The most common reasons for a MET call
o Hypoxia
o Hypotension
o Altered conscious state
o Tachycardia
o Tachypnoea
Common underlying causes of MET calls
o Sepsis,
o Cardiogenic shock
o Pulmonary oedema
o Arrhythmias
When do compensatory mechanisms occur
When the body detects decreased oxygen delivery at the tissues or a reduction in
cardiac output
Types of compensatory mechanisms
o Mechanisms for effective blood vol = vasoconstriction, decreased renal losses of
fluid
o Mechanisms to optimise cardiac performance = increased HR & contractility
o Preferential perfusion of vital organs
Vital signs that detect reduced oxygen delivery
o Compensation (↑HR and ↑RR) - Increased HR = reduces ventricular filling time,
increased myocardial O2 demand, a compensatory process started by SNS to
preserve CO.
o Decompensation (↓SpO2 and ↓BP)
o Changes in level of consciousness indicate poor energy production and as such a
reduction in level of consciousness should be accompanied by a check of the
patients BGL. Sudden fall in GCS >2 elicit concern
Respiration metabolic workload
Normal respiration metabolic workload is approx. 6%; RR of +30 increases metabolic
workload to 30%
Normal urine output
o >0.5mls/kg/hr
Compensatory processes - SNS activation
,↓baroreceptor stimulation → SNS nerves & adrenal medulla stimulated→
catecholamine's released → systemic vasoconstriction, ↑ HR and myocardial
contractility = ↑CO and BP
Pharmacological treatments: beta blockers, GTN
Compensatory processes - neuroendocrine
↓ arterial pressure → stimulates antidiuretic hormone secretion from pituitary →
vasoconstriction = ↑ systemic vascular resistance, BP and venous return (preload) =
↑ CO
Pharmacological treatments: Frusemide
Compensatory processes - RAAS activation
↓renal perfusion & ↑ SNS stimulation → renin released tostimulate angiotensin 1 →
converted to angiotensin 2 by Angiotensin converting enzyme → arteriolar
constriction & aldosterone release by adrenal cortex → kidneys conserve Na+ and
H2O to increased preload
Pharmacological treatment: Frusemide, Angiotensin converting enzyme inhibitors
The Paediatric Assessment Triangle
o the child' s appearance,
o work of breathing
o circulation to the skin
provides clinicians with a rapid hands-off 30-second (approximately) assessment
that can be completed prior to the hands-on primary survey
The Paediatric Assessment Triangle - appearance
o tone (includes whether the child moves spontaneously, resists being examined,
sits or stands (age appropriate)
o interactiveness (includes whether the child appears alert and engaged with
clinicians/caregivers, interacts with people and environment, reaches for toys,
objects)
o consolability (includes whether the child stops crying with holding/comforting by
caregiver or has differential response to caregiver versus examiner) look/gaze
(includes whether child makes eye contact with clinician, tracks visually) speech/cry
(includes whether the child has a strong cry/uses age-appropriate speech).
The Paediatric Assessment Triangle - breathing
o abnormal airway sounds (including snoring, muffled or hoarse speech, stridor,
grunting, wheezing) abnormal
o positioning (sniffing position, tripoding or preference for seated posture)
o retractions (supraclavicular, intercostal or substernal retractions, head bobbing in
infants)
,o flaring of the nares on inspiration.
The Paediatric Assessment Triangle - circulation
o pallor (white or pale skin or mucous membranes)
o mottling (patchy skin discoloration due to varying degrees of vasoconstriction)
cyanosis (bluish discoloration of skin and mucous membranes).
Interventions for patient deterioration
what is going to happen, what is happening. About services available for support.
Continual and on-going support. Answering their questions. CPR with senior nurse
Haemodynamic responses - neonate/child
Neonate - less than a month, 2L circulating blood volume,
high HR to support metabolic demand, lower arterial bp, no lifestyle damages/ less
vasoconstrictive capabilities, diminished reserve due to immaturity of the cardiac
muscle
Haemodynamic responses - older adult
The decrease of elasticity of the arterial vessels with aging may result in chronic or
residual increases in vessel diameter and vessel wall rigidity, which impair the
function of the vessel. Factors that contribute to the increased wall thickening and
stiffening in aging include increased collagen, reduced elastin, and calcification.
The valves also tend to become stiff and incompetent.
SaO2
arterial oxygen saturation
PaO2
partial pressure of oxygen
Vital signs
Aerobic respiration
Turns glucose and oxygen into water and carbon dioxide
o The energy from this reaction produces ATP
o For this to occur the cells require oxygen delivery to the cells
Anaerobic respiration
Energy can be produced without oxygen
o This a less efficient form of metabolism - alteration of cell function
o It produces waste products such as Lactic Acid
o Some cells can not produce energy anaerobically so if oxygen delivery is
compromised then the cells do not function: the Brain.
Arterial oxygen range normal
, = 80-100mmHg
o Requires a patent airway, functioning lung tissue, gas exchange and haemoglobin
to carry oxygen
o A reduction in oxygen delivery results in higher RR. Sp02 >90% to avoid hypoxia
Cardiac output
Stroke Volume (amount pumped with each beat) x Heart Rate
o Requires: Good volume, A functioning pump and is dependent on peripheral
vascular resistance (vasoconstriction/vasodilation)
o A reduction in cardiac output results in: Increased heart rate & may cause a
decrease in BP
BP & deterioration
An increase or decrease in SBP by 20% from normal indicates significant change.
Decreased BP is a late sign of deterioration. BP critical to support O2 and nutrient
supply, organs are dependent on adequate pressure to ensure perfusion (SBP
+100mmHg)
Seagull sign
indicates a decrease in cardiac output and failing compensation mechanisms.
o When there is a drop in stroke volume the heart rate will increase to maintain an
adequate cardiac output.
o If no intervention the increasing heart rate will eventually reduce stroke volume,
this decreases cardiac output and therefore blood pressure -a sign that
compensation mechanisms are failing
Pulse pressure
The difference between systolic blood pressure and diastolic blood pressure.
o Narrows pulse pressure as a last-ditch effort to compensate.
Low pulse pressure
indicates insufficient preload, heart failure, shock state.
Wide pulse pressure
numerous causes: atherosclerosis, hyperthyroidism, raised ICP
hypovolemic shock
Inadequate circulating volume due to blood and /or fluid loss
hypovolemic shock causes
sustained vomiting/ diarrhoea, severe dehydration, surgery, fluid shifts i.e third
spacing (burns, ascites), haemorrhage
Result of hypovolemic shock
o Decrease in venous return to the right side of the heart (decreased preload)
o Decreased stroke volume
o Decreased cardiac output
o Decreased oxygenation
o Resulting in impaired tissue perfusion and cellular metabolism