Infusion System Architecture Impacts the Ability of Intensive Care Nurses to Maintain Hemodynamic Stability in a Living Swine Simulator

2016 ◽  
Vol 124 (5) ◽  
pp. 1077-1085 ◽  
Author(s):  
Matthew J. Pezone ◽  
Robert A. Peterfreund ◽  
Mikhail Y. Maslov ◽  
Radhika R. Govindaswamy ◽  
Mark A. Lovich
Keyword(s):  
Blood Pressure ◽  
Intensive Care ◽  
Vena Cava ◽  
Hemodynamic Instability ◽  
Drug Infusion ◽  
Hemodynamic Stability ◽  
Time Integral ◽  
Arterial Blood ◽  
Infusion Systems ◽  
Infusion System

Abstract Background The authors have previously shown that drug infusion systems with large common volumes exhibit long delays in reaching steady-state drug delivery and pharmacodynamic effects compared with smaller common-volume systems. The authors hypothesized that such delays can impede the pharmacologic restoration of hemodynamic stability. Methods The authors created a living swine simulator of hemodynamic instability in which occlusion balloons in the aorta and inferior vena cava (IVC) were used to manipulate blood pressure. Experienced intensive care unit nurses blinded to the use of small or large common-volume infusion systems were instructed to maintain mean arterial blood pressure between 70 and 90 mmHg using only sodium nitroprusside and norepinephrine infusions. Four conditions (IVC or aortic occlusions and small or large common volume) were tested 12 times in eight animals. Results After aortic occlusion, the time to restore mean arterial pressure to range (t1: 2.4 ± 1.4 vs. 5.0 ± 2.3 min, P = 0.003, average ± SD), time-out-of-range (tOR: 6.2 ± 3.5 vs. 9.5 ± 3.4 min, P = 0.028), and area-out-of-range (pressure–time integral: 84 ± 47 vs. 170 ± 100 mmHg·min, P = 0.018) were all lower with smaller common volumes. After IVC occlusion, t1 (3.7 ± 2.2 vs. 7.1 ± 2.6 min, P = 0.002), tOR (6.3 ± 3.5 vs. 11 ± 3.0 min, P = 0.007), and area-out-of-range (110 ± 93 vs. 270 ± 140 mmHg·min, P = 0.003) were all lower with smaller common volumes. Common-volume size did not impact the total amount infused of either drug. Conclusions Nurses did not respond as effectively to hemodynamic instability when drugs flowed through large common-volume infusion systems. These findings suggest that drug infusion system common volume may have clinical impact, should be minimized to the greatest extent possible, and warrants clinical investigations.

scholarly journals Drug Flow Through Clinical Infusion Systems: How Modeling of the Common-volume Helps Explain Clinical Events

2017 ◽  
Vol 2 (2) ◽  
Author(s):  
Mark A. Lovich ◽  
Robert A. Peterfreund
Keyword(s):  
Drug Delivery ◽  
Computational Simulation ◽  
Hemodynamic Instability ◽  
Infusion Therapy ◽  
Drug Infusion ◽  
Infusion Systems ◽  
The Common ◽  
The Impact ◽  
Infusion System

AbstractThis review aims to describe analytic models of drug infusion that demonstrate the impact of the infusion system common-volume on drug delivery. The common-volume of a drug infusion system is defined as the volume residing between the point where drug and inert carrier streams meet and the patient’s blood. We describe 3 sets of models. The first is quantitative modeling which includes algebraic mathematical constructs and forward-difference computational simulation. The second set of models is with in vitro benchtop simulation of clinical infusion system architecture. This modeling employs devices including pumps, manifolds, tubing and catheters used in patient care. The final set of models confirms in vitro findings with pharmacodynamic endpoints in living large mammals. Such modeling reveals subtle but important issues inherent in drug infusion therapy that can potentially lead to patient instability and morbidity. The common-volume is an often overlooked reservoir of drugs, especially when infusions flows are slowed or stopped. Even with medications and carriers flowing, some mass of drug always resides within this common-volume. This reservoir of drug can be inadvertently delivered into patients. When infusions are initiated, or when dose rate or carrier flow is altered, there can be a significant lag between intended and actual drug delivery. In the case of vasoactive and inotropic drug infusions, these unappreciated time delays between intended and actual drug delivery can lead to iatrogenic hemodynamic instability. When a drug infusion is discontinued, drug delivery continues until the common-volume is fully cleared of residual drug by the carrier. The findings from all 3 sets of models described in this review indicate that minimizing the common-volume of drug infusion systems may enhance patient safety. The presented models may also be configured into teaching tools and possibly point to technological solutions that might mitigate sources of iatrogenic patient lability.

scholarly journals The Association Between Arterial Oxygen Level and Outcome in Neurocritically Ill Patients is not Affected by Blood Pressure

2021 ◽  
Author(s):  
Jaana Humaloja ◽  
Markus B. Skrifvars ◽  
Rahul Raj ◽  
Erika Wilkman ◽  
Pirkka T. Pekkarinen ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Intensive Care ◽  
Brain Injury ◽  
Hemodynamic Instability ◽  
Arterial Oxygen ◽  
Admission Diagnosis ◽  
Secondary Brain Injury ◽  
Multivariable Logistic Regression Model ◽  
Mechanically Ventilated ◽  
The Relationship

Abstract Background In neurocritically ill patients, one early mechanism behind secondary brain injury is low systemic blood pressure resulting in inadequate cerebral perfusion and consequent hypoxia. Intuitively, higher partial pressures of arterial oxygen (PaO2) could be protective in case of inadequate cerebral circulation related to hemodynamic instability. Study purpose We examined whether the association between PaO2 and mortality is different in patients with low compared to normal and high mean arterial pressure (MAP) in patients after various types of brain injury. Methods We screened the Finnish Intensive Care Consortium database for mechanically ventilated adult (≥ 18) brain injury patients treated in several tertiary intensive care units (ICUs) between 2003 and 2013. Admission diagnoses included traumatic brain injury, cardiac arrest, subarachnoid and intracranial hemorrhage, and acute ischemic stroke. The primary exposures of interest were PaO2 (recorded in connection with the lowest measured PaO2/fraction of inspired oxygen ratio) and the lowest MAP, recorded during the first 24 h in the ICU. PaO2 was grouped as follows: hypoxemia (< 8.2 kPa, the lowest 10th percentile), normoxemia (8.2–18.3 kPa), and hyperoxemia (> 18.3 kPa, the highest 10th percentile), and MAP was divided into equally sized tertiles (< 60, 60–68, and > 68 mmHg). The primary outcome was 1-year mortality. We tested the association between hyperoxemia, MAP, and mortality with a multivariable logistic regression model, including the PaO2, MAP, and interaction of PaO2*MAP, adjusting for age, admission diagnosis, premorbid physical performance, vasoactive use, intracranial pressure monitoring use, and disease severity. The relationship between predicted 1-year mortality and PaO2 was visualized with locally weighted scatterplot smoothing curves (Loess) for different MAP levels. Results From a total of 8290 patients, 3912 (47%) were dead at 1 year. PaO2 was not an independent predictor of mortality: the odds ratio (OR) for hyperoxemia was 1.16 (95% CI 0.85–1.59) and for hypoxemia 1.24 (95% CI 0.96–1.61) compared to normoxemia. Higher MAP predicted lower mortality: OR for MAP 60–68 mmHg was 0.73 (95% CI 0.64–0.84) and for MAP > 68 mmHg 0.80 (95% CI 0.69–0.92) compared to MAP < 60 mmHg. The interaction term PaO2*MAP was nonsignificant. In Loess visualization, the relationship between PaO2 and predicted mortality appeared similar in all MAP tertiles. Conclusions During the first 24 h of ICU treatment in mechanically ventilated brain injured patients, the association between PaO2 and mortality was not different in patients with low compared to normal MAP.

Oncologic Emergencies

2011 ◽  
Vol 22 (4) ◽  
pp. 337-348 ◽  
Author(s):  
Regan Demshar ◽  
Rachel Vanek ◽  
Polly Mazanec
Keyword(s):  
Intensive Care Unit ◽  
Intensive Care ◽  
Superior Vena ◽  
Tumor Lysis Syndrome ◽  
Vena Cava ◽  
Hemodynamic Instability ◽  
Cord Compression ◽  
Current Evidence ◽  
Oncologic Emergencies ◽  
Life Threatening

The picture of oncologic emergencies in the intensive care unit has changed over the past decade. The classic emergencies, that is, superior vena cava syndrome, spinal cord compression, tumor lysis syndrome and life-threatening hypercalcemia, are now routinely managed on the general oncology unit or in an outpatient setting. Vigilant monitoring for early signs of complications, proactive interventions to prevent complications, and aggressive management account for this change. Currently, emergent conditions that necessitate intensive care unit admission or transfer in the patient with cancer include respiratory failure, cardiac emergencies, hemorrhagic events and coagulopathies, sepsis, and hemodynamic instability. This article will present the current evidence-based management of these conditions, a brief summary of classic oncologic emergencies, and the role of the critical care nurse in meeting the multidimensional needs of the patient and family during the life-threatening episode, based on Ferrell’s quality of life model.

scholarly journals Dexmedetomidine and magnesium sulphate as the anaesthetic adjuncts for intraoperative management for resection of pheochromocytoma - a case report

2016 ◽  
Vol 3 (2) ◽  
pp. 87-89
Author(s):  
Gentle Sunder Shrestha ◽  
Sachit Sharma Rupakhetee ◽  
Sunil Pathak ◽  
Pragya Acharya ◽  
Bashu Dev Parajuli ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Magnesium Sulphate ◽  
Antihypertensive Agents ◽  
Hemodynamic Instability ◽  
Tumour Resection ◽  
Tumour Site ◽  
Hemodynamic Stability ◽  
Intraoperative Management ◽  
History Of ◽  
Acute Changes

Pheochromocytoma, a tumour arising from adrenal medulla or other ganglia of sympathetic nervous system is notorious for secreting catecholamines. This form of the tumour is a major challenge to anaesthesia team as acute changes in blood pressure and heart rate usually occurs due to the release of catecholamines from the tumour site before tumour resection and cessation of the same after resection leading to hemodynamic instability intraoperatively. Better hemodynamic stability is desired during this form of tumour resection as acute fluctuations in blood pressure may lead to severe intracranial or cardiovascular events. Dexmedetomidine and magnesium sulphate were used as anaesthetic adjuncts to achieve good hemodynamic stability in a 35 years old female who presented with the history of headaches, palpitation and sweating on and off since last 2 years. The use of these agents allowed us to obtain an acceptable level of hemodynamic stability along with the help of other agents such as inotropes, vasopressors, vasodilators and antihypertensive agents. Dexmedetomidine and magnesium sulphate were used before resection of the tumour in our case and stopped thereafter. These agents may be an excellent option as anaesthetic adjuncts to obtain greater hemodynamic stability during resection of pheochromocytoma.

An intracaval cannulation for obtaining pure, mixed hepatic venous blood samples

1978 ◽  
Vol 235 (2) ◽  
pp. H262-H265
Author(s):  
W. W. Lautt ◽  
C. Wong ◽  
J. S. Durham ◽  
P. Taillon
Keyword(s):  
Blood Pressure ◽  
Venous Blood ◽  
Vena Cava ◽  
Direct Stimulation ◽  
Blood Samples ◽  
Arterial Blood ◽  
Vascular Congestion ◽  
Hepatic Venous Blood ◽  
Surgical Preparation ◽  
Hepatic Nerves

A method for obtaining pure, mixed hepatic venous blood is described and evaluated in anesthetized cats. Hepatic vascular congestion does not occur with this “intracaval cannulation”, however small elevations in central venous blood pressure were noted. Although these changes persisted they did not result in systemic vascular congestion, judging from the normal arterial and portal pressures and from the lack of progressive decrease in arterial blood pressure. Blood samples obtained using the intracaval cannulation were shown to contain identical levels of oxygen as those obtained using a more complex surgical preparation. Reflux of blood from the vena cava does not occur during sampling. The responsiveness of this sampling method to rapid changes in venous content was evaluated by following the changes in glucose balance caused by direct stimulation of the hepatic nerves. The responses measured were similar to those measured in a separate set of experiments obtained using blood samples from a surgically isolated hepatic venous supply.

P3531Continual measurement of arterial dP/dtmax enables mini-invasive monitoring of left ventricular contractility in acute heart failure

2019 ◽  
Vol 40 (Supplement_1) ◽  
Author(s):  
D Vondrakova ◽  
D V Vondrakova ◽  
A K Kruger ◽  
M J Janotka ◽  
P N Neuzil ◽  
...  
Keyword(s):  
Heart Failure ◽  
Blood Pressure ◽  
Intensive Care ◽  
Acute Heart Failure ◽  
Hemodynamic Monitoring ◽  
Continuous Wave ◽  
Left Ventricular ◽  
Waveform Analysis ◽  
Arterial Line ◽  
Arterial Blood

Abstract Introduction Continuous reliable evaluating of left ventricular (LV) contractile function in patients with advanced heart failure requiring intensive care remains challenging. Recently, continual monitoring of dP/dtmax from arterial line became available for hemodynamic monitoring. However, the relation between arterial dP/dtmax and LV dP/dtmax measurement is not fully understood. Purpose The aim of our study was to determine the relation of arterial dP/dtmax and LV dP/dtmax assessed by echocardiography in patients with acute heart failure. Methods Forty-eight patients with acute heart failure requiring intensive care and hemodynamic monitoring were recruited into the study (mean age 70.4 years, 65% were males). Hemodynamic variables including arterial dP/dtmax were continually monitored using arterial line pressure waveform analysis. LV dP/dtmax was assessed using continuous-wave Doppler analysis of mitral regurgitation flow. Results The values from continual arterial dP/dtmax monitoring significantly correlated with the LV dP/dtmax assessed by echocardiography (r=0.72, 95% confidence interval [CI] 0.54–0.83, P<0.0001). Linear regression revealed that (LV dP/dtmax) = 0.87×(arterial dP/dtmax) + 291, P<0.0001. Arterial dP/dtmax significantly correlated also with the stroke volume (r=0.55, P<0.0001), cardiac output (r=0.32, P=0.0289), mean arterial blood pressure (r=0.43, P=0.0155) and systolic blood pressure (r=0.79, P<0001). On the other hand arterial dP/dtmax did not correlate with the systemic vascular resistance (SVR), heart rate, dynamic arterial elastance, diastolic blood pressure or central venous pressure. Conclusion Our results revealed that arterial dP/dtmax values tightly and highly significantly correlate with LV dP/dtmax. Arterial dP/dtmax could be, therefore, used for continual monitoring of LV contractility. Acknowledgement/Funding Institutional grant MH CZ - DRO (Na Homolce Hospital- NNH, 00023884), IG150501

scholarly journals Intramucosal pH as a criterion for the organism emergency from hepatospanchnic ischemia, or centralization of blood flow

2021 ◽  
Vol 17 (3) ◽  
pp. 10-14
Author(s):  
L.O. Maltseva ◽  
V.M. Lisnycha ◽  
I.A. Malsev ◽  
N.A. Kazimirova
Keyword(s):  
Blood Pressure ◽  
Intensive Care ◽  
Intensive Therapy ◽  
Tissue Perfusion ◽  
Regional Perfusion ◽  
Critical Conditions ◽  
Intramucosal Ph ◽  
Arterial Blood ◽  
The Difference ◽  
Splanchnic Hypoperfusion

In critical conditions, despite the restoration of systemic hemodynamics and overall oxygen delivery, tissue hypoxia and reduced oxygen extraction remain. One of the important tasks of intensive care for critical conditions is the early diagnosis of tissue perfusion disorders. In clinical circumstances, signs of hypoperfusion are arterial hypotension, tachycardia, oliguria, encephalopathy, low body temperature, the disappearance of skin capillary pattern, metabolic lactate acidosis. However, blood pressure is an insensitive indicator of tissue hypoperfusion itself. Experimental clinical trials have repeatedly documented that local perfusion pressure in critical conditions does not directly depend on systemic blood pressure. Lactate is not a specific marker of anaerobic metabolism, but rather impaired microcirculation seems to be one of the possible mechanisms of hyperlactatemia. Reliable markers of tissue perfusion and the effectiveness of early targeted therapy are regional capnometry (gastric intramucosal pH, sublingual pCO2), a saturation of mixed venous blood, etc. Intramucosal pH is of particular practical importance as a marker of regional capnometry. The aim of the study is the analysis of literature sources devoted to the effectiveness and diagnostic significance of intramucosal pH as a marker of regional perfusion. The value of intramucosal pH was evaluated: 1) during abdominal operations and the development of postoperative complications in comparison against IL-6 and IL-8; 2) during and after surgical interventions in conditions of prolonged cardiopulmonary bypass to assess the adequacy of blood supply to the abdominal organs; 3) in experimental septic shock compared to the values of lactate and hypoxanthine concentration in the liver and arterial blood; 4) the correlation between intramucosal pH va-lues, indices of the pediatric mortality risk scale, forming of great (cardiac arrest, shock) and minor (hypotension, hypovolemia, arrhythmia) hemodynamic complications and duration of staying in intensive care unit and intensive therapy; 5) during laparoscopic cholecystectomy in apparently healthy patients with the simultaneous calculation of the difference between arterial and intramucosal pH. Intramuscular pH-controlled intensive therapy is a separate fragment: an intramucosal pH of less than 7.3 reflects splanchnic hypoperfusion and is an indicator of the unfavorable outcomes; intramucousal pH of more than 7.3 is a criterion for the emergency of the organism from hepatosplanchic ischemia, i.e. centralization of blood circulation. Therefore, the intramucosal pH is valuable in the clinical picture of critical conditions as a marker of regional perfusion measured by capnometry, which allows monitoring that reflects the perfusion of the intestinal wall. The lower threshold is 7.35 (the sensitivity of the method is 67 %, specificity is 74 %). An intramucosal pH of < 7.3 reflects splanchnic hypoperfusion and is an indicator of an adverse outcome. An alternative measurement of intramucosal pCO2, pCO2 in arterial blood and the difference [P (1-a) CO2] is a more reliable index of intestinal oxygenation than single intramucosal pH, but rather pH (1-a) makes it possible to adequately assess the acid-base state of arterial blood. The improvement and widespread use of capnometry and capnography for monitoring during general anaesthesia and intensive care, on the one hand, and modern knowledge of the pathophysiology of gas exchange, on the other hand, stimulate the wider use of less invasive and more affordable methods of regional capnometry and aerial tonometry.

997 Nadir Mean Arterial Blood Pressure During the First Day of Admission to the Intensive Care Unit (ICU) Is Associated With ICU Mortality

2019 ◽  
Vol 114 (1) ◽  
pp. S578-S579
Author(s):  
Jennifer L. Peng ◽  
Sarah M. Russell ◽  
Hani Shamseddeen ◽  
Carla D. Kettler ◽  
Caitriona A. Buckley ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Intensive Care Unit ◽  
Intensive Care ◽  
Arterial Blood Pressure ◽  
Mean Arterial Blood Pressure ◽  
Icu Mortality ◽  
Arterial Blood
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