Transcript Acute Abdomen in Pregnancy

Acute Abdominal Pain in Pregnancy:
Diagnosis and Management
Conservative vs. Surgical
Andrea Lausman MD, FRCSC
Maternal Fetal Medicine Specialist
St. Michael’s Hospital
University of Toronto - Assistant Professor
March 19, 2013
Objectives
1. History, Physical, Investigations:
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How they differ in pregnancy
2. Differential Diagnosis of acute abdominal pain
3. Diagnostic Imaging: US/ CT/ MRI
4. A review of some of the more common causes of acute
abdomen in pregnancy
5. In the Operating Room
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Laparoscopy vs. Laparotomy
Issues specific to pregnancy
Scope of the Problem
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Definition of Acute Abdomen:
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S&S of intra-peritoneal disease best treated surgically
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~1/500 women need non-obstetrical abdominal
surgery during pregnancy
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Most common non-obstetrical surgical emergencies:
1.
2.
3.
4.
5.
Acute appendicitis
Cholecystitis
Intestinal Obstruction
Pancreatitis
Trauma
• “Earlier diagnosis means better prognosis”
Sir Zachary Cope 1921
• Weigh risks and benefits of diagnostic
modalities and therapies for both mother
and fetus
History
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P – Pain: onset, duration, intensity, character
Q - Quality
R – Radiates
S – Severity
T - Time
• Gestational age
• Associated symptoms – All frequent in normal pregnancy :
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Nausea & vomiting
Constipation
Increased frequency of urination
Pelvic / Abdominal discomfort
Physical
• Peritoneal signs are often absent in pregnancy
– lifting and stretching of the anterior abdominal wall
– underlying inflammation has no direct contact with the parietal
peritoneum
– precludes muscular response or guarding that is expected
• The uterus can obstruct and inhibit the movement of the omentum to
an area of inflammation
• < 24 weeks – document FHR
• >24 weeks - A reassuring tracing allows the evaluation to continue
at an appropriate pace
• Monitoring for contractions:
– Throughout the evaluation period
– After definitive treatment
Investigations
• Labs:
– ↑WBC (T2 <16, T3 <20-30 in early labour)
• Ultrasound
• CT
• MRI
Ultrasound
• Safe
• Relatively high sensitivity and specificity
• Test of choice for most ob/gyn causes of abdo
pain
• Also useful first line test for many non-gyne
conditions
Risk of Ionizing Radiation
• Risk based on gestational age and radiation dose
– 1 rad = 1 cGy
• First trimester: all or nothing phenomenon
• Most sensitive time for CNS teratogenesis is 10-17 wks
• In T2 and T3 – risk is childhood haematologic
malignancy
– Background risk is 0.2-0.3% of childhood cancer and leukemia –
Increased risk by 0.06% per rad of exposure
• No single study should exceed 5 rads
• Accepted cumulative dose of ionizing radiation in
pregnancy is 5-10 rads
Procedure
Chest radiograph (2 views)
Fetal
Exposure
0.02-0.07 mrad
Estimated Fetal Exposure from Some Common Radiologic Procedures
Abdominal film (single view)
100 mrad
Intravenous pyelography
>1 rad*
Hip film (single view)
200 mrad
Mammography
7-20 mrad
Barium enema or small bowel series
2-4 rad
CT scan head or chest
CT scan abdomen and pelvis
3.5 rad
CT pelvimetry
250 mrad
MRI
• Safe in pregnancy for mother or fetus
• Becoming standard of care for investigation of
placental implantation abnormalities, and further
delineation of fetal anomalies
• Issue is contrast media
CLINICAL PRACTICE – March 2006
• Canadian Family Physician; Motherisk Update
• Safety of gadolinium during pregnancy
Garcia-Bournissen F, Shrim A, Koren G
There is no evidence that
points to Gadolinium being
unsafe in pregnancy although no
centres in Canada use Gd in
pregnancy
Differential Diagnosis
Acute Abdomen
in
Pregnancy
Pregnancy
Related
Gyne
Adnexal
Accident,
fibroid
Degeneration…
Non-Gyne
GI
GU
Vascular
Difficult Diagnosis
• Expanding uterus dislocates other intraabdominal organs
• High prevalence of nausea, vomiting and
abdominal pain in pregnancy
• General reluctance to operate in
pregnancy
Treatment
• Conservative…
• Surgical
– Laparoscopy
– Laparotomy
• Obstetrical issues:
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Preterm labour
Intra-op monitoring
Tocolysis
Paeds
Delivery
Appendicitis
Appendicitis
• Most common non-obstetric cause of surgical emergency in
pregnancy
• Incidence: 1 in 500-2000
• Pregnancy does not affect the overall incidence of
appendicitis, but severity may be increased in pregnancy
• Appendicitis more common in T2 (40% of cases)
• Majority present with classic RLQ pain
• 25% of pregnant women will perforate
– Don’t delay O.R. >24 hrs, ↑ perforation rate from 0% to 66%
– Perforation occurs 2x more often in the T3 than T1,2
History
• Most reliable symptom is RLQ pain
• Nausea is present in nearly all cases
• Vomiting present in two thirds of patients
• Anorexia is present in only 1/3 – 2/3 of pregnant
patients, while it is present almost universally in
Non-pregnant patients
Physical
• Direct abdominal tenderness most common
– T1: Tenderness well localized in RLQ
– T2, T3: tenderness may change location: right periumbilical area,
RUQ, diffuse
• Classic Signs:
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Rebound present in 55-75% of patients
Abdominal muscle rigidity in 50-65%
Psoas sign observed less frequently in pregnancy
The Rovsig sign as frequent in pregnancy as non-pregnancy
state
• Rectal tenderness is usually present, particularly in the first trimester
• Fever and tachycardia are variably present; not sensitive signs
• Uterine activity due to localized peritonitis is common
Investigations
• US is imaging of choice
– Accuracy is greatest in T1; in T2 and T3 up to
40% normal appendix rate
• General Laboratory Investigations:
– Elevated WBC
– Neutrophils often >80%
– Urinalysis: Pyuria is observed in 10-20%
Treatment
• Surgical: Laparotomy or laparoscopy
• If the appendix appears normal remove it because:
(1) Early disease may be present despite its grossly
normal appearance
(2) Diagnostic confusion can be avoided if the condition
recurs
Laparotomy Incision
– Right mid-transverse incision directly over the point of
maximal tenderness vs. Lower abdominal midline
incision to accommodate unexpected surgical findings
and the possibility of the need for cesarean delivery
• Tilt the operating table 30° to the patient's left
Acute appendicitis and Diffuse
Peritonitis (Perforation)
• Cefuroxime, ampicillin, metronidazole, oxygen
pre-op
• Depending on G.A. consider CS as fetal loss
rate up to 20-36%
• Pre-op intubation and ventilation in cases of
hypovolemia
• Copious irrigation and use of intra-peritoneal
drain
Morbidity
• Perforation and abscess formation are more likely to
occur in pregnant patients
• The rate of generalized peritonitis relates directly to the
interval of time from symptom onset to diagnosis
• Maternal and fetal morbidity and mortality rates increase
once perforation occurs
• Fetal mortality is dependant on if perforation is present:
20-35% vs. 1.5% is no perf
• PTL/PTD is common – 5-14%, up to 50% in T3
• Maternal mortality should be <1%
Acute Cholecystitis
Acute Cholecystitis
• Incidence in pregnancy is 1:600-1:10,000
• Second most common cause of acute abdomen
in pregnancy
• Cholelithiasis is the cause in 90% of cases
• Incidence of cholelithiasis in pregnant women
having routine OB scans is 3.5-10%
History and physical examination
• Previous history; dyspepsia, intolerance of fatty foods
• RUQ/ mid-epigastrium pain; may radiate to the back
• Nausea & Vomiting ~ 50% of cases
• Fever occasionally
• Direct tenderness usually present in RUQ, Rebound
tenderness is rare
• Cholecystitis can mimic appendicitis in the third trimester
Investigations
• Blood tests are of limited value
– ↑ WBC, ↑ ALP – normal in pregnancy
– AST/ALT may help distinguish cholecystitis
from hepatitis
– Amylase elevated transiently ~1/3; high
amylase suggests pancreatitis
– Lytes: if persistent vomiting
Investigations
• Ultrasound is diagnostic
– Gall bladder calculi: present in> 95% with
acute cholecystitis
– Wall thickening >3mm
– Pericholecystic fluid
– Sonographic Murphy’s sign
– Dilation of intra and extra-hepatic ducts in
common bile duct obstruction
• If a radionucleotide scan of the gallbladder is
needed, the radiation dose is not prohibitive
Treatment
• Supportive: Intravenous fluids, Nasogastric suction
Non-surgical Management increases risk of:
• Recurrence in pregnancy if episode occurs:
– T1 92%
– T2 64%
– T3 44%
• Gallstone pancreatitis ~13% (Fetal loss rate 10-60%)
• ↑ SA, ↑PTL, ↑PTD
• A percutaneous drainage procedure may be indicated in select
patients in order to defer definitive surgery
Surgical Management
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Has been source of much controversy
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Recently immediate surgical management is used more
widely because:
1. Reduced use of medications
2. Recurrence rate in pregnancy is 44-92%, depending on
trimester
3. Shorter hospital stay
4. ↓ risk of developing life-threatening complication: perforation,
sepsis, peritonitis
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“Laparoscopy or laparotomy – depends on GA and
surgeon skill”
Choledocholithiasis
• 1/1200 patients require intervention
• ERCP uses 2-12 rads…
ERCP:
• Risk of bleeding = 1.3%
• Risk of pancreatitis = 3.5%
• Options are common bile duct exploration at time of
laproscopic cholecystectomy or ERCP followed by
cholecystectomy – no studies comparing the two
Bowel Obstruction
Bowel Obstruction
• Third most common cause of acute abdomen in
pregnancy: 1:1500 – 1:16,000
• Etiology:
1. Adhesions – 60-70% of cases
2. Volvulus ~25% of cases (much higher than non-pregnant)
• Risk of cecal volvulus is highest at times of rapid changes in
uterine size (16-20 wks, and 32-36 wks)
• Any redundant or abnormally mobile cecum is raised out of the
pelvis and allows for rotation around a fixed point
• Small bowel volvulus is more common in T3 and PP
3. <5% of time: Intussusception, incarcerated hernia, cancer,
diverticulosis etc.
History
• Crampy abdominal pain ~90%
– Constant or periodic, mimicking labor
– Pain may radiate to the flank, imitating pyelonephritis
– The severity of pain may not reflect the severity of
disease
• Vomiting
• Obstipation
Physical findings
• Classic distended tender abdomen with high-pitched
bowel sounds is the exception in pregnancy
• Uterus/cervix/adnexa share the same visceral
innervation as the lower ileum, sigmoid colon and rectum
- separating GI and Gyn sources of pain is often difficult
• Abdominal tenderness may be absent
• Bowel sounds are often normal upon presentation
• A tender cystic mass can sometimes be palpated
• Rebound tenderness, fever, and tachycardia occur late
in the course
Laboratory Studies
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Leukocytosis may be present
Electrolyte abnormalities
Hemoconcentration
Elevated serum amylase levels
• X-Ray
– Abdominal Plain film - best initial study
– Sequential films may be needed
– Air-fluid levels, progressive bowel dilation
Treatment
Conservative
• Fluid and electrolyte replacement
• NG suction
• Enema
Surgical
• Midline abdominal incision
• Decompress the bowel
• Relieve obstruction
• Resect nonviable tissue
Prognosis
• Maternal Mortality ~6%
• Fetal mortality ~26%
• Bowel strangulation requiring resection ~23%
Pancreatitis
Pancreatitis
• 1:1000 – 1:3000 pregnancies
• Usually late in T3, or PP – may be due to increased
intra-abdominal pressure on the biliary ducts
• Etiology
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Cholelithiasis – 67-100% of cases
Abdominal surgery
Blunt abdominal trauma
Infection
Penetrating duodenal ulcer
Hyperparathyroidism
Hyperlipidemic pancreatitis
• Associated with pregnancy
– Preeclampsia – damage to microvasculature
– AFLP
History
• Sudden, severe epigastric pain radiating to
the back
• Postprandial nausea and vomiting
• Fever
Physical
• Patient in the ‘fetal position’ – due to severe pain
• Hypoactive bowel sounds (paralytic ileus)
• Jaundice
• Epigastric tenderness is the most reliable physical
finding
• Peritoneal signs are minimal or absent
• Pulmonary findings in ~10% - can lead to ARDS
Laboratory Studies
• Amylase
– During normal pregnancy, amylase levels are slightly elevated
• Lipase – better predictor than amylase
• Hyperglycemia
• Hyperbilirubinemia
• Hypocalcemia
• Hemoconcentration
• Electrolyte abnormalities
• Ultrasound of the upper abdomen
Ranson’s Criteria
On Admission:
At 48 hours After Admission:
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Age > 55
WBC > 16
Glucose > 10
LDH > 350
AST > 250
Hct drop > 10%
BUN increase > 1.79
Ca < 2
Arterial pO2 < 60
Base deficit (24 - HCO3) > 4
Fluid needs > 6L
Prediction of Mortality
• <5 – 15%
• 5-9 40%
• >9 100%
Treatment
• Bowel rest – npo, NG suction, IV fluids
• Fluid/electrolyte resuscitation
• Analgesics:
– demerol doesn’t cause spasm of sphincter of Oddi
• Anti-spasmodics
• Antibiotics if fever or sepsis is present
• ERCP, endoscpic sphincterotomy can be used to treat
gallstone pancreatitis
• Surgery for refractory cases
Prognosis
• Acute symptoms last for ~6 days
• Maternal mortality rate ranges from 0-37%
• Perinatal mortality rate is ~ 10%
• The risk of perinatal death increases with
the severity of disease
Trauma in Pregnancy
Trauma in Pregnancy
• Occurs in 6-7% of pregnancies
• Penetrating
– Gunshot wounds
– Stab wounds
• Blunt trauma
– MVA
– Physical abuse, Sexual Abuse
– Accidental Falls
Maternal Injury
• Gravid uterus changes the location of abdominal
organs
• 25% of pregnant women with blunt trauma will
have hemodynamically significant hepatic or
splenic injuries due to increased vascularity
• In penetrating trauma maternal death rate is
lower than non-pregnant (~3.9% vs 12%)
because the uterus ‘protects’ intra-abdominal
organs
• Uterine rupture: most often at the fundus
Fetal Injury
• Direct fetal injury occurs in <1% of blunt trauma
• Direct fetal injury occurs in up to 90% of blunt trauma
• Fetal skull and brain injury more common in T3 when the
head is engaged in the pelvis
• Deceleration injury to the fetal had can also occur
• Most common cause of fetal death is maternal death
• Fetal mortality 3-38%: abruption, shock, maternal death
Placental Abruption
• CTX > thAn 1 in 10 minutes is associated with 20% risk of
diagnosed placental abruption
• Initiate CTG monitoring asap at >24 weeks; at least 4-6 hrs
• Risk of abruption exists for several days post-trauma
• Up to 40% of severe MVA’s are associated with abruption
• Minor trauma can result in abruption in 2-3%
• 10-30% of trauma victims have evidence of feto-maternal
hemorrhage
Management
• ABC’s
• Rapid maternal respiratory support
• Evaluate the fetus once mother is stable: CTG
• Left lateral decubitus
• US
• Fetal monitoring for at least 4 hrs,then prn
• Surgical exploration prn +/- CS
ATLS in Pregnancy
Surgical Management
• Exploratory Laparotomy
• Delivery of fetus if direct uterine injury
or fetal injury
Prevention Techniques
• Seat Belts
• Airbags
Gynecologic Causes of Acute
Abdomen: Adnexal Masses
• Incidence in Pregnancy = 2%
• Most are functional cysts
• Expectant Mgmt for those <6cm
– 82-94% resolution
• Torsion:
– ~4% of adnexal masses will tort
Adnexal Torsion
• Pregnancy predisposes to adnexal torsion
• 1 in 5 adnexal torsions occurring during
pregnancy
• Associated with an ovarian mass in 50-60% most often a dermoid
• Occurs on R > L, by a ratio of 3:2
• Occurs most frequently in the first trimester
Treatment
• Surgical
• Conserve as much ovarian tissue as possible
• If the tissue is necrotic - unilateral salpingo-oophorectomy
• Partial torsion:
– Conservative management - Untwist the pedicle, remove the cyst,
and stabilize the ovary
• If removal of the corpus luteum is necessary prior to 10
weeks of gestation needs progesterone supplementation
In the Operating Room
Pre-Op Decision Making
• Laparoscopy has the same indications as the
non-pregnant patient
• Approach is based on skill of surgeon and
availability of staff/ equipment
• Benefits of Laparoscopy:
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↓ post-op pain
↓ post-op ileus
↓ LOS
Faster return to work
Concerns r.e. Laparoscopy
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Trocar insertion
CO2 insufflation
Technical ability to get exposure
Altered physiology of pneumoperitoneum
Decreased venous return
• Can be used in all trimesters
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With increasing experience with this technique, there are fewer barriers
Reports of successful appendectomy and cholecystectomy in the third
trimester
Benefits in the Pregnant Patient
• ↓ fetal depression due to less narcotic use
• ↓ risk of wound complications
• ↓ post-op maternal hypoventilation
• ↓ risk of VTE due to early mobilization
• ↓ uterine irritability leads to less SA and PTL
Technical Issues
• Patient positioning
– Left lateral decubitus
• Initial Port Placement
– Hassan/ Verres, Optical trocar – adjust location to fundal height,
previous incisions and experience of surgeon
• Place trocars under direct visualization according to
fundal height
• Insufflation to 10-15mmHg
– No evidence of long-term detrimental effects of CO2
pneumoperitoneum
• Intra-op CO2 monitoring should be used
– Theoretical risk of fetal acidosis due to
pneumoperitoneum; has been seen in animal studies,
but not documented in the human fetus
• VTE Prophylaxis (pneumoperitoneum increases
venous stasis)
– Intra-op/ Post-op pneumatic compression stockings
– Early post-op ambulation
Peri-Operative Care
• Obstetrical Consultation
• Fetal Heart Rate Monitoring – pre and
post-op documentation of FHR / NST
• Tocolytics
– No literature supports prophylactic use of tocolytics
– Consider if S&S of PTL
– Need OB consult for meds/ dosing etc
Conclusions
• Laparoscopy is safe in all trimesters of
pregnancy
• The Veress needle can be used – depends on
surgeon experience with ‘alternate site’ entries
• Pressure of 12-15mmHg – less than uterine ctx.
• Laparoscopy decreases maternal morbidity,
LOS, fetal depression (due to less narcotic use)
Summary
• The incidence of acute abdominal pain in
pregnancy which requires surgery is ~1/500
• It is important to keep a broad differential
diagnosis as signs, symptoms and investigations
can all altered due to pregnancy
• Diagnostic Imaging is safe in pregnancy
• Surgical options include laparotomy and
laparoscopy