Background Intra-abdominal hypertension and abdominal compartment syndrome are common with clinically significant consequences. We investigated the pathophysiological effects of raised IAP as part of ...a more extensive exploratory animal study. The study design included both pneumoperitoneum and mechanical intestinal obstruction models. Methods Forty-nine female swine were divided into six groups: a control group (Cr; n = 5), three pneumoperitoneum groups with IAPs of 20mmHg (Pn20; n = 10), 30mmHg (Pn30; n = 10), 40mmHg (Pn40; n = 10), and two mechanical intestinal occlusion groups with IAPs of 20mmHg (MIO20; n = 9) and 30mmHg (MIO30; n = 5). Results There were significant changes (p<0.05) noted in all organ systems, most notably systolic blood pressure (SBP) (p<0.001), cardiac index (CI) (p = 0.003), stroke volume index (SVI) (p<0.001), mean pulmonary airway pressure (MPP) (p<0.001), compliance (p<0.001), pO2 (p = 0.003), bicarbonate (p = 0.041), hemoglobin (p = 0.012), lipase (p = 0.041), total bilirubin (p = 0.041), gastric pH (p<0.001), calculated glomerular filtration rate (GFR) (p<0.001), and urine output (p<0.001). SVV increased progressively as the IAP increased with no obvious changes in intravascular volume status. There were no significant differences between the models regarding their impact on cardiovascular, respiratory, renal and gastrointestinal systems. However, significant differences were noted between the two models at 30mmHg, with MIO30 showing worse metabolic and hematological parameters, and Pn30 and Pn40 showing a more rapid rise in creatinine. Conclusions This study identified and quantified the impact of intra-abdominal hypertension at different pressures on several organ systems and highlighted the significance of even short-lived elevations. Two models of intra-abdominal pressure were used, with a mechanical obstruction model showing more rapid changes in metabolic and haematological changes. These may represent different underlying cellular and vascular pathophysiological processes, but this remains unclear.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
During pneumoperitoneum, intra-abdominal pressure (IAP) is usually kept at 12-14 mmHg. There is no clinical benefit in IAP increments if they do not increase intra-abdominal volume IAV. We aimed to ...estimate IAV (ΔIAV) and respiratory driving pressure changes (Δ
) in relation to changes in IAP (ΔIAP). We carried out a patient-level meta-analysis of 204 adult patients with available data on IAV and Δ
during pneumoperitoneum from three trials assessing the effect of IAP on postoperative recovery and airway pressure during laparoscopic surgery under general anesthesia. The primary endpoint was ΔIAV, and the secondary endpoint was Δ
. The endpoints' response to ΔIAP was modeled using mixed multivariable Bayesian regression to estimate which mathematical function best fitted it. IAP values on the pressure-volume (PV) curve where the endpoint rate of change according to IAP decreased were identified. Abdomino-thoracic transmission (ATT) rate, that is, the rate Δ
change to ΔIAP was also estimated. The best-fitting function was sigmoid logistic and linear for IAV and Δ
response, respectively. Increments in IAV reached a plateau at 6.0 95%CI 5.9-6.2 L. ΔIAV for each ΔIAP decreased at IAP ranging from 9.8 95%CI 9.7-9.9 to 12.2 12.0-12.3 mmHg. ATT rate was 0.65 95%CI 0.62-0.68. One mmHg of IAP raised Δ
0.88 cmH
O. During pneumoperitoneum, IAP has a nonlinear relationship with IAV and a linear one with Δ
. IAP should be set below the point where IAV gains diminish.
We found that intra-abdominal volume changes related to intra-abdominal pressure increase reached a plateau with diminishing gains in commonly used pneumoperitoneum pressure ranges. We also found a linear relationship between intra-abdominal pressure and respiratory driving pressure, a known marker of postoperative pulmonary complications.
Intra-abdominal hypertension, defined as an intra-abdominal pressure (IAP) equal to or above 12 mmHg is one of the major risk-factors for increased morbidity (organ failure) and mortality in ...critically ill patients. Therefore, IAP monitoring is highly recommended in intensive care unit (ICU) patients to predict development of abdominal compartment syndrome and to provide a better care for patients hospitalized in the ICU. The IAP measurement through the bladder is the actual reference standard advocated by the abdominal compartment society; however, this measurement technique is cumbersome, non-continuous, and carries a potential risk for urinary tract infections and urethral injury. Using microwave reflectometry has been proposed as one of the most promising IAP measurement alternatives. In this study, a novel radar-based method known as transient radar method (TRM) has been used to monitor the IAP in an in vitro model with an advanced abdominal wall phantom. In the second part of the study, further regression analyses have been done to calibrate the TRM system and measure the absolute value of IAP. A correlation of –0.97 with a p-value of 0.0001 was found between the IAP and the reflection response of the abdominal wall phantom. Additionally, a quadratic relation with a bias of −0.06 mmHg was found between IAP obtained from the TRM technique and the IAP values recorded by a pressure gauge. This study showed a promising future for further developing the TRM technique to use it in clinical monitoring.
Metrology part 1: definition of quality criteria Squara, Pierre; Scheeren, Thomas W. L.; Aya, Hollmann D. ...
Journal of clinical monitoring and computing,
02/2021, Letnik:
35, Številka:
1
Journal Article
Recenzirano
Odprti dostop
Any measurement is always afflicted with some degree of uncertainty. A correct understanding of the different types of uncertainty, their naming, and their definition is of crucial importance for an ...appropriate use of measuring instruments. However, in perioperative and intensive care medicine, the metrological requirements for measuring instruments are poorly defined and often used spuriously. The correct use of metrological terms is also of crucial importance in validation studies. The European Union published a new directive on medical devices, mentioning that in the case of devices with a measuring function, the notified body is involved in all aspects relating to the conformity of the device with the metrological requirements. It is therefore the task of the scientific societies to establish the standards in their area of expertise. Adopting the same understandings and definitions among clinicians and scientists is obviously the first step. In this metrologic review (part 1), we list and explain the most important terms defined by the International Bureau of Weights and Measures regarding quantities and units, properties of measurements, devices for measurement, properties of measuring devices, and measurement standards, with specific examples from perioperative and intensive care medicine.
Dear Editor, Recently, Bernon et al. evaluated in a retrospective study the safety and efficacy of prone position (PP) in patients treated for traumatic brain injury (TBI) and moderate-to-severe ...acute respiratory distress syndrome (ARDS) 1. ...the elevated IAP following abdominal compression during PP plays a crucial role during ICP management, particularly in obese patients. U1028, UMR 5292, Lyon Neuroscience Research Center, Bron, France Baptiste Balança Dear Editor, Dabrowski et al. published a letter in the journal about our work reporting data on the safety and efficacy of prone positioning (PP) in patients with acute brain injury and moderate-to-severe acute respiratory distress syndrome (ARDS) 1. ...monitoring IAP could allow optimizing the positioning of patients with a high central venous pressure.
While restrictive fluid regimes have underwent thorough investigation, no large randomized controlled trial (RCT) was able to demonstrate superiority with a restrictive fluid management strategy ...regarding ICU survival. ...it seems it is time to explore the alternative, namely to evaluate de-resuscitation measures, targeted early removal of accumulated fluids, to help us avoid fluid accumulation 4. The primary endpoint, the cumulative fluid balance was significantly lower in the early dry group at intensive care unit (ICU) day 5, death or discharge (median IQR: −7784 −11,833 to −2933 mL) compared to the control group (−3492 −9935 to −1736 mL; p = 0.04). ...the Early Dry study suggests, that perfusion-targeted de-resuscitation with CRRT may be safely used to remove accumulated fluids in critically ill patients with renal failure. In stable patients undergoing intermittent haemodialysis, the TCRR is around 2 to 6 ml/kg per hour but may exceed 10 ml/kg per hour during ultrafiltration 23. ...aiming for a higher net ultrafiltration rate in the EARLY-DRY study would probably have been feasible and resulted in higher net effect with potential impact on the study outcomes.4 Safety limits The investigators of the EARLY-DRY study chose to use a pre-defined norepinephrine equivalent threshold as a safety criterion to start de-resuscitation. The EARLY-DRY study is a well-designed randomized controlled trial in an area of intensive care therapy where there is still much uncertainty with a huge knowledge and research gap.
Hemodynamic instability frequently occurs in critically ill patients. Pathophysiological rationale suggests that hemodynamic monitoring (HM) may identify the presence and causes of hemodynamic ...instability and therefore may allow targeting therapeutic approaches. However, there is a discrepancy between this pathophysiological rationale to use HM and a paucity of formal evidence (as defined by the strict criteria of evidence-based medicine (EBM)) for its use. In this editorial, we discuss that this paucity of formal evidence that HM can improve patient outcome may be explained by both the shortcomings of the EBM methodology in the field of intensive care medicine and the shortcomings of HM itself.
Purpose
Iatrogenic fluid overload is a potential side effect of intravenous fluid therapy in the hospital. Little attention has been paid to sodium administration as a separate cause of harm. With ...this narrative review, we aim to substantiate the hypothesis that a considerable amount of fluid-induced harm is caused not only by fluid volume, but also by the sodium that is administered to hospitalized patients.
Methods
We show how a regular dietary sodium intake is easily surpassed by the substantial amounts of sodium that are administered during typical hospital stays. The most significant sodium burdens are caused by isotonic maintenance fluid therapy and by fluid creep, defined as the large volume unintentionally administered to patients in the form of dissolved medication. In a section on physiology, we elaborate on the limited renal handling of an acute sodium load. We demonstrate how the subsequent retention of water is an energy-demanding, catabolic process and how free water is needed to excrete large burdens of sodium. We quantify the effect size of sodium-induced fluid retention and discuss its potential clinical impact. Finally, we propose preventive measures, discuss the benefits and risks of low-sodium maintenance fluid therapy, and explore options for reducing the amount of sodium caused by fluid creep.
Conclusion
The sodium burdens caused by isotonic maintenance fluids and fluid creep are responsible for an additional and avoidable derailment of fluid balance, with presumed clinical consequences. Moreover, the handling of sodium overload is characterized by increased catabolism. Easy and effective measures for reducing sodium load and fluid retention include choosing a hypotonic rather than isotonic maintenance fluid strategy (or avoiding these fluids when enough free water is provided through other sources) and dissolving as many medications as possible in glucose 5%.
Sepsis is associated with generalised endothelial injury and capillary leak and has traditionally been treated with large volume fluid resuscitation. Some patients with sepsis will accumulate bodily ...fluids. The aim of this study was to systematically review the association between a positive fluid balance/fluid overload and outcomes in critically ill adults, and to determine whether interventions aimed at reducing fluid balance may be linked with improved outcomes.
We searched MEDLINE, PubMed, EMBASE, Web of Science, The Cochrane Database, clinical trials registries, and bibliographies of included articles. Two authors independently reviewed citations and selected studies examining the association between fluid balance and outcomes or where the intervention was any strategy or protocol that attempted to obtain a negative or neutral cumulative fluid balance after the third day of intensive care compared to usual care. The primary outcomes of interest were the incidence of IAH and mortality.
Among all identified citations, one individual patient meta-analysis, 11 randomised controlled clinical trials, seven interventional studies, 24 observational studies, and four case series met the inclusion criteria. Altogether, 19,902 critically ill patients were studied. The cumulative fluid balance after one week of ICU stay was 4.4 L more positive in non-survivors compared to survivors. A restrictive fluid management strategy resulted in a less positive cumulative fluid balance of 5.6 L compared to controls after one week of ICU stay. A restrictive fluid management was associated with a lower mortality compared to patients treated with a more liberal fluid management strategy (24.7% vs 33.2%; OR, 0.42; 95% CI 0.32-0.55; P < 0.0001). Patients with intra-abdominal hypertension (IAH) had a more positive cumulative fluid balance of 3.4 L after one week of ICU stay. Interventions to decrease fluid balance resulted in a decrease in intra-abdominal pressure (IAP): an average total body fluid removal of 4.9 L resulted in a drop in IAP from 19.3 ± 9.1 mm Hg to 11.5 ± 3.9 mm Hg.
A positive cumulative fluid balance is associated with IAH and worse outcomes. Interventions to limit the development of a positive cumulative fluid balance are associated with improved outcomes. In patients not transgressing spontaneously from the Ebb to Flow phases of shock, late conservative fluid management and late goal directed fluid removal (de-resuscitation) should be considered.
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