Friday, January 11, 2008
Changeovers of vasoactive drug infusion pumps
Hemodynamic instability during the changeover of vasoactive infusion pump (CVIP) is a common site in ICUs. Interesting article published very recently in Critical Care 1 in which the impact of a "quick change method" of CVIP (2 syringes) was assessed and compared with regular (single syringe) method.
Study was done (compared) in 2 phases.
Phase 1: In this phase, nurses were free to choose the method of changeover of CVIP they usually practice.
Phase 2: In this phase, strategy called “quick change method” is applied. using two syringe drivers. This consisted loading the new infusion with a new line into a new syringe pump, and priming the line when the running infusion was about to finish. Nurses started the pump and chose a high flow rate until a drop of vasoactive drug appeared on the end of the line, in order to avoid a start up delay. Next, they programmed the pump to same rate and setting as the previous infusion. After that, they removed the cap from the spare port of the three-way stopcock and connected it the new infusion pump. Then, they turned the three-way stopcock on to the new infusion, which closed the lumen of the old infusion. Lastly, they had to disconnect the old infusion and put a cap on the new spare port.
913 changeovers of infusion pumps were evaluated: 435 in phase 1 and 478 in phase 2.
Results: The frequency of incidents was significantly reduced in phase 2 (5.9%, n=28) versus phase 1 (17.8%, n=78) with 98% of incidents were blood pressure variations.

References: click to get abstract / article
1. Changeovers of vasoactive drug infusion pumps: impact of a quality improvement program - pdf file, Critical Care 2007, 11:R133
Thursday, January 10, 2008
Q; Which beta-blocker is prone to cause life-threatening hyperkalemia particularly in kidney transplant patient?
A; Labetalol
One of the relatively unknow and fortunately benign side effect of beta-blockers is hyperkalemia. Most of the hyperkalemia is benign particularly with cardio-selective b-blockers. But life-threatening hyperkalemia may occur after IV dose of labetalol, particularly in patients with chronic renal failure, hemodialysis patients and post kidney transplant patients.
References: click to get abstract / article
1. Labetalol-Induced Hyperkalemia in Renal Transplant Recipients , American Journal of Nephrology 2002;22:347-351
2. Possible Metoprolol-Induced Hyperkalemia, Journal of Pharmacy Practice, Vol. 19, No. 5, 320-325 (2006)
Wednesday, January 9, 2008
Q; Which 2 very commonly used medicines, physicians prescribe simultaneously and probably reflexly - but they cancel each other effects ?
A; β-blockers and Dobutamine (while trying to control tachycardia of dobutamine by b-blockers)
Dobutamine is a selective β1 adrenergic agonist and its effect get neutralize by β-blockers.
Atenolol, Esmolol, Metoprolol are β1 blockers
Carvedilol, Labetalol and Nadolol are β1, β2 blockers
Tuesday, January 8, 2008
VATS conversion to a standard thoracotomy
Q; In how many cases VATS (Video-Assisted Thoracic Surgery)require intraoperative conversion to a standard thoracotomy ?
A; In approximately 20% of patients undergoing VATS, intraoperative conversion to a standard thoracotomy will be necessary for any of several reasons, including extensive pleural adhesions and pulmonary lesions that cannot be located thoracoscopically or that necessitate a more extensive resection than can be accomplished endosurgically.
(so keep fingers cross once you send your patient to OR)
Monday, January 7, 2008
Mucomyst - does it work ? - yes, no, yes, no ?
Helps kidney or lung or liver ?
Since landmark 2000 article of NEJM 1 on benefit of antioxidant, N-acetylcysteine (mucomyst) on prevention of acute renal failure in many clinically stress situations, it has almost became a standard of practice. Since than though many studies failed to show its benefit and strictly from evidence based medicine, it has yet to prove its role !
This month, another study published from Italy in Critical Care Medicine 2, on benefit of N-acetylcysteine for prevention of acute renal failure in patients with chronic renal insufficiency undergoing cardiac surgery.
Randomized, placebo-controlled, prospective study of 254 consecutive patients with chronic renal insufficiency (estimated cr. cl. less than or = 60 mL/min) undergoing elective cardiac surgery wwas done. Patients were randomized into 2 groups
- to receive N-acetylcysteine (n = 129). Patients of the N-acetylcysteine group received four boluses of intravenous N-acetylcysteine (1200 mg every 12 hrs, starting immediately before cardiac surgery).
- or placebo (n = 125)
Postoperative acute renal failure is defined as more than 25% increase in serum creatinine from baseline.
Results:
- Acute renal failure occurred in occurred in 52% of control patients and 40% of N-acetylcysteine-treated patients (p = .06)
- In-hospital mortality and need for renal replacement therapy were not affected by N-acetylcysteine
- N-acetylcysteine-treated patients required less days of mechanical ventilation prolonged for >48 hrs (3% vs. 18%; p < .001)
- N-acetylcysteine-treated patients had lower incidence of prolonged stay in intensive care unit stay, defined as more than 4 days (13% vs. 33%; p < .001)
Conclusions:
Though IV mucomust does not clearly prevent postoperative acute renal failure in patients with renal insufficiency undergoing cardiac surgery, it suggests a positive effect of NAC on pulmonary function that influences a patient's clinical course by having lower days of mechanical ventilation and so lower ICU-LOS !
Editors' comment: Use it !
Related previous pearls:
Double the dose of mucomyst? ,
Contrast induced Nephropathy and
Preventing contrast-Induced Nephropathy - use of sodium bicarbonate
References: click to get abstract / article
1. Prevention of Radiographic-Contrast-Agent–Induced Reductions in Renal Function by Acetylcysteine - N Engl J Med 343:180, July 20, 2000
2. N-acetylcysteine for prevention of acute renal failure in patients with chronic renal insufficiency undergoing cardiac surgery: A prospective, randomized, clinical trial - Critical Care Medicine. 36(1):81-86, January 2008
Sunday, January 6, 2008
Levaquin dosing in renal failure
Q; What's the dose adjustment of Levaquin (levofloxacin) in Hemodialysis or Chronic Ambulatory Peritoneal Dialysis (CAPD) as well as CVVHD patients?
A; For Hemodialysis, CAPD and with creatinine clearance less than 20 mL/min, dose of levofloxacin is 250 mg per 48 hours. In HD patients, dose should be given after HD session.
For CVVHD levaquin should be given as 250 mg/day as there is some clearance via CVVHD.
References: click to get abstract / article
1. Levaquin - Rxlist.com
2. Pharmacokinetics of Levofloxacin and Ciprofloxacin during Continuous - Renal Replacement Therapy in Critically Ill Patients (pdf) - ANTIMICROBIAL AGENTS AND CHEMOTHERAPY, Oct. 2001, p. 2949–295
Saturday, January 5, 2008
Saturday January 5, 2008
Ok to fresh frozen plasma but male-donor-only please !!
In July 2003 the English Blood Service stopped using female donor plasma for the manufacture of fresh frozen plasma (FFP). Transfusion-related acute lung injury (TRALI), due to plasma from female donors containing antileucocyte antibodies, is allegedly a contributor to the development of acute lung injury (ALI). To confirm above hypothesis, a before-and-after, observational (single-centre) study was performed on 211 consecutive patients undergoing open repair of a ruptured AAA over 8 years period (1998 to 2006).
Primary outcome was development of ALI (PaO2/FiO2 < color="#003333">Secondary outcomes were time to extubation, and survival at 30 days.
Results
Primary outcome: There was significantly less ALI following the change to male-only FFP (36% before vs 21% after, P = 0.042). Secondary outcomes: were not statistically different between groups.
Patients with ALI in either group had a poorer 30-day survival (59% vs 80%, P = 0.005).
Conclusion:
Exclusion of female-donor FFP was associated with a statistically significant reduction in the incidence of ALI (in patients undergoing repair of a ruptured AAA).
Reference: click to get abstract / article
1. The effect of male-donor-only fresh frozen plasma on the incidence of acute lung injury following ruptured abdominal aortic aneurysm repair - Freeman Hospital and National Blood Service, Newcastle upon Tyne, UK - from 27th International Symposium on Intensive Care and Emergency Medicine Brussels, Belgium. 27–30 March 2007, Critical Care 2007, 11(Suppl 2):P374
Friday, January 4, 2008
5 things to eye ball on TEG (Thromboelastogram)
Please also see our previous pearl What is TEG
Read with diagram below along with normal values
r - reaction time - from start of test to initial clot formation. Prolonged with clotting factor deficiencies and heparin.
a - Ang or alpha angle - it assesses rate of clot formation and decreased in the presence of clotting factor deficiencies, platelet dysfunction, thrombocytopenia, and hypofibrinogenaemia.
K - is a measure of time from beginning of clot formation until the amplitude of thromboelastogram reaches 20 mm, and represents the dynamics of clot formation.
MA - maximum amplitude - the widest point of the traceing on vertical or Y-axis . It represents maximum clot strength and is reduced with platelet dysfunction.
LY 30 or lysis 30 - is the percentage decrease in amplitude 30 min after MA, measures the degree of fibrinolysis. (see bending curves in b below)
References: click to get abstract / article
1. Thromboelastography / Thromboelastometry (pdf file) (ref: Clin. Lab. Haem. 2005, 27, 81–90)
2. Management of coagulation during cardiopulmonary bypass (pdf file) (ref: Continuing Education in Anaesthesia, Critical Care & Pain Volume 7 Number 6 2007)
Thursday, January 3, 2008
Anticoagulation Medications - sites of action
A very simple diagram to show at what level basic 4 groups of anticoagulation medicines strike their effect.
Heparins - UFH and LMWH - are antithrombin
Warfarin - Warfarin inhibits the synthesis of biologically-active forms of the vitamin K-dependent clotting factors II, VII, IX and X, as well as the regulatory factors protein C, protein S, and protein Z.
Direct thrombin inhibitors (DTIs) - Hirudin, Lepirudin, Bivalirudin, Argatroban etc. - are a new class of anticoagulants that bind directly to thrombin and block its interaction with its substrates.
Thrombolytics - streptokinase, urokinase, alteplase, rtPA, reteplase, tenecteplase - works by activating the enzyme plasminogen, which clears the cross-linked fibrin mesh.
