01Approach to the Critical Patient/attcp40

Immediate priorities

›Surgical emergency recognition

›Non-reducible, tense, exquisitely tender hernia mass

›Absent cough impulse confirms incarceration

›Overlying skin erythema, induration, or crepitus — predictive of bowel ischemia

›Sepsis and perfusion threats

›Fever, tachycardia, hypotension — late and ominous signs

›Altered mental status suggesting septic shock

›Peritoneal signs

›Guarding, rigidity, or rebound tenderness

›Feculent vomiting indicating late obstruction

›Resuscitation priorities

›IV access and fluid resuscitation

›Two large-bore IVs

›Crystalloid bolus 1-2 L for hypovolemia or sepsis

›NPO immediately

›Nasogastric tube if bowel obstruction present

›Foley catheter for urine output monitoring

›Time-critical surgical referral

›Delays greater than 6 hours from onset significantly increase bowel resection risk

›Do NOT attempt manual reduction if strangulation is suspected

Monitoring and targets

›Hemodynamic and perfusion monitoring

›Continuous cardiac monitoring and pulse oximetry

›MAP target >= 65 mmHg

›Urine output target >= 0.5 mL/kg/hour

›Serial lactate measurement

›Lactate >= 2.0 mmol/L predictive of nonviable bowel

02History/hx60

Presentation pattern

›Core symptom complex

›Pain character

›Sudden onset, severe, constant pain at hernia site

›Persistent and progressively worsening — not colicky

›Not relieved by lying down or manual reduction

›Duration of symptoms

›Duration from onset is the most critical prognostic variable

›Risk of bowel resection increases significantly after 6 hours

›Associated gastrointestinal symptoms

›Nausea and vomiting

›Vomiting may become feculent in late obstruction

›Obstipation — cessation of flatus and stool

Hernia history

›Prior hernia characteristics

›Known hernia at this site

›Duration of known hernia

›Previously reducible vs always irreducible

›Prior hernia repair

›Type of repair performed

›Recurrent hernia after repair

›Episodes of prior incarceration

›Self-reduced vs manually reduced previously

›Duration of prior irreducible episodes

Risk factors

›Hernia type risk

›Femoral hernia — highest strangulation risk

›22% strangulation risk at 1 month

03Physical Exam/exam48

Vital signs and general appearance

›Hemodynamic stability assessment

›Tachycardia — HR > 100 bpm, early sign of pain or volume depletion

›HR > 120 bpm suggests significant compromise

›Hypotension SBP < 90 mmHg is a late ominous sign

›Fever — temperature >= 38.5 C suggests ischemia or perforation

›Hypothermia is a sign of septic shock

›Normal temperature does not exclude serious pathology

›General appearance

›Diaphoresis, pallor, and toxic appearance

›Indicates systemic compromise

›Escalate to resuscitation bay immediately

›Level of distress and ability to cooperate

›Altered mental status signals sepsis severity

Hernia site examination

›Local findings at hernia site

›Mass characteristics

›Tense, non-reducible, exquisitely tender

›Warmth and induration over the mass

›Overlying skin changes

›Erythema — predictive of bowel ischemia

›Crepitus — gas-forming organisms or perforation

›Discoloration or necrosis — late finding requiring emergent OR

›Cough impulse assessment

›Absent cough impulse confirms incarceration

›Present cough impulse suggests reducible hernia

Abdominal examination

›Peritoneal assessment

04Differential Diagnosis/ddx33

Life-threatening diagnoses

›Strangulated hernia with bowel necrosis

›ICD-10 K46.1 unspecified abdominal hernia with obstruction, without gangrene

›ICD-10 K46.0 unspecified abdominal hernia with gangrene

›Incarcerated hernia without strangulation

›ICD-10 K46.0 — irreducible but viable bowel

›May still require urgent operative management

›Bowel obstruction with perforation

›Pneumoperitoneum on imaging

›Peritoneal signs and septic shock

Mimics requiring urgent differentiation

›Testicular torsion

›Acute scrotal pain, high-riding testis

›Absent cremasteric reflex, no fever early

›Inguinal lymphadenopathy

›Tender nodes, infectious source identifiable

›No cough impulse, no bowel symptoms

›Groin abscess

›Fluctuant, erythematous, often associated with skin source

›No bowel obstruction symptoms

›Femoral artery aneurysm or pseudoaneurysm

›Pulsatile mass in femoral triangle

›Bruits on auscultation

›Hydrocele

›Transilluminates, non-tender

›Smooth oval shape without bowel sounds

Hernias with challenging diagnosis

›Obturator hernia

05Laboratory Tests/lt43

Infection and ischemia markers

›Complete blood count

›Leukocytosis WBC > 18.5 x 10^9/L — predictive of bowel resection

›Elevated neutrophil count

›Neutrophil-to-lymphocyte ratio > 6.5 — independent predictor of bowel resection

›Lactate

›>= 2.0 mmol/L predictive of nonviable bowel strangulation

›Strongest independent lab predictor of bowel resection

›Serial measurement every 2 hours if elevated

›C-reactive protein

›CRP > 10 mg/L associated with strangulation

›Limited acute specificity but supports clinical concern

›Creatine phosphokinase

›CPK elevation is relatively reliable early indicator of intestinal strangulation

›Trend useful when serial measurements available

Metabolic and organ function

›Comprehensive metabolic panel

›Electrolytes — correct derangements before surgery

›Hypokalemia and hyponatremia common with prolonged vomiting

›Metabolic alkalosis from gastric losses

›BUN and creatinine — dehydration and renal function assessment

›Antibiotic dosing adjustment based on GFR

›Contrast safety evaluation for CT

›Liver enzymes and bilirubin

›Elevated bilirubin may occur with necrosis

›LDH elevation correlates with ischemia

›Coagulation panel

›PT, INR, aPTT for surgical planning

06Diagnostic Tests/dt65

Scoring Systems

›Risk stratification tools for bowel viability

›No validated single score for strangulation prediction

›Clinical gestalt and laboratory combination used in practice

›ACEP Level C recommendation for combined clinical-biochemical assessment

›Laboratory-based risk predictors

›WBC > 18.5 x 10^9/L — independent predictor of bowel resection

›Lactate >= 2.0 mmol/L — strongest predictor of nonviable bowel

›NLR > 6.5 — predictive of bowel resection

›Clinical risk features for strangulation

›Skin overlying hernia changes — erythema, crepitus

›Duration > 24 hours from onset

›Femoral hernia type

›ASA physical status classification for surgical risk

›ASA I-II — low operative mortality

›ASA III-IV — significantly elevated mortality risk

›Comorbidity burden impacts disposition planning

MRI

›MRI role in strangulated hernia

›Limited acute utility

›Availability and time constraints preclude routine use

›Motion artifact in distressed patients

›Potential problem-solving indications

›Obturator hernia characterization when CT equivocal

›Complex pelvic anatomy in recurrent hernias

›Contraindications

›Hemodynamically unstable patients — CT preferred

›Non-MRI-compatible surgical hardware

CT

›CT abdomen and pelvis with IV contrast — gold standard

›Indications

›Diagnostic uncertainty regarding hernia type or strangulation

›Bowel obstruction without clinically obvious hernia site

›Obturator hernia or internal hernia suspected

›Key CT findings for strangulation

›Reduced or absent bowel wall enhancement — 56% sensitivity, 94% specificity

›Closed-loop obstruction pattern

›Mesenteric haziness and edema

›Mesenteric fluid — absence reliably rules out strangulation (negative LR 0.16)

›Advanced CT findings of nonviable bowel

›Pneumatosis intestinalis — gas within bowel wall

›Portal venous gas — ominous, often irreversible ischemia

›Free air indicating perforation

›Diagnostic accuracy combination

›Reduced wall enhancement + closed-loop + diffuse mesenteric haziness — AUC 0.91 for strangulation

›Spontaneous hyperattenuation of bowel wall on non-contrast CT characteristic of strangulated SBO

›Limitations

›IV contrast needed for wall enhancement assessment

›Renal function assessment prior to contrast

›Imaging may be unnecessary when clinical diagnosis is clear and patient requires immediate surgery

Ultrasound

›Point-of-care ultrasound (POCUS) for hernia

›Hernia identification

›Non-compressible, aperistaltic bowel loops in hernia sac

›Free fluid within the hernia sac — associated with ischemia

›Color Doppler assessment

›Absent color Doppler flow in entrapped mesentery or bowel wall

›Reduced flow compared with contralateral side

›Advantages of POCUS

›Rapid, no radiation, available at bedside

›Useful in pediatric and pregnant patients

›Can differentiate hydrocele from incarcerated hernia

›Limitations of ultrasound

›Operator-dependent accuracy

›Overlying bowel gas may obscure deep structures

›Limited for obturator or internal hernias

›Cannot reliably distinguish strangulation from incarceration

›CT required when clinical concern for strangulation persists

›Do not delay surgery for ultrasound if strangulation clinically evident

07Disposition/dispo35

Surgical admission — all confirmed or suspected strangulation

›Emergency operative management

›OR preparation within 2-4 hours of presentation

›Strangulated hernia is a true surgical emergency

›Each hour of delay increases bowel ischemia and necrosis risk

›Preoperative optimization

›Fluid resuscitation target MAP >= 65 mmHg

›Electrolyte correction before induction

›Broad-spectrum antibiotics administered preoperatively

›Anesthesia classification and consent

›High ASA class patients require explicit risk discussion

›Written consent obtained when patient capacity allows

ICU vs ward postoperative disposition

›ICU indications after strangulated hernia repair

›Bowel resection performed

›Anastomotic leak monitoring

›Nutritional support planning

›Septic shock on presentation

›Vasopressor requirement postoperative

›Ongoing lactate normalization monitoring

›Significant comorbidities

›Cardiac or respiratory compromise requiring monitoring

›Renal failure requiring dialysis consideration

›Ward admission criteria

›Hernia repair without resection, hemodynamically stable

›Return of bowel function monitoring

›Diet advancement postoperatively

›Uncomplicated course anticipated

08Treatment/t78

Immediate resuscitation

›IV fluid resuscitation

›Balanced crystalloid — lactated Ringer's or normal saline

›Initial bolus 20-30 mL/kg IV for hypotension or sepsis

›Reassess after each bolus — avoid fluid overload

›Target endpoints

›MAP >= 65 mmHg

›Urine output >= 0.5 mL/kg/hour

›Lactate trending down on serial measurements

›Vasopressors for refractory hypotension

›Norepinephrine first-line vasopressor

›Starting dose 0.01-0.1 mcg/kg/minute IV infusion

›Titrate to MAP >= 65 mmHg

›Maximum dose 3 mcg/kg/minute before adding second agent

›Vasopressin as second agent

›0.03-0.04 units/minute IV fixed dose

›Adjunct to norepinephrine, not first-line

Analgesia and antiemetics

›Opioid analgesia

›Morphine IV

›0.05-0.1 mg/kg IV, repeat every 5-10 minutes titrated to pain relief

›Monitor respiratory status

›Fentanyl IV

›1-2 mcg/kg IV initial dose

›Preferred in renal failure — no active metabolite accumulation

›Antiemetics

›Ondansetron IV

›4 mg IV every 6 hours as needed

›Avoid in prolonged QT — ECG review before administration

›Metoclopramide IV

›10 mg IV every 8 hours

›Avoid in complete bowel obstruction — risk of worsening

Antibiotics

›Antibiotic indications

›Strangulation suspected or confirmed

›Broad-spectrum coverage before surgery

›Administer within 60 minutes of incision — Class I recommendation

›Bowel perforation or peritonitis

›Extended coverage with anaerobic and gram-negative spectrum

›Duration guided by operative findings

›Preferred regimens

›Piperacillin-tazobactam IV

›3.375 g IV every 6 hours or 4.5 g IV every 8 hours

›Renal dosing if GFR < 40 mL/min

›Cefazolin IV plus metronidazole — for uncomplicated operative prophylaxis

›Cefazolin 2 g IV within 60 minutes of incision

›Metronidazole 500 mg IV if anaerobic coverage needed

›Meropenem IV — for severe sepsis or healthcare-associated pathogens

›1 g IV every 8 hours

›Renal adjustment based on creatinine clearance

Surgical management

›Principles of operative management

›Hernia sac contents viability assessment

›Warm saline packing and reassessment of questionable bowel

›Bowel resection with primary anastomosis if nonviable

›Mesh use decision in contaminated field

›Avoid synthetic mesh in contaminated or frankly infected fields

›Biologic mesh may be considered in selected cases

›Primary tissue repair preferred when gross contamination present

›Laparoscopic vs open approach

›Laparoscopic feasible in selected cases without contamination

›Open approach for peritonitis, hemodynamic instability, or complex anatomy

Manual reduction (taxis) — selected cases only

›Taxis criteria — only when strangulation signs absent

›Appropriate candidates

›Duration < 24 hours from onset

›No fever, no peritoneal signs, no skin changes

›No lactate elevation

›Technique

›IV morphine 0.05-0.1 mg/kg plus short-acting benzodiazepine — midazolam 0.02-0.05 mg/kg IV

›Trendelenburg positioning

›Gentle sustained pressure toward hernia defect

›Absolute contraindications

›Any suspicion of strangulation

›Risk of reducing necrotic bowel into abdomen

›Skin changes, fever, peritoneal signs, or elevated lactate

Nasogastric decompression

›NGT placement indications

›Bowel obstruction with distension or vomiting

›Low intermittent suction

›Monitor output volume and quality

›Feculent or bilious nasogastric output

›Indicates high-grade obstruction

›Aspiration risk reduction

09Special Populations/sp79

Pregnancy

›Physiologic considerations in pregnancy

›Displaced anatomy alters hernia presentation

›Enlarged uterus displaces bowel — atypical pain location

›Umbilical and incisional hernias more common in pregnancy

›Increased intra-abdominal pressure promotes incarceration

›Third trimester highest risk

›Femoral hernias less common than inguinal in pregnancy

›Diagnostic imaging in pregnancy

›Ultrasound first-line to avoid fetal radiation

›Color Doppler assesses bowel viability

›Less sensitive than CT for full abdominal assessment

›MRI acceptable — no ionizing radiation

›Gadolinium contrast avoided in first trimester

›Preferred over CT when diagnosis uncertain

›CT with IV contrast — if MRI unavailable and strangulation suspected

›Radiation risk to fetus < 50 mGy considered acceptable in emergency

›Benefits of diagnosis outweigh radiation risk in suspected strangulation

›Surgical considerations in pregnancy

›Strangulated hernia is absolute surgical indication regardless of gestation

›Maternal survival is the primary priority

›Fetal monitoring intraoperatively when viable gestation

›Anesthesia approach

›General anesthesia preferred for complex cases

›Left lateral displacement of uterus to prevent aortocaval compression

›Antibiotic selection

›Beta-lactams safe — cefazolin for surgical prophylaxis

›Metronidazole acceptable in second and third trimesters

›Avoid aminoglycosides unless no alternative

Geriatric

›Atypical presentation in older adults

›Reduced pain perception — may present with less dramatic pain

›Delirium may be the primary presenting symptom

›Normal temperature despite active strangulation

›Delayed presentation — more common due to decreased mobility and social isolation

›Higher likelihood of bowel necrosis at presentation

›Mortality significantly higher when presentation is delayed

›Elevated operative risk

›Multiple comorbidities — cardiac, pulmonary, renal

›Careful preoperative optimization within time constraints

›Anesthesia and surgery risk discussion with patient and family

›Frailty scoring

›Clinical Frailty Scale guides goals-of-care discussions

›Extreme frailty — palliative care involvement may be appropriate

›Perioperative considerations

›Renal dosing of all medications

›Antibiotics dosed by GFR

›Opioids with caution — delirium risk

›Delirium prevention bundle

›Early mobilization, orientation cues, sleep hygiene

›Minimize sedating medications

›Nutritional support

›Early enteral nutrition after bowel function returns

›Malnutrition assessment — albumin, prealbumin

Pediatrics

›Epidemiology of pediatric hernias

›Inguinal hernia most common requiring surgery in children

›Premature infants have highest incidence — up to 30%

›Male predominance with right-sided predominance

›Incarceration rate 10-20% in first year of life

›Strangulation risk highest in first 6 months of life

›Elective repair typically performed promptly after diagnosis to prevent incarceration

›Clinical assessment in children

›Inconsolable crying and irritability as pain surrogates

›Abdominal examination in relaxed or sleeping child

›Feeding intolerance and vomiting as obstruction markers

›Reduction attempt in infants

›Manual reduction attempted if no strangulation signs and duration < 12 hours

›Trendelenburg position and ice pack to reduce edema

›IV analgesia before attempt

›Pediatric-specific treatment

›Fluid resuscitation — weight-based

›Normal saline 10-20 mL/kg IV bolus, reassess after each

›Target urine output 1 mL/kg/hour

›Antibiotic dosing — weight-based

›Ampicillin-sulbactam 50 mg/kg IV (ampicillin component) every 6 hours

›Cefazolin 25-50 mg/kg IV every 8 hours for surgical prophylaxis

›Metronidazole 7.5 mg/kg IV every 6 hours if anaerobic coverage needed

›Surgical approach

›Inguinal approach for inguinal hernias

›Contralateral exploration considered in young infants — high metachronous hernia rate

›Laparoscopic approach feasible in experienced centers

10Background/b62

Epidemiology

›Incidence and burden

›Inguinal hernias affect approximately 25% of men and 2% of women over their lifetime

›Approximately 700,000 inguinal hernia repairs performed annually in the United States

›Femoral hernias account for 2-4% of all groin hernias

›Strangulation rates by hernia type

›Femoral hernia — 22% strangulation risk at 1 month, 45% at 21 months

›Inguinal hernia — approximately 3-5% lifetime risk of strangulation

›Umbilical hernia — intermediate strangulation risk

›Mortality

›Elective hernia repair mortality < 0.5%

›Emergency repair for strangulation — mortality 5-10% overall

›Mortality rises to 20-30% when bowel resection required

›Delayed presentation > 24 hours dramatically increases mortality

Pathophysiology

›Mechanism of strangulation

›Incarceration — irreducible hernia contents without vascular compromise

›Bowel, omentum, or other abdominal contents trapped in hernia defect

›Tight fascial ring prevents reduction

›Progression to strangulation

›Venous outflow obstruction occurs first

›Venous congestion leads to edema and increasing pressure

›Arterial inflow eventually compromised — ischemia ensues

›Bowel ischemia cascade

›Mucosal barrier failure — bacterial translocation

›Transmural necrosis — perforation risk

›Systemic inflammatory response and sepsis

›Anatomy of common hernias

11Patient Discharge Instructions/pdi44

copy discharge instructions

›Strangulated hernia — post-surgical discharge information

›Wound care

›Keep surgical wound clean and dry for 48 hours

›Gauze dressing change daily or when soiled

›Absorbable sutures dissolve on their own

›Activity restrictions

›No lifting greater than 5 kg for 4-6 weeks

›Walking encouraged from day 1

›No strenuous activity or sports for 6 weeks

›Driving only when you can perform an emergency stop without pain — usually 1-2 weeks

›Diet after bowel surgery

›Start with clear fluids then advance to regular diet as tolerated

›High-fiber foods to avoid constipation

›Adequate hydration — at least 6-8 glasses of water daily

›Avoid alcohol while taking prescription pain medications

›Warning signs — return to emergency department immediately

›Wound warning signs

›Increasing redness, swelling, or warmth around surgical wound

›Wound opening or discharge of pus

›Foul-smelling discharge from wound

›Systemic warning signs

›Fever above 38.5 C

›Severe abdominal pain or cramping

›Vomiting that will not stop

›No bowel movement for more than 3 days

›Inability to pass gas

›Urgent hernia-related warning signs

12References/r27

Guidelines and key sources

›Surgical society guidelines

›European Hernia Society guidelines on groin hernia management

›Recommendation for urgent operative management of strangulated hernias

›Mesh use recommendations in contaminated fields

›World Society of Emergency Surgery guidelines for acute hernia management

›Timing of surgery and resuscitation recommendations

›Antibiotic prophylaxis protocols

›ACEP clinical policy guidance on acute abdominal pain evaluation

›Imaging recommendations for suspected bowel obstruction

›Key evidence sources

›Cochrane systematic review — timing of inguinal hernia repair

›Evidence for femoral hernia strangulation risk at 1 and 21 months

›Class I recommendation for urgent repair of femoral hernias at diagnosis

›Lactate and WBC as predictors of bowel resection in strangulated hernia

›Lactate >= 2.0 mmol/L strongest independent predictor — prospective studies

›WBC > 18.5 x 10^9/L and NLR > 6.5 — combined predictive value

›CT imaging performance for strangulation assessment

›Reduced bowel wall enhancement — 56% sensitivity, 94% specificity for strangulation

›Absence of mesenteric fluid — negative LR 0.16 for ruling out strangulation

›AUC 0.91 for combined CT feature set predicting strangulation

›ICD-10 coding reference

›K40.0 — bilateral inguinal hernia with obstruction, without gangrene

›K40.1 — bilateral inguinal hernia with gangrene

›K41.0 — bilateral femoral hernia with obstruction, without gangrene

›K41.1 — bilateral femoral hernia with gangrene

›K46.0 — unspecified abdominal hernia with gangrene

›K46.1 — unspecified abdominal hernia with obstruction, without gangrene

Evidence & Review

Evidence & Review