GABAergic and glutamatergic transmission reveals novel cardiovascular and urinary bladder control features in the shell nucleus accumbens

The shell Nucleus Accumbens (NAcc) projects to the lateral preoptic area, which is involved in the central micturition control and receives inputs from medullary areas involved in cardiovascular control. We investigated the role of GABAergic and glutamatergic transmission in the shell NAcc on intravesical pressure (IP) and cardiovascular control. Male Wistar rats with guide cannulas implanted bilaterally in the shell NAcc 7 days prior to the experiments were anesthetized with 2% isoflurane in 100% O2 and subjected to cannulation of the femoral artery and vein for mean arterial pressure (MAP) and heart rate recordings (HR) and infusion of drugs, respectively. The urinary bladder (UB) was cannulated for IP measurement. A Doppler flow probe was placed around the renal arterial for renal blood flow (RBF) measurement. After the baseline MAP, HR, IP and RBF recordings for 15 min, GABA or bicuculline methiodate (BMI) or L-glutamate or kynurenic acid (KYN) or saline (vehicle) were bilaterally injected into the shell NAcc and the variables were measured for 30 min. Data are as mean ± SEM and submitted to Student́s t test. GABA injections into the shell NAcc evoked a significant fall in MAP and HR and increased IP and RC compared to saline. L-glutamate in the shell NAcc increased MAP, HR and IP and reduced RC. Injections of BMI and KYN elicited no changes in the variables recorded. Therefore, the GABAergic and glutamatergic transmissions in neurons in the shell NAcc are involved in the neural pathways responsible for the central cardiovascular control and UB regulation.

Management of abdominal compartment syndrome in acute pancreatitis

Abdominal compartment syndrome (ACS), defined by the presence of increased intra-abdominal pressure>20mmHg in association with failure of at least one organ system, is a common and feared complication that may occur in the early phase of severe acute pancreatitis (AP). This complication can lead to patient death in the very short term. The goal of this review is to provide the surgeon and intensivist with objective information to help them in their decision-making. In the early phase of severe AP, it is essential to monitor intra-vesical pressure (iVP) to allow early diagnosis of intra-abdominal hypertension or ACS. The treatment of ACS is both medical and surgical requiring close collaboration between the surgical and resuscitation teams. Medical treatment includes vascular volume repletion, prokinetic agents, effective curarization and percutaneous drainage of large-volume ascites. If uncontrolled respiratory or cardiac failure develops or if maximum medical treatment fails, most teams favor performing an emergency xipho-pubic decompression laparotomy with laparostomy. This procedure follows the principles of abbreviated laparotomy as described for abdominal trauma.

Relevance of intravesical pressures during transurethral procedures

PURPOSE

Endourology has undergone fundamental changes over the last 2 decades. Maintaining low intrarenal pressure (IRP) during upper urinary tract procedures is an established concept. However, researchers have not yet studied the concept of reduced intravesical pressures (IVPs) during transurethral (TUR) surgery as thoroughly. Low IVP is supposed to decrease complications as fluid retention, TUR syndrome, and incidence of fever. The study aims to give an overview of the contemporarily existing concepts and specify the term of low IVP to avoid TUR-related complications and optimize TUR-related results.

METHODS

A literature search was performed using PubMed, restricted to original English-written articles, including animal, artificial model, and human studies. Different keywords were transurethral resection, transurethral enucleation, transurethral vaporization, pressure, fluid absorption, and TUR syndrome.

RESULTS

Analyzed mean IVPs during TUR vary between 11 and 35 cmH₂O but are mostly kept below 30 cmH₂O. Mean maximum IVPs during TUR range from 20 to 55 cmH₂O. Maximum IVPs seem to be lower when surgeons utilize continuous flow resection, and irrigation pressures are kept low. The results demonstrate a strong correlation between IVP levels and fluid absorption.

CONCLUSIONS

IVP increase remains a neglected predictor of transurethral procedure complications, and endourologists should consider its intraoperative monitoring. Further research is necessary to quantify generated pressures and introduce means of controlling them.

Abdominal compartment syndrome monitoring in neonates with an acute abdomen - A pilot, retrospective, observational study

BACKGROUND

Abdominal compartment syndrome (ACS) is a pathological increase of the intra-abdominal pressure (IAP) with dysfunction of one or more organs. There is lack of clarity in neonates regarding what intravesical pressure (IVP) value, a surrogate marker for IAP, indicates the need for intervention for ACS.

METHODS

The medical records at a Children's Hospital NICU were reviewed to identify all neonates that had IVP/s monitored over a 10-year period (2008-2017). Demographic parameters, IVPs, and important clinical outcomes were obtained. Associations between IVP monitoring and clinical outcomes were explored.

RESULTS

Forty-six neonates had IVP monitoring, with 4 (8%) being diagnosed with ACS requiring further operative intervention. There was no significant correlation between IVP and need for surgery. There was a significant positive correlation between the maximum IVP and the need for total parenteral nutrition (rs = 0.350, p = 0.017), ventilator support (rs = 0.321, p = 0.034) and length of stay (rs = 0.362, p = 0.016) and between a diagnosis of ACS and neonatal mortality (rs = 0.299, p = 0.044).

CONCLUSIONS

IVP monitoring and raised IVP did not correlate with the need for surgical intervention. Raised IVP was associated with neonatal morbidity and maybe neonatal mortality. A large, prospective, observational study is required to evaluate the role of IVP monitoring in ACS and its associated outcomes.

LEVEL OF EVIDENCE

III.

[How to explain glomerular filtration rate decrease in intra-abdominal hypertension?]

Intra-abdominal hypertension (IAH) is a frequent and serious condition affecting critical care patients. IAH diagnostic needs intravesical pressure (IVP) measurement which is recommended for monitoring patients presenting IAH risk factors. IVP monitoring is probably insufficient in daily practice. This could be explained by lack of knowledge about IAH physiopathology, which leads to absence of therapeutic target. Acute kidney injury (AKI) is the earliest and most described organ dysfunction associated with IAH. Moreover, AKI gravity seems to correlates with IAH severity. Physiopathological aspects explaining glomerular filtration rate (GFR) decrease with IAH are probably multifactorial and not completely understood. The role of renal venous congestion is essential to explain AKI in IAH. GFR decrease may reflect a "glomerular capillary shunt" due to a decrease of renal plasmatic flow. Monitoring IVP in daily practice in patients presenting risk factors of IAH would improve knowledge about this condition and the associated AKI.

Incidence and prognosis of intraabdominal hypertension and abdominal compartment syndrome in children

PURPOSE

Intraabdominal hypertension (IAH) and abdominal compartment syndrome (ACS) are associated with high mortality rates in children (40-60%). However, literature lacks comprehensive series in childhood. In this study, we aimed to determine the incidences of IAH and ACS, to identify high risk disorders for the development of IAH/ACS and to decrease ACS-associated mortality by early diagnosis and timely intervention.

METHODS

A prospective study was performed between December 2009 and October 2010 in our institution. IAH was defined by a sustained or repeated pathological elevation in IAP≥12mmHg without a new organ failure. ACS was identified as a sustained IAP>15mmHg with a new organ dysfunction/failure. After recognition of IAH or ACS, patients underwent prompt decompressive interventions as medical or surgical procedures.

RESULTS

150 patients were enrolled to the study (86 M, 64 F). The incidences of IAH and ACS were 9% and 4%, respectively. High risk disorders were trauma, ileus, necrotizing enterocolitis, abdominal wall defects, diaphragmatic hernia and septic shock with massive fluid resuscitation. 14 patients with IAH were treated and mean IAP was decreased from 13.9±1.9mmHg to 9.2±2.1mmHg (p<0.001). None of them progressed to ACS. Six patients with ACS underwent decompressive laparotomy. Mean IAP decreased significantly from 20±3mmHg to 9±1.4mmHg (p=0.001). Vital signs like mean urine output, abdominal perfusion pressure (APP) and respiratory rate were significantly improved after surgery (p<0.05). ACS-associated mortality rate was determined as 16%.

CONCLUSIONS

IAH or ACS was occurred in nearly one tenth of patients admitted to neonatal and pediatric intensive care units. High clinical suspect must be drawn on to recognize and treat these clinical complications more efficiently. Regular and frequent IAP measurement in high risk disorders is essential for early diagnosis. Lower mortality rates can be achieved by early recognition and timely intervention in children.

Study of intra-abdominal hypertension prevalence and awareness level among experienced ICU medical staff

BACKGROUND

Intra-abdominal hypertension (IAH) is a disease with high morbidity and mortality among critically ill patients. The study's objectives were to explore the prevalence of IAH and physicians' awareness of the 2013 World Society of Abdominal Compartment Syndrome (WSACS) guidelines in Chinese intensive care units (ICUs).

METHODS

A cross-sectional study of four ICUs in Southwestern China was conducted from June 17 to August 2, 2014. Adult patients admitted to the ICU for more than 24 h, with bladder catheter but without obvious intravesical pressure (IVP) measurement contraindications, were recruited. Intensivists with more than 5 years of ICU working experience were also recruited. Epidemiological information, potential IAH risk factors, IVP measurements and questionnaire results were recorded.

RESULTS

Forty-one patients were selected. Fifteen (36.59 %) had IVP ≥ 12 mmHg. SOFA (Sequential Organ Failure Assessment) hepatic and neurological sub-scores were utilized as independent predictors for IAH via logistic backward analysis. Thirty-seven intensivists participated in the survey (response rate: 80.43 %). The average score of each center was less than 35 points. All physicians believed the IAH prevalence in their departments was no more than 20.00 %. A significant negative correlation was observed between the intensivists' awareness of the 2013 WSACS guidelines and the IAH prevalence in each center (r = -0.975, P = 0.025).

CONCLUSIONS

The prevalence and independent predictors of IAH among the surveyed population are similar to the reports in the literature. Intensivists generally have a low awareness of the 2013 WSACS guidelines. A systematic guideline training program is vital for improving the efficiency of the diagnosis and treatment of IAH.