05 Jan 12
Posted in Fluid management at 21:58 by Laci
By S Kozek-Langenecker
Best Practice & Research Clinical Anaesthesiology 2009;23:225-236
Haemostatic alterations associated with the use of fluids are related to non-specific dilutional effects and colloid-specific effects, such as acquired von Willebrand syndrome, inhibition of platelet function and fibrin polymerization. Judging by currently available evidence, dextran, hetastarch and pentastarch have a more pronounced impact than tetrastarch, gelatin and albumin. In patients with hypocoagulability, tetrastarch appears to be a suitable volume expander due to its high safety index and volume efficacy. Gelatins have lower inhibitory effects on clot strength compared with tetrastarch, but their volume efficacy is also lower. Dextrans are potent anticoagulants with a high risk for adverse reactions. Albumin has negligible effects on haemostasis, but low volume efficacy and costs limit the use of a blood product as a routine volume replacement fluid. To avoid potential acidosis-induced changes in haemostasis, plasma-adapted carrier solutions may be used instead of saline-based solutions.Haemostatic alterations associated with the use of fluids are related to non-specific dilutional effects and colloid-specific effects, such as acquired von Willebrand syndrome, inhibition of platelet function and fibrin polymerization. Judging by currently available evidence, dextran, hetastarch and pentastarch have a more pronounced impact than tetrastarch, gelatin and albumin. In patients with hypocoagulability, tetrastarch appears to be a suitable volume expander due to its high safety index and volume efficacy. Gelatins have lower inhibitory effects on clot strength compared with tetrastarch, but their volume efficacy is also lower. Dextrans are potent anticoagulants with a high risk for adverse reactions. Albumin has negligible effects on haemostasis, but low volume efficacy and costs limit the use of a blood product as a routine volume replacement fluid. To avoid potential acidosis-induced changes in haemostasis, plasma-adapted carrier solutions may be used instead of saline-based solutions.
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02 Jan 12
Posted in Anesthesia, Pre-operatie evaluation at 18:08 by Laci
By A R. Tait and S Malviya
Anesth Analg January 2005 100:59-65;
One of the most controversial issues in pediatric anesthesia has revolved around the decision to proceed with anesthesia and surgery for the child who presents with an upper respiratory tract infection (URI). In the past, doctrine dictated that children with URIs have their surgery postponed until the child was symptom free. This practice was based on the empirically supported premise that anesthesia increased the risk of serious complications and complicated the child’s postoperative course. Although recent clinical data confirm that some children with URIs are at increased risk of perioperative complications, these complications can, for the most part, be anticipated, recognized, and treated. Although the child with a URI still presents a challenge, anesthesiologists are now in a better position to make informed decisions regarding the assessment and management of these children, such that blanket cancellation has now become a thing of the past.
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30 Dec 11
Posted in Anesthesia, Laparoscopic surgery at 1:01 by Laci
By R Jokela, J Ahonen, M Tallgren, P Marjakangas, K Korttila
Anesth Analg 2009;109:607-615
Apart from being antiemetic, glucocorticoids have an analgesic property. The optimal dose of dexamethasone in the management of pain after surgery has not been established. In this placebo-controlled, dose-finding study, we evaluated the analgesic effect of three doses of dexamethasone after laparoscopic hysterectomy.
Methods
We randomized 129 women scheduled for laparoscopic hysterectomy to receive placebo, dexamethasone 5 mg (D5), 10 mg (D10), or 15 mg (D15) IV before the induction of anesthesia. The patients were anesthetized with propofol and remifentanil in a standardized manner. Until the first postoperative morning, postoperative pain was managed with IV oxycodone using patient-controlled analgesia. The visual analog scale scores for pain and side effects, and the amounts of the analgesics were recorded for 3 days after surgery.
Results
The total dose of oxycodone (0–24 h after surgery) was smaller in the D15 (0.34 mg/kg [0.11–0.87]) group than in the placebo group (0.55 mg/kg [0.19–1.13]) (P = 0.003). The doses of oxycodone during Hours 0–2 after surgery were smaller in the D10 (0.17 mg/kg [0.03–0.36]) and D15 (0.17 mg/kg [0.03–0.35]) groups than in the placebo (0.26 mg/kg [0.10–0.48]) (P = 0.001, D10 versus placebo; P < 0.001, D15 versus placebo) group. During Hours 2–24 after surgery, however, the doses of oxycodone were equal in the placebo, D5, D10, and D15 groups (0.31 mg/kg [0.03–0.78], 0.22 mg/kg [0.03–0.92], 0.24 mg/kg [0.05–0.87], and 0.20 mg/kg [0–0.65], respectively). The visual analog scale scores for pain at rest, in motion, or at cough did not differ in the study groups. The incidence of dizziness was lower in the D15 group than in the placebo group (P = 0.001), the D5 group (P = 0.006), and the D10 group (P = 0.030) during the first 24 h after surgery. During the later course of recovery, the incidence of dizziness did not differ among the four study groups.
Conclusions
IV dexamethasone 15 mg before induction of anesthesia decreases the oxycodone consumption during the first 24 h after laparoscopic hysterectomy. During first 2 h after surgery, dexamethasone 10 mg reduces the oxycodone consumption as effectively as the 15 mg dose.
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29 Dec 11
Posted in Anesthesia, Echocardiography, Laparoscopic surgery at 2:02 by Laci
By Mario R. Concha, V Mertz, L I Cortínez, K A González, J Butte
Anesth Analg 2009;109:114-118
Pulse wave analysis (PWA) allows cardiac output (CO) measurement after calibration by transpulmonary thermodilution. A PWA system that does not require previous calibration, the FloTrac/Vigileo (FTV), has been recently developed. We compared determinations of CO made with the FTV to simultaneous measurements using transesophageal echocardiography (TEE).
Methods
Ten ASA I-II patients scheduled for laparoscopic colorectal surgery were studied. A radial 20-gauge cannula was inserted and connected to a hemodynamic monitor and a FTV system for PWA and determination of CO (COPWA). TEE CO (COTEE) was determined as previously described. Measurements were made after intubation, 5 min after establishing the lithotomy position, 5 min after establishing pneumoperitoneum, every 30 min, or each time mean arterial blood pressure decreased below basal values. Statistical analysis was made with the Bland and Altman method.
Results
Eighty-eight measurements were compared. The COTEE values ranged from 3.23 to 12 Lt/min (mean 6.21 ± 1.85). Values for COPWA ranged from 2.9 to 8.5 Lt/min (mean 4.84 ± 1.14). Bias was 1.17 and limits of agreement −2.02 and 4.37. The percentage error between all COTEE and COPWA measurements was 40% (27%-50%) mean (range).
Conclusions
During laparoscopic colon surgery, clinically important differences were observed between CO determinations made with TEE and FTV.
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