Am. J. Respir. Crit. Care Med.,
Volume 161, Number 4, April 2000, 1149-1153
The Treatment of Acidosis in Acute Lung Injury with
Tris-Hydroxymethyl Aminomethane (THAM)
RICHARD H.
KALLET,
ROBERT M.
JASMER,
JOHN M.
LUCE,
LUDWIG H.
LIN,
and
JAMES D.
MARKS
Department of Anesthesia and Division of Pulmonary and Critical Care Medicine, University of California, San Francisco at
San Francisco General Hospital, San Francisco, California
Mechanical hyperventilation of acidemic patients with acute lung
injury (ALI) requires the use of high volumes and pressures that
may worsen lung injury. However, permissive hypercapnia in the
presence of shock, metabolic acidosis, and multi-organ system dysfunction may compromise normal cellular function. Tris-hydroxymethyl aminomethane (THAM) may be an effective method
to control acidosis in this circumstance. Protonated THAM is excreted by the kidneys, so that carbon dioxide production is not
raised. In an uncontrolled study, we administered THAM to 10 patients with acidosis (mean pH = 7.14) and ALI (mean lung injury
score = 3.28) in whom adequate control of arterial pH could not
be maintained during either eucapnic ventilation or permissive hypercapnia ventilation. THAM was given at a mean dose of 0.55 mmol/kg/h. Administration of THAM was associated with significant improvements in arterial pH and base deficit, and a decrease
in arterial carbon dioxide tension that could not be fully accounted for by ventilation. Although further studies are needed to
confirm these observations, THAM appears to be an effective alternative to sodium bicarbonate for treating acidosis during ALI.