphyxia.

MANAGEMENT

Depends on the cause , if its due to delayed rupture of the membranes, AMNIOTOMY is indicated .

When the cervix is fully dilated and the fetal head is engaged, 1ml of pitutrin or 0.25ml of Oxytocin may be given simultaneously which will rapidly stimulate uterine contractions.

GENERAL MANAGEMNET OF HYPOTONIC INERTIA

General measures:Examination to detect disproportion, malpresentation or malposition and manage according to the case.

Proper management of the first stage (see normal labour).

Prophylactic antibiotics in prolonged labour particularly if the membranes are ruptured.

CONTD.

Amniotomy:Providing that; vaginal delivery is amenable, the cervix is more than 3 cm dilatation and the presenting part occupying well the lower uterine

segment. Artificial rupture of membranes augments the

uterine contractions by: release of prostaglandins. reflex stimulation of uterine contractions when the

presenting part is brought closer to the lower uterine segment.

CONTD. Oxytocin:

Providing that there is no contraindication for it, 5 units of oxytocin (syntocinon) in 500 c.c glucose 5% is given by IV infusion starting with 10 drops per minute and increasing gradually to get a uterine contraction rate of 3 per 10 minutes.

Operative delivery: Vaginal delivery: by forceps, vacuum or breech extraction

according to the presenting part and its level providing that, cervix is fully dilated. vaginal delivery is amenable.

Caesarean section is indicated in: failure of the previous methods. contraindications to oxytocin infusion including disproportion. foetal distress before full cervical dilatation.

HYPERTONIC UTERINE INERTIA (UNCOORDINATED UTERINE ACTION)

Types Colicky uterus: incoordination of the different

parts of the uterus in contractions. Hyperactive lower uterine segment: so the

dominance of the upper segment is lost.

CLINICAL PICTURE The condition is more common in

primigravidae and characterised by: Labour is prolonged. Uterine contractions are irregular and more painful.

The pain is felt before and throughout the contractions with marked low backache often in occipito-posterior position.

High resting intrauterine pressure in between uterine contractions detected by tocography (normal value is 5-10 mmHg).

Slow cervical dilatation . Premature rupture of membranes. Foetal and maternal distress.

MANAGEMENT

General measures: as hypotonic inertia. Medical measures:

Analgesic and antispasmodic as pethidine. Epidural analgesia may be of good benefit.

Caesarean section is indicated in: Failure of the previous methods. Disproportion. Foetal distress before full cervical dilatation.

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