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!

2. BMI can we squeeze themBMI can we squeeze them
in?in?

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

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

9. BMI DefinitionsBMI Definitions
BMI (kg/mBMI (kg/m22
)) DescriptorDescriptor
 <20<20 UnderweightUnderweight
 20-24.920-24.9 IdealIdeal
 25-29.925-29.9 OverweightOverweight
 30-39.930-39.9 ObeseObese
 40-49.940-49.9 Morbidly obeseMorbidly obese
 50-59.950-59.9 Super obeseSuper obese
 60-69.960-69.9 Super Super obeseSuper Super obese
 >70>70 Hyper obeseHyper obese

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

13. Risks of obesityRisks of obesity
 SmokingSmoking
 Duration of obesityDuration of obesity
“obese years”“obese years”
 Fat distrubutionFat distrubution
 Android “appleAndroid “apple
shaped’’shaped’’
 Increased airway fatIncreased airway fat
 CVSCVS
 RespiratoryRespiratory
 Gynacoid “pearGynacoid “pear
shaped”shaped”

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”

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

27. TracheostomyTracheostomy

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

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%

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

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

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

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

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

56. Increasing risk of death with BMIIncreasing risk of death with BMI

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!