A Single-Lumen Central Venous Catheter for Continuous and Direct Intra-abdominal Pressure Measurement

Background: Abdominal compartment syndrome (ACS) is associated with high morbidity and mortality rates. Therefore, the need for a good diagnostic tool to predict intra-abdominal hypertension (IAH) and progression to ACS is paramount. Bladder pressure (BP) has been used for several years for intra-abdominal pressure (IAP) measurement but has the disadvantage that it is not a continuous measurement. In this study, a single-lumen central venous catheter (CVC) is placed through the abdominal wall into the abdominal cavity to continuously and directly monitor the intra-abdominal pressure (CDIAP). The aim of this study was to evaluate the use of CDIAP to measure BP as a representative of the true IAP. Methods: Both BP and CDIAP were prospectively recorded on a variety of surgical patients admitted to the intensive care unit (ICU) from March 2003 up to December 2004. At the end of the surgical procedure, the CVC was placed through the abdominal wall and connected to a pressure transducer. In addition, the BP was measured through the urine drainage port after clamping the catheter and filling the bladder with 50 ml of 0.9% saline. At least three paired measurements (BP and CDIAP) were performed for at least one day on the ICU in a standardized manner at preset time intervals on each patient. The paired measurements were compared using the Bland-Altman (B-A) method. Data are presented as mean ± standard deviation. Results: Over a period of 22 months (March 2003 until December 2004), 125 paired measurements of both BP and CDIAP were recorded on 25 patients. The mean age was 72.4 ± 6.6 years. Eighteen patients underwent central vascular surgery, and seven patients with peritonitis received laparotomy. The mean CDIAP was 11.4 ± 4.8 (range 2-30) mmHg, and the BP was 12.9 ± 5.3 (range 3-37) mmHg. The mean difference between CDIAP and BP was 1.6 ± 2.7 mmHg. There was an acceptable level of agreement (intraclass correlation 0.82) between IAP measured by BP and IAP measured via CDIAP. Conclusion: Continuous direct intra-abdominal pressure measurement proved that the BP measurement approach of Kron is representative of the IAP. CDIAP measurement is accurate and makes it easier for the nursing staff to be informed of the IAP

[Accepted Manuscript] Left Main Revascularization With PCI or CABG in Patients With Chronic Kidney Disease: EXCEL Trial.

The optimal revascularization strategy for patients with left main coronary artery disease (LMCAD) and chronic kidney disease (CKD) remains unclear. This study investigated the comparative effectiveness of percutaneous coronary intervention (PCI) versus coronary artery bypass graft (CABG) surgery in patients with LMCAD and low or intermediate anatomical complexity according to baseline renal function from the multicenter randomized EXCEL (Evaluation of XIENCE Versus Coronary Artery Bypass Surgery for Effectiveness of Left Main Revascularization) trial. CKD was defined as an estimated glomerular filtration rate <60 ml/min/1.73 m2 using the CKD Epidemiology Collaboration equation. Acute renal failure (ARF) was defined as a serum creatinine increase ≥5.0 mg/dl from baseline or a new requirement for dialysis. The primary composite endpoint was the composite of death, myocardial infarction (MI), or stroke at 3-year follow-up. CKD was present in 361 of 1,869 randomized patients (19.3%) in whom baseline estimated glomerular filtration rate was available. Patients with CKD had higher 3-year rates of the primary endpoint compared with those without CKD (20.8% vs. 13.5%; hazard ratio [HR]: 1.60; 95% confidence interval [CI]: 1.22 to 2.09; p = 0.0005). ARF within 30 days occurred more commonly in patients with compared with those without CKD (5.0% vs. 0.8%; p < 0.0001), and was strongly associated with the 3-year risk of death, stroke, or MI (50.7% vs. 14.4%; HR: 4.59; 95% CI: 2.73 to 7.73; p < 0.0001). ARF occurred less commonly after revascularization with PCI compared with CABG both in patients with CKD (2.3% vs. 7.7%; HR: 0.28; 95% CI: 0.09 to 0.87) and in those without CKD (0.3% vs. 1.3%; HR: 0.20; 95% CI: 0.04 to 0.90; pinteraction = 0.71). There were no significant differences in the rates of the primary composite endpoint after PCI and CABG in patients with CKD (23.4% vs. 18.1%; HR: 1.25; 95% CI: 0.79 to 1.98) and without CKD (13.4% vs. 13.5%; HR: 0.97; 95% CI: 0.73 to 1.27; pinteraction = 0.38). Patients with CKD undergoing revascularization for LMCAD in the EXCEL trial had increased rates of ARF and reduced event-free survival. ARF occurred less frequently after PCI compared with CABG. There were no significant differences between PCI and CABG in terms of death, stroke, or MI at 3 years in patients with and without CKD. (EXCEL Clinical Trial [EXCEL]; NCT01205776)

Effect of increased intra-abdominal pressure and decompressive laparotomy on aerated lung volume distribution

Increased intra-abdominal pressure (IAP) is common in intensive care patients, affecting aerated lung volume distribution. The current study deals with the effect of increased IAP and decompressive laparotomy on aerated lung volume distribution. The serial whole-lung computed tomography scans of 16 patients with increased IAP were retrospectively analyzed between July 2006 and July 2008 and compared to controls. The IAP increased from (12.1±2.3) mmHg on admission to (25.2±3.6) mmHg (P<0.01) before decompressive laparotomy and decreased to (14.7±2.8) mmHg after decompressive laparotomy. Mean time from admission to decompressive laparotomy and length of intensive-care unit (ICU) stay were 26 h and 16.2 d, respectively. The percentage of normally aerated lung volume on admission was significantly lower than that of controls (P<0.01). Prior to decompressive laparotomy, the total lung volume and percentage of normally aerated lung were significantly less in patients compared to controls (P<0.01), and the absolute volume of non-aerated lung and percentage of non-aerated lung were significantly higher in patients (P<0.01). Peak inspiratory pressure, partial pressure of carbon dioxide in arterial blood, and central venous pressure were higher in patients, while the ratio of partial pressure of arterial O2 to the fraction of inspired O2 (PaO2/FIO2) was decreased relative to controls prior to laparotomy. An approximately 1.8 cm greater cranial displacement of the diaphragm in patients versus controls was observed before laparotomy. The sagittal diameter of the lung at the T6 level was significantly increased compared to controls on admission (P<0.01). After laparotomy, the volume and percentage of non-aerated lung decreased significantly while the percentage of normally aerated lung volume increased significantly (P<0.01). In conclusion, increased IAP decreases total lung volume while increasing non-aerated lung volume. Decompressive laparotomy is associated with resolution of these effects on lung volumes