Early and late recovery after major abdominal surgery. Comparison between propofol anaesthesia with and without nitrous oxide and isoflurane anaesthesia.
Department of Anaesthesiology, Faculty of Health Sciences, University Hospital, Linköping, Sweden.
A comparison was made between early and late recovery after major abdominal surgery under intravenous anaesthesia with propofol (with and without nitrous oxide) or inhalational anaesthesia with isoflurane. Sixty patients were randomly allocated to one of three forms of anaesthesia: propofol, propofol/nitrous oxide, or isoflurane/nitrous oxide anaesthesia. All received fentanyl and vecuronium. Recovery was monitored during the first 2 h after extubation and on days 1, 2, 3, 7 and 30 after surgery. Every 30 min during the first 2 postoperative hours, the Steward recovery scale, sedation, orientation, collaboration, and comprehension were assessed by a blinded observer. Psychomotor function was evaluated by computerised simple reaction time and finger tapping speed in 32 patients. A scale of symptoms and mood check list were filled in by 35 patients on days 1, 2, 3, 7 and 30. The preoperative values for all tests were collected 1-4 days before surgery. The time between end of surgery and extubation was longer in the propofol group, but early and late recovery of psychomotor function were similar in the three groups. Patients anaesthetised with isoflurane reported more vegetative symptoms than those who received propofol (P < 0.03). The addition of nitrous oxide to propofol did not change the reported degree of symptoms. The difference in vegetative symptoms between groups was most obvious on day 7. Patients anaesthetised with propofol reported better subjective control (P < 0.02) and were more socially oriented (P < 0.05) than patients anaesthetised with isoflurane. We conclude that early recovery was similar in the three groups.(ABSTRACT TRUNCATED AT 250 WORDS)
Department of Anesthesiology, Korea University Guro Hospital, Seoul, Republic of Korea.
BACKGROUND We have previously demonstrated that aged rats have persistent impairment of spatial memory after sedation with nitrous oxide or general anesthesia with isoflurane-nitrous oxide. Propofol has different receptor mechanisms of action and a favorable short-term recovery profile, and it has been proposed that propofol is devoid of enduring effects on cognitive performance. No studies have investigated this question in aged subjects, however, so we designed an experiment to examine the long-term effects of propofol anesthesia on spatial working memory. METHODS Eighteen-mo-old rats were randomized to 2 h of 100% oxygen-propofol anesthesia (n=11) or to a control group that breathed 100% oxygen (n=10). Propofol was administered by continuous infusion via a tail vein catheter. Rats breathed spontaneously and rectal temperature was maintained. Mean arterial blood pressure was measured noninvasively and a venous blood gas was obtained just before discontinuation of propofol. After a 2-day recovery, spatial working memory was assessed for 14 days using a 12-arm radial maze. The number of total errors, number of correct choices to first error, and time to complete the maze was recorded and analyzed using a repeated measure analysis of variance (ANOVA), with P<0.05 being considered statistically significant. RESULTS The average propofol infusion rate was 0.6+/-0.1 mg.kg (-1).min(-1), a rate corresponding to a 50% effective concentration dose in adult rats. Mean arterial blood pressure during anesthesia was 100+/-2 mm Hg and venous blood gases remained in the normal range. There was no difference between the control and previously anesthetized rats on any measure of radial arm maze performance, indicating propofol anesthesia produces no lasting impairment in spatial working memory in aged rats. CONCLUSIONS In aged rats, propofol anesthesia is devoid of the persistent memory effects observed with other general anesthetics in this model. Thus, while it appears that the state of general anesthesia is neither necessary nor sufficient for development of postanesthetic memory impairment, the choice of anesthetics may play a role in late cognitive outcome in the aged.
Anaesthesia for day case excisional breast biopsy: propofol-remifentanil compared with sevoflurane-nitrous oxide.
Yonsei University College of Medicine, Severance Hospital, Anesthesia and Pain Research Institute, Department of Anesthesiology and Pain Medicine, Seoul, South Korea. email@example.com
BACKGROUND AND OBJECTIVE A randomized and prospective study was performed to compare anaesthetic characteristics and stress hormone responses of two anaesthetic techniques. METHODS Forty-two patients undergoing day case excisional biopsy of breast mass were randomly assigned to receive propofol-remifentanil or sevoflurane-N2O. Anaesthesia was induced and maintained either with sevoflurane and 50% N2O in oxygen or with target-controlled remifentanil and propofol in 50% oxygen and air. Anaesthetic depth was monitored by the bispectral index. RESULTS The times for induction (2.9 vs. 1.7 min) and for laryngeal mask insertion (5.7 vs. 3.3 min) were longer in the sevoflurane-N2O group than in the propofol-remifentanil group. However, apnoea (57.1% vs. 9.5%) and bradycardia (23.8% vs. 0%) were more prevalent with propofol-remifentanil. In the sevoflurane-N2O group, the emergence times to a verbal response (10.6 vs. 3.7 min), to extubation (11.8 vs. 4.0 min) and to orientation (14.7 vs. 4.8 min) were longer than in the propofol-remifentanil group. There were significantly more nausea (38.1% vs. 4.8%) and vomiting (19.2% vs. 0%) in the sevoflurane-N2O group than in the propofol-remifentanil group. The time to discharge was similar although there was less postoperative pain in the sevoflurane-N2O group. There were no differences in the perioperative cortisol responses in the two groups. CONCLUSIONS Smoother induction of anaesthesia was seen with sevoflurane-N2O. Propofol-remifentanil showed a quicker emergence with less nausea/vomiting. There were similar perioperative cortisol responses in the two anaesthetic techniques.
University of Göttingen, Department of Anaesthesiology, Göttingen, Germany. firstname.lastname@example.org
BACKGROUND AND OBJECTIVE: There are anecdotal reports of dysphoria occurring in patients on the first day after anaesthesia with remifentanil. This study was performed to investigate this allegation and to find a possible relationship to postoperative shivering or to nausea and vomiting. METHODS: Patients undergoing otorhinolaryngeal surgery took part in a prospective, randomized, double-blind study comparing total intravenous anaesthesia with propofol (2 mg kg(-1) bolus injection then 100 microg kg(-1) min(-1)) and remifentanil (1 microg kg(-1) bolus then 0.1-0.5 microg kg(-1) min-1) or alfentanil (30 microg kg(-1) bolus then 0.16-0.83 microg kg((-1) min(-1)). The patients were carefully insulated and actively warmed by convective heating and rectal temperature was monitored continuously. Postoperative shivering was graded on a three-point scale, and the cumulative incidence of nausea and vomiting were registered at 24 h after surgery. Pre- and postoperative mood was measured with the von Zerssen mood scale (Befindlichkeits-Skala) and changes tested for significance. High scores reflect discontent and dysphoria. RESULTS: The data of 98 patients (49 in each group, ASA I-II, age 42 +/- 13 yr, anaesthesia time 141 +/- 60 min; mean +/- SD; intergroup P values > 0.1) were evaluated. Core temperature did not change perioperatively (before 36.6 +/- 0.2 degrees C; after 36.8 +/- 0.3 degrees C, inter- and intragroup P > 0.1). The incidence of nausea was the same in each group; vomiting occurred with equal frequency (6/49 vs. 7/49). Shivering was significantly more frequent after remifentanil (41% vs. 10%, P < 0.001). The patients' mood remained stable after remifentanil but worsened after alfentanil (von Zerssen score from 9.3 +/- 2.5 to 13.9 +/- 3.6; mean +/- 95% confidence intervals; P < 0.01). DISCUSSION: Postoperative shivering was more frequent after remifentanil but was unrelated to intraoperative heat loss. Contrary to preliminary informal observations, there was no evidence that remifentanil caused postanaesthetic dysphoria on the day one after surgery.
Perioperative Medicine and Ambulatory Anesthesia, University of Texas Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, TX 75235-9068, USA. email@example.com
In the current health care environment, anesthesia practitioners are frequently required to reevaluate their practice to be more efficient and cost-effective. Although IV induction with propofol and inhalational induction with sevoflurane are both suitable techniques for outpatients, patients prefer IV induction. Maintenance of anesthesia with the newer inhaled anesthetics (ie, desflurane and sevoflurane) provide for a rapid early recovery as compared with infusion of propofol (ie, TIVA), while allowing easy titratability of anesthetic depth. Titration of hypnotic sedatives using BIS monitoring may reduce the time to awakening and thereby may facilitate fast tracking (ie, bypassing the PACU) and reduce hospital stay. Inhalational anesthesia is associated with a higher incidence of PONV, but no differences have been demonstrated with respect to late recovery (eg, PACU stay and home readiness). Although clinical differences between desflurane and sevoflurane appear to be small, desflurane may be associated with faster emergence, particularly in elderly and morbidly obese patients. Balanced anesthesia with IV propofol induction and inhalation anesthesia with N2O for maintenance, and an LMA for airway management, may be an optimal technique for ambulatory surgery. Inhalational anesthesia may have an economic advantage over a TIVA technique.
AANA J. 2000 Apr ;68 (2):135-40 10876460
An investigation of the effect of 2 sedation regimens on patient mood state following upper extremity surgery using local anesthesia.
Mayo Clinic, Rochester, Minn., USA.
Sedation techniques for patients undergoing minor outpatient surgery frequently include a variety of intravenous agents. The present study was designed to look for differential effects of 2 different sedation regimens on perioperative mood states. Twenty-two patients undergoing upper extremity surgery using local anesthesia were randomized to receive either propofol or midazolam intravenously for intraoperative sedation. Subjects were asked to complete a Profile of Mood States survey before and after surgery. The results of this survey were examined for differences in mood between the 2 groups that may be attributable to differences in drug effect. No significant differences were identified between propofol or midazolam regarding their effect on patient mood. Patients in both groups experienced a reduction in perioperative anxiety.
Influence of thiopental and propofol on postoperative cognitive recovery in the elderly patient undergoing general anesthesia.
Department of Anesthesiology and Intensive Care, Meir Hospital, Kfar Saba, Israel.
STUDY OBJECTIVE To assess mental and psychomotor recovery following induction of anesthesia with thiopental or propofol in elderly patients undergoing general anesthesia. DESIGN Randomized, prospective, double-blind study. SETTING Large referral hospital. PATIENTS 40 elderly patients ASA physical status I-III (> 65 years) undergoing abdominopelvic surgery with an estimated surgical time of at least 90 minutes. INTERVENTIONS All patients received combined epidural-general anesthesia. After establishing a T6 sensory blockade, patients were randomized to receive either thiopental or propofol for induction of general anesthesia. The induction drug was slowly titrated until loss of eyelash reflex was noted. Thereafter, all patients received desflurane (2% to 3% end-tidal) and 70% nitrous oxide (N2O) in oxygen for maintenance of general anesthesia. To facilitate tracheal intubation, intravenous alfentanil 10 micrograms/kg and atracurium 0.4 mg/kg were administered. Perioperative analgesia was maintained with epidural bupivacaine. MEASUREMENTS AND MAIN RESULTS A digit substitution test (DSST) and shape-sorter test, as well as patient-generated 100-mm visual analog score (VAS; 0 = minimal and 100 = maximal) for anxiety, sleepiness, and coordination, were performed during the preanesthetic interview, on postanesthesia care unit admission, and at 15, 45, 90, and 120 minutes thereafter. To induce loss of consciousness, either thiopental 2.5 +/- 1.0 mg/kg or propofol 1.6 +/- 0.6 mg/kg was administered. The mean anesthetic time was 109 +/- 30 minutes and 114 +/- 38 minutes for the thiopental and propofol groups, respectively. Emergence, extubation, and orientation times, as well as time to follow commands, were unaffected by patient randomization. Similarly, the DSST and shape-sorter tests, in addition to the patient-generated VAS for pain, anxiety, and coordination, were similar among groups. However, irrespective of treatment modality, return to baseline digit substitution and shape-sorter scores were significantly delayed (p < 0.01). CONCLUSION When compared to thiopental, propofol does not facilitate improved cognitive recovery in geriatric patients undergoing prolonged surgery.
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Department of Anaesthesiology, University Hospital, Linköping, Sweden.
BACKGROUND: Opioid receptors have been demonstrated on peripheral afferent nerves throughout the body. The aim of the present study was to compare the effects of intravenous and intraperitoneal administration of morphine with regard to pain, postoperative morphine requirement, and recovery after major abdominal surgery, and to describe the pharmacokinetics of intraperitoneal morphine in humans. METHODS: In a double-blind manner, 30 patients scheduled for major abdominal surgery were randomized to either 50 mg of morphine intravenously (i.v.) or 50 mg of morphine intraperitoneally (i.p.) before operation. Pain was measured on a visual analogue scale and morphine requirements were registered for 3 days. Recovery was measured as time to oral intake of food, time to flatulence and days in hospital. Plasma morphine, morphine-3-glucuronide, and morphine-6-glucuronide concentrations were determined during the first 4 h after morphine administration. RESULTS: During the first postoperative hours there was less pain at rest (P = 0.02) and on coughing (P = 0.004) in the intravenous group. The requirement of additional morphine (P = 0.016) was lower in the intravenous group during the first postoperative day. No major differences in recovery were seen. The plasma concentrations of morphine measured as area under the curve (AUC) during the first 4 h were similar, but the intravenous group showed significantly higher concentrations of the active metabolite morphine-6-glucuronide,(P = 0.016), indicating a difference in pharmacokinetics after intraperitoneal compared to intravenous administration of morphine. CONCLUSION: Intraperitoneal administration of 50 mg of morphine before major abdominal surgery is less efficient in reducing pain and postoperative morphine requirements than the same amount of morphine given intravenously.
Atelectasis and oxygenation in major surgery with either propofol with or without nitrous oxide or isoflurane anaesthesia.
Forty-two patients undergoing major colonic surgery were assigned at random to receive isoflurane-fentanyl anaesthesia with nitrous oxide in oxygen, propofol-fentanyl anaesthesia with air in oxygen or propofol-fentanyl anaesthesia with nitrous oxide in oxygen. The groups were comparable in demographic data. Atelectases were identified, and the area measured by computerised tomography of the chest 203 +/- 69 min after extubation, and oxygenation was determined by arterial blood gas samples taken during operation at 30, 60, 90 and 120 min after extubation and on postoperative days 1, 2 and 3. Atelectases were seen in all three groups with no differences in the mean area between groups. After operation, the effect of 4 l.min-1 of oxygen by nasal catheter on PaO2 was similar in all groups. A significant decrease in PaO2 was found during the first 3 days after surgery, and was also the same in all groups. There was no correlation between area of atelectasis and postoperative PaO2. We conclude there is no difference in the incidence of postoperative atelectasis or oxygenation when using propofol, with or without nitrous oxide or isoflurane.
Department of Anaesthesiology, Faculty of Health Sciences, Linköping University Hospital, Sweden.
Sixty patients, ASA I-III, presenting for elective colonic surgery were studied to assess the stability of blood pressure and heart rate during anaesthesia with three equally potent anaesthetic techniques. Patients in group I (n = 20) received thiopentone induction, isoflurane and nitrous oxide; patients in group II (n = 20) received total intravenous anaesthesia with propofol; and patients in group III (n = 20) received intravenous propofol supplemented with nitrous oxide. Fentanyl and vecuronium were used in all three groups. The depth of anaesthesia was judged on clinical signs of adequate anaesthesia. Episodes of bradycardia (heart rate < 50 beats min-1), tachycardia (heart rate > 90 beats min-1), hypotension (mean arterial pressure > or = 30% below pre-operative blood pressure) or hypertension (mean arterial pressure > 30%, or systolic blood pressure > 15 mmHg, above pre-operative value) were recorded when lasting > 5 min. Any use of ephedrine or glycopyrrolate given to correct hypotension or bradycardia was documented: In group II, significantly more patients were given ephedrine (P < 0.01) to treat hypotension. The drug was administered after intubation but before skin incision in the majority of cases (9/11). Glycopyrrolate was given to significantly more patients in group III (P < 0.025) to treat bradycardia, and in 21 of a total of 34 patients given glycopyrrolate it was administered before surgery. With the use of these additional drugs, there were no differences in the number of patients with 5 min episodes of hypotension, hypertension, tachycardia or bradycardia.(ABSTRACT TRUNCATED AT 250 WORDS)
Anaesthetic technique does not influence postoperative bowel function: a comparison of propofol, nitrous oxide and isoflurane.
Department of Anaesthesiology, Faculty of Health Sciences, University Hospital Linköping, Sweden.
The aim of this study was to evaluate the influence of propofol, nitrous oxide and isoflurane on recovery, postoperative bowel function and postoperative complications after major gastrointestinal surgery. Sixty patients undergoing elective colonic operations were included in the study. They were randomly allocated to anaesthesia with isoflurane-nitrous oxide, propofol-air, or propofol-nitrous oxide, with fentanyl and vecuronium being used in all three groups. The same anaesthetic and surgical teams performed all the operations. The postoperative course was judged once each day by the Acute Physiology Score (APS) based on the Apache II classification, passage of gas, tolerance of enteral feeding, hospital stay and complications up to 30 days after surgery. The demographic data, magnitude of operation, duration of operation, intraoperative blood loss, and post-operative analgesic needs were similar in the groups. In all groups the APS was normal by median day 1 (range 1-7). A similar impairment of bowel function after operation, with passage of gas median 3 (1-6) days after surgery and tolerance of enteral intake median day 5 (1-10), was found in all groups. The incidence of complications and the length of postoperative hospital stay, median 11 (6-45) days, did not differ among the groups. It is concluded that overall recovery, bowel function, postoperative hospital stay, and complications were not influenced by the anaesthetic technique.
Department of Anaesthesiology, Faculty of Health Sciences, Linköping University Hospital, Sweden.
We have studied the influence of clinical concentrations of propofol (2,6-diisopropyl phenol), emulsified propofol (Diprivan) and the emulsifier of propofol (Intralipid 10%) on random and chemotactic locomotion of human polymorphonuclear leucocytes in an agarose assay. Random locomotion was decreased (P < 0.001) to a similar extent by the three drugs. Concentrations of propofol 2.5 micrograms ml-1 and greater, and of Diprivan 3.33 micrograms ml-1 and greater, also reduced chemotaxis (P < 0.05) against both zymosan-activated human serum (C5a) and N-formyl-methionyl-leucylphenylalanine (FMLP), used as chemoattractants. Intralipid reduced chemotaxis towards C5a but not towards FMLP. We conclude that propofol in clinically relevant concentrations may adversely affect leucocyte locomotion in vitro.
Propofol induces changes in the cytosolic free calcium concentration and the cytoskeletal organization of cultured human glial cells and primary embryonic rat brain cells.
BACKGROUND: The site of action of the intravenous anesthetic drug propofol is uncertain. Therefore, we examined the effects of propofol on the cytosolic free calcium levels of cultured primary embryonic rat brain cells (80-85% neurons), and on the organization of the cytoskeleton in these rat cells and in a model system of cultured human glial cells (astrocytes). METHODS: Propofol was added to the cells as the clinically available solution Diprivan. Cytosolic free calcium changes in neurons were studied using Fura2 and a single-cell microfluorometric method. Fluorescence microscopy was used to study the organization of actin filaments and tubulin in detergent-extracted cells. RESULTS: An increase in the cytosolic free calcium concentration of 116 +/- 39 nM was seen shortly after the addition of 0.3 microgram.ml-1 propofol, and a propofol concentration of 0.03 microgram.ml-1 resulted in an increase in cytosolic free calcium concentration of the same magnitude, 119 +/- 42 nM. Most of the calcium (60-75%) came from the extracellular environment, and the rest was from intracellular stores. When neurons were depleted of intracellular calcium by 1,2-bis-5-methyl-amino-phenoxylethane-N,N'-tetra-acetoxymethyla cetate (MAPT/AM), no changes were seen in the actin organization of the cytoskeleton. Actin organization was affected by all concentrations of propofol, 0.3-50 micrograms.ml-1 (1.7-280 microM), when exposure to the drug was achieved by a 30-min incubation. After the incubation, the exposed cells were more rounded and exhibited increased ruffling activity, both at the periphery and on the cellular surface, and ring-shaped actin structures were also seen. These effects were concentration dependent and reversible, and reached a maximum after 20 min of incubation. Propofol had no apparent effect on the organization of tubulin. CONCLUSIONS: Propofol induced changes in the cytoskeletal organization of actin in cultured rat neurons and human glial cells. These changes must have been due to the increase in intracellular calcium seen shortly after the addition of propofol, since no effects on actin organization were seen when intracellular calcium was depleted.
Ergonomics. 2011 Oct ;54 (10):953-60 21973006
Mechanical exposure among general practice dentists in Sweden and possible implications of rationalisation.
National Centre for Work and Rehabilitation, Department of Medical Health Sciences, Linko¨ping University, Linköping, Sweden. firstname.lastname@example.org
The present study investigates the dental work in terms of time distribution and mechanical exposure in value-adding work (VAW) and non-VAW. Further rationalisation of dental work would typically involve an increase in the proportion of VAW. Information on mechanical exposure within the classes of VAW and non-VAW may be used to predict possible implications of rationalisation. Sixteen dentists were investigated. Using a data logger, postures and movements were continuously recorded for each subject during the 4 h of work, which included the 45 min of video recording. Time distribution and mechanical exposure for the six different work activities identified were evaluated from the video recordings, using a loss analysis technique. VAW, which comprised 54% of the total working time, generally implied significantly more constrained mechanical exposures as compared with non-VAW. The results suggest that future rationalisation of dental work, involving a reduction of non-VAW, may increase the risk of developing musculoskeletal disorders. Statement of Relevance: The present study illustrates the potential effects of rationalisation on biomechanical exposures for dentists. The results highlight the significance of integrating ergonomic issues into the rationalisation process in dentistry in addition to ordinary workstation and tool design improvements performed by ergonomists.
Reduction in mortality after epidural anaesthesia and analgesia in patients undergoing rectal but not colonic cancer surgery: a retrospective analysis of data from 655 patients in central Sweden.
Department of Anaesthesiology and Intensive Care, University Hospital, Orebro, Sweden. email@example.com
BACKGROUND 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.
Division of Anaesthesiology, Department of Medical and Health Sciences, Linkoping University, Linkoping, Sweden.
Neuronal intracellular transport is performed by motor proteins, which deliver vesicles, organelles and proteins along cytoskeletal tracks inside the neuron. We have previously shown that the anesthetic propofol causes dose- and time-dependent, reversible retraction of neuronal neurites. We hypothesize that propofol alters the vesicular transport of cortical neurons due to this neurite retraction. Primary cultures of co-cultivated rat cortical neurons and glial cells were exposed to either 2 μM propofol, control medium or the lipid vehicle, in time-response experiments. Reversibility was tested by washing propofol off the cells. The role of the GABA(A) receptor (GABA(A)R) was assessed with the GABA(A)R antagonist gabazine. Vesicles were tracked using differential interference contrast video microscopy. Propofol caused a retrograde movement in 83.4±5.2%(mean±S.E.M.) of vesicles, which accelerated over the observed time course (0.025±0.012 μm.s⁻¹). In control medium, vesicles moved predominantly anterograde (84.6±11.1%) with lower velocity (0.011±0.004 μm.s⁻¹). Cells exposed to the lipid vehicle showed the same dynamic characteristics as cells in control medium. The propofol-induced effect on vesicle transport was reversible and blocked by the GABA(A)R antagonist gabazine in low concentration. Our results show that propofol causes a reversible, accelerating vesicle movement toward the neuronal cell body that is mediated via synaptic GABA(A)R. We have previously reported that propofol initiates neurite retraction, and we propose that propofol causes vesicle movement by retrograde flow of cytoplasm from the narrowed neurite.
Department of anaesthesiology and Intensive Care, Odense University Hospital, Odense, Denmark. firstname.lastname@example.org
Emergency patients need special considerations and the number and severity of complications from general anaesthesia can be higher than during scheduled procedures. Guidelines are therefore needed. The Clinical Practice Committee of the Scandinavian Society of Anaesthesiology and Intensive Care Medicine appointed a working group to develop guidelines based on literature searches to assess evidence, and a consensus meeting was held. Consensus opinion was used in the many topics where high-grade evidence was unavailable. The recommendations include the following: anaesthesia for emergency patients should be given by, or under very close supervision by, experienced anaesthesiologists. Problems with the airway and the circulation must be anticipated. The risk of aspiration must be judged for each patient. Pre-operative gastric emptying is rarely indicated. For pre-oxygenation, either tidal volume breathing for 3 min or eight deep breaths over 60 s and oxygen flow 10 l/min should be used. Pre-oxygenation in the obese patients should be performed in the head-up position. The use of cricoid pressure is not considered mandatory, but can be used on individual judgement. The hypnotic drug has a minor influence on intubation conditions, and should be chosen on other grounds. Ketamine should be considered in haemodynamically compromised patients. Opioids may be used to reduce the stress response following intubation. For optimal intubation conditions, succinylcholine 1-1.5 mg/kg is preferred. Outside the operation room, rapid sequence intubation is also considered the safest method. For all patients, precautions to avoid aspiration and other complications must also be considered at the end of anaesthesia.
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Department of Veterinary Clinical Sciences, Royal Veterinary College, Hatfield, Hertfordshire, UK. email@example.com
OBJECTIVE To assess the quality and length of recovery from anaesthesia induced with either propofol or alfaxalone and maintained with isoflurane, in cats undergoing short procedures in private veterinary practice. STUDY DESIGN Prospective, blinded, randomized study. ANIMALS Ninety-three healthy mixed breed cats. METHODS After premedication with intramuscular acepromazine (0.05 mg kg(-1)) and buprenorphine (0.01 mg kg(-1)), cats were randomly allocated to receive either propofol (Group P) or alfaxalone (Group A) for induction of anaesthesia. Following endotracheal intubation, anaesthesia was maintained with isoflurane vaporized in oxygen. The quality of induction, physiological parameters throughout anaesthesia and the duration of both surgery and anaesthesia were recorded. The level of ambient noise, recovery times, number of attempts to stand, reaction of the cat to touch 15 minutes after extubation, and other relevant characteristics of the recovery period were noted and a video recording of the recovery was made. The videos were assessed by a second, blinded anaesthetist, using simple descriptive and visual analogue scales. RESULTS No statistically significant differences between groups with respect to preoperative data, premedication, surgery, anaesthesia and recovery times and scores were observed. There was a statistically significant difference in the number of patients paddling and trembling on recovery in Group A (p = 0.032) even though there was no statistically significant difference in the level of ambient noise in the recovery ward or in the overall quality of recovery. CONCLUSIONS Both propofol and alfaxalone provide good recovery characteristics in premedicated cats undergoing short procedures in clinical settings. Alfaxalone induction was associated with more episodes of paddling and trembling during recovery. CLINICAL RELEVANCE Both agents would appear appropriate for induction of anaesthesia in cats for short procedures.
Department of Anaesthesiology & Intensive Care, Sahlgrenska University Hospital/East, Gothenburg, Sweden. firstname.lastname@example.org
The objective of this study was to evaluate whether major abdominal surgery leads to complement activation and interleukin response and whether the kind of anaesthesia influence complement activation and the release of inflammatory interleukins. The study design was prospective and randomised. Fifty patients undergoing open major colorectal surgery due to cancer disease or inflammatory bowel disease were studied. Twenty-five patients were given total intravenous anaesthesia (TIVA) with propofol and remifentanil, and 25 patients were given inhalational anaesthesia with sevoflurane and fentanyl. To determine complement activation (C3a and SC5b-9) and the release of pro- and anti-inflammatory interleukins (tumour necrosis factor-a (TNF-a)), interleukin-1b (IL-1b), IL-6, IL-8, IL-4 and IL-10), blood samples were drawn preoperatively, 60 minutes after start of surgery, 30 minutes after end of surgery and 24 hours postoperatively. Complement was activated and pro-inflammatory interleukins (IL-6 and IL-8) and anti-inflammatory interleukins (IL-10) were released during major colorectal surgery. There was no significant difference between TIVA and inhalational anaesthesia regarding complement activation and cytokine release. Major colorectal surgery leads to activation of the complement cascade and the release of both pro-inflammatory and anti-inflammatory cytokines. There are no significant differences between total intravenous anaesthesia (TIVA) with propofol and remifentanil and inhalational anaesthesia with sevoflurane and fentanyl regarding complement activation and the release of pro- and anti-inflammatory interleukins.
Evaluation of the quality of the recovery after administration of propofol or alfaxalone for induction of anaesthesia in dogs anaesthetized for magnetic resonance imaging.
Department of Veterinary Clinical Science, Royal Veterinary College, North Mymms, Hatfield, UK. email@example.com
OBJECTIVE To compare the quality of the recovery when propofol or alfaxalone were administered for the induction of anaesthesia in dogs undergoing neurological diagnostic procedures. EXPERIMENTAL DESIGN Prospective, randomized clinical trial. ANIMALS Forty two client-owned dogs, 21 females and 21 males, weighing between 5.7 and 55 kg. METHODS Each dog was sedated with methadone (0.2 mg kg(-1) intramuscularly or 0.1 mg kg(-1) intravenously). Sedation was scored after 30 minutes. Anaesthesia was induced either with propofol or alfaxalone, administered to enable orotracheal intubation, after which anaesthesia was maintained with sevoflurane in oxygen. At the end of the procedure, the animals recovered in the clinical area. Quality of recovery was scored (early recovery) using simple descriptive and visual analogue scales (SDS and VAS). When sternal recumbency was achieved, dogs were moved to the recovery room and recovery was scored again (late recovery). Quantitative data were assessed with the Mann-Whitney U test, Kruskal-Wallis test, Spearman's rank correlation and Bland Altman plots as appropriate, whilst categorical data were analysed with the Chi square test and weighted kappa. RESULTS Sex, behaviour and duration of anaesthesia did not influence recovery scores. Dogs had poorer late recovery scores in the alfaxalone group compared to the propofol group (SDS, p = 0.014; VAS, p = 0.017). Degree of sedation after premedication influenced assessed SDS scores during early (p = 0.038) and late recovery (p = 0.008)(dogs more heavily sedated recovered better). However by VAS scores, sedation did not statistically influence early recovery (p = 0.299) but did affect late recovery (p = 0.013). Rescue sedation (medetomidine) was required only in two dogs in the alfaxalone group. CONCLUSIONS Induction of anaesthesia with alfaxalone was associated with poorer recovery than with propofol in animals receiving premedication with methadone. CLINICAL RELEVANCE Greater attention to the recovery environment may be advisable when using alfaxalone for induction of anaesthesia where minimal premedication has been used. Further sedation in recovery may be required.
J Opioid Manag. ;5 (5):247-55 19947068
Comparison of the effect of adding remifentanil to patient-controlled tramadol or morphine for postoperative analgesia after major abdominal surgery.
Department of Anesthesiology, Cukurova University, Balcali, Turkey.
OBJECTIVE: In this study, the authors investigated the effect of the addition of remifentanil to tramadol or morphine for patient-controlled analgesia (PCA). DESIGN: Prospective, randomized, double-blind, controlled study. SETTING: University Hospital. PATIENTS, PARTICIPANTS: The authors randomly allocated 133 patients undergoing major abdominal surgery to receive IV PCA with tramadol alone, tramadol plus remifentanil, morphine alone or morphine plus remifentanil. INTERVENTIONS: Bolus doses of tramadol (0.2 mg/kg), tramadol (0.2 mg/kg) plus remifentanil (0.2 microg/kg), morphine (0.02 mg/kg), or morphine (0.02 mg/kg) plus remifentanil (0.2 microg/kg) were available every 10 minutes without time limit or background infusion. MAIN OUTCOME MEASURE(S): Discomfort, sedation, pain scores, side effects, and total and bolus tramadol and morphine consumption were recorded for up to 24 hours after the start of PCA. RESULTS: Pain scores at rest and movement were greater with tramadol alone than in the other groups at 1, 2, and 6 hours (p < 0.0125). The addition of remifentanil reduced cumulative tramadol consumption at 6, 12, and 24 hours, but not morphine consumption. More patients required supplementary rescue analgesia with meperidine, and with greater dosage, with tramadol alone (p < 0.001), and the incidence of nausea was greater with tramadol alone. The addition of remifentanil not only significantly improved discomfort scores in remifentanil groups, but also increased the degree of sedation in morphine-remifentanil group. CONCLUSIONS: After major abdominal surgery, adding remifentanil to PCA tramadol resulted in better pain scores, lower analgesic consumption, and fewer side effects when compared with tramadol alone. However, analgesic outcome with remifentanil was not prominent in MR group as much as in TR group.
Department of Anaesthesia, St Mary's Hospital, London W2 1NY, UK. firstname.lastname@example.org
BACKGROUND This study prospectively determined the haemodynamic changes in the lower limb venous circulation during and shortly after elective abdominal surgery, performed under general anaesthesia. METHODS Ten females, aged 36-65 yr, ASA I or II, undergoing total abdominal hysterectomy had their peak, mean and minimum velocities, diameter, volume flow and venous pulsatility (peak-minimum/mean velocity) measured in the left popliteal vein on recumbency with duplex at:(i) baseline,(ii) 15 min after induction,(iii) during surgery, and (iv) in recovery 30 min after extubation. Anaesthesia was induced with fentanyl and propofol, paralysis with vecuronium, maintenance with isoflurane in nitrous oxide 66%, and analgesia with morphine. Results are presented as percentage difference from baseline mean value. The Friedman and Wilcoxon([corrected(*)]) tests were applied. RESULTS Mean velocity decreased by 23.6% during surgery and by 34.6% in recovery (P<0.05(*)). Minimum velocity was decreased by 56% during surgery and by 78% in recovery (P<0.05). The volume flow decreased by 26% during surgery, and by 54.4% in recovery (P<0.001). Diameter and peak velocity changed little at surgery and recovery (P>0.2). In contrast, the pulsatility increased by 30% on induction, 83% on surgery and 109% in recovery (P<0.05). Compared with baseline, haemodynamic changes on induction were small (P>0.1(*)). CONCLUSIONS A significant decrease in the volume flow, mean and minimum velocities was noted during and immediately after elective total abdominal hysterectomy under general anaesthesia in ASA I and II patients. Flow changes in early recovery mirrored or enhanced those noted intraoperatively. Despite venous flow attenuation, haemodynamic readjustments produced a significant and progressive enhancement of venous flow pulsatility during the course of the procedure.
[Catabolic stress response during and after abdominal surgery. Comparison between two anaesthesia procedures]
Klinik für Anästhesiologie, Klinikum der Universität Regensburg.
BACKGROUND: The purpose of the study was to investigate the effect of modified neuroleptanesthesia (NLA) with fentanyl/midazolam on the catabolic responses during and after abdominal surgery. METHODS: A total of 13 patients undergoing cystoprostatectomy received either modified NLA ( n=7) or inhaled anesthesia with isoflurane (ISO, n=6). Glucose and urea production rates were assessed before, during and 1 day after the operation. Plasma concentrations of glucose, urea, lactate, insulin, glucagon and cortisol were also determined. RESULTS: In contrast to isoflurane anesthesia, modified NLA prevented an increase in plasma glucose concentration and glucose production during ( P<0.05), but not after surgery. There were no differences in perioperative urea production rates or plasma concentrations of urea, insulin, glucagon and lactate between the two groups. Modified NLA suppressed the intraoperative increase in plasma cortisol concentration as observed in the ISO group ( P<0.05). CONCLUSION: Modified NLA inhibits the increase in plasma glucose concentration and glucose production as seen during isoflurane anesthesia. However, NLA does not influence the catabolic response on the first postoperative day.
[Motor function during patient-controlled analgesia via a lumbar epidural catheter after major abdominal surgery. Ropivacaine-sufentanil vs. bupivacaine-sufentanil]
Universitätsklinik für Anästhesie und Intensivtherapie Philipps-Universität Marburg. email@example.com
INTRODUCTION: The aim of the present study was to investigate postoperative motoric impairment during patient-controlled analgesia after major abdominal surgery with ropivacaine-sufentanil and bupivacaine-sufentanil via a lumbar epidural catheter. METHODS: After approval of the local ethics committee, 40 patients scheduled for major lower abdominal surgery were randomly allocated to receive bupivacaine 0.25 % or ropivacaine 0.2 %, both with sufentanil 2 microgram/ml in a double blind manner. General anaesthesia (midazolam, etomidate, fentanyl, vecuronium, and desflurane in N2O/O2) and postoperative management of the patients were standardised. Postoperatively, the motoric function and ability for active early mobilisation was examined clinically (application of the Bromage scale, ability to leave the bed and ability to walk). Reduction of muscular force of the legs was measured postoperatively using a scale and compared with preoperative baseline values. To ensure a similar level of analgesia, a 10-cm visual analogue scale was applied at rest and while coughing. RESULTS: The two groups did not differ with respect to the demographic data and postoperative levels of analgesia. Less reduction of motoric function at rest was observed in the ropivacaine group (p = 0,044). However, this did not lead to an increased ability to get up from bed (p = 0,57) or to walk around (p = 0,17). A high number of patients did not meet the requirements for early ambulation. Almost half of the patients of both groups were unable to leave their beds in the morning of the first postoperative day. On the second postoperative day about 25 - 30 % of the patients could not walk even when support was applied. Furthermore, median reduction (10th/90th percentile) of muscular strength was reduced to 50 %(37 %/76 %) in the ropivacaine group and to 48 %(31 %/61 %) in the bupivacaine group compared with preoperative values. DISCUSSION: While quality of analgesia was similar, mobility of the legs at rest is better preserved with ropivacaine 0.2 % than with bupivacaine 0.25 %. However, despite the fact that high dose sufentanil was added to both local anaesthetics, there was marked motoric impairment in both groups probably due to the lumbar site of the epidural catheter. This was associated with an unacceptable high incidence of patients unsuitable for early postoperative mobilisation.
Patient-controlled pethidine after major upper abdominal surgery: comparison of the epidural and intravenous routes.
Department of Anaesthesia and Intensive Care, The Chinese University of Hong Kong, Prince of Wales Hospital, Shatin, Hong Kong SAR, China. firstname.lastname@example.org
We compared epidural (n = 17) and intravenous (n = 20) patient-controlled analgesia (PCA) using pethidine (bolus 10 mg, lockout interval 10 min, 4-h maximum dose 3 mg.kg(-1)) after total gastrectomy. We found that mean (SD) pethidine consumption in the first 24 h was 33% less in the epidural group [255 (85) mg] than in the intravenous group [379 (129) mg, p = 0.002], although most of this difference occurred in the first 8 h. Plasma concentrations of pethidine were lower at 8 h (p < 0.01) in the epidural group, but were similar at 24 h. Pain scores, side-effects, patient satisfaction and patient outcome were similar between groups. Epidural and intravenous pethidine PCA provided similar efficacy after major abdominal surgery, although the epidural route can reduce the amount of pethidine used initially.
Psychomotor recovery in very old patients after total intravenous or balanced anaesthesia for cataract surgery.
Department of Anesthesiology, University of Heidelberg, Germany.
We compared psychomotor recovery after total intravenous anaesthesia (TIVA) with remifentanil/propofol and balanced anaesthesia (BAL) with etomidate/fentanyl/isoflurane in 40 patients, ASA I-III, aged > or =80 yr undergoing elective cataract surgery. Recovery times were recorded and psychomotor recovery was assessed according to simple reaction time, critical flicker fusion frequency (CFF) and short-term memory 30 min, 2 h and 1 day after surgery. Physical characteristics of patients in the two groups (19 in the TIVA group and 21 in the BAL group) were comparable. The TIVA group recovered significantly more quickly. Both groups showed a poorer psychomotor performance 30 min after surgery than at baseline assessment, but simple reaction time and short-term memory were close to baseline values 2 h after surgery. Only performance in the CFF test remained below baseline at this point. No deficits in psychomotor performance were noted on the first day after surgery. We conclude that there is only a minor deficit in psychomotor function in elderly patients 2 h after cataract surgery under general anaesthesia and that psychomotor function recovers completely by 24 h after surgery.
Total intravenous versus inhalational anaesthesia for colonoscopy: a prospective study of clinical recovery and psychomotor function.
Department of Anaesthesia, Westmead Hospital, Sydney, New South Wales.
A randomized, prospective study was conducted on 69 patients comparing recovery after two different anaesthetic techniques for ambulatory colonoscopy. Thirty-five patients received an intravenous fentanyl (1 microg/kg), midazolam (0.05 to 0. 075 mg/kg) and propofol (10 to 20 mg boluses as required) combination. 34 patients received sevoflurane in 67% nitrous oxide. Drug administration was titrated to clinical signs. At baseline and 30, 60, 90 and 120 minutes after the procedure patient performance on a comprehensive battery of psychomotor tests was recorded. Emergence times were noted. Depth of sedation was assessed at 5 minute intervals for 30 minutes after the end of the procedure. Emergence times were faster in the fentanyl/midazolam/propofol group by 2.2 minutes. A lower sedation score was detected at 20 minutes in the sevoflurane/nitrous oxide group. Psychomotor impairment was of a greater magnitude and more prolonged by 30 to 90 minutes in the fentanyl/midazolam/propofol group. It is concluded that a sevoflurane/nitrous oxide anaesthetic has a suitable recovery profile for ambulatory colonoscopy and results in faster recovery of cognitive function compared with a fentanyl, midazolam and propofol combination.