EFFECTIVENESS OF CHEST TUBE CLAMPING IN MASSIVE HEMOTHORAX

Objective: To test the effectiveness of chest tube clamping in massive hemothorax. Design, Materials and Methods: This was assessed in 32 sp ontaneously breathing Yorkshire piglets with 2.5 mm (groups A and B) o r 4.0 mm (groups C and D) lacerations of the thoracic aorta. Measureme nts: Hemodynamics, blood loss, length of survival, and arterial blood gases (on 100% oxygen) were monitored. The four groups of eight animal s all had chest tubes but groups A and C had these tubes clamped. Meas urements were made at baseline, immediately after aortic injury, and e very 15 minutes until death. Results: Groups C and D survived 39 +/- 4 and 38 +/- 5 minutes respectively compared to 68 +/- 6 and 70 +/- 4 m inutes in groups A and B. Total blood loss was not statistically signi ficantly different among the four groups (1225 +/- 72, 1312 +/- 84, 10 20 +/- 90, and 1110 +/- 84 mt for groups A, B, C, and D respectively). The rate of blood loss was greater in groups C and D (29.4 +/- 0.2 mt and 30.1 +/- 0.3 mL/min) compared with 14.7 +/- 0.5 mt and 16.0 +/- 0 .9 mL/min respectively in groups A and B. Blood loss rate was similar with clamped or unclamped chest tubes. Ah groups had similar baseline cardiac output (3.5 to 3.8 L/min) and arterial blood pressures (110 to 114 mm Hg) with a greater decrease in these parameters following the larger lacerations and no difference with chest tube clamping. Arteria l Po, decreased from approximately 400 to 50 mm Hg with clamping but o nly decreased to approximately 350 mm Hg without clamping. The hypoxia was associated with significant hypercapnea (Pco(2) of 78 mm Hg). Con clusions: Chest tube clamping did not decrease hemorrhage or mortality but worsened gas exchange without improving hypotension and is theref ore not recommended in the treatment of massive hemothorax,