Acute Abdomen in Pregnancy

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Acute Abdomen in Pregnancy

• Kate Pettit, MS III
• June 18, 2007

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The Most Important Equation



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How old are your prospective pregnant patients?
Avg Age at First Birth in US 25.1 yrs
Live Births per 1,000 Women
CDC 2004
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DDx of Abdominal Pain in Pregnancy

• Divided into three categories
• 1) Conditions incidental to pregnancy
• 2) Conditions associated with pregnancy
• 3) Conditions due to pregnancy

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Conditions Incidental to Pregnancy

• Acute appendicitis
• Acute pancreatitis
• Peptic ulcer
• Gastroenteritis
• Hepatitis
• Bowel obstruction
• Bowel Perforation
• Herniation
• Meckels Diverticulitis
• Toxic megacolon
• Pancreatic pseudocyst
• Ovarian cyst rupture
• Adnexal torsion
• Ureteral calculus

• Rupture of renal pelvis
• Ureteral obstruction
• SMA syndrome
• Thrombosis/infarction
• Ruptured visceral artery aneurysm
• Pneumonia
• Pulmonary embolus
• Intraperitoneal hemorrhage
• Splenic rupture
• Abdominal trauma
• Acute intermittent porphyria
• Diabetic ketoacidosis
• Sickle Cell Disease

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Conditions Associated with Pregnancy

• Acute pyelonephritis
• Acute cystitis
• Acute cholecystitis
• Acute fatty liver of pregnancy
• Rupture of rectus abdominus muscle
• Torsion of pregnant uterus

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Conditions Due to Pregnancy

• Ectopic pregnancy
• Septic abortion with peritonitis
• Acute urinary retention due to retroverted uterus
• Round ligament pain
• Torsion of pedunculated myoma
• Placental abruption
• Placenta percreta
• HELLP Syndrome
• Acute Fatty Liver of Pregnancy
• Uterine rupture
• Chorioamionitis

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Ectopic Pregnancy

• Classic Symptoms
• Abdominal pain
• Amennorrhea
• Vaginal Bleeding
• Diagnosis
• Transvaginal U/S (TVS)
• Presence of a true gestational sac at 4.5 to 5
  wks is the 1st sign of IUP.
• Cardiac activity is first detected at 5.5 to 6
  weeks.
• Serum quantitative HCG
• Absence of an intrauterine gestational sac at hCG
  concentrations gt1500-2000 IU/L suggests an
  ectopic or nonviable intrauterine pregnancy

• Management
• Option of medical vs surgical management if pt is
  hemodynamically stable and no rupture has
  occurred.
• Emergent surgical management if rupture has
  occurred and/or patient is hemodynamically
  unstable
• Prognosis
• Ruptured ectopic pregnancies account for 4-
  10 percent of all pregnancy related deaths.

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HELLP SyndromeHemolysis Elevated Liver Enzymes
Low Platelets

• Incidence 1 in 1K pregnancies
• Timing Majority diagnosed at 28-36 wks
• Labs ?Plts, ?AST/ALT, ?indirect bili,
  ?haptoglobin, schistocytes on peripheral Smear
• Management
• Emergent delivery for pregnancies gt 34 weeks,
  nonreassuring fetal status, severe maternal
  disease (multiorgan dysfunction, DIC, liver
  infarction or hemorrhage, ARF, or abruptio
  placenta)
• Delayed delivery in stable pregnancies lt34 wks
  after administration of corticosteroids

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Acute Fatty Liver of Pregnancy

• Incidence Rare (1 in 7K 16K deliveries)
• Timing 2nd half of pregnancy (usually 3rd tri)
  Sxs N/V (75), epigastric abdominal pain (50),
  anorexia, jaundice /- signs of pre-eclampsia
• Labs ?PT, ?PTT, ?AST/ALT, ?Cr, ?glucose, /-
  ?WBC, /- ?Plts
• Tx Maternal stabilization (glucose infusion,
  reversal of coagulopathy) and emergent delivery

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Definition of Acute Abdomen

• Stedman's Medical Dictionary, 27th Edition
  defines acute abdomen as "any serious acute
  intra-abdominal condition attended by pain,
  tenderness, and muscular rigidity, and for which
  emergency surgery must be considered.

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Epidemiology

• Incidence of acute abdomen during pregnancy is 1
  in 500-635
• 1 Acute Appendicitis
• 2 Acute Cholecystitis

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Challenges of Diagnosis

• Symptoms
• Nausea, vomiting, and abdominal pain are common
  in the normal obstetric population. N/V are most
  common in weeks 4-16.
• Physical Exam
• Expanding uterus dislocates other intraabdominal
  organs.
• Labs
• Leukocytosis (10-20K) and anemia are common in
  normal pregnancies and thus, not as predictive of
  infection or blood loss.

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Which conditions require urgent surgical
management in pregnancy?

• Trauma
• Acute appendicitis
• Intestinal obstruction
• Perforated duodenal ulcer
• Spontaneous visceral rupture
• Ectopic pregnancy
• Ovarian or uterine torsion

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Timing of Surgery

• 1st trimester (wks 1-12)
• 12 SAb rate
• 2nd trimester (wks 13-26)
• 0 - 5.6 SAb rate
• 5 rate of preterm labor
• 3rd trimester (wks 27-40)
• 30-40 rate of preterm labor

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Imaging Options

• U/S No known adverse effects.
• X-ray Presence of adverse effects depends on
  total radiation dose.
• CT Presence of adverse effects depends on total
  radiation dose.
• MRI No known adverse effects.
• ERCP Only recommended for therapeutic use, not
  for routine imaging.

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Radiation during pregnancy
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Use of ERCP in PregnancyAmerican Society for
Gastrointestinal Endoscopy Guidelines

• ERCP should only be used when therapeutic
  intervention is intended (usually for biliary
  pancreatitis, choledocholithiasis, or
  cholangitis).
• Several studies have confirmed the safety of ERCP
  in pregnancy.
• With precautions, fetal exposure is well below
  the 5- to 10-rad level.
• Kahaleh et al. reported an estimated fetal
  radiation exposure of 40 mrads (range 1-180
  mrad).
• Precautions for reducing radiation exposure
• Lead shields placed under the pelvis and lower
  abdomen, remembering that the x-ray beam
  originates from beneath the pt.
• Use of brief ''snapshots'' of fluoroscopy to
  confirm cannula position and CBD.
• Minimize total fluoroscopy time.

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Reducing Radiation in Pregnancy

• X-ray PA exposures lowers the radiation dose by
  2 to 4 mrad compared with the traditional AP
  exposures because the uterus is located in an
  anterior pelvic position.
• CT Narrow collimation and wide pitch (the
  patient moves through the scanner at a faster
  rate) results in a slightly reduced image
  quality, but provides a large reduction in
  radiation exposure.

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Sequelae of Radiation in Pregnancy

• May cause failure of implantation, malformation,
  growth retardation, CNS abnormalities, or fetal
  loss.
• Exposure lt10 rads (100 mGy) does not ? the risk
  of fetal death, malformation, or developmental
  delay.
• Highest risk of radiation damage during embryonic
  period of organogenesis (weeks 3-9).

International Commission on Radiological
Protection.
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Childhood Leukemia and Radiation

• The background rate of leukemia in children is
  about 3.6 per 10,000.
• Exposure to one or two rad increases this rate to
  5 per 10,000.

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Use of contrast in pregnancy

• Iodinated contrast
• Crosses the placenta
• Can produce transient effects on the developing
  fetal thyroid gland, although clinical sequelae
  from brief exposures have not been reported.
• May be used when indicated.
• Gadolinium
• Crosses the placenta.
• Because of limited experience with this agent,
  gadolinium is currently not recommended for use
  in the pregnant patient unless the potential
  benefit justifies the potential risk to the
  fetus.
• Animal studies have shown an ? risk of
  spontaneous abortion and skeletal and visceral
  anomalies.

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MRI as an imaging modality

• Mechanism
• Electromagnetic field induced changes in proton
  spin
• Theoretical risks to fetus
• Induction of local electric fields and currents
• Radiofrequency radiation results in heating of
  tissue

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American College of Radiology Paper on MRI Safety

• MRI should only be used in pregnancy when
• The information requested from the study cannot
  be obtained from nonionizing means.
• The information is needed to care for the pt and
  fetus during pregnancy.
• The ordering MD does not feel it is prudent to
  delay diagnosis until after pregnancy.

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MRI in Pregnancy

• No studies have shown adverse effects on the
  fetus or the outcome of the pregnancy.
• However, arbitrarily MRI is NOT usually performed
  in the 1st trimester 2/2 to this being the period
  of organogenesis.
• When MRI is used, informed consent must include
  the possibility that a previously undiagnosed
  fetal abnormality may be found.

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"No single diagnostic procedure results in a
radiation dose that threatens the well-being of
the developing embryo and fetus." -- American
College of Radiology
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Appendicitis

• 1 Cause of Acute Abdomen

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Appendicitis

• Accounts for 25 of the operative indications for
  non-obstetric surgery antepartum.
• Appendicitis is NOT more common during pregnancy.
• Incidence is approximately equal in all three
  trimesters.

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Signs and Symptoms

• RLQ pain Most reliable sx
• Anorexia and vomiting Not sensitive nor
  specific.
• Direct RLQ tenderness 100
• Rebound tenderness 55-75 of pts
• Abdominal muscle rigidity 50-65 of pts
• Psoas sign Observed less frequently.
• All findings are less common in 3rd trimester due
  to laxity of abdominal wall muscles.

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Adler Sign

• If the point of maximal tenderness shifts
  medially with repositioning on the left lateral
  side, the etiology is generally adnexal or
  uterine (vs appendiceal).

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Appendiceal Location

• Historically, many references have reported
  appendiceal displacement.
• In 2003, a study by Hodjati et al showed that
  pregnancy did NOT change appendiceal location.
• Degree of displacement, if any, is likely due to
  different extents of cecal fixation.

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Laboratory Evaluation

• WBC Absolute number not reliable given
  leukocytosis of pregnancy.
• Differential ? levels of band cells can be
  reliable indication of infection.
• U/A Caution as 20 of pts have pyuria or
  hematuria with appendicitis due to extraluminal
  irritation of the ureter (rather than due to a
  UTI).

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1st Line Imaging for Appendicitis

• Graded compression U/S
• 80 sensitive non-perforating appendicitis
• 28 sensitive perforated appendicitis
• 3rd trimester accuracy is lower due to technical
  difficulties.

Doris et al (meta-analysis).
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2nd Line Imaging for Appendicitis

• CT
• 94 sensitivity
• 94 specificity

• MRI
• Up to 100 sensitivity
• 96 specificity
• No known adverse effects on fetus, but cost and
  availability may be prohibitive.

Values are from small study of 45 pregnant pts.
Fielding and Chin (2006).
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Risks for Mother and Fetus

• 66 risk of perforation if surgery delayed by gt24
  hrs from presentation.
• Negative laparotomy rates of up to 35 are
  considered acceptable in the pregnant population
  (vs 15 in non-pregnant population).
• Non-perforated appendix
• Fetal mortality of 1.5
• Perforated appendix
• Fetal mortality of 20-35
• Maternal mortality of 1
• 83 risk of preterm contractions due to localized
  peritonitis.
• In all cases, the rate of premature delivery is
  highest in the 1st week post-op.

Augustin and Majerovic (2006).
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Recommendations for Diffuse Peritonitis

• IV Cefuroxime, ampicillin, metronidazole, and
  oxygen pre-operatively.
• Immediate C-section can be considered, depending
  on gestational age of fetus.
• Preoperative intubation and ventilation in cases
  of fetal hypoxia.

Augustin and Majerovic (2006).
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Acute Cholecystitis

• 2 Cause of Acute Abdomen

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PathophysiologyHormones and biliary disease

• ?Estrogen in pregnancy ? ?
  cholesterol synthesis, ?hepatic cholesterol
  uptake, ?catabolism of cholesterol to bile acids
  ? Bile supersaturation
  cholesterol stones
• ?Progesterone in pregnancy ? ?bile stasis
  and ? GB contraction in response to CCK

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Epidemiology

• Cholelithiasis is the cause of cholecystitis in
  pregnant pts in 90 of cases
• Incidence of cholelithiasis in pregnancy is
  3.5-10
• Only 30-40 of pregnant pts with gallstones are
  symptomatic

Augustin and Majerovic (2006).
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Presentation and Diagnosis

• Symptoms Basically identical in pregnant and
  non-pregnant pts
• Labs ?Bilirubin, /- ?Transaminases, ? Alkaline
  phosphatase is non-specific as it is ? normally
  in pregnancy
• Imaging U/S has an accuracy of 95-98 of
  detecting acute cholecystitis and
  choledocolithiasis

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Initial Management of Cholecystitis

• IV hydration
• Bowel rest
• Pain control
• Antibiotics
• Fetal monitoring
• Nasogastric decompression if necessary

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Surgical Management of Cholecystitis

• Cholecystectomy is now recommended as the primary
  treatment for cholecystitis because of
• Recurrence rate during pregnancy of 44-92,
  depending on date of 1st presentation
• Reduced use of medications
• Shorter hospital stay and fewer hospitalizations
• Elimination of risk of subsequent gallstone
  pancreatitis
• Minimizing development of potentially
  life-threatening complications such as
  perforation, sepsis, and peritonitis

Augustin and Majerovic (2006).
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Other Indications for Cholecystectomy During
pregnancy

• Choledocolithiasis (after ERCP)
• Gallstone Pancreatitis
• Recurrent symptomatic cholelithiasis
• Several studies have found the incidence of SAb,
  preterm labor, or premature delivery to be higher
  in pts treated non-operatively than in those
  undergoing cholecystectomy.
• However, no prospective trial has been done to
  determine the best management for recurrent
  biliary colic.

Curet (2000).
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Laparotomy vs Laparoscopy?
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Choosing Surgical Technique

• Laparotomy
• Currently considered 1st line approach.
• Always preferred approach when diffuse
  peritonitis is present, as it is associated with
  a lower complication rate than laparoscopy in
  this setting.

• Laparoscopy
• First offered in 1991 for pregnant patients for
  appendectomy and cholecystectomy.
• Many new studies show this technique to be safe
  in pregnancy for routine appendicitis, especially
  during the 2nd trimester.
• Can help r/o salpingitis, adnexal mass, or
  ectopic pregnancy when dx is uncertain.

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Recommendations to improve safety of laparoscopy
during pregnancy

• Obstetrical consultation should be obtained
  preoperatively.
• When possible, operative intervention should be
  deferred until 2nd trimester.
• Procedure should be performed with pt in supine,
  left lateral decubitus position and degree of
  reverse Trendelenburg should be minimized.
• Open Hasson technique should be used to prevent
  puncture of uterus.
• Pneumoperitoneum pressures should be minimized to
  8-12 mm Hg with maximum 15 mm Hg.
• Administration of tocolytic agents and
  perioperative monitoring of fetal heart tones
  should be considered.
• Pneumatic compression devices should always be
  used as both pneumoperitoneum and the condition
  of pregnancy are a risk for venous stasis.

Halkik et al (2006).
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Optimizing Delivery

• Understanding what the consulting obstetrician
  is doing for your patients

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Use of Tocolytics for Preterm Labor

• Purpose
• Delay delivery so that corticosteroids can be
  administered.
• Prolong pregnancy when there are underlying,
  self-limited causes of labor, such as
  pyelonephritis or abdominal surgery, that are
  unlikely to cause recurrent PTL.
• Use is limited to lt34 weeks gestation

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Types of Tocolytics I

• Terbutaline (Beta-2 agonist)
• Mechanism Agonist at myometrium causing
  relaxation
• Meta-analysis showed ? of births within
  subsequent 48 hrs but no change in of births
  within subsequent 7 days
• Magnesium sulfate
• Mechanism Unknown, likely competes with calcium
  reducing myometrial contractility
• Cochrane review concluded that this drug did not
  significantly reduce the proportion of women
  delivering within 48 hrs.

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Types of Tocolytics II

• Nifedipine (Calcium channel blocker)
• Mechanism Directly blocks influx of Ca ions
• Meta-analysis showed ? of births within 48 hrs
  as compared to terbutaline as well as ? of
  births within subsequent 7 days.
• Indomethacin (Cyclooxygenase inhibitor)
• Mechanism Blocks production of prostaglandins
• Small studies indicate effectiveness for
  prolonging time to delivery

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Use of corticosteroids to improve fetal outcomes
in premature delivery

• Administration
• Two doses of 12 mg betamethasone IM given 24 hrs
  apart.
• Benefit of therapy is initially observed 18 hrs
  after the first dose with maximal benefit 48 hrs
  after the first dose.
• Benefits include reduction in the incidence of
• Neonatal respiratory distress syndrome
• Intraventricular hemorrhage
• Necrotizing enterocolitis
• Mortality

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Steroids and peritonitis?

• Glycocorticosteroids administered during the
  initial phase of experimental diffuse peritonitis
  display favorable action decreasing animal
  mortality rate regardless of the dose. However,
  glycocorticosteroids given in the developed
  septic syndrome decrease the pro-inflammatory
  cytokine serum concentration regardless of the
  dose, still not affecting the animal mortality
  rate.

Modzelewski et al (2002).
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References

• Acute Fatty Liver of Pregnancy. Up-to-date.
• Augustin, G and M Majerovic. Non-obstetrical
  acute abdomen during pregnancy. European J of
  Obstetrics, Gynecology, and Reproductive Biology
  2006 131 4-12.
• Brooks et al. The Pregnant Surgical Patient.
  ACS Surgery Principles and Practice.
• Curet, MJ. Special problems in laparascopic
  surgery previous abdominal surgery, obesity,
  and pregnancy. Surg Clinic North Am 2000 80
  1093-1110.
• Ectopic Pregnancy. Up-to-date.
• Fielding, JR and BM Chin. Magnetic Resonance
  Imaging of Abdominal Pain during Pregnancy. Top
  Magn Resonance Imaging 2006 17 409-416.
• Halkic et al. Laparascopic management of
  appendicitis and symptomatic cholelithiasis
  during pregnancy. Langenbacks Arch Surg 2006
  391 467-471.
• HELLP Syndrome. Up-to-date.
• Inhibition of preterm labor. Up-to-date.
• Kahaleh et al. Safety and efficacy of ERCP in
  pregnancy. Gastrointestinal Endoscopy 2004 60
  287-292.
• Modzelewski et al. Tests for the usefulness of
  glucocorticosteroids in treatment of experimental
  peritonitis. Pol Merkur Lekarski 2002 69
  228-231.
• Murray et al. Diagnosis and treatment of ectopic
  pregnancy. CMAJ 2005 73 905.
• Pedrosa et al. MR Imaging of Acute Right Lower
  Quadrant Pain in Pregnant and Nonpregnant
  Patients. Radiographics 2007 27 721-753.

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