laparoscopy & its ergonomics by dr.mohammad zarin
TRANSCRIPT
Ergonomics & Physiology In Laparoscopic Surgery
Dr.Mohammad ZarinMBBS, FCPS, MRCS, FMASAssociate Professor, SEWKhyber Teaching Hospital
Outline of Presentation
• Ergonomics• Physiology• Instruments
RAAS
ERGONOMICS
2 D ImageNo depth PerceptionNo tactile feedback
Counter-intuitiveLimited movements
Magnification
Open Surgeon Vs Lap SurgeonHow do they differ?!
Open Surgeon• Fast• Hand is as good as eyes• Dissection precedes• Ergonomics: Optional
Laparoscopic Surgeon• Slow and steady• Stop when you don’t see• Haemostasis precedes• Ergonomics: Vital
To be an efficient Surgeon…
• Equipments• Environment
Concentrate on
PATIENT POSITION
Produce gravitational displacement of viscera away from surgical site.
Trendelenberg Rev Trendelenberg 15-20˚ head down 20-30˚ head up Endobronchial intubation
Predisposition to DVT
Patient positioning
Ergonomics
• Straight Line principle• Triangulation• Manipulation angle• Elevation angle• Low lying table• Gaze down view
Straight Line Principle
Surgeon
PathologyMonitor
Visual Axis and Motor Axis
Co Axial alignment
Base Ball Diamond Concept& TriangulationMonitor
S
C
R
L
P
Manipulation angle
Azimuth Angle Manipulation Angle
30-45 degree60-90 degree
Elevation angle
Ideal angles!
1. Manipulatation angle: 60 degree2. Azimuth angle: Equal/30 degree each3. Elevation angle: 60 degree
Ergonomics of Hand Instruments
• Tip– Range of movements
• Conventional Vs Robotic instrument: 4: 7
Ergonomics of Hand Instruments
• Tip– Range of movements
• Conventional Vs Robotic instrument
• Length of the shaft
Fulcrum Effect of Hand Instruments
1: 1
Ergonomics of Port Placement
Ergonomics of Hand Instruments
• Tip– Range of movements
• Conventional Vs Robotic instrument– Force transmission
• Length of the shaft• Handle design
Ergonomic handles…
Surgeon’s Stance
Ideal relaxed stature Tiring
Ideal Relaxed Position
-straight head, in the axis of the trunk, without rotation or extension of the cervical spine;- shoulders in a relaxed and neutral position;- arms alongside the body- elbows bent to 70 to 90 degrees- forearms in an horizontal or slightly descending axis- -hands pronated (physiological resting position);- hands and fingers lightly grip the handles/handpiece
•Waist line table•Gaze down view of monitor•Straight line principle•Triangulation
PHYSIOLOGICAL EFFECTS OF LAPAROSCOPY
Can be: Mechanical Metabolic
On • Cardiovascular• Pulmonary• Gastrointestinal• Renal• Peripheral vascular
Cardiovascular Effects:
↑ IAP
↓ CO
↓ VR
↓ SV
↑ Afterload
↑ MAP
HRx =
↑ Vasopressin & Catecholamines
↑ CO2
↑ CVP ↑ PCWP ↑ SVR
↓ VR ↓ LVEDV
Cardiovascular Effects:
• Cardiac Output– Variation between studies– < 30% decrease when observed– On insufflation; ∞ ↑ in I.A.P; transient
• generally noted in:– ASA Class III/IV– hypovolemic patients– PP > 15 mm Hg– reverse Trendellenberg position
Respiratory Effects:↑ IAP
↑ cephalad shift diaphragm
paradoxic diaphragm motion
↑ ITP
↓ FRC
↑ RR
↑ CO2
↑ Ve & work of breathing
↓chest wall compliance
Hypercapnia
↑ PAWP
+
Alveolar Collapse
↓ TV
Respiratory Complications:• Pneumothorax / Pneumomediastinum /
Pneumopericardium– 2° to diffusion of gas from
pneumoperitoneum• Accidental diaphragm injury / pre-existing diaphragmatic
defect– 2° to rupture of blebs with ↑ PAWP
• Gas Embolism– 2° to vascular injury
• trocar / needle insertion on insufflation / intra-op vessel injury
Gastrointestinal effects:
↑ I.A.P.
↓ Mesenteric & celiac flow↓ hepatic
artery flow
↓ hepatic perfusion
↓ perfusion intestines &
stomach
↓ Portal flow
↑ LFTs↓ intestinal & gastric pH
Renal Effects:
↑ I.A.P.
↓ GFR↓ERPF
↓ U/O
RAAS
↑ CO2
Renal Effects:
• U/O return to baseline within hours• No long-term change in GFR• No change in Cr, BUN
Peripheral Vascular Effects:
↑ I.A.P.
Reverse Trendellenberg
Venous stasis
↓ VR
↑ Risk DVT?
Peripheral Vascular Effects:
• Incidence of DVT, PE generally lower post laparoscopic procedures– Secondary to improved prophylaxis?– Risk increased with longer procedures and
reverse Trendellenberg
Laparoscopic Instruments
• Hand instruments