(left picture courtesy of Michael Lovelace, right upper picture courtesy of Leslie Lewis, right lower picture courtesy of Elisabeth Abel) 1 2 •Consider the possibility of pregnancy in women aged 10 to 50. •Injury may be intentional or non-intentional. MVCs and falls most common; homicides and suicides account for 1/3 to ½ of all fatalities. •Fetal mortality is 80 % with maternal shock, so early, aggressive treatment of mom is the key to survival. •The 1st indication of maternal hypovolemia will be seen in an abnormal fetal heart rate. Remember that the uterus is not considered and vital organ and in an hemorrhagic state the blood will be diverted away from the placenta to support the mother hemodynamically. 3 •Subsequent slides review each system—don’t talk in detail about each one as they will be discussed on following slides. •Assessment, diagnostics, and management all are impacted by the anatomic and physiologic changes that occur during pregnancy. It is important to know what is normal that will assist in correctly assessing and treating the pregnant trauma patient. • Due to these normal anatomic and physiologic changes identification of injuries can be missed. Do not assume all is well as long as the maternal vital signs are stable. •(picture courtesy of Leslie Lewis) 4 •The capillaries of the upper respiratory passages become engorged during pregnancy, increasing susceptibility to nasal bleeding. If a nasal approach is required, transport personnel should use an endotracheal tube 1 to 1.5 cm smaller than would normally be selected •Because the diaphragm is pushed upwards by the growing uterus, lung volume decreases. During the second half of pregnancy, the diaphragm rises about 4 cm, severely limiting respiratory reserve and making the pregnant mother especially vulnerable to the effects of acute lung injury and less tolerant of hypoxia. •Minute ventilation increases primarily because of an increase in tidal volume caused by increased progesterone levels during pregnancy. Hypocapnea (PaCO2 under 30mmHg) and a respiratory alkalosis are therefore common in late pregnancy. Accordingly, a PaCO2 of 35 to 40 mmHg may indicate impending respiratory failure in these patients. The forced vital capacity fluctuates slightly during pregnancy due to equal and opposite changes in inspiratory capacity (which increases) and residual volume (which decreases). •Total body oxygen consumption is increased by 15 percent in pregnancy, primarily due to the increased needs of the uterus, fetus, and placenta. Coupled with an up to 20% decrease in functional residual capacity, apneic pregnant patients desaturate about 2.5 times more rapidly than non-pregnant patients. •(picture courtesy of Tracy Meyer) 5 •Blood volume increases steadily throughout pregnancy and plateaus at 34 weeks gestation with a total increase of up to 50%. This is a result of increases in plasma volume as well as in the cellular components. •After the 10th week of pregnancy, cardiac output can be increased by 1.0 to 1.5 L/minute due to an increase in plasma volume and a decrease in vascular resistance of the uterus and placenta. •Heart rate increases gradually by 10 to 15 beats/minute throughout pregnancy, reaching a maximum rate by the third semester. •Blood pressure declines by five to 15 mm Hg during the second trimester, before returning to near-normal levels at term. •Because of the increased intravascular volume, the pregnant patient can lose a significant amount of blood, 1200 to 1500 ml, before tachycardia, hypotension, and other signs of hypovolemia occur. This amount of blood loss will cause a 10 to 20 percent decrease in uterine blood flow, as uterine artery vasoconstriction is one of the first responses to maternal blood loss. Thus, the fetus may be in distress and the placenta underperfused while the mother’s condition and vital signs appear stable. •With maternal blood loss fetal fetal distress precedes change in maternal vital signs. •(unknown source, looking for new picture) 6 •When a woman in her second half of pregnancy lies supine, the uterus compresses her inferior vena cava and impairs blood return to the heart. This situation can lead to a 20% decrease in cardiac output and is responsible for the supine hypotensive syndrome seen in 20% of women after 20 weeks gestation. •Although very basic, a commonly forgotten remedy for hypotension in the pregnant patient is displacement of the uterus to the left, most easily accomplished by having the patient lie in the left lateral recumbent position. •In the case of the trauma patient who requires spinal immobilization, tilting the backboard with towels or a blanket under the hip or manually pulling the uterus to the left will adequately displace the uterus off the inferior vena cava. •Manual displacement will hurt! •(picture courtesy of Karen Snider/Elisabeth Ables) 7 •The gravid uterus increases to 1200 g from its normal size of 60-80 g. • The uterus remains an intrapelvic organ until approximately the 12th week of gestation. It is thick walled and well- protected. The primary risk of trauma is abortion and isoimmunization. • By 20 weeks, the uterus is at the umbilicus and now an extrapelvic organ. Additional risk from trauma include amniotic fluid embolism and abruptio placenta. • At 34 to 36 weeks, it reaches the costal margin. Amniotic fluid volume decreases with fetal growth thus providing less protection. The uterus is now thin-walled providing less protection making the fetus more susceptible to trauma. In late pregnancy, injuries that would normally involve the abdominal organs may now affect the bladder, uterus, fetus, and placenta. • Uterine blood flow increases from 60 ml/min to 600ml/min. The circulating blood volume of a pregnant patient circulates through the uterus in less than 10 minutes increasing the risk of exsanguination and hemorrhage. • Anatomic alterations in the maternal thoracic cavity include elevation of the diaphragm by as much as 4 cm. Tension pneumothorax may develop more quickly due to the elevated diaphragm and pulmonary hyperventilation. The maternal heart is also elevated and rotated forward to the left. This is reflected in the 12 lead ECG tracing as a left axis deviation, flattened or inverted T waves, and prominent Q waves in lead III. •These changes alter the usual landmarks for some common trauma procedures. If a chest tube is to be placed in a pregnant patient, enter the 8 •In preparation for birth, increased progesterone levels cause relaxation of the ligaments supporting the pelvic joints. •The symphysis pubis widens and the sacroiliac joint spaces increase causing changes in the pregnant women’s center of gravity. •These changes not only cause instability of the pelvis but also make interpretation of pelvic radiographs more difficult. (Symphysis pubis widens from 4mm to 8mm). •(picture from previous version) 9 •Increased levels of progesterone and estrogen inhibit gastrointestinal motility during pregnancy, as does physical pressure from the enlarging uterus. •This physiological ileus, coupled with decreased competency of the gastroesophageal sphincter, increases the potential for aspiration. •Pregnant trauma patients, should be assumed to have a full stomach. Early insertion of a gastric tube may protect the patient from aspiration. •The glomerular filtration rate is increased. In addition to an increased urine volume, certain renal function test results may be altered. Serum creatinine and serum urea nitrogen will decrease to one half of normal pre-pregnancy levels. Normal changes that occur during pregnancy must be recognized in order to prevent misinterpretation of test results. 10 •Red and white blood cell production, as well as that of some clotting factors, increases in pregnancy It is not unusual to see white blood cell counts of 15,000/mm3 during pregnancy and up to 25,000/mm3 during labor. •This physiologic anemia is due to a delusional effect of plasma volume increasing by 50% but red blood cell volume increasing by only 18-30%. Thus, the average hematocrit in a pregnant patient is 32-34%. •Because of the decreased erythrocyte to plasma ratio, a decreased oxygen carrying capacity of the blood also exists and must be taken into account when resuscitating the pregnant trauma patient. Supplemental high flow oxygen and early blood administration should be considered early in the resuscitation process. •(picture from previous version) 11 •In both blunt and penetrating trauma, fetal mortality generally exceeds maternal death. •The uterus and amniotic fluid act as an anatomic shield to protect the fetus from injury. In advanced stages of pregnancy, fetal injury and death can occur with direct injury to the abdomen from maternal contact with the steering wheel or dashboard, improper placement of the lap portion of the seat belt, or a direct abdominal blow from a blunt object. Indirect fetal injury can occur from rapid deceleration or compression, contracoup forces, or shearing effects. •Abruptio placenta is common following blunt abdominal trauma. Pelvic fractures late in pregnancy are associated with fetal skull fractures due to the position of the fetal head within the pelvic ring. Bladder rupture is also an associated occurrence with pelvic fractures. •Maternal morbidity and mortality from penetrating injuries to the gravid abdomen is generally low. The fetus, however, is more susceptible and generally does not fare as well. •Domestic violence occurs in up to 17% of women during pregnancy (see Appendix H). •(picture courtesy of Karen Snider/Elisabeth Able) 12 •Initial management of the pregnant trauma patient should not differ from that of the non-gravid patient with the exception of patient positioning. Although this simple intervention is basic to obstetrical practitioners, it is sometimes overlooked by transport team members. Prehospital providers should transport women pregnant greater than 20 weeks estimated gestational age (EGA) in a lateral decubitus position to displace the gravid uterus off the inferior vena cava and prevent supine hypotension. •As with any trauma resuscitation, the goals of initial management are securing and maintaining an airway, ensuring breathing, and maintaining circulation. For optimal outcome of mother and fetus, assess and resuscitate the mother first, then assess the fetus before conducting a secondary survey of the mother. The fetus should be assessed by performing an abdominal exam to include auscultation of fetal heart tones, fetal activity, and for the presence of maternal vaginal bleeding. •(picture courtesy of Tracy Meyer) 13 •Waiting until respiratory failure is evident by ABG unnecessarily places the fetus at risk for hypoxia. All pregnant women need to be preoxygenated prior to intubation due to a decreased functional residual capacity that predisposes them to much more rapid desaturation during the procedure. •Oxygen consumption increases by 15% by the third trimester. Sixty seconds of apnea results in a decreased PaO2 of 29% in pregnant patients, compared with 11% in non-pregnant patients. A longer period of preoxygenation is required (as long as three minutes or more if clinically appropriate) to equilibrate oxygen levels across the placenta to the fetus. •Rapid sequence intubation can be safely performed in pregnant patients, but medication dosages may need to be adjusted. Etomidate and ketamine are safe to use in pregnancy, but the ketamine dose is reduced. Succinylcholine and rocuronium, both of which are safe for use in pregnant patients, have relatively longer durations of action when given to pregnant patients in doses appropriate for RSI, and the onset of action is quicker when compared with non-pregnant patients. •Pregnant women are at an increased risk for gastric reflux. Ensure cricoid pressure during the endotracheal intubation. Prompt insertion of a gastric tube should also be completed after intubation. •In late pregnancy, chest tube insertion should be performed at the 3rd to 4th intercostal space. •(picture from previous version) 14 •It is important to remember: apparently normal vital signs in a pregnant trauma patient are a poor indicator of fetal well being and that 80% of pregnant females who survive hemorrhagic shock will experience fetal death. •Because of the mother’s expanded intravascular volume, maternal tachycardia and hypotension occur late in shock, often only after a 30% to 35% blood volume loss. An abrupt decrease in maternal intravascular volume results in a profound increase in uterine vascular resistance resulting in a reduction in fetal oxygenation despite normal maternal vital signs. •The pregnant woman will require more fluid resuscitation than the nonpregnant trauma patient in order to maintain an adequate circulating blood volume. With hemorrhage, otherwise healthy pregnant patients may lose 1200-1500 ml of their blood volume before exhibiting signs and symptoms of hypovolemia. In shock states, the placenta is a non-essential organ. •Monitoring of CVP response to fluid challenges may be valuable in maintaining the relative hypervolemia required in pregnancy. •If a pericardiocentesis is required, the pericardial needle puncture should be above the fundal level, particularly after it reaches the height of the xiphoid near the 36th week of pregnancy. 15 •If a pregnant patient develops seizures following an injury it may be difficult to ascertain if the seizures are secondary to a head injury or a complication of late pregnancy called eclampsia. •Signs and symptoms of a closed head injury include hypertension, alteration in level of consciousness, pupillary changes, and bradycardia. •Signs and symptoms of eclampsia that are not typically found in trauma patients are hyperreflexia, proteinuria, and peripheral edema. •Hypertension is not a normal finding in any pregnant patient. •Magnesium sulfate may be required for treatment of eclampsia. •(picture from previous version) 16 •A thorough abdominal exam should be performed, assessing for pain, tenderness, rigidity, guarding, and easily palpable fetal parts that may indicate uterine rupture. •Abruptio placentae may be suggested by vaginal bleeding (70% of the cases), uterine tenderness, frequent uterine contractions, uterine tetany, or uterine irritability. • Fetal heart tones can be ausculatated with a doppler ultrasound at 10 weeks. External fetal monitoring by cardiotocographic monitoring at 22-24 weeks gestation. If it is not available during transport, the FHR should, at a minimum, be monitored by doppler no less than every 15 minutes. Document fetal movement and any contractions. An abnormal fetal heart rate over 160 or under 120 beats per minute is a very sensitive indicator of fetal distress, hypoxia, and maternal volume status. •Fetal monitoring should be initiated to trend changes in fetal heart rate as well as variability, decelerations, and absence of accelerations. Variability is the beat-to-beat irregularity of the fetal heart rate; it is the single most important factor in predicting fetal well being. Decreased variability may be precipitated by fetal hypoxia, as a hypoxic fetus with metabolic acidosis is unable to accelerate the heart rate. Decelerations can occur with contractions or with cord compression. Decelerations will be noted on the EFM with contractions as the blood is restricted to the placenta. The infant has no reserve and becomes bradycardic due to the acidosis and placental insufficiency. Late decelerations always mean there is placental insufficiency. Signs of fetal decompensation include back-to-back decelerations, loss of variability, lack of spontaneous accelerations, tachycardia, and subtle decelerations. 17 •As soon as the primary assessment and management of both mother and fetus are complete, the woman’s health and prenatal history should be ascertained, along with information surrounding the present injury. The maternal secondary survey should follow the same pattern as in the nonpregnant patient. Remember that the goal should be rapid transport to a tertiary care center that can care for both mother and fetus. •Evaluate the uterine contour, palpate for any uterine tenderness, and note the presence of any contractions. The stretched peritoneum from the gravid uterus causes decreased sensitivity of the nerve endings making the physical exam much less reliable. Visual inspection of the perineum and vagina for evidence of bulging, crowning, presentation of fetal parts, bleeding, and amniotic fluid should be completed. •Fundal height should be measured in centimeters from the symphysis to the fundus. The fundal height roughly correlates to the gestation of the pregnancy in weeks. A quick estimation of gestational age is the centimeter measurement along the midline from the symphysis pubis to the fundus, which approximates the gestational age in weeks. At 20 weeks gestation the fundus is usually at the level of the umbilicus. (no copyright issues, ok to use, Leslie Lewis) 18 •Almost 9/10 cases of trauma in pregnancy are minor. •Even with minor trauma the pregnant woman should be questioned about seat belt use and placement, loss of consciousness, abdominal pain, vaginal bleeding, premature rupture of the membranes, and fetal activity. •Minor trauma to flank/abdomen warrants a minimum of 4 hours of monitoring to include fetal monitoring. •Eighty percent of all pregnant women who present to the hospital in hemorrhagic shock survive but have an adverse fetal outcome. •(x-ray from previous version) 19 Next slides will cover these topics. Don’t discuss in detail here. 20 •The most common obstetric problem caused by trauma is uterine contractions. Evaluate strength of contractions: feel tip of nose = mild; feel chin = moderate; forehead = strong. •Preterm labor should be suspected if the patient has contractions 10 minutes apart or less for a period of 1 hour or longer. •Tocolytics should be given only after uteroplacental injury has been ruled out and after fluid resuscitation and oxygenation has been provided. •Preparation for an imminent delivery and the resuscitation of a potentially distressed infant is imperative if contractions continue without resolution. •(picture courtesy of Karen Snider/Elisabeth Able) 21 •Abruptio placentae is placental separation from the uterus. This as an obstetrical life-threatening emergency. •The best indicators of placental separation are clinical assessment. •Signs and symptoms: vaginal bleeding, uterine tenderness and irritability, leakage of amniotic fluid, maternal hypotension, a uterus larger than normal for gestational age, and a change in FHR. •Thirty percent of abruptions following trauma may not exhibit vaginal bleeding. Abruptio placentae can occur for up to 72 hours after even minor trauma. •In most cases of uterine rupture or abruptio placentae, the patient will complain of abdominal pain or cramping. •Disseminated intravascular clotting (DIC) can occur. If this occurs, replacement of fibrinogen, fresh frozen plasma and platelets must be administered immediately. Definitive treatment is uterine evacuation. •(illustration courtesy of Karen Snider) 22 •Suggestive mechanism: direct blow, perforation, or compression injury, or when previous uterine surgery, including Cesarean section has taken place. •S/Sx: abdominal tenderness, guarding, rigidity, or rebound tenderness, especially if there is profound shock. Also, abnormal fetal lie, easy palpation of extrauterine fetal parts, and inability to palpate readily the uterine fundus. •In order to save the mother, immediate laparotomy needs to be performed. Maternal mortality from uterine rupture is approximately 10% while fetal mortality exceeds 70%. •(picture from previous version) 23 •If the pregnant woman reports release of vaginal fluid or if fluid is observed in the vagina, rupture of membranes should be suspected and should prompt additional evaluation. The use of nitrazine paper can be a quick and reliable test to check for ruptured membranes. Amniotic fluid is alkaline and will have a pH of 7.0 to 7.5 as indicated by a blue color on the nitrazine paper. Vaginal fluid is more acidic and has a pH of 5.0, which will change the color of the nitrazine paper to red. •Fetal-maternal hemorrhage affects 8 to 30% of all pregnant trauma patients. In cases of Rh incompatibility, the fetus is Rh positive and Mom Rh negative. If some fetal red blood cells leak into the maternal circulation system, the mother may produce antibodies to the Rh D factor (Rh sensitization). This isoimmunization produces a hemolytic anemia in the fetus. To prevent this, immunoglobulin therapy should be instituted within 72 hours of injury (Rhogam). 24 •Limited data exists to support prehospital peri-mortem C-sections. •The C-section must be performed within four minutes of maternal loss of pulses, and the infant must be delivered by the fifth minute. •Fetal survival depends upon the age of the fetus and time without oxygen or maternal circulation. Longer down times are associated with an increased incidence of neurological sequelae. •Of the over 200 successful cases of peri-mortem C-sections, reported in the literature, there was no fetal survival when the gestational age was less than 26 weeks. (no copyright issues, ok to use, Leslie Lewis) 25 Maternal survival is key. Pregnancy does not change priorities! 26 (picture courtesy of Michel Wolford Hall) 27