•  New tools for airway management

•  New minimally invasive hemodynamic monitoring and goal directed fluid therapy

•  Oxygenation and ventilation monitoring

•  Closed loop drug delivery

•  Older and sicker patients undergoing extensive surgical procedures

•  Emphasis on shorter hospital stay and fast-track surgery

•  Realization that intraoperative management influences postoperative outcome

Wilmore and Kehlet: BMJ 2000; 322: 473-6

•  New airway management tools

•  CNS monitoring

•  Oxygenation (SaO2) and ventilation (CO2) monitoring

•  Non-invasive cardiac output monitoring

•  Patient and fluid warming systems

•  Anesthesia machine – digital ventilation

•  MRI compatibility machine and monitoring devices

•  Hazards air handling, gas evaluation, gas piping systems

•  Automated anesthesia record keeping system

•  Communication technology •  Home infusion pumps and acute management

systems

Intubation

Mask Ventilation

Supraglottic Devices

Airway Management

Laryngeal Mask Airway (LMA)

•  Improves visualization of larynx •  Difficulty in tracheal intubation

despite excellent visualization of the larynx

•  Need to modify laryngoscopy technique –  Laryngoscope blade placed in midline –  Drop down the larynx such that the

laryngeal view is not complete –  Use bougie or fiberscope

Video Laryngoscopes: Limitations

Right palatopharyngeal fold Can J Anaesth 2007; 54:322-324

•  Anterior tonsilar perforation

AnesthAnalg 2007;104 1610-11

•  Right palatopharyngeal arch perforation Can J Anaesth 2007;54:54-7

•  Soft palate injury

J Clin Anesth 2007;19:619-21

Can J Anaesth 2007;54:588-9

Anesth Analg 2007;104;1609-10

•  Pharyngeal injury

Otol Head Neck Surg 2007;37:175-6

•  Versatile •  Battery operated •  Combination with video

laryngoscopes

Limitations •  Fragile •  Hard to clean

•  Preoperative fasting

•  Bowel preparation

•  Intraoperative losses –  Blood loss

–  Evaporation

–  Third spacing

•  General and regional anesthesia –  Vasodilatation

Joshi GP: Anesth Analg 2005; 101: 601-5

•  We have become desensitized to administration of high fluid volumes (5-6 liters for major surgical procedures) –  Kudsk: Ann Surg 2003; 238: 649-50

•  Patients typically gain 5 kg of body weight after major surgical procedure –  Lobo et al: Best Prac Res Anaesthesiol 2006;

20:439-55

•  Perioperative hypervolemia increases postoperative morbidity and mortality

•  Holte et al: Br J Anaesth 2002; 89: 622-32

•  Perioperative fluid overload is a contributory cause of postoperative complications and death

–  National Confidential Enquiry into Perioperative Death (http://www.ncepod.org.uk)

•  Individualized fluid therapy that adapts to changing patient needs during the periop period

•  Prevents subtle hypovolemia and hypervolemia that might lead to organ dysfunction, increase perioperative complications, and delay recovery

•  Goal: maximize tissue O2 delivery with minimal cardiac O2 consumption –  Stroke volume most commonly used –  Optimal goal remains to be determined

•  Fluid challenges to optimize dynamic (flow-related) goals

•  Fluid bolus increases stroke volume in hypovolemic state

•  In absence of hypovolemia: no change in stroke volume with fluid bolus

<10% Change

LV End Diastolic Volume

Stro

ke V

olum

e

Starling Curve

•  Heart rate

•  Mean arterial blood pressure

•  Central venous pressure

–  (CVP or PAWP)

•  Stroke volume and cardiac

output derived from arterial

wave analysis (pulse contour,

pulse power analysis, non-

invasive finger pressure, and

plethysmography)

t [s]

P [mm Hg]

•  Mechanical ventilation induced variations –  Pulse-pressure –  Systolic blood pressure –  Stroke volume

•  Predictors of fluid responsiveness and need for fluid administration

Michard: Anesthesiology 2005; 103: 419-28; Pinsky: Crit Care 2006; 10: 117

Monitoing Brain Perfusion: Cerebral Oximetry

•  Measure of tissue perfusion and oxygen delivery

•  Can be used as a end-point for goal directed fluid therapy

•  With US population aging and becoming obese •  70-80% of patients with OSA are undiagnosed •  Increased postoperative respiratory complications

•  Respiratory depression rates are between 0.19% and!5.2%

–  Reported rates fluctuate due to inconsistencies in!definition

–  Commonly defined by decreases in O2 saturation –  Definitions do not consider hypoventilation

resulting from shallow breathing or ineffective respirations resulting from sedation

–  Rates also may be limited to instances where intervention (i.e., naloxone) is required

Hagle ME, et al. Orthopaedic Nursing. 2004;23:18-27.

Monitoring Ventilation

•  End-tidal CO2 waveform –  Presence of CO2 confirms

airway patency

•  Acoustic probes –  Measures air movement and

confirms airway patency

•  Bioimpedence technology –  Measures respiratory efforts

and provides respiratory rate –  No information airway patency

Awake

Light/Moderate Sedation

General Anesthesia

Cortical Silence

100

70

60

40

0

! Target-controlled infusion (TCI) drug delivery –  Drugs delivered based on PK models

! Computer-assisted personalized sedation (CAPS) –  Sedasys™, McDreamy –  TCI + monitoring + smart alarm

system that restricts drug delivery ! Pharmacodynamic drug delivery

–  McSleepy –  BIS-controlled propofol infusion

Hemmerling T: Curr Opin Anaesthesiol 2009; 22: 757-63

Hemmerling T: Curr Opin Anaesthesiol 2009; 22: 757-63 Hemmerling T: Curr Opin Anaesthesiol 2009; 22: 757-63

Hemmerling T: Curr Opin Anaesthesiol 2009; 22: 757-63 Daniels J, et al: Curr Opin Anaesthesiol 2009; 22: 775-81

Daniels J, et al: Curr Opin Anaesthesiol 2009; 22: 775-81 Allows monitor the patient, surgical field and the patient's vital signs simultaneously without having to turn around to scan the monitors Liu D et al: Curr Opin Anaesthesiol 2009; 22: 796-803

The Microvision Nomad ND2000 (Bothell, WA) head-mounted display Liu D et al: Curr Opin Anaesthesiol 2009; 22: 796-803

•  Numerous new technology are being introduced

•  Adopting new technology WILL increase healthcare costs!

•  Before any new technology is adopted for routine clinical practice, they MUST prove improved perioperative outcome and facilitate recovery Modern Practice

Traditional Practice

Max Plank: JAMA 1999; 282: 1606