Gordon Flynn is an Intensivist and an Anaesthetist from Prince of Wales hospital in Sydney. Here he gives an entertaining and thought provoking talk on the big topic of obesity in ICU. Leave comments below on ICN!
April 2024 ONCOLOGY CARTOON by DR KANHU CHARAN PATRO
Flynn - Obesity in ICU
1.
2. BMI can we squeeze themBMI can we squeeze them
in?in?
3.
4. ObjectivesObjectives
Increasing prevalence of obesityIncreasing prevalence of obesity
Definition and types of obesityDefinition and types of obesity
Pathophysiology of obesityPathophysiology of obesity
Effects on drug distribution and handlingEffects on drug distribution and handling
Physical challenges of the bariatric patientPhysical challenges of the bariatric patient
5. Size of the problem!Size of the problem!
Growing epidemic in developed countriesGrowing epidemic in developed countries
Estimated 250 million obese people worldwideEstimated 250 million obese people worldwide
In the USA 66% of the adult population are overweightIn the USA 66% of the adult population are overweight
and make up 30% of ICU admissions.and make up 30% of ICU admissions.
Obesity is a global epidemicObesity is a global epidemic
WHO estimates in 2002 there were 2.5 million weightWHO estimates in 2002 there were 2.5 million weight
related deathsrelated deaths
Problem of social and psychological dimension thatProblem of social and psychological dimension that
affects all ages and socioeconomic groupsaffects all ages and socioeconomic groups
Australia by 2010 predicted prevalence of BMI >30Australia by 2010 predicted prevalence of BMI >30
kg/m2kg/m2
27.4% of males27.4% of males
29.1% of females29.1% of females
6.
7.
8. Quetelet IndexQuetelet Index
Category BMI range -kg/mCategory BMI range -kg/m22
Starvation less than 14.9Starvation less than 14.9
Underweight from 15 to 18.4Underweight from 15 to 18.4
Normal from 18.5 to 24.9Normal from 18.5 to 24.9
Overweight from 25 to 29.9Overweight from 25 to 29.9
Obese from 30 to 39.9Obese from 30 to 39.9
Morbidly Obese greater than 40Morbidly Obese greater than 40
12. ObesityObesity
Waist circumference >102cm in Males andWaist circumference >102cm in Males and
>88cm in females indicates high risk of>88cm in females indicates high risk of
metabolic and cardiovascular complicationsmetabolic and cardiovascular complications
18. Outcomes from ICUOutcomes from ICU
APACHE and SAPS scoring do not take BMIAPACHE and SAPS scoring do not take BMI
into account.into account.
Several studies looking at obesity and risk ofSeveral studies looking at obesity and risk of
death with conflicting results.death with conflicting results.
Two recent meta-analyses demonstrated noTwo recent meta-analyses demonstrated no
difference in mortality between critically ill obesedifference in mortality between critically ill obese
and those with a normal BMI.and those with a normal BMI.
There may even be an improved survivalThere may even be an improved survival
““The Obesity Survival Paradox”The Obesity Survival Paradox”
19.
20. Causes of obesityCauses of obesity
GeneticGenetic
EnvironmentalEnvironmental
PsychologicalPsychological
SocialSocial
Control of appetite and satietyControl of appetite and satiety
Lectin, adiponectin, insulin, ghrelin, peptide YYLectin, adiponectin, insulin, ghrelin, peptide YY
Leptin satiety, decreases appetiteLeptin satiety, decreases appetite
ObeseObese
increased leptin (produced by adipose cells)increased leptin (produced by adipose cells)
Decreased sensitivity to leptinDecreased sensitivity to leptin
21. Pathophysiology of obesityPathophysiology of obesity
Type II diabetesType II diabetes
HypertensionHypertension
Heart disease and strokeHeart disease and stroke
OsteoarthritisOsteoarthritis
DyslipidaemiaDyslipidaemia
Cancer (endometrial breast and colon)Cancer (endometrial breast and colon)
Liver diseaseLiver disease
Obesity hypoventilation syndromeObesity hypoventilation syndrome
22. Drug administration and kineticsDrug administration and kinetics
Increased body massIncreased body mass
Fat distribution in organsFat distribution in organs
Increased blood volumeIncreased blood volume
Increased muscle massIncreased muscle mass
Increased clearanceIncreased clearance
Decreased water to lipid ratioDecreased water to lipid ratio
23. PharmacokineticsPharmacokinetics
Lipophilic drugs Total body weightLipophilic drugs Total body weight
BenzodiazepenesBenzodiazepenes
PropofolPropofol
Fentanyl – loading dose TBW then IBWFentanyl – loading dose TBW then IBW
Hydrophobic drugsHydrophobic drugs
Neuromuscular blockers IBWNeuromuscular blockers IBW
Vancomycin TBWVancomycin TBW
Gentamicin / ciprofloxacin IBW + fractionGentamicin / ciprofloxacin IBW + fraction
Increased renal and hepatic clearanceIncreased renal and hepatic clearance
(increased blood flow)(increased blood flow)
24. Ideal body weightIdeal body weight
Mathematical conceptMathematical concept
Brocca (French surgeon 1871)Brocca (French surgeon 1871)
Wt (kg) = ht (cm) – 100 = ideal body wtWt (kg) = ht (cm) – 100 = ideal body wt
+/- 15% for women and 10% for men+/- 15% for women and 10% for men
““Corrected” body weight = IBW + 40%Corrected” body weight = IBW + 40%
excessexcess
25. NutritionNutrition
Prone to protein malnutrition as a result ofProne to protein malnutrition as a result of
metabolic stressmetabolic stress
Elevated basal insulin, supresses lipolysisElevated basal insulin, supresses lipolysis
leading to accelerated conversion ofleading to accelerated conversion of
protein to glucoseprotein to glucose
Start feeding within 24 hours of admissionStart feeding within 24 hours of admission
Most calories should be carbs and fat toMost calories should be carbs and fat to
prevent FFA deficiencyprevent FFA deficiency
Hypo caloric feeding maybe beneficialHypo caloric feeding maybe beneficial
Dickerson RN, Boschert KJ,Kudsk KA, Brown RO. Hypocaloric enteral tube feeding inDickerson RN, Boschert KJ,Kudsk KA, Brown RO. Hypocaloric enteral tube feeding in
26. AirwayAirway
PositionPosition
TongueTongue
EquipmentEquipment
Mouth openingMouth opening
Short neckShort neck
Neck circumferenceNeck circumference: 5%: 5%
chance difficult intubationchance difficult intubation
if > 40cmif > 40cm butbut 35%35%
chance if >60cm!chance if >60cm!
Best indicator of potentialBest indicator of potential
difficult airwaydifficult airway
STOPBANG risk of OSASTOPBANG risk of OSA
28. Respiratory systemRespiratory system
VentilationVentilation
Position ReversePosition Reverse
Trendelenburg,Trendelenburg,
FRC decreases withFRC decreases with
increasing BMI,increasing BMI,
increased A-aincreased A-a
gradient,gradient,
Rapidly desaturateRapidly desaturate
29. Respiratory systemRespiratory system
Restrictive lung diseaseRestrictive lung disease
Decreased chest wall complianceDecreased chest wall compliance
Diaphragm forced cephaladDiaphragm forced cephalad
Decreased lung volumesDecreased lung volumes
Accentuated by supine and TrendelenbergAccentuated by supine and Trendelenberg
positionspositions
FRC may fall below closing capacityFRC may fall below closing capacity
Alveolar collapseAlveolar collapse
Ventilation / perfusion mismatchVentilation / perfusion mismatch
30.
31.
32. Cardiovascular PathophysiologyCardiovascular Pathophysiology
For every 13.5 kg of fat gained:For every 13.5 kg of fat gained:
25 miles of neovascularization occurs25 miles of neovascularization occurs
Increased blood volumeIncreased blood volume
Increased CO of 0.1 L/min for each kg of fat.Increased CO of 0.1 L/min for each kg of fat.
The blood volume and CO of a person weighingThe blood volume and CO of a person weighing
170 kg are twice that of a 70 kg person170 kg are twice that of a 70 kg person
Regional blood flows are normal, except in theRegional blood flows are normal, except in the
splanchnic bed where it is increased 20%splanchnic bed where it is increased 20%
33.
34. CardiovascularCardiovascular
HypertensiveHypertensive
Difficult to measure BPDifficult to measure BP
Difficult to measure saturationsDifficult to measure saturations
Cardiopulmonary resuscitationCardiopulmonary resuscitation
Pulmonary hypertension right ventricularPulmonary hypertension right ventricular
failurefailure
Fatty infiltration of the myocardiumFatty infiltration of the myocardium
35.
36. Nutrition and metabolismNutrition and metabolism
Malnourished group of patientsMalnourished group of patients
Metabolic syndromeMetabolic syndrome
ObesityObesity
Insulin resistanceInsulin resistance
DyslipidaemiaDyslipidaemia
HyperglycaemiaHyperglycaemia
Proteolytic rather than lipolyticProteolytic rather than lipolytic
Feed regimesFeed regimes
15-20kcal/kg/day IBW15-20kcal/kg/day IBW
Protein 1.5-2g/kg/day IBWProtein 1.5-2g/kg/day IBW
Essential fatty acidsEssential fatty acids
37. Beauty is in the eye of theBeauty is in the eye of the
beholder.beholder.
38. Optimal PositioningOptimal Positioning
Least beneficialLeast beneficial
Supine, Trendelenburg, lithotomy, proneSupine, Trendelenburg, lithotomy, prone
Promote dyspnea, atelectasis, hypoxemiaPromote dyspnea, atelectasis, hypoxemia
Most beneficialMost beneficial
Lateral decubitusLateral decubitus
Displaces the abdomen and allows greater diaphragmDisplaces the abdomen and allows greater diaphragm
excursionexcursion
303000
-45-4500
semirecumbant positionsemirecumbant position
After gastric surgeryAfter gastric surgery
39.
40.
41. Positioning and RehabilitationPositioning and Rehabilitation
Back injuries to staff is a real and constant threatBack injuries to staff is a real and constant threat
Scheduled positioning imperative:Scheduled positioning imperative:
Takes 5 staff to move patient, 3 staff if using aTakes 5 staff to move patient, 3 staff if using a
specialized moving mattressspecialized moving mattress
Physical Therapist provides education related toPhysical Therapist provides education related to
correct body mechanics to prevent injury to staffcorrect body mechanics to prevent injury to staff
and patientand patient
42.
43. Physical AssessmentPhysical Assessment
BPBP: use thigh cuff or regular cuff on forearm: use thigh cuff or regular cuff on forearm
Breath soundsBreath sounds: displace skin folds: displace skin folds
Bowel soundsBowel sounds: girth measurements accurately: girth measurements accurately
identify distentionidentify distention
HeartHeart: auscultate over L lateral chest when pt is: auscultate over L lateral chest when pt is
turned toward L sideturned toward L side
ABGs more reliable that pulse oximeter due toABGs more reliable that pulse oximeter due to
poor peripheral perfusionpoor peripheral perfusion
Hurst S et al (2004)Hurst S et al (2004)
44. Procedures and DiagnosticProcedures and Diagnostic
TestingTesting
Before ordering & transporting patientBefore ordering & transporting patient
Assure the diagnostic site and equipment canAssure the diagnostic site and equipment can
accommodate pts sizeaccommodate pts size
Consult with the techs beforehandConsult with the techs beforehand
Many recommend transport in patient’s bedMany recommend transport in patient’s bed
Be aware that some elevators may not accommodateBe aware that some elevators may not accommodate
weight of bed, patient, equipment and caregiversweight of bed, patient, equipment and caregivers
45.
46. Prevention of VTEPrevention of VTE
Pulmonary EmbolismPulmonary Embolism
Morbid obesity is an independent risk factorMorbid obesity is an independent risk factor
Primary prevention is key (Mobilization)Primary prevention is key (Mobilization)
Obese patient excluded from trials on effectiveObese patient excluded from trials on effective
prophylactic regimenprophylactic regimen
LMWH Study: nonrandomized prospective study ofLMWH Study: nonrandomized prospective study of
481 bariatric surgery pts (BMI> 50 kg/m2)481 bariatric surgery pts (BMI> 50 kg/m2)
40 mg q 12 hrs was superior to 30 mg q 12 hrs40 mg q 12 hrs was superior to 30 mg q 12 hrs
No difference in bleeding events reportedNo difference in bleeding events reported
Sholten DJ et al (2002)Sholten DJ et al (2002)
IV heparin: weight based dosing, need frequent aPPTIV heparin: weight based dosing, need frequent aPPT
monitoringmonitoring
47. Venous AccessVenous Access
Central linesCentral lines
Obese patients have double the use and lines are inObese patients have double the use and lines are in
longer than non-obese ptslonger than non-obese pts
One study suggests no difference in mechanicalOne study suggests no difference in mechanical
insertion complication rateinsertion complication rate
El-Solh A et al (2001)El-Solh A et al (2001)
Switch to PICC lines as soon as possibleSwitch to PICC lines as soon as possible
48. Impact of Obesity inImpact of Obesity in
mechanically ventilated patients:mechanically ventilated patients:
a prospective studya prospective study
Intensive care medicine 2008 34:1991-1998Intensive care medicine 2008 34:1991-1998
French studyFrench study
MeasurementsMeasurements
Tracheal intubationTracheal intubation
Catheter placementCatheter placement
Nosocomial infectionsNosocomial infections
Development of pressure ulcersDevelopment of pressure ulcers
ICU and hospital outcomeICU and hospital outcome
49. ResultsResults
82 severely obese patients (mean BMI 42+/- 682 severely obese patients (mean BMI 42+/- 6
kg/mkg/m22
))
124 non-obese patients (mean BMI 24 +/- 4124 non-obese patients (mean BMI 24 +/- 4
kg/mkg/m22
))
ICU course the same exceptICU course the same except
Difficulties during tracheal intubation (15 vsDifficulties during tracheal intubation (15 vs
6%)6%)
Post extubation stridor (15 vs 3%)Post extubation stridor (15 vs 3%)
P<0.05P<0.05
Mortality rates (24 and 25%)Mortality rates (24 and 25%)
No difference in risk-adjusted hospital mortalityNo difference in risk-adjusted hospital mortality
50. Obesity is associated with increasedObesity is associated with increased
morbidity but not mortality in critically illmorbidity but not mortality in critically ill
patientspatients
Intensive care medicine 2008 34:1999-2009Intensive care medicine 2008 34:1999-2009
Data from the SOAP studyData from the SOAP study
ResultsResults
198 ICUs in 24 European countries198 ICUs in 24 European countries
BMI available in 2878 pts (91%) of the 3147BMI available in 2878 pts (91%) of the 3147
SOAP study ptsSOAP study pts
120 patients 4.2% underweight120 patients 4.2% underweight
1206 patients 41.9% normal BMI1206 patients 41.9% normal BMI
1047 patients 36.4% overweight1047 patients 36.4% overweight
424 patients 14.7% obese424 patients 14.7% obese
81 patients 2.8% very obese81 patients 2.8% very obese
51. ResultsResults
Obese and very obese BMI>30Obese and very obese BMI>30
More frequent ICU acquired infectionsMore frequent ICU acquired infections
Very obese BMI>40Very obese BMI>40
Trend towards longer ICU and hospitalTrend towards longer ICU and hospital
lengths of staylengths of stay
4.1 (1.8-12.1) vs 3.1 (1.7-7.2) p=0.0564.1 (1.8-12.1) vs 3.1 (1.7-7.2) p=0.056
14.3 (8.4-27.4) vs 12.3 (5.1-24.4) p=0.07714.3 (8.4-27.4) vs 12.3 (5.1-24.4) p=0.077
No significant differences in mortality ratesNo significant differences in mortality rates
None of the BMI categories was associated withNone of the BMI categories was associated with
an increased risk of 60-day in hospital deathan increased risk of 60-day in hospital death
57. ConclusionConclusion
The only difference in morbidity of obeseThe only difference in morbidity of obese
patients who were mechanically ventilatedpatients who were mechanically ventilated
was increased difficulty with intubation andwas increased difficulty with intubation and
higher incidence of post extubation stridor.higher incidence of post extubation stridor.
BMI did not significantly impact onBMI did not significantly impact on
mortality in this mixed population of ICUmortality in this mixed population of ICU
patientspatients
58. SummarySummary
Increasing prevalence of obesityIncreasing prevalence of obesity
Definition and types of obesityDefinition and types of obesity
Pathophysiology of obesityPathophysiology of obesity
Effects on drug distribution and handlingEffects on drug distribution and handling
Physical challenges of the bariatric patientPhysical challenges of the bariatric patient
There really is no increase in mortality!There really is no increase in mortality!