Objective

Key Points

• Not all obese patients are the same

• Nutritional approach may need to vary

• Challenge to the prevailing dogma that hypocaloric feeding (undernourishment) is acceptable

2000

Obesity Trends* Among U.S. AdultsBRFSS, 1990, 2000, 2010

(*BMI 30, or about 30 lbs. overweight for 5’4” person)

2010

1990

No Data <10% 10%–14% 15%–19% 20%–24% 25%–29% ≥30%

Relative Trends

Sturm, Pub Health, 2007, 121:492 (BRFSS data)

What to do when the obese patient becomes

critically ill?

Feeding the Obese Critically Ill (BMI>30)

• Provide 50-70% of target energy requirements (>14 kcal/kg actual body weight) and >2.0-2.5 g/kg IBW/d protein)*

Americans

• Insufficient evidenceCanadians

• (silent)

Europeans

*Choban JPEN 2013

Burge JPEN 1994

RCTs of Hypocaloric Nutrition in Obesity (1)

• 16 hospitalized obese patients requiring PN (? ICU, ‘mild-moderate stress’)

• Defined obesity as >130% IBW• Goal was to show equal nitrogen balance in hypocaloric

group (14 kcals/kg actual wt) vs control (25 kcals/kg actual wt)

• Protein intake was the same (2.0g/kg IBW) • Outcomes:

– No difference in % of patients achieving positive Nitrogen Balance – Weight change did not differ significantly between groups– Infections not measured– No difference in LOS or mortality

Choban et al, Am J Clin Nutr. 1997 Sep;66(3)

RCTs of Hypocaloric Nutrition in Obesity (2)

• 30 hospitalized obese patients (13 in the ICU)• Defined obesity as BMI >35 • Hypocaloric group -13.6kcals/kg actual wt • Control group – 22.5 kcals/kg actual wt• Protein intake was the same (2 g/kg IBW) • Outcomes:

– No difference in % of patients achieving positive Nitrogen Balance – Weight change did not differ significantly between groups– Infections not measured– No difference in LOS or mortality

Clinical Inferences to ICU Patients?

• N=46 (13 ICU patients)• Focus was on patients requiring PN, says

nothing about patients on EN• Focus was on NB, other outcomes not

assessed or underpowered.

Is there sufficient evidence that should inform one prescription on how ALL obese

patients should be fed?

Extreme Obesity and Outcomes in Critically Ill Patients

Martino Chest 2011;140:1198

Analysis of data from multicenter international observational study of ICU nutrition practices in 2007 and 2008

Increased obesity= increased risk of prolongation of stay

Not all critically ill obese patients are the same:

the influence of prior co-morbidities.

Raham ISRN Obesity 2012

0 1 2 3 4 5

0

5

10

15

Prospective observational study of 183 critically ill patients had a BMI ≥ 30

Not all critically ill obese patients are the same:

the influence of prior co-morbidities.

Raham ISRN Obesity 2012

0-1 co-morbidity

(n=38)

2 or more co-morbidities

(n=145)

p values

Discharged alive from ICU by day 28 36 (94.7%) 112 (77.2%) 0.02

Maximum SOFA score 7.5[5.0 to 11.0] 9.0[6.0 to 13.0] 0.04

Delta SOFA score 1.5[0.0 to 3.0] 2.0[1.0 to 5.0] 0.07

Number of days on MV 2.0[1.0 to 5.0] 4.0[2.0 to 7.0] 0.09

Number of days in ICU 3.0[3.0 to 11.0] 6.0[3.0 to 10.0] 0.04

ICU free days in the first 28 days 24.5[17.0 to 25.0]20.0[3.0 to

24.0]0.003

Mortality at Day 14 2 (5.3%) 24 (16.6%) 0.08

Mortality at Day 28 2 (5.3%) 30 (20.7%) 0.03

Not all critically ill obese patients are the same:

the influence of prior co-morbidities.

Raham ISRN Obesity 2012

In the adjusted analysis, compared to patients with limited co-morbidities, obese patients with multiple co-morbidities were:

• more likely to die at 28 days (OR 4.28, 95%CI, CI 0.92, 20.02, p=0.06)• tended to have longer ICU duration (3.06 days, standard error [SE] 2.28, p=0.18) and • had significantly fewer ICU free days in the first 28 days (-3.92 days, SE 1.83, p=0.03).

ICU Obese patients are not all created equal…should we expect the impact of

nutrition therapy to be the same across all patients?

Start EN within 24-48 hrs of admission to ICU

Optimal Amount of Protein and Calories for Critically Ill Patients

Bias and accuracy of common estimation methods for resting metabolic rate in

mechanically ventilated critically ill patients

Bias and accuracy of common estimation methods for resting metabolic rate in

mechanically ventilated critically ill patients

Curr Opin Crit Care 2012, 18:174–177

Penn State or modified Penn State if >60 recommended by experts*

*Choban JPEN 2013

Increasing Calorie Debt Associated with worse Outcomes

Caloric debt associated with: Longer ICU stay

Days on mechanical ventilation Complications

Mortality

Adequacy of EN

Rubinson CCM 2004; Villet Clin Nutr 2005; Dvir Clin Nutr 2006; Petros Clin Nutr 2006

0200

400600

8001000

12001400

16001800

2000

1 3 5 7 9 11 13 15 17 19 21

Days

kcal

Prescribed Engergy

Energy Received From Enteral Feed

Caloric Debt

• Point prevalence survey of nutrition practices in ICU’s around the world conducted Jan. 27, 2007

• Enrolled 2772 patients from 158 ICU’s over 5 continents

• Included ventilated adult patients who remained in ICU >72 hours

How are Obese Patients Actually Being Fed?

Total 25-<30 30-<35 35<-40 >=40 P-valueNutritional Prescription

Mean Energy [Kcal/kg/day] (SD) 24.0 (5.8) 23.8 (3.7) 20.2 (3.4) 17.9 (2.8) 15.0 (4.0) <0.0001

Mean Protein [grams/kg/day] (SD) 1.2 (0.3) 1.2 (0.3) 1.0 (0.2) 0.9 (0.2) 0.8 (0.3) <0.0001

Nutrition Received

Mean Energy [Kcal/kg/day] (SD) 14.0 (7.6) 13.6 (6.7) 11.2 (5.9) 9.8 (5.1) 8.1 (4.4) <0.0001

Mean Protein [grams/kg/day] (SD) 0.6 (0.4) 0.6 (0.3) 0.5 (0.3) 0.4 (0.3) 0.4 (0.3) <0.0001

Received EN protein supplements173 (6.2%) 50 (6.1%) 28 (7.1%) 17 (10.5%) 22 (12.9%) 0.0002

Hypothesis

• There is a relationship between amount of energy and protein received and clinical outcomes (mortality and # of days on ventilator)

• The relationship is influenced by nutritional risk

• BMI is used to define chronic nutritional risk

What Study Patients Actually Rec’d

• Average Calories in all groups: – 1034 kcals and 47 gm of protein

Result:

• Average caloric deficit in Lean Pts:– 7500kcal/10days

• Average caloric deficit in Severely Obese:– 12000kcal/10days

BMI Group

Adjusted

Estimate

95% CI P-value

LCL UCL

Overall 3.5 1.2 5.9 0.003

<20 2.8 -2.9 8.5 0.337

20-<25 4.7 1.5 7.8 0.004

25-<30 0.1 -3.0 3.2 0.958

30-<35 -1.5 -5.8 2.9 0.508

35-<40 8.7 2.0 15.3 0.011

>=40 6.4 -0.1 12.8 0.053

Relationship Between Increased Energy and Ventilator-Free days

Legend: # of VFD per 1000 kcals received per day adjusting for nutrition days, BMI, age, admission category, admission diagnosis and APACHE II score.

More (and Earlier) is Better!

If you feed them (better!)They will leave (sooner!)

ICU Obese patients are not all created equal…should we expect the impact of

nutrition therapy to be the same across all patients?

Muscle Matters!Skeletal muscle mass predicts ventilator-free days, ICU-

free days, and mortality in elderly ICU patients

• Patients > 65 years with an admission abdominal computed tomography scan and requiring intensive care unit stay at a Level I trauma center in 2009-2010 were reviewed.

• Muscle cross-sectional area at the 3rd lumbar vertebra was calculated and sarcopenia identified using sex-specific cut-points.

• Muscle cross-sectional area was then related to clinical parameters including ventilator-free days, ICU-free days, and mortality.

Moisey Crit Care 2013 Sept;17(5):R206

Skeletal Muscle

Adipose Tissue

Physical Characteristics of Patients

• N=149 patients

• Median age: 79 years old

• 57% males

• ISS: 19

• Prevalence of sarcopenia: 71%

BMI Characteristics

All Patients Sarcopenic Patients (n=106)

Non-sarcopenic Patients (n=43)

BMI (kg/m2) 25.8 (22.7, 28.2) 24.4 (21.7, 27.3) 27.6 (25.5, 30.4)

Underweight, % 7 9 2

Normal Weight, % 37 44 19

Overweight, % 42 38 51

Obese, % 15 9 28

Almost half the sarcopenic patients were overweight

Low muscle mass associated with mortality

Proportion of Deceased Patients

P-value

Sarcopenic patients 32%0.018

Non-sarcopenic patients 14%

Muscle mass is associated with ventilator-free and ICU-free

days

All Patients Sarcopenic Patients

Non-Sarcopenic

Patients

P-value

Ventilator-free days

25 (0,28) 19 (0,28) 27 (18,28) 0.004

ICU-free days 19 (0,25) 16 (0,24) 23 (14,27) 0.002

Nutrition Statusmicronutrient levels - immune markers - muscle mass

Acute Starvation

(Reduced po intake, pre ICU hospital stay)

Chronic Malnutrition(?Sarcopenia)

Severity of Illness

(APACHE, SOFA, IL-6)

Pre-existing Co-morbidities(Metabolic

consequences)

What does Nutrition Risk Assessment look like for the obese critically ill?

Functional Impairment

(reduced mobility and strength)

Risk StatusHigh risk= high risk of death and greater likelihood

of benefit from Nutrition

Degree of Obesity(BMI)

A Proposed Clinical Staging System for Obesity

(non-critically ill)

Sharma Int J of Obesity 2009;33:289

Increasing complications

Increasing aggressiveness

We need to adapt this way of thinking to the ICU setting!

What if you can’t provide adequate nutrition enterally?

… to add PN or not to add PN,

that is the question!

Role of PN in the Obese Patient?

Early vs. Late Parenteral Nutrition in Critically ill Adults

• 4620 critically ill patients

• Randomized to early PN

– Rec’d 20% glucose 20 ml/hr then PN on day 3

• OR late PN

– D5W IV then PN on day 8

• All patients standard EN plus ‘tight’ glycemic control

Cesaer NEJM 2011

• Results:

Late PN associated with

• 6.3% likelihood of early discharge alive from ICU and hospital

• Shorter ICU length of stay (3 vs 4 days)

• Fewer infections (22.8 vs 26.2 %)

• No mortality difference

Early vs. Late Parenteral Nutrition in Critically ill Adults

• ? Applicability of data– No one give so much IV glucose in first few days– No one practice tight glycemic control

• Right patient population?– Majority (90%) surgical patients (mostly cardiac-60%)– Short stay in ICU (3-4 days)– Low mortality (8% ICU, 11% hospital)– >70% normal to slightly overweight

• Not an indictment of PN– Early group only rec’d PN for 1-2 days on average– Late group –only ¼ rec’d any PN

Cesaer NEJM 2011

Lancet Dec 2012

Doig, ANZICS, JAMA May 2013

What if you can’t provide adequate nutrition enterally to critically ill obese patient??

… to supplement with PN or not to PN,

that is the question!

Case by Case DecisionMaximize EN delivery prior

to initiating PN

High-riskICU patients

BMI <25 R

PN for 7 days

EN Alone

The TOP UP Trial

Inadequately fed enterally in first 2 days (<60%)

Primary Outcome

60-day mortality

BMI >35

Stratified by:SiteBMI

Med vs Surg

HYPOTHESIS

Increased early energy and protein delivery with PN+EN to underweight

(BMI < 25) and obese (BMI> 35) critically ill patients will result in

improved survival at 60 day versus standard EN alone

Key Methodological Features

• Only enrolling nutrition ‘at risk’ patients not tolerating EN within first 48 hrs.

• Paired EN/PN feeding to meet goal rate of protein/calories from initiation vs. EN alone x 7 days

• High nitrogen PN solution with olive oil (Olimel, 3 in 1, Baxter)

• Comprehensive assessment of muscle mass and muscle function

In Conclusion

• Not all Obese ICU patients are the same in terms of ‘risk’- need to develop and validate risk assessment tools in this population

• Iatrogenic underfeeding is harmful to some Obese ICU patients or some will benefit more from aggressive feeding (avoiding protein/calorie debt)

• Aggressive use of EN (high protein diets) and protein supplements indicated

• Supplemental PN may be beneficial in some