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http://www.webmedcentral.com/images/Header_Logo.giftext/html2010-09-29T08:05:13+01:00http://www.webmedcentral.com/Dr. David SturgessNon-Invasive Rodent Cardiac Output: Comparison of a Compact Clinical Monitor with Echocardiography
http://www.webmedcentral.com/article_view/759
Background: There are limited options for non-invasive cardiac output (CO) measurement in rodents. This study aimed to compare a commercially available human CO monitor, USCOM® (USCOM Ltd, Sydney, Australia), with specialised rodent echocardiography for rat CO measurement.Methods: With institutional ethics committee approval, twenty-one anaesthetised, mechanically-ventilated male Sprague-Dawley rats (573±96g) were studied during refinement and study of an endotoxic shock model. Pulsed-wave Doppler echocardiography (15MHz rodent probe) was used to measure left ventricular (LV) outflow velocity and calculate stroke volume and CO. USCOM (v1.7; 2.2MHz) CO measurements followed each echocardiographic examination. USCOM CO was measured by combining continuous wave Doppler with predicted outflow tract diameter (OTD-U).Results: 21 paired measurements were analysed. Mean echocardiographic CO was 113mL/min (range 46–236). Mean USCOM CO was 245mL/min (range 75-553). Paired echocardiographic and USCOM measurements demonstrated significant correlations for heart rate (r=0.92, P≤0.0001) and CO (r=0.68, P=0.001). Bland Altman analysis of CO demonstrated mean bias of -131mL/min and precision of 52mL/min. Linear regression analysis yielded a simple correction factor for USCOM OTD estimation. Following application of this correction factor (0.68*OTD-U), mean bias improved to -0.1mL/min with precision of 38mL/min.Conclusions: USCOM (v1.7) is not interchangeable with pulsed-wave Doppler echocardiography for measuring rat CO. We propose a simple correction factor that should improve performance of this device in the rodent laboratory. Incorporation into a rat-specific algorithm should be evaluated prospectively across a range of potential applications.text/html2011-02-25T22:17:02+01:00http://www.webmedcentral.com/Dr. Gian Domenico GiustiCorrect Placement Nasogastric Tube In Intensive Care Unit. A Brief Case Report
http://www.webmedcentral.com/article_view/1606
Nasogastric intubation is the placement of a marked tube into the stomach through the nose or mouth.
This is an usually Intensive Care Unit (ICU) personnel procedure with the following purposes:
-to drainage and analyse stomach’s contents
-continuous drainage
-to decompress the gastrointestinal tract
-to administer drugs and other oral agents
-for diagnostic reasons
-for continuous feeding [1]
To ensure proper placement performing the whoosh test is recommended (though not unequivocally confirmed). The “whoosh test” is the air injection trough the tube, if the air is heard in the stomach with a stethoscope, we assume the tube is in the correct position. Gurgling is heard when air enters the stomach, whilst its absence suggests the tip of the NGT is elsewhere (lung, esophagus, pharynx, and so on) [2].text/html2011-06-10T20:01:59+01:00http://www.webmedcentral.com/Dr. Deepak GuptaIntravenous Immunonutrition: It is Time for Endodermal Protection (Gut and Lung Prophylaxis)
http://www.webmedcentral.com/article_view/1972
There is a constant debate [1-3] related to the utility of immunonutrition (enteral and parenteral) and the abundance of data to endorse or refute the claims of the immunonutrition. The authors want to present an alternative perspective. Firstly, the term ‘immunonutrition’ is misread because the clinicians stress its nutritive value over its contribution to immunity; this can be easily undone with rephrasing the term as ‘immunoprophylaxis’ to initiate its consideration in the lines of stress ulcer prophylaxis and deep vein thrombosis prophylaxis. Secondly, the medical community is concerned whether a critically ill patient needs this form of prophylaxis. Stress ulcers and deep vein thrombosis pose immediate threat to the life of the bedridden patients under the stress of critical illness. However, the endodermal structures (gastrointestinal villi and pulmonary alveoli) weakened by the endogenous insults (critical illness, infection, hemodynamic instability, paralytic ileus and catabolism) and the exogenous insults (mechanical ventilation, operative trauma, operator’s handling and starvation) need blanket strengthening in the form of ‘immunonutrition’ till the patient’s bodily functions transition to convalescent phase. Thirdly, the blanket parenteral immunoprophylaxis (BPIP) with seven-day-intravenous-glutamine-protocol (similar to as used by Gatt and MacFie [4] in one of their research study) for endodermal protection will clear the cloud of uncertainty over the route and timing of ‘immunonutrition’. Except for the patients who are expected to tolerate enteral nutrition at goals in the first 24-48 hrs of their admissions to intensive care units, every critically ill patient will meet the criteria for BPIP because the severity of the ongoing patho-physiological insults to the endodermal structures cannot be predictably quantified and avoided. BPIP will ensure the vascular delivery of the immunonutrients at the endodermal sites as against the unpredictable peristaltic activity-based delivery of the enteral immunonutrients especially in the first week or so after the major operative trauma. This will buy more time for the patient’s body to recover from the primary critical illness and to resist the autolytic actions of the inflammatory mediators released by the weak-endodermal tissues. Without BPIP, there is the certainty of unanticipated deterioration in some otherwise stable patients in whom the window for effective immunoprophylaxis is lost. Fourthly, it cannot be quantified with certainty whether BPIP will do more harm than good of delaying bacterial translocation, sepsis, and acute lung injury/acute respiratory distress syndrome. However, the evidence endorsing or refuting BPIP can always be collected as part of Phase III/IV trial without any further delay in the advantages incurred for the critically ill patient population. Finally, the costs for BPIP (intravenous glutamine @ 700 USD per week) will only need three-to-four and half patients to treat to save a 2000-3000 USD per day stay in intensive care unit. The authors are confident that the Phase IV evidence of the costs saved (in terms of morbidity-mortality) by BPIP will be much more than abovementioned numbers or the costs saved by stress ulcer prophylaxis [5]. In summary, it is time [6] and we as the community of intensivists should endorse the virtual Phase III/IV trial of BPIP to protect the endodermal structures from getting harmed and in turn harming the body.text/html2011-08-26T18:34:38+01:00http://www.webmedcentral.com/Dr. Christine N GraceMyocardial Ischemia and Central-mixed Venous Oxygen Saturation Gradient.
http://www.webmedcentral.com/article_view/2113
Objective
Detection of Myocardial ischemia in post coronary artery bypass grafting patients.DesignProspectively simultaneous central venous Oxygen (ScvO2) & mixed venous oxygen (SVO2) saturation on hourly interval will be analysed from patients coming to ICU after coronary artery bypass surgery.SettingCardiac surgery Intensive Care unit, King Abdul Aziz University Hospital Jeddah. Saudi Arabia.PatientsAll post CABG patients with a Pulmonary artery catheter (PAC) were included in study.Main results30 patients were enrolled in the study; simultaneous ScvO2 & SVO2 on hourly basis for the first 6 hours were done in post CABG patients via a PAC. 6/ 30 patients had a peak troponin > 40 ng/ml (1) while 24/30 had a troponin surge < 40 ng/ml. Patient with high Troponin surge ( > 40 ng/ml) were generally older, higher incidence of on going smoking, diabetes, stroke and Peripheral vascular disease had a significant wider and a positive ScvO2-SVO2 gradient as compared to patient with lower troponin surge(8.18±4.12 vs. 3.75±6.12 p=0.00673). Other parameters i.e. bypass time, cross clamp time, time to extubation, ICU stay, Cardiac index, PAOP no significant difference was found.ConclusionPersistently positive and wide ScvO2 - SVO2 Gradient can be used as direct evidence of myocardial ischemia in post CABG patients.
text/html2012-01-05T11:06:55+01:00http://www.webmedcentral.com/Dr. Deepak GuptaPre-Existing Isolated Diastolic Heart Dysfunction in Mechanically Ventilated Patient: Obscure Panic Attacks Pre-Intubation and Unexplained Delirium Post-Intubation
http://www.webmedcentral.com/article_view/2853
Delirium in intensive care units (ICUs) does not always represent underlying cerebral causes. We hereby present a difficult case of ICU delirium that was secondary to undiagnosed isolated diastolic heart dysfunction (IDHD). Delirium should be considered in the larger perspective of cardio-pulmonary-cerebral etio-pathogenesis with specific therapies directed to the specific inciting factors: for instance the agitations and panic attacks with associated oxygen desaturations in non-intubated patient with pre-existing IDHD should caution the ICU team to re-focus their patient management on the undiagnosed or undertreated IDHD before jumping onto the universal sedation/analgesia protocol for delirium management in the intubated ICU patient.text/html2012-01-05T11:05:11+01:00http://www.webmedcentral.com/Dr. Deepak GuptaIntra-Aortic Balloon Pump Deflation Generated Suction-like Forward Aortic Blood Flow and Auto-Triggering of a Flow-Triggered Mechanical Ventilator
http://www.webmedcentral.com/article_view/2854
Auto-triggering with the mechanical ventilators can be a problematic nuisance; however, it can be catastrophic too if the resultant respiratory alkalosis is not recognized early and treated with technical changes within the ventilatory mode and/or trigger settings of mechanical ventilation. We hereby present a postoperative case of a patient in which intra-aortic balloon pump (IABP) inflation-deflation cycle was triggering the mechanical ventilator. Intra-aortic balloon pump deflation generated suction-like forward aortic blood flow related auto-triggering of a flow-triggered mechanical ventilator should always be crossed off the checklist to correct the unexplained respiratory alkalosis in intensive care unit patients with cardiogenic shock who are either medically paralyzed or are on drug-induced paralysis (neuromuscular blockade).text/html2016-11-15T06:59:41+01:00http://www.webmedcentral.com/Dr. Deepak GuptaDoes Naloxone Infusion Improve Recovery from Delirium in Intensive Care Unit? A Worth Exploring Project Into An Uncharted Domain
http://www.webmedcentral.com/article_view/5225
Hypoactive delirium is difficult to differentiate from over-sedation and is often treated as such. However, hyperactive delirium with its agitation component is easily identified and differentiated by the Intensive Care Unit (ICU) personnel. This type of delirium irrespective of its underlying etiologies or risk factors may be reflective of overactive and dysrhythmic brain activity with potential excitatory neurotransmitters playing a role in the pathophysiology. Naloxone has been shown to decrease excitatory neurotransmitters in the cerebrospinal fluid. Based on this background, it would be worthwhile to investigate whether this low-dose continuous naloxone infusion has any role in decreasing the total duration of delirium in critically ill patients. Therefore, the objective of envisaged randomized placebo-controlled prospective study would be to assess if continuous low-dose naloxone infusion improves the recovery parameters of delirious patients in the ICU. The optimistic hope and expectation for the abovementioned results from the envisaged project is because although naloxone infusion has attained status of standard care to avoid and potentially treat perioperative spinal cord insult and injury, the naloxone infusion use for brain (the other or better half of the central nervous system) has NOT been explored at all until recently when Chinese researchers investigated into hepatic disease related brain dysfunction being managed by naloxone infusion. Therefore this uncharted domain should be explored and what can be a better model than hyperactive delirium model in ICU patients wherein trends in the response of agitation component to naloxone infusion will NOT only be easily recordable clinically but also if validated, can offer an additional tool in the armamentarium of ICU specialists for difficult to manage critically delirious patients. To summarize, naloxone infusion role in managing delirium is easy to explore and worth researching so that this non-costly drug may be able to find an alternate use (if validated) that would be able to prevent unprecedented losses/costs (personal, institutional and systematic) involved while managing delirious patients.