Intraoperative Evaluation of Laparoscopic Insufflation Technique for Quality Control in the OR

Abstract

With increasing technology and computerized systems in the OR, the physician's responsibility is growing. For intraoperative evaluation of insufflation techniques, a data acquisition model for quality control study of potential insufflation problems is necessary.
A computer-based, online data acquisition model was designed with a Pentium notebook, PCMCIA data acquisition board PCI-460-P1 and a Visual Designer 3.0 measurement program (both Intelligent Instrumentation, Inc., Tucson, AZ), temperature meters Therm 2280-1 and 2283-2 (Ahlborn, Holzkirchen, Germany) and temperature probes 401 AC and 402 AC (YSI, Inc., Yellow Springs, OH) and T-430-2R (Ahlborn, Holzkirchen, Germany). Gas flow was measured with laminar flow element LFE 1 and flow meters Digima premo 720 (both Special Instruments, Noerdlingen, Germany). During 73 standard laparoscopic procedures, gas flow (L/min) in the insufflation hose, pressure (mm Hg) in the hose and abdomen as well as temperature (degrees C) in the hose, abdomen and rectum were measured continuously at 3 Hz rate.
Actual values measured show a wide range often not identical with insufflator presetting. Pressure in the abdomen is usually less than hose pressure. Intra-abdominal pressure peaks (< or = 50 mm Hg) occurred during insufficient anesthesia, while leaning on the abdomen, during trocar insertion and other manipulation. Blood-irrigation fluids found in the hose (n=3/73) can lead to bacterial contamination. Negative pressure (-50 mm Hg) was measured due to Endobag removal. Negative flow (< or = 15 L/min) was caused by pressure on the abdomen, insufflator regulation and an empty CO2 gas tank. Gas temperature in the hose equals room temperature but can decrease in the abdomen to 27.7 degrees C due to high gas flow, large amounts of gas used and prolonged insufflation. Further insufflation-related problems were documented.
This computer-based measurement model proved to be useful for quality control study in the OR. Results demonstrate the need for intraoperative evaluation of insufflation techniques for laparoscopy. Although no obvious complication related to insufflation problems occurred, some findings potentially question patient security.

Full text

Intraoperative Evaluation of Laparoscopic Insufflation
Technique for Quality Control in the OR
JSLS (2000)4:189-195 189
ABSTRACT
Objective: With increasing technology and computer-
ized systems in the OR, the physician’s responsibility is
growing. For intraoperative evaluation of insufflation
techniques, a data acquisition model for quality control
study of potential insufflation problems is necessary.
Methods: A computer-based, online data acquisition
model was designed with a Pentium notebook, PCMCIA
data acquisition board PCI-460-P1 and a Visual Designer
3.0 measurement program (both Intelligent
Instrumentation, Inc., Tucson, AZ), temperature meters
Therm 2280-1 and 2283-2 (Ahlborn, Holzkirchen,
Germany) and temperature probes 401 AC and 402 AC
(YSI, Inc., Yellow Springs, OH) and T-430-2R (Ahlborn,
Holzkirchen, Germany). Gas flow was measured with
laminar flow element LFE 1 and flow meters Digima
premo 720 (both Special Instruments, Noerdlingen,
Germany). During 73 standard laparoscopic procedures,
gas flow (L/min) in the insufflation hose, pressure (mm
Hg) in the hose and abdomen as well as temperature
(°C) in the hose, abdomen and rectum were measured
continuously at 3 Hz rate.
Results: Actual values measured show a wide range
often not identical with insufflator presetting. Pressure in
the abdomen is usually less than hose pressure. Intra-
abdominal pressure peaks (≤50 mm Hg) occurred during
insufficient anesthesia, while leaning on the abdomen,
during trocar insertion and other manipulation. Blood-
INTRODUCTION
A physician feels responsible for proper and secure func-
tion of all equipment that is used on or around the
patient. With increasing technology and computerized
systems in the OR, the surgeon’s responsibility is grow-
ing. One example is laparoscopy — a growing surgical
technique in which many different robotics, technical
and computerized devices are and will continue to be
used.
Many articles have been published about laparoscopic
procedures themselves within the last decade, but little is
known about insufflation technique. No objective data
regarding physical properties, the intraoperative function
and the interaction between patient and the insufflation
technique has been published; neither have any com-
prehensive models for its evaluation. The physician’s
general knowledge about basic physics is often not
enough to solve technical insufflation problems immedi-
ately. As surgeons, we rely and depend on manufactur-
ers and their promises about product properties. A com-
Department of Surgery, Fayette Medical Center (FMC), 1653 Temple Ave. N.,
Fayette, AL 35555, USA. Telephone: (205) 932-3879, Fax: (205) 932-5253, E-mail:
drmorjo@aol.com (Drs. Jacobs and Morrison Jr). Head of Department of Surgery at
Fayette Medical Center (Dr. Morrison Jr).
Frauenklinik (OB/GYN), Christian-Albrechts-University, Michaelisstr. 16, 24105 Kiel,
Germany. Telephone: +49-431-597-2100, Fax: +49-431-597-2146, E-mail: volkerja-
cobs@hotmail.com (Drs. Jacobs, Mundhenke, Golombeck and Jonat).
Director of Frauenklinik (OB/GYN), University of Kiel (Prof. Dr. Jonat).
Address reprint request to: Volker R. Jacobs, MD, Frauenklinik (OB/GYN),
Christian-Albrechts-University, Michaelisstr. 16, 24105 Kiel, Germany. Telephone:
+49-431-597-2100, Fax: +49-431-597-2146, E-mail: volkerjacobs@hotmail.com
© 2000 by JSLS, Journal of the Society of Laparoendoscopic Surgeons. Published by
the Society of Laparoendoscopic Surgeons, Inc.
Volker R. Jacobs, MD, John E. Morrison Jr, MD, Christoph Mundhenke, MD,
Kirstin Golombeck, MD, Walter Jonat, MD
irrigation fluids found in the hose (n=3/73) can lead to
bacterial contamination. Negative pressure (-50 mm Hg)
was measured due to Endobag removal. Negative flow
(≤15 L/min) was caused by pressure on the abdomen,
insufflator regulation and an empty CO
2
gas tank. Gas
temperature in the hose equals room temperature but
can decrease in the abdomen to 27.7°C due to high gas
flow, large amounts of gas used and prolonged insuffla-
tion. Further insufflation-related problems were docu-
mented.
Conclusions: This computer-based measurement
model proved to be useful for quality control study in the
OR. Results demonstrate the need for intraoperative
evaluation of insufflation techniques for laparoscopy.
Although no obvious complication related to insufflation
problems occurred, some findings potentially question
patient security.
Key Words: Laparoscopy, Insufflation technique, Data
acquisition, Quality control.
SCIENTIFIC PAPER

Intraoperative Evaluation of Laparoscopic Insufflation Technique for Quality Control in the OR, Jacobs VR et al.
prehensive, experimental laboratory study about insuffla-
tion properties of a variety of insufflation components
has shown remarkable differences in flow and resistance
values.
1
From this background rises the question: How
can the surgeon verify proper and secure function of the
insufflation technique?
We carried out an independent intraoperative study for
quality control to verify and compare function parameters
such as pressure, gas flow and temperature of the stan-
dard insufflation equipment used in pelviscopy and
laparoscopy and to better understand the physical back-
ground in which laparoscopy is performed. A computer-
based data acquisition model was developed with which
different physical parameters can be measured, docu-
mented and graphically displayed online.
METHODS
A Pentium notebook PC (Tecra 510 CDT; Toshiba, Inc.,
Irvine, CA) and a PCMCIA data acquisition board (PCI-
460-P1; Intelligent Instrumentation, Inc., Tucson, AZ)
were connected with different electronic meters for pres-
sure (Digima premo 720; Special Instruments,
Noerdlingen, Germany) and temperature (Therm 2280-1
for K probes (NiCr-Ni) and Therm 2283-2 for NTC
probes; Ahlborn, Holzkirchen, Germany). Different tem-
perature probes were used: NTC-probes 401 AC for
intra-abdominal temperature and 402 AC for rectal tem-
perature (YSI, Inc., Yellow Springs, OH); and K probe T-
430-2R for insufflation hose temperature (Ahlborn,
Holzkirchen, Germany). Gas flow was measured with a
laminar flow element (LFE 1; Special Instruments,
Figure 1. Visual Designer measurement diagram.
190 JSLS (2000)4:189-195

Noerdlingen, Germany). Measurement accuracy was +/-
0.1%. The measurement scheme was graphically created
with an adjustable, multiple-purpose measurement pro-
gram (Visual Designer 3.0; Intelligent Instrumentation,
Inc., Tucson, AZ; Figure 1) and transferred into the final
program. Results were displayed with a scientific graph-
ic program (Origin 4.1; Microcal, Inc., Northampton,
MA). Costs for this entire model were approximately
US$ 12,000.
Before the operation, the equipment (Figure 2) was
connected (as shown in Figure 3), and the rectal tem-
perature probe was introduced. The measurement pro-
gram was started and an intra-abdominal temperature
probe and pressure trocar were inserted. Over the entire
time of the procedure, parameters (gas flow in the hose;
pressure in the hose and abdomen; and temperature in
the hose, abdomen and rectum) were measured at 3 Hz
rate. The values were converted and stored on a hard
drive as ASCII files. A supervisor took additional infor-
mation intraoperatively so problems would be easier to
identify later on (Figure 4).
This computer model was used to evaluate different
insufflators: the Karl Storz Endoflator 26012CH (flow
max
20 L/min), Karl Storz Laparoflator 26012C (10 L/min),
Snowden & Pencer 89-8600 (15 L/min), BEI Medical
92000V (20 L/min) and Richard Wolf 2231 (15 L/min)
(Figure 5).
All intraoperative measurements were performed at the
Department of Surgery at Fayette Medical Center (FMC),
Fayette, Alabama, USA. Although nothing was changed
from standard laparoscopy for this experimental study,
all patients underwent a comprehensive informed con-
sent protocol, and their written consent was mandatory.
Institutional review board approval from FMC was
obtained.
For unaffected results, the use of resistance unrestricted
trocars (Storz HiCap 12-mm trocars: 8-mm insufflation
Figure 2. Computer model with all measurement devices. Left
bottom: Digima premo pressure meters; left top: Therm meters;
middle: PC card and data acquisition board; right bottom:
Laminar Flow Element; right top: Toshiba notebook.
Figure 4. OR setting at FMC with supervisor and PC- / equip-
ment table in front, patient on OR table in the background.
Figure 3. Measurement scheme.
JSLS (2000)4:189-195
191

Intraoperative Evaluation of Laparoscopic Insufflation Technique for Quality Control in the OR, Jacobs VR et al.
192 JSLS (2000)4:189-195
diameter at supply, without stopcock and no Luer lock
supply, Figure 6) for intra-abdominal pressure measure-
ment and free intra-abdominal placement of the gas tem-
perature probe is important (Figure 7).
This model was used on a variety of 73 consecutive stan-
dard laparoscopic procedures (eg, cholecystectomy, hys-
terectomy, hernia, Nissen fundoplication, etc). The
insufflator setting for all operations was 10 mm Hg nom-
inal pressure and flow
max
, O.R. temperature ~23°C. A
standard 10ft/3m insufflation hose with CO
2
filter was
used with all insufflators.
RESULTS
The measurements confirm that insufflators have differ-
ent insufflation and flow properties despite having the
same function. Pressure in the abdomen and insufflation
hose are not always identical: abdominal pressure (≤50
mm Hg) is usually less than pressure in the system (≤75
mm Hg). Gas flow efficiency of insufflators is limited
because high CO
2
gas flow (>10 L/min) is rarely reached
Figure 5. Insufflators evaluated (top to bottom): 1. Storz
Endoflator, 2. Storz Laparoflator, 3. Snowden & Pencer, 4. BEI
Medical, 5. Wolf.
Figure 6. Storz HiCap trocar with low flow resistance.
Figure 7. Free intra-abdominal placement of YSI temperature
probe tip.

due to high resistance, especially in disposable trocars.
The smaller the diameter at the insufflation supply, the
higher the trocar flow resistance. Pressure peaks (≤50
mm Hg) in the abdomen at nominal pressure (10 mm
Hg) occurred during trocar insertion and other abdomi-
nal manipulation — this can push gas or body fluids
toward the insufflator. Negative pressure (≤50 mm Hg)
and flow (≤-15 L/min) was measured during gallbladder
removal with an Endobag (Table 1). During 73 proce-
dures, body fluids were observed three times in the
insufflation hose due to over pressure in the abdomen,
insufficient relaxation and insufflator regulation with
negative gas flow causing potential bacterial contamina-
tion if no CO
2
gas filter was used.
CO
2
gas temperature in the hose equals room tempera-
ture. Changes in room temperature, depending on auto-
matic air conditioning, are reflected in gas temperature
fluctuation (Figure 8). Gas temperature in the abdomen
can decrease up to 8.3°C (from 36.0 to 27.7°C, average
32.7°C, Table 2), and body core temperature can drop
1.01°C even with aggressive use of body surface warm-
ing equipment, especially under high-flow use of large
amounts of gas and a prolonged period of insufflation.
Snowden & Pencer’s insufflator with internal gas heating
JSLS (2000)4:189-195 193
cannot heat up CO
2
to body temperature when it reach-
es the abdomen.
With this model, several intraoperative insufflation prob-
lems can be documented. An example is shown and
explained in Figure 8.
Figure 8 is a graphical documentation of typical intra-
operative insufflation problems: 1) start of insufflation;
2) trocar for abdominal pressure inserted; 3) abdominal
pressure peak 30 mm Hg, over pressure recognized by
Figure 8. Documentation of typical intraoperative insufflation
problems (BEI Medical insufflator and Ethicon Endopath 512 tro-
car).
Table 1.
Intraoperative activity affecting intra-abdominal pressure.
Type of Manipulation Pressure [mm Hg]
Trocar insertion +18-23
Intra-abdominal instruments manipulation +25
Physician leaning on abdomen +30
Insufficient patient relaxation +50
Insufflator switching on/off -1-2
Tissue removal with Endobag -50
Table 2.
Intraoperative intra-abdominal gas temperature minimum.
Intraoperative Patients (n) Insufflation Time
Intra-abdominal Gas Average (Range)
Temperature Minimum (°C) [min]
35.01 - 36.00 2 47.5 (42 - 53)
34.01 - 35.00 11 76.8 (21 - 159)
33.01 - 34.00 13 78.4 (22 - 152)
32.01 - 33.00 14 84.9 (27 - 182)
31.01 - 32.00 8 116.9 (65 - 186)
30.01 - 31.00 6 97.2 (30 - 269)
29.01 - 30.00 1 140
28.01 - 29.00 0 -
27.01 - 28.00 2 204.5 (21 - 323)
Avg. 32.7 (35.4 - 27.7) 5 7 91.5 (21 - 323)

Intraoperative Evaluation of Laparoscopic Insufflation Technique for Quality Control in the OR, Jacobs VR et al.
194 JSLS (2000)4:189-195
BEI Medical insufflator, automatically shut off, negative
gas flow –5 L/min; 4) not immediately recognized by
staff, loss of pneumoperitoneum; 5) same as number 3,
but now faster switched back on; 6) normal leakage reac-
tion during Mesh insertion; 7) stop-cock at Ethicon insuf-
flation trocar accidentally partly closed (ca. 30°); almost
no insufflation diameter left, loss of pneumoperitoneum
because of insufficient leakage reaction (flow limitation)
until finally realized; 8) normal leakage compensation; 9)
abdominal pressure trocar removed; 10) insufflation
stopped; 11) measurement artifacts through electro-coag-
ulation. Gas temperature curve in insufflation system is
reflecting air condition regulation fluctuation.
DISCUSSION
With this computer model, for the first time objective data
was measured about the real insufflation properties intra-
operatively. The actual physical values measured show a
wide range and are often not identical with the presetting
on the insufflator. Some, especially overpressure of up to
50 mm Hg in the abdomen, can potentially threaten
patient’s safety.
Several attempts to evaluate properties of insufflation
components have been made.
2-4
They all neglect the
effect of resistance on the performance of the entire
insufflation system, evaluate components separately
2,3
or
measured at very low flow rates of 1-2 l/min.
4
Previous
measurements show the insufflation system has to be
seen as a unit not as randomly combinable components.
1
Function also often depends on the interaction between
patient and equipment.
Though the results of our measurements are complex; the
following statements can be made: Insufflators showed
no significant difference regarding insufflation; insuffla-
tion problems described can occur with each of them.
For better insufflator flow efficiency, reusable trocars
should be used as they have, in general, less resistance
than disposable ones.
1
A filter in the insufflation system
is necessary in order to prevent potential contamination
of the insufflator. Insufflator-related pressure peaks of up
to 40 mm Hg found in an abdomen model box in the lab-
oratory study
1
could not be confirmed. But intra-abdom-
inal pressure peaks up to 50 mm Hg should be prevent-
ed by not leaning on the abdomen, providing sufficient
relaxation and being careful with intra-abdominal instru-
ment manipulation.
The significance of a decrease of intra-abdominal gas
temperature and its potential correction is controversial.
Internal heating of gas in the insufflator is inefficient
because CO
2
gas at the end of the insufflation hose is at
room temperature. Maintaining body temperature with
standard warming equipment, such as Bair Hugger
®
,
Blanketrol
®
, heating blankets, and fluid warmer, etcetera,
is possible and efficient, but take care of the problem
(hypothermia) after it occurs. Prolonged CO
2
pneu-
moperitoneum should be avoided in patients who could
be affected by high-flow of CO
2
gas and drop of abdom-
inal temperature. Recent studies seem to have solved the
problem with Insuflow
®
, a patient close-gas heating and
hydration device.
5
CONCLUSIONS
This computer-based measurement model has been
proven to be useful for quality control study, intraopera-
tive evaluation of the laparoscopic insufflation technique,
and can measure different physical parameters in the OR.
For other purposes, different devices can easily be sub-
stituted or added, and additional values can be calculat-
ed. Nevertheless, installation and adjustment of the PC
card as well as graphic design of a complex measure-
ment program can be challenging and difficult. Qualified
technical support is essential.
The results demonstrate the need for intraoperative eval-
uation of the insufflation technique for laparoscopy and
the need to document insufflation-related problems.
6,7
Improvements in insufflation equipment, design of resist-
ance optimized components, as well as standardization
and adjustment of all insufflation components is neces-
sary. Although no obvious complication related to insuf-
flation problems occurred during our measurements,
some results raise the potential of patient safety issues.
Therefore, further investigation of the interaction
between patient, physician and insufflation technique,
the physical effects and its influence on the patient’s
physiology is necessary.
References:
1. Jacobs VR. Experimentelle Untersuchung zu den
Insufflationseigenschaften verschiedener Veressnadeln, Trokare
und Insufflatoren zum Aufbau eines Pneumoperitoneums in der
Laparoskopie. [Experimental study on insufflation properties of
different Veress needles, trocars and insufflators to establish
pneumoperitoneum in laparoscopy.] Med Dissertation, 208
pages, University of Göttingen, Germany 1996.

JSLS (2000)4:189-195 195
7. Jacobs VR, Morrison JE Jr. Carbon dioxide gas heating in
laparoscopy: is it worth it? Intraoperative evaluation of insuffla-
tors with vs. without CO
2
gas heating device. Endo Expo ‘97,
6th Annual Meeting of the Society of Laparoendoscopic Surgeons
(SLS), Orlando, FL, USA, December 3-6, 1997. JSLS.
1997;1(4):369.
Acknowledgements: The authors thank administration, OR per-
sonnel and all staff at Fayette Medical Center, Fayette, Alabama,
for their comprehensive support and excellent cooperation dur-
ing this study.
Disclosure Statement: We received no grant or financial support
from any company for this study. We have no financial interest
to promote products mentioned here. This study is absolutely
independent and self-financed. We had no conflict of interests.
2. ECRI. Laparoscopic insufflators. Health Devices.
1992;21:143-179.
3. ECRI. High-Flow laparoscopic insufflators. Health Devices.
1995;24:252-285.
4. Borten M, Walsh AK, Friedman EA. Variations in gas flow
of laparoscopic insufflators. Obstet Gynecol. 1986;68:522-526.
5. Ott DE, Reich H, Love B, et al. Reduction of laparoscopic-
induced hypothermia, postoperative pain and recovery room
length of stay by pre-conditioning gas with the Insuflow
®
device:
a prospective randomized controlled multi-center study. JSLS.
1998;2(4):321-329.
6. Jacobs VR, Morrison JE Jr. The real intra-abdominal pressure
during laparoscopy: first intraoperative measurement model for
insufflator evaluation in laparoscopy. Endo Expo ‘97, 6th Annual
Meeting of the Society of Laparoendoscopic Surgeons (SLS),
Orlando, FL, USA, December 3-6, 1997. JSLS. 1997;1(4):368-369.