1.6 Neurologic Assessment, Respiratory Failure & Triage

1.6 Neurologic Assessment, Respiratory Failure & Triage

Neurological Assessment: Modified Pediatric Glasgow Coma Scale (pGCS)

In pediatric critical care, neurological impairment frequently compromises protective upper airway reflexes (cough, gag, swallowing). The standard adult Glasgow Coma Scale relies on adult verbal responses; therefore, the modified Pediatric Glasgow Coma Scale (pGCS) integrates developmental preverbal markers.

+-------------------------------------------------------------------------------------------------------------+
|                                 MODIFIED PEDIATRIC GLASGOW COMA SCALE (pGCS)                                |
+------------------------------------+------------------------------------+-----------------------------------+
| Eye Opening (1-4 Points)           | Verbal Response: > 2 yr (1-5 Pts)  | Verbal Response: Preverbal Infant |
+------------------------------------+------------------------------------+-----------------------------------+
| 4: Spontaneous                     | 5: Oriented, appropriate words     | 5: Coos, babbles, smiles, tracks  |
| 3: To verbal command / shouting    | 4: Disoriented, confused words     | 4: Irritable cry, consolable      |
| 2: To painful stimulus             | 3: Inappropriate words             | 3: Cries persistently to pain     |
| 1: No eye opening to any stimulus  | 2: Incomprehensible sounds/moans   | 2: Moans, grunts, inconsolable    |
|                                    | 1: No vocal response to pain       | 1: No vocal response to pain      |
+------------------------------------+------------------------------------+-----------------------------------+
| Best Motor Response (1-6 Points)                                                                            |
+-------------------------------------------------------------------------------------------------------------+
| 6: Obeys commands (infant: spontaneous purposeful movement)                                                 |
| 5: Localizes to painful stimulus                                                                            |
| 4: Normal withdrawal / flexion to painful stimulus                                                          |
| 3: Abnormal flexion to pain (decorticate posturing; cerebral cortical dysfunction)                          |
| 2: Abnormal extension to pain (decerebrate posturing; midbrain/brainstem compression)                        |
| 1: Flaccid; completely absent motor response to pain                                                        |
+-------------------------------------------------------------------------------------------------------------+

Airway Decision-Making When GCS Is Low

A total pGCS score of $\le 8$ signals severe neurological depression and an urgent airway assessment, but the number alone does not prove loss of every protective reflex or create an automatic intubation rule. Evaluate airway patency, cough and gag, secretion handling, oxygenation, ventilation, trajectory, reversible causes, and the anticipated course. Assist ventilation immediately when it is inadequate and secure the airway when the child cannot protect it, cannot maintain gas exchange, or is deteriorating despite support.

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Differentiating Respiratory Distress from Respiratory Failure

The fundamental clinical judgment tested on the NBRC-NPS exam is recognizing the transition from compensated respiratory distress to uncompensated respiratory failure.

+-------------------------------------------------------------------------------------------------------------+
|                     RESPIRATORY DISTRESS VERSUS RESPIRATORY FAILURE: CLINICAL SPECTRUM                      |
+-----------------------+---------------------------------------------+---------------------------------------+
| Clinical Feature      | Respiratory Distress (Compensated)          | Respiratory Failure (Decompensated)   |
+-----------------------+---------------------------------------------+---------------------------------------+
| Definition            | Increased work of breathing maintaining     | Inability to maintain adequate        |
|                       | adequate pulmonary gas exchange.            | oxygenation (PaO2) or ventilation.    |
+-----------------------+---------------------------------------------+---------------------------------------+
| Mental Status         | Alert, anxious, irritable, easily consolable| Lethargic, somnolent, stuporous,      |
| (Appearance / TICLS)  | with intact eye contact.                    | coma, uncooperative, glassy gaze.     |
+-----------------------+---------------------------------------------+---------------------------------------+
| Respiratory Rate      | Marked tachypnea (above normal for age).    | Bradypnea, irregular pauses, or       |
| & Effort              | Pronounced retractions, nasal flaring.      | agonal gasping (respiratory fatigue). |
+-----------------------+---------------------------------------------+---------------------------------------+
| Auscultation          | Loud wheezing, stridor, coarse crackles;    | "Silent chest"; severely diminished  |
|                       | bilateral air movement present.             | breath sounds bilaterally.            |
+-----------------------+---------------------------------------------+---------------------------------------+
| Skin Circulation      | Normal or isolated peripheral pallor;       | Central cyanosis refractory to        |
|                       | capillary refill <= 2 seconds.              | oxygen; mottled, cold extremities.    |
+-----------------------+---------------------------------------------+---------------------------------------+
| Heart Rate            | Marked sinus tachycardia (compensatory).    | Bradycardia (ominous sign of hypoxia).|
+-----------------------+---------------------------------------------+---------------------------------------+
| Blood Gas Profile     | PaO2 normal or mild hypoxemia;              | PaO2 < 60 mmHg on FiO2 >= 0.60;       |
|                       | PaCO2 decreased (hyperventilation/alkalosis)| PaCO2 > 50-60 mmHg; pH < 7.25-7.30.   |
+-----------------------+---------------------------------------------+---------------------------------------+
| Primary Intervention  | Supplemental O2, HFNC, CPAP, nebulizers;   | Immediate bag-valve-mask ventilation; |
|                       | noninvasive support.                        | endotracheal intubation and mech vent.|
+-----------------------+---------------------------------------------+---------------------------------------+

The Pathophysiology of Respiratory Exhaustion

A child in respiratory distress compensates by contracting accessory muscles, increasing respiratory rate to clear carbon dioxide, and increasing cardiac output via tachycardia. However, children have fewer fatigue-resistant type I (slow-twitch) muscle fibers in their diaphragms (comprising only $\sim 25%$ of fibers in infants versus $55%$ in adults). When diaphragmatic glycogen stores deplete, work of breathing collapses. The patient transitions from tachypnea to bradypnea, develops paradoxical abdominal breathing, and enters acute hypercapnic-hypoxemic respiratory failure.

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Worked Clinical Case: Pediatric Triage & Emergency Decision-Making

A 3-year-old child presents to the emergency department with acute respiratory symptoms. The initial PAT evaluation shows:

• Appearance: The child is sitting up, staring blankly, does not focus on the therapist, and fails to reach for her mother. Her muscle tone is limp. (Abnormal Appearance / TICLS)
• Work of Breathing: Extreme suprasternal and supraclavicular retractions are noted, along with inspiratory stridor audible across the room and pronounced head bobbing. (Abnormal Work of Breathing)
• Circulation to Skin: The face and extremities display pale, mottled, grey coloration. (Abnormal Circulation)

Vital Signs: HR $152\text{ bpm}$, RR $48\text{ breaths/min}$, BP $84/52\text{ mmHg}$, $\text{SpO}_2\text{ }84%$ on room air. Minimum acceptable systolic BP: $70 + (2 \times 3) = 76\text{ mmHg}$ (currently normotensive/compensated).

Interpretation & Action: Abnormal Appearance + Abnormal Work of Breathing + Abnormal Circulation = Impending Cardiopulmonary Failure. The respiratory therapist calls for immediate pediatric resuscitation backup, avoids agitating the child, prepares bag-valve-mask equipment with $100%\text{ }\text{O}_2$, and readies a $4.0\text{ mm}$ and $3.5\text{ mm}$ cuffed endotracheal tube with video laryngoscopy for urgent airway control.

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NPS Exam Traps

Exam Trap 1: The "Calming Down" Pediatric Asthmatic

On the NPS exam, a child with severe asthma who was previously agitated, screaming, and tachypneic ($60\text{ breaths/min}$) suddenly becomes quiet, sleepy, and displays a "normalized" respiratory rate of $22\text{ breaths/min}$. Candidates often mistakenly interpret this as clinical improvement from bronchodilator therapy. A decreasing respiratory rate combined with somnolence in a severe asthmatic is respiratory muscle exhaustion. It signifies acute carbon dioxide narcosis and impending cardiopulmonary arrest.

Exam Trap 2: Bradycardia as a Sign of Hypoxia

Bradycardia in a child with respiratory failure is an ominous sign and hypoxemia or inadequate ventilation must be corrected immediately. Do not assume every episode has one cause: drugs, conduction disease, hypothermia, raised intracranial pressure, and vagal stimulation remain in the differential. In the respiratory-collapse vignette, support oxygenation and ventilation first while the resuscitation team evaluates other causes and follows the pediatric bradycardia algorithm.

Exam Trap 3: The Blood Pressure Trap in Shock

Do not rely on blood pressure alone to identify pediatric shock. Compensatory vasoconstriction can preserve pressure despite impaired perfusion, and hypotension is a late, decompensated finding. Integrate heart rate, capillary refill, pulse quality, skin temperature, mental status, urine output, lactate trend, and the clinical context.

Exam Trap 4: The "Silent Chest" on Auscultation

In severe status asthmaticus, disappearance of wheeze is not reassuring when air entry, effort, or mental status worsens: airflow may be too low to generate a wheeze. Reappearance of wheeze can accompany improving airflow, but judge response from the full examination, oxygenation, ventilation, effort, and alertness rather than the sound alone.