Letters to the Editor: Letters & Announcements
To the Editor:
We read with interest the article by Braz et al. (1) on hypertonic saline and its effects on systemic and gastrointestinal oxygenation in a model of hemorrhagic shock and wish to commend the authors on the quality of their work. Perhaps not surprisingly, although improving oxygenation, hypertonic saline resuscitation resulted in a significantly lower arterial pH than did other resuscitation fluids. A hypertonic extracellular environment impacts upon cytoskeletal dynamics, causing cellular shrinkage with extravasation of osmotic water, accompanied by alterations in protein kinase phosphorylation, gene translation, and second messenger cascades (2,3). The resultant changes in transmembrane potential and cytosolic ion composition impact significantly upon natriferic transport, which influences local pH and metabolism (4,5).
In addition to intravascular volume expansion by interstitial fluid mobilization, the benefits of transient hyperosmolar resuscitation include direct myocardial stimulation (6), reduced flow viscosity with peripheral arterial dilation (7), and end-organ protection (8,9). Added to this are the findings of Braz et al. (1) on gut and systemic oxygenation. These characteristics of hypertonic saline render it a unique resuscitation agent that has the potential to attenuate organ injury in systemic inflammatory and shocked states.
C. J. Shields, MD
D. C. Winter, MD
St. Vincent’s University Hospital
Dublin 4, Ireland
1. Braz JR, do Nascimento P Jr, Paiva Filho O, et al. The early systemic and gastrointestinal oxygenation effects of hemorrhagic shock resuscitation with hypertonic saline and hypertonic saline 6% dextran-70: A comparative study in dogs. Anesth Analg 2004;99:536–46.
2. Denham W, Yang J, Wang H, et al. Inhibition of p38 mitogen activate kinase attenuates the severity of pancreatitis-induced adult respiratory distress syndrome. Crit Care Med 2000;28:2567–72.
3. Fulkerson WJ, MacIntyre N, Stamler J, et al. Pathogenesis and treatment of the adult respiratory distress syndrome. Arch Intern Med 1996;156:29–38.
4. Winter DC, O’Sullivan GC, Harvey BJ, Geibel JP. Direct effects of dopamine on colonic mucosal pH - implications for tonometry. J Surg Res 1999;83:62–8.
5. Winter DC, Schneider MF, O’Sullivan GC, et al. Rapid effects of aldosterone on sodium-hydrogen exchange in isolated colonic crypts. J Membr Biol 1999;170:17–26.
6. Kramer GC, Perron PR, Lindsey DC, et al. Small-volume resuscitation with hypertonic saline dextran solution. Surgery 1986;100:239–47.
7. Mazzoni MC, Borgstrom P, Intaglietta M, et al. Capillary narrowing in hemorrhagic shock is rectified by hyperosmotic saline-dextran reinfusion. Circ Shock 1990;31:407–18.
8. Shields CJ, Winter DC, Sookhai S, et al. Hypertonic saline attenuates end-organ damage in an experimental model of acute pancreatitis. Br J Surg 2000;87:1336–40.
9. Shields CJ, Winter DC, Manning BJ, et al. Hypertonic saline infusion for pulmonary injury due to ischemia-reperfusion. Arch Surg 2003;138:9–14.