Paramedic Basics

- The relationship between the ECG, cardiac myocyte action potential and mechanical movement of the heart

This came up today whilst teaching, the difficulty bringing together these three different concepts and making them apply to the one patient

- ECG: P wave, PR segment, QRS complex, ST segment, QT interval and T wave
- Cardiac myocyte action potential: Phase 0, 1, 2, 3 and 4, the associated movement of sodium, potassium and calcium ions. [Note cardiac pacemaker action potential is not featured]
- Mechanical: atrial contraction and relaxation, ventricular contraction and relaxation, and the relation to a palpable pulse

The relationship between the ECG and mechanical activity is essential for all paramedics to understand. The relationship between the ECG and cardiac action potential is very important, especially if you want to give anti-arrhythmic drugs to the patient

Please excuse the quality as this was a quick mock up during class - I will try to make a clearer on and post in the future

- Critical Asthma

Around 11% of Australians live with asthma - that’s 2.8mil people! Asthma exacerbations can range from mild to critical, and in the worst cases can result in death. Between 3-10% of these people will have severe disease.

Critical asthma is a term which refers to the sudden onset of severe asthma - it’s a time critical emergency which can cause deaths. In 2016 a thunderstorm asthma event caused thousands to be hospitalized and led to 10 deaths. In response to that, and informed by the evidence gained a new CPG for treating critical asthma was developed

The flow chart here demonstrates the downward spiral of deterioration for patients with critical asthma. Increased WOB (slight difficult to see on the flow chart sorry!), muscle fatigue, decreased expiratory time and gas trapping leads to a repetitive cycle. Hypercapnia, hypoxia and haemodynamic compromise follow.

CARE OBJECTIVES
✅ Early administration of adrenaline (IM/IV) in patients not responding to nebulised therapy
✅ Utilise an obstructive ventilation strategy and allow permissive hypercapnia

PARAMEDIC MANAGEMENT:
🚨 Administer nebulised bronchodilators (treats bronchospasm)
🚨 Oral steroid (treats mucosal oedema - slower acting)
🚨 Maintain SpO2 > 92% (titrate the flow through the neb mask or use ETCO2 nasal prongs)
🚨 Administer IM Adrenaline (alpha/beta adrenergic action = bronchodilation, decreased mucosal oedema, increased venous return and cardiac output) to patients critically unwell or not responding to nebs
🚨 If no response to IM Adrenaline, administer IV Adrenaline
🚨 MICA can commence an Adrenaline infusion and BiPAP
🚨 If patient becomes unconscious - commence BVM ventilation with obstructive strategy

💔 ASTHMATIC ARREST 💔
- Allow 1/60 apnoea to release gas trapping
- Prepare for cardiac arrest management
- If still in arrest after 1/60: commence medical cardiac arrest
- If pulse returns with no BP: MICA administer IV Adrenaline and fluid
- If pulse returns with BP: treat as above for critical asthma

- Shoulder Dystocia

Shoulder dystocia is a time critical emergency which anyone who delivers babies needs to know about. Occurring when the baby fails to deliver because it’s shoulder is stuck, there is a short window to resolve SD before permanent damage or death can occur

INCIDENCE:
Occurs in 1% of all vaginal deliveries
Some correlation with baby’s size, however 50% of SD occurs in normal birth weight
Some predictive risk factors however 50% of SD have no risk factors

🚨 SO IF YOU’RE A PARAMEDIC YOU NEED TO BE ALL OVER THIS!

CLINICAL PICTURE
- head down delivery
- head delivered but not advancing
- head may be retracting (turtle sign)
- head to body time > 60 sec

PARAMEDIC MANAGEMENT
📞 Immediately request backup and commence specialist telehealth consult
🚨 Advise all on scene of SD, and inform mother
🦵 Position mum with buttock on edge of bed if possible, and provide *gentle* downward traction on the baby

If still not delivered, move through these manoeuvres

1️⃣ McRoberts Position
“Knees to nipples” - helps open up pelvis and increase pelvic outlet diameter

2️⃣ Suprapubic Pressure (while still in McRoberts Position)
Hands in CPR style grip, placed at a 45 degree angle to baby’s back. Apply constant pressure for 30 seconds (helps reduce bisacromial distance and rotate baby more oblique).

After 30 seconds, commence a gentle rocking motion to try and achieve the same goal.

3️⃣ Gaskin Position
“All fours” - helps release the posterior shoulder, which is sometimes the culprit. Be aware that whilst moving position baby may suddenly be released!

🛑 If these techniques are not successful, discuss with PIPER when to abandon the attempt and transport the patient. They may also direct you to perform additional maneuvers

PEARLS:
- practice practice practice these techniques, even if you don’t have access to a training mannequin
- communication to parents and other paramedics on scene is essential
- escalate care early!
- be prepared to perform resuscitation once baby is delivered
- don’t forget to monitor mum closely after delivery (consider a second crew!)