Long term lipid-based parenteral nutrition causes pulmonary hypertension in pigs

Abstract

Objective: To study pulmonary perfusion after long term intravenous lipid-based total parenteral nutrition (TPN).

Design: Open experimental study.

Setting: Teaching hospital, Norway.

Material: 31 pigs.

Interventions: Infusion of TPN alone, TPN + pellets, or Ringer's solution alone through central venous catheters for 7 weeks.

Outcome measures: Haemodynamic variables during a standardised volume load, and measurement of plasma N-terminal pro-atrial natriuretic factor (ANF).

Results: Mean pulmonary artery pressure (PAP) was 12.9 (6.1) to 20.1 (3.0) mmHg in response to the volume load in control animals compared with 15.8 (8.5) to 25.4 (5.8) (p < 0.05) mmHg in those given TPN alone and 22.8 (10.3) (p < 0.05) to 28.0 (6.4) (p < 0.05) mmHg in those given TPN and pellets. Pulmonary vascular resistance index was also increased after TPN, but the plasma N-terminal pro-ANF concentration did not increase during infusion of TPN.

Conclusion: Long term TPN caused moderate pulmonary hypertension, but not longstanding right-sided congestion.