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Biomedical subjects

E Alon

Publications and source records attributed to E Alon.

At least 19 recordsLinked to original sources

Post-operative epidural versus intravenous patient-controlled analgesia.

Patient-controlled analgesia techniques have opened a new dimension to individualize patient's need for analgesia, in the treatment of acute post-operative pain. These techniques can be used intravenously, in the epidural space, and into peripheral nerve sheets. There is a common consensus that intravenous patient-controlled analgesia should not have a continuous infusion while epidural patient-controlled analgesia (PCEA) should be programmed with a continuous infusion. The drugs used for epidural analgesia are: opioids, local anaesthetics or the combination of both. The combinations seem to provide better pain relief and less side effects. The continuous epidural infusion of opioids has the advantages of fewer fluctuations in cerebrospinal fluid concentrations of drug, but it is necessary to administer a loading bolus, to overcome the fact that it takes several hours to provide adequate analgesia. The advantages of epidural versus intravenous patient-controlled analgesia are represented by better analgesia and a reduced opioids requirement, while the advantages when compared to epidural continuous infusion are: increased efficiency, self-adjustment by the patient, higher patient satisfaction, less sedation, and lower opioids dosage. The clinical advantages of PCEA may outweigh the greater cost and invasiveness of this technique.

Analgesia, Epidural↗

[Operating room management].

The changing health care climate has triggered important changes in the management of high cost components of acute care facilities. By integrating and improving management of various elements of the surgical process, health care institutions are able to rationally trim costs while maintaining high-quality services. If the results of surgery are viewed as a product, everything associated with surgery can be evaluated as one would a manufacturing process. All steps involved in producing the end result can and should be analyzed with the goal of producing an efficient, economical and quality product. The leadership that physicians can provide is crucial to the success of this undertaking. The role of the anesthesiologist in the management of the operating room setting (OR) has gained broad acceptance because: a) it contributes to the effort of a larger team process; b) the anesthesiologist ordinarily practices in the OR setting; and c) the anesthesiologist can view the priorities of the OR in an unbiased manner. Many of the successful concepts in managing an OR are just common sense. The single best opportunity for dramatic improvement in effective resource use in Surgical Services lies in the perioperative process. The management strategy must focus on process-measurement using information technology and feedback implementing modern quality management tools. The impact of new treatments, drugs, devices and process changes can be assessed rationally.

Appointments and Schedules↗

[Opioids in treatment of chronic noncancer pain].

Opioids have been accepted as appropriate analgesic treatment for pain associated with cancer. However, controversy exists about their use for chronic noncancer pain. Reasons for reluctance are concerned about efficacy and potential adverse effects such as respiratory depression, addiction, physical dependence or intolerance. Many physicians worry about liability and legal restrictions. Nevertheless, pain management of chronic severe pain with opioids can be the only help when alternative methods are too risky of fail to be effective. This article briefly reviews the published literature on this topic and discusses some practical guidelines for the use of opioids in the treatment of non-cancer pain.

Analgesics, Opioid↗

Outcome of cardiovascular surgery and pregnancy: a systematic review of the period 1984-1996.

The outcomes of cardiovascular operations during pregnancy, at delivery, and post partum were reviewed from published material in the period 1984-1996. Surgery during pregnancy resulted in fetal-neonatal morbidity and mortality of 9% and 30%, respectively, and in maternal morbidity and mortality of 24% and 6%, respectively. Duration of pregnancy at surgery and duration and temperature of cardiopulmonary bypass did not influence fetal-neonatal outcome. Maternal complications and mortality of surgery immediately after delivery were 29% and 12%, respectively, and for surgery performed with a postpartum interval the respective rates were 38% and 14%. Hospitalization after week 27 of gestation and extreme emergency contributed significantly to poor maternal outcome. Maternal deaths were reported in 9% of valvular procedures and in 22% of aortic or arterial dissection repairs and pulmonary embolectomies. Fetal-neonatal risks of maternal surgery during pregnancy are high and unpredictable. Maternal risks of cardiovascular procedures during pregnancy are moderate, significantly increase if an operation is performed at or after delivery, and, overall, should be considered as higher than those in nonpregnant cardiovascular surgical patients.

Cardiopulmonary Bypass↗

Measurement of intraocular pressure during laparoscopy and its relationship to central venous pressure.

UNLABELLED: STUDY OBJECTIVE. To determine the effect of different positional degrees on hemodynamics, especially central venous pressure and intraocular pressure, and a possible interrelationship, during laparoscopic surgery. SETTING. University teaching hospital (Canadian Task Force classification II-1). PATIENTS: Seven women undergoing elective gynecologic laparoscopy. INTERVENTIONS: The women were monitored for heart rate, partial pressure of oxygen, end-tidal carbon dioxide, arterial blood pressure, central venous pressure, end-tidal isoflurane concentration, and intraocular pressure in several body positions during general anesthesia. MEASUREMENTS AND MAIN RESULTS: Intraocular pressure depends on body position (r2 = 0.58) related to central venous pressure (r2 = 0.7). Heart rate and arterial blood pressure are also dependent on the body position, but to a lesser degree. CONCLUSION: Continuous monitoring of intraocular pressure may help detect alterations in central venous pressure during general anesthesia for laparoscopic surgery. Undesirable alterations caused by degree of Trendelenburg position may negatively affect patients with high cardiac or ophthalmic risk.

Adult↗

Tropisetron for treating established postoperative nausea and vomiting: a randomized, double-blind, placebo-controlled study.

UNLABELLED: Tropisetron can prevent postoperative nausea and vomiting (PONV) at doses smaller than those used to control chemotherapy-induced nausea and vomiting. In this placebo-controlled study, the efficacy and tolerability of three different doses of tropisetron were compared for the treatment of established PONV after surgical procedures in general anesthesia. Of 1513 patients who satisfied inclusion criteria, 314 experiencing PONV during the first 2 h after recovery from anesthesia were treated with one of three different doses of tropisetron (0.5, 2, or 5 mg) or placebo, administered i.v. as a single dose. Patients were then observed during 24 h for efficacy and tolerability. All three doses of tropisetron were significantly better than placebo in controlling emetic episodes and in reducing the need for rescue treatment. There were no significant differences among the three doses. However, in the subgroup of patients who had previous PONV, and in those randomized for nausea alone, the 2-mg and 5-mg doses controlled emetic episodes better than the 0.5-mg dose. All studied doses of tropisetron were well tolerated and did not affect vital signs. We conclude that a single i.v. administration of tropiestron significantly reduces the recurrence of emetic episodes in patients with established PONV after elective surgery with general anesthesia. Its optimal dose seems to be 2 mg. IMPLICATIONS: Three hundred-fourteen patients suffering from postoperative nausea and vomiting received different i.v. doses of a new antiemetic drug, tropisetron, to determine the lowest effective dose. We found that a single i.v. administration of tropisetron significantly reduced postoperative nausea and vomiting after elective surgery with general anesthesia.

Abdomen↗

[The dose-dependent effects of oral premedication with midazolam].

OBJECTIVE: The aim of this study was to examine the psychological effects, well-being and side effects after various doses of oral midazolam medication. METHODS: After informed consent has been obtained and following the approval by the institutional ethical committee, 80 adult patients in the ASA physical status I and II were randomly assigned to one of five different premedication groups: 3.75, 7.5, 11.25, 15 mg midazolam, and placebo. The medication was given in a double-blind fashion 60 min before induction of general anaesthesia for various surgical procedures. At 3 definite stages (before premedication, 30 and 60 min after premedication), blood pressure, heart rate, transcutaneous oxygen saturation and respiratory rate were measured. Sedation and well-being were graded according to a 5-point scale, and the subjective anxiety level was assessed according a visual analogue scale (range 0-100 mm). Anterograde and retrograde amnesia were measured by recall of auditive and visual stimuli. Finally, patients were asked whether in case of future surgery they would prefer the same or a different medication. RESULTS: Demographic data were similar in all groups. There was no significant difference in respiratory rate, oxygen saturation, blood pressure or heart rate. Alertness declined only after 60 min in the groups treated with 7.5 mg and more midazolam. During the entire measurement period, anxiolysis was not different from placebo in any of the midazolam groups. In comparison to placebo, all midazolam groups showed a statistically significant and dose dependent anterograde amnesia for visual stimuli. Subjective well-being scores showed no differences between the groups. Only few side effects were seen following doses of 7.5 mg and higher, including ptosis, strabismus, diplopia, speech disorders, disorientation and vertigo. The majority of patients in all groups indicated a wish for the same medication in case of future anaesthesia for surgical interventions. CONCLUSIONS: Midazolam administered orally prior to surgical procedures showed marked interindividual variability. Sedation and amnesia were dose-dependent and were evaluated by the patients as acceptable. Anxiolysis was not significantly different from placebo. A dose of 7.5 mg midazolam showed the best relation between desirable and undesirable effects. Adequate attention given to the patient by the anaesthesiologist prior to surgery seems to be as important and beneficial as oral medication with midazolam.

Administration, Oral↗

[Prevention and treatment of postoperative nausea and vomiting with 5-HT3-receptor blockers].

Since there continues to be a high incidence of postoperative nausea and vomiting associated with many types of surgery, and the standard antiemetics often do not achieve satisfactory results, there have been attempts to use the 5-HT3 antagonists. This group of substances is relatively new, but has already been used successfully as an antiemetic during chemotherapy. To date, results are on hand for four different 5-HT3 receptor blockers: ondansetron, tropisetron, granisetron and dolasetron. Applied intravenously, all four have been effective both in prophylaxis and also as therapy for postoperative emesis. Except for ondansetron, there is so far no definitely clear knowledge about the lowest possible effective dosage. The entire group is well tolerated: only occasional and minor side effects have been reported. Even though not all the hopes originally set in the 5-HT3 group of antagonists have been fulfilled, progress has nevertheless been achieved. Especially noteworthy points are a positive cost-effectiveness relationship of these drugs and their appropriate use in case of the proper indications.

Antiemetics↗

Tropisetron for the prevention of postoperative nausea and vomiting in women undergoing gynecologic surgery.

The aim of this study was to evaluate the efficacy of tropisetron, a selective 5-hydroxytryptamine type 3 (5-HT3) receptor antagonist, versus placebo in the prevention of postoperative nausea and vomiting in patients undergoing general anesthesia for gynecologic surgery. Ten minutes before induction of general anesthesia, 80 patients received in a double-blind manner a single intravenous (IV) injection of either 5 mg tropisetron or a matching placebo. Anesthesia was induced with thiopental and maintained with nitrous oxide and enflurane in oxygen. In the first 24 h postoperatively 7 of 40 patients (17.5%) given tropisetron and 16 of 40 patients (40%) receiving placebo vomited (P < 0.05). The incidence of nausea was 30% (12/40) in the tropisetron group and 52% (21/40) in the placebo group (P < 0.05). A total effective antiemetic response showed 26 patients (65%) in the tropisetron group and 16 patients (40%) in the placebo group (P < 0.05). We conclude that tropisetron given IV prior to gynecologic procedures in general anesthesia significantly reduces postoperative nausea and vomiting when compared to placebo without causing any adverse effect.

Adolescent↗

[Gynecological management of patients over 80 years old. Results of a prospective study].

OBJECTIVE: Diagnosis and therapy of gynecologic inpatients who were over 80 years of age were analyzed with respect to the desired and the actual management. METHODS: A general assessment protocol for diagnostic and therapeutic steps which were not carried out in individual cases was drawn up and used for the 96 patients analyzed. The desired therapy corresponded to the ideal management of a 60-year-old patient. RESULTS: In two thirds of the cases, the desired therapy could be given. For 32 patients, there was a reduction of 5-50%; for only 2 patients one of > 50%. The most frequent deviation from the ideal therapy was for the oncologic patients. CONCLUSIONS: Our conclusions agree with those reported in the literature, namely that age alone can not be taken as an argument against standard treatment of a patient with a gynecologic disorder. For patients over 80 years of age, the individual risks and benefits of a particular therapy, especially when surgery is involved, should be carefully considered.

Aged↗

Effects of single-dose oral ranitidine and sodium citrate on gastric pH during and after general anaesthesia.

The effects on gastric pH of the H2-receptor antagonist ranitidine (R) with 0.3 molar (M) sodium citrate (SC) as an oral effervescent and those of plain SC were studied in 25 patients scheduled for elective surgery. Following induction of general anaesthesia, the gastric contents were evacuated via a nasogastric tube, and a pH electrode was placed in the stomach. Then, eight patients received R 300 mg plus SC dose (Group R300), ten received R 150 mg plus SC dose (Group R150), and seven received 50 ml SC alone (Group SC). The drugs were administered orally in a double-blind fashion, and the gastric pH was recorded continuously over a period of 24 hr. Mean (range) baseline pH values were 1.2 (0.8-1.8), 1.3 (1.0-1.8), and 1.2 (0.9-1.6) in the R300, R150, and SC groups, respectively (P = NS among groups). These values increased to 7.0 (6.2-7.5), 6.9 (6.3-7.3), and 4.9 (1.9-7.3), respectively, at emergence from anaesthesia (P < 0.05 for R300 vs SC and R150 vs SC). Two minutes after administration of R300 and R150, a mean (range) gastric pH of 6.8 (5.8-7.5), and 5.6 (1.2-7.0), respectively, was reached, and remained above 2.5 for 14 hr (P = NS). Plain SC increased the gastric pH within two minutes to a mean of 6.8 (6.7-7.0), and maintained it above 2.5 for six hours (P < 0.05 for R300 vs SC at 8, 10, 12, and 14 hr after induction).(ABSTRACT TRUNCATED AT 250 WORDS)

Administration, Oral↗

[Intravenous anesthesia with propofol versus thiopental-/enflurane anesthesia. A consumption and cost analysis].

It may be possible to reduce costs in anaesthesia when there is a choice of drugs and methods. Two of the most widespread techniques are inhalation anaesthesia with enflurane following induction with thiopentone, and intravenous anaesthesia (IVA) with propofol. The aims of our study were to compare the costs, effectiveness and side effects of the anaesthetics involved in these two techniques, and to measure significant clinical parameters. METHODS. After approval by the hospital ethics committee, 40 adult patients of ASA physical status 1 and 2 who had been scheduled for elective septorhinoplasty and had given informed consent were entered in our prospective, single-blind randomized study. In 20 patients anaesthesia was induced with thiopentone (4-5 mg/kg) and suxamethonium (1-1.5 mg/kg) and maintained with enflurane. The other 20 patients received an initial i.v. bolus of propofol (2-2.5 mg/kg) followed by a propofol infusion adjusted to their individual clinical needs. Ventilation was performed in both groups with 70% nitrous oxide in oxygen, using a nonrebreathing system. Muscle relaxation was maintained with atracurium. The amounts of anaesthetics, oxygen, nitrous oxide, and muscle relaxants used were measured and a record of the costs was kept. In addition, circulatory and respiratory parameters and quantitative and qualitative aspects of recovery from anaesthesia were recorded. RESULTS. The biometric and clinical data did not differ significantly between the two groups. For induction, 382 (+/- 55.9) mg thiopentone costing 1.24 Swiss francs (SFr), or 172 (+/- 25.1) mg propofol costing 11.87 (SFr) was used. For maintenance, 28.3 (+/- 6.4) ml enflurane costing 21.96 SFr/h, or 450.7 (+/- 247) mg propofol costing 29.75 SFr/h was required. The need for muscle relaxants, oxygen, and nitrous oxide was also not significantly different in the two groups. Additional expenses were due to relaxation antagonists (1.91 SFr per patient in both groups) and to the perfusion pump system (8.60 SFr per patient in the IVA group only). Circulatory and respiratory parameters remained normal in both groups. In the propofol group, the heart rate tended to increase more at the beginning of anaesthesia, whereas later on it showed a tendency to lower values than in the thiopentone/enflurane group. Patients receiving IVA generally had a shorter awakening period, a higher degree of wellbeing during recovery, and needed less systemic analgesics (P < 0.05). CONCLUSIONS. Costs of anaesthetic drugs in the IV group totalled 54.50 SFr during the first hour, i.e. 1.65 times the costs in the thiopentone/enflurane group for the same time. However, with continuing duration of anaesthesia this ratio declines to 1.43 in anaesthesia lasting 2 h. In addition, IVA patients had a noticeably faster and far more pleasant recovery. Minute ventilation, oxygen consumption, heart rate and CO2 production indicated a less pronounced stress response and sympathetic activity during and after propofol. Quicker recovery of cognitive and psychomotor abilities, less postoperative pain and less impairment of respiratory function after IVA may lead to an earlier release from the postoperative recovery unit. This might be a cost-reducing factor that should be taken into account when these two anaesthetic regimens are concerned.

Adolescent↗

The time course of gastric pH changes induced by omeprazole and ranitidine: a 24-hour dose-response study.

The time-course of the effects of single-dose acid-reducing therapy in surgical patients is not known. Therefore, a prospective, randomized trial compared the effects of single-dose administration of omeprazole or ranitidine on gastric pH in 52 patients undergoing lower abdominal surgery. The two drugs were administered intravenously in random fashion after placement of a gastric electrode for continuous 24-h pH monitoring In patients receiving omeprazole 20 mg (n = 13) and 40 mg (n = 13), gastric pH > or = 2.5 was achieved after a median of 80 (range 15-269) min and 40 (6-102) min (P = not significant [NS]), whereas in those receiving ranitidine 25 mg (n = 13) and 50 mg (n = 13), this pH was reached after a median of 32 (15-82) and 44 (16-84) min, respectively (P = NS). Over the first 24 h postoperatively, gastric pH remained less than 2.5 for a significantly longer time (1060 min vs 611 min), and more than 4.0 for a significantly shorter time (240 min vs 780 min) after omeprazole 20 mg than after ranitidine 50 mg. There were no other significant differences among treatment groups regarding the duration of gastric pH less than 2.5, between 2.5 and 4.0, and more than 4.0. In all treatment groups, the gastric pH returned to the baseline value of < 2.0 within 18 h. We conclude that when it is desired that gastric pH be more than 4.0 for at least 3 h, a single dose of ranitidine 25 mg or 50 mg should be administered 30-45 min prior to induction of anesthesia.

Abdomen↗