anesthesie en outcome na abdominale heelkunde

Anesthesie en Outcome na Majeure Abdominale Heelkunde

Kan het peroperatieve anesthesiebeleid tijdens majeure (niet-vasculaire)

abdominale heelkunde de postoperatieve outcome beïnvloeden?

M. Verhaegen

Vrijdagochtendkrans 05-09-2008

Postoperative Morbidity and Mortality and the Surgical Procedure

Vascular surgery Myocardial infarction

Total hip or knee replacement Pulmonary embolism

Thoracic or upper abdominal surgery Pneumonia

Major Abdominal Surgery (MAS):Postoperative Morbidity

Pulmonary complications Cardiovascular complications Prolonged ileus Anastomotic leaks

Fistulae Peritonitis

Surgical wound infections Colon surgery: 10 – 30 % Prolonged hospitalization (5 – 20 days) Increased cost

Nausea and vomiting Pain

Anesthesia for MAS

Induction of anesthesia Anesthetic technique Intraoperative fluid management Optimal perioperative oxygen concentration Muscle relaxation / antagonism Blood transfusion Body temperature Postoperative analgesia

Surgery, Anesthesia and Outcome

Patient safety Mortality Major morbidity

Patient satisfaction Minor morbidity Side effects

Economic benefits


Patient safety Mortality

Major morbidity Patient satisfaction

Minor morbidity Side effects

Economic benefits

Mortality rate contribution

Patient 1 in 870

Surgery 1 in 2860

Anesthesia 1 in 185 256

Confidential enquiry into perioperative deaths (Lancet 1987)

Major Abdominal Surgery (MAS) and

Epidural Anesthesia and Analgesia (EAA):

What are the benefits?

MAS and EAA: Postoperative Effects (1)

Epidural analgesia provides superior postoperative analgesia Local anesthetic ± opioid compared to systemic opioids For up to 72 h postoperatively Especially during movement, coughing Part of multimodal postoperative rehabilitation programmes

Improved exercise capacity and vitality for 6 w postoperatively Faster recovery of bowel function

Thoracic epidural with local anesthetics lasting > 24 h, compared to postoperative analgesia with systemic opioids

No increased incidence of anastomotic leaks

Meta-analysis of 16 prospective RCTs (1985-2005) comparing postoperative epidural analgesia and parenteral opioid analgesia after colorectal surgery

EA: Epidural analgesia (local anesthetic ± opioid): n = 406 Control: Parenteral (non)opioid analgesia: n = 400

Primary outcome: length of hospital stay Secondary outcomes

Postoperative pain (VAS score at 24 and 48 h) Recovery of bowel function Anastomotic leakage Cardiac complications Respiratory complications Nausea and vomiting Sedation Pruritus Urinary retention Hypotension

Marret et al., Br J Surg (2007); 94: 665-73

Marret et al., Br J Surg (2007; 94: 665-73

Marret et al., Br J Surg (2007; 94: 665-73

Epidural Control

VAS at 24 h (mmHg) 12 18

VAS at 48 h (mmHg) 27 33

Duration of ileus - 36 h

Urinary retention 10 % 1 %

Pruritus 21 % 5 %

Hypotension 10 % 0 %


No reduction of postoperative mortality No reduction of major postoperative morbidity

Inconsistent results of many RCTs Meta-analyses

Meta-analysis of RTCs Randomisation to intraoperative neuraxial blockade or not

141 trials (1971-1995) 9559 patients (NB: 4871, no NB: 4688)

Outcome measures Mortality Morbidity

Neuraxial blockade Reduction of overall mortality by 1/3 Reduction of major morbidity by 40 – 60 %

Deep vein thrombosis Pulmonary embolism Perioperative blood loss Postoperative blood loss requiring transfusion Pneumonia Respiratory depression Renal failure

CORTRA, Rodgers et al., Br Med J (2000); 321: 1-12

Remarks General anesthesia or neuraxial anesthesia

Effect of avoidance of general anesthesia? LMWH is now more commonly used Improved surgical and anesthetic techniques Improved diagnostic techniques

Pulmonary atelectasis CT scan > chest X-ray

Myocardial damage Troponin Ic

CORTRA, Rodgers et al., Br Med J (2000); 321: 1-12

Meta-analyses of 65 RTCs (1966-1995) Significantly reduced incidence of atalectasis with epidural

opioids compared to systemic opioids 11 trials (1975-1995) Abdominal and thoracic surgery 769 patients

Significantly reduced the incidence of pulmonary infection or pulmonary complications in general with epidural local anesthetics

Pulmonary infection: 5 trials (1971-1987), n = 215 Pulmonary complications: 6 trials (1974-1987), n = 247

Ballantyne et al., Anesth Analg (1998); 86: 598-612



Inconsistent results of many RCTs Meta-analyses: problems

Older studies, not relevant to present-day practices, included Excessive heterogeneity (oversimplification of complex issues) Publication bias: tendency to publish only positive results Difficult quality assessment Definition of endpoints

Ballantyne et al., J Clin Anesth (2005); 17: 382-91



Inconsistent results Meta-analyses Studies investigating major abdominal surgery do not support

an effect on major morbidity Lack of power?

Multicentre trial (15) 1021 patients

Intraabdominal surgery Aortic (37 %), gastric, biliary or colon

Randomised to 1 of 2 groups Control: general anesth. + postoperative iv or im opioids

(PCA) (n = 507) General / epidural anesth. (local anesthetic ± morphine) +

postoperative epidural analgesia (morphine) (n = 514) Primary endpoints

Death within 30 days Major postsurgical morbidity within 30 days

Major cardiac, pulmonary, cerebrovascular or renal complications

Park et al., Ann Surg (2001); 234: 560-71

Significantly better postoperative pain control in the epidural group

No significant difference in overall physical performance (7 d) No significant difference in 30 day mortality

Control Epidural P value

All patients (n = 507 / 514) 3.3 % 3.9 % 0.74

Aortic (n = 190 / 184) 2.6 % 2.2 % 0.96

Nonaortic (n = 317 / 330) 3.8 % 4.8 % 0.64


Overall, no significant difference in major complications Nonaortic surgery: no significant difference Aortic surgery

Decreased incidence of myocardial infarction, respiratory failure, and stroke

Epidural patients were extubated 13 h earlier (p = 0.01)

Control Epidural P value

All patients (n = 507 / 514) 22 % 17 % 0.11

Nonaortic (n = 317 / 330) 13 % 15 % 0.42

Aortic (n = 190 / 184) 37 % 22 % < 0.01

New myocardial infarction 7.9 % 2.7 % 0.05

Respiratory failure 28 % 14 % < 0.01

New stroke 4.7 % 0.5 % 0.03


Multicentre (25 hospitals, 6 countries) 915 high-risk patients (at least 1 of 9 comorbid states)

Major abdominal or thoracic surgery Elective, non-laparoscopic, lasting > 1 h No cardiac or pulmonary procedures

Randomised to 1 of 2 groups Control: general anesth. + postoperative iv opioids (PCA)

and NSAIDs (n = 441) General / epidural anesthesia + postoperative epidural

analgesia (72 h, local anesthetic + opioid) (n = 447) Primary endpoints

Death within 30 days Major postsurgical morbidity

Rigg et al., Lancet (2002); 359

Rigg et al., Lancet (2002); 359No significant differences in allocation

Procedure n

Esophagectomy 18

Non-laparoscopic gastric surgery 72

Non-laparoscopic biliary surgery 77

Pancreatic surgery 35

Bowel surgery 364

Major surgery for ovarian cancer 23

Surgery for aortic aneurysm 142

Aorto-femoral bypass-graft surgery 28

Renal tract surgery 59

Bladder surgery 12

Prostate surgery 7

Radical hysterectomy 44

Pelvic exenteration 2

Other 36


No significant differences in allocation

Procedure n

Esophagectomy 18

Non-laparoscopic gastric surgery 72

Non-laparoscopic biliary surgery 77

Pancreatic surgery 35

Bowel surgery 364

Major surgery for ovarian cancer 23

Surgery for aortic aneurysm 142

Aorto-femoral bypass-graft surgery 28

Renal tract surgery 59

Bladder surgery 12

Prostate surgery 7

Radical hysterectomy 44

Pelvic exenteration 2

Other 36

71.3%

No significant differences in allocation

Epidural analgesia was associated with lower pain scores during the first 3 postoperative days

No significant difference in mortality at 30 days Control group: 4.3 % Epidural group: 5.1 %

No overall difference in major postoperative morbidity Patients who had at least one morbid endpoint: 60.5 % in the

control group vs 56.6 % in the epidural group (p = 0.26) Only respiratory failure occurred less frequently in patients

managed with epidural techniques: 23.3 % vs 30.2 % (p = 0.02)


Selected number of predetermined subgroup analyses of Rigg et al. trial:• Increased risk of respiratory complications• Increased risk of cardiac complications• Aortic surgery

Respiratory failure = Need for ventilation > 1 h after surgery, or reintubation of PaO2 ≤ 50 mmHg or PaCO2 ≥ 50 mmHg on room air

Peyton et al., Anesth Analg (2003); 96: 548-54

The only significant difference between epidural and control groups was respiratory failure.

70 ASA I or II patients > 70 y Mean age approximately 76 y for both groups

Elective major abdominal (cancer) surgery Randomly assigned to

General / epidural anesthesia + postoperative epidural analgesia (local anesthetic + opioid) (n = 35)

General anesthesia + postoperative iv PCA (morphine) (n = 35) Endpoints

Pain intensity (VAS score) Mental status Patients satisfaction score Cardiac function Respiratory function Gastrointestinal function

Mann et al., Anesthesiology (2000); 92: 433-41

Pain relief was significantly better during 5 postoperative days in the epidural group, at rest and after coughing

Mental status scores were significantly better on postoperative days 4 and 5 in the epidural group (although, for each day only once out of two daily measurements)

The incidence of postoperative delirium was similar in both groups

Bowel function recovered faster in the epidural group Cardiopulmonary complications were similar in both groups

Mann et al., Anesthesiology (2000); 92: 433-41


Recently: Positive effect on long-term survival after cancer surgery?

Intraoperative general anesthesia + epidural anesthesia/analgesia


Recently: Positive effect on long-term survival after cancer surgery?

Side effects and complications Pruritus (epidural opioids) Urinary retention Low incidence of severe complications if contraindications are

respected Epidural hematoma Epidural abcess Neurologic injury (temporary, permanent)

MAS and EAA:Conclusions (1)

EAA for MAS consistently results in superior postoperative analgesia and improved recovery of bowel function

There is insufficient evidence that EAA for MAS affects mortality and major postoperative morbidity

EAA techniques are associated with minor side effects

Major complications due to EAA are rare if contraindications are heeded


Patient safety Mortality Major morbidity

Patient satisfaction Minor morbidity Side effects

Economic benefits

MAS and EAA:Conclusions (2)

Epidural anesthesia/analgesia for major abdominal surgery has is important in terms of patient-oriented outcomes and patient satisfaction

However, since an effect of epidural anesthesia/analgesia on mortality and major morbidity after major abdominal surgery remains unproven, the prevention of severe complications of neuraxial techniques is absolutely indicated

Is mild hypothermia clinically important?

Anesthesia and Hypothermia

Anesthesia-related thermoregulatory impairment Initially: internal core to peripheral redistribution of body heat Subsequently: heat loss exceeding metabolic heat production

Inadvertent perioperative hypothermia: core body temperature ≤ 36.0 °C

Incidence ≈ 20 %? Poor compliance to guidelines

Mistaken belief that forced air warming increases risk of infection Surgeons’ complaint of discomfort Inconsistent monitoring Inadequate knowledge of the consequences

Hypothermia and Perioperative Complications (1)

Increased blood loss and transfusion requirement Coagulopathy

Impaired platelet function Impaired function of enzymes of the coagulation cascade

Rajagopalan et al., Anesthesiology (2008); 108: 71-7

15 prospective RCTs (1966-2006) comparing normothermic patients with patients who had mild (34-36 °C) intraoperative hypothermia

14 reporting blood loss (1219 patients) 10 reporting transfusion requirements (985 patients)

Median (quartiles) of the mean temperatures reported in the blood loss trials

Normothermic: 36.6 °C (36.4 °C, 36.7 °C) Hypothermic: 35.6 °C (35.4 °C, 35.8 °C)

Significant variability among studies Blood loss: estimated 16 % lower average blood loss for

normothermic vs hypothermic patients (P = 0.009) Transfusion: normothermia is associated with 22 % less risk

of transfusion than hypothermia (P = 0.027)


Blood loss: estimated 16 % lower average for normothermic vs hypothermic patients


Transfusion: normothermia is associated with 22 % less risk than hypothermia


Increased blood loss and transfusion requirement Surgical wound infection

Vasoconstriction with impaired subcutaneous oxygen tension Neutrophils: impaired oxidative killing Reduced deposition of collagen

Impaired immune function

Double blinded RCT 200 patients Colorectal surgery

All patients: cefamandole, metronidazole Randomy assigned to

Hypothermia: routine intraoperative thermal care (n = 96) Normothermia: additional warming (n = 104)

Warmed fluids, farced air warming Daily wound inspection by surgeons until discharge and

after 2 weeks Culture-positive pus = infected

Patient characteristics were similar for the 2 groups

Kurz et al., NEJM (1996); 334: 1209-15

Kurz et al., NEJM (1996); 334: 1209-15

Kurz et al., NEJM (1996); 334: 1209-15

Intraoperative core temperatures approximately 2 °C below normal during colorectal surgery: triple the incidence of wound infection and prolong hospitalization by about 20 %.

X 3

+ 20 %


Cardiac complications Prolonged recovery Prolonged hospitalization Negative nitrogen balance Patient discomfort

Perioperative Maintenance of Normothermia Reduces the Incidence of Morbid Cardiac Events.

Frank et al., JAMA (1997); 277: 1127-34

RCT comparing routine thermal care (hypothermia) to additional warming care (normothermia)

300 patients with coronary artery disease or at high risk for coronary disease

Surgery: abdominal, thoracic, or vascular Cardiac events

Unstable angina Ischemia Cardiac arrest Myocardial infarction

Hypothermia was an independent predictor of morbid cardiac events: there was approxiamtely 55 % reduction in risk if normothermia was maintained

Postoperative ventricular tachycardia occurred less frequently in the normothermic group than in the hypothermic group

Frank et al., JAMA (1997); 277: 1127-34

Normothermia Hypothermia P-value

Core temperature after surgery (mean)

36.7 35.4 < 0.001

Incidence of morbid cardiac events

1.4 % 6.3 % 0.02

Postoperative ventricular tachycardia

2.4 % 7.9 % 0.04

Mild Intraoperative Hypothermia: Conclusion

Even mild inadvertent intraoperative hypothermiashould be avoided

Intraoperative supplemental oxygen administration:

Is there an optimal concentration?

Perioperative Supplemental Oxygen Concentration

Preoxygenation FiO2 1.0: development of (mild) atelectasis is a consistent

finding And we do this every day…

FiO2 0.8: minimal atelectasis Significantly faster desaturation compared with 100 % O2

Intraoperative inspired oxygen concentration Postoperative supplemental oxygen administration

Does every patient need it? How much? For how long? Hemodynamic benefits? Clinical significance?

Edmark et al., Anesthsiology (2003); 98: 28-33

Intraoperative High FiO2: Risks (1)

Resorption atelectasis Airway obstruction: absorption of trapped gas

Even after a few breaths of 100 % oxygen Reversible with positive pressure

No airway obstruction: if VA/Q is low, absorption of oxygen into the capillaries may exceeding the inspired gas flow

After longer duration of exposure?

Benoit et al., Anesth Analg (2002); 95: 1777-81

Intraoperative High FiO2: Risks (2)

Ischemic reperfusion injury Free radical damage Mainly animal studies, no large RCT in humans

Oxygen toxicity Prolonged exposure

FiO2 0.8 < 24 h: safe?

FiO2 1.0 at 1 atm for 6 d: irreversible damage

Pulmonary intersitital edema Pulmonary fibrosis

Intraoperative High FiO2: Benefits (1)

Reduced incidence of wound infection? Yes

Greif et al., N Engl J Med (2000); 342: 161-7 Sessler and Akca, Clin Infect Dis (2002); 35: 1397-404 Belda et al., JAMA (2005); 294; 2035-2042

No Pryor et al., JAMA (2004); 291: 79-87

(Retrospective, underpowered?, treatment groups were not homogenous, variables possibly increasinf infection risk were not controlled)

Surgical Wound Infection and Oxygen

Wounds are hypoxic compared to normal tissue due to a disrupted vascular supply (injury, vessel thrombosis)

Resistance to infection depends on wound PO2

Oxidative killing by neutrophiles Wound tissue PO2 predicts the risk of wound infection in

surgical patients Oxygen is important for tissue repair and wound healing

Collagen synthesis is PO2-dependent Oxygen is a cell signal interacting with growth factors

Greif et al., NEJM (2000); 342: 161-7

Intraoperative High FiO2: Benefits (2)

Reduced incidence of nausea and vomiting? Controversial clinical data

Yes Greif et al., Anesthesiology (1999); 91: 1246-52 (colorectal surgery) Goll et al., Anesth Analg (2001); 92: 112-17 (gynecological laparoscopy)

No Purhonen et al., Anesth Analg (2003); 96: 91-6 (ambulatory gynecological

laparoscopy) Joris et al., Br J Anaesth (2003); 91: 857-61 (thyroidectomy) Treschan et al., Anesthesiology (2005); 103: 6-10

Gastrointestinal ischemia (abdominal surgery) Dopamine release from carotid bodies is inversely related to

blood PO2

?Is there an optimal intraoperative FiO2?

Intraoperative FiO2 0.8 may reduce the incidence of postoperative wound infections

High intraoperative FiO2 is not a reliable treatment to reduce postoperative nausea and vomiting

The risks of intraoperative high inspired oxygen concentrations are not clear

We need data evaluating more moderate oxygen concentrations

Optimal Intraoperative FiO2: Conclusions

anesthesie en outcome na abdominale heelkunde

Health & Medicine

reduction of major morbidityby

major abdominalsurgery

br j surg

br med j

j clinanesth

major morbiditylack

analgesia eaa

systemicopioids11 trials