LVH, LAD, GCS, RSI

1. How do you diagnose LVH and LAD from ECG?

2. A patient came to you with GCS 7/15(E2V2M3). What is your action? Define GCS.

3. What is RSI? List out the sequence. 

1. Left Ventricle Hypertrophy (LVH)

Romhilt-Estes point score system ("diagnostic" >5 points; "probable" 4 points):
In my opinion it is a rather complex diagnostic criteria.

1. ECG Criteria Points Voltage Criteria (any of):
   
   • R or S in limb leads ≥ 20 mm
   • S in V1 or V2 ≥ 30 mm
   • R in V5 or V6 ≥ 30 mm
2. ST-T Abnormalities: ST-T vector opposite to QRS without digitalis
   ST-T vector opposite to QRS with digitalis
3. Negative terminal P mode in V1 1 mm in depth and 0.04 sec in duration (indicates left atrial enlargement) 3
4. Left axis deviation (QRS of -30° or more) 2
5. QRS duration ≥0.09 sec 1
6. Delayed intrinsicoid deflection in V5 or V6 (>0.05 sec) 1
7. Other voltage-based criteria for LVH include:
   
   • Lead I: R wave > 14 mm
   • Lead aVR: S wave > 15 mm
   • Lead aVL: R wave > 12 mm
   • Lead aVF: R wave > 21 mm
   • Lead V5: R wave > 26 mm
   • Lead V6: R wave > 20 mm

Criteria of LVH on ECG given by my therapy teacher:

• Left axis deviation (LAD)
• R_V5 taller than R_V4
• R_V5/V6 + S_V1 > 35 cm (Sokolow-Lyon index)
• R_I + S_III > 25 cm
• (R_I - S_I) + (S_III - R_III) > 17 cm (Levis index)
• R_aVL > 11 cm
• ST depression in left leads (I, aVL, V5, V6)
• T inversion in left leads (I, aVL, V5, V6)

The most important is the Sokolow-Lyon index, cause it has high specificity, but low sensitivity, e.g. in obese patient the voltage of the ECG waves might be dampen down.

So we should also look for left ventricle strain pattern.

• Left leads (I, aVL, V5, V6) :T-wave inversion + ST-depression
• Right leads (III, aVF, V1, V2) : ST-elevation

NB! T-wave inversion can be sign of ischemic damage to the myocardium, but the pattern is different.

• In LV strain pattern, gradual down-slope of the T-wave + sudden up-slope of the T-wave.
• In LV ischemia, symmetrical downslope + up-slope of the T-wave. 
• Compare with the ECG of the ischemia below.

But it is not absolute, and cardiac enzyme e.g. troponin should always be checked to rule out ischemia.

Left Axis Deviation (LAD)

• R_I > R_II > R_III.
• Upward deflection of QRS-complex in I.
  downward deflection of QRS-complex in III.

2. GSC is Glasgow Coma Scale.

1. Secure ABC of life support.
2. O2, IV access. Consider intubation since GCS < 8.
3. Check vital signs: BP, PR, RR, temperature.
4. Check for any external trauma especially cervical spine trauma.
5. Check for any sign of increased ICP (ophthalmoscopy).
   Check for meningism. (NB! Don't move neck if cervical spine trauma)
6. Investigation: FBC, BUSE, ESR, CRP, LFT, Creatinine, ABG, DXT, toxicology screening.
   CXR, ECG, neuroimaging (CT/MRI), LP (if meningism + no increased ICP)

Management will depend on the cause. 

3. RSI is Rapid Sequence Intubation / Induction

I am not quite sure about this procedure especially the medication and dosage, but I'll try answer with what I read on the Internet. RSI refers to the pharmacologically induced sedation and neuromuscular paralysis prior to intubation of the trachea. RSI is generally used in an emergency setting.

1. Administer 100% oxygen via a nonrebreather mask for 3 minutes for nitrogen washout.
2. Administer a rapidly-acting induction agent IV to produce loss of consciousness.
3. Administer a neuromuscular blocking agent IV immediately after the induction agent.
4. Rapid placement of an endotracheal tube (ETT) between the vocal cords, while the cords are being visualized with the aid of a laryngoscope. 

One important difference between RSI and routine tracheal intubation is that the practitioner does not manually assist the ventilation of the lungs after the onset of general anesthesia and cessation of breathing, until the trachea has been intubated and the cuff has been inflated. 

Another key feature of RSI is the application of manual pressure to the cricoid cartilage, often referred to as the "Sellick maneuver", prior to instrumentation of the airway and intubation of the trachea to prevent regurgitation of gastric contents. However this technique may impede laryngeal view. 

Do share with us more regarding this topic =).

--- UPDATE ---

Answer.

1. LVH: left ventricular hypertrophy. One of the easiest and fastest way is the see V1 and V6. The sum of big box (with 5 small boxes) of R wave in V6 and S wave in V1 must exceed 7 in LVH.

2. GCS: Glascow coma scale. Total number is 15/15(E4V5M6).

E: Eye

• 4= eyes open spontaneously
• 3= eyes open in response to call
• 2= eyes open in response to pain stimuli
• 1= no eye opening

V: Verbal

• 5= oriented
• 4= confused
• 3= inappropriate words
• 2= incomprehensible words
• 1= no voice

M: Motor

• 6= obey commands
• 5= localizes to pain
• 4= withdraw to pain
• 3= abnormal flexion to pain stimuli
• 2= abnormal extension to pain stimuli
• 1= no movement

When the patient comes to us with GCS< 8, theoretically intubation is needed to maintain the airway and also for cerebral protection in case of traumatic brain injury. But first, we must assess the vital sign first. 

Intubation is not needed in case of temporary hypoglycemia. A patient with hypoglycemic attack can have poor GCS. A patient with recurrent massive stroke does not need intubation if GCS is always low all the while. What I want to conclude is that a poor GCS does not necessarily need intubation unless it is indicated and vice versa.

3. RSI: rapid sequence intubation.

It must be done in sequence. (with several "P"s)

1. Preperation

• We must firstly prepare the patient with good position and instruments for intubation. Things to prepare: medications, ambu bag, bag-valve-mask, yankeuer, suction tube, laryngoscope, endotracheal tube (ETT) with appropriate size, K-Y jelly (lubricant gel), oral airway.
• RSI must be done with helps. A team must be formed of a leader and few assistants. A assistant must be selected mainly only to perform cricoid pressure.
• Vital sign monitoring must be ready - you need to observe BP, PR, SPO2, heart beat rhythm during RSI. 

2. Pre-oxygenation

• Bagging can be done with ambu bag and bag-valve-mask. 
• Bagging is not necessarily if there is still spontaneous breathing and we only apply the ambu bag on the mouth without bagging. 
• SPO2 must be maintained at least 99%.

3. Pre-medication

• There are few sedative medications that are mentioned in literature. I only mention common medication. 
• Here, we use Midazolam (0.1-0.3mg/kg/dose). 
• Atropine can be added if there is bradyarrhythmia.

4. Paralysis

• There are mainly 2 types of paralysing medication we use to paralyse the airway for easy intubation. There are Succhynilcholine and Rocuronium. 
• We often use S-choline (1-1.5mg/kg/dose). This medication often would cause muscle fasciculation and it is the main sign that we can see after introduction. The fasciculation will trasmit from head till toe and once it reaches the toe, it is time for intubation. Of cause, each drug has its own side effect and neither the patient can escape from this drug. S-choline can cause raised intracranial pressure, bradycardia and hyperkalemia. Please mind that we must avoid this drug for patient with bradycardia, traumatic brain injury, brain tumor, ESRF (end stage renal failure) and so on.
• In view of S-choline possible adverse effect, Rocuronium would be the substitute. Its usual dosage is 1-1.2mg/kg/dose. After 1 minute of introduction, we are ready to intubate. Of course, due to its prolonged paralysing effect, it is not the first line drug unless it is indicated.

5. Protection

• Once we introduce sedation and followed by paralysing agent, our assistant needs to perform cricoid pressure. Remember that we can only release the cricoid pressure after successful intubation.
• Please find out what is cricoid pressure and how to do it.

6. Positioning

• We need to position the head and the mouth for intubation. 
• Please find out how you would like to place the head in order to visualize the vocal cord.

7. Placement of tube

• Please remember that we always use our left hand to hold the laryngoscope. The blade should face towards the patient. Use our dominant hand to open the patient's mouth. With correct position and cricoid pressure, this step would be possible. 
• The usual size of ETT is 7-7.5mm for adult. ETT with size 8mm is sometimes needed for huge adult patient. ETT is often anchored at 21-22cm at mouth angle. 
• If ETT is inserted too deep, we can create pneumothorax. 
• If ETT is inserted too shallow, it can be dislodged or the patient can have insufficient oxygen supply. 
• After intubation, ETT must be secured. By auscultating the lungs and epigastric region, we can hear the lung breathing sound if the ETT is placed into the airway; otherwise, we can hear sound at epigastric region if the ETT is placed into the esophagus. Esophageal intubation can cause gut perforation and ETT must be taken out and repeated intubation is needed.

8. Post-intubation management

ICU admission must be arranged. CXR must be done. Gauze must be applied over the eyes to avoid eye dryness after intubation. After intubation, 3 things we will see.

• SPO2: SPO2 will remain 100% after intubation. If SPO2 drops, then there is either something not right with the placement of ETT or other causes, e.g pneumothorax.
• Chest expansion with out-in going vapor in ETT: Chest will depress with each out-going vapor from ETT.
• CXR: CXR must be done after intubation to ensure the ETT is in situ.

Doctors must know how to intubate and to perform RSI. It is compulsory!