Influence Of Intra-abdominal Pressure Research Articles

Influence of intra-abdominal pressure on ventilatory mechanical power delivery and respiratory driving pressure during laparoscopic cholecystectomy: A prospective cohort study

Abstract Background and Aims: Pneumoperitoneum creation for laparoscopic surgery increases the intraabdominal pressure and causes alveolar atelectasis. We investigated the influence of an increase in intra-abdominal pressure (IAP) on ventilatory mechanical power (MP) delivery during pneumoperitoneum creation for laparoscopic cholecystectomy. Material and Methods: In a prospective cohort design, we enrolled 42 patients undergoing laparoscopic cholecystectomy. During pneumoperitoneum creation, the IAP was sequentially raised to three predefined IAP levels (8, 11 and 14 mmHg), keeping identical ventilatory settings (timepoints T1, T2, and T3). After that, positive end-expiratory pressure (PEEP) was sequentially raised from 5 to 8 to 11 cmH2O (timepoint T4 and T5). The primary outcome included ventilatory MP delivery at each timepoint. Other variables included respiratory driving pressure (DP), airway resistance (AR), and respiratory compliance (RC). Results: The MP increased linearly with a rise in IAP from T1 to T3 (r = 0.71, P < 0.001); the MP increased by 0.19 per unit rise in IAP (effect size 0.90, P < 0.001). A similar positive correlation was also observed between DP and IAP from T1 to T3 (r = 0.73, P < 0.001); the DP increased by 0.72 per unit rise in IAP (effect size 0.89, P < 0.001). The MP increased significantly on increasing PEEP from T3 to T5, while the DP decreased concomitantly (P < 0.001). The AR increased significantly from T1 to T3, while RC decreased concomitantly; vice-versa was observed at T4 and T5 (P < 0.001). Conclusions: The ventilatory MP delivery rises linearly with an increase in IAP. Targeting an IAP-guided MP level could be an attractive approach to minimize lung injury.

Influence of intra-abdominal pressure on the amplitude of fluctuations of cerebral hemoglobin concentration in the respiratory band

An intra-abdominal pressure (IAP) is correlated with cerebral perfusion, in a mechanism of reducing venous outflow. The elevated intra-abdominal pressure leads to an increase in the intracranial pressure and a decrease in the cerebral perfusion pressure. We studied the relationship between the IAP and the cerebral oxygenation with the use of the near infrared spectroscopy technique during a gynecological surgery. The changes in hemoglobin concentrations were analyzed in the time-frequency domain in the frequency band related to respiration. The measurements were carried out in 15 subjects who underwent laparoscopic surgery. During the laparoscopy, the intra-abdominal cavity was insufflated with CO2, which caused a controlled increase in the IAP. It was observed that the amplitudes of respiration-related waves present in hemoglobin concentration signals show an increase of 1.5 to 8.5 times during elevation of the IAP by 15 mmHg.

Oxidative damage and mitochondrial injuries differ following pneumoperitoneum pressure in rabbit models of varying degrees of hydronephrosis.

The influence of intraabdominal pressure which is necessary to maintain the operating area during the surgery cannot be ignored especially on the kidneys. Many articles have reported the effect of intraabdominal pressure on normal kidneys. However, the influence of intraabdominal pressure on hydronephrosis kidneys is rarely studied. The aim of the present study was to clarify whether intraabdominal pressure tolerance is modified in various degrees of kidney hydronephrosis by evaluating oxidative damage and mitochondrial injuries. A total of 72 rabbits were randomly divided into three groups (groups N, M and S, which represented rabbits with no, mild and severe hydronephrosis, respectively). Rabbits in groups M (n=24) and S (n=24) underwent a surgical procedure inducing mild or severe hydronephrosis, respectively. Subsequently, rabbits in all groups were allocated to 4 subgroups (N0‑N3, M0‑M3 and S0‑S3) consisting of 6 rabbits each. Groups 0 to 3 were, respectively, subjected to intraabdominal pressures of 0, 5, 10 and 15mmHg. Oxidative damage was assessed by analyzing levels of reactive oxygen species (ROS), superoxide dismutase (SOD), malondialdehyde (MDA), glutathione peroxidase (GSH‑Px), catalase (CAT) and lactate (LD). Mitochondrial injuries were assessed based on mitochondrial membrane potential (MMP) alterations, mitochondrial structure and cytochrome c (cytc) protein expression, as measured by JC‑1 staining, electron microscopy and western blotting, respectively. Oxidative damage and mitochondrial injuries were noticeably exacerbated in group N and M with increased levels of ROS, MDA and LD, decreased levels of SOD, GSH‑Px, CAT and MMP, mitochondrial vacuolization and higher expression of cytc when the intraabdominal pressure reached 15mmHg. In group S, these alterations occurred at pressures of 10 and 15mmHg. Therefore, it was concluded that in rabbits exposed to pneumoperitoneal pressure, kidneys with severe hydronephrosis were more likely to suffer from oxidative damage and mitochondrial injuries compared with kidneys with mild hydronephrosis and normal kidneys.

The influence of intraabdominal pressure on the mortality rate of patients with acute pancreatitis.

Intraabdominal hypertension (IAH) is a common clinical finding in patients with acute pancreatitis and is associated with poor prognosis. This study aimed to determine the impact of intraabdominal pressure (IAP) on the mortality rate in patients with acute pancreatitis in an intensive care unit. A total of 50 patients with acute pancreatitis were included in this prospective cohort study. Based on the obtained values of IAP, the patients were divided into two groups: those with normal IAP (n = 14) and increased IAP (n = 36). Mean values of IAP were compared with examined variables. The mortality rate of the study group was 40%. Comparing the IAP and treatment outcomes, it was proved that there were statistically highly significant differences (P = 0.012). Increasing the value of IAP increased the mortality rate. Deceased patients in the IAH group had greater statistical significance of APACHE II score (P = 0.016), abdominal perfusion pressure (P = 0.048), lactate (P = 0.049), hematocrit (P = 0.039), Ranson's criteria on admission (P = 0.017), Ranson's criteria after 48 h (P = 0.010), Sequential Organ Failure Assessment score (P = 0.014), and body mass index (P = 0.012) compared to the surviving patients. IAP has an impact on the increase of mortality rates in patients with acute pancreatitis.

Pilot Study of the Influence of Intra-Abdominal Pressure of Parturient Women with Obesity on the Neurologic Status of a Newborn

Introduction: Given in the literature, there is a possible link between perinatal pathology and intra-abdominal pressure (IAP) in pregnant women. Since intra-abdominal hypertension (IAH) is the companion of obesity, we can assume that there is a casual relation of perinatal complications of high frequency which obese patients with a level of IAP have. Methods: A pilot study involving 407 patients: 135 of those were patients with the spontaneous labor, 273 were patients with the abdominal delivery. Patients, depending on their body mass index (BMI) were divided into four groups: group I - control (n=117), group II - patients with I degree of obesity (n=158), group III - with II degree of obesity (n=84), group IV - with III degree of obesity (n=48). The groups were divided into subgroups according to the neurological status of a newborn. IAP research was carried out using the indirect method through the bladder. The assessment of mental status of the newborn was performed with the help of NACS scale. Results: The frequency and severity of the neurological deficit in newborns depended on the level of IAP before delivery and IAP in delivery. The correlational analysis of the degree of asphyxia and neonatal neurologic status is the presence of an average bond strength (r=-0.66, p<0.001). In subgroups where the epidural analgesia was introduced during labor, the overall score on NACS scale was significantly higher (p<0.001). In the groups of patients with severe obesity, the total score on the NACS scale was significantly lower (p<0.05) compared with other methods of anesthesia. Conclusion: The results of the limited pilot study indicate the impact of the level of IAP of parturient women with obesity on the severity of asphyxia and the neurological status of the newborn in the early neonatal period.

Вплив внутрішньочеревного тиску на перебіг хронічних колостазів у дітей

Вплив внутрішньочеревного тиску на перебіг хронічних колостазів у дітей

Mild to moderate intra-abdominal hypertension: Does it matter?

This review summarizes the epidemiology, pathophysiological consequences and impact on outcome of mild to moderate (Grade I to II) intra-abdominal hypertension (IAH), points out possible pitfalls in available treatment recommendations and focuses on tasks for future research in the field. IAH occurs in about 40% of ICU patients. Whereas the prevalence of abdominal compartment syndrome seems to be decreasing, the prevalence of IAH does not. More than half of IAH patients present with IAH grade I and approximately a quarter with IAH grade II. However, most of the studies have addressed IAH as a yes-or-no variable, with little or no attention to different severity grades. Even mild IAH can have a negative impact on tissue perfusion and microcirculation and be associated with an increased length of stay and duration of mechanical ventilation. However, the impact of IAH and its different grades on mortality is controversial. The influence of intra-abdominal pressure (IAP) on outcome most likely depends on patient and disease characteristics and the concomitant macro- and microcirculation. Therefore, management might differ significantly. Today, clear triggers for interventions in different patient groups with mild to moderate IAH are not defined. Further studies are needed to clarify the clinical importance of mild to moderate IAH identifying clear triggers for interventions to lower the IAP.

Intra-abdominal pressure and possible ways of its drug correction after emergency laparotomy

Intra-abdominal pressure and possible ways of its drug correction after emergency laparotomy

Influence of intra-abdominal pressure on the specificity of pulse pressure variations to predict fluid responsiveness

The positive predictive value of pulse pressure variations (ΔPP) to discriminate patients who should respond to volume expansion (VE) may be altered in mechanically ventilated patients. Our goal was to determine whether intra-abdominal pressure (IAP) measurements could discriminate patients with true-positive ΔPP values versus patients with false-positive ΔPP values. We designed a prospective pathophysiologic study in a mixed intensive care unit of a university hospital. Sixteen mechanically ventilated patients with hypotension (SAP, <90 mm Hg) and with ΔPP of 13% or more were included. Cardiac output was assessed using Doppler echocardiography before and after VE; IAP was measured using the bladder pressure method. Patients were classified into two groups according to their response to a standardized VE (500 mL of NaCl 0.9%): responders (≥15% increase in cardiac output) and nonresponders. Nine patients (57%) were responders, and seven patients (43%) were nonresponders. Before VE, IAP was statistically higher in nonresponders (15 [11-22] mm Hg vs. 9 [6.5-11] mm Hg; p = 0.008). The area under the curve of the receiver operating characteristic curve was 0.9 ± 0.08. In patients with ΔPP of 13% or more, an IAP cutoff value of 10.5 mm Hg discriminated between responders and nonresponders with a sensitivity of 100% (59-100%) and a specificity of 78% (40-97%). An increase in IAP of more than 10.5 mm Hg can decrease the positive predictive value of ΔPP. Hence, in patients prone to present abnormal IAP values, IAP should be measured before performing VE directed by the ΔPP marker. Diagnostic study, level II.

Design and development of a novel intra-vaginal pressure sensor

The influence of intra-abdominal pressure (IAP) on prolapse development is poorly understood. Nonetheless, chronic cough, high BMI, or heavy lifting predisposes women to pelvic organ prolapse (POP). This study aims to develop and test a novel, wireless intra-vaginal pressure sensor (IVPS) to quantify intra-abdominal pressure changes across a range of well-defined activities. The IVPS shape was based on silicone moulds of the vagina and was designed to sit in the proximal vagina. It is thin, compliant and negligibly distorts the surrounding tissues. Repeatability was assessed in 14 volunteers performing three sets of activities (cycles). Each cycle consisted of 18 activities. The IVPS was removed and reinserted after completing either the first or second of the three-cycle exercise routine (order). Participants independently inserted and removed the device. A nested split-plot, factorial ANOVA determined the effect of order using mean IAP increase (mean) and peak-to-peak fluctuations in IAP (amplitude) as dependent variables. Descriptive analysis examined the relative change in IAP across the activities. Cronbach's alpha) determined repeatability. All women found the IVPS comfortable and easy to insert. There was excellent correlation between cycles across all variables, r > 0.935 (mean) and r > 0.964 (amplitude). The order was not statistically significant, demonstrating a highly repeatable measurement. This is the first device to measure IAP at high frequency with the freedom of a wireless system. The IVPS aims to provide information to advise women better on suitable pre- and post-operative activities.

Comparison of superior vena cava and femoroiliac vein pressure according to intra-abdominal pressure

BackgroundPrevious studies have shown a good agreement between central venous pressure (CVP) measurements from catheters placed in superior vena cava and catheters placed in the abdominal cava/common iliac vein. However, the influence of intra-abdominal pressure on such measurements remains unknown.MethodsWe conducted a prospective, observational study in a tertiary teaching hospital. We enrolled patients who had indwelling catheters in both superior vena cava (double lumen catheter) and femoroiliac veins (dialysis catheter) and into the bladder. Pressures were measured from all the sites, CVP, femoroiliac venous pressure (FIVP), and intra-abdominal pressure.ResultsA total of 30 patients were enrolled (age 62 ± 14 years; SAPS II 62 (52–76)). Fifty complete sets of measurements were performed. All of the studied patients were mechanically ventilated (PEP 3 cmH20 (2–5)). We observed that the concordance between CVP and FIVP decreased when intra-abdominal pressure increased. We identified 14 mmHg as the best intra-abdominal pressure cutoff, and we found that CVP and FIVP were significantly more in agreement below this threshold than above (94% versus 50%, P = 0.002).ConclusionsWe reported that intra-abdominal pressure affected agreement between CVP measurements from catheter placed in superior vena cava and catheters placed in the femoroiliac vein. Agreement was excellent when intra-abdominal pressure was below 14 mmHg.

AO-20. Influence of intra-abdominal pressure (IAP) on changes of lung's mechanical characteristics during all periods of viscera-abdominal disproportion correction in newborns

About 10% of healthy newborns develop an unconjugated serum bilirubin level of more than 12.9 mg/dL (220 μmol/L) in early neonatal period which can be a cause for concern because unconjugated bilirubin is neurotoxic. Early and frequent feeding helps in preventing unconjugated hyperbilirubinemia. The aimwas to determine what proportion of healthy hyperbilirubinemic exclusively breastfed term neonates exhibit an insufficient milk intake.

The influence of Intra-abdominal pressure of carbon dioxide on pregnancy outcome and malformation ratio in pregnant rats

Objective To study the influence of carbon dioxide pneumoperitoneum on the pregnancy outcome and newborn rat malformation in pregnancy rats. Methods SD rats were randomly divided into control group (group A and group B) and the experimental group (group C; group D; group E). There were 10 rats in each group, the general situation,abortion rate, premature delivery rate,newborn rats numbers,weights and lengths and malformation rates were recorded. Results There was no malformation in newborn rats in all groups (P > 0. 05 ). Conclusion It was safe to undergo laparoscope operation in metaphase pregnancy with low CO2 pneumoperitoneum,which has no influence on abortion rate and malformation rate. Key words: Pneumoperitoneum, artificial; Gestational; Pregnancy outcome; Rats

Peritoneal Fibrinolytic Response to Various Aspects of Laparoscopic Surgery: A Randomized Trial

Peritoneal fibrinolysis is important in peritoneal wound healing processes and adhesion formation. The peritoneal fibrinolytic response to laparoscopy is merely unknown. In the present study we investigate the effect of short-term laparoscopy on the peritoneal fibrinolytic response and the influence of intra-abdominal pressure, light intensity and choice of dissection device on this response. There were 50 patients scheduled for laparoscopic cholecystectomy randomized in five groups operated with various pressures, light intensities, and dissection devices. Peritoneal biopsies were taken at the beginning and the end of the procedure. Tissue concentrations of tissue-type plasminogen activator (tPA), urokinase-type plasminogen activator (uPA), plasminogen activator inhibitor type 1 (PAI-1), and the tPA-activity were measured using ELISA techniques. There were no differences in tPA antigen, tPA-activity, uPA antigen, or PAI-1 antigen concentrations in biopsies taken at the beginning compared to samples taken at the end of the operation. Different intra-abdominal pressures, light intensities and the choice dissection device did not affect any of the measured parameters. Short-term laparoscopy does not affect the peritoneal fibrinolytic activity. The used intra-abdominal pressure, light intensity and choice of dissection device do not affect peritoneal activity during short-term laparoscopy.

Mechanisms of early decrease in systemic vascular resistance after total paracentesis: influence of flow rate of ascites extraction.

An early decrease in systemic vascular resistance (SVR) after total paracentesis has been observed in ascitic patients who developed paracentesis-induced circulatory dysfunction. To investigate the mechanisms of early changes in SVR after total paracentesis and the influence of intra-abdominal pressure and the flow rate of ascites extraction on the development of an early decrease in SVR. Twenty-two cirrhotic patients with tense ascites were treated by total paracentesis (7 +/- 0.4 l). Measurements of intra-abdominal pressure and the volume of ascites removed were recorded every 10 min. Hormonal and haemodynamic measurements were performed at baseline and 3 h after total paracentesis. SVR decreased 3 h after paracentesis in 17 patients and remained stable in five patients. Patients with a decrease in SVR showed a significant increase in nitrite/nitrate serum values (4.4 +/- 0.9 to 7.4 +/- 1 nmol/ml; P < 0.05). A significant correlation was observed between the decrease in SVR and nitrite/nitrate serum values (r = 0.566; P < 0.05). The volume of ascites removed was similar in patients with and without a decrease in SVR. Patients with a decrease in SVR showed higher baseline intra-abdominal pressure, shorter duration of paracentesis (60 +/- 4.9 vs 88 +/- 0.4 min; P < 0.01) and higher flow rate of ascites extraction (1.18 +/- 0.08 vs 0.81 +/- 0.12 l/min; P < 0.05). Our results confirm that an early decrease in SVR after total paracentesis is due to an increase in arterial vasodilation that may be related to an abrupt decrease in intra-abdominal pressure after fast paracentesis. Haemodynamic disturbances after total paracentesis could be prevented by reducing the flow rate of ascites extraction.

Biomechanical analysis and assessment of lumbar stress during load lifting using a dynamic 19-segment human model.

A dynamic biomechanical human model is presented which allows the quantification of mechanical parameters such as torque, compressive and shear forces, and pressure at the lumbar intervertebral discs. The human model comprises a total of 19 body segments. Various trunk flexions can be analysed due to the provision of 5 joints at the level of the 5 lumbar intervertebral discs. The influence of intraabdominal pressure on spinal load is considered. The inclusion of the influences of gravity and inertia permits the analysis of both static body postures and dynamic body movements. Since the model is 3-dimensional, the lumbar stress can be calculated during both symmetrical tasks in the median sagittal plane as well as during non-symmetrical ones. The influences on spinal stress of trunk inclination and the position of an external load relative to the body are quantified for various load weights up to 50 kg. The torque at the lumbo-sacral joint L5-S1 lies, dependent on posture and load lever-arm, within the range between 0 and 500 Nm; the compressive force on L5-S1 lies within the range between 0.4 and 10 kN, and the shear force at L5-S1 between 0.2 and 0.9 kN. The influences of lift velocity and jerky movement on lumbar stress are quantified. Simulated humpback and hollow-back postures are studied. The compressive forces at the 5 lumbar intervertebral discs are compared. The validity of the model is examined by comparing the model calculations with the intradiscal pressure measurements taken from the literature. Strength tests on lumbar intervertebral discs and vertebrae are collated from the literature in order to assess the lumbar stress during load lifting. The lumbar ultimate compression strength varies within a wide range. The mean value for a total of 307 lumbar segments amounts to 4.4 kN, the standard deviation to 1.9 kN. In conclusion, lumbar compressive force values during lifting fall within the same range as the strength values for the human lumbar spine.