Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Resuscitation 2015 > Gold Standards Hypothermic CA > Flashcards

Gold Standards Hypothermic CA Flashcards

1
Q

Define accidental hypothermia

A

Below 35 degrees

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Primary vs Secondary CA

A

Primary - cardiac arrest due to severe hypothermia. Better outcome - esp if no asphyxia.
Secondary - hypothermic after arrest due to other cause

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

4 methods of environmental heat loss?

A

Radiation, conduction, convection and evaporation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Survival in 15 and 5 degrees water?

A
  1. 4.5 hours

2. Less than 2 hours

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Temperature classifications for hypothermia

A

Mild: 35-32 (shivering, conscious)
Moderate: 32-28 (Reduced consciousness, not shivering)
Severe: 28-24 (LOC, present vital signs)
Cardiac arrest/low flow state: <24 (No or minimal vital signs)
Irreversible: <13.7

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Cardiovascular effects of cold (haemodynamic)

A

Initial: sympathetic response, increased catecholamines -> ^CO

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Cardiovascular effects of cold (electrical)

A

Moderate hypothermia: e.g. 28-32:

SA node spontaneously depolarises less frequently as neural conduction is decreased ->prolonged conduction intervals -> bradycardia -> Decreased CO

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

At 20 degrees what is CO at?

A

20% of normal

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Why do cold conditions lead to arrhythmias?

A

Purkinje fibres and myocardium are sensitised and increasingly irritable, especially below 30 degrees.

(AF->VF->Asystole)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What ECG changes might see?

A

Osbourne/ J waves - positive reflection at the J point - proportional to hypothermic extent.
Seen below 32 degrees, not pathognomonic.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Where else see J/Osbourne waves?

A

Hypercalcaemia, raised ICP, SAH, iodpathic VF - Le syndrome d’haissaguerre

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Respiratory system response?

A

Increased drive initially.
Reduced metabolism -> slowing of RR.

Also: increased secretions, decreased ciliary motility, impaired cough reflex - aspiration likely. Also when recovering - infection/ARDS

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Resp in relation to degree of hypothermia?

A

Mild: increased RR, alkalosis
Moderate: Low RR, acidosis, cough loss/ciliary dysfn/bronchorrhea
Severe: reduced VO2, pulmonary oedema

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

On O2 delivery graph, what way does hypothermia shift the graph?

A

Left (reduced oxygen delivery)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Longest ‘no flow’ with no adverse neuro outcome?

A

6.5 hours

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Temperature -> cerebral requirement drop?

A

Below 35, 6%/degree.
So - 28: 50%
22: 75% etc

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Hypothermia categories and expect to see neuro-wise?

A

Mild: ataxia, apathy, amnesia
Moderate: pupillary dilatation, paradoxical undressing, LOC.
Severe: no corneal reflex, no pain response

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Cold diuresis?

A

Impaired Na/K pump causes K retenion ->hyperkalaemia -> acidaemia (decreased rest drive/lactic acidosis)
Central functional hypervolaemia: due to peripheral vasoconstriction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Why would chronic alcohol use contribute to hypothermia?

A

Impaired shiver response, thermogenesis and hypothalmic degeneration

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Alcohol and hypothermia - interactions?

A

Peripheral vasodilation: worsens hypothermia.
Decreased metabolic rate: decreased clearance
LOC/failure to seek shelter

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Signs of futility in hypothermia?

A

Ice in pharynx, inability to compress the chest or if cause of arrest is: lethal injury, fatal illness or prolonged asphyxia.
Remote area - practicality of rewarming.

22
Q

What can precipitate VF when in hypothermic cardiac arrest?

A

Rough handling, intubation, etc

23
Q

Intubation in hypothermic c/a?

A

Early! Beware reduced compliance of soft tissues.

24
Q

Why is hyperventilation a risk in CPR?

A

Cerebral hypoxia due to reduced cerebral blood flow.

25
Q

What used to measure temperature?

A

Tympanic thermometers - accurate to 20 degrees.

26
Q

Why are rectal temperatures not accurate?

A

Faecal loading.

Also - rectal temperature lags by several degrees which can escalate care with hyperthermia.

27
Q

How is defibrillation adapted in hypothermia?

A

VF/VT: try three times, but not again until temp reaches 30 degrees (myocardial damage risk)
No pacing for bradycardia until normothermic (may be physiological)

28
Q

How are drug doses/administration of adapted in hypothermia?

A

Less effective due to reduced BMR.
Toxic levels can arise with same dose.
Reasonable to withhold until 30 degrees.
Same doses in ALS, but doubled intervals until reach 35 degrees.

NB - Adrenaline increases CPP, but not survival

29
Q

Prehospital re-warming procedure - mild?

A

Passive rewarming. Insulate with blankets/foil/cap and move to warm environment.

30
Q

Prehospital re-warming procedure - moderate-severe?

A

Active rewarming - apply chemical heat packs to trunk.

If unconscious, and airway unsecure, arrange the insulation around the patient in a recovery position. Reheating with warm IV and warm humidified air will not be feasible.

Intensive active rewarming must not delay transport to hospital where advanced rewarming techniques and monitoring are available.

31
Q

Signs of cardiac instability in Stage II-IV?

Action?

A

SBP <90, centricular arrhythmias, core temp <28 etc

Action: Transfer to ECLS centre

32
Q

Difficult extrication rules?

A

Intermittent CPR if not possible for continuous.
Below 28 degrees: 5 mins with, 5 mins without.
Below 20 degrees: 5 mins with, 10 mins without.

33
Q

Not dead until you’re?

A

Warm and dead

34
Q

ECMO location?

A

Femoro-femoral: easier, reduces heat loss compared to aortic-right atrial.

35
Q

Internal re-warming if no ECMO?

A

Bair Hugger
Warm IV fluids
Warm inspired O2
Lavage - use warmed hartmanns solution; gastric, bladder, peritoneal or pleural.
Warmed peritoneal dialysate (4L) via Peritoneal Catheter. Leave for 15 mins to exchange heat before draining.
Pleural requires apical and basal chest drain on each side. “L of warmed hartmanss is infused into each hemithorax via apical drain and removed after 15 mins.

High volume renal hemofilter

36
Q

Define slow rewarming

A

Increases temp by 0.3-1.2 degrees/hour. (17-30 kcal/hour)

37
Q

What temperature are IV solutions heated to?

A

45 degrees (17 kcal/hour)

38
Q

What temperature are inspired o2?

A

0.7 degrees/hour (30 kcal/hr)

39
Q

How quickly do warmed blankets rewarm?

A

0.9 degrees/hour

40
Q

Define moderate rewarming

A

3 degrees/hour

Gastric lavage, 65 degree IV solutions and 45 degree peritoneal lavage

41
Q

Define rapid rewarming

A

Levels higher than 100 kcal/hour

Thoracic lavage, cariodpulmonary bypass, ECMO and AV dialysis

42
Q

How quick is endogenous rewarming?

A

300 kcal/hour

43
Q

Problem with warm water baths?

A

Core temperature after drop and CV collapse - peripheral vasodilation

44
Q

How quickly should we rewarm?

A

Aggressively: rapid rewarming

45
Q

What do you do if you get ROSC?

A

Re-warm to mild hypothermia - avoid overshooting.

When CV stable - re-warm aggressively

46
Q

How can you avoid rewarming shock?

A

Volume load to maximise CO

47
Q

Criteria of futility if no ROSC at >32 degrees

A
  • Potassium over 10mmol/l
  • Severe trauma
  • Prior cardiopulmonary, renal or neuro disorders
48
Q

Gold standard for rewarming?

A

ECMO/bypass

49
Q

Is defibrillation more or less effective in hypothermia?

A

Less

50
Q

What is the gold standard for temp reading?

A

oesophageal - closest to core

Resuscitation 2015 (31 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions