False passage / esophageal/paratracheal misplacement. Remove tube immediately. Re-identify CTM by direct finger palpation — landmark failure is the most common cause. Enlarge incision, confirm trachea by digital entry, reinsert under direct visualization. Return to BVM via oral airway if SpO2 allows reoxygenation.

Airway takes priority over hemorrhage. Continue with cric. After tube secured, address bleeding with direct pressure, suture ligation, or packing. Major vessels at risk are the superior cricothyroid arteries (run across the upper third of CTM — reason to incise in the lower third). Involve ENT urgently if hemorrhage is severe.

No absolute contraindications in a true CICO scenario. Relative contraindications where alternate approaches are preferred first: age <8–10 (needle cric or tracheostomy preferred), suspected laryngeal fracture, known laryngotracheal pathology. Risk-benefit still favors cric if no other option exists.

Landmark failure approach: use bimanual "laryngeal handshake" — bilateral palpation from thyroid notch downward in midline. In extreme cases: ultrasound to identify CTM pre-incision if time allows, or aggressive midline incision with blunt dissection to find trachea. Do not repeat the same failed technique more than twice — change your strategy each attempt.

Bacterial meningitis until proven otherwise. Xanthochromia + elevated OP + cloudy CSF = septic meningitis with high ICP. Do not wait for culture results — antibiotics within 30–60 min of presentation. Send all 4 tubes and blood cultures; start empiric vancomycin + ceftriaxone ± ampicillin ± dexamethasone immediately.

Traumatic tap — RBC count decreases from tube 1 to 4 as the needle stops traumatizing the vessel. In true SAH, blood is uniformly distributed with no clearing. If uncertainty: xanthochromia on spectrophotometry of tube 4 centrifuged at >12h from symptom onset is the gold standard.

Post-dural puncture headache (PDPH) — CSF leak causes intracranial hypotension. Conservative: rest, hydration, caffeine 300 mg. Definitive: epidural blood patch 15–20 mL autologous blood — 70–98% success. Prevention: smaller gauge needle (22g), atraumatic pencil-point tip, replace stylet before removal.

Change patient position (seated vs. lateral). If still failing: fluoroscopy or ultrasound-guided LP via Radiology. In obese patients, ultrasound pre-procedurally marks midline and interspace. Never attempt more than 3–4 passes without reassessing strategy and involving an experienced operator.

Right mainstem intubation. Pull tube back 1–2 cm while auscultating until left-sided sounds return. Toddler trachea is ~5 cm — small advancement causes right mainstem. Reconfirm depth at 12 cm; secure firmly.

Vagal-mediated bradycardia from laryngoscopy — dominant cause of cardiovascular instability in pediatric intubation. Remove laryngoscope; provide 100% O₂ via BVM — HR usually recovers. If persistent: atropine 0.02 mg/kg IV. This is why atropine premedication is given routinely before RSI in toddlers.

Failed intubation protocol: 1) Call for help. 2) Return to BVM — oxygenation is priority. 3) Reoxygenate to ≥95%. 4) Reassess: position, blade (try Mac or video laryngoscopy), BURP. 5) If reattempt fails: LMA as rescue airway. 6) Cannot ventilate/oxygenate → needle cric for toddler. Never >3 attempts without escalating.

Sux causes transient hyperkalemia (~0.5–1 mEq/L). Dangerous in: suspected myopathy, crush injury >72h, denervation injury, burns >48h, renal failure with hyperkalemia, MH susceptibility. Also caution in undiagnosed myopathy in children (Duchenne's). Use rocuronium 1.2 mg/kg as RSI-dose alternative; reverse with sugammadex 16 mg/kg if needed.

Traumatic tap: Blood often clears as fluid continues to drain; fluid may streak rather than be uniformly bloody; RBC count typically <10,000/mm³. Hemorrhagic ascites: uniformly bloody throughout; common in hepatocellular carcinoma, trauma, TB, or ruptured tumor. Key action: send fluid for RBC count and hematocrit. If hematocrit of fluid >50% of peripheral blood hematocrit → hemoperitoneum, not traumatic tap → urgent surgical or IR consult. Stop the tap; apply pressure; assess hemodynamics.

Post-paracentesis circulatory dysfunction (PPCD). Large-volume paracentesis triggers massive splanchnic vasodilation via the renin-angiotensin system — effective circulating volume falls, activating vasoconstrictive and sodium-retaining responses → AKI, worsening ascites recurrence, hyponatremia, encephalopathy, and increased mortality. Prevention: albumin 6–8 g per liter removed IV after the procedure. This is standard of care for any tap >5L and is a critical item in this checklist.

Spontaneous bacterial peritonitis (SBP) — PMN count ≥250 cells/mm³ is diagnostic, even before culture results. Do not wait for culture. Immediate management: IV cefotaxime 2g q8h (or ceftriaxone 1g q24h) is first-line empiric therapy; albumin 1.5 g/kg IV at diagnosis + 1 g/kg on day 3 reduces renal failure and mortality. SBP prophylaxis after the episode: norfloxacin or trimethoprim-sulfamethoxazole. Note: culture is positive in only ~40% of SBP cases — a negative culture does NOT rule out SBP if PMN ≥250.

Ascitic leak — occurs when the Z-track technique was not used or was inadequate, leaving a direct channel from peritoneum to skin. Management: place a purse-string suture at the puncture site (0-prolene or 2-0 nylon); apply an ostomy bag to collect and measure output if suture fails; consider tight pressure dressing + positioning to decompress peritoneum. For recurrent or severe leaks: loop diuresis (furosemide + spironolactone) to reduce intraperitoneal pressure while awaiting TIPS or repeat tap.

There is no validated INR or platelet cutoff for paracentesis. Unlike thoracentesis or LP, the current evidence does not support routine FFP or platelet transfusion before paracentesis in cirrhotic patients, even with severe coagulopathy (INR >2.5, platelets <50k). Large observational studies show complication rates are not significantly elevated in cirrhosis regardless of INR. The procedure should be deferred if there is clinically evident DIC, active fibrinolysis, or skin infection at the site. Prophylactic transfusion wastes blood products and carries transfusion risks without benefit.

Small asymptomatic pneumothorax after thoracentesis — does not require immediate chest tube. Management: 100% O₂ by NRB to accelerate nitrogen absorption (1 cm pneumothorax resolves ~1–1.5% per day on room air vs much faster on 100% O₂); repeat CXR in 4–6 hours; admit for monitoring if the patient requires it clinically. Chest tube is indicated for: pneumothorax >20–25%, symptomatic, expanding on repeat CXR, or tension physiology. Prevention: always have the patient exhale/Valsalva during needle removal; use ultrasound guidance.

Re-expansion pulmonary edema (RPE) — occurs when chronically collapsed lung rapidly re-expands. The previously atelectatic lung has increased vascular permeability; rapid pressure equalization causes fluid shifts into the parenchyma. Incidence increases significantly with large volumes and long-standing effusions. Management: stop drainage immediately, supplemental oxygen, upright positioning; severe cases may require CPAP or mechanical ventilation. Prevention: limit drainage to 1,000–1,500 mL per session; monitor pleural pressure with a manometer if available (stop at <−20 cmH₂O).

Complicated parapneumonic effusion / empyema. pH <7.2 in the setting of a PMN-predominant exudate with clinical infection indicates that the effusion will NOT resolve with antibiotics alone. Chest tube drainage is required — or image-guided drain if loculated. Empiric antibiotics covering gram-positives, gram-negatives, and anaerobes (piperacillin-tazobactam or cefepime + metronidazole). If loculated: consider tPA + DNase instillation via chest tube. Thoracic surgery consult for decortication if fibropurulent/organizing stage.

Light's criteria overcall exudate in diuretic-treated transudates. Diuretics concentrate pleural fluid protein and LDH relative to serum, causing falsely elevated ratios. The correction: use the serum-pleural albumin gradient — if >1.2 g/dL, the effusion is a transudate despite meeting Light's exudate criteria. Also check serum BNP (elevated CHF), serum-to-pleural protein gradient >3.1 g/dL = transudate. Clinical context (bilateral effusions, peripheral edema, elevated BNP, cardiomegaly) supports the CHF diagnosis; repeat thoracentesis after diuresis would show classic transudate values.

Tension pneumothorax — air entered during the procedure, and with positive pressure ventilation or respiratory effort, a tension physiology developed. Note the contralateral absent breath sounds — the mediastinum has shifted away from the affected side. This is a clinical emergency: do not wait for CXR. Immediate needle decompression: 14g angiocath at 2nd ICS midclavicular line ipsilateral to the procedure site; rush to large-bore chest tube immediately after. Prevention: always remove the needle/catheter while patient exhales and cover site instantly with occlusive dressing.