1. Humidification in Laparoscopic Colonic Surgery
6/2/ :46 AM
Humidification in Laparoscopic Colonic Surgery
Tarik Sammour
Arman Kahokehr
Mike Hulme-Moir
Julian Hayes
Andrew G Hill
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2. Normal peritoneal mesothelium Close-up 30min of pneumoperitoneum
24h later
12h later
Caused by desiccation
from cold, dry gas.
Normal: Intact mesothelial surface and indistinct cell borders.
2h: Mesothelial cells bulged and retracted
Closeup: Underlying basal lamina visible
12 h: Cells are largely denuded
24h: Macrophages and lymphocytes

3. Warming and Humidification
Proposed Solution:
Warming and Humidification
of laparoscopic gas
Water chamber
4-in-1 probe
Heated Tube
Humidifier

4. Meta-analysis (Sammour et al, Br J Surg 2008)
7 RCT’s: Upper GI / Gynae
Reduction in post-op pain
Reduction in post-op opiate use
Limitations
Poor quality studies
Unblinded studies
Did not standardise Bair Hugger use
No studies in prolonged laparoscopy

5. Hypothesis In laparoscopic colectomy,
warming and humidification of insufflation gas will reduce post-op pain
by decreasing peritoneal desiccation.

6. Methods - Patients
All patients > 15 yrs undergoing laparoscopic colon resection in
three Auckland hospitals
Exclusions:
Rectal lesions (below 15cm on colonoscopy)
Patient requiring stoma
Hand-assisted resections
ASA > 4
Steroid dependent

7. Methods - Groups Intervention Control Standardized protocol
Humidified and warmed CO2
Control
Standard CO2
Standardized protocol
Room temp 19 °C
Bair hugger in all cases
Standardised analgesia
Randomization
Computer generated random numbers
Stratified by site
Opaque envelopes opened in OT
Premed: Paracetamol 1g
Dexamethasone 8mg
Intraop: Morph / Fentanyl (wt based)
Postop: Morph / Fentanyl PCA

8. Methods - Blinding Patient, surgical team, investigators blind
Humidifier always attached
Covered with specially designed PVC cover
Single unblinded research assistant
Data analysis also blinded

9. Methods - Power Morphine Equivalent Daily Dose (MEDD)
Mean from 3 published RCTs = mg
Conservative estimate = mg
20% reduction clinically significant
Powered for: α 0.05 and β 0.80
Sample size required = 74 patients

10. Outcomes Morphine Equivalent Daily Dose (MEDD)
Pain Visual Analogue Score (VAS)
Intra-op core temperature
Camera fogging
Plasma & peritoneal cytokine response
Post-op recovery
PACU
Day 1
Day 2
Day 3
TOTAL 2h 4h 8h
12h
Day 1
Day 2
Day 3
Day 7
Day 14
Day 30
Day 60
Pain was measured using visual analogue scores at rest, moving, and coughing.
Intraop temperature was measured at 15 minutes intervals using a nasopharyngeal probe.
At the conclusion of surgery, the primary surgeon was asked to rate camera fogging on a Likert scale (1 perfect image, 10 very poor quality image).
Peritoneal and plasma cytokine concentrations were measured at 20 hours postoperatively.
Postop recovery was measured using defined discharge and complication criteria, and the Surgical Recovery Score.

11. Patients assessed for eligibility Did not meet incl criteria
April 2008 – June 2009
Patients assessed for eligibility
n = 111
Did not meet incl criteria
n = 29
Randomised
n = 82
Intervention
n = 41
Control
n = 41
Analysed n = 35
Excluded n = 6
Rectal Ca intraop n = 2
No colon resected n = 2
Un-blinding n = 1
Stoma n = 1
Analysed n = 39
Excluded n = 2
No colon resected n = 1
Anaphylaxis n = 1

12. No Difference Baseline Humidified (n = 35) Control (n = 39) P Value
Age (median, IQR)
71 (29)
69 (22)
0.959
Sex
Male
Female
15 (42.9%)
20 (57.1%)
16 (41.0%)
23 (59.0%)
1.000
BMI (mean, SD)
26.5 (4.8)
25.5 (5.4)
0.401
ASA score I II
III
6 (17.1%)
21 (60.0%)
8 (22.9%)
3 (7.7%)
13 (33.3%)
0.355
CR-POSSUM (median, IQR)
17 (5)
19 (5)
0.178
Previous surgery
0.475
Operation
Ileocolic resection
R hemicolectomy
Extended R hemicolectomy
Transverse colectomy
L hemicolectomy
Sigmoid colectomy
High anterior resection
5 (14.3%)
14 (40.0%)
1 (2.9%)
2 (5.7%)
7 (20.0%)
0 (0%)
11 (28.2%)
1 (2.6%)
6 (15.4%)
2 (5.1%)
0.073
No Difference
Baseline

13. Intra-operative Humidified (n = 35) Control (n = 39) P Value
Operating Time (mean, SD)
Total operating time
Pneumoperitoneum time
176.3 (48.8)
105.1 (39.0)
184.7 (57.5)
116.9 (55.0)
0.504
0.295
Volume CO2 used (mean, SD)
113.9 (110.1)
178.4 (170.4)
0.057
Conversion to laparotomy
Converted
Not converted
2 (5.7%)
33 (94.3%)
6 (15.4%)
33 (84.6%)
0.267
Total wound size (median, IQR)
10.0 (5.0)
11.3 (6.0)
0.451
Camera fogging score (median, IQR)
4 (5)
2 (3)
0.040
Intra-operative

14. P = 0.324

15. No Difference Opiate Use Humidified (n = 35) Control (n = 39) P Value
MEDD use (median, IQR)
Intra-op
PACU
Day 0
Day 1
Day 2
Day 3
Total
35.0 (17.5)
10.0 (16.0)
12.0 (22.0)
22.0 (28.5)
16.0 (21.5)
7.5 (21.0)
77.0 (95.0)
35.0 (26.0)
8.0 (18.0)
9.0 (17.0)
36.0 (41.0)
20.0 (32.0)
10.0 (21.0)
94.4 (107.0)
0.728
0.783
0.516
0.344
0.156
0.364
0.414
No Difference
Opiate Use

16. P = 0.010
Rest
P = 0.018
Pain by VAS
Moving
P = 0.006
Coughing

17. No Difference Recovery Humidified (n = 35) Control (n = 39) P Value
Discharge (median, IQR)
Met discharge criteria
Actual discharge day
Total day stay
3 (3)
5 (5)
7 (7)
3 (2)
5 (6)
5 (7)
0.755
0.750
0.873
Complication Grade I II
III IV
1 (5.3%)
15 (78.9%)
3 (15.8%)
0 (0%)
13 (68.4%)
2 (10.5%)
0.543
Surgical Recovery Score
Baseline
Day 1
Day 3
Day 7
Day 30
Day 60
72.9 (13.7)
52.2 (21.0)
54.3 (14.3)
58.8 (14.5)
67.4 (15.6)
74.7 (13.5)
72.9 (14.4)
52.3 (16.1)
50.6 (18.5)
52.2 (15.1)
69.5 (14.6)
72.4 (16.4)
0.977
0.986
0.381
0.077
0.598
0.580
No Difference
Recovery
Readmission: 23% vs 8%, P = 0.102
3 leaks in control group, 2 in study group

18. Cytokines
P = 0.50
P = 0.70
Peritoneal
Plasma

19. Conclusion
Warming and humidification of insufflation CO2 does not reduce pain or peritoneal inflammation after laparoscopic colonic surgery.