chapter 12 pt6 Flashcards
causes f peri-operative cardiac arrest ?
general anaesthesia - airway mx
hypovolemia
cardiac problems
complication of central venous access
primary arrest rhythms in preoperative setting ?
a-systole
in contrast to arrests due to other causes asystole has the highest chance of survival
how to rescue someone drowning ?
attempt to safe the drowning without entry to water
if entry to water essential - take buoyant rescue ad flotation device
safer to enter water with two rescuers
remove pt from water [rpomptly - pt that drowned sustaining spinal injury very low
pulsless or apnoeic = remove them from water quickly as possible and attempting to limit neck flexion and extension
KEEP IN HORIZONTAL POSITION
submersion time that leads to good and bad clinical outcome
5-10mins = good
more than 25 = bad
except children submerged in ice cold water
hypothermia can cause positive effects on brain and vital organs - if deep hypothermia develops before hypoxia
at 18 degrees brain can tolerate periods of circulatory arrest ten times longer than at 37 degrees
search and rescue guidance on timing ?
efforts should be carried for search and rescue at 30 mins and 60 mins of submersion
up to 90 mins extension if children or immersed in cold icy water
what is the initial resus protocol once then from water ?
check airways
breathing - atonal breathing
give 5 INITIAL VENTILATIONS WITH OXYGEN IF AVAILABLE
VENTILATION ONLY RESUS IS CRITICAL AND MAY ITSELF LEAD TO ROSC
=======
if regurg of stomach contents and swallowed water preventing ventilation - turn the person on their side and remove regurgitated material
========
no response to initial ventilation - then start CPR
= compression only cpr is avoided
======
even if person have foaming from mouth mixing air with water and surfactant = continue rescue breaths until ALS provider comes
=====
early tracheal intubation
======
decompress stomach with gastric tube
=======
dry person chest before putting defibrillates pads
======
if prolonged immersion - most people hypovolemic due to hydrostatic pressure of water on body is removed
primary cause of cardiac arrest in pt that drown is ?
hypoxia
drowning mechanical ventilation setting ?
set positive and expiratory pressure
5-10cm H20
however PEEPA OF 15-20 may be required for every hypoxia
post resus complications in drowning ?
ARDS
PNEUMONIA - prophylactic abs not of benefit
neurological outcome depends on duration of hypoxia
neurological - dependant on duration of hypoxia
what is hypothermia ?
less than 35 degrees
core temp:
mild =35-32
moderate = 32-28
severe = less than 28
stages hypothermia ?
stage 1 = mild
conscious , shivering
stage 2 = moderate
impaired consciousness without shivering
stage 3 = severe hypothermia
unconscious , vital signs present
stage 4 = cardiac arrest or low flow state
no or minimal vital signs , core temp <24
stage 5 = death due to irreversible hypothermia
most at risk for hypothermia ?
elderly and children
how to measure core temprature ?
lower third of oesophagus most accurate - but measurement can only be performed int hose who’ve got a secure advanced airway
tymapnic measurement = considered lower than core temp
once in hospital use constant site to measure temp - BLADDER AND RECTAL NOT RECOMMENDED
what should we be aware when diagnosing death in hypothermia ?
hypothermia can produce very slow , small volume , irregular pulse and unrecordable blood pressure= no signs of life = hypothermia stage 4
so therefore no signs of life alone are unreliable for declaring death
how to change the als protocol in hypothermic patients ?
check for signs of life upto 1 min
capno, echo , near infrared spectroscopy or US with doppler to know whether there is cardiac output
hypothermia can make the chest wall stiff making chest compression and ventilation difficult - mechanical chest compression
for those with core temp less than 28 degrees - give 5 min of CPR
alternating with periods of no cpr for 5min or less CPR
patient core temp less than 20 degrees
alternate between 5 mins of CPR and up to 10 min without CPR
once CPR under way confirm hypothermia
=====
if VF is detected and if still refectory to three attempts of shock delay further attempts till 30 degree is reached
========
hypothermic heart unresponsive to cardiocative drugs = electrical pacing and defib
WITHOULD ADRENALINE AND OTHER DRUGS UNTIL TEMP ABOVE 30 DEGREES
as normothermia reached >35 degrees - use standard drug protocols
once 30 degrees - intervals between drug doses should be doubled eg adrenaline every 6-10 mins
======
REWARMING
stages 1 = passive rewiring
patient can shiver
wool blankets
aluminium foil
warm environment
stages 2-4
chemical heat packs to the trunk has been recommended
pre arrest rewarm = active external methods - forced warm air and warm IV infusions , force peritoneal lavage
deteriorating hypothermic and cardiac arrest due to hypothermia - rewarming performed with extra corporeal ;ice support - using echMO IN PREFERENCE TO CARDIOPULMONARY BYPASS
