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PubMed1998

Lack of neurohumoral response to pneumoperitoneum for laparoscopic cholecystectomy.

BACKGROUND: Pneumoperitoneum (PP) for laparoscopic surgery induces prompt changes in circulatory parameters. The rapid onset of these changes suggests a reflex origin, and the present study was undertaken to evaluate whether release of vasopressor substances could be responsible for these alterations. The influence of two different anesthesia techniques was also evaluated. METHODS: American Society of Anesthesiologists (ASA) class I patients, scheduled for laparoscopic cholecystectomy, were investigated. The first group (n = 10) was anesthetized intravenously. The second group (n = 6) had inhalation anesthesia. Plasma vasopressin, catecholamines, and plasma renin activity were investigated as neurohumoral vasopressor markers of circulatory stress. The general stress response to surgery was assessed by analysis of plasma cortisol. RESULTS: Induction of pneumoperitoneum caused no apparent activation of vasopressor substances, although several hemodynamic parameters responded promptly. CONCLUSION: The hemodynamic alterations, seen at the establishment of PP during stable anesthesia, cannot be explained by elevation of vasopressor substances in circulating blood.

Adolescent↗
PubMed1998

Influence of isoflurane anesthesia on motor evoked potentials elicited by transcortical, brainstem, and spinal root stimulation.

Electrical stimulation over the motor cortex, base of the skull, and cervical spine motor roots was performed in 9 male rats (410 +/- 86 g) before and after induction with isoflurane at 1 MAC concentration. The mean latency and amplitude of descending spinal evoked potential (DSEP) from spinal cord and motor evoked potentials (MEPs) from forearm muscles obtained after motor cortex, brainstem, and cervical root stimulations were calculated and compared. The electrical current intensity to elicit the MEPs after cortical, brainstem, and spinal roots stimulation were 23.4 +/- 7.6, 7.0 +/- 3.1, and 1.4 +/- 0.8 mA, respectively. The brainstem stimulation activated descending motor pathways with a latency midway between that produced by electrical stimulation over the motor cortex, and by electrical stimulation over the cervical enlargements. The latency difference between cortical (8.8 +/- 3.2 msec) and brainstem (5.7 +/- 1.2 msec) stimulation was 3.1 +/- 2.3 msec in all forearm extensor muscles. The latency difference between cervical (3.6 +/- 0.9 msec) and brainstem stimulation (5.7 +/- 1.2 msec) was 2.3 +/- 1.1 msec for the same muscles, suggesting the brainstem stimulation activates the descending motor neurons at the level of cervical-medullary junction. The amplitudes were 189 +/- 141, 672 +/- 354, and 765 +/- 389 microV for cortical, brainstem, and cervical root stimulations. The inhalation anesthesia isoflurane at 1 MAC (1.2%) completely abolished the cortical and brainstem MEPs within minutes, while the MEPs elicited by direct stimulation of the cervical spinal roots remained unchanged. Our results indicate synaptic-dependent MEPs elicited at motor cortex or brainstem levels are highly sensitive to isoflurane anesthesia.

Action Potentials↗
PubMed1999

Efficacy of repeat intravenous dosing of ondansetron in controlling postoperative nausea and vomiting: a randomized, double-blind, placebo-controlled multicenter trial.

STUDY OBJECTIVES: To compare repeat intravenous (i.v.) dosing of ondansetron 4 mg with placebo for the treatment of postoperative nausea and vomiting (PONV) in patients for whom prophylactic, preoperative ondansetron 4 mg i.v. was inadequate DESIGN: Randomized, double-blind, placebo-controlled study. SETTING: Ten outpatient surgical centers in the United States. PATIENTS: 2,199 male and female ASA physical status I, II, and III patients > or = 12 years old scheduled to undergo outpatient surgical procedures and receive nitrous oxide-based general anesthesia. INTERVENTIONS: Ondansetron 4 mg i.v. was administered to all patients before induction of general anesthesia. Patients who experienced PONV or requested antiemetic therapy within 2 hours after discontinuation of inhaled anesthesia were randomized (1:1) to either a repeat i.v. ondansetron 4 mg dose or placebo. MEASUREMENTS AND MAIN RESULTS: Of the 2,199 patients prophylactically treated with ondansetron 4 mg before anesthesia induction, 1,771 (80.5%) did not experience PONV or request antiemetic therapy during the 2 hours following discontinuation of anesthesia. Of the 428 patients who experienced PONV or requested antiemetic therapy during the same period, and were randomized to additional treatment (214 randomized to ondansetron, 214 randomized to placebo), the incidence of complete response (no emesis, no rescue medication, no study withdrawal) was similar for both ondansetron-randomized and placebo-randomized groups for the 2-hour (34% and 43%, respectively, p = 0.074) and 24-hour (28% and 32%, respectively, p = 0.342) postrandomization study periods. Repeat ondansetron dosing was not more effective than placebo in controlling either postoperative emesis or the severity/duration of postoperative nausea. The administration of an additional dose of ondansetron 4 mg postoperatively did not result in an increased incidence of adverse effects. CONCLUSIONS: In patients for whom preoperative prophylaxis with ondansetron 4 mg i.v. is not successful, a repeat dose of ondansetron 4 mg i.v. in the postanesthesia care unit does not appear to offer additional control of PONV.

Adolescent↗
PubMedDate not supplied

RO 21-3981 for intravenous surgical premedication and induction of anesthesia.

RO 21-3981, a new water soluble benzodiazepine, was studied in 24 patients both as an intravenous premedicant and to induce anesthesia. The premedicant dose of 5 mg produced lack of recall and marked sedation within 1 to 2 minutes after injection and persisted for at least 32 minutes. Subsequent induction of anesthesia required an additional 5 to 25 mg of RO 21-3981. However, anesthesia was not induced in 1 patient with 25 mg and was accomplished only with inhalation anesthesia. Loss of lid reflex was unreliable as a sign of induction for patients in whom tracheal intubation was planned. Although decreases in blood pressure of 10 to 30 mm Hg were noted after administration of RO 21-3981, systolic pressure was not recorded below 90 mm Hg. RO 21-3981, because of its amnesic, sedative, and anxiolytic properties, appears to be an excellent premedicant although the 5 mg dose studied was probably larger than necessary. For induction of anesthesia, RO 21-3981 may be an effective alternative to thiopental.

Adult↗
PubMed2006

Seizure length with sevoflurane and thiopental for induction of general anesthesia in electroconvulsive therapy: a randomized double-blind trial.

In general, seizure length does not correlate with clinical outcome with electroconvulsive therapy (ECT), but whether markedly short seizures are still therapeutic is unknown. Furthermore, seizure length effects on clinical outcome in ECT may be different among the various anesthetic agents available. Several studies have investigated the use of inhalational anesthesia in ECT with sevoflurane. In general, seizure length when reported has been in the range of typical values encountered in practice. We recently completed a randomized double blind trial with sevoflurane induction compared with thiopental. Seizure duration with sevoflurane anesthesia was 8 seconds shorter than with thiopental for electroencephalogram and 6.4 seconds shorter for motor, the latter just barely missing statistical significance. Absolute values for seizure duration with both sevoflurane and thiopental are well within typical ranges for those seen with the more commonly used methohexital as anesthetic.

Anesthesia, General↗
PubMed2002

Apoptotic lymphocytes induced by surgical trauma in dogs.

PURPOSE: An investigation was made of the population and function of lymphocytes in canine peripheral blood, in animals with or without laparotomy under inhalation anesthesia. METHODS: Fourteen healthy beagles were allocated to two experimental groups: laparotomy (group A) and without laparotomy (group B). Induction of anesthesia in both groups was carried out with an intravenous injection of thiopentone, and was maintained by isoflurane inhalation. Ten blood samples, consisting of 10 ml of venous blood withdrawn by venipuncture into syringes containing 200 units of preservative-free heparin, were taken, from before anesthesia to the 28th postoperative day. The blood samples were collected, and the number of lymphocytes, the lymphocyte subpopulations, the proportion of apoptotic lymphocytes, and plasma cortisol level were measured, and the blastoid transformation of lymphocytes was observed. RESULTS: Lymphopenia was observed in both groups after anesthesia. Flow cytometry indicated a greater reduction in the proportion of T lymphocytes than of B lymphocytes. Blast transformation was also depressed in both groups. Progression of apoptosis after anesthesia was demonstrated in both groups, with a higher percentage of apoptotic cells being observed in group A at 12 h after anesthesia (28.5 +/- 3.2% by TUNEL assay). Plasma levels of cortisol were elevated to a greater extent in group A at the end of anesthesia (10.3 +/- 0.8 microg/dl) than in group B (7.8 +/- 1.9 microg/dl). CONCLUSIONS: These results indicate that surgical trauma concomitant with anesthesia could impair immunocompetence by reducing the number and function of lymphocytes.

Journal Article↗
PubMed2003

Adult strabismus surgery under propofol sedation with local versus general anesthesia.

PURPOSE: To compare operating room and hospital discharge times between adult strabismus surgeries using intravenous propofol sedation with local anesthesia versus those using general anesthesia. METHODS: Thirty adult patients underwent uncomplicated strabismus procedures performed by one surgeon using propofol sedation and local subtenon's anesthesia. These were retrospectively matched with adult patients undergoing similar procedures by another surgeon using general inhalational anesthesia. Only one muscle had undergone previous surgery, and no adjustable sutures were used. Times from incision closure to leaving the operating room (Out OR time), and to hospital discharge (DC time) are compared. RESULTS: Propofol/local Out OR times ranged 2 to 8 minutes (mean, 4.8). General anesthesia Out OR times ranged from 3 to 28 minutes (mean, 8.8) (means differ at P<.001). At 10 minutes, 100% of propofol patients left the OR, but only 63% of general patients had done so (P<.001). Propofol/local DC times ranged from 30 to 140 minutes (mean, 64.8). General DC times ranged from 68 to 325 minutes (mean 116.5) (means differ at P<.001). At 60 minutes after completion of surgery, 53% of propofol/local patients had left the hospital, whereas none of general patients had left (P<.001). At 2.5 hours after surgery, 100% of propofol/local patients had left the hospital, but 10% of general patients remained, with two staying more than 5 hours. CONCLUSIONS: Many adult strabismus surgeries may be performed more efficiently with intravenous propofol sedation and local subtenon's anesthesia than with general anesthesia. Times from the end of surgery to leaving both the OR and the hospital are decreased compared with those of general anesthesia. Extreme delays are rare with propofol/local, but they occurred with general anesthesia.

Adult↗
PubMed1993

Principles and techniques of anesthesia and analgesia for exotic practice.

Principles and techniques of anesthesia and analgesia for small animal exotic practice are described. The use of regimens based around inhalation anesthesia are recommended over injectable anesthetics. Techniques of perianesthetic monitoring and support are described and emphasized. The article concludes with a discussion of anesthesia for specific exotic animals likely to be encountered in small animal practice.

Analgesia↗
PubMed1994

Anesthesia and sedation for late-term mares.

Heavily pregnant mares requiring anesthesia present special problems and challenges. The use of short-acting anesthetic agents, combined with inhalational anesthesia, mechanical ventilation, and blood pressure support, will ensure an optimal outcome by maintaining both maternal and fetal homeostasis. The provision of oxygen during recovery to the still gravid mare also is important for fetal survival.

Anesthesia↗
PubMed1997

[Room air contamination with halothane during pediatric bronchoscopy].

Halothane anesthesia is frequently used for pediatric bronchoscopy. A disadvantage of the equipment used, a rigid bronchoscope together with inhalation anesthesia is the contamination of the working environment. The aim of this study was to determine the exposure of anesthetist and endoscopist during pediatric bronchoscopy under halothane anesthesia in a worst-case working environment and to compare these measurements with the currently valid international threshold values. Ten children (ASA I-III) scheduled for diagnostic bronchoscopy were included in the study. After induction with thiopentone and relaxation with atracurium all children were intubated with a rigid bronchoscope and manually ventilated through a bypass of the bronchoscope. Anesthesia was maintained by means halothane (0.5-2.0 vol%) in 100% oxygen with a flow of 10 l/min. The investigation was done in an operating room without air conditioning and scavenging system. Trace concentrations were measured every 2 minutes in the breathing zones of the anesthetist and the endoscopist by means of a highly sensitive direct reading instrument. Lower detection limit was 0.02 ppm. The mean age (+/- SD) of the children was 29.9 +/- 15.9 months (range: 4 weeks-48 months). Ventilation and oxygenation were stable throughout the bronchoscopic procedure. Mean exposure (+/- SEM) to halothane was 57.7 +/- 18.9 ppm for the anesthetist and 96.3 +/- 22.9 ppm for the endoscopist. The difference was statistically significant (ANOVA, P < 0.05). All international threshold values (2-50 ppm) were exceeded by far. Peak concentrations higher than 200 ppm halothane could be detected several times. The main result of the present study is that under the given situation in the operating room with insufficient room ventilation and no scavenging system halothane anesthesia for rigid bronchoscopy in children results in an occupational exposure that is higher than all known health regulation guidelines. Therefore, in case of insufficient working conditions total intravenous anesthesia might be a better alternative also in very small infants.

Air Pollutants, Occupational↗
PubMed2001

Cardiopulmonary effects of prolonged anesthesia via propofol-medetomidine infusion in ponies.

OBJECTIVE: To determine cardiopulmonary effects of total IV anesthesia with propofol and medetomidine in ponies and effect of atipamezole on recovery. ANIMALS: 10 ponies. PROCEDURE: After sedation was induced by IV administration of medetomidine (7 microg/kg of body weight), anesthesia was induced by IV administration of propofol 12 mg/kg) and maintained for 4 hours with infusions of medetomidine (3.5 microg/kg per hour) and propofol 10.07 to 0.11 mg/kg per minute). Spontaneous respiration was supplemented with oxygen. Cardiopulmonary measurements and blood concentrations of propofol were determined during anesthesia. Five ponies received atipamezole (60 microg/kg) during recovery. RESULTS: During anesthesia, mean cardiac index and heart rate increased significantly until 150 minutes, then decreased until cessation of anesthesia. Mean arterial pressure and systemic vascular resistance index increased significantly between 150 minutes and 4 hours. In 4 ponies, PaO2 decreased to < 60 mm Hg. Mean blood propofol concentrations from 20 minutes after induction onwards ranged from 2.3 to 3.5 microg/ml. Recoveries were without complications and were complete within 28 minutes with atipamezole administration and 39 minutes without atipamezole administration. CONCLUSIONS AND CLINICAL RELEVANCE: During total IV anesthesia of long duration with medetomidine-propofol, cardiovascular function is comparable to or better than under inhalation anesthesia. This technique may prove suitable in equids in which prompt recovery is essential; however, in some animals severe hypoxia may develop and oxygen supplementation may be necessary.

Adrenergic alpha-Antagonists↗
PubMed2000

[The summarization of clinical experience of difficult tracheal intubation].

OBJECTIVE: To summarize our experiences and lessons of difficult tracheal intubation for clinical anesthesia reference. METHODS: We had done a retrospective analysis of clinical data on difficult tracheal intubation in 2,825 patients undergoing elective plastic surgery with anesthesia. The main causes of difficult tracheal intubation were the limitations of neck extension (n = 1,169), mouth opening (n = 889), both neck extension and mouth opening (n = 698), and micromaxillary deformity (n = 69). By the Cormack's classification, all the patients had the laryngeal exposure of grade II or more. The tracheal intubations were done under neuroleptanalgesia combined with topical spray of local anesthetic in 439 patients, intravenous anesthesia of sedative drugs and nondepolarizing relaxants of subnormal doses in 629 subjects, and total intravenous or inhaled anesthesia in 1,757 cases, respectively. RESULTS: The difficult tracheal intubations were completed using blind nasal intubations in 142 patients, blind oral intubations with direct laryngoscope in 2,377 patients, oral intubations with fiberoptic stylet rigid laryngoscope in 186 patients, and oral or nasal intubations with flexible fiberoptic bronchoscope in 72 patients. The incidence of successful intubation was 99.7%. The common complication of intubation was airway trauma and its incidence was 19.3% in all the patients. Anesthetic techniques could affect significantly the intubation time and the incidences of complications in the patients with difficult intubation. CONCLUSIONS: By the improvement of anesthetic methods and common intubation techniques, the intubation time and the incidence of complications in the patients with difficult intubations were reduced.

Adolescent↗
PubMed1998

[Anesthesia for tracheobronchial stent insertion].

We experienced nine cases of general anesthesia for tracheobronchial stent insertion. As far as possible, we anesthetized the patients under spontaneous respiration with inhalation anesthesia, depending on the types of the tracheobronchial stent (Dumon stent or expandable metallic stent), or respiratory status of the patient. Having experienced a case requiring PCPS (percutaneous cardiopulmonary support) to recover from severe ventilatory insufficiency due to tracheal perforation, we, in advance, inserted 18- or 20-gage cannulas into the femoral artery and vein for PCPS standby, and could manage general anesthesia safely for tracheobronchial stent insertion.

Adult↗
PubMedDate not supplied

[Explicit and implicit memory during inhalation and intravenous anesthesia].

OBJECTIVE: Patients rarely report memory or knowledge of surgery after general anesthesia. During apparently adequate surgical anesthesia, however, information processing of high level functions, such as language comprehension and learning, can continue unconsciously. Our objective is to assess whether different anesthetic techniques (two inhalational and two intravenous) guarantee the absence of both types of memory. PATIENTS AND METHOD: One hundred patients were randomly assigned to receive the following anesthetic procedures: desflurane/N2O (group 1), isoflurane/N2O (group 2), fentanyl/N2O (group 3) and total intravenous anesthesia (group 4). A cassette with the same music was played in all cases, and an order requiring a nonverbal response was given to 15 randomly chosen patients in each group. Response was evaluated at a visit 24 to 48 hours after surgery. Fifteen patients, therefore, constituted the study group for each anesthetic procedure, and 10 patients formed the control group. We assessed the presence of explicit memory in a structured interview, and implicit memory by way of the relation between the number of times the nonverbal order was obeyed and the time of the interview. RESULTS: Explicit memory was absent in all patients. The presence of implicit memory was confirmed, however, in the isoflurane (p = 0.02) group. Significant differences between the isoflurane group and both the desflurane and total intravenous anesthesia groups (p = 0.03) were found. CONCLUSION: Explicit memory was absent with all four anesthetic techniques used in our study. Implicit memory was more difficult to inhibit, however, with isoflurane/N2O.

Adolescent↗
PubMed2004

Middle ear pressure changes after nitrous oxide anesthesia and its effect on postoperative nausea and vomiting.

OBJECTIVES/HYPOTHESIS: This study was designed to explore the relationship between changes in middle ear pressure associated with inhalational anesthesia and the incidence of postoperative nausea and vomiting (PONV). STUDY DESIGN: Prospective, randomized. METHODS: Middle ear compartment pressures were measured by tympanometry in 27 randomly assigned knee arthroscopy patients throughout the surgical procedure as well as into recovery. RESULTS: A positive correlation between the maximum positive pressure (MPP) and maximum negative pressure (MNP) gradient and PONV was demonstrated (P <.05). The incidence of PONV in the nitrous oxide (N2O) treatment group was 6 of 16 patients, whereas only 2 of 11 patients in the control group developed nausea, vomiting, and vertigo symptoms. Those patients that did not experience PONV demonstrated a median MPP of 155 with a median MNP of -52. The patients that experienced PONV exhibited a median MPP of 179 with a median MNP of -164. This demonstrates a significant increase in the incidence of PONV in the N2O treatment group. CONCLUSIONS: Barometric changes in the middle ear contribute to the incidence of PONV induced by N2O.

Acoustic Impedance Tests↗
PubMedDate not supplied

[The first experience in using sevoflurane].

The paper analyzes the first experience in using the halogen-containing anesthetic sevoflurane, which is new for Russia, as an agent for initial narcosis and anesthesia maintenance in adult patients. For induction, delivery of sevoflurane was initiated in a dose of 0.7 r.% through the mask of an anesthetic-respiratory apparatus. After 3-5 breaths, the dose of sevoflurane was increased up to 2 r.%. The time of inhalation to the level of INEEG being achieved 40-45% was 3.2 +/- 0.5 min, while that with propofol was 3.3 +/- 1.0 min. Initial inhalational anesthesia was smooth, which did not exclude a slight short-term motor activity in 2 patients. Sevofluorane has a pronounced hypnotic, but a weak analgesic effect in adults, which requires the co-administration of fentanyl. Sevofluorane will be mostly demanded for initial narcosis and anesthesia maintenance in children and for the induction and maintenance of anesthesia in ambulatory anesthesiology and thriving one-day hospitals. The foregoing does not rule out the use of servofluorane for the induction and maintenance of anesthesia in adults.

Adult↗
PubMed1999

[Changes in lipoprotein (a) and the relation between lipoprotein (a) and endothelin in patients during upper abdominal surgery].

OBJECTIVE: We observed the changes in both serum lipoprotein(a) [Lp(a)] and plasma endothelin (ET) during upper abdominal surgery under intravenous combined with inhalation anesthesia and we also analyzed their correlativity. METHODS: Fifteen patients, scheduled for upper abdominal surgery, were anesthetized with total does of fentanal 8-12 micrograms.kg-1 and inhalation of 1-2 MAC enflurane. Serum Lp(a) and plasma ET at pre-anesthesia, pre-operation, 1 h from the start of operation and 30 min after operation were determined. RESULTS: The average concentrations of Lp(a) and ET were increased at 1 h from the start of operation compared with pre-anesthesia, but had no statistical significance. Lp(a) and ET were significantly higher at 30 min after operation than pre-anesthesia(P < 0.05). CONCLUSION: Lp(a) and ET have a close relation in advancing cardio-cerebral blood vessel diseases.

Abdomen↗