|
Obstetric Emergencies - Advanced |
||||||||||||||||||||||||
|
Introduction What does pregnancy mean? Other than the obvious that is! It begins with fertilization and ends approximately 40 weeks later with the birth of the baby. Many changes occur within that time period, usually without any complications. But when there are complications, the EMS provider must be prepared to recognize them and treat them appropriately and professionally. Remember, pregnancy and complications associated with pregnancy should always be assumed in a woman of child-bearing age that is complaining of abdominal pain. Anatomy and Physiology The onset of menses, termed menarche, normally begins in the early teenage years. About once a month, the ovary releases an ovum (egg) into the fallopian tube where it is transported to the uterus. The ovaries are paired glands that are about the size and shape of almonds. In addition to egg production, the ovaries are also endocrine glands that secrete the hormones estrogen and progesterone. The fallopian tubes, or oviducts, are small cilia-lined tubes that have finger-like projections called fimbriae near the ovaries that help guide the egg into the tube. The open, funnel-shaped portion of the fallopian tube is called the infundibulum, the upper 2/3 of the tube is called the ampulla, and the lower 1/3 of the tube that attaches to the uterus is called the isthmus. Fertilization usually takes place in the fallopian tube about 12 - 24 hours after ovulation and then the fertilized egg moves down into the uterus. The uterus, or womb, is a muscular organ located between the rectum and the bladder. The upper, dome-shaped portion of the uterus superior to the fallopian tubes is called the fundus. The body is the major central section of the uterus and the cervix is the inferior narrow portion that opens into the vagina. The uterus has three layers: the perimetrium is the outer layer, the myometrium is the muscular middle layer, and the inner layer where the fertilized egg implants itself is the endometrium. If the ovum is not fertilized by the male sperm, it is passed out of the body with blood, mucus, and other wastes during the menstrual period. During fertilization, the genetic material from the sperm cell (spermatozoon) and the ovum merges together into a single cell. When the ovum is fertilized (now called a zygote), then it begins dividing immediately and eventually implants itself in the uterine wall. These early stages of cell division are called cleavage For the first eight weeks of pregnancy, the developing baby is called an embryo. After that it is known as a fetus. The placenta forms with the embryo and is the exchange organ between the mother and developing embryo. The placenta is responsible for the transfer of gases, nutrients and wastes, hormone production, and the formation of a protective barrier. The amniotic sac, which is filled with amniotic fluid, forms around the embryo and provides a cushion against trauma, maintains a constant temperature, and permits fetal movement. The umbilical cord connects the fetus to the placenta. In this cord there are two arteries that carry deoxygenated blood from the fetus and one vein that carries oxygenated blood to the fetus. This vein connects to the inferior vena cava at the ductus venosus. From there the blood travels to the right atria and down into both ventricles. There is a hole between the atria called the foramen ovale which allows for this to occur. In the pulmonary artery the blood passes through the ductus arteriosus that connects to the aorta. This bypasses the lungs completely. As long as the fetus is developing in the mother's abdomen, it does not need to breathe. Deoxygenated blood passes through the liver and then into the umbilical arteries to be expelled. No blood is directly exchanged between the mother and the fetus. Gases and wastes are exhanged by diffusion across the chorionic membrane. This membrane separates the maternal and fetal blood. As soon as the baby is born, this all changes. Because of the change in ambient pressure, the ductus arteriosus closes which diverts the flow of blood to the lungs via the pulmonary arteries. The ductus venosus also closes which ends the exchange from the placenta. The foramen ovale closes and thus stops the flow of blood between the atria. Embryonic and Fetal Growth End of Month Developmental Changes 1 Formation of placenta, facial features not yet visible, limb buds form, heart forms and starts beating, the central nervous system appears at start of third week 2 Facial features visible, eyes fused, nose flat, ossification (hardening of bones) begins, limbs become distinct and digits well formed, major blood vessels form 3 Eyes almost fully developed but eyelids fused, nose develops a bridge, external ears are present, limbs fully formed and nails develop, heartbeat can be detected, fetus begins to move but cannot be felt by mother, may recognize gender 4 Face takes on human features and hair starts to grow on head, many bones ossified and joints begin to form 5 Fine hair (lanugo) covers body, fetal movements are felt by mother (quickening) 6 Eyelids separate and eyelashes form, substantial weight gain, alveolar cells begin to produce surfactant 7 Head and body more proportionate, seven-month fetus is capable of survival, fetus assumes an upside-down position 8 Subcutaneous fat deposited, chances of survival much greater at end of eighth month 9 Additional subcutaneous fat deposited, lanugo shed, bronchioles and alveoli developing at final stages, rest of body systems fully developed Maternal Changes During Pregnancy The prospective mother also undergoes physiological changes during pregnancy. The uterus increases in size, the vaginal area develops increased vascularity and a decreased pH, there is an increase in frequency of urination, and the breasts increase in size in preparation for lactation (milk production). Morning sickness (emesis gravidarum) is common in the first trimester. Morning sickness, which does not necessarily occur in the morning, is usually not a medical concern unless the mother has severe symptoms and requires hospitalization. This condition of unremitting nausea and vomiting is termed hyperemesis gravidarum. The stomach and intestines and abdominal organs are shifted upward as the uterus enlarges. Heartburn and constipation are common due to the prolonged digestive process. Hair loss increases. Increased pigmentation of the skin may occur, especially around the eyes and on the cheekbones, in the areolae of the breasts, and the lower abdomen. Stretch marks (striae) appear on the skin of the abdomen due to enlargement of the uterus during pregnancy. The pregnant woman will commonly complain of low back pain due to the swayback position (lordosis) she is in from the size and weight of her abdomen. The mother's heart position is shifted slightly. Cardiac output increases and the heart rate increases 15 - 20 beats per minute. Total blood volume increases by 30%, plasma volume increases by 50% and blood pressure decreases 10 - 15 mm Hg. If the mother lays flat on her back during the third trimester, the weight of the baby may compress the inferior vena cava and interfere with circulation causing a condition called supine hypotensive syndrome. Hemorrhoids, edema in the extremities, and varicose veins may appear. Tidal volume and minute ventilation increase by 30 - 40%. The mother has an average weight gain of 0.5 kg per week. Calcium and iron need to be supplemented because of the demands of the fetus for these nutrients. Terminology Emergency medical personnel should be familiar with obstetrical terminology. The following terms are a few that might be used during an obstetrical emergency: Gestation/Antepartum - period of time spanning conception and labor Grand Multipara - a woman who has had seven (7) deliveries or more Gravida - the number of pregnancies, whether or not they result in a live birth Multigravida - a woman who has been pregnant more than once Multipara - a woman who has delivered more than one (1) viable infant Nullipara - a woman who has not been delivered of a viable infant (para 0) Para - the number of live births Perinatal - of or pertaining to the time and process of giving birth or being born Postpartum - after childbirth Primigravida - a woman pregnant for the first time Primipara - a woman who has given birth to one viable infant (para 1) Term - a pregnancy that has reached 40 weeks gestation Assessment As with any other emergency you respond to, the very first thing you do is size-up the scene. Make sure it is safe for you to enter before doing so. Consider what body substance isolation equipment you may need (gloves, gown, and goggles should be worn because splashing of body fluids is highly likely) and have it ready, if not already on, when you enter the scene. Your initial assessment should give you a general impression of the patient and what is happening. With these types of calls, your patient usually has a patent airway, is breathing, and has a pulse. But you should always keep the ABC's in the back of your mind and assess them if they are not obvious when you arrive at the patient's side. The focused assessment should focus on the obvious - the whole reason you were called. This means you need to begin asking some questions and getting a history of what has happened thus far. For example: 1. Is the patient having contractions? 2. When did the contractions start, what is the duration of each contraction, and how far apart are they? 3. Has the bag of waters broken? 4. Does the patient feel an urge to push or go to the bathroom? 5. What is the length of gestation? 6. What is the anticipated due date (if known)? 7. Has the patient been under medical care? 8. Is this the first pregnancy? How many times has the patient been pregnant? (Gravidity) 9. How many of the past pregnancies remained viable to birth? (Parity) 10. Were there any complications, such as bleeding or premature delivery, with the previous pregnancy/birth? What type of delivery - vaginal or cesarean? 11. How long did the previous labor last? 12. Obtain a SAMPLE (Sign and symptoms, Allergies, Medications, Past medical history, Last oral intake, Events leading up to the incident) history. All of these questions will give you pertinent information and should assist you in making a decision about whether to transport the patient now or to prepare for a delivery on the scene. You or your partner should time the contractions and gauge how strong they are by palpating the patient's abdomen and watching the patient's reactions to the contractions. The uterus is above the symphysis pubis at 12 - 16 weeks gestation, at the level of the umbilicus at 24 weeks and near the xiphoid process at term. Fetal heart tones may be heard with a stethoscope after 16 weeks. The fetal heart rate should be between 120 and 160 beats per minute. Anything less than that or more than that may indicate fetal distress. You should also visualize the vaginal area for a bulging perineum (the region medial to the thighs and buttocks that contains the external genitals and anus) or crowning during the contractions. These things indicate that the birth is imminent and you should prepare for it quickly. Pre-Delivery Complications Ectopic Pregnancy If the fertilized ovum embeds anywhere other than the uterus, this is called an ectopic pregnancy. Most ectopic pregnancies occur in the fallopian tubes but they can occur in the abdomen, ovaries, or cervix. Maternal death is usually the result of hemorrhage. Signs and symptoms include abdominal pain, vaginal bleeding, shoulder pain, nausea, vomiting, and shock. This patient should get high-flow oxygen, IV therapy, constant monitoring, and rapid transport. Risk factors for ectopic pregnancy are:
Gestational Diabetes Gestational diabetes can occur during pregnancy and usually disappears following delivery. It is due to changes in glucose metabolism during pregnancy. A potential complication of gestational diabetes is development of a large fetus which can cause problems with delivery. Pre-eclampsia and Eclampsia Pre-eclampsia, the first stage of toxemia, is a condition in which the mother-to-be has a history of weight gain, swelling in the extremities, hypertension, protein in the urine, and possibly headaches and visual disturbances. When this condition progresses to the point where the patient experiences a seizure, the patient is said to be eclamptic. Monitor the airway, give high flow oxygen, use a BVM if necessary to assist respirations, place the mother on her left side, monitor vital signs, initiate IV therapy, and transport. If seizures occur, be prepared to administer medications per protocol. Magnesium Sulfate 1-4 gm IV over 3 minutes, Diazepam 5-10 mg IV slowly and/or Hydralazine (antihypertensive) may be necessary. Risk factors for toxemia include:
Abortion An abortion is a fetus that is delivered before the 20th week. There are different classifications of abortion:
Watch for hemorrhaging and for any fetal tissue that may be expelled. If any tissue is expelled, take it to the hospital for analysis. This patient should receive high-flow oxygen. Monitor the patient for shock during transport. If necessary, initiate IV therapy. Provide emotional support. Preterm Labor Preterm birth is defined as birth between 20 and 37 weeks of gestation. This carries a high risk of infant mortality or long-term medical problems. Early signs and symptoms of preterm labor are usually not described as "contractions". They include a new onset of pain in the back, thighs, pelvis, or abdomen; change in vaginal discharge; pressure in the pelvis, bladder, or rectum; menstrual-like cramps; vaginal pain; or abdominal tightenings. These patients should be transported for evaluation. Be prepared for delivery and resuscitation of the neonate. Abruptio Placenta Abruptio placenta occurs when the placenta separates from the uterus. The patient will complain of sudden, severe abdominal pain. The bleeding that occurs with this condition is usually always internal and can be life threatening. Monitor the airway, give high flow oxygen, watch for shock, establish an IV, monitor vital signs, and transport. Risk factors for abruptio placenta include:
Placenta Previa Placenta previa is a condition in which the placenta embeds itself low in the uterus and is close to or over the cervix. When the patient's cervix begins to dilate during labor, the placenta tears and bleeding can be profuse. This is usually painless. Placenta previa can be total, when the placenta completely covers the cervical os, partial, when the part of the cervical os is covered by the placenta, or a low placenta, when the placenta is close to the cervical os. Monitor the airway, give high flow oxygen, watch for shock, establish an IV, monitor vital signs and transport. Risk factors for placenta previa are:
Trauma in Pregnancy Trauma during pregnancy is the most frequent cause of nonobstetrical maternal death. Three major causes of injury are motor vehicle accidents, falls, and penetrating objects. Care for the pregnant trauma patient is essentially the same as with other trauma victims, but there are some differences. Blunt trauma to the abdomen may cause abruptio placenta, premature rupture of the membranes, uterine rupture, amniotic fluid embolism, or preterm labor. Broken ribs or pelvic fractures may cause uterine lacerations and significant blood loss. Because survival of the fetus depends wholly upon survival of the mother, safe and rapid transport to the closest appropriate facility should be performed. Remember to elevate the right side of the backboard with pillows or wedges to avoid supine hypotensive syndrome. Administer high-flow oxygen, establish 2 large-bore IV's, treat for shock, and be prepared for delivery. If traumatic arrest occurs, you should perform CPR and transport immediately. Perform resuscitative measures as you would on the nonpregnant patient. Post-mortem cesarian section is an extremely controversial issue and generally not allowed in the prehospital environment. Labor and Delivery The birth process, also known as parturition or labor, is divided into three phases. The first phase begins with the uterine contractions and ends when the cervix is fully dilated. The cervix dilates to 10 cm in diameter. Sometimes during this phase, the bag of waters usually ruptures. The second phase begins when the cervix is fully dilated and the baby begins to pass through the birth canal. The contractions are closer together and stronger. Crowning, when the top of the baby's head is visible between contractions, occurs and the baby is born. The third phase begins after the baby is born and ends with the delivery of the placenta. When a patient tells you she is having contractions 1 - 2 minutes apart, she feels the urge to bear down or have a bowel movement (this means the baby is in the birth canal), or you see crowning, then rest assured the birth is imminent and preparations better be underway because that baby is coming whether you are ready or not! Body substance isolation precautions should be taken: gloves, gown, and eye protection should be worn. If at all possible, try to have some privacy for the patient. Place sheets, towels, or the sterile sheets from the obstetrics kit over the patient's legs and abdomen and under the buttocks. If time permits, give the mother some oxygen and start an IV per protocol. If crowning is visible, place a gloved hand on the presenting part with a little bit of pressure in order to prevent an explosive delivery. Remember to reassure the mother and help her to breathe if she gets anxious. Panting or breathing deeply may help her during the contractions. If the amniotic sac has not ruptured yet, you need to puncture it. As the baby's head is born make sure to wipe the amniotic fluid from the nose and mouth and suction with a bulb syringe. Suction the mouth first, then the nose. Most babies come out face down and then will rotate so that the shoulders can come out. Make sure that the umbilical cord is not wrapped around the baby's neck. If it is, slip it off. If you cannot slip it off, you will need to clamp it in two places and cut it. The baby's body is usually delivered very quickly after that. Note the time! Keep the baby's head lower than the body in order to let gravity help keep secretions flowing out. Suction vigorously especially if there was meconium staining in the amniotic fluid. Meconium is the greenish or brownish coloring sometimes seen when the baby has its first bowel movement prior to birth. It is a thick, sticky substance that can cause serious lung complications for the baby if inhaled. As soon as the baby's head is born, suction the baby's airway thoroughly. Immediately after the baby is fully delivered, intubate and suction again. Remove the tube and suction again until little or no meconium is present in the airway. Dry the baby and wrap it in a warm, clean blanket. If the umbilical cord has not already been cut, make sure it is no longer pulsating and clamp it approximately 4 - 5 inches from the baby and a second one 2 - 3 inches from the first. Cut between the clamps and make sure that there is no leakage of blood on the baby's side. If there is, use a second clamp to prevent further bleeding. Check the APGAR score at one and five minutes after birth. Most babies score 8 - 10 at one minute. An APGAR of less than 6 requires resuscitation.
A baby should begin breathing within 30 seconds. If it does not, stimulate it by rubbing its back or flicking the bottom of the soles of the feet. Provide artificial respirations at a rate of 40 - 60 per minute if it still does not breathe adequately. If the heart rate is less than 100 beats per minute, assist respirations at a rate of 40 - 60 per minute and reassess. Chest compressions at a rate of 120 per minute should be started if the pulse does not increase or if it is less than 80. Medications and fluids may be given intravenously, intraosseous, or endotracheally if necessary. The priority of resuscitative measures are:
Remember to continue caring for the mother during this time also. The placenta (now termed the afterbirth) should be delivered within 20 - 30 minutes after the birth of the baby. Be sure to save it and transport it to the hospital also. Clean the mother up, place a sanitary napkin over the perineum. Prepare her for transport to the hospital. As with all patients, an ongoing assessment is necessary. Monitor vital signs, watch for hemorrhaging, and monitor any interventions you may have performed en route. Postpartum Hemorrhage If postpartum hemorrhaging (more than 500 ml) is present, massaging the uterus in a circular motion will help the uterus contract and slow down bleeding. If she is able to and there are no complications with the baby, she may choose to nurse her baby. Oxytocin (10 units oxytocin added to 1 L Lactated Ringer's or normal saline) may be administered per protocol. Transport both patients to the hospital for evaluation. The mother is at risk for postpartum hemorrhaging if:
Complications During Delivery There are some complications with the delivery process that all EMS personnel should be aware of. Cephalopelvic Disproportion Cephalopelvic disproportion occurs when the baby's head is too big to pass through the pelvis. If this condition is suspected, transport immediately. Definitive treatment is a cesarean section. Administer oxygen, begin IV therapy and monitor vital signs during transport. Cephalopelvic disproportion or difficult delivery is more likely if:
Abnormal Presentation The majority of babies are born in a head first, or cephalic presentation. However, sometimes other parts of the body present first. If the buttocks present first, this is known as a frank breech. Breech presentation is more common in premature infants and multiple births. Support the baby's body, making sure not to compress the umbilical cord, as it is born. If the head does not deliver quickly, place two fingers inside the vagina and push the vaginal wall away from the baby's nose and mouth in order to prevent suffocation. You will have to transport the mother and baby in this position to the hospital. Another abnormal presentation is limb presentation. If one or both feet enter the pelvis, this is termed footling breech. If the baby is lying transverse in the uterus, you may observe a shoulder presentation. If you observe a chin presentation, the baby cannot be delivered vaginally because the neck is hyperextended and will break if extended more. All of these conditions are extreme emergencies and rapid transport is indicated. Never attempt to replace a protruding limb. Elevate the hips to reduce gravity on the cervix, provide oxygen, establish IV access, and transport. Shoulder Dystocia Shoulder dystocia occurs when the baby's shoulders get stuck against the mother's symphysis pubis, the baby cannot come through and the baby's head and neck retracts back toward the perineum. Position the mother with her knees flexed back toward her chest or on her left side in a knee chest position and attempt to guide the infant's shoulders out. If this is not possible, transport immediately. Prolapsed Umbilical Cord A prolapsed umbilical cord occurs when the umbilical cord is delivered first. The problem with this situation is that as the baby's head is coming down the birth canal it will compress the umbilical cord. You must place a gloved hand inside the vaginal canal and apply gentle pressure on the head or presenting part in order to keep the baby from being born. Apply a moist towel over the umbilical cord to prevent it from drying out. High flow oxygen should be placed on the mother. She should be told not to bear down and "blow" during contractions. Mother and EMT should be transported in this position to the hospital quickly where a cesarean section will be performed. Precipitous Delivery A precipitous delivery is a rapid spontaneous delivery less than three hours from the onset of labor to birth. If the mother is multiparous, you should be prepared for a precipitous delivery. Dangers are tearing of the umbilical cord, lacerations of the perineum, and possibly cerebral trauma to the infant. Be alert for an explosive delivery. Monitor the mother and baby closely. Multiple Births Occasionally you may have a patient who is expecting more than one baby. The delivery process is the same although you will probably need more assistance. Keep in mind that these babies may be smaller and premature. Remember to note the times of ALL the births. Premature babies are more at risk for developing infections and hypothermia. They are typically smaller than a full term baby and sometimes they will not be fully developed and will require respiratory assistance. After the first baby is born, go ahead and clamp and cut the umbilical cord. Another problem with multiple births is that complications can occur if the second baby takes too long to deliver. Uterine Inversion Uterine inversion is a rare occurrence. It is when the uterus turns inside out and protrudes from the cervix. Uterine inversion can be caused by pulling on the umbilical cord to hasten delivery of the placenta. The patient may experience hemorrhaging, lower abdominal pain and shock. Give high flow oxygen, begin IV therapy, and make one attempt (per medical control) at replacing the uterus. To do this, use the palm of your hand and push toward the vagina. If this is unsuccessful, cover with moist sterile dressings and transport rapidly. Uterine Rupture Uterine rupture is the actual tearing of the uterus. This patient will probably be in shock. The abdomen will be tender and rigid. Give high flow oxygen, begin IV therapy, monitor vital signs, consider MAST, and transport rapidly. Risk factors for uterine rupture are:
Pulmonary Embolism Pulmonary embolism is the most common cause of maternal death and can occur at any time before, during, or after labor. The patient may experience sudden dyspnea, chest pain, tachycardia, tachypnea, and possibly hypotension. Support ventilations if necessary, give high flow oxygen, monitor EKG, initiate IV therapy, start CPR if needed, and transport quickly. Stillbirth Occasionally, childbirth may result in a stillbirth. A stillborn baby is lifeless, without a spontaneous pulse or respirations, it may have a soft head, a foul odor, pooling of blood, and possibly blisters on the skin. In general, you should not attempt resuscitation. Do wrap the baby in a blanket or a towel and offer it to the parents to see it or hold it if they wish. This may help the parents work through the grief process. The parents will feel guilt and sadness. Reassure the parents that they should not blame themselves. Remember that most of the time the role of the EMS provider during a birth is mainly supportive in nature. Occasionally there are complications and you must know how to handle them.
|