Intestinal histopathological changes in a porcine model of pneumoperitoneum-induced intra-abdominal hypertension.

BACKGROUND: Low splanchnic perfusion is an immediate effect of pneumoperitoneum-induced intra-abdominal hypertension (IAH). Anatomical structure results in the intestinal mucosa being the area most sensitive to hypoperfusion. The relationship between intestinal injury and clinical parameters of tissue perfusion [abdominal perfusion pressure (APP), gastric intramucosal pH (pHi) and lactic acid (Lc)] has not been previously studied. This study aimed to monitorize intestinal pathogenesis through sequential ileal biopsies and to measure APP, pHi, and Lc levels at different pneumoperitoneum-induced intra-abdominal pressures (20, 30, and 40 mmHg) to evaluate the potential relationships between them. MATERIALS AND METHODS: Fifty pigs were divided into four groups; a control group (C) and three experimental groups with different pneumoperitoneum-induced levels [20 mmHg (G20), 30 mmHg (G30), and 40 mmHg (G40)], that were maintained for 3 and 5 h. APP, pHi, and Lc were measured and ileal biopsies taken laparoscopically every 30 min. The mucosal damage was graded using the standardized Park's Score and animals were classified as injured (I+) or uninjured (I-). RESULTS: Different histopathological lesions were observed in groups G20, G30, and G40 but no damage observed in group C. A 33.3% of animals in G20 and G30 were I+ after 3 h, while 93.3% were injured in G40. After 5 h, histopathological lesions were no longer seen in some animals in G20 and only 10% were I+. Conversely, in G30 I+ pigs increased to 80% while those in G40 remained at 93.3% I+. The I+ animals had significantly lower APP and pHi than those I-. Lc was the clinical parameter that showed the earliest differences, with significantly higher figures in I+ animals. CONCLUSIONS: The evolution of intestinal injuries from pneumoperitoneum-induced IAH depends on the degree of IAP. These damages may be associated with decreases in APP and pHi, and increases in Lc.

Is intra-bladder pressure measurement a reliable indicator for raised intra-abdominal pressure? A prospective comparative study.

BACKGROUND: Intra-abdominal pressure (IAP) can be measured by several indirect methods; however, the urinary bladder is largely preferred. The aim of this study was to compare intra-bladder pressure (IBP) at different levels of IAPs and assess its reliability as an indirect method for IAP measurement. METHODS: We compared IBP with IAP in twenty-one patients undergoing laparoscopic cholecystectomy under general anesthesia. Measurements were recorded at increasing levels of insufflation pressures to approximately 22 mmHg. Pearson's correlation coefficient was calculated to establish the relationship between the two pressure measurements and Bland-Altman analysis was used to assess the limits of agreement between the two methods of measurements. RESULTS: The urinary bladder pressures reflected well the pressures in the abdominal cavity. Pearson correlation coefficient showed a good correlation between the two measurement techniques (r = 0.966, p < 0.0001) and Bland-Altman analysis indicated that the 95% limits of agreement between the two methods ranged from - 2.83 to 2.64. This range is accepted both clinically and according to the recommendations of the World Society of Abdominal Compartment Syndrome (WSACS). CONCLUSION: Our study showed that IBP measurement is a simple, minimally invasive method that may reliably estimates IAP in patients placed in supine position. Measurements for pressures higher than 12 mmHg may be less reliable. When applied clinically, this should alert the clinician to take safety measures to avoid abdominal compartment syndrome (ACS).

Biomechanical abdominal wall model applied to hernia repair.

BACKGROUND: Most surgical innovations require extensive preclinical testing before employment in the operative environment. There is currently no way to develop and test innovations for abdominal wall surgery that is cheap, repeatable and easy to use. In hernia repair, the required mesh overlap relative to defect size is not established. The aims of this study were to develop a biomechanical model of the abdominal wall based on in vivo pressure measurements, and to apply this to study mesh overlap in hernia repair. METHODS: An observational study of intra-abdominal pressure (IAP) levels throughout abdominal surgery was conducted to identify the peak perioperative IAP in vivo. This was then applied in the development of a surrogate abdominal wall model. An in vitro study of mesh overlap for various defect sizes was then conducted using this clinically relevant surrogate abdomen model. RESULTS: The mean peak perioperative IAP recorded in the clinical study was 1740 Pa, and occurred during awakening from anaesthesia. This was reproduced in the surrogate abdomen model, which was also able to replicate incisional hernia formation. Using this model, the mesh overlap necessary to prevent hernia formation up to 20 kPa was found, independent of anatomical variations, to be 2 × (defect diameter) + 25 mm. CONCLUSION: This study demonstrated that a surgically relevant surrogate abdominal wall model is a useful translational tool in the study of hernia repair. Surgical relevance This study examined the mesh overlap requirements for hernia repair, evaluated in a biomechanical model of the abdomen. Currently, mesh size is selected based on empirical evidence and may underpredict the requirement for large meshes. The study proposes a relationship between the defect size and mesh size to select the appropriate mesh size. Following further trials and investigations, this could be used in clinical practice to reduce the incidence of hernia recurrence.

Effects of walking speeds and carrying techniques on intra-abdominal pressure in women.

INTRODUCTION AND HYPOTHESIS: Walking speed and carrying technique affect intra-abdominal pressure (IAP) in women. In this study, we tested the feasibility of monitoring IAP outside the laboratory environment and compared IAP while study participants were (1) carrying 13.6 kg (similar to a 3-month old in car seat) in six different ways while walking 100 m; and (2) while walking 400 m at self-selected slow, normal, and fast paces. METHODS: Forty-six healthy women between 19 and 54 years completed the walking and lifting activities; the order for each was randomized. IAP was monitored with an intravaginal pressure transducer that wirelessly transmitted pressure data to a portable base station. We analyzed maximal peak IAP and area under the curve (AUC) IAP. RESULTS: Monitoring IAP outside of the laboratory was feasible. Mean maximal IAP during walking increased as pace increased: 42.5 [standard deviation (SD) 10.2], 50.5 (10.9), and 62.0 (12.1) cmH2O for slow, medium, and fast speeds, respectively: p < 0.0001 by mixed-model analysis of variance (ANOVA). The corresponding AUC of IAP for walking decreased as pace increased. The awkward carry, side carry, and front carry activities each resulted in higher mean maximal IAP [65.8 (10.6), 67.7 (12.8), and 77.3 (13.1) cmH2O, respectively] than the carry-in-backpack activity [55.5 (11.4) cmH2O; p < 0.0001]. CONCLUSION: Subtle variations in walking speed or method of carrying a toddler-size load can produce significant changes in IAP. Whether these changes increase the risk of pelvic floor disorders is not yet clear. However, these data suggest that further inquiry into optimal methods and appliances to assist women in carrying may create a lower IAP profile.

Subperitoneal extension of disease processes between the chest, abdomen, and the pelvis.

The subserous space is a large, anatomically continuous potential space that interconnects the chest, abdomen, and pelvis. The subserous space is formed from areolar and adipose tissue, and contains branches of the vascular, lymphatic, and nervous systems. As such, it provides one large continuous space in which many disease processes can spread between the chest, abdomen, and the pelvis.

[Immunological features of children with primary peritonitis].

An immunological research of the patients and control group with primary peritonitis was made. The main indices of immune response were in the range of age rates. However, the immune signs of foci of chronic inflammation were revealed in patients after operation. The consequences of disease (an abdominal cavity effusion) were eliminated during surgical interventions, but not the cause of the inflammation. Children with the primary peritonitis should be examined for detection of infection foci.

Validation of continuous intraabdominal pressure measurement: feasibility and accuracy assessment using a capsular device in in-vivo studies.

BACKGROUND: Monitoring Intraabdominal Pressure (IAP) is essential in critical care, as elevated IAP can lead to severe complications, including Abdominal Compartment Syndrome (ACS). Advances in technology, such as digital capsules, have opened new avenues for measuring IAP non-invasively. This study assesses the feasibility and effectiveness of using a capsular device for IAP measurement in an animal model. METHOD: In our controlled experiment, we anesthetized pigs and simulated elevated IAP conditions by infusing CO2 into the peritoneal cavity. We compared IAP measurements obtained from three different methods: an intravesical catheter (IAPivp), a capsular device (IAPdot), and a direct peritoneal catheter (IAPdir). The data from these methods were analyzed to evaluate agreement and accuracy. RESULTS: The capsular sensor (IAPdot) provided continuous and accurate detection of IAP over 144 h, with a total of 53,065,487 measurement triplets recorded. The correlation coefficient (R²) between IAPdot and IAPdir was excellent at 0.9241, demonstrating high agreement. Similarly, IAPivp and IAPdir showed strong correlation with an R² of 0.9168. CONCLUSION: The use of capsular sensors for continuous and accurate assessment of IAP marks a significant advancement in the field of critical care monitoring. The high correlation between measurements from different locations and methods underscores the potential of capsular devices to transform clinical practices by providing reliable, non-invasive IAP monitoring.

Optimizing working space in porcine laparoscopy: CT measurement of the effects of intra-abdominal pressure.

BACKGROUND: Several factors may affect volume and dimensions of the working space in laparoscopic surgery. The precise impact of these factors has not been well studied. In a porcine model, we used computed tomographic (CT) scanning for measuring working space volume and distances. In a first series of experiments, we studied the relationship between intra-abdominal pressure (IAP) and working space. METHODS: Eleven 20 kg pigs were studied under standardized anesthesia and volume-controlled ventilation. Cardiorespiratory parameters were monitored continuously, and blood gas samples were taken at different IAP levels. Respiratory rate was increased when ETCO2 exceeded 7 kPa. Breath-hold CT scans were made at IAP levels of 0, 5, 10, and 15 mmHg. Insufflator volumes were compared to CT-measured volumes. Maximum dimensions of pneumoperitoneum were measured on reconstructed CT images. RESULTS: Respiratory rate had to be increased in three animals. Mild hypercapnia and acidosis occurred at 15 mmHg IAP. Peak inspiratory pressure rose significantly at 10 and 15 mmHg. CT-measured volume increased relatively by 93 % from 5 to 10 mmHg IAP and by 19 % from 10 to 15 mmHg IAP. Comparing CT volumes to insufflator volumes gave a bias of 76 mL. The limits of agreement were -0.31 to +0.47, a range of 790 mL. The internal anteroposterior diameter increased by 18 % by increasing IAP from 5 to 10 mmHg and by 5 % by increasing IAP from 10 to 15 mmHg. At 15 mmHg, the total relative increase of the pubis-diaphragm distance was only 6 %. Abdominal width did not increase. CONCLUSIONS: CT allows for precise calculation of the actual CO2 pneumoperitoneum volume, whereas the volume of CO2 released by the insufflator does not. Increasing IAP up to 10 mmHg achieved most gain in volume and in internal anteroposterior diameter. At an IAP of 10 mmHg, higher peak inspiratory pressure was significantly elevated.

Activity restrictions after gynecologic surgery: is there evidence?

Many surgeons recommend rest and restricting activities to their patients after surgery. The aim of this review is to summarize the literature regarding types of activities gynecologic surgeons restrict and intra-abdominal pressure during specific activities and to provide an overview of negative effects of sedentary behavior (rest). We searched PubMed and Scopus for years 1970 until present and excluded studies that described recovery of activities of daily living after surgery as well as those that assessed intra-abdominal pressure for other reasons such as abdominal compartment syndrome and hypertension. For our review of intra-abdominal pressure, we excluded studies that did not include a generally healthy population, or did not report maximal intra-abdominal pressures. We identified no randomized trial or prospective cohort study that studied the association between postoperative activity and surgical success after pelvic floor repair. The ranges of intra-abdominal pressures during specific activities are large and such pressures during activities commonly restricted and not restricted after surgery overlap considerably. There is little concordance in mean peak intra-abdominal pressures across studies. Intra-abdominal pressure depends on many factors, but not least the manner in which it is measured and reported. Given trends towards shorter hospital stays and off work intervals, which both predispose women to higher levels of physical activity, we urge research efforts towards understanding the role of physical activity on recurrence of pelvic organ prolapse and urinary incontinence after surgery.

More complicated than it looks: the vagaries of calculating intra-abdominal pressure.

Activities thought to induce high intra-abdominal pressure (IAP), such as lifting weights, are restricted in women with pelvic floor disorders. Standardized procedures to assess IAP during activity are lacking and typically only focus on maximal IAP variably defined. Our intent in this methods article is to establish the best strategies for calculating maximal IAP and to add area under the curve and first moment of the area as potentially useful measures in understanding biologic effects of IAP. Thirteen women completed a range of activities while wearing an intravaginal pressure transducer. We first analyzed various strategies heuristically using data from 3 women. The measure that seemed to best represent maximal IAP was an average of the 3, 5, or 10 highest values, depending on activity, determined using a top-down approach, with peaks at least 1 second apart using algorithms written for Matlab computer software, we then compared this strategy with others commonly reported in the literature quantitatively using data from 10 additional volunteers. Maximal IAP calculated using the top-down approach differed for some, but not all, activities compared with the single highest peak or to averaging all peaks. We also calculated area under the curve, which allows for a time component, and first moment of the area, which maintains the time component while weighing pressure amplitude. We validated methods of assessing IAP using computer-generated sine waves. We offer standardized methods for assessing maximal area under the curve and first moment of the area for IAP to improve future reporting and application of this clinically relevant measure in exercise science.

Clinical evaluation of a wireless intra-vaginal pressure transducer.

OBJECTIVE: To describe the development, feasibility and validity of a wireless intra-vaginal pressure transducer (IVT) which can be used to measure intra-abdominal pressure in real-world settings. STUDY DESIGN: A feasibility study was conducted in sixteen physically active women to determine retention and comfort of various IVT prototype designs during activity. A criterion validity study was conducted among women undergoing urodynamic testing to determine the accuracy of the IVT prototypes when compared to accepted clinical standards. RESULTS: A final prototype wireless IVT was developed after four design revisions of the second generation model. The feasibility study found that women reported the final prototype comfortable to wear and easily retained during physical activity. Intra-abdominal pressure measurements from the final prototype IVT compared favorably to standard urodynamic transducers, thus confirming evidence of its utility. CONCLUSION: We have successfully advanced the design of a wireless, intra-vaginal pressure transducer which provides accurate measures of intra-abdominal pressure. The final wireless IVT is better tolerated by patients and overcomes limitations of traditional urodynamic testing while laying the foundations for intra-abdominal pressure monitoring outside of the clinic environment.

Answering the burning question of how transient receptor potential vanilloid-1 channel antagonists cause unwanted hyperthermia.

The treatment of chronic pain with new therapies that lack the side effects of existing analgesics is one of medicine's great unmet needs. Toward this goal, antagonists of the transient receptor potential vanilloid-1 (TRPV1) channel have shown some promise. However, the development of these compounds has been hindered by an unpleasant on-target hyperthermic side effect. With compelling evidence, the accompanying critical review by Romanovsky et al. (p. 228) regarding TRPV1 takes a position on the sites of action of TRPV1 agonists and antagonists on the thermoregulatory system that controls this side effect. From this comes insight on potential ways to overcome the unwanted hyperthermic action of TRPV1 antagonists.

System development for unrestrictive view and 4D shape acquisition in abdominal cavity operation using virtual space.

Laparoscopic surgery has been used for various areas of abdominal cavity. However, the laparoscope has limitation of its field of view and mobility. Our aim is to develop a new video camera system that acquires multiple viewpoints in the abdominal cavity. We designed a camera array that consisted of eight small camera modules. The camera array can change its shape so that it can be inserted into the abdominal cavity through trocar. Surgeon can change the viewpoint by switching camera output without physically moving the camera. Using eight camera's images, we also tried to reconstruct 3D textured shape of the surgery field.

Noninvasive assessment of intra-abdominal pressure by measurement of abdominal wall tension.

BACKGROUND: Sustained increased intra-abdominal pressure (IAP) has negative effects. Noninvasive IAP measurement could be beneficial to improve monitoring of patients at risk and in whom IAP measurements might be unreliable. We assessed the relation between IAP and abdominal wall tension (AWT) in vitro and in vivo. MATERIALS AND METHODS: The abdomens of 14 corpses were insufflated with air. IAP was measured at intervals up to 20 mm Hg. At each interval, AWT was measured five times at six points. In 42 volunteers, AWT was measured at five points in supine, sitting, and standing positions during various respiratory manoeuvres. Series were repeated in 14 volunteers to measure reproducibility by calculating coefficients of variation (CV). ANOVA was used for analyses. RESULTS: In corpses, all points showed significant correlations between IAP and AWT (P < 0.001 for points 1-4 in the upper abdomen, P = 0.017 for point 5 and P = 0.008 for point 6 in the lower abdomen). Mean slopes were greatest at points across the epigastric region (points 1-3). In vivo measurements showed that AWT was on average 31% higher in men compared to women (P < 0.001), and increased from expiration to inspiration to Valsalva's manoeuvre (all P < 0.001). AWT was highest at points 1 and 2 and in standing position, followed by supine and sitting positions. BMI did not influence AWT. Mean CV of repeated measurements was 14%. CONCLUSIONS: AWT reflects IAP. The epigastric region appears most suitable for AWT measurements. Further longitudinal clinical studies are needed to assess usefulness of AWT measurements for monitoring of IAP.

Effects of propofol anaesthesia on thoraco-abdominal volume variations during spontaneous breathing and mechanical ventilation.

BACKGROUND: Anaesthesia based on inhalational agents has profound effects on chest wall configuration and breathing pattern. The effects of propofol are less well characterised. The aim of the current study was to evaluate the effects of propofol anaesthesia on chest wall motion during spontaneous breathing and positive pressure ventilation. METHODS: We studied 16 subjects undergoing elective surgery requiring general anaesthesia. Chest wall volumes were continuously monitored by opto-electronic plethysmography during quiet breathing (QB) in the conscious state, induction of anaesthesia, spontaneous breathing during anaesthesia (SB), pressure support ventilation (PSV) and pressure control ventilation (PCV) after muscle paralysis. RESULTS: The total chest wall volume decreased by 0.41 ± 0.08 l immediately after induction by equal reductions in the rib cage and abdominal volumes. An increase in the rib cage volume was then seen, resulting in total chest wall volumes 0.26 ± 0.09, 0.24 ± 0.10, 0.22 ± 0.10 l lower than baseline, during SB, PSV and PCV, respectively. During QB, rib cage volume displacement corresponded to 34.2 ± 5.3% of the tidal volume. During SB, PSV and PCV, this increased to 42.2 ± 4.9%, 48.2 ± 3.6% and 46.3 ± 3.2%, respectively, with a corresponding decrease in the abdominal contribution. Breathing was initiated by the rib cage muscles during SB. CONCLUSION: Propofol anaesthesia decreases end-expiratory chest wall volume, with a more pronounced effect on the diaphragm than on the rib cage muscles, which initiate breathing after apnoea.

A new method to estimate energy expenditure from abdominal and rib cage distances.

The aim of this paper is to validate a new method of energy expenditure (EE) estimation stemming solely from the measurement of rib cage, abdominal and chest wall distances. We set out to prove that the variations of these distances, measured by two pairs of electromagnetic coils, lead to the estimation of the ventilation (VE) and the EE. Eleven subjects were recruited to take part in this study (27.6 ± 5.4 years; 73.7 ± 9.7 kg). Each subject participated in two tests. The objective of Test 1 was to determine the individual and group equations between the VE and EE during light to moderate activities while Test 2 compared the two pairs of electromagnetic coils with the indirect calorimetry so as to estimate EE in upright sitting and standing positions and during walking exercises. During Test 2, we compared EE measured by indirect calorimetry (EE(IC-Val-REF)) with EE estimated by the two pairs of electromagnetic coils through the application of: (1) the individual equation (EE(mag-Val-INDIV)) and (2) the group equation (EE(mag-val-GROUP)). The results show that there is no significant difference between EE(IC-Val-REF) and EE(mag-Val-INDIV) and between EE(IC-Val-REF) and EE(mag-val-GROUP) for each activity. Furthermore, the mean difference seems to show that the estimation of EE is better with the group equation. In conclusion, on the proven basis of this study we are able to validate this new method which permits the estimation of EE from abdominal and rib cage distances. This study also highlights the advantage of using a group equation to the estimate EE.

The effect of food consumption on the thickness of abdominal muscles, employing ultrasound measurements.

Recently, the roles of transabdominal muscles particularly TrA (transverse abdominis) muscle in spinal stability leading to treatment of low back pain have been suggested. Both in clinical setting and follow up studies, abdominal muscle thickness measurements need to be repeated at a later point in time to demonstrate efficacy of a therapeutic intervention. Different issues have been suggested as source of error in the repeated measurements of abdominal muscle thickness in different days such as patient position and stability of probe location. The level of stomach fullness has not been investigated as a source of error in ultrasonic measurements of transabdominal muscles thickness. This study was performed to evaluate the effect of food consumption on thickness of lateral abdominal muscles. Lateral abdominal muscles thicknesses of 63 healthy volunteer men were measured before and after food consumption. All the measurements were performed in two transducer positions and both sides. Waist circumference and body weight of participants were also measured before and post-food consumption. The thickness measures of all three muscles layers of lateral abdominal muscles (external oblique, internal oblique and transversus abdominis) in both sides and measured positions were significantly reduced after food consumption. We found no correlation between the increase of waist circumference and reduction of muscle layer thicknesses after food consumption. In case of comparison between the values of transabdominal muscle thicknesses over the time, the effect of food consumption on muscle thickness might be assumed as a potential source of error.

Intra-abdominal pressure measurement method via the urinary-tube: bedside validation of a biomechanical model integrating urine column height and bladder urinary volume.

BACKGROUND: The objective of this work was to demonstrate the possibility of accurately measuring intra-abdominal pressure (IAP) by using a common urine drainage bag (U-Tube) as a hydrostatic column of measurement. This has been done by integrating urine column height (h) and bladder urinary volume (BUV) in the IAP measurement method. METHOD: Seventy-eight newly admitted patients in a 22 bed university hospital intensive care unit (ICU) were studied. Two U-Tube IAP measurement methods were compared with the "Gold-standard" closed-system repeated measurement technique with bladder pressure transducer: U-Tube method I, where h (in cm) alone assesses IAP (in cm H2O) and U-Tube method II, integrating BUV according to a basic biomechanical model of bladder wall compliance to give a more accurate IAP estimation. RESULTS: Correlation rate using linear regression analysis was better between the Gold standard method and method II than method I with R = 0.901, P < 0.0001 and R = 0.682, P < 0.0001, respectively. For method II, Bland-Altman analysis showed a mean bias of -1.0 +/- 0.1 mm Hg (limits of agreement -3.4-1.4, percentage error +/-7.7%). Area under the receiver operator characteristics curves to screen intra-abdominal hypertension (IAP >or=12 mm Hg) was significantly greater with method II than with method I: 0.99 versus 0.93, P < 0.05; sensitivity and specificity of method II were 95% and 98%, respectively. CONCLUSION: By integrating urine column height and BUV in the measurement method, it may be conceivable to screen IAH at the bedside via a U-Tube in ICU; bladder wall compliance should be estimated to avoid the emergence of false-positive subjects due to the possible occurrence of bladder wall compliance alteration before or during the ICU stay.

Effect of elevated intra-abdominal pressure on portal vein and superior mesenteric artery blood flow in a rat.

AIM: Recent clinical experience suggests that minimal access portoenterostomy (the Kasai procedure) for biliary atresia leads to transplantation sooner, compared to the traditional open approach. It should be emphasized that elevated intra-abdominal pressure (IAP) may reduce hepatic and portal blood flow and thus may cause histologic liver damage. The aim of the present study was to evaluate the effects of IAP on blood flow in the portal vein (PV), compared to the superior mesenteric artery (SMA), and on the systemic mean arterial blood pressure (MABP). MATERIALS AND METHODS: Male Sprague-Dawley rats were anesthetized with intraperitoneal ketamine (90 mg per kg) and xylasine (13 mg per kg). Polyethylene catheters (PE-50) were introduced into the right carotid artery for the measurement of MABP. After a midline laparotomy, the SMA and PV were isolated. Ultrasonic blood-flow probes were placed on the vessels for the continuous measurement of regional blood flow. Two large-caliber percutaneous peripheral intravenous catheters were introduced into the peritoneal cavity for inflation of air and for the measurement of IAP. The time course of MABP and SMA and PV flow as well as the relationship between IAP and SMA and PV flow were determined. RESULTS: Although all three hemodynamic parameters decreased with the increase in the IAP, the most significant changes were observed in PV blood flow. IAP at 3 mm Hg resulted in a 26% decrease in PV flow (P < 0.05), a 19% decrease in SMA flow (P < 0.05), and an 11% decrease in MABP (P < 0.05). IAP at 6 mm Hg caused a two-fold decrease in PV flow (P < 0.05), a 30% decrease in SMA flow (P < 0.05), and a 19% decrease in MABP (P < 0.05). There were no changes in the time course of MABP and PV and SMA flow. PV and SMA flow returned to normal values immediately after abdominal deflation. CONCLUSIONS: Persistent IAP decreased MABP, SMA, and, especially, PV flow by 50%. We speculate that in biliary atresia patients with already present liver dysfunction, decrease in SMA flow and even a greater decrease in PV flow from increased IAP, which occurs during a laparoscopic Kasai procedure, may further compromise liver function. This may be one of the explanations for the progression to earlier transplantation in infants undergoing a laparoscopic Kasai procedure.

The Relationship Between Intra-Abdominal Pressure and Body Acceleration During Exercise.

OBJECTIVES: High intra-abdominal pressure (IAP) may influence the development of pelvic floor disorders. We and others have used intravaginal pressure transducers to measure IAP in women during exercise and daily activities, but utilizing the transducer for long-term measurements creates compliance issues. Waist-worn accelerometers are prominent in research and may be a reliable alternative for approximating IAP. We hypothesized that there are pair-wise positive correlations between the mean maximal accelerometer vector magnitude and 2 IAP measurements: mean maximal IAP and area under the curve (AUC). METHODS: Twenty-five women who regularly participated in exercise performed 13 activities. Intra-abdominal pressure was measured with an intravaginal transducer and acceleration with a waist-worn accelerometer. We determined the mean maximal IAP, AUC for IAP, and mean maximal accelerometer vector magnitude for each activity and participant. The relationship between IAP and acceleration was determined by computing the Pearson correlation coefficient (R) and the 95% confidence interval for mean maximal accelerometer vector magnitude versus mean maximal IAP and mean maximal accelerometer vector magnitude versus AUC for IAP. RESULTS: The R values were 0.7353 for mean maximal accelerometer vector magnitude versus mean maximal IAP (including walking) and 0.5059 for mean maximal accelerometer vector magnitude versus AUC for IAP (excluding walking). Walking at 3 speeds, analyzed separately, presented R values of 0.72208 for mean maximal IAP and 0.21678 for AUC. CONCLUSION: Waist-worn accelerometers may provide a viable method for approximating mean maximal IAP in a population of women during most activities.