CPC: Altered Mental Status

Edward Ng, D.O., M.S.

Francis Villanueva, D.O.

HPI

This is a 92-year-old male with significant medical history including CKD, hypertension, dementia, hypothyroid, BPH, brought in by EMS from the nursing home with altered mental status. Per EMS, patient is at baseline A&O x3 which was how he was this morning. Patient arrived to the ED at 0945, and 15 minutes prior to arrival patient was being fed when he abruptly began having a “seizure” lasting about 1 minute. Patient was altered and confused and an apparent postictal state. On transport patient had bradycardia down into the 30-40s and 0.5 atropine was given which brought his heart rate back up into the 60s. Patient's blood pressures were also in the systolic 70s as low as 60s. Patient is not responding verbally and no history is obtainable from him.

ROS: unable to obtain 2/2 acuity of condition/patient unresponsive

Physical Exam

Constitutional: Ill-appearing, frail. Non-verbal, not responding to questions or commands
HEENT: NCAT, external ears normal
Eyes: Deviated to the left, reactive to light
Neck: No midline cervical tenderness or step-offs
Cardiovascular: Bradycardic, regular rhythm
Respiratory: Coarse breath sounds, no respiratory distress
Abdomen: Flat, non-distended
MSK: Moderate BLE edema, no deformities
Skin: Warm, dry, no obvious rash, right heel wound with good granulation tissue
Neuro: GCS 10, A&Ox0, moves all extremities but not following commands. Eyes deviated to the left, right-sided hemineglect

ECG

Ventricular rate: 49

Incomplete LBBB

No STE/STD

Is this patient having a stroke?

AMS
Gaze deviation
Unable to assess neurological function
Stroke 1 activated

Imaging

CT Head Stroke Alert Level 1 WO Contrast
- No acute intracranial abnormality.
- White matter hypodensities are unchanged compared to prior examination and most compatible with chronic small vessel ischemic changes.
CTA Head and Neck W Contrast Level 1
- No high-grade stenosis, occlusion or vascular malformation within the intracranial vasculature.
- Mostly soft plaque in the left carotid bulb with less than 50% luminal narrowing.
- Otherwise unremarkable CTA of the neck without high-grade stenosis or occlusion. Dr. Ng notified of findings via telephone by Dr. Saucier at 11:01 AM on 07/13/2021.
- Partially visualized moderate left pleural effusion.

Chest X-Ray

Poor inspiratory effort. Overlying leads and wires. Heart size prominent unchanged. Calcification of aortic arch. Linear scarring left lung base. Reticular opacities both lung bases likely atelectasis. Confluent interstitial and groundglass opacities perihilar regions on the right lung base could represent areas of atelectasis and or developing interstitial edema. Probable small left-sided pleural effusion. Linear lucency at the right neck could be artifactual. Follow-up advised. No pneumothorax.

Labs

CBC

CMP

Lactic Acid

Blood Gas

Troponin, PT, PTT, Magnesium

Urinalysis

What test do we order next?

Click to see answer

Diagnosis: Myxedema Coma

Hypothyroidism

PLUS

Mental status change or coma

PLUS

Hypothermia/bradycardia

PLUS

Precipitating stressor

Our patient:

Temp: 86.5ºF (30.3ºC)

HR: 53

Free Triiodothyronine: 0.8 pg/mL

Precipitating Factors

Common inciting events include
- Sepsis
- Volume depletion
- Cold exposure
- CHF
- GI bleeding
- Medications

Epidemiology

Women show an incidence >4-fold higher than men
Most cases are geriatric patients
More than 90% of cases occur in the winter
Most common cause of hypothyroidism is Hashimoto’s thyroiditis
- Over-response to hyperthyroidism
- Thyroidectomy
- Head and neck CA radiation
- Meds
Mortality ranges from 30-60% regardless of adequate treatment
- Most commonly 2/2 delays in dx and tx of condition

Pathophysiology

Hypothalamus secretes TRH
TRH stimulates TSH production in the pituitary gland
Thyroid gland produces T3 and T4
T3 and T4 provide negative feedback on hypothalamus and pituitary gland

Too little T3 → hypothermia and negative inotropy
- Body compensates by peripheral vasoconstriction
  - Diastolic hypertension and subsequent low cardiac output
  - RAAS slows → less salt retention in the kidney → decrease in circulatory volume
- Low T3 also causes changes in vascular permeability → anasarca and transudative effusions
Respiratory failure can develop rapidly
- Pleural effusion → decreased lung volumes → hypoventilation →hypercapnia, hypoxia
- Myxedema of airway structures → airway resistance → hypoventilation
- Respiratory muscle dysfunction → respiratory dyssynchrony → hypercapnia → increased somnolence and worse AMS → respiratory failure

Renal
- Impaired 2/2 decreased CO and peripheral vasoconstriction
  - Can cause hyponatremia due to impaired free water excretion
GI
- Gastric atony, decreased peristalsis, ileus → constipation
- Third spacing → ascites
Hematology
- Anemia is common
  - Decreased oxygen requirement
  - EPO decrease
- Acquired vWB syndrome can occur
  - Decreased synthesis of vWB factor
Endocrine
- Often develop concomitant adrenal insufficiency due to secondary hypopituitarism

Work Up

Thyroid labs
- TSH - elevated
- Free T4 - low normal to low
- Serum cortisol
CBC
- leukopenia
CMP
- Creatinine can be elevated
- hypoglycemia
- hyponatremia
VBG can show hypoxemia and respiratory acidosis 2/2 hypercapnia
ECG
- Rhythm abnormalities; sinus bradycardia, conduction blocks
- QTc prolongation
- Low voltage
Evaluation for triggers
- Infectious work up (CXR, blood cultures, UA, LA)
- Head CT
- LP

Treatment

ABCs
- Rewarm the patient with bair hugger, warm blankets, etc
- IV fluids for hypovolemia, NS/hypertonic if patient severely hyponatremic
Treat underlying etiology
- I.e. abx for sepsis
Hydrocortisone 100mg IV q8h
Levothyroxine (T4) 100-500mcg IV load, then 50mcg qd
- Pressors will not work unless you give thyroid hormone first
Liothyronine (T3) 5-20mg IV
Airway considerations - use caution
- Low lung volumes and hypoventilation

Oxygen reserve much lower even with adequate pre-oxygenation

Prone to much faster desaturations

- Airway edema, macroglossia

Airway collapse, making direct laryngoscopy difficult

Disposition: ICU

References

Cimino-Fiallos, Nicole. “Decompensated Hypothyroidism.” EMRAP.org, https://www.emrap.org/corependium/chapter/recq2Rb31DrFS9QWD/Decompensated-Hypothyroidism#h.yzr2gkact84v.

Farkas, Josh. “Decompensated Hypothyroidism (‘Myxedema Coma’).” EMCrit Project, 11 Feb. 2023, https://emcrit.org/ibcc/myxedema/#organ_systems.

Eledrisi, Mohsen s. “Myxedema Coma or Crisis.” Practice Essentials, Pathophysiology, Epidemiology, Medscape, 29 June 2022, https://emedicine.medscape.com/article/123577-overview#a5.