Background In critically ill children, detection of intra-abdominal hypertension (IAH > 10 mmHg) and abdominal compartment syndrome (ACS = IAH + organ dysfunction) is paramount and usually monitored through intra-vesical pressures (IVP) as current standard. IVP, however, carries important disadvantages, being time-consuming, discontinuous, with infection risk through observer-dependent manipulation, and ill-defined for catheter sizes. Therefore, we sought to validate air-capsule-based measurement of intra-gastric pressure (ACM-IGP). Methods We prospectively compared ACM-IGP with IVP both in vivo and in vitro (water column), according to Abdominal-Compartment-Society validation criteria. We controlled for patient age, admission diagnosis, gastric filling/propulsive medication, respiratory status, sedation levels and transurethral catheters, all influencing intra-abdominal pressure (IAP). Results In tertiary care PICU setting, finally, n = 97 children were enrolled (median age, 1.3 years [range 0 days–17 years], LOS-PICU 8.0 [1–332] days, PRISM-III-Score 13 [0–35]). In n = 2.770 measurements pairs, median IAP was 6.7 [0.9–23.0] mmHg, n = 38 (39%) children suffered from IAH > 10 mmHg, n = 4 from ACS. In vitro against water column, ACM-IGP correlated perfectly (r2 0.99, mean bias − 0.1 ± 0.5 mmHg, limits of agreement (LOA) − 1.1/+ 0.9, percentage error [PE] 12%) as compared with IVP (r2 0.98, bias + 0.7 ± 0.6 mmHg, LOA − 0.5/+ 1.9, PE 15%). With larger IVP catheters at higher pressure levels, IVP underestimated pressures against water column. In vivo, agreement between either technique was strong (r2 0.95, bias 0.3 ± 0.8 mmHg, LOA − 1.3/+ 1.9 mmHg, PE 23%). No impact of predefined control variables on measurement agreement was observed. Conclusions In a large PICU population with high IAH prevalence, ACM-IGP agreed favourably with IVP. More widespread usage of ACM-IGP may improve detection rates of ACS in critically ill children. Trial registration WHO-ICTRP-No. DRKS00006556 (German Clinical Trial Register). Registered 12th September 2014, URL: https://www.drks.de/drks_web/navigate.do?navigationId=trial.HTML&TRIAL_ID=DRKS00006556

Background: For a long time, trans-femoral venous pressure (FVP) measurement was considered a simple alternative for estimating intra-abdominal pressure (IAP). Since intravesical [IVP] and intragastric [IGP] pressure measurements are sometimes contraindicated for anatomical and pathophysiological reasons, FVP raised hopes, especially among pediatricians. Pediatric FVP validation studies have never been published; recent results from adult studies cast doubt on their interchangeability. Therefore, we compared for the first time the measurement agreement between FVP and IVP and IGP in children. Material and methods: We prospectively compared FVP with IVP and IGP, according to the Abdominal Compartment Society validation criteria. Additionally, we analyzed the agreement as a function of IAP or right heart valve regurgitation and pulmonary hypertension. Results: In a real-life PICU study design, n = 39 children were included (median age 4.8 y, LOS-PICU 23 days, PRISM III score 11). In n = 660 FVP–IGP measurement pairs, the median IAP was 7 (range 1 to 23) mmHg; in n = 459 FVP–IVP measurement pairs, the median IAP was 6 (range 1to 16) mmHg. The measurement agreement was extremely low with both established methods (FVP–IGP: r2 0.13, mean bias −0.8 ± 4.4 mmHg, limits of agreement (LOA) −9.6/+8.0, percentage error (PE) 55%; FVP–IVP: r2 0.14, bias +0.5 ± 4.2 mmHg, limit of agreement (LOA) −7.9/+8.9, percentage error (PE) 51%). No effect of the a priori defined influencing factors on the measurement agreement could be demonstrated. Conclusions: In a study cohort with a high proportion of critically ill children suffering from IAH, FVP did not agree reliably with either IVP or IGP. Its clinical use in critically ill children must therefore be strongly discouraged.

Background: In critically ill children, detection of intra-abdominal hypertension (IAH, >10mmHg) and abdominal compartment syndrome (ACS, =IAH + organ dysfunction) is paramount and usually monitored through intra-vesical pressures (IVP) as current standard. IVP however carries important disadvantages, being time-consuming, discontinuous, with infection risk through observer-dependent manipulation, and ill-defined for catheter sizes. Therefore, we sought to validate air-capsule-based measurement of intra-gastric pressure (ACM-IGP).Methods: We prospectively compared ACM-IGP with IVP both in-vivo and in-vitro (water-column), according to Abdominal-Compartment-Society validation criteria. We controlled for patient age, admission diagnosis, gastric filling/propulsive medication, respiratory status, sedation levels and transurethral catheters, all influencing intra-abdominal pressure (IAP).Results: In tertiary care PICU setting, finally, n=97 children were enrolled (median age, 1.3 years [range, 0 days -17 years], LOS-PICU 8.0 [1-332] days, PRISM-III-Score 13 [0-35]). In n=2.770 measurements pairs, median IAP was 6.7 [0.9 -23.0] mmHg. n=38 (39%) children suffered from IAH>10mmHg, n=4 from ACS. In-vitro against water-column, ACM-IGP correlated perfectly (r² 0.99, mean bias -0.1±0.5 mmHg, limits-of-agreement (LOA) -1.1/+0.9, percentage error [PE] 12%) as compared with IVP (r² 0.98, bias +0.7±0.6 mmHg, LOA -0.5/+1.9, PE 15%). With larger IVP catheters at higher pressure levels, IVP underestimated pressures against water-column. In-vivo, agreement between either technique was strong (r² 0.95, bias 0.3±0.8 mmHg, LOA -1.3/+1.9mmHg, PE 23%). No impact of predefined control variables on measurement agreement was observed. Conclusions: In a large PICU population with high IAH prevalence, ACM-IGP agreed favourably with IVP. More wide-spread usage of ACM-IGP may improve detection rates of ACS in critically ill children. Trial registration: WHO-ICTRP-No. DRKS00006556 (German Clinical Trial Register). Registeres 12th September 2014, URL: https://www.drks.de/drks_web/navigate.do?navigationId=trial.HTML&TRIAL_ID=DRKS00006556