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

Comparison of the effect of general anesthesia and spinal anesthesia technique combined with general anesthesia on intraabdominal volume during gynecological laparoscopy

PURPOSE

We aimed to investigate the effect of spinal anesthesia which will be performed simultaneously with general anesthesia on the site of operation with the same pressure.

MATERIAL AND METHOD

This study was conducted as a randomized, prospective clinical study on 40 patients who were randomly divided into two groups. Twenty women underwent general anesthesia (Group GA) and 20 women underwent spinal anesthesia with general anesthesia (Group SGA). For all cases, preoperative height, weight, waist circumference, body mass index (kg/m² ), the distance between both spina iliaca anterior superior, the distance of the intersection of both ribs with an imaginary line drawn over the anterior axillary line, suprapubic bone-umbilical, umbilical-xiphoid, and suprapubic bone-xiphoid distance from the midline of the abdomen were measured. Moreover, while the patient was lying in the neutral position on the operating table, the height of the highest point of the abdomen to the operating table was also measured. These measurements were repeated at intra-abdominal pressure (IAP) 14 and 25 mmHg. The amount of intra-abdominal insufflated CO₂ was also recorded at IAP 14 and 25 mmHg.

RESULTS

When the intra-abdominal insufflation volumes of both groups were compared at 14 and 25 mmHg, respectively, there was no statistical difference (p: 0.54, p: 0.40). When 14 and 25 mmHg were compared in all cases, a statistically significant difference was observed in other measurements except in xiphoid-umbilical distance (p < 0.05).

CONCLUSION

We found that spinal anesthesia combined with GA had no effect on the abdominal volume and anthropometric measurements in laparoscopic procedures.

A novel method for monitoring abdominal compliance to optimize insufflation pressure during laparoscopy

BACKGROUND

Abdominal compliance describes the ease of expansion of the abdominal cavity. Several studies highlighted the importance of monitoring abdominal compliance (Cab) during the creation of laparoscopic workspace to individualize the insufflation pressure. The lack of validated clinical monitoring tools for abdominal compliance prevents accurate tailoring of insufflation pressure. Oscillometry, also known as the forced oscillation technique (FOT), is currently used to measure respiratory mechanics and has the potential to be adapted for monitoring abdominal compliance. This study aimed to define, develop and evaluate a novel approach which can monitor abdominal compliance during laparoscopy using endoscopic oscillometry.

MATERIALS AND METHODS

Endoscopic oscillometry was evaluated in a porcine model for laparoscopy. A custom-built insufflator was developed for applying an oscillatory pressure signal superimposed onto a mean intra-abdominal pressure. This insufflator was used to measure the abdominal compliance at insufflation pressures ranging from 5 to 20 hPa (3.75 to 15 mmHg). The measurements were compared to the static abdominal compliance, which was measured simultaneously with computed tomography imaging.

RESULTS

Endoscopic oscillometry recordings and CT images were obtained in 10 subjects, resulting in 76 measurement pairs for analysis. The measured dynamic Cab ranged between 0.0216 and 0.261 L/hPa while the static Cab based on the CT imaging ranged between 0.0318 and 0.364 L/hPa. The correlation showed a polynomial relation and the adjusted R-squared was 97.1%.

CONCLUSIONS

Endoscopic oscillometry can be used to monitor changes in abdominal compliance during laparoscopic surgery, which was demonstrated in this study with a comparison with CT imaging in a porcine laparoscopy model. Use of this technology to personalize the insufflation pressure could reduce the risk of applying excessive pressure and limit the drawbacks of insufflation.

Development and evaluation of a numerical spine model comprising intra-abdominal pressure for use in assessing physiological changes on abdominal compliance and spinal stability

BACKGROUND

Abdominal compliance is the "measure of ease of abdominal expansion" and determines whether a patient can withstand high intra-abdominal pressures. Thus, high compliance indicates that the abdomen can expand relatively freely, while low compliance restricts abdominal expansion. The global objective of the present work is to evaluate the effect of physiological changes on abdominal compliance using a comprehensive spine finite element model inclusive of intra-abdominal pressure.

METHODS

The effect of changing Young's modulus, abdominal wall thickness, and abdominal radii on abdominal compliance were evaluated. Intra-abdominal pressure and thoracolumbar fascia forces were also evaluated to assess abdominal physiological changes effects on overall static spinal stability.

FINDINGS

Results showed that as wall thickness increased, compliance decreased. Similar findings were made with an increase in abdominal radius and Young's modulus. Furthermore, the active reduction in compliance, caused by increased elasticity and abdominal radius, resulted in an increase in spinal supportive forces originating from the thoracolumbar fascia and intra-abdominal pressurization, along with an increase in spine displacement from its original stable position. There was no clear stability trend for the case of changing abdominal wall thickness as fluctuations were present.

INTERPRETATION

Investigated mechanics and data trends suggested that dangerously low compliance levels might result from poor abdominal elasticity and thickening fat layers. This led to a direct discussion and recommendations for obesity conditions and laparoscopy applications. Lastly, static spinal stability showed to improve through increasing active abdominal compliance by means of actively engaging abdominal pressure, hence augmenting abdominal active elasticity.

Proposal of a Novel Index of Abdominal Compliance and the Association With Postoperative Pain After Laparoscopic Inguinal Hernia Repair

BACKGROUND

In laparoscopic surgery, low pneumoperitoneum pressure is reported to reduce pain, which suggests that easing abdominal expansion is crucial for less postoperative pain. However, although abdominal compliance (AC) is associated with the degree of abdominal expansion, the role of AC in pain by pneumoperitoneum is unknown. In this study, we devised a novel index as a surrogate of AC to evaluate the association between AC and postoperative pain in laparoscopic inguinal hernia repair.

MATERIALS AND METHODS

We reviewed 83 patients who underwent elective transabdominal preperitoneal repair from 2019 to 2021 at Heisei Memorial Hospital. Insufflation pressure was set to low pressure (8 mm Hg). The abdominal compliance index [ACI; insufflated intra-abdominal volume (L)/body surface area (m2)] was utilized to evaluate the association between AC and postoperative pain.

RESULTS

ACI was evaluated in 30 patients. Median ACI was 1.53 (1.00 to 2.48) L/m2. Although there was no difference in the average body constitution, the high ACI group (n=15) had significantly higher intra-abdominal volume at 8 mm Hg pressure, compared with the low ACI group (n=15) (3.1 vs. 2.1 L, P<0.0001). The high ACI group had significantly higher pain than the low ACI group on the day of surgery (2.0 vs. 1.0, P=0.006) and the day after (0.8 vs. 0.3, P=0.007). In addition, 46.7% of the patients in the high ACI group experienced pneumoperitoneum-associated pain, whereas patients in the low ACI group experienced incision pain only. Additional analgesics were administered in 53.3% of the high ACI group, compared with 33.3% in the low ACI group.

CONCLUSIONS

AC was suggested to be a vital factor of postoperative pain after laparoscopic inguinal hernia repair. Patients with high AC may be susceptible to higher pain by pneumoperitoneum, even in low-pressure settings.

To drain or not to drain: the association between residual intraperitoneal gas and post-laparoscopic shoulder pain for laparoscopic cholecystectomy

Residual intra-peritoneal gas may be associated with post-laparoscopic shoulder pain (PLSP), which is a frequently and disturbance compliant after surgery. Herein, we aimed to examine whether expiring residual gas via a surgical drain reduces the frequency and intensity of PLSP in the first day after laparoscopic cholecystectomy. 448 participants were enrolled in this prospective cohort study. The incidence and severity of PLSP after surgery were recorded. Of these, the cumulative incidence of PLSP in the drain group was lower particularly at the 12th postoperative hour (18.3% vs. 27.6%; P = 0.022), 24th postoperative hour (28.8% vs. 38.1%; P = 0.039), and throughout the first postoperative day (P = 0.035). The drain group had less severe PLSP (crude Odds ratio, 0.66; P = .036). After adjustment using inverse probability of treatment weighting, the drain group also had a significant lower PLSP incidence (adjusted hazard ratio = 0.61, P < 0.001), and less severe PLSP (adjusted odds ratio = 0.56, P < 0.001). In conclusion, the maneuver about passive force to expel residual gas, surgical drain use, contributes to reduce the incidence and severity of PLSP, suggesting that to minimize residual gas at the end of surgery is useful to attenuate PLSP.

Laparoscopic Entry Technique Using a Veress Needle Insertion with and without Concomitant CO2 Insufflation: A Randomized Controlled Trial

STUDY OBJECTIVE

To compare the time and number of attempts needed for successful Veress needle entry during laparoscopic surgery using concomitant versus subsequent CO₂ insufflation approaches.

DESIGN

Randomized controlled trial.

SETTING

University teaching hospital.

PATIENTS

One hundred consecutive patients scheduled for laparoscopic surgery by 2 high-volume laparoscopic surgeons were screened and randomized, and 95 of these were included in the final analysis. Ninety (45 in each group) was the precalculated priori number of patients needed to detect a 50% difference in the time (seconds) to obtain adequate insufflation with 90% power and alpha of 5%.

INTERVENTIONS

Patients were randomized to either Veress needle entry with concomitant (Con) or subsequent (Sub) CO₂ insufflation.

MEASUREMENTS AND MAIN RESULTS

Forty-six patients were randomized to the Con group and 49 to the Sub group. Patient age, body mass index, prior surgical history, presence of adhesions, and type of procedure performed were similar between both groups. The median time required for adequate insufflation in the Con group was 103.5 seconds (Q1-Q3, 80.0-130.0) compared with 113.0 seconds (Q1-Q3, 102.0-144.0) in Sub group (p = .16). Approximately 89% (95% confidence interval, 80.1%-98.1%) of patients in Con group achieved successful entry in the first attempt compared with only 67% (95% confidence interval, 54.2%-80.0%) in Sub group (p = .01). The incidence of preperitoneal insufflation and failed entry was comparable between the 2 groups. No patient developed solid organ, visceral, or vascular injuries; gas embolism; or case conversion to laparotomy in relation to the Veress needle entry technique.

CONCLUSION

Veress needle entry with concomitant CO₂ insufflation was associated with a higher rate of successful entry during the first attempt of Veress needle insertion. The total time required for insufflation and rates of complications between the 2 techniques were similar.

More Reasonable Animal Model for Study the Effect of Pneumoperitoneum on Abdominal Tumor Cells

Background:

Many animal experimental studies showed that abdominal tumor cells will be widely spread during laparoscopic treatment and grow into metastases. These results are different from clinical observations. There is a hypothesis that too much tumor cells was injected in the animals lead to the results of theses bias. We aim to learn the difference of abdominal cavity volume between human body and the nude mice and to determine reasonable amount of tumor cells in the animal experiments.

Methods:

The insufflated CO₂ volume which represents the capacity of the abdominal cavity was recorded during laparoscopic process in 212 patients and 20 nude mice respectively, the relative volume of nude mice and human body was calculated. Based on data from the literature and this study , the amount of tumor cells in the animal experiments was determined. According to these data, we set up a new animal model and a traditional one respectively, and compared the rate of successful modeling and tumor formation between two animal models.

Results:

The intraperitoneal volumes of humans and nude mice were 3.01±0.36 L and 0.011±0.001 L respectively.The number of tumor cells that be uesd in animal should be approximately 0.26×10⁵ in terms of known data in human beings. Compared with the traditional animal model which formed a large number of intraperitoneal tumor metastasis, the new animal model was shows more moderately, and the rate of successful modeling was similar.

Conclusion:

In animal experiments, to simulate the clinical situation, about 0.26×10⁵ tumor cells should be inject in peritoneal cavity of the nude mice.

Abdominal intra-compartment syndrome - a non-hydraulic model of abdominal compartment syndrome due to post-hepatectomy hemorrhage in a man with a localized frozen abdomen due to extensive adhesions: a case report

BACKGROUND

Postoperative hemorrhage is a significant cause of morbidity and mortality following liver resection. It typically presents early within the postoperative period, and conservative management is possible in the majority of cases. We present a case of late post-hepatectomy hemorrhage associated with overt abdominal compartment syndrome resulting from a localized functional compartment within the abdomen.

CASE PRESENTATION

A 68-year-old white man was readmitted with sudden onset of upper abdominal pain, vomiting, and hemodynamic instability 8 days after an uneventful hepatic resection for metachronous colon cancer metastasis. A frozen abdomen with adhesions due to complicated previous abdominal surgeries was encountered at the first intervention, but the surgery itself and initial recovery were otherwise unremarkable. Prompt response to fluid resuscitation at admission was followed by a computed tomography of his abdomen that revealed active arterial hemorrhage in the liver resection site and hemoperitoneum (estimated volume <2 L). Selective arteriography successfully identified and embolized a small bleeding branch of his right hepatic artery. He remained hemodynamically stable, but eventually developed overt abdominal compartment syndrome. Surgical exploration confirmed a small volume of ascites and blood clots (1.2 L) under significant pressure in his supramesocolic region, restricted by his frozen lower abdomen, which we evacuated. Dramatic improvement in his ventilatory pressure was immediate. His abdomen was left open and a negative pressure device was placed for temporary abdominal closure. The fascia was formally closed after 48 hours. He was discharged home at postoperative day 6.

CONCLUSIONS

Intra-abdominal pressure and radiologic findings of intra-abdominal hemorrhage should be carefully interpreted in patients with extensive intra-abdominal adhesions. A high index of suspicion and detailed understanding of abdominal compartment mechanics are paramount for the timely diagnosis of abdominal compartment syndrome in these patients. Clinicians should be aware that abnormal anatomy (such as adhesions) coupled with localized pathophysiology (such as hemorrhage) can create a so-named abdominal intra-compartment syndrome requiring extra vigilance to diagnose.

The neglected role of abdominal compliance in organ-organ interactions

This article is one of ten reviews selected from the Annual Update in Intensive Care and Emergency medicine 2016. Other selected articles can be found online at http://www.biomedcentral.com/collections/annualupdate2016. Further information about the Annual Update in Intensive Care and Emergency Medicine is available from http://www.springer.com/series/8901.

Magnetic Surgical Instruments for Robotic Abdominal Surgery

This review looks at the implementation of magnetic-based approaches in surgical instruments for abdominal surgeries. As abdominal surgical techniques advance toward minimizing surgical trauma, surgical instruments are enhanced to support such an objective through the exploration of magnetic-based systems. With this design approach, surgical devices are given the capabilities to be fully inserted intraabdominally to achieve access to all abdominal quadrants, without the conventional rigid link connection with the external unit. The variety of intraabdominal surgical devices are anchored, guided, and actuated by external units, with power and torque transmitted across the abdominal wall through magnetic linkage. This addresses many constraints encountered by conventional laparoscopic tools, such as loss of triangulation, fulcrum effect, and loss/lack of dexterity for surgical tasks. Design requirements of clinical considerations to aid the successful development of magnetic surgical instruments, are also discussed.

Abdominal compliance: A bench-to-bedside review

Abdominal compliance (AC) is an important determinant and predictor of available workspace during laparoscopic surgery. Furthermore, critically ill patients with a reduced AC are at an increased risk of developing intra-abdominal hypertension and abdominal compartment syndrome, both of which are associated with high morbidity and mortality. Despite this, AC is a concept that has been neglected in the past.AC is defined as a measure of the ease of abdominal expansion, expressed as a change in intra-abdominal volume (IAV) per change in intra-abdominal pressure (IAP):AC = ΔIAV / ΔIAPAC is a dynamic variable dependent on baseline IAV and IAP as well as abdominal reshaping and stretching capacity. Whereas AC itself can only rarely be measured, it always needs to be considered an important component of IAP. Patients with decreased AC are prone to fulminant development of abdominal compartment syndrome when concomitant risk factors for intra-abdominal hypertension are present.This review aims to clarify the pressure-volume relationship within the abdominal cavity. It highlights how different conditions and pathologies can affect AC and which management strategies could be applied to avoid serious consequences of decreased AC.We have pooled all available human data to calculate AC values in patients acutely and chronically exposed to intra-abdominal hypertension and demonstrated an exponential abdominal pressure-volume relationship. Most importantly, patients with high level of IAP have a reduced AC. In these patients, only small reduction in IAV can significantly increase AC and reduce IAPs.A greater knowledge on AC may help in selecting a better surgical approach and in reducing complications related to intra-abdominal hypertension.

Deep neuromuscular block reduces intra-abdominal pressure requirements during laparoscopic cholecystectomy: a prospective observational study

BACKGROUND

Laparoscopic surgery causes specific post-operative discomfort and intraoperative cardiovascular, pulmonary, and splanchnic changes. The CO2 pneumoperitoneum-related intra-abdominal pressure (IAP) remains one of the main drivers of these changes. We investigated the influence of deep neuromuscular blockade (NMB) on IAP and surgical conditions.

METHODS

This is an open prospective single-subject design study in 20 patients (14 female/6 male) undergoing laparoscopic cholecystectomy. Inclusion criteria were 18 years or older, and American Society of Anesthesiologists classification 1 to 3. Under a standardised anaesthesia, lowest IAP providing adequate surgical conditions was assessed without NMB and with deep NMB [post-tetanic count (PTC)<2] with rocuronium. The differences between IAP allowing for an adequate surgical field before and after administration of rocuronium were determined, as were effects of patient gender, age, and body mass index.

RESULTS

Mean IAP without NMB was 12.75 (standard deviation 4.49) mmHg. Immediately after achieving a deep NMB, this was 7.20 (2.51). This pressure difference of 5.55 mmHg (5.08, P<0.001) dropped to 3.00 mmHg (4.30, P<0.01) after 15 min. Higher IAP differences were found in women compared with men. A modest inverse relationship was found between pressure difference and age.

CONCLUSIONS

We found an almost 25% lower IAP after a deep NMB compared with no block in laparoscopic cholecystectomy. Younger and female patients appear to benefit more from deep neuromuscular blockade to reduce IAP.

The interpretation of intra-abdominal pressures from animal models: the rabbit to human example

INTRODUCTION

The importance of the abdominal wall characteristics in intraabdominal pressure (IAP), intraabdominal hypertension (IAH) and abdominal compartment syndrome (ACS) are poorly understood. The applicability of laboratory research findings to human scenarios is unknown due to the potential differences in abdominal wall elastance (AWE) amongst species. The aims of the study are to describe the AWE curve in rabbits and to compare it to the available human data.

MATERIALS AND METHODS

Prospective experimental animal study in the setting of research laboratory. Male New Zealand White rabbits weighting 2.7 kg ± 0.1 kg, were anesthetized and the AWE was determined by infusion of lactated Ringer's solution into the peritoneal cavity whilst the IAP was measured. A meta-analysis of peer-reviewed studies was conducted to define human AWE.

RESULTS

The described AWE was lower in the rabbit than in humans. The function comparing human and rabbit was: log(e) human IAP = (0.58 log(e) rabbit IAP+1.6).

CONCLUSIONS

The AWE can vary amongst species. This study determined the relationship to allow the comparison of rabbit and human IAP. The proposed mathematical function is important for the advancement of interpretation and understanding of animal research into IAH and ACS. We recommend developing model-specific functions comparing individual animal models' IAP and that of humans.

Clinical review: Intra-abdominal hypertension: does it influence the physiology of prone ventilation?

Prone ventilation (PV) is a ventilatory strategy that frequently improves oxygenation and lung mechanics in critical illness, yet does not consistently improve survival. While the exact physiologic mechanisms related to these benefits remain unproven, one major theoretical mechanism relates to reducing the abdominal encroachment upon the lungs. Concurrent to this experience is increasing recognition of the ubiquitous role of intra-abdominal hypertension (IAH) in critical illness, of the relationship between IAH and intra-abdominal volume or thus the compliance of the abdominal wall, and of the potential difference in the abdominal influences between the extrapulmonary and pulmonary forms of acute respiratory distress syndrome. The present paper reviews reported data concerning intra-abdominal pressure (IAP) in association with the use of PV to explore the potential influence of IAH. While early authors stressed the importance of gravitationally unloading the abdominal cavity to unencumber the lung bases, this admonition has not been consistently acknowledged when PV has been utilized. Basic data required to understand the role of IAP/IAH in the physiology of PV have generally not been collected and/or reported. No randomized controlled trials or meta-analyses considered IAH in design or outcome. While the act of proning itself has a variable reported effect on IAP, abundant clinical and laboratory data confirm that the thoracoabdominal cavities are intimately linked and that IAH is consistently transmitted across the diaphragm--although the transmission ratio is variable and is possibly related to the compliance of the abdominal wall. Any proning-related intervention that secondarily influences IAP/IAH is likely to greatly influence respiratory mechanics and outcomes. Further study of the role of IAP/IAH in the physiology and outcomes of PV in hypoxemic respiratory failure is thus required. Theories relating inter-relations between prone positioning and the abdominal condition are presented to aid in designing these studies.

[Influence of volume increase on intra-abdominal pressure]

The aim of this review is to summarize the physiological and pathological aspects of the relationship between volume and intra-abdominal pressure (IAP). A capillary leak following trauma or inflammation can induce a volume shift into the abdomen. An increase of the IAP depends on the abdominal compliance, which is reduced by increases in intra-abdominal volume and pressure as well as by an upright body position and obesity. A pathological increase of IAP (>12 mmHg) depends on the amount and type of resuscitation volume and is known to cause increased morbidity und mortality. Colloids or hypertensive solutions can reduce IAP however, current data are still insufficient. Therapeutic options are IAP monitoring and decompression.