Reference

ICU Glossary of Key Terms

Plain-language definitions of terms used throughout the CriticalMindAI platform and the critical-care clinical literature — from clinical tools like the VISAGE score to billing concepts like DRG and MCC.

Intensivist

A physician who specializes in the care of critically ill patients in an intensive care unit (ICU). Intensivists are trained in internal medicine, anesthesiology, surgery, or pediatrics, followed by a fellowship in critical care medicine. In a neuro-ICU, the intensivist manages mechanical ventilation, hemodynamics, sedation, and procedural interventions for patients with acute neurological injury.

Tracheostomy

A surgical airway created by making an incision in the anterior (front) of the neck into the trachea (windpipe). A tracheostomy tube is inserted to provide a stable, long-term airway for patients who require prolonged mechanical ventilation or cannot maintain a safe airway. Tracheostomies allow reduced sedation, improved secretion clearance, and patient communication via speaking valves.

Percutaneous Dilatational Tracheostomy (PDT)

A bedside technique for tracheostomy placement using Seldinger (wire-guided) technique and a series of dilators, typically performed under bronchoscopic guidance. PDT avoids the need for transport to the operating room and is the preferred method in most neuro-ICUs with experienced operators.

PEG (Percutaneous Endoscopic Gastrostomy)

A feeding tube placed into the stomach through the abdominal wall, guided by an endoscope (flexible camera) inserted through the mouth. PEG provides durable enteral nutrition access for patients who cannot swallow safely. It requires endoscopy equipment and an endoscopist.

PUG (Percutaneous Ultrasound-guided Gastrostomy)

A gastrostomy tube placed at the bedside using real-time ultrasound to visualize the stomach, rather than endoscopy. PUG can be performed by a trained intensivist at the ICU bedside, enabling same-session placement with tracheostomy without OR transport.

VISAGE Score

A structured clinical scoring tool developed within the CriticalMindAI pathway to identify neuro-ICU patients who need early tracheostomy and PUG. It scores six factors — Ventilator dependence, ICU stay ≥3 days, Secretion burden, Aspiration risk, GCS ≤8, and Extubation failure — on Day 1 and Day 3 to risk-stratify patients.

GCS (Glasgow Coma Scale)

A neurological scoring system that assesses level of consciousness. It scores three categories: Eye opening (1–4 points), Verbal response (1–5 points), and Motor response (1–6 points). Maximum score is 15 (fully awake and oriented); minimum is 3 (deeply comatose). A GCS of 8 or below is a key threshold indicating severe neurological impairment and high risk of airway compromise.

DRG (Diagnosis-Related Group)

A patient classification system used by Medicare and most payers to determine inpatient hospital reimbursement. Each discharge is assigned one DRG based on diagnoses and procedures. DRGs range by complexity — base DRG, with CC (complication or comorbidity), and with MCC (major complication or comorbidity). Higher-complexity DRGs receive higher reimbursement.

MCC (Major Complication or Comorbidity)

A secondary diagnosis that, when present and documented, significantly increases the complexity of a hospital case and moves it into a higher-weighted DRG (increasing reimbursement). In the neuro-ICU, common MCC conditions include acute respiratory failure, severe sepsis, acute kidney injury, and malnutrition. Accurate MCC documentation is a clinical and compliance responsibility.

CC (Complication or Comorbidity)

A secondary diagnosis that increases DRG weight, but to a lesser degree than an MCC. CCs still represent meaningful clinical complexity. The difference between a CC-level and MCC-level secondary diagnosis determines whether a case falls into DRG 004 vs DRG 003, a difference that can represent significant reimbursement.

Decannulation

The process of removing a tracheostomy tube once a patient no longer requires it. Decannulation is preceded by a structured weaning process including cuff deflation trials, speaking-valve use, tube downsizing, and capping trials. Premature or unstructured decannulation can cause airway emergencies.

Speaking Valve (Passy Muir Valve / PMV)

A one-way valve attached to the tracheostomy tube hub that opens during inhalation and closes during exhalation, redirecting exhaled air through the vocal cords and upper airway. Speaking valves restore voice, improve swallowing function by restoring subglottic pressure, improve olfaction, and support patient communication and neurological engagement.

VAP (Ventilator-Associated Pneumonia)

Pneumonia that develops in patients who have been on mechanical ventilation for ≥48–72 hours. VAP is a major cause of ICU morbidity, prolonged ventilation, and mortality. Early tracheostomy reduces VAP risk through improved secretion management, reduced need for reintubation, and lower aspiration risk compared to prolonged endotracheal intubation.

FEES (Flexible Endoscopic Evaluation of Swallowing)

A bedside procedure in which a flexible endoscope is passed through the nose to visualize the pharynx and larynx during swallowing. FEES directly visualizes aspiration, residue, and pharyngeal clearance. It is used in the neuro-ICU to confirm aspiration risk (a VISAGE factor) and assess readiness for oral intake or decannulation.

Neuro-ICU / NeuroICU

An intensive care unit specialized for patients with acute neurological and neurosurgical conditions, including stroke (ischemic and hemorrhagic), traumatic brain injury (TBI), subarachnoid hemorrhage (SAH), status epilepticus, and post-operative neurosurgical care. Neuro-ICUs use specialized monitoring (ICP monitoring, continuous EEG) and are staffed by neurointensivists.

AI for ICU Billing (AI-Assisted CDI)

Artificial intelligence tools that cross-reference a patient's live clinical data — lab values, vital signs, nursing assessments, physician notes — against the ICD-10 diagnosis list on the current hospital encounter. When the clinical evidence supports a Major Complication or Comorbidity (MCC) or CC condition that has not been explicitly documented, the AI surfaces a real-time query to the responsible physician. This closes the gap between care delivered and care coded without relying solely on retrospective chart review. AI does not assign codes autonomously; the physician must confirm the diagnosis.

AI for Rehab Placement

Artificial intelligence tools that analyze a patient's clinical trajectory, functional status, insurance coverage, and payer-specific prior-authorization criteria to recommend the appropriate post-acute level of care — inpatient rehabilitation facility (IRF), skilled nursing facility (SNF), or long-term acute care hospital (LTACH) — and estimate payer approval probability. AI-assisted placement enables case managers to initiate authorization workflows before the patient is clinically ready to transfer, reducing preventable discharge delays.

IRF (Inpatient Rehabilitation Facility)

A specialized post-acute setting providing intensive, physician-led rehabilitation — at least 3 hours of therapy per day — for patients who have the functional potential to improve and can tolerate intensive therapy. After neuro-ICU admission, patients with recovering stroke or traumatic brain injury may be appropriate for IRF. Medicare requires compliance with the "60% rule" (at least 60% of IRF patients must have one of 13 qualifying diagnostic conditions).

LTACH (Long-Term Acute Care Hospital)

A hospital-level post-acute facility designed for patients who require continued acute-care services — including mechanical ventilation weaning — for an extended period. Medicare defines LTACH admissions by an average length of stay of at least 25 days. After neuro-ICU admission, LTACH is often appropriate for tracheostomy-dependent patients who are not yet ventilator-liberated and cannot tolerate IRF-level therapy intensity.