Long chain versus medium chain lipids in patients with ARDS: effects on pulmonary haemodynamics and gas exchange.
OBJECTIVE
To compare pulmonary haemodynamic and gas exchange alterations in septic patients with ARDS receiving long-chain triglycerides (LCT) versus medium-chain triglycerides (MCT).


METHODS
Prospective, randomised, clinical study.


METHODS
Surgical ICU patients in a University Hospital.


METHODS
Twenty-one septic patients with ARDS were randomly assigned to receive 50 % of their non-protein caloric requirements as either 20 % LCT (group 1, n = 10) or 20% 1:1 mixture of LCT/MCT (group 2, n = 11).


METHODS
Intravenous infusion of LCT and LCT/MCT combinations at a rate of 12 g x h(-1).


RESULTS
The LCT infusion was associated with an increase of pulmonary venous admixture (Qva/Qt) from 24 % +/- 5 % to 37 % +/- 6 %, an increase of mean pulmonary artery pressure (MPAP) from 25 +/- 5 to 33 +/- 4 mmHg and decrease of PaO2/FIO2 from 240 +/- 30 to 180 +/- 35. LCT/MCT administration was only associated with an elevation of oxygen consumption (VO2) from 329 +/- 14 to 396 +/- 12 ml/ min. During lipid infusion group 1 patients presented higher Qva/Qt (37% +/- 6% vs 25% +/- 4%), MPAP (33 +/- 4 vs 27 +/- 3 mmHg) and VO2 (359 +/- 11 vs 396 +/- 12 ml/min) and lower PaO2/FIO2 (180 +/- 35 vs 235 +/- 30) values compared to group 2.


CONCLUSIONS
In conclusion, we have shown that, in septic patients with respiratory failure, LCT administration was associated with more significant changes of Qva/Qt, MPAP and PaO2/FIO2 compared to infusion of an LCT/MCT 1:1 emulsion. Clinically, these transient alterations might cause serious problems in patients with marginal arterial oxygenation and cardio-respiratory impairment.
Smirniotis
V
V
2nd Department of Surgery, University of Athens Medical School, Areteion Hospital, Greece. narkado@otenet.gr
Kostopanagiotou
G
G
Vassiliou
J
J
Arkadopoulos
N
N
Vassiliou
P
P
Datsis
A
A
Kourias
E
E
D000328:Adult; D000368:Aged; D001784:Blood Gas Analysis; D002149:Energy Intake; D005217:Fat Emulsions, Intravenous / Q000737:chemistry / Q000627:therapeutic use*; D005260:Female; D006439:Hemodynamics / Q000187:drug effects*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009751:Nutritional Requirements; D010101:Oxygen Consumption / Q000187:drug effects; D011446:Prospective Studies; D011652:Pulmonary Circulation / Q000187:drug effects*; D011659:Pulmonary Gas Exchange / Q000187:drug effects*; D011669:Pulmonary Wedge Pressure / Q000187:drug effects; D012128:Respiratory Distress Syndrome / Q000188:drug therapy* / Q000378:metabolism / Q000382:microbiology / Q000503:physiopathology; D018805:Sepsis / Q000150:complications; D014280:Triglycerides / Q000737:chemistry / Q000627:therapeutic use*
D005217:Fat Emulsions, Intravenous; D014280:Triglycerides