Critical Care and Management of the Acutely Ill Patient
Critical care assessment
Use a structured approach: airway, breathing, circulation, disability, and exposure. In the ICU, trend mental status, work of breathing, hemodynamics, urine output, lactate, and oxygenation. Mean arterial pressure matters more than a single systolic reading. Central venous pressure is a poor standalone marker of fluid responsiveness; interpret it with the clinical picture, lactate, and dynamic measures.
Mechanical ventilation requires understanding mode, tidal volume, positive end-expiratory pressure, peak and plateau pressures, and auto-PEEP. In ARDS, lung-protective ventilation uses low tidal volumes and adequate PEEP. Permissive hypercapnia may be acceptable. Weaning requires readiness: resolving cause, adequate oxygenation, hemodynamic stability, manageable secretions, and a spontaneous breathing trial.
Mobilization and safety
Early mobility improves outcomes, but screen first: unstable arrhythmia, active ischemia, severe hypoxemia, rising vasopressor needs, and unsafe lines are relative contraindications. Coordinate sedation and delirium management. Prevent ventilator-associated pneumonia, pressure injury, and ICU-acquired weakness. Communicate with families and document goals of care.
Worked example. A patient with fever, hypotension, and lactate of 4 mmol/L has suspected sepsis. Start the sepsis bundle: cultures, broad-spectrum antibiotics, fluids, and vasopressors if needed after fluid resuscitation. Reassess perfusion. Rule of thumb: stabilize before you mobilize, and reassess after every intervention. If the patient is getting worse during therapy, stop and escalate.