Search

Microcirculatory alterations play an important role in the early phase of sepsis. Shedding of the endothelial glycocalyx is regarded as a central pathophysiological mechanism causing microvascular dysfunction, contributing to multiple organ failure and death in sepsis. The objective of this study was to investigate whether endothelial glycocalyx thickness at an early stage in septic patients relates to clinical outcome. We measured the perfused boundary region (PBR), which is inversely proportional to glycocalyx thickness, of sublingual microvessels (5-25 µm) using sidestream dark field imaging. The PBR in 21 patients with sepsis was measured within 24 h of admission to the intensive care unit (ICU). In addition, we determined plasma markers of microcirculatory dysfunction and studied their correlation with PBR and mortality. Endothelial glycocalyx thickness in sepsis was significantly lower for non-survivors as compared with survivors, indicated by a higher PBR of 1.97 [1.85, 2.19]µm compared with 1.76 [1.59, 1.97] µm, P=0.03. Admission PBR was associated with hospital mortality with an area under the curve of 0.778 based on the receiver operating characteristic curve. Furthermore, PBR correlated positively with angiopoietin-2 (rho=0.532, P=0.03), indicative of impaired barrier function. PBR did not correlate with Acute Physiology and Chronic Health Evaluation IV (APACHE IV), Sequential Organ Failure Assessment score (SOFA score), lactate, syndecan-1, angiopoietin-1 or heparin-binding protein. An increased PBR within the first 24 h after ICU admission is associated with mortality in sepsis. Further research should be aimed at the pathophysiological importance of glycocalyx shedding in the development of multi-organ failure and at therapies attempting to preserve glycocalyx integrity. [ABSTRACT FROM AUTHOR]

Burn-injured patients provide unique challenges to those providing anaesthesia and pain management. This review aims to update both the regular burn anaesthetist and the anaesthetist only occasionally involved with burn patients in emergency settings. It addresses some aspects of care that are perhaps contentious in terms of airway management, fluid resuscitation, transfusion practices and pharmacology. Recognition of pain management failures and the lack of mechanism-specific analgesics are discussed along with the opioid crisis as it relates to burns and nonpharmacological methods in the management of distressed patients. [ABSTRACT FROM AUTHOR]

To describe the baseline hemodynamic variables and response time of hemodynamic changes associated with the Valsalva maneuver using noninvasive continuous cardiac output monitoring (Nexfin). Hemodynamic monitoring provides an integral component of advanced clinical care and the ability to monitor response to treatment interventions. The emergence of noninvasive hemodynamic monitoring provides clinicians with an opportunity to monitor and assess patients rapidly with ease of implementation. However, the responsiveness of this method in tracking dynamic changes that occur has not been fully elucidated. A prospective observational study was conducted involving 44 healthy volunteers (age = 38 ±12 years). Participants performed a Valsalva maneuvers to illicit dynamic changes in blood pressure, cardiac output, cardiac index, systemic vascular resistance index (SVRI), and stroke volume. Changes in these hemodynamic parameters were monitored while performing repeated standardized Valsalva maneuvers. Baseline hemodynamic values were obtained in all 44 participants, and showed an interaction with age, accompanying a significant decline in cardiac index (r = –.66, p <.05) and stroke volume (r = –.68, p <.05), and an increase in SVRI (r =.67, p <.05) with increasing age. The Valsalva maneuver, performed in 20 participants, resulted in a change of 10% from baseline blood pressure and cardiac index, which was detected within 4.53 s (SD = 4.36) and 3.31 s (SD = 2.21), respectively. Noninvasive continuous cardiac monitoring demonstrated the ability to rapidly detect logical and predictable hemodynamic changes. These observations suggest that such Nexfin technology may have useful clinical applications. [ABSTRACT FROM AUTHOR]

Transpulmonary thermodilution devices have been widely shown to be accurate in septic shock patients in assessing fluid responsiveness. We conducted a systematic review to assess the relationship between fluid therapy protocols guided by transpulmonary thermodilution devices on fluid balance and the amount of intravenous fluid used in septic shock. We searched MEDLINE, Embase and The Cochrane Library. Studies were eligible for inclusion if they were prospective, parallel trials that were conducted in an intensive care setting in patients with septic shock. The comparator group was either central venous pressure, early goal-directed therapy or pulmonary artery occlusion pressure. Studies assessing only the accuracy of fluid responsiveness prediction by transpulmonary thermodilution devices were excluded. Two reviewers independently performed the search, extracted data and assessed the bias of each study. In total 27 full-text articles were identified for eligibility; of these, nine studies were identified for inclusion in the systematic review. Three of these trials used dynamic parameters derived from transpulmonary thermodilution devices and six used primarily static parameters to guide fluid therapy. There was evidence for a significant reduction in positive fluid balance in four out of the nine studies. From the available studies, the results suggest the benefit of transpulmonary thermodilution monitoring in the septic shock population with regard to reducing positive fluid balance is seen when the devices are utilised for at least 72 hours. Both dynamic and static parameters derived from transpulmonary thermodilution devices appear to lead to a reduction in positive fluid balance in septic shock patients compared to measurements of central venous pressure and early goal-directed therapy. [ABSTRACT FROM AUTHOR]

An audit of ten years' experience in all patients undergoing withdrawal of cardiorespiratory support (WCRS) in the context of donation after circulatory death (DCD) was conducted in Queensland, Australia (2008 to 2017). One hundred and seventy-one patients proceeded to donation after declaration of death by circulatory criteria with loss of pulsatile arterial blood pressure (circulatory arrest) for five minutes. The demographics, times and haemodynamic observations were abstracted, de-identified and collated. The average age of patients was 43 years (standard deviation 16.1 years) and 63% were male. The median and mean times to an agonal systolic blood pressure below 50 mmHg were 10 and 11 minutes and the median and mean times from WCRS to circulatory arrest were 14 and 16 minutes. After systolic blood pressure fell to 50 mmHg or lower, 33 patients (19.3%) had spontaneous return of systolic pressure to above 50 mmHg. Following periods of circulatory arrest, five patients were documented to have spontaneous return of pulsatile arterial pressure. Two patients had return of circulation after two minutes, but less than five minutes of circulatory arrest and three patients had return of circulation where circulatory arrest had been documented for less than two minutes. Following WCRS, transient restoration of circulation following circulatory arrest may occur, even following two minutes of circulatory asystole, albeit rarely. [ABSTRACT FROM AUTHOR]

The primary objective was to non-invasively measure the cardiac index (CI) and associated haemodynamic parameters of healthy volunteers and their changes with age. This was a single centre, prospective, observational study of healthy volunteers aged between 20 and 59 years, using the ClearSight™ (Edwards Life Sciences, Irvine, CA, USA) device. We recorded 514 observations in 97 participants. The mean CI was 3.5 l/min/m2 (95% confidence interval [95% CI] 3.4 to 3.7 l/min/m2). The mean stroke volume index (SVI) was 47 ml/m2 (95% CI 45 to 49 ml/m2) and the mean systemic vascular resistance index was 2,242 dyne.s/cm5/m2 (95% CI 2,124 to 2,365 dyne.s/cm5/m2). There was an inverse linear relationship between increasing age and CI (P <0.0001), which decreased by 0.044 l/min/m2 (95% CI  -0.032 to -0.056 l/min/m2) per year. This change was mostly due to a decrease in SVI of 0.45 ml/m2 (95% CI 0.32 to 0.57 ml/m2) per year (P <0.0001). The mean CI of young healthy humans is approximately 3.5 l/min/m2 and declines by approximately 40 ml/min/m2 per year, mostly due to a decline in stroke volume (SV). These findings have significant implications regarding the clinical interpretation of haemodynamic parameters and the application of these results to individual patients. [ABSTRACT FROM AUTHOR]

Monitoring of cardiac index (CI) by uncalibrated pulse contour (PC) methods has been shown to be inaccurate in critically ill patients. We tested accuracy and trending of a new pulse contour method and a modified Fick method using central venous oxygen saturation. We studied 21 critically ill and mechanically ventilated patients (age 20-86 years) monitored by PC (PulsioFlex®) and transpulmonary thermodilution (TPTD, PiCCO2®) as reference. At baseline, reference and PC-derived CI (CIPC) were recorded and CI obtained by Fick's method (FM, CIFICK). After four hours, measurements were performed analogously for trending analysis. CI are given in l/min/m2 as mean±standard deviation. At baseline CITPTD was 3.7±0.7, CIPC 3.8±0.7 and CIFICK 5.2±1.8. After 4 hours, CITPTD was 3.5±0.6, CIPC 3.8±1.2 and CIFICK 4.8±1.7. Mean bias for PC at baseline was -0.1 (limits of agreement [LOA] -1.4 to 1.2) and -0.4 (LOA -2.6 to 1.9) after four hours. Percentage errors (PE) were 34% and 60% respectively. FM revealed a bias of -1.5 (LOA -4.8 to 1.8, PE 74%) at baseline and -1.5 (LOA -4.5 to 1.4, PE 68%) at four hours. With an exclusion window of 10% of mean cardiac index, trending analysis by polar plots showed an angular bias of 5° (radial LOA±57°) for PC and 16° (radial LOA±51°) for FM. Although PC values at baseline were marginally acceptable, both methods fail to yield clinically acceptable absolute values. Likewise, trending ability is not adequate for both methods to be used in critically ill patients. [ABSTRACT FROM AUTHOR]

The T-Line(®) system (Tensys(®) Medical Inc., San Diego, CA, USA) non-invasively estimates cardiac output (CO) using autocalibrating pulse contour analysis of the radial artery applanation tonometry-derived arterial waveform. We compared T-Line CO measurements (TL-CO) with invasively obtained CO measurements using transpulmonary thermodilution (TDCO) and calibrated pulse contour analysis (PC-CO) in patients after major gastrointestinal surgery. We compared 1) TL-CO versus TD-CO and 2) TL-CO versus PC-CO in 27 patients treated in the intensive care unit (ICU) after major gastrointestinal surgery. For the assessment of TD-CO and PC-CO we used the PiCCO(®) system (Pulsion Medical Systems SE, Feldkirchen, Germany). Per patient, we compared two sets of TD-CO and 30 minutes of PC-CO measurements with the simultaneously recorded TL-CO values using Bland-Altman analysis. The mean of differences (± standard deviation; 95% limits of agreement) between TL-CO and TD-CO was -0.8 (±1.6; -4.0 to +2.3) l/minute with a percentage error of 45%. For TL-CO versus PC-CO, we observed a mean of differences of -0.4 (±1.5; -3.4 to +2.5) l/minute with a percentage error of 43%. In ICU patients after major gastrointestinal surgery, continuous non-invasive CO measurement based on autocalibrating pulse contour analysis of the radial artery applanation tonometry-derived arterial waveform (TL-CO) is feasible in a clinical study setting. However, the agreement of TL-CO with TD-CO and PC-CO observed in our study indicates that further improvements are needed before the technology can be recommended for clinical use in these patients. [ABSTRACT FROM AUTHOR]

Optimising intravascular volume in patients with hypotension requiring vasopressor support is a key challenge of critical care medicine. The optimal haemodynamic parameter to assess fluid responsiveness in critically ill patients, particularly those requiring a noradrenaline infusion and mechanical ventilation, remains uncertain. This pilot study assessed the accuracy of the plethysmographic variability index (PVI), (Radical-7 pulse co-oximeter, Masimo®, Irvine, CA, USA) in predicting fluid responsiveness in 25 patients who required noradrenaline infusion to maintain mean arterial pressure over 65 mmHg and were mechanically ventilated with a 'lung-protective' strategy, and whether administering a fluid bolus was associated with a change in PVI (ΔPVI). In this study, fluid responsiveness was defined as an increase in stroke volume of greater than 15% after a 500 ml bolus of colloid infusion over 20 minutes. Of the 25 patients included in the study, only 12 (48%) were considered fluid responders. As static haemodynamic parameters, PVI, central venous pressure and inferior vena cava distensibility index were all inaccurate at predicting volume responsiveness with PVI being the least accurate (area under the receiver operating characteristic curve=0.41, 95% confidence interval 0.18 to 0.65). However, fluid responsiveness was associated with a change in PVI, but not a change in heart rate or central venous pressure. This association between ΔPVI and fluid responsiveness may be a surrogate marker of improved cardiac output following a fluid bolus and warrants further investigation. [ABSTRACT FROM AUTHOR]

The article discusses the incidence of pulmonary oedema in pre-eclamptic women after intravenous fluid administration. Topics explored include pulmonary capillary wedge pressure changes which may be attributed to fluid therapy, the proper monitoring of intravenous fluid administration in these women, and other factors which may contribute to pulmonary oedema such as diastolic dysfunction, severe hypertension and reduced oncotic pressure.

The article presents a study which examined the continuous central venous oxygen saturation during different physical conditions in an animal model. An overview of the methodology used for the study is provided, including experimental protocols, drug infusions and ventilation with hypoxic gas. Among the factors affecting the ability of the catheter to effectively monitor the saturation of blood flow through the vessels include the emission of infrared light and infrared light.

The article discusses the effectiveness of the devices used to evaluate cardiac output (CO) in critically ill patients. It compares the CO between the Swan Ganz catheter and the Flotrac/Vigileo monitors. In the study, the arterial pressure cardiac output (APCO), continuous cardiac output (CCO) and instantaneous cardiac output (ICO) were measured. Results showed that there is a big inter-individual variability between the two devices.

■ The use of arterial line monitoring in critically ill children provides an indispensable foundation of critical care. [ABSTRACT FROM PUBLISHER]