28. THE CHILD WITH CIRCULATORY PROBLEMS Jamie Ranse : Critical Care Education Coordinator, Staff Development Unit, ACT Health.
Notas do Editor
The total circulating volume of a 1 year old is roughly the same as the amount of water you pour on your indoor pot plant. At about 80mls/kg it doesn’t take much loss before you have a significantly shocked baby on your hands. With circulatory function failing, oxygen and nutrients are not reaching the cells and cellular waste products are not being cleared. Circulatory assessment is therefore a very important skill to develop in order to recognise the early signs of a shocked child. heart rate: Increased heart rate may indicate shock, or hypoxia. or fever, or anxiety. Bradycardia is defined as a heart rate less than 60 or a rapidly falling heart rate with poor systemic perfusion. Bad, bad, bad. Cardiac compressions will need to be commenced in infants with HR<60 and poor perfusion. You will probably be experiencing a holy crap moment at this time and be hesitant to begin CPR. If in doubt, just do it. *Unnecessary* chest compressions are almost never damaging. pulse volume and blood pressure: A good indicator of general perfusion can be made by palpating peripheral and central pulses. A poor central pulse with absent peripheral pulses is a sign of significant shock. Remember: when fitting a blood pressure cuff to a childs arm it is vital to select the correct cuff size. The width of the cuff should cover no less than 80% the length of the upper arm. The child’s blood pressure is a much less sensitive indicator, as it may remain *compensated* until circulatory collapse is imminent. You can estimate the expected systolic blood pressure with the following formula: BP= 80+(age in years * 2) . A very low BP is a warning of imminent cardiac arrest, get busy! capillary refill: A slow capillary refill time indicates poor skin perfusion. Press down firmly with your finger on the sternum for 5 seconds and release. ( alternatively you can use the nail bed or soles of the feet.) A normal capillary refill should occur within 2-3 seconds. Capillary refill time is not a useful indicator in the hypothermic patient. Other effects: Decreased perfusion will lead to an inability of the cells to *take out the trash*. The resulting metabolic acidosis will result in an increased respiratory rate and tidal volumes (without other signs of respiratory distress such as recession) as the lungs try and blow off carbonic acid. The skin may appear mottled or marbled and cold to touch. Decreased level of consciousness. Drowsiness and/or agitation may increase as cellular perfusion decreases. The most sensitive indicator of changes in mental state is of course the parents. Decreased urine output due to decreased perfusion of the kidneys. Less than 2ml/kg/hour in infants and 1 ml/kg/hour in children is a red flag. Once again ask the parents for any history of decreased output. As babies and infants develop significant circulatory compromise it is not exactly rocket science to pick that they are sick. As they begin to die they begin to look dead. But the sensitivity to pick up on early signs of shock is more of an art, and will make a big difference in outcome. Here is a pretty good summation from the Emergency Medicine Journal for you to print out and leave in the toilet for reading. What… you don’t do your best study in the toilet?
HR dependent, Tachycardia is the earliest clinical manifestation in compensated shock, but is also may be a result of pain, anxiety, etc… If other signs of compensated shock (decreased Cap refil, cool, mottling skin, decreased peripheral pulses, narrowing pulse pressure, tachyponea)
Circulating volume ~80ml/kg in children v ~70ml/kg in adults little loss = big effect Begin fluid resuscitation early, Mild hyotension should be treated early
Due to small anatomy, IO insertion threshold is lower in children then in adults
Myocardium – HR dependent Body water - GIT proportionally longer therefore greater losses, Metabolic rate greater - greater metabolic wastes therefore greater need for water for excretion BSA - greater therefore greater insensible loss - infant 2 - 3 times greater than adult - - greater heat production and therefore water loss Fluid requirements - greater proportion of ECF exchanged daily in infants than older children because of the above needs for water. This leaves the infant with little reserve in dehydration Renal function - difficulty in concentrating or diluting urine - conserving or excreting Na and acidifying urine - therefore more prone to dehydration or over hydration
Pulse characteristics (peripheral rate v heart rate) Cap refil central v peripheral
Steiner Systematic review – small number of studies Clinical assessment is best Prolonged capillary refill time, abnormal skin turgor, and abnormal respiratory pattern are the most useful signs for detecting dehydration in children. Combinations of signs perform better than individual signs. RCH protocol Clinical findings Mild <4% - no clinical signs Moderate 4-6% Some physical signs Severe >7% multiple physical signs – may also have acidosis and hypotension
Skin and respiratory systems – children have higher insensible losses then adults
Anatomy and physiology of water electrolyte balance in infants - factor effecting fluid requirements recognizing the seriously ill child structured approach to the seriously ill child resuscitation of infant assessment of cardiovascular system and fluid status management of fluid and electrolyte imbalance - potassium why is the infant so prone to dehydration normal vital signs - BP IV access or IO appropriate IV fluids equipment for infant and child psychosocial needs of an infant and family causes of diarrhoea in infants management of diarrhoea - nutrition infection control investigations - initial and ongoing possible complications - cerebral oedema history
The total circulating volume of a 1 year old is roughly the same as the amount of water you pour on your indoor pot plant. At about 80mls/kg it doesn’t take much loss before you have a significantly shocked baby on your hands. With circulatory function failing, oxygen and nutrients are not reaching the cells and cellular waste products are not being cleared. Circulatory assessment is therefore a very important skill to develop in order to recognise the early signs of a shocked child. heart rate: Increased heart rate may indicate shock, or hypoxia. or fever, or anxiety. Bradycardia is defined as a heart rate less than 60 or a rapidly falling heart rate with poor systemic perfusion. Bad, bad, bad. Cardiac compressions will need to be commenced in infants with HR<60 and poor perfusion. You will probably be experiencing a holy crap moment at this time and be hesitant to begin CPR. If in doubt, just do it. *Unnecessary* chest compressions are almost never damaging. pulse volume and blood pressure: A good indicator of general perfusion can be made by palpating peripheral and central pulses. A poor central pulse with absent peripheral pulses is a sign of significant shock. Remember: when fitting a blood pressure cuff to a childs arm it is vital to select the correct cuff size. The width of the cuff should cover no less than 80% the length of the upper arm. The child’s blood pressure is a much less sensitive indicator, as it may remain *compensated* until circulatory collapse is imminent. You can estimate the expected systolic blood pressure with the following formula: BP= 80+(age in years * 2) . A very low BP is a warning of imminent cardiac arrest, get busy! capillary refill: A slow capillary refill time indicates poor skin perfusion. Press down firmly with your finger on the sternum for 5 seconds and release. ( alternatively you can use the nail bed or soles of the feet.) A normal capillary refill should occur within 2-3 seconds. Capillary refill time is not a useful indicator in the hypothermic patient. Other effects: Decreased perfusion will lead to an inability of the cells to *take out the trash*. The resulting metabolic acidosis will result in an increased respiratory rate and tidal volumes (without other signs of respiratory distress such as recession) as the lungs try and blow off carbonic acid. The skin may appear mottled or marbled and cold to touch. Decreased level of consciousness. Drowsiness and/or agitation may increase as cellular perfusion decreases. The most sensitive indicator of changes in mental state is of course the parents. Decreased urine output due to decreased perfusion of the kidneys. Less than 2ml/kg/hour in infants and 1 ml/kg/hour in children is a red flag. Once again ask the parents for any history of decreased output. As babies and infants develop significant circulatory compromise it is not exactly rocket science to pick that they are sick. As they begin to die they begin to look dead. But the sensitivity to pick up on early signs of shock is more of an art, and will make a big difference in outcome. Here is a pretty good summation from the Emergency Medicine Journal for you to print out and leave in the toilet for reading. What… you don’t do your best study in the toilet?