Re. Drake et al., INTESTINAL LYMPHATIC PRESSURE INCREASES DURING INTRAVENOUS INFUSIONS IN AWAKE SHEEP, The American journal of physiology, 265(3), 1993, pp. 180000703-180000705
Intravenous fluid infusions cause increased venous pressure and increa
sed lymph flow throughout the body. Together the increased lymph flow
and increased venous pressure (the outflow pressure to the lymphatic s
ystem) should increase the pressure within the postnodal intestinal ly
mphatics. To test this, we measured the pressure in postnodal intestin
al lymphatics and the neck vein pressure in five awake sheep. At basel
ine, the neck vein pressure was 1.2 +/- 1.5 (SD) cmH2O and the lymphat
ic pressure was 12.5 +/- 1.7 cmH2O. When we infused Ringer solution in
travenously (10% body weight in approximately 50 min), the neck vein p
ressure increased to 17.3 +/- 0.9 cmH2O and the lymphatic pressure inc
reased to 24.6 +/- 3.8 cmH2O (both P < 0.05). In two additional sheep,
the thoracic duct lymph flow rate increased from 0.8 +/-0.4 ml/min at
baseline to 5.5 +/- 2.0 ml/min during the infusions. Our results show
that postnodal intestinal lymphatic pressure may increase substantial
ly during intravenous fluid infusions. This is important because incre
ases in postnodal lymphatic pressure may slow lymph flow from the inte
stine.