Importance of low blood-pH
To the Editor of British Medical Journal
In the „Case Report“ (1) are four questions concerning the reported
patient and later are „short“ and „long“ answers to these questions.
In the answers, one important issue has been omitted: on arrival, the
patient was „disoriented, and confused“. The immediate cause of this
decreased level of consciousness with potentially further deterioration to
fatal coma is the very low blood pH of 6.72. According to Edge et al(2)
with decreasing blood pH is decreasing also the level of consciousness:
with blood pH around 7.10 are the patients drowsy, around 6.06
semiconscious or confused and around 6.88 comatose. The glycolytic enzyme
phosphofructokinase is pH dependent, as its activity is decreasing with
decreasing pH, and, thus, glucose utilization in brain cells is impaired
(3). Therefore, the clinical consequences of decreasing blood pH are as
reported by Edge et al (2). The lactate anion per se is harmless:
infusions of Ringer-lactate solution are used worldwide without reports on
Therefore, in the reported patient, immediately life saving was the
increase of blood pH of 6.72 to values around 7.30 achieved within 8
Dr. Viktor Rosival,
SYNLAB Department of Laboratory Medicine, Dérer s Hospital,
Limbová 5, SK-833 05 Bratislava,Slovakia.
1. Lemyze M, Baudry JF, Collet F, Guinard N. Life threatening lactic
acidosis. BMJ 2010;340:c857.
2. Edge JA, Roy Y, Bergomi A, Murphy NP, Ford-Adams ME, Ong KK,
Dunger DB. Conscious level in children with diabetic ketoacidosis is
related to severity of acidosis and not to blood glucosd concentration.
Pediatr Diabetes 2006;7:11-5.
3. Trivedi B, Danforth WH. Effect of pH on the Kinetics of Frog
Muscle Phosphofructokinase. J biol Chem 1966;241:4110-2.
Competing interests: No competing interests