The Prevalence of Iatrogenic Underfeeding in the Nutritionally ‘At-Risk’ Critically ill Patient

Rupinder Dhaliwal, RDExecutive Director

Nutrition & Rehabilitation Investigators ConsortiumClinical Evaluation Research Unit

Queen’s University, Kingston, Canada

IntroductionCritically ill patients receive only 50% prescribed energy and protein needs

This “underfeeding”, considered to be IATROGENIC, could lead toadverse consequences However, not all critically ill patients seemed to be harmed more as a consequence of iatrogenic underfeeding

0200400600800

100012001400160018002000

1 3 5 7 9 11 13 15 17 19 21

Days

kcal

Prescribed Engergy

Energy Received From Enteral Feed

Caloric debt

Who benefits from nutrition therapy in in the ICU?

Multicenter observational study, 2772 patients For every increase of 1000 calories per day

– reduction in overall 60-day mortality (p=0.014) – increase in ventilator-free days (p=0.003)

Beneficial treatment effect of increased calories was only observed in:– BMI<25 and >35 – no benefit in BMI 25-<35 group

NUTrition Risk in the Critically ill Score (NUTRIC Score) severity of the underlying illness the degree of acute markers of inflammation and starvation indices the degree of chronic markers of inflammation and starvation indices

Helps discriminate which ICU patients will benefit more (or less) from aggressive protein-energy provision

NUTRIC score ≥ 6 (out of 10) may benefit the most from nutrition therapy

Mechanically ventilated > 7 daysUnderfeeding in pts mechanically ventilated >7 days WORSE outcomes!

Energy deficit of ~1200 kcals/day is associated with an independent likelihood of ICU death (Faisy et al British J Nutrition 2009)

Recent randomized trials FAIL to show a difference in the group that received the most calories (Casaer et al NEJM 2011, Rice et al Crit Care Med 2011)

Why so? 1. BMI mid ranges2. Patients young, few comorbidities, so low NUTRIC

3. short stays in ICU (<5 days on average)

What is optimal nutrition?

Heyland DK Crit Care Med 2011Analyzed patients who were mechanically ventilated and in the ICU for 96 hrs or >

Receiving up to 80% of their prescribed energy requirements is associated with a reduced mortality (>80-85% no added effect)

We posit that nutritionally ‘at-risk’ pts should receive at least 80% prescribed needs

Focus on patients that stayed in the ICU ≥ 96 hrs

Objective• describe the prevalence of “Iatrogenic Underfeeding”

(receiving < 80% prescribed energy and protein) in ICUs across different Geographic areas

• in ‘high risk’ patients subgroups– (those with > 7 days of mechanical ventilation)– body mass index (BMI) of <25 and >35 – those with a NUTRIC score of >6 compared to low risk patients

• to determine those ICU and hospital characteristics associated with optimal nutrition practice (lowest rates of iatrogenic underfeeding)

Methods

Analysis of data from

May 11, 2011 prospective, multi-institutional audit 193 ICUs in 29 countries collected data ~20 pts per ICU, ICU LOS at least 96 hrs 3174 mechanically ventilated patients

Geographical regions

Sites were divided approximately by continent – Canada, US separate as many ICUs

Sites from countries or continents with too few sites to comprise a unique region were compared to similar region of practice• Mexico & South Africa

Data CollectionFor each patient patient characteristics and ICU admission information baseline nutrition assessment

method of calculation (e.g. indirect calorimetry, predictive equations) total calories and protein prescribed

daily nutrition data for first 12 days or IC d/c whatever first Route i.e. EN or PN total calories and protein prescribed

patient outcomes ICU and hospital discharge and mortality. Duration of mechanical ventilation

web-based electronic data capture system

Statistical Approach• adequacy of total nutrition during the first 12 days in ICU

% percent of caloric and protein prescriptions received from EN or PN• SOFA score and IL-6 was dropped from the original NUTRIC

score • high vs. Low NUTRIC: according to median NUTRIC Score (i.e. patients

with NUTRIC > median were classified as high risk subgroup) • multivariable analysis was performed

– to examine the association between the prevalence of iatrogenic underfeeding – repeated using three different sets of adjustments to account for

• # days in evaluation (first few days patients receive < 80%)• added covariates (ICU characteristics and patient characteristics)• simultaneously included high risk factors in addition to all covariates used

Results

Canada: 20 (20%)

USA: 45 (23%)

Australia & New Zealand: 39 (20%)

Europe and South Africa: 25 (13%)

Latin America: 24 (12%)

Asia: 41 (21%)

n = 193 ICUs, 29 countries, 3174 patients

ICU CharacteristicsCharacteristics Total (n=193)

Hospital Type

Teaching 149 (77.2%)Non-teaching 44 (22.8%)

Size of Hospital (beds) Mean (Range) 633 [100- 2600]

ICU Structure Open 49 (25.4%)

Closed 140 (72.5%)Other 4 (2.1%)

Size of ICU (beds) Mean (Range) 17.7 [5 - 65]

Designated Medical Director 182 (94.3%)Presence of Dietitian(s) 153 (79.3%)FTE Dietitians (per 10 beds)

Mean (Range) 0.4 [0 -3.3]

Total used in analysis

3174 patients from 193 ICUs

29 countries

2011 International Nutrition Survey

3747 patients from 193 ICUs

29 countries

573 Excluded from analysis

378 in ICU <96 hours 195 nutritional adequacy not available for at least 4 days

 1812 patients > 7 days of mechanical ventilation

 350 patients

with BMI ≥ 35

 1533 patients

with BMI <25

 1013 patients

with NUTRIC > 4

Results Patient Flow Diagram

Patient Characteristics

Total Canada Australia and NZ USA Europe and

South AfricaLatin

America Asia p values†

N 3174 361 602 670 416 442 683Age (years)

mean (SD) 60.3(17.8) 64.6(16.0) 58.2(17.8) 61.5(17.2) 58.8(17.1) 56.7(19.4) 62.0(17.7) <0.001

SexMale (%) 1884

(59.4%) 191 (52.9%) 365 (60.6%) 353 (52.7%) 260 (62.5%) 257 (58.1%) 458 (67.1%) <0.001

Admission Medical

2031 (64.0%) 260 (72.0%) 370 (61.5%) 474 (70.7%) 224 (53.8%) 284 (64.3%) 419 (61.3%) 0.01

Elective surgery 361 (11.4%) 35 (9.7%) 74 (12.3%) 53 (7.9%) 56 (13.5%) 28 (6.3%) 115 (16.8%)

Emergent surgery 782 (24.6%) 66 (18.3%) 158 (26.2%) 143 (21.3%) 136 (32.7%) 130 (29.4%) 149 (21.8%)

Weight (kg) mean (SD) 76.3(24.5) 78.2(24.2) 81.1(25.2) 86.3(31.9) 77.9( 20.2) 71.3(16.3) 63.6(14.4) < 0.001

BMI mean (SD) 26.9(7.5) 27.8(7.6) 27.9(7.7) 29.8(9.9) 26.8(6.5) 25.9(5.1) 23.7(4.7) < 0.001

APACHE IImean (SD) 21.9(7.7) 23.7(7.1) 22.2(7.9) 22.4(7.4) 21.5(8.2) 19.9(7.1) 21.9(7.7) 0.06

NUTRIC >4

161 (44.6%) 173 (28.7%) 230 (34.3%) 139 (33.4%) 107 (24.2%) 203 (29.7%) 0.002NUTRIC <=4

200 (55.4%) 429 (71.3%) 440 (65.7%) 277 (66.6%) 335 (75.8%) 480 (70.3%)

Nutrition Outcomes (all patients)Total Canada Australia

and NZ USAEurope and

South Africa

Latin America Asia

p values†

N 3174 361 602 670 416 442 683

Prescribed kcal/kg/day Mean (SD) 24.1(5.5) 23.3 (5.3) 25.5(5) 21.5 (6.2) 24.6(5) 24. 5(4.6) 25.4 (5.2) <0.001

Adequacy of calories % Mean (SD) 56 (30.6 ) 63.4(27.3 ) 59.5(27.7 ) 47.8(27.2 ) 54.4(30.3 ) 53.4(27.9 ) 59.8(37.2 ) <0.001

Adequacy of protein % Mean (SD) 51.5(29.2 ) 59.7(27.2 ) 53.9(27.3 ) 44.1(27.0 ) 49.5(29.6 ) 51.1(28.1 ) 53.9(32.7 ) <0.001

Prevalence of iatrogenic underfeeding 2467 (77.7%) 255 (70.6%) 450 (74.8%) 599 (89.4%) 309 (74.3%) 372 (84.2%) 482 (70.6%) <0.001

Time to initiate EN from ICU admission in hours

Mean (SD) 41.7 (43.6) 37.0 (42.8) 32.6 (39.9) 52.3 (43.8) 39.5 (41.7) 48.6 (42.3) 39.2 (46.4) <0.001

78% of patients failed to meet ≥ 80% of energy

target

Nutrition Outcomes: vented > 7 days

Total MV

>7 days <7days

Nutritional adequacy % mean (SD)

Adequacy of calories 56(30.6 )

62.8 (29.0)**

47.1 (30.5)

Adequacy of protein 51.5(29.2 )

58.0 (27.7)**

42.9 (29.1)

Time to initiate EN from ICU admission in hours

Mean (SD) 41.7 (43.6 )

44.1 (46.9 )**

38.3 (38.0)

Prevalence of iatrogenic underfeeding

N (%) 2467 (77.7%)

1295 (71.5%)**

1172 (86.1%)

> 7 d mechanical ventilation

Better calorie adequacy

Better protein adequacy

Longer to start EN

Lower prevalence underfeeding

(all values p<0.01)

BMI ≥ 35 vs. 25-34

Better calorie adequacy (p 0.01-0.05)

No difference

No difference

No difference

Nutrition Outcomes (BMI)

Total BMI

<25 25-34 ≥35Nutritional adequacy % mean (SD)

Adequacy of calories 56(30.6 )

57.8 (32.4)**

54.0 (28.7)

55.6 (29.6)*

Adequacy of protein 51.5(29.2 )

53.5 (30.2)**

50.1 (28.3)

47.9 (27.7)

Time to initiate EN from ICU admission in hours

Mean (SD) 41.7 (43.6 )

38.6 (41.0 )**

44.8 (45.6)

44.4 (46.2)

Prevalence of iatrogenic underfeeding

N (%) 2467 (77.7%)

1136 (74.1%)**

1058 (82.0%)

273 (78.0%)

BMI < 25 vs. 25-34

Better calorie adequacy

Better protein adequacy

Shorter time to EN

Lower prevalence underfeedingall values p<0.01

Nutrition Outcomes (NUTRIC score)

Total NUTRIC score

>4 <4

Nutritional adequacy % mean (SD)

Adequacy of calories 56(30.6 )

55.3 (29.8)

56.4 (31.0)

Adequacy of protein 51.5(29.2 )

51.3 (29.1)

51.2 (29.3)

Time to initiate EN from ICU admission in hours

Mean (SD) 41.7 (43.6 )

43.6 (45.0)

40.8 (42.9)

Prevalence of iatrogenic underfeeding

N (%) 2467 (77.7%)

788 (77.8%)

1679 (77.7%)

NUTRIC Score > 4

No difference

No difference

No difference

No difference

 

Adjusting for number of days included in nutrition

assessment

Adjusting for all covariates* but not other risk factors of

interest

Adjusting for all covariates* and other risk

factors of interest.

Risk Factors of Interest OR (95% CI) p-value OR (95% CI) p-value OR (95% CI) p-value

MV> 7 days (vs. MV ≤ 7 days) 0.67 (0.50-0.90) 0.0077 0.69 (0.51-0.93) 0.0160.68

(0.51-0.92) 0.013

BMI < 25 (vs. BMI between 25 and 35) 0.65 (0.54-0.80) <0.0001 0.67 (0.54-0.83) 0.0002

0.66 (0.54-0.82) 0.0001

BMI > 35 (vs. BMI between 25 and 35) 0.64 (0.49-0.84) 0.0014 0.64 (0.47-0.86) 0.0036

0.64 (0.47-0.86) 0.0038

NUTRIC > 4 (vs. NUTRIC ≤ 4) 1.06 (0.88-1.27) 0.55 1.02 (0.78-1.35) 0.861.04

(0.79-1.38) 0.75

Multivariate analysis (odds of receiving <80% of prescription)

being mechanically ventilated for more than 7 dayshaving a BMI <25 and having a BMI ≥35 were all associated with about a one third reduction in the odds of receiving <80% of energy prescription

Conclusions

Worldwide, the majority of critically ill patients fail to receive adequate nutritional intake

This rate of failure varies across geographic regions

High risk patients are less likely to be underfed than low risk patients but still experience significant underfeeding

AcknowledgementsDaren K. Heyland MD, MSc Lauren Murch MScXuran Jiang MSc Andrew G. Day MSc

Clinical Evaluation Research Unit, Kingston General HospitalDepartment of Community Health and Epidemiology, Queen’s UniversityDepartment of Medicine, Queen’s UniversityKingston, ON, Canada

References

• Alberda C, Gramlich L, Jones NE, Jeejeebhoy K, Day A, Dhaliwal R, Heyland DK. The relationship between nutritional intake and clinical outcomes in critically ill patients: Results of an international multicenter observation study. Intensive Care Med 2009;35(10):1728-37.

• Faisy C, Lerolle N, Dachraoui F, Savard JF, About I, Tadie JM, Fagon JY. Impact of energy deficit calculated by a predictive method on outcome in medical patients requiring prolonged acute mechanical ventilation. British J Nutrition 2009;101:1079-1087.

• Heyland DK, Dhaliwal R, Jiang X, Day A. Quantifying nutrition risk in the critically ill patient: The development and initial validation of a novel risk assessment tool. Critical Care 2011

• Casaer MP, Mesotten D, Hermans G, et al. Early versus late parenteral nutrition in critically ill adults. N Engl J Med 2011;June 29 (epub).

• Rice T, Morgan S, Hays MA, Bernard GR, Jensen GL, Wheeler AP. Randomized trial of initial trophic versus full-energy nutrition in mechanically ventilated patients with acute respiratory failure. Crit Care Med 2011;39;967-974.

• Heyland DK, Cahill N, Day A. Optimal amount of calories for critically ill patients: Depends on how you slice the cake! Crit Care Med 2011 Jun 23 (epub).

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