Download Hypothermia and SSI

Hypothermia and SSI
Claude Laflamme MD, FRCPC
Director Cardio-vascular anesthesia
Assistant Professor U of Toronto
Surgical site infection (SSI)
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30,000,000 operations/year in USA
2% = 600,000 have SSI
Increases in mortality
Increases readmission rates
Increases LOS by an average of 7
days
• Increases cost to more than $30,000
Patient and operation
characteristics that may influence
the SSI rates
Patient
Operation
Post-op care
Age
Antiseptic technique
Wound care
Nutritional status
Surgical technique
Discharge
Diabetes
Wound classification
Smoking
Length of surgery
Obesity
Antimicrobial prophylaxis
Steroid use
Hair removal, BG,
Prolonged pre-op LOS
Normothermia,
Blood transfusion
Complications of mild hypothermia
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Increases duration of hospitalization
Increases intra-operative blood loss
Increases adverse cardiac event
Increases patient shivering in PACU
Increases SSI rates
Perioperative hypothermia
• GA alters central thermoregulation
• Thermoregulatory responses are triggered
after 2-3ºC of hypothermia (±34ºC)
• Core temperature decreases by 1ºC within
30 minutes of induction
• Heat production decreases by 5%/ºC in
the absence of shivering
• Enhanced heat loss
Normothermia for colorectal
surgery
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A Kurz, NEJM 1996; 334:1209-15
200 patients, double-blind study
Followed for 2 weeks
34.7±0.6 Celsius VS 36.6±0.5 Celsius
SSI 18.8% VS 5.8% (p=0.009)
Sutures were removed one day later
(p=0.002)
• Hospital LOS prolonged by 2.6 days
(p=0.01)
Normothermia for colorectal
surgery
• 1.9ºC core hypothermia triples the
incidence of surgical wound infection after
colon resection
• Hypothermia increases by 20% the
duration of hospitalization
Normothermia for colorectal
surgery
• A Kurz, NEJM 1996; 334:1209-15
• Intraoperative vasoconstriction was present
in 74% vs 6% of patients and persisted
throughout the 6 hr recovery period
Hypothermia and cholecystectomy
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Flores-Maldonado et al. 2001
290 consecutive patients
30-day follow-up
Patients that received blood transfusion
were excluded
• 35.4º±0.4ºC vs 36.2º±0.2ºC
• 11.5% vs 2% SSI
What do I do now?
Realistic options
• Get the department of Anesthesiology on
board
• Listen to their concerns about SSI
• Provide support to address their concerns
• Choose your battles
• Emphasize on the critical role they play on
SSI
Patient and operation
characteristics that may influence
the SSI rates
Patient
Operation
Post-op care
Age
Antiseptic technique
Wound care
Nutritional status
Surgical technique
Discharge
Diabetes
Wound classification
Smoking
Length of surgery
Obesity
Antimicrobial prophylaxis
Steroid use
Hair removal, BG,
Prolonged pre-op LOS
Normothermia,
Blood transfusion
The Anesthesiologist’s Role
Anesthesiology 2006; 105:413-21
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Hypothermia
Hyperoxia
Fluid Management
Hyperglycemia
Blood transfusion
Antimicrobial Prophylaxis
CSI: Hypothermia
Complications and treatment of
mild hypothermia
Anesthesiology 2001; 95:531-43
• Myocardial Ischemia
Frank et al. JAMA 1997;277:1127-34
High risk patients assigned to 1.3ºC core
hypothermia were three times as likely to
experienced adverse cardiac outcome
• Cold-induced hypertension is associated
with a threefold increase in plasma
norepinephrine concentrations
Complications and treatment of
mild hypothermia
• Coagulopathy
• Platelet dysfunction (reduction in the
release of thromboxane A2
• Clotting factor enzyme
• Fibrinolytic activity-TEG
Complications and treatment of
mild hypothermia
Hypothermia
Impairs neutrophils
function
Vasoconstriction
Tissue hypoxia
Hypothermia
• Vasoconstriction
Decreases the partial pressure of oxygen in
tissues which impairs the oxidative killing by
neutrophils
Reduces the deposition of collagen
• Impairs immunity
Chemo taxis and phagocytosis of
granulocytes motility of macrophages
Production of antibody
Reduces the production of super oxide
radicals
Hypothermia
• Animal study
• Hypothermia increased levels of
interleukin 10 and decreased levels of
interleukin 2
• This profile is similar to other proinfectious
state as burn and hemorrhagic choc.
Hopf et al, Arch Surg 1997
• Subcutaneous oxygen tension at
surrogate wound inversely correlated with
the risk of SSI
• S/C O2 40-50mmHg had a SSI of 43%
• S/C O2 above 90 mmHg had no SSI
Complications and treatment of
mild hypothermia
• Pharmacokinetics and Pharmacodynamics
Reduces clearance during hypothermia
• Prolongs PACU stay
Minimizing hypothermia
• Anesthetics profoundly inhibits central
thermoregulation decreasing the
vasoconstriction threshold by 2-4ºC
• The second major factor is the magnitude of the
core-to-peripheral temperature gradient
• Minimizing the core-to-peripheral temperature
gradient and preoperative vasodilatation, is the
basis to reduce heat redistribution
• Degree of adiposity, concurrent medication
Minimizing hypothermia
• Prewarming: Decreases core-to-peripheral
temperature gradient
Eventually provokes
vasodilatation
• Pharmacologic vasodilatation
Cutaneous warming
• Passive insulation reduces heat loss by
approximately 30%
• Active cutaneous heating: efficacy will be
proportional to the skin surface warmed
Circulating water, Forced air, Radiant
warmers
Active cutaneous warming systems
• Forced-air systems
• Circulating-water mattresses
• Resistive heating systems (ICU,trauma)
Carbon-fiber patient cover
• Circulating-water garments
Water has a conductivity of heat 26 times
higher than air
• Infrared radiation(neonats, pediatric Sx)
Core temperature monitoring
• Pulmonary artery
• Nasopharynx
• Tympanic membrane
Aural thermocouples probe
Infrared thermometer
• Distal Oesophagus
• Rectal temperature during neuraxial
anesthesia
Fluid warming
• If more than 2 liters/hr
• One liter of crystalloid or 1 unit of
refrigerated blood decreases core
temperature by 0.25ºC
Safer Healthcare Now! Campaign
Sunnybrook and Women's College
Health Scienc es Ce ntre
Data Colle ction Record
BRADMA
SSI BUNDLE
Sugery Date
Procedure
Sug ery Date Cop y
DD
MM M
YYYY
Procedure
Normothermia
Is Temperature >= 36 o on leaving OR
Yes
No
Temperature
OR Temp
Yes
No
Temperature
PACU Temo
OR
o
Is Temperature >= 36 on Arrival in PACU
Infection rates in colorectal
Infection No Infection
Total
Hypothermic
N=13
46.4%
N=15
53.6%
N=28
Normothermic
N=2
12.5%
N=14
87.5%
N=16
Total
N=15
N=29
N=44
P=0.022
Quarterly Incidence of Infections
Among Isolated ACB’s 2004-2005
20
SSI Rate (%)
15
10
5
0
1st
Quarter
2004
2nd
Quarter
3004
3rd
Quarted
2004
4th
Quarter
2004
1st
Quarter
2005
2nd
Quarter
2005
3rd
Quarter
2005
4th
Quarter
2005
Quiz
• Is prewarming useful?
• Is postoperative rewarming efficient?
• Do you believe that an open
cholecystectomy carries approximately the
same risk of hypothermia than a
laparascopic cholecystectomy?
• What is the future of normothermia in your
OR?
Quiz
• What is the definition of intraoperative
hypothermia?
• Is intravenous fluid warming helpful?
• How do you mesure the temperature to
reflect core temperature reliably?