17 Jan 12
Posted in Anesthesia at 1:50 by Laci
By K Hirota and D Lambert
Br. J. Anaesth. (2011) 107 (2): 123-126.
In 1996, we published an editorial ‘Ketamine, mechanism(s) of action and unusual clinical uses’ in the British Journal of Anaesthesia. In that editorial, we described the pharmacology of ketamine including bronchodilator, anti-shock, and neuroprotective actions along with some unusual clinical applications. The editorial has been cited more than 130 times in total with around 10 citations every year, which implies that ketamine is still of interest to a wide audience. However, as ketamine anaesthesia is associated with cardiovascular hyperdynamics and disturbing emergence reactions, this agent is often avoided, despite the ease with which these adverse reactions can be prevented by pre-administration, co-administration of sedatives, or both such as benzodiazepines, propofol, dexmedetomidine, or droperidol.
In the past 15 yr, ketamine has been reported to possess several new clinically beneficial properties such as potentiation of opioid analgesia, prevention of opioid-induced acute tolerance and spinal ischaemia, anti-inflammatory actions, preventive effects on recall and awareness during general anaesthesia, and anti-tumour actions. In this ‘update’ editorial, we have focused on these potential clinical advantages of ketamine.
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14 Jan 12
Posted in Anesthesia, Obesity at 1:01 by Laci
By A S Eichenberger, S Proietti, S Wicky, P Frascarolo, M Suter, D R Spahn, L Magnusson
Anesth Analg 2002;95:1788-1792
Perturbation of respiratory mechanics produced by general anesthesia and surgery is more pronounced in morbidly obese (MO) patients. Because general anesthesia induces pulmonary atelectasis in nonobese patients, we hypothesized that atelectasis formation would be particularly significant in MO patients. We investigated the importance and resorption of atelectasis after general anesthesia in MO and nonobese patients. Twenty MO patients were anesthetized for laparoscopic gastroplasty and 10 nonobese patients for laparoscopic cholecystectomy. We assessed pulmonary atelectasis by computed tomography at three different periods: before the induction of general anesthesia, immediately after tracheal extubation, and 24 h later. Already before the induction of anesthesia, MO patients had more atelectasis, expressed in the percentage of the total lung area, than nonobese patients (2.1% versus 1.0%, respectively; P < 0.01). After tracheal extubation, atelectasis had increased in both groups but remained significantly more so in the MO group (7.6% for MO patients versus 2.8% for the nonobese; P < 0.05). Twenty-four hours later, the amount of atelectasis remained unchanged in the MO patients, but we observed a complete resorption in nonobese patients (9.7% versus 1.9%, respectively; P < 0.01). General anesthesia in MO patients generated much more atelectasis than in nonobese patients. Moreover, atelectasis remained unchanged for at least 24 h in MO patients, whereas atelectasis disappeared in the nonobese.
Implications
We compared the resolution over time of pulmonary atelectasis after a laparoscopic procedure by performing computed tomography scans in two different groups of patients: 1 group had 10 nonobese patients, and in the other group there were 20 morbidly obese patients.
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11 Jan 12
Posted in Anesthesia, Regional anaesthesia at 1:45 by Laci
By S K Ramachandran, P Picton, A Shanks, P Dorje and J Pandit
Br. J. Anaesth 2011;107:157-163
Carotid endarterectomy surgery can be performed under regional anaesthesia alone or under general anaesthesia. However, there are several types of regional block available and reported complication rates after superficial cervical plexus blocks are significantly lower than deep blocks. It is not known if subcutaneous and intermediate blocks are equally effective, although anatomical evidence suggests that the latter (where the injectate diffuses below the deep cervical fascia) might provide superior quality of intraoperative anaesthesia.
Methods
Forty-four patients were randomized to receive either subcutaneous or intermediate cervical plexus blocks for carotid endarterectomy. The primary endpoint was supplemental lidocaine requirement during surgery. Secondary outcome measures included: total amount of fentanyl administered during surgery, recall of pain scores during surgery, complications, and patient and surgeon satisfaction.
Results
There was no statistically significant difference for median (range) lidocaine supplementation between the subcutaneous and intermediate groups 65 (20–170) mg vs 85 (30–345) mg, respectively; P=0.31. There were no statistical differences in the secondary outcome measures and no major complications during the study.
Conclusions
Intermediate and subcutaneous cervical plexus blocks are equally effective for carotid endarterectomy. This study adds to the body of evidence supporting the safe use of superficial blocks for this type of surgery.
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09 Jan 12
Posted in Anesthesia, Neuraxial block at 1:41 by Laci
By A Gupta, A Björnsson, M Fredriksson, O Hallböök and C Eintrei
Br. J. Anaesth 2011;107:164-170
There is some evidence that epidural analgesia (EDA) reduces tumour recurrence after breast and prostatic cancer surgery. We assessed whether EDA reduces long-term mortality after colorectal cancer surgery.
Methods
All patients having colorectal cancer surgery between January 2004 and January 2008 at Linköping and Örebro were included. Exclusion criteria were: emergency operations, laparoscopic-assisted colorectal resection, and stage 4 cancer. Statistical information was obtained from the Swedish National Register for Deaths. Patients were analysed in two groups: EDA group or patient-controlled analgesia (PCA group) as the primary method of analgesia.
Results
A total of 655 patients could be included. All-cause mortality for colorectal cancer (stages 1–3) was 22.7% (colon: 20%, rectal: 26%) after 1–5 yr of surgery. Multivariate regression analysis identified the following statistically significant factors for death after colon cancer (P<0.05): age (>72 yr) and cancer stage 3 (compared with stage 1). A similar model for rectal cancer found that age (>72 yr) and the use of PCA rather than EDA and cancer stages 2 and 3 (compared with stage 1) were associated with a higher risk for death. No significant risk of death was found for colon cancer when comparing EDA with PCA (P=0.23), but a significantly increased risk of death was seen after rectal cancer when PCA was used compared with EDA (P=0.049) [hazards ratio: 0.52 (0.27–1.00)].
Conclusions
We found a reduction in all-cause mortality after rectal but not colon cancer in patients having EDA compared with PCA technique.
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