High-pressure laparoscopic entry does not adversely affect cardiopulmonary function in healthy women

Guideline No. 412: Laparoscopic Entry for Gynaecological Surgery

OBJECTIVE

To evaluate the benefits and risks of laparoscopic surgery and provide clinical direction on entry techniques, technologies, and their associated complications in gynaecological surgery.

TARGET POPULATION

All patients, including pregnant women and women with obesity, undergoing laparoscopic surgery for various gynaecological indications.

OPTIONS

The laparoscopic entry techniques and technologies reviewed in formulating this guideline included the closed (Veress needle-pneumoperitoneum-trocar) technique, direct trocar insertion, open (Hasson) technique, visual entry systems, and disposable shielded and radially expanding trocars.

OUTCOMES

Implementation of this guideline should optimize decision-making in the selection of entry technique for laparoscopic surgery.

EVIDENCE

We searched English-language articles from September 2005 to December 2019 in PubMed/MEDLINE, Embase, Science Direct, Scopus, and Cochrane Library using the following MeSH search terms alone or in combination: laparoscopic entry, laparoscopy access, pneumoperitoneum, Veress needle, open (Hasson), direct trocar, visual entry, shielded trocars, radially expanded trocars, and laparoscopic complications.

VALIDATION METHODS

The authors rated the quality of evidence and strength of recommendations using the Canadian Task Force on Preventive Health Care approach (Appendix A).

INTENDED AUDIENCE

Surgeons performing laparoscopic gynaecological surgery.

SUMMARY STATEMENTS

RECOMMENDATIONS.

No. 193-Laparoscopic Entry: A Review of Techniques, Technologies, and Complications

OBJECTIVE

To provide clinical direction, based on the best evidence available, on laparoscopic entry techniques and technologies and their associated complications.

OPTIONS

The laparoscopic entry techniques and technologies reviewed in formulating this guideline include the classic pneumoperitoneum (Veress/trocar), the open (Hasson), the direct trocar insertion, the use of disposable shielded trocars, radially expanding trocars, and visual entry systems.

OUTCOMES

Implementation of this guideline should optimize the decision-making process in choosing a particular technique to enter the abdomen during laparoscopy.

EVIDENCE

English-language articles from Medline, PubMed, and the Cochrane Database published before the end of September 2005 were searched, using the key words laparoscopic entry, laparoscopy access, pneumoperitoneum, Veress needle, open (Hasson), direct trocar, visual entry, shielded trocars, radially expanded trocars, and laparoscopic complications.

VALUES

The quality of evidence was rated using the criteria described in the Report of the Canadian Task Force on the Periodic Health Examination. RECOMMENDATIONS AND SUMMARY STATEMENT.

Laparoscopic entry techniques: What is the controversy?

OBJECTIVE

To review reported complications related to the different laparoscopic entry techniques in the human and veterinary literature and describe the benefits and limitations of each technique.

STUDY DESIGN

Literature review of 57 peer-reviewed articles.

METHODS

An electronic database search identified human and veterinary literature describing complications related to entry technique during laparoscopy.

RESULTS

Open- and closed-entry techniques may result in trauma of abdominal organs or vasculature. During laparoscopy in man, injury to bowel and major vasculature is reported in 0.02% and 0.04% of procedures with open- or closed-entry techniques, respectively. Designs of Veress needles and trocar cannula assemblies have been developed to improve ease and safety. Early complications, defined as those observed at the time of port entry into the abdominal cavity, result from the puncture of a blood vessel leading to substantial visible hemorrhage. Late complications are detected 24 or 48 hours after surgery and result from the puncture of a loop of intestine that was not detected at the time of initial surgery. The major reasons for iatrogenic trauma in man are related to anatomical factors and the presence of adhesions. No explanation for cause of complications was identified for animals.

CONCLUSION

There is no consensus in the human or veterinary literature about the best entry technique for laparoscopy. The rate of complications related to entry technique in small animals is not known because the data are underreported.

CLINICAL SIGNIFICANCE

Complications related to entry techniques are expected in both man and animals. Improvements in techniques and equipment design are being developed to minimize risk.

A prospective randomized trial of postoperative pain following different insufflation pressures during gynecologic laparoscopy

OBJECTIVE

To determine the effects of different intra-abdominal pressure values on visceral pain following gynecologic laparoscopic surgery in the Trendelenburg position.

STUDY DESIGN

This randomized, controlled prospective trial was conducted at a tertiary education hospital and included 150 patients who underwent gynecologic laparoscopy with different abdominal insufflation pressures. There were 54 patients in the 8 mmHg low pressure group (LPG), 45 in the 12 mmHg standard pressure group (SPG), and 51 in the 15 mmHg high pressure group (HPG). We assessed mean age, body mass index (BMI), duration of surgery, analgesic consumption, length of hospital stay, amount of CO2 expended and volume of hemorrhage. Visceral pain and referred visceral pain were assessed 6, 12, and 24 h postoperatively using a visual analog scale (VAS).

RESULTS

There was no significant difference in age, BMI, analgesic consumption or length of hospital stay among groups. The mean operative time and total CO2 expended during surgery were higher in the LPG compared with the SPG and HPG. The mean intensity of postoperative pain assessed by the VAS score at 6 and 12 h was less in the LPG than in the SPG and HPG and was reduced significantly at 12 h. VAS scores at 24 h in the LPG and SPG were lower than in the HPG.

CONCLUSION

Pain is reduced by low insufflation pressure compared with standard and high insufflation pressure following gynecologic laparoscopic surgery in the Trendelenburg position. However, low insufflation pressure may result in longer operation times and increased hemorrhage.

Effects of elevated artificial pneumoperitoneum pressure on invasive blood pressure and levels of blood gases

BACKGROUND AND OBJECTIVE

to evaluate the clinical, hemodynamic, gas analysis and metabolic repercussions of high transient pressures of pneumoperitoneum for a short period of time to ensure greater security for introduction of the first trocar.

METHODS

sixty-seven patients undergoing laparoscopic procedures were studied and randomly distributed in P12 group: n=30 (intraperitoneal pressure [IPP] 12mmHg) and P20 group: n=37 (IPP of 20mmHg). Mean arterial pressure (MAP) was evaluated by catheterization of the radial artery; and through gas analysis, pH, partial pressure of oxygen (PaO2), partial pressure of CO2 (PaCO2), bicarbonate (HCO3) and alkalinity (BE) were evaluated. These parameters were measured in both groups at time zero before pneumoperitoneum (TP0); at time 1 (TP1) when IPP reaches 12mmHg in both groups; at time 2 (TP2) after five min with IPP=12mmHg in P12 and after 5min with IPP=20mmHg at P20; and at time 3 (TP3) after 10min with IPP=12mmHg in P12 and with return of IPP from 20 to 12mmHg, starting 10min after TP1 in P20. Different values from those considered normal for all parameters assessed, or the appearance of atypical organic phenomena, were considered as clinical changes.

RESULTS

there were statistically significant differences in P20 group in MAP, pH, HCO3 and BE, but within normal limits. No clinical and pathological changes were observed.

CONCLUSIONS

high and transient intra-abdominal pressure causes changes in MAP, pH, HCO3 and BE, but without any clinical impact on the patient.

Effects of elevated artificial pneumoperitoneum pressure on invasive blood pressure and levels of blood gases

BACKGROUND AND OBJECTIVE

to evaluate the clinical, hemodynamic, gas analysis and metabolic repercussions of high transient pressures of pneumoperitoneum for a short period of time to ensure greater security for introduction of the first trocar.

METHODS

sixty-seven patients undergoing laparoscopic procedures were studied and randomly distributed in P12 group: n=30 (intraperitoneal pressure [IPP] 12mmHg) and P20 group: n=37 (IPP of 20mmHg). Mean arterial pressure (MAP) was evaluated by catheterization of the radial artery; and through gas analysis, pH, partial pressure of oxygen (PaO2), partial pressure of CO2 (PaCO2), bicarbonate (HCO3) and alkalinity (BE) were evaluated. These parameters were measured in both groups at time zero before pneumoperitoneum (TP0); at time 1 (TP1) when IPP reaches 12mmHg in both groups; at time 2 (TP2) after five min with IPP=12mmHg in P12 and after 5min with IPP=20mmHg at P20; and at time 3 (TP3) after 10min with IPP=12mmHg in P12 and with return of IPP from 20 to 12mmHg, starting 10min after TP1 in P20. Different values from those considered normal for all parameters assessed, or the appearance of atypical organic phenomena, were considered as clinical changes.

RESULTS

there were statistically significant differences in P20 group in MAP, pH, HCO3 and BE, but within normal limits. No clinical and pathological changes were observed.

CONCLUSIONS

high and transient intra-abdominal pressure causes changes in MAP, pH, HCO3 and BE, but without any clinical impact on the patient.

Evaluation of Effects of Intraperitoneal CO2 Pressure in Laparoscopic Operations on Kidney, Pancreas, Liver and Spleen in Dogs

Background

During laparoscopy, insufflation of an inert gas in the peritoneal cavity creates a working space to facilitate surgery. The space should be large enough to facilitate surgery without increasing intra-abdominal pressure (IAP) over a threshold limit (usually 15 mm Hg).

Objectives

This experimental study was performed to evaluate the effects of increasing in intra-abdominal pressure on internal organs.

Materials and Methods

Twenty female mixed breed dogs (20 ± 3 kg, 18 ± 1.2 months) were selected. They were randomly divided to two groups (n = 10). The intra-abdominal pressure was maintained 12 mm Hg and 20 mm Hg during the operation in control group and in test group respectively.

Results

Histopathologic evaluations revealed more pathological changes at the kidney of all the dogs in test group in comparison to control group.

Conclusions

Our findings revealed that organs that their blood supplies are related to one single or two arteries and their blood drainage are related to one or two veins are more sensitive to increased intra-abdominal pressure.

A multidisciplinary evidence-based guideline for minimally invasive surgery.: Part 1: entry techniques and the pneumoperitoneum

The Dutch Society for Endoscopic Surgery together with the Dutch Society of Obstetrics and Gynecology initiated a multidisciplinary working group to develop a guideline on minimally invasive surgery to formulate multidisciplinary agreements for minimally invasive surgery aiming towards better patient care and safety. The guideline development group consisted of general surgeons, gynecologists, an anesthesiologist, and urologist authorized by their scientific professional association. Two advisors in evidence-based guideline development supported the group. The guideline was developed using the "Appraisal of Guidelines for Research and Evaluation" instrument. Clinically important aspects were identified and discussed. The best available evidence on these aspects was gathered by systematic review. Recommendations for clinical practice were formulated based on the evidence and a consensus of expert opinion. The guideline was externally reviewed by members of the participating scientific associations and their feedback was integrated. Identified important topics were: laparoscopic entry techniques, intra-abdominal pressure, trocar use, electrosurgical techniques, prevention of trocar site herniation, patient positioning, anesthesiology, perioperative care, patient information, multidisciplinary user consultation, and complication registration. The text of each topic contains an introduction with an explanation of the problem and a summary of the current literature. Each topic was discussed, considerations were evaluated and recommendations were formulated. The development of a guideline on a multidisciplinary level facilitated a broad and rich discussion, which resulted in a very complete and implementable guideline.

Risks associated with laparoscopic entry: guidelines for clinical practice from the French College of Gynaecologists and Obstetricians

The aim of these recommendations of the French National College of Gynaecologists and Obstetricians was to focus the surgeon's attention on those aspects which could allow him/her to prevent, or at least limit, the incidence of these serious complications, in the absence of a previous laparotomy or specific risk factors (obesity, gauntness, large pelvic mass or pregnancy), four widely evaluated techniques can be used in a first line approach (Grade B): blind trans-umbilical technique following creation of pneumoperitoneum with a needle, open laparoscopy (Hasson technique), left upper quadrant entry (pneumoperitoneum and insertion of the first trocar) and direct trans-umbilical trocar with no prior pneumoperitoneum. The currently existing trials do not allow one or another of these techniques to be preferred. Radially expanding insertion systems and optical trocars cannot be recommended as a first-line approach, as a consequence of their currently insufficient degree of evaluation (Grade C). Trans-umbilical (blind or open) laparoscopic entry in a slim woman must be associated with care, as a result of the proximity of the large vessels (Grade B). If a blind trans-umbilical insertion technique is decided upon, one option can be to insufflate into the left upper quadrant (professional consensus). In the case of a previous midline laparotomy, whatever the technique used, initial entry is recommended at a distance from the scars (Grade B). It is recommended to carry out micro-laparoscopy in the LUQ, because this is the most completely evaluated technique for this indication (Grade C). One option is to use open laparoscopy at a distance from the existing scars (professional consensus). During pregnancy, the insertion position of the first laparoscopic trocar will need to be adapted according to the volume of the uterus (Grade B). Starting from 14WG, trans-umbilical Veress needle insufflation is contraindicated (Grade C). Two trocar insertion techniques are thus recommended: open laparoscopy (using the trans-umbilical or supra-umbilical routes, depending on the volume of the uterus) or micro-laparoscopy via the left upper quadrant (Grade C). After the second quarter of pregnancy, with laparoscopy the patient will need to be placed on a table inclined towards her left side, in order to minimize compression of the inferior vena cava (Grade B). In the case of laparoscopy during pregnancy, the insufflation pressure must be maintained at a maximum of 12mmHg (Grade B). After 24WG, if laparoscopy is performed, it is recommended to apply open laparoscopy, above the level of the umbilicus (professional consensus). Patients must be informed of the risks inherent to the insertion of trocars during laparoscopy (vascular, bowel or bladder injury) (Grade B). The more benign the pathology requiring an operation, the more detailed the supplied information must be, including that concerning rare but serious complications (Grade B).

A new valve-less trocar for urologic laparoscopy: initial evaluation

INTRODUCTION

Laparoscopic trocars typically maintain pneumoperitoneum using trap door valves and silicone seals. However, valves and seals hinder passage of instruments, cause lens smudging, trap specimens and needles being removed from the abdominal cavity, and lose their seal with repeated instrument exchange.

AIM

The aim of the present study was to evaluate the feasibility of a newly designed valve-less trocar.

METHODS

The valve-less trocar system creates a curtain of forced gas to maintain pneumoperitoneum. A separate unit filters smoke and recirculates captured escaping gas. The valve-less trocar was trialed in consecutive laparoscopic renal procedures of a single surgeon. Perioperative parameters and outcomes were collected and analyzed. The system's safety, advantages, and disadvantages were evaluated. Insufflation gas usage, elimination, and absorption were also measured.

RESULTS

Twenty-five patients underwent laparoscopic renal procedures using the valve-less trocar system. The procedures included laparoscopic partial, radical, and donor nephrectomy. The mean patient age was 58.26 years. The mean operative time was 125 minutes and the mean drop in Hb for the cohort was 2.34 g/dL (range 0.4-5.4). Two patients developed subcutaneous emphysema and of the two patients, one developed clinically insignificant pneumomediastinum postoperatively. There were no postoperative complications. The surgeon noted that the use of a valve-less trocar decreased smudging of laparoscopes, expeditiously evacuated smoke during cauterization leading to improved visualization, maintained pneumoperitoneum even while suctioning, and resulted in easy extraction of specimens and needles. It was noted that insufflation gas consumption was low and CO(2) elimination was not impaired.

CONCLUSION

Use of a valve-less trocar is safe. Decreased laparoscope smudging may translate into decreased operative times and reduced gas consumption may equate to cost savings. Additionally, its use brings several advantages and convenience to the operating surgeon. However, the system should be compared with conventional trocars prospectively to demonstrate clinical and economic benefit.

Albumin infusion fails to restore circulatory function following paracentesis of tense ascites as assessed by beat-to-beat haemodynamic measurements

AIMS

To study whether circulatory changes during large volume paracentesis (LVP) in patients with liver cirrhosis and tense ascites as assessed by novel non-invasive haemodynamic measuring technology are reversed by subsequent albumin infusion.

MATERIALS AND METHODS

Eleven patients with portal hypertensive ascites secondary to liver cirrhosis of Child's class B or C were studied during LVP (10.7 +/- 4.4 l) and subsequent infusion of albumin. Digital arterial pulse waves were continuously measured by vascular unloading technique providing data for beat-to-beat values of systolic (P(s)), diastolic (P(d)) and mean arterial pressures (P(m)), respectively, as well as for heart rate (F(h)), stroke volume (V(s)), cardiac output (Q(co)) and peripheral resistance (R). Data extrapolated to the end of paracentesis, albumin infusion and follow-up phases were compared with the end of the equilibration phase.

RESULTS

At the end of paracentesis, P(s), P(m) and P(d) changed by -14 +/- 15% (p < 0.05), -16 +/- 11% (p < 0.01) and -17 +/- 11% (p < 0.001), respectively, whereas Q(co) and F(h) did not change substantially. There was a highly significant increase in V(s) by +21 +/- 25% (p < 0.01). The largest change was seen in R which significantly decreased by -29 +/- 24% (p < 0.01). This change was not reversed by infusion of albumin and persisted up to the end of follow-up.

CONCLUSION

The haemodynamic changes following LVP appear to be first and foremost controlled by changes in peripheral resistance with insufficient cardiac compensation. Further studies combining albumin with vasopressors for prevention of paracentesis-induced circulatory changes are needed.

Laparoscopic entry: a review of techniques, technologies, and complications

OBJECTIVE

To provide clinical direction, based on the best evidence available, on laparoscopic entry techniques and technologies and their associated complications.

OPTIONS

The laparoscopic entry techniques and technologies reviewed in formulating this guideline include the classic pneumoperitoneum (Veress/trocar), the open (Hasson), the direct trocar insertion, the use of disposable shielded trocars, radially expanding trocars, and visual entry systems.

OUTCOMES

Implementation of this guideline should optimize the decision-making process in choosing a particular technique to enter the abdomen during laparoscopy.

EVIDENCE

English-language articles from Medline, PubMed, and the Cochrane Database published before the end of September 2005 were searched, using the key words laparoscopic entry, laparoscopy access, pneumoperitoneum, Veress needle, open (Hasson), direct trocar, visual entry, shielded trocars, radially expanded trocars, and laparoscopic complications.

VALUES

The quality of evidence was rated using the criteria described in the Report of the Canadian Task Force on the Periodic Health Examination. RECOMMENDATIONS AND SUMMARY STATEMENT: 1. Left upper quadrant (LUQ, Palmer's) laparoscopic entry should be considered in patients with suspected or known periumbilical adhesions or history or presence of umbilical hernia, or after three failed insufflation attempts at the umbilicus. (II-2 A) Other sites of insertion, such as transuterine Veress CO(2) insufflation, may be considered if the umbilical and LUQ insertions have failed or have been considered and are not an option. (I-A) 2. The various Veress needle safety tests or checks provide very little useful information on the placement of the Veress needle. It is therefore not necessary to perform various safety checks on inserting the Veress needle; however, waggling of the Veress needle from side to side must be avoided, as this can enlarge a 1.6 mm puncture injury to an injury of up to 1 cm in viscera or blood vessels. (II-1 A) 3. The Veress intraperitoneal (VIP-pressure </= 10 mm Hg) is a reliable indicator of correct intraperitoneal placement of the Veress needle; therefore, it is appropriate to attach the CO(2) source to the Veress needle on entry. (II-1 A) 4. Elevation of the anterior abdominal wall at the time of Veress or primary trocar insertion is not routinely recommended, as it does not avoid visceral or vessel injury. (II-2 B) 5. The angle of the Veress needle insertion should vary according to the BMI of the patient, from 45 degrees in non-obese women to 90 degrees in obese women. (II-2 B) 6. The volume of CO(2) inserted with the Veress needle should depend on the intra-abdominal pressure. Adequate pneumoperitoneum should be determined by a pressure of 20 to 30 mm Hg and not by predetermined CO(2) volume. (II-1 A) 7. In the Veress needle method of entry, the abdominal pressure may be increased immediately prior to insertion of the first trocar. The high intraperitoneal (HIP-pressure) laparoscopic entry technique does not adversely affect cardiopulmonary function in healthy women. (II-1 A) 8. The open entry technique may be utilized as an alternative to the Veress needle technique, although the majority of gynaecologists prefer the Veress entry. There is no evidence that the open entry technique is superior to or inferior to the other entry techniques currently available. (II-2 C) 9. Direct insertion of the trocar without prior pneumoperitoneum may be considered as a safe alternative to Veress needle technique. (II-2) 10. Direct insertion of the trocar is associated with less insufflation-related complications such as gas embolism, and it is a faster technique than the Veress needle technique. (I) 11. Shielded trocars may be used in an effort to decrease entry injuries. There is no evidence that they result in fewer visceral and vascular injuries during laparoscopic access. (II-B) 12. Radially expanding trocars are not recommended as being superior to the traditional trocars. They do have blunt tips that may provide some protection from injuries, but the force required for entry is significantly greater than with disposable trocars. (I-A) 13. The visual entry cannula system may represent an advantage over traditional trocars, as it allows a clear optical entry, but this advantage has not been fully explored. The visual entry cannula trocars have the advantage of minimizing the size of the entry wound and reducing the force necessary for insertion. Visual entry trocars are non-superior to other trocars since they do not avoid visceral and vascular injury. (2 B).

Effect of body habitus and parity on insufflated CO2 volume at various intraabdominal pressures during laparoscopic access in women

STUDY OBJECTIVE

To determine height, weight, body mass index (BMI), parity, and age effect on the volume of CO2 pneumoperitoneum during laparoscopic access in women.

DESIGN

Prospective observational cohort study (Canadian Task Force classification II-1).

SETTING

University-affiliated teaching hospital.

PATIENTS

From January through June 2004, 100 healthy women underwent operative laparoscopic surgery consecutively by the senior author (GAV). Indications were: chronic pelvic pain (CPP, n = 66), pelvic mass (n = 7), CPP and pelvic mass (n = 4), infertility (n = 23). Median (range) height, weight, BMI, parity and age were 1.65 m (1.45-1.85 m), 70 kg (43-118 kg), 25.5 kg/m2 (17-39 kg/m2), 1.1 (0-5), and 34 years (19-58 years), respectively.

INTERVENTIONS

While in supine position, patients received general endotracheal anesthesia and muscle relaxants. Pneumoperitoneum was established by reusable Veres needle. The insufflated CO2 volume was serially recorded at intraperitoneal insufflation pressures (IPIPs) of 10, 15, 20, 25, and 30 mm Hg. The primary 10-mm trocar was introduced at IPIP of 30 mm Hg. Upon entering the peritoneal cavity, the abdominal contents were visualized with the laparoscope to ensure there was no injury, and the IPIP was immediately reduced back to the operating pressure of 15 mm Hg before switching the patient to the Trendelenburg position.

MEASUREMENTS AND MAIN RESULTS

The mean (SD) insufflated CO2 volumes at 10, 15, 20, 25, and 30 mm Hg were 1.7 (0.74) L, 3.1 (0.9) L, 3.96 (1.05) L, 4.42 (1.1) L and 4.72 (1.14) L, respectively. Using multivariate analysis, we demonstrated that at 20 to 30 mm Hg the insufflated CO2 volume correlated positively with the height, weight and BMI of women. Parity correlated positively at all pressures. There was no correlation with age at any pressure.

CONCLUSIONS

Higher CO2 volume is required to establish appropriate pneumoperitoneum in tall, overweight, and parous women at 20 to 30 mm Hg. Setting the IPIP at 20 to 30 mm Hg before primary trocar insertion eliminates the need to monitor CO2 insufflated volume regardless of women's age, parity, and body habitus.

The ABCs of a safer laparoscopic entry

It is well known that at least 50% of laparoscopic complications occur during the initial entry into the abdomen regardless of the method used. There is evidence that most gynecologists practice the "classic" or closed laparoscopic entry. There is no evidence that the closed entry is more or less dangerous than the other existing methods of entry. Entry-related complications have been minimized by the following three steps: low initial Veres intraperitoneal pressure indicating correct placement of the Veres needle; transient high-pressure pneumoperitoneum before primary trocar/cannula insertion; and visual entry with the Ternamian cannula. Following the above steps, no entry complications have been encountered by the author in more than 3000 consecutive laparoscopies.

Effect of body habitus and parity on the initial Veres intraperitoneal CO2 insufflation pressure during laparoscopic access in women

STUDY OBJECTIVES

Since most gynecologists use the Veres/trocar entry, and because the Veres intraperitoneal (VIP) pressure appears to be the most reliable indicator of correct Veres needle placement, the objective of this study was to determine the effect of height, weight, body mass index (BMI), parity, and age on the initial Veres intraperitoneal CO2 insufflation pressure during laparoscopic access in women.

DESIGN

Prospective observational cohort study (Canadian Task Force classification II-1).

SETTING

University affiliated teaching hospital.

PATIENTS

We prospectively collected data on 356 women undergoing laparoscopy for a variety of indications by the senior author (G.A.V.). The median and (range) for height, weight, BMI, parity, and age were 1.64 m (1.45-1.85 m), 65 kg (40-120 kg), 24.3 kg/m2 (16-47 kg/m2), 1 (0-5) and 34 years (18-87 yrs), respectively.

INTERVENTION

Under general endotracheal anesthesia including muscle relaxants and with the patient in appropriate stirrups in the horizontal position, a nondisposable Veres needle was inserted at the umbilicus or left upper quadrant (Palmer's point) with CO2 flowing at 1 L/min. The initial Veres intraperitoneal insufflation pressure was recorded once the Veres needle was believed to be in the peritoneal cavity.

MEASUREMENTS AND MAIN RESULTS

The mode and the median VIP pressure was 4 mm Hg with a range of 2 to 10 mm Hg. With multivariate analysis, the VIP pressure correlated positively with the weight (r = 0.518, p <.001) and BMI (r = 0.545, p <.001) and negatively with the parity (r = -0.179, p <.001) of women. The correlation of the VIP pressure with height and age was r = 0.029 (p = .591) and r = -0.044 (p = .411), respectively.

CONCLUSION

A VIP pressure < or =10 mm Hg indicates intraperitoneal placement of the Veres needle. The VIP pressure correlates positively with the weight and BMI and negatively with the parity of women. There is no correlation of the VIP pressure with women's height and age.