Indirect Calorimetry For The Assessment Of Energy Metabolism In Critically Ill Patients

Objective: To determine and assess the resting energy expenditure on critically illnesswith mechanical ventilation by indirect calorimetry. To discuss the affecting factors on theresting energy expenditure of critically illness and correlations among relevant indicators.Methods: Choose the mechanical ventilated patients in the General Hospital of NingxiaMedical University Comprehensive ICU and Synthesized ICU of Cardiovascular Hospital inAugust2012, September2012and January2014to assess the APACHE Ⅱand the NRS2002.Then measure the resting energy expenditure by indirect calorimetry and compare the resultwith the actual amount of nutrient supply given by clinicians according to the patient’s actualconditions. In terms or the result, we divide the patients into two groups according to thecourse of different stages, critical to varying degrees, and presence of systemic inflammatoryresponse (SIRS). Then divide them into four groups on the basis of the loss degree ofenergy. Compare the APACHE Ⅱscore, duration of hospitalization and mortality among fourgroups. At last analyze the relationship between patients’ general information, biochemicalindexes and the resting energy expenditure in multiple regression method.Result:Participants included60patients with severe.（1）In severe cases the actualnutrition supply level significantly（pREE,1474.3±488.9kcal/d） lower than the indirectmethod of measuring thermal measurement resting energy expenditure(mREE,1790.2±377.6kcal/d),(P<0.05);(2)The different stages of disease, the group of patients withthe acute phase of pREE (1258.8±558.4kcal/d) clearly lower than the mREE (1796.1±398.5kcal/d), there was a significant difference in statistical significance (p <0.001); Therewas no statistically significant difference between the two group patients in the steadyperiod;(3)The APACHE II score≥15group (1366.1±550.9VS1785.6±373.7kcal/d)、 APACHE II score <15group (1590.1±389.5VS1795.1±388.2kcal/d)、 SIRS group(1430.1±434.1VS1892.1±383.5kcal/d)、non SIRS group REE (1522.7±348.3VS1706.8±356.9kcal/d), each group of patients with pREE below mREE, the difference wasstatistically significant (P <0.05).(4) Energy deficit more serious group average APACHEⅡ score higher、ICU extension of such confinement,28d increase mortality，Compared withrelative energy balance group, statistical differences were very significant (P <0.01)；(5) Themultiple regression analysis showed that heart rate, body weight, body temperatureassociation with resting energy expenditure. Age, APACHE II score, blood pressure,respiratory frequency and respiratory quotient index has no relevance.Conclusion：(1) Patients with s energy deficit in the heavier the illness and SIRSconditions，increase significantly difference, and the hospitalization time relatively longer,higher mortality;（2）The nutrition supply given by clinicians was significantly lower thanthe REE measured by indirect calorimetry, particularly patients. in acute;(3) Bedsideimmediate indirect energy measurement is a good guide for adjustment of clinical nutrition.