Hypovolemic Shock

Question 1

what is the main artery used to measure BP?

Answer 1

brachial

Question 2

describe Ohm’s law

Answer 2

pressure = flow x resistance

Question 3

compare stage 1 HTN, stage 2 and HTN crisis

Answer 3

stage 1: 130-139/80-89
stage 2: >140/>90
crisis: >180/>120

Question 4

what is the MAP and what eqaution is used to determine this?

Answer 4

MAP= CO x systemic vasc resistance, equation= DBP + (pulse pressure/3)

Question 4

how do SNS and PNS reg arterial pressure?

Answer 4

Baroreceptors

Question 5

how does pit gland reg arterial pressure?

Answer 5

vasopressin

Question 6

how does kidney reg arterial pressure?

Answer 6

renin angiotensin aldosterone system via Na+ reabsorption and water retention

Question 7

how do adrenal glands reg arterial pressure?

Answer 7

catecholamines, aldosterone and glucocorticoids

Question 8

how does the heart reg arterial pressure?

Answer 8

ionotropic, chronotropic and atrial natriuretic peptide

Question 9

What effect does increased baroreceptor activity have on BP?

Answer 9

increased baroreceptor activity increases PNS activity -> reduction in BP

Question 10

describe baroreceptors

Answer 10

nerve endings that sense artery wall stretch

Question 11

what is the RAAS and what effect does it have on BP?

Answer 11

Renin angiotensin aldosterone system, increases BP and systemic vasc resistance

Question 12

which has a faster response and why: baroreceptors or RAAS?

Answer 12

Baroreceptors have a faster response as RAAS is dependent on hormonal changes inducing transcription of denes which can take hours

Question 13

what effect does angiotensin II have?

Answer 13

vasoconstriction, increase Na+ reabsorption and water retention, stimulates further aldosterone release and activates SNS

Question 14

describe reasons for vasopressin release

Answer 14

released from post pit in response to: increase in plasma osmolarity, reduction in blood vol, increases angiotensin II = increased BP

Question 15

how does vasopressin increase BP?

Answer 15

V1:constriction of blood vessels and V2:kidney fluid reabsorption

Question 16

describe atrial natriuretic peptide and what causes it’s release

Answer 16

ANP is a vasoactive peptide released from the atria in response to a ride in atrial pressure linked to venous pressures = lowering of BP

Question 17

how does ANP reduce BP?

Answer 17

through vasodilation, inhibition of Na+ reabsorption -> diuretic effect

Question 18

how does the adrenal gland affect BP?

Answer 18

catecholamines such as epi and nor epi -> increase in HR and vasoconstriction, aldosterone acts with RAAS locally causing vasoconstriction, glucocorticoids cause vasoconstriction

Question 19

what changes occur to baroreceptors in pregnancy?

Answer 19

increase in sensitivity

Question 20

what changes occur to RAAS in pregnancy?

Answer 20

enhanced activity

Question 21

decreased vasc responsiveness to which hormones occurs in preg?

Answer 21

angiotensin II, norepi and vasopressin

Question 22

what changes occur to ANP in preg?

Answer 22

increase by 40%

Question 23

list the diff types of shock

Answer 23

hypovolemic, cardiogenic, distributive, obstructive

Question 24

define haem shock

Answer 24

EBL >500ml within 24 hours of birth

Question 25

what needs to be considered with EBL

Answer 25

pt prior Hb, total blood vol (100ml/kg)

Question 26

define APH

Answer 26

any bleeding from genital tract post K24 and prior to birthp

Question 27

list causes of PPH

Answer 27

tissue, trauma, tone, thrombin, laceration

Question 28

list risk factors for haem shock

Answer 28

placental disorders, multiple preg, PET, GHTN, prev PPH, asian, obesity, anaemia

Question 29

list risk factors for haem shock in labour

Answer 29

febrile, IOL, CS, retained tissue, op vaginal delivery, macrosomia, mat age >40, epis

Question 30

describe stage 1 of hypovolemic shock

Answer 30

pre shock: compensatory mechanisms with increased sym tone-> increased HR, cardiac contractility and peri vasoconstriction, eaerly changes in vitals with loss of 10% BV, mildly elevated BP

Question 31

describe stage 2 of hypovolemic shock

Answer 31

shock state: BV cont decrease 25-30% of BV -> shock state with drop in SBP, tachy, oliguria, O2 deliv to vital organs inadeq-> lactic acidosis, blood flow redirected to brain and heart = propagates tissue ischemia and worsens lactic acidosis

Question 32

describe stage 3 of hypovolemic shock

Answer 32

untreated -> haemodynamic compromise, refractory acidosis, reduction in CO = MOF and death, avg time from onset 2hrs

Question 33

list components of active management third stage

Answer 33

uterotonics and fundal massage

Question 34

list the components of managing an acute incident

Answer 34

recognition, communication, resus, monitoring, management, theatre