Critical illness in children may have an impact on long-term outcome. Over a three year period (Jan 2010 - December 2012), 57,949 children were admitted across 30 paediatric intensive care units (PICU) in the UK. Although outcomes are improving the number of admissions is increasing.\cite{Network:2013tj} There is a need for research into the most common therapeutic interventions instigated in paediatric intensive care. Supplemental oxygen is one such strategy. Oxygen is usually administered in the setting of hypoxia. Is there enough evidence to support this strategy? \\
In this thesis, I explored the hypothesis that children adapt to hypoxic conditions during critical illness. First, evidence on the effect of hypoxia and hyperoxia on outcome …show more content…
High altitude balloonists were amongst the first to clearly describe the effects of acute hypoxia. These effects were attributed to the low barometric pressure and low partial pressure of oxygen (hypobaric hypoxia).\cite{JohnBWest:2009wj} Barcroft classified hypoxia into 3 sub-categories: anoxic type (hypobaric hypoxia), anaemic type (inability to carry oxygen) and stagnant type (hypoxia secondary to circulatory failure). \cite{West2013} He wrote \\
\enquote{\textit{Anoxaemia not only stops the machine, but wrecks the machinery}}\\
He hypothesised that chronic hypoxia must elicit an acclimatising effect from the human body in the form of an increase in haemoglobin or blood flow.\cite{Barcroft:1920ts} The physiological effects of acute hypoxia, especially when associated with increasing altitude, have been clearly described in the last few decades. Unconsciousness was noted to be a pre-terminal sign of acute severe hypoxia reflecting inadequate brain oxygenation.\cite{Sharp:1978wp} Figure 1.1 describes the impact of worsening hypoxia (due to increasing altitude) on the body. It also shows the rapidity of onset of unconsciousness from about 6000 meters above sea level. Although the effects of acute hypoxia are understood, it has been more difficult to delineate the effects of chronic hypoxic
In this thesis, I explored the hypothesis that children adapt to hypoxic conditions during critical illness. First, evidence on the effect of hypoxia and hyperoxia on outcome …show more content…
High altitude balloonists were amongst the first to clearly describe the effects of acute hypoxia. These effects were attributed to the low barometric pressure and low partial pressure of oxygen (hypobaric hypoxia).\cite{JohnBWest:2009wj} Barcroft classified hypoxia into 3 sub-categories: anoxic type (hypobaric hypoxia), anaemic type (inability to carry oxygen) and stagnant type (hypoxia secondary to circulatory failure). \cite{West2013} He wrote \\
\enquote{\textit{Anoxaemia not only stops the machine, but wrecks the machinery}}\\
He hypothesised that chronic hypoxia must elicit an acclimatising effect from the human body in the form of an increase in haemoglobin or blood flow.\cite{Barcroft:1920ts} The physiological effects of acute hypoxia, especially when associated with increasing altitude, have been clearly described in the last few decades. Unconsciousness was noted to be a pre-terminal sign of acute severe hypoxia reflecting inadequate brain oxygenation.\cite{Sharp:1978wp} Figure 1.1 describes the impact of worsening hypoxia (due to increasing altitude) on the body. It also shows the rapidity of onset of unconsciousness from about 6000 meters above sea level. Although the effects of acute hypoxia are understood, it has been more difficult to delineate the effects of chronic hypoxic