Acute Appendicitis, Intussusception, Pyloric Stenosis, Testicular Torsion, and Incarcerated Hernia

Pediatric Surgical Emergencies: Acute Abdomen and Scrotal Conditions

Paediatric surgical emergencies present with rapidly evolving pathophysiology where swift clinical decision-making dictates organ preservation and survival. Paediatricians must master the diagnostic and resuscitation imperatives of the acute surgical abdomen, neonatal intestinal obstruction, and acute scrotal crises, adhering strictly to timing-critical clinical rules.

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Infantile Hypertrophic Pyloric Stenosis (IHPS)

Infantile Hypertrophic Pyloric Stenosis (IHPS) is the most frequent surgical cause of non-bilious vomiting in early infancy, occurring in 2 to 4 per 1,000 live births.

Pathophysiology and Demographics

• Pathogenesis: Marked hypertrophy and hyperplasia of the circular smooth muscle layer of the pyloric sphincter, leading to severe narrowing, elongation, and mechanical obstruction of the pyloric canal.
• Demographics: Predominantly affects infants aged 3 to 6 weeks (peak presentation at 3–4 weeks; exceptional before 2 weeks or after 12 weeks of age). Significant male preponderance (male-to-female ratio of 4:1 to 5:1), with a marked predilection for firstborn males and a positive family history.
• Macrolide Exposure Link: Direct infant exposure to erythromycin or azithromycin, especially during the first 2 weeks, increases IHPS risk. Maternal exposure in late pregnancy or early lactation has a weaker, less certain association; the infant risk multiplier must not be applied to maternal treatment.

Clinical Presentation and Physical Examination

• Progressive Projectile Non-Bilious Vomiting: Emesis begins as mild regurgitation but rapidly progresses over days to forceful, projectile, non-bilious vomiting occurring during or immediately following every feed. Because the mechanical stenosis is proximal to the ampulla of Vater, the vomitus contains curdled milk or gastric juices and is NEVER bile-stained.
• The 'Hungry Vomiter': In stark contrast to infants with gastroenteritis or sepsis who are lethargic and anorexic, an infant with pyloric stenosis remains famished, active, and eager to re-feed immediately after vomiting.
• Physical Examination Findings:
  • The Palpable 'Pyloric Olive': A firm, hard, mobile, non-tender, olive-shaped mass (1 to 2 cm in diameter) palpable in the right upper quadrant or epigastrium just lateral to the right rectus muscle. Palpation is easiest when the stomach is empty immediately after vomiting or while soothing the infant with sugar water on a pacifier.
  • Visible Gastric Peristaltic Waves: Distinct peristaltic waves travelling across the upper abdomen from the left costal margin toward the right epigastrium.
  • Dehydration and Faltering Weight: Sunken anterior fontanelle, loss of subcutaneous fat, dry mucous membranes, prolonged capillary refill, and severe weight loss.

Persistent Projectile Emesis (Loss of Gastric HCl: H+, Cl-, H2O)
                              |
         +--------------------+--------------------+
         |                                         |
   Loss of H+ & Cl-                        Volume Depletion
         |                                         |
Metabolic Alkalosis (Elevated HCO3-)      RAAS Activation (Aldosterone Release)
         |                                         |
Hypochloremia (<100 mmol/L)               Renal Na+ Reabsorption in Cortical Tubule
                                                   |
                              +--------------------+--------------------+
                              |                                         |
                      Excretion of K+ (Hypokalemia)           Excretion of H+ (Paradoxical Aciduria)
                              |                                         |
               HYPOCHLOREMIC, HYPOKALEMIC METABOLIC ALKALOSIS WITH PARADOXICAL ACIDURIA

The Classic Pathophysiological Metabolic Derangement

Persistent vomiting causes progressive loss of gastric hydrochloric acid (H+ and Cl-), water, and minor amounts of potassium, resulting in Hypochloremic, Hypokalemic Metabolic Alkalosis with Paradoxical Aciduria:

1. Hypochloremic Alkalosis: Gastric juice contains high concentrations of HCl (approximately 100–120 mmol/L of Cl- and 80–100 mmol/L of H+). Vomiting creates a severe chloride deficit and an equimolar rise in plasma bicarbonate (HCO3-).
2. Hypokalemia: Gastric potassium loss is modest, but severe intravascular hypovolemia activates the renin-angiotensin-aldosterone system (RAAS). In the renal collecting duct, aldosterone promotes maximal sodium conservation at the expense of obligate urinary potassium (K+) excretion.
3. Paradoxical Aciduria: Volume depletion and secondary aldosteronism promote sodium conservation with renal hydrogen secretion. Potassium depletion further promotes hydrogen loss as renal H+/K+ exchange retains potassium. Consequently, the kidneys excrete an acidic urine despite severe, life-threatening systemic alkalosis.

Diagnostic Ultrasonography Criteria

Abdominal ultrasonography is the non-invasive gold standard (sensitivity and specificity >98%):

• Pyloric Muscle Thickness: ≥3.0 mm (transverse double-muscle thickness ≥6 mm; <2 mm is normal).
• Pyloric Channel Length: ≥14 to 15 mm.
• Real-time demonstration of complete failure of gastric contents to pass through the elongated, narrow channel into the duodenal bulb.

Resuscitation and Surgical Dictum

• Resuscitation Protocol:
  1. Stop all oral feeds; pass an open-bore nasogastric tube (size 8 or 10 Fr) on free drainage to decompress the stomach and prevent pulmonary aspiration.
  2. If the infant is clinically in shock, deliver a crystalloid bolus (10–20 mL/kg of 0.9% normal saline).
  3. Administer intravenous maintenance plus replacement fluid: 0.9% Normal Saline with 5% or 10% Dextrose at 1.5 times maintenance (150 mL/kg/day). Normal saline provides 154 mmol/L of chloride, replenishing the chloride debt and allowing the kidneys to excrete bicarbonate.
  4. Add potassium chloride (20–40 mmol/L) to the infusion bag ONLY after active urine output (>1–2 mL/kg/hr) has been verified.
• Definitive Pre-Operative Biochemical Targets:
  • Serum Chloride >100 mmol/L (target >102–104 mmol/L).
  • Serum Bicarbonate (HCO3-) <30 mmol/L (target <26–28 mmol/L).
  • Serum Potassium >3.5–4.0 mmol/L.
  • Normal hydration status with brisk capillary refill and normal urine output.
• Definitive Operation: Ramstedt Pyloromyotomy (open transverse incision or laparoscopic): Longitudinal incising and blunt separation of the hypertrophic circular pyloric muscle fibers down to the submucosa, allowing the mucosal layer to herniate outward cleanly. Feeds are cautiously reintroduced within 4 to 6 hours postoperatively.

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Intussusception

Intussusception is the invagination (telescoping) of a proximal segment of intestine (intussusceptum) into the lumen of the adjacent distal bowel segment (intussuscipiens). It represents the leading cause of intestinal obstruction in infants aged 6 to 36 months.

Pathophysiological Anatomy and Lead Points

• Most Common Form: Ileocolic intussusception (accounting for ~90% of cases), wherein the terminal ileum invaginates through the ileocecal valve into the colon, occasionally propagating as far as the rectum.
• Age and Etiological Demographics:
  • Infants aged 6 to 36 months (peak 6–9 months): >90% are idiopathic. The lead point consists of hyperplastic lymphoid tissue (Peyer's patches) within the terminal ileum, triggered by recent viral infections (adenovirus, human herpesvirus 6, rotavirus vaccine).
  • Older children, especially >5 years, or atypical/recurrent presentations: Consider a pathological lead point, including Meckel diverticulum (most common), intestinal duplication cyst, polyp (Peutz-Jeghers syndrome), lymphoma, or intramural hematoma in Henoch-Schönlein purpura.
• Vascular Cascade: The invaginated bowel drags its mesentery, compressing low-pressure mesenteric veins and lymphatic channels. Progressive venous engorgement leads to massive bowel wall edema, arterial insufficiency, transmural ischemic infarction, bowel perforation, peritonitis, and septic shock.

                        [Ileocolic Intussusception]
                                     |
     Proximal Terminal Ileum Invaginates into Distal Cecum / Colon
                                     |
                  Compression of Mesenteric Blood Vessels
                                     |
          Venous Congestion -> Mural Edema -> Arterial Compromise
                                     |
           Ischemia & Sloughing of Mucosa + Capillary Bleeding
                                     |
                     ['RED CURRANT JELLY' STOOLS]
                                     |
         Transmural Gangrenous Necrosis -> Perforation -> Peritonitis

Classical Clinical Triad and Signs

1. Paroxysmal Severe Colicky Abdominal Pain: The infant suddenly screams, turns pale, diaphoreses, and vigorously draws their knees up to their chest. Paroxysms last 2 to 3 minutes and recur every 15 to 20 minutes.
2. Vomiting: Initially non-bilious gastric contents, becoming bilious as small-bowel obstruction progresses.
3. 'Red Currant Jelly' Stools: Evacuation of dark, mucoid blood mixed with sloughed intestinal epithelium.

• Apathy and Lethargy (Encephalopathic Presentation): Between paroxysms, the infant often exhibits profound somnolence, lethargy, or coma-like stupor (mediated by endogenous endorphin release during ischemia), frequently misleading clinicians to suspect encephalitis or toxin ingestion.
• Physical Examination:
  • Sausage-Shaped Abdominal Mass: A firm, smooth, tubular, sausage-like mass palpable in the right upper quadrant or epigastrium.
  • Dance's Sign: A palpable emptiness or concavity in the right lower quadrant, caused by displacement of the cecum and ascending colon into the transverse colon.

Diagnostic Ultrasonography

• Imaging Gold Standard: High-frequency abdominal ultrasonography boasts a sensitivity and specificity approaching 98% to 100%.
  • Transverse Plane: 'Target Sign' / 'Doughnut Sign' / 'Bulls-Eye Sign': Concentric alternating hypoechoic and hyperechoic rings representing the outer receiving bowel wall and inner invaginated loops, measuring >3.0 cm in diameter.
  • Longitudinal Plane: 'Pseudokidney Sign' / 'Sandwich Sign': Parallel hypoechoic and hyperechoic layers resembling renal parenchyma.

Management and Enema Reduction Protocol

• First-Line Non-Operative Reduction: Pneumatic (Air) Enema or Hydrostatic (Saline or Water-Soluble Contrast) Enema under fluoroscopic or ultrasonographic guidance in a hemodynamically stable patient. Pneumatic reduction is superior, achieving success rates >85–90% with lower perforation rates and cleaner peritoneal contamination if rupture occurs.
• Absolute Contraindications to Non-Operative Reduction:
  1. Signs of peritonitis (abdominal rigidity, involuntary guarding, rebound tenderness).
  2. Pneumoperitoneum (free subdiaphragmatic air on erect or decubitus plain radiograph indicating perforation).
  3. Uncompensated septic or hypovolemic shock.
• Surgical Exploration: Indicated when non-operative enema reduction fails (after 2–3 attempts), when peritonitis or perforation is present, or when a pathological lead point is identified. Involves open or laparoscopic manual reduction by gently squeezing ('milking') the distal bowel back toward the ileum (never pulling the proximal bowel, which tears ischemic gut); non-viable bowel is resected with primary anastomosis.

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Intestinal Malrotation and Midgut Volvulus

Midgut volvulus is the most time-critical surgical emergency of the neonatal period.

Embryology and Pathophysiology

During the 4th to 10th weeks of fetal life, the midgut normally herniates into the physiological umbilical cord and undergoes a 270-degree counterclockwise rotation around the axis of the superior mesenteric artery (SMA). Upon returning to the abdomen, the duodenojejunal (DJ) flexure is anchored at the ligament of Treitz in the left upper quadrant, while the cecum is fixed in the right lower quadrant, creating a broad, widely anchored mesenteric base extending obliquely from left upper to right lower quadrant.

• Malrotation: Occurs when rotation fails or arrests prematurely (typically at 90 or 180 degrees):
  • The DJ flexure fails to cross the midline, remaining on the right side of the spine.
  • The cecum remains in the epigastrium or right upper quadrant, tethered across the duodenum by anomalous peritoneal fibrous bands (Ladd's bands), causing extrinsic mechanical duodenal obstruction.
  • The Mesenteric Pedicle is Markedly Narrow: Instead of a broad base, the entire midgut (from the 2nd part of the duodenum to the mid-transverse colon) is suspended on a tiny, stalk-like neurovascular pedicle containing the superior mesenteric vessels.
• Midgut Volvulus: The entire midgut twists clockwise around this narrow mesenteric pedicle, immediately strangulating the superior mesenteric vein (venous thrombosis and hemorrhagic infarction) followed by occlusion of the superior mesenteric artery. Total irreversible gangrene of the entire small intestine occurs within hours.

Normal Broad Mesentery                             Malrotation with Narrow Pedicle & Volvulus
----------------------                             ------------------------------------------
[Ligament of Treitz]                                  Duodenum
       \                                                 \  <-- Extrinsic Ladd's Bands
        \   Broad Mesenteric                              \      across duodenum
         \  Attachment (Anchored)                          \   Narrow Pedicle / Stalk
          \                                                 O  <-- CLOCKWISE TWISTING (VOLVULUS)
           \                                               / \      Occludes SMA & SMV!
          [Cecum in RIF]                              [Small Intestine Infarction & Gangrene]

The Golden Clinical Rule

Diagnostic Evaluation and Management

• Clinical Signs: 75% present within the first month of life (predominantly within the first 3 to 7 days). Abdominal distension is often absent early because the obstruction is proximal duodenal. Rapid progression to abdominal wall erythema, hematochezia, peritonitis, metabolic acidosis, and septic shock reflects established bowel necrosis.
• Upper Gastrointestinal (UGI) Contrast Series (Gold Standard):
  • Obtain urgently in a clinically stable infant after resuscitation and surgical assessment. Do not delay emergency surgery for contrast imaging when clinical compromise or abdominal signs warrant immediate operation.
  • Pathognomonic Findings: The DJ flexure lies abnormally to the right of the spine and inferior to the duodenal bulb; contrast reveals a characteristic 'Corkscrew sign' (the twisted, spiraling duodenum and proximal jejunum) or complete duodenal 'beak-like' cutoff.
• Abdominal Ultrasound: Demonstrates inversion of the normal mesenteric vessel orientation (the Superior Mesenteric Vein / SMV lies to the left of the SMA, rather than its normal rightward position) and the 'Whirlpool sign' (clockwise swirling of mesenteric vessels on color Doppler).
• Emergency Surgery: The Ladd Procedure:
  1. Immediate counterclockwise detorsion of the volvulus.
  2. Surgical division of anomalous Ladd's bands across the duodenum.
  3. Broadening of the narrow mesenteric base to prevent future twisting.
  4. Repositioning the gut in a non-rotated state: small intestine placed entirely in the right abdomen, colon placed entirely on the left.
  5. Prophylactic Appendectomy: Essential because the cecum now permanently resides in the left upper quadrant, precluding typical future diagnosis of right lower quadrant appendicitis.

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Acute Appendicitis

Acute appendicitis is the most common cause of an acute surgical abdomen in children and adolescents, carrying a lifetime risk of approximately 7% to 9%.

Pathogenesis and the Vulnerability of Young Children

• Luminal Obstruction: Triggered by a fecalith (appendicolith) in 30% of cases, or by lymphoid follicular hyperplasia (following viral upper respiratory infection or gastroenteritis), pinworms (Enterobius vermicularis), or carcinoid tumors. Trapped secretions produce intraluminal distension, bacterial proliferation, venous congestion, transmural ischemia, gangrene, and perforation.
• High Perforation Rate in Toddlers and Young Children (<5 years): Perforation rates exceed 50% to 70% in children younger than 5 years, compared to 15% to 20% in adolescents. This vulnerability stems from atypical, non-specific early symptoms, communication barriers, delayed diagnosis, and an underdeveloped, thin, short greater omentum that cannot effectively wall off an inflamed appendix, leading to generalized peritonitis.

Clinical Presentation and Progression

• Pain Sequence: Dull, aching, visceral, periumbilical pain (referred via T10 visceral afferents) lasting 12 to 24 hours, followed by migration to the right iliac fossa (McBurney's point) as transmural inflammation contacts the somatic parietal peritoneum, becoming sharp, intense, constant, and exacerbated by coughing, walking, or vehicle bumps.
• Pain Precedes Vomiting: Low-grade pyrexia (37.8–38.5°C), anorexia (anorexia is a sensitive sign; a child eager to eat their favorite meal makes appendicitis unlikely), nausea, and vomiting. In appendicitis, abdominal pain characteristically precedes vomiting; if vomiting precedes abdominal pain, gastroenteritis or food poisoning is more probable.
• Classical Physical Examination Signs:
  • Localized tenderness and involuntary muscle guarding at McBurney's point (one-third the distance along a line from the anterior superior iliac spine to the umbilicus).
  • Rovsing's Sign: Deep palpation in the left lower quadrant produces referred pain in the right lower quadrant.
  • Psoas Sign: Pain elicited on passive extension of the right hip with the patient in the left lateral decubitus position; indicates a retrocecal appendix irritating the psoas muscle.
  • Obturator Sign: Pain on passive internal rotation of the flexed right hip; indicates a pelvic appendix irritating the obturator internus muscle.

Imaging and Management Protocol

• Graded-Compression Abdominal Ultrasonography: Primary first-line imaging modality in children to eliminate ionizing radiation exposure. Diagnostic criteria for appendicitis:
  • Non-compressible, blind-ending tubular structure in the right lower quadrant.
  • Outer appendiceal diameter >6.0 mm.
  • Target appearance on cross-section with thickened, hyperemic mural blood flow on color Doppler ('ring of fire').
  • Presence of a hyperechoic appendicolith with acoustic shadowing, periappendiceal fat hyperechogenicity, or localized fluid collections.
• Computed Tomography (CT) or MRI: Reserved for equivocal ultrasound scans in obese children or complex diagnostic dilemmas.
• Management:
  • NPO, intravenous crystalloid rehydration, and adequate intravenous analgesia (paracetamol, opioids; analgesia does NOT mask physical signs or impede diagnostic accuracy).
  • Preoperative broad-spectrum intravenous antibiotics covering enteric Gram-negative bacilli and anaerobes (e.g., Cefuroxime / Ceftriaxone plus Metronidazole, or Piperacillin-Tazobactam).
  • Definitive Treatment: Early Laparoscopic Appendectomy.
  • Walled-Off Perforated Appendiceal Abscess / Phlegmon: Selected stable children without generalized peritonitis may receive IV antibiotics with drainage of a suitable abscess; early laparoscopy is another option where expertise permits. After successful nonoperative treatment, interval appendectomy is selective, not routine. Persistent/recurrent symptoms or failed conservative treatment require surgical reassessment.

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Acute Testicular Torsion

Acute testicular torsion represents an acute, time-critical surgical emergency. Testicular viability is governed by the speed of detorsion.

Anatomy: The Bell-Clapper Deformity

• Intravaginal Torsion: Accounts for >90% of pediatric cases, with peak incidence occurring during the pubertal growth surge (ages 12 to 18 years).
• The 'Bell-Clapper Deformity': The underlying developmental anomaly. Normally, the tunica vaginalis adheres firmly to the posterior and lateral surfaces of the testis and epididymis, preventing rotation. In patients with the bell-clapper anomaly, the tunica vaginalis attaches abnormally high up on the spermatic cord, enveloping the entire testis, epididymis, and distal cord. The testis is suspended freely within the tunica vaginalis like a clapper inside a bell, predisposing it to spontaneous longitudinal rotation.
• Bilateral Risk: The bell-clapper deformity is a congenital, bilateral anatomical anomaly in 50% to 80% of affected males, rendering the contralateral testis at lifelong risk of subsequent torsion.
• Extravaginal Torsion: Occurs almost exclusively in neonates in utero or during delivery, where the entire spermatic cord and tunica vaginalis twist outside the external spermatic fascia; typically presents as a firm, painless, bluish scrotal mass at birth.

Normal Tunica Attachment                           Bell-Clapper Deformity (Torsion Risk)
------------------------                           -------------------------------------
   Spermatic Cord                                     Spermatic Cord
         |                                                  |
         |                                             Tunica Vaginalis attaches HIGH
   Posterior Tunica                                         |
   Attachment anchors                                  +----+----+
   Testis firmly                                       |  TESTIS | <-- Testis hangs freely like
   to Scrotal Wall                                     |    &    |     a clapper in a bell;
                                                       |  EPID.  |     rotates freely!
                                                       +----+----+

Clinical Presentation and Hallmark Examination Findings

• Presentation: Sudden, excruciating, unilateral scrotal pain, often awakening the patient from sleep in the early morning (due to dartos muscle and cremasteric contraction during REM sleep) or following vigorous exercise or minor trauma. The pain commonly radiates to the ipsilateral inguinal canal, lower abdomen, or flank, accompanied by severe nausea and vomiting.
• Physical Examination:
  • The affected hemiscrotum is acutely swollen, tender, indurated, and erythematous.
  • High-Riding, Transversely Oriented Testis (Brunzel Sign): The twisting of the spermatic cord shortens its length, drawing the testis high up in the hemiscrotum and forcing it into a horizontal lie.
  • Absent Cremasteric Reflex: Stroking the ipsilateral medial thigh normally induces reflexive contraction of the cremaster muscle, elevating the testis by ≥0.5 cm. The cremasteric reflex is absent in virtually 100% of cases of acute testicular torsion. The presence of a crisp, normal cremasteric reflex strongly argues against torsion.
  • Negative Prehn's Sign: Manual elevation of the scrotum does not alleviate pain (and often intensifies it); in contrast, elevation frequently relieves discomfort in acute epididymo-orchitis.

The 6-Hour Golden Window and Surgical Imperatives

                          [Testicular Salvage Time-Window]

   Time from Pain Onset to Detorsion             Expected Testicular Salvage Rate
  -----------------------------------           ----------------------------------
              < 6 Hours                                      > 90 - 95 %
             6 - 12 Hours                                    ~ 50 %
            12 - 24 Hours                                    < 20 %
              > 24 Hours                                     < 10 % (Hemorrhagic Gangrene)

• Emergency Surgical Exploration & Bilateral Orchidopexy:
  1. Midline or bilateral scrotal incision; opening of the tunica vaginalis.
  2. Immediate detorsion of the spermatic cord (testes usually twist inward toward the midline; manual detorsion involves an outward 'opening a book' rotation, but surgical visualization is definitive).
  3. Assessment of viability: The detorted testis is wrapped in warm, moist saline packs for 10 to 15 minutes while administering 100% oxygen. If arterial perfusion returns and tissue pinks up, the testis is salvaged; if it remains black, non-viable, and gangrenous, orchidectomy is performed for unequivocally necrotic, irreversibly nonviable tissue.
  4. Mandatory Bilateral Orchidopexy: Three-point non-absorbable suture fixation of the salvaged testis AND the contralateral unaffected testis to the dartos pouch, protecting against future contralateral torsion.

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Incarcerated Inguinal Hernia

Indirect inguinal hernias in children result from failure of physiological obliteration of the processus vaginalis (an embryonic diverticulum of parietal peritoneum that descends through the inguinal canal into the scrotum).

Incarceration versus Strangulation

• Epidemiology: Extremely common in premature infants (incidence up to 30%) and young male infants under 1 year of age (right-sided in 60% due to later descent of the right testis).
• Incarceration: An intra-abdominal organ (almost always a loop of small bowel; ovary and fallopian tube in female infants) herniates into the persistent processus vaginalis and becomes mechanically trapped, unable to be reduced back into the abdominal cavity.
• Strangulation: As trapped bowel swells, venous drainage is blocked, followed by arterial compromise, bowel wall gangrene, perforation, and acute testicular infarction (due to compression of the adjacent testicular vessels against the tight internal inguinal ring).

Clinical Presentation and Management Protocol

• Clinical Presentation: Sudden onset of a painful, firm, tender, irreducible swelling in the groin, extending into the scrotum or labium majorum. The infant exhibits extreme irritability, inconsolable crying, and signs of mechanical bowel obstruction (bilious vomiting, abdominal distension, obstipation). Overlying skin erythema, warmth, fever, and leukocytosis indicate impending strangulation or tissue necrosis.
• Manual Reduction (Taxis) for Uncomplicated Incarceration:
  • For an appropriate bowel-containing hernia with no signs of strangulation, gangrene or peritonitis, gentle taxis may be attempted after surgical discussion. Suspected ovary-containing hernias require urgent surgical assessment; do not attempt ED reduction.
  1. Administer adequate intravenous analgesia and light sedation (e.g., morphine or fentanyl) to stop crying and relax the abdominal wall musculature.
  2. Place the infant in the Trendelenburg position (head down, pelvis elevated) and apply a gentle ice pack to the groin for 15 to 20 minutes to reduce tissue edema.
  3. Taxis Technique: The clinician stabilizes the neck of the hernia sac at the internal ring with one hand while applying gentle, steady, circumferential compression to the distal end of the hernia mass with the other hand, guiding the bowel back along the line of the inguinal canal.
  4. Post-reduction Care: Successful reduction is marked by a sudden, palpable 'pop' or gurgle. The infant is admitted for observation, and elective herniotomy is scheduled within 24 to 48 hours prior to discharge (allowing tissue edema to subside while preventing recurrent incarceration).
• Emergency Surgical Exploration:
  • Strictly Contraindicated Taxis: If signs of strangulation (erythema, extreme tenderness, peritonitis, shock) are present, manual taxis is strictly contraindicated because forcing gangrenous, perforated bowel into the peritoneal cavity causes catastrophic peritonitis.
  • Emergent surgical intervention (open inguinal herniotomy with inspection and resection of compromised bowel) is indicated immediately for strangulated hernias or when gentle manual taxis fails.

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Lacerations, Bites and Surgical Wound Care

• Assess the mechanism, time since injury, contamination and possible foreign body (glass may need imaging), and check distal sensation, movement, tendon function and circulation. Consider whether the injury fits the history.
• Clean by thorough irrigation with saline or clean water, then explore and remove debris. Use topical anaesthetic, distraction or procedural sedation when needed.
• Close clean, straight, low-tension wounds with tissue adhesive or adhesive strips. Use sutures for gaping or high-tension wounds; absorbable sutures avoid removal in young children.
• Bites: irrigate thoroughly and generally leave puncture wounds open. Offer prophylactic antibiotics, with co-amoxiclav as first choice, according to the type of bite, whether the skin is broken and blood drawn, the site and the child's risk factors.
• Tetanus: check immunisation status. Depending on the wound and the child's immunisation history, give a tetanus-containing vaccine and/or human tetanus immunoglobulin for tetanus-prone wounds.
• Surgical wounds: keep the dressing on for about 48 hours, after which simple washing is usually acceptable. Increasing pain, redness, swelling, discharge, fever or wound breakdown suggests surgical site infection and needs review, wound culture and treatment or drainage.

Sources: NICE NG184 human and animal bites; UKHSA Green Book chapter 30: tetanus; NICE NG125 surgical site infections.

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Undescended (Maldescended) Testis

• Definitions: an undescended testis cannot be brought into a stable scrotal position. It may be palpable (inguinal or ectopic) or non-palpable (intra-abdominal or absent). A retractile testis can be brought into the scrotum and stays there; it needs no treatment but should be followed until puberty because up to one third ascend.
• Natural history: spontaneous descent occurs mainly in the first months, and about 1% of term boys still have an undescended testis at 1 year. Treatment should start from 6 months because later descent is rare.
• Management (EAU): refer for orchidopexy before 12 months of age, and by 18 months at the latest. Ultrasound or other imaging does not reliably locate the testis and should not delay referral. Non-palpable testes are assessed by examination under anaesthesia and laparoscopy. Hormonal treatment is not offered for unilateral descent.
• Bilateral non-palpable testes, or an undescended testis with hypospadias or atypical genitalia, need urgent endocrine and genetic evaluation for a difference of sex development; a virilised 46,XX infant with congenital adrenal hyperplasia can look like a boy with bilateral undescended testes.
• Risks: reduced fertility, especially when bilateral, and increased testicular cancer risk that rises with later orchidopexy; teach testicular self-examination after puberty.

Source: EAU Guidelines on Paediatric Urology: undescended testes.