Isoflurane For Maintenance Of Anesthesia Research Articles

A randomised controlled trial comparing quality of recovery between desflurane and isoflurane inhalation anaesthesia in patients undergoing ophthalmological surgery at a tertiary hospital in South Africa (DIQoR trial)

BackgroundThe patient's experience of their postoperative recovery is an important perioperative outcome, with the 15-item quality of recovery scale (QoR-15) recommended as a standardised outcomes measure. Desflurane has a faster emergence from anaesthesia compared with other volatile anaesthetics, but it is uncertain whether this translates to better subjective quality of recovery. The hypothesis for this study is that patients receiving desflurane for maintenance of anaesthesia would have better postoperative quality of recovery than patients receiving isoflurane. MethodsMale and female adult patients undergoing ophthalmological surgery under general anaesthesia were randomly allocated to receive desflurane or isoflurane for maintenance of anaesthesia. The primary outcome was to compare postoperative QoR-15 scores. Secondary outcomes included comparing preoperative QoR-15 scores, volatile agent consumption, and time spent in the recovery room. ResultsData from 164 patients were analysed (80 desflurane, 84 isoflurane). Median (Q1, Q3) postoperative QoR-15 scores were not significantly different (desflurane: 145 [141, 148], isoflurane: 144 [139, 147], 95% confidence interval 0–3, P=0.176, minimal clinically important difference=8). Median (Q1, Q3) volatile agent consumption was 15.4 (12.5, 19.3) ml hr−1 in the desflurane group, and 7.4 (5.9, 9.7) ml hr−1 in the isoflurane group. Median (Q1, Q3) time spent in the recovery room was significantly shorter in the desflurane group (desflurane: 18 [13, 23]; isoflurane: 25 [19, 32], 95% confidence interval −10 to 5, P<0.001). ConclusionsThis study found no difference in quality of recovery between patients who received desflurane or isoflurane for maintenance of general anaesthesia during ophthalmological surgery. A shorter time in the recovery room was not associated with improved QoR-15 scores. Clinical trial registrationNCT04188314.

Uncommon concern during MRI of conjoined twins under general anesthesia.

Dear Editor, Anesthesia management for magnetic resonance imaging (MRI) of conjoined twins poses challenges to deal with two infants simultaneously, unfamiliar environment, limited space and personnel.[1] Providing anesthesia for MRI to conjoined twins is a rare opportunity that requires two MRI compatible anesthesia workstations. We report a peculiar problem due to different terminal wall-mount outlets in MRI complex. Six-month-old pyopagus conjoined twins were scheduled for MRI. We have three MRI suites in one complex and all are equipped with MRI compatible anesthesia workstations. Two separate anesthesia teams, two sets of MRI compatible workstations, monitors, equipment, drugs, infusion pumps and suction were arranged. We planned to shift a second workstation from one of the other suites. MRI compatible full oxygen (O2) cylinders were ensured for both workstations. MRI suite-I had two pipeline sources of O2, and one each for nitrous oxide, air and suction units. We planned O2, nitrous oxide, isoflurane for maintenance of anesthesia for twin-1 and O2, air, isoflurane for twin-2. We noticed that the anesthesia workstation of MRI suite-II did not have compatible gas pipeline connection to be fitted in suite-I. There was no separate compatible tubing to connect the workstation to wall gas outlets. We had two options; first, to use 100% O2 from cylinder without any air or nitrous oxide due to unavailability of MRI compatible nitrous oxide and air cylinder. Second, to use workstation from suite-III. We decided to use the workstation from the suite-III which had compatible tubing. Case was done uneventfully. We observed presence of different terminal wallmounts in two adjacent MRI suites. MRI suites, I and III had quick connect probes with Geometric Index Safety System and MRI suite-II had quick connect probes with indexing collars for oxygen, nitrous oxide and air [Figure 1a and b].[2,3] Recovery room had probes with pin index safety system in the terminal wall-mount outlet [Figure 1c]. We noticed that MRI suites were built by different companies and all the equipment needed in the suite including anesthesia machine, monitor, wall mount assembly for gases etc., were provided by that particular company. Breakdown of anesthesia workstation requiring repair or replacement is not uncommon. Anesthesia for conjoined twins requires utilization of 2 anesthesia workstations in a single room. All workstations in a hospital complex should have same terminal wall mount assemblies and same hose pipe connectors for ease of exchange of workstation in any given scenario. We did not find any guidelines regarding types of wall mount assembly and pipeline connectors in one unit/complex. This may have led to installation of wall-mounts in non-uniform way.Figure 1: Different types of terminal wall mount gas outlets at MRI complex. (1a). Quick connect with geometric index safety system. (1b). Quick connect with indexing collars safety system. (1c). Quick connect with pin index safety systemWe suggest that there should be a central committee in every hospital which must include at least one anesthesiologist along with other technical experts who can contribute in planning and designing of all areas requiring anesthesia services including operation theatre complex, recovery room, radio-diagnostics, radio-therapeutics, Cath-lab, Intensive Care unit, emergency room and similar areas. This team should make sure that there is uniformity in terminal wall mount all across the hospital to avoid such issues. Financial support and sponsorship Nil. Conflicts of interest There are no conflicts of interest.

Anesthesia For Laparoscopic Cholecystectomy In A Patient With Transverse Myelitis: A Case Report

Background: Transverse Myelitis is a rare inflammatory disorder of the spinal cord presenting with sensory, motor, and autonomic dysfunction. Patients of transverse myelitis may present to operation theater for a variety of surgical procedures. The debilitating nature of the disease and interaction with anesthetic agents poses serious challenges during perioperative period. Choice of anesthesia is debatable but the complication following anesthesia can be prevented with thorough preoperative preparation and judicious use of anesthetic agent with neuromuscular monitoring. We present a successful conduction of laparoscopic cholecystectomy in a patient with transverse myelitis.&#x0D; Case Presentation: A 55-year-old female who was a known case of transverse myelitis presented for laparoscopic cholecystectomy to remove a gall bladder polyp. Except for weakness in bilateral lower limbs which had improved since her diagnosis of transverse myelitis two months back, she had no significant past medical and surgical history. Considering the grave possibility of malignant potential in polyp, cholecystectomy was urgent. Her vitals were within normal limits. Other systemic examinations revealed no abnormalities. She was planned under general anesthesia with avoidance of muscle relaxants and intraoperative use of bispectral index and train-of-four monitoring. The intra-operative period was successfully managed with propofol induction, fentanyl as analgesia, I-gel for maintenance of airway, and isoflurane for maintenance of anesthesia. Bispectral index was targeted to 40-60. Intra-operative, and post-operative period was uneventful and she had no exacerbation in her symptoms in the subsequent follow-up.&#x0D; Conclusion: As transverse myelitis is an uncommon condition and often not encountered routinely, the patient present real anesthetic challenge for an unsuspecting anesthesiologist. The successful management of such case especially with the use of novel anesthetic monitoring technique provide us with sufficient evidence that dreadful complications of transverse myelitis like exacerbation of motor, sensory and autonomic dysfunction can be avoided.

Haemodynamic changes and emergence delirium in children undergoing isoflurane general anaesthesia for dental treatments: effect of propofol administration

ObjectiveTo evaluate the effects of administration of 1 mg·kg−1 propofol before the end of surgery on the haemodynamic values and incidence of emergence delirium in paediatric dental patients retrospectively. MethodsNinety-seven children aged between 2 and 12 who were treated under general anaesthesia in Yeditepe University Faculty of Dentistry were included. Midazolam for premedication and intravenous propofol for induction and isoflurane for maintenance of anaesthesia were used. One mg·kg−1 propofol was administered before extubation and 15 min before the end of surgery. The monitorized haemodynamic values including heart rate, oxygen saturation in periferic circulation, CO2 in expirium and body temperature were collected from patient files. The level of emergence delirium was measured using the Pediatric Anaesthesia Emergence Delirium Scale. ResultsThirty-nine girls and fifty-eight boys (5.21 ± 2.32) were investigated. A statistically significant increase was found in the mean heart rate during induction and end of intubation. Expired CO2 significantly increased after the end of intubation and decreased at the end of anaesthesia. According to the Pediatric Anaesthesia Emergence Delirium Scale none of the patients were scored as emergence delirium and 52,78% of the children were scored as 0. ConclusionsWhen administration of single dose of propofol is used for the prevention of Emergence Delirium, constant monitoring of expired CO2 values during and after the end of intubation is essential. It can be suggested that administration of a single dose of 1 mg·kg−1 propofol prevents emergence delirium in paediatric dental patients; nevertheless this finding should be confirmed with prospective clinical trials.

Universal Anesthesia Machine: Clinical Application in an Austere, Resource-Limited Environment.

In austere environments, the safe administration of anesthesia becomes challenging because of unreliable electrical sources, limited amounts of compressed gas, and insufficient machine maintenance capabilities. Such austere environments exist in battlefield medicine, in low- and middle-income countries (LMICs), and in areas struck by natural disasters. Whether in military operations or civilian settings, the Universal Anesthesia Machine (UAM) (Gradian Health Systems, New York, New York) is a draw-over device capable of providing safe and effective general anesthesia when external oxygen supplies or reliable electrical sources are limited. This brief report discusses a proof-of-concept observational study demonstrating the clinical utility of the UAM in a resource-limited area. This observational study of 20 patients in Haiti who underwent general anesthesia using the UAM highlights the device's capability to deliver anesthesia intraoperatively in a resource-limited LMIC clinical setting. Preoxygenation was achieved with the UAM's draw-over oxygen supply. Patients received acetaminophen for analgesia, dexmedetomidine for preinduction anesthesia, and succinylcholine for paralysis. After induction, the UAM provided a mixture of oxygen and isoflurane for maintenance of anesthesia. Manual ventilation was performed using draw-over bellows until spontaneous ventilation recurred, when clinically appropriate, artificial airways were removed. Intraoperative medication was administered at the anesthesiologist's discretion. The institutional review board at the U.S. anesthesiologists' affiliated institution and the Haitian hospital approved this study; patients were consented in their native language. Two anesthesiologists used the UAM to deliver general anesthesia to 20 patients in a Haitian hospital without access to an external oxygen supply, reliable power grid, or opioids. The patients' average age was ~40years, and 90% of them were male. Most of the cases were herniorrhaphy (50%) and hydrocelectomy (25%) surgeries. The median American Society of Anesthesiologists (ASA) score was 2; 45% of the patients had an ASA score of 1, and none had an ASA score >3. Of the 20 cases, 55% of patients received an endotracheal tube, and 40% received a laryngeal mask airway; for one patient, only a masked airway was used. Every patient was discharged on the day of the surgery. No complications occurred in the perioperative or 1-month follow-up period. The UAM can be used where a lack of resources and training exist because of its simple design, built-in oxygen concentrator, and capacity to revert from continuous-flow to draw-over anesthesia in the event of a power failure or if external oxygen supplies are unavailable. We believe the UAM addresses some of the shortcomings of modern anesthesia machines and has the potential to improve the delivery of safe general anesthesia in combat and austere scenarios. Further studies could consider different types of surgeries than those reported here and involve more complex patients. Studies involving alternative anesthetic agents and non-anesthesiologist personnel are also needed. Overall, this brief report detailing the use of the UAM following a natural disaster in a LMIC is proof of concept that the machine can provide reliable anesthesia for surgical procedures in austere and resource-limited environments, including disaster areas and modern combat zones.

Comparison Between Administration of Midazolam and Propofol at the End of Anesthesia for Prevention of Emergence Agitation in Children

Background: Comparison of midazolam and propofol has been done hoping to reduce the incidence rates of emergence agitation (EA) after anesthesia. Both drugs however, are still under inspection as for their effect on EA after using Isoflurane for maintenance of anesthesia. Objectives: This study was designed for measuring the effect of either propofol or midazolam near the end of tonsillectomy operation on incidence of EA during the recovery phase. Methods: In this randomized, double-blind study, 90 children, aged 5 to 15, undergoing anesthesia with Isoflurane were randomly assigned to three groups receiving either propofol (group P), midazolam (group M) or saline (group S) near the end of anesthesia. Severity and incidence of EA were then calculated using the pediatric anesthesia emergence delirium (PAED) scale. Results: The mean PAED score in group P was (2.87 ± 2.69) and (1.90 ± 2.55) in group M. Both were significantly lower than group S (7.60 ± 3.78) (P 0.05). No significant difference was found between all groups for apnea and laryngospasm (P > 0.05). Conclusions: Administration of either midazolam or propofol near the end of operation may result in reduction of EA in children undergoing tonsillectomy after Isoflurane anesthesia.

The Effect of Inhalation Anesthesia with Hyperventilation and Total Intravenous Anesthesia on Intracranial Pressure Control in Pediatrics with Craniosynostosis Surgery: A Randomized Clinical Trial

Background: Intracranial pressure (ICP) control is one of the anesthesiologist challenges in craniosynostosis repair surgery, especially in multiple sutures involvement. The aim of this study was comparing the effect of two anesthesia methods including inhalation with hyperventilation and total intravenous anesthesia (TIVA) on ICP control and surgeon satisfaction in pediatrics with craniosynostosis surgery. Materials and Methods: In this randomized clinical trial study, 40 pediatric patients with American society of anesthesiologists (ASA) І-ІІ, 6 months to 2 years old were included. All of the patients were scheduled for craniosynostosis repair at Mofid Children Hospital, Tehran, Iran, in May 2016 to January 2017. The patients were randomly divided into two groups. In hyperventilation group, patients received isoflurane for maintenance of anesthesia and hyperventilation (Paco2=25-30 mmHg) established during surgery. The total intravenous anesthesia (TIVA) group received propofol infusion for anesthesia maintenance and Paco2 was maintained 35 mmHg. Intra cranial pressure (ICP) was assessed by surgeon using a 4-point scale. Hemodynamic (mean arterial pressure and heart rate) changes and blood loss were compared between hyperventilation and TIVA groups. Results: The mean age of patients in hyperventilation group was 10.9±3.25 months and in TIVA group was 8.7 ± 2063 months (p=0.11). Fourteen (70%) patients in hyperventilation group and 6 (30%) patients in TIVA group were male (p=0.74). A significant difference was seen in ICP control and surgical condition between hyperventilation and TIVA groups (p=0.032). ICP was controlled better in hyperventilation group. There was no difference in hemodynamic parameters and blood loss between hyperventilation and TIVA groups (p>0.05). Conclusion: This study showed inhalation anesthesia with hyperventilation was more effective than TIVA on ICP control in craniosynostosis surgery.

A comparison of the immunological effects of propofol and isoflurane for maintenance of anesthesia in healthy dogs.

Most anesthetics have an immuno-suppressive effect on cellular and neurohumoral immunity, and research shows that total intravenous anesthesia (TIVA) with propofol has a greater immuno-protective effect than inhalational anesthesia in human medicine. However, in veterinary clinics, these effects remain ambiguous. To clarify the details, we focused on propofol and isoflurane, investigating clinical blood hematology and immunological profiles drawn from healthy dogs under and after two anesthesia techniques. Twelve healthy adult beagles were included in this study, randomly assigned to the propofol anesthesia group (group P: n=6) or the isoflurane anesthesia group (group I: n=6). In both groups, the number of lymphocytes in peripheral blood decreased after 2 hr of anesthesia (2 hr), but group P showed significantly less decrease than group I. For T-lymphocyte subsets examined by flowcytometry, the ratio of CD3+, CD4+ and CD8+ lymphocytes in the peripheral blood mononuclear cell (PBMC) of group P at 2 hr also exhibited a high level compared to group I. Moreover, for mRNA expression of cytokines measured by real-time PCR, the IL2 (pro-inflammatory cytokine) of group P showed no decrease like group I. The IL10 (anti-inflammatory cytokine) of group P also showed no increase like group I, while both cytokines maintained nearly the same level until 2 hr. These results suggest that, compared to propofol, isoflurane had more strongly immuno-suppression caused by anesthesia, and propofol itself might have some immuno-protective effects. Thus, TIVA with propofol might benefit immunological support in the perioperative period of dogs.

Effects of propofol and isoflurane on haemodynamics and the inflammatory response in cardiopulmonary bypass surgery

ABSTRACTCardiopulmonary bypass (CPB) causes reperfusion injury that when most severe is clinically manifested as a systemic inflammatory response syndrome. The anaesthetic propofol may have anti-inflammatory properties that may reduce such a response. We hypothesised differing effects of propofol and isoflurane on inflammatory markers in patients having CBP. Forty patients undergoing elective CPB were randomised to receive either propofol or isoflurane for maintenance of anaesthesia. CRP IL-6, IL-8, HIF-1α (ELISA), CD11 and CD18 expression (flow cytometry), and haemoxygenase (HO-1) promoter polymorphisms (PCR/electrophoresis) were measured before anaesthetic induction, 4 hours post-CPB, and 24 hours later. There were no differences in the 4 hours changes in CRP IL-6, IL-8 or CD18 between the two groups, but those in the propofol group had higher HIF-1α (P=0.016) and lower CD11 expression (P=0.026). After 24 hours, compared to the isoflurane group, the propofol group had significantly lower levels of CRP (P<0.001), IL-6 (P<0.001) and IL-8 (P<0.001), with higher levels CD11 (P=0.009) and CD18 (P=0.002) expression. After 24 hours, patients on propofol had increased expression of shorter HO-1 GT(n) repeats than patients on isoflurane (P=0.001). Use of propofol in CPB is associated with a less adverse inflammatory profile than is isofluorane, and an increased up-regulation of HO-1. This supports the hypothesis that propofol has anti-inflammatory activity.

Comparison of isoflurane and propofol for maintenance of anesthesia in dogs with intracranial disease undergoing magnetic resonance imaging

ObjectiveTo compare isoflurane and propofol for maintenance of anesthesia and quality of recovery in client-owned dogs with intracranial disease undergoing magnetic resonance imaging (MRI). Study designProspective, randomized, clinical trial. AnimalsTwenty-five client-owned dogs with intracranial pathology, 13 females and 12 males, ages 11 months to 13 years, weighing between 3.0 and 48.0 kg. MethodsEach dog was randomly assigned to receive propofol or isoflurane for maintenance of anesthesia. All dogs were not premedicated, were administered propofol intravenously to effect for induction, intubated and mechanically ventilated to maintain an end-tidal carbon dioxide tension 30–35 mmHg (4.0–4.7 kPa). Temperature and cardiac output were measured pre- and post-MRI. Scores for mentation, neurological status, ease of maintenance, and recovery were obtained pre- and post-anesthesia. Pulse oximetry, end-tidal gases, arterial blood pressure, heart rate (HR) and requirements for dopamine administration to maintain mean arterial pressure (MAP) >60 mmHg were recorded throughout anesthesia. ResultsEnd-tidal isoflurane concentration was 0.73 ± 0.35% and propofol infusion rate was 292 ± 119 μg kg−1 minute−1. Cardiac index was higher, while HR was lower, with propofol than isoflurane in dogs younger than 5 years, but not in older dogs. Dogs maintained with isoflurane were 14.7 times more likely to require dopamine than propofol dogs. Mentation and maintenance scores and temperature were not different. MAP and diastolic arterial pressure were higher in the propofol group. Recovery scores were better with propofol, although times to extubation were similar. Change in neurological score from pre- to post-anesthesia was not different between treatments. ConclusionsDogs maintained with propofol during MRI had higher arterial pressures, decreased requirements for dopamine, and better recovery scores, compared to dogs maintained with isoflurane. Clinical relevancePropofol anesthesia offered cardiovascular and recovery advantages over isoflurane during MRI in dogs with intracranial disease in this study.

Clinicophysiological and haemodynamic effects of fentanyl with xylazine, medetomidine and dexmedetomidine in isoflurane-anaesthetised water buffaloes (&lt;i&gt;Bubalus bubalis&lt;/i&gt;)

The present study was undertaken to investigate the sedative, analgesic and clinical effects of xylazine, medetomidine and dexmedetomidine with fentanyl as pre-anaesthetics in water buffaloes and to compare the dose-sparing effect of xylazine, medetomidine and dexmedetomidine on thiopental for induction and isoflurane for maintenance of anaesthesia in water buffaloes. Six male water buffaloes randomly received intravenous fentanyl (5.0 µg/kg body weight) and xylazine (0.05 mg/kg body weight), fentanyl (5.0 µg/kg body weight) and medetomidine (2.5 µg/kg body weight), fentanyl (5.0 µg/kg body weight) and dexmedetomidine (5.0 µg/kg body weight) at weekly intervals in groups I1, I2 and I3, respectively. After 15 min, the animals were restrained in right lateral recumbency and anaesthesia was induced by 5% thiopental sodium administered intravenously. The intubated animal was connected to the large animal anaesthesia machine and isoflurane in 100% oxygen (5 L/min) was insufflated for 60 min. The treatments were compared by clinicophysiological, haematobiochemical and haemodynamic parameters. Fentanyl-medetomidine and fentanyl-dexmedetomidine produced more cardiovascular depression during the pre-anaesthetic period but less depression of cardio-respiratory dynamics in the post induction and maintenance period. Quicker recovery was recorded in I2 and I3 groups. A lower dose of thiopental was required in group I3 (4.33 mg/kg ± 0.66 mg/kg) than in groups I2 (4.41 mg/kg ± 0.98 mg/kg) and I1 (4.83 mg/kg ± 0.79 mg/kg). The dose of isoflurane was less in group I3 (45.50 mL ± 5.45 mL) than in group I1 and I2 (48.66 mL ± 5.10 mL and 48.00 mL ± 6.38 mL). Better anaesthesia was recorded with fentanyl-dexmedetomidine-thiopental-isoflurane (group I3) than with fentanyl-medetomidine-thiopental-isoflurane (group I2) and fentanyl-xylazine-thiopental-isoflurane (group I1). Fentanyl-medetomidine and fentanyl-dexmedetomidine were better pre-anaesthetic agents in comparison to fentanyl-xylazine for thiopental and isoflurane anaesthesia. Fentanyl-dexmedetomidine-thiopental-isoflurane and fentanyl-medetomidine-thiopental-isoflurane produced effective surgical anaesthesia and were found to be safe, as cardio-pulmonary functions were well preserved during maintenance anaesthesia with no deleterious effect on vital organ functions in water buffaloes.

Clinical efficacy and safety of dexmedetomidine used as a preanesthetic prior to general anesthesia in cats

To evaluate the clinical efficacy of dexmedetomidine as a preanesthetic medication administered prior to anesthetic induction with ketamine or propofol and with or without isoflurane for maintenance of anesthesia. Randomized, blinded, controlled clinical trial. 184 client-owned cats. Cats requiring general anesthesia for short or long procedures were assigned to receive 1 of 4 preanesthetic and induction drug combinations (dexmedetomidine and ketamine, placebo [saline {0.9% NaCl} solution] and ketamine, dexmedetomidine and propofol, or placebo and propofol). Cats undergoing long procedures received isoflurane for maintenance of anesthesia. Administration of dexmedetomidine prior to anesthetic induction with ketamine significantly increased the intubation success rate (57/64 [89%]), compared with the success rate for the placebo (4/37 [11 %]); significantly reduced the median induction dose of propofol (≤ 5.1 mg/kg [2.32 mg/lb]), compared with that for the placebo (≤ 10.5 mg/kg [4.77 mg/lb]); and significantly reduced the isoflurane concentration (1.5%) required for anesthesia maintenance, compared with that for the placebo (3.0%). Postoperatively, fewer cats receiving dexmedetomidine required rescue analgesia, and cats had lower pain scores for at least 2 hours after surgery, compared with results for cats receiving the placebo. Heart rate was lower during the procedure and respiratory rate and rectal temperature were lower during and after the procedure for cats receiving dexmedetomidine. More cats that received dexmedetomidine had emesis and pale mucous membranes, compared with the number of cats with those signs that received placebo. Dexmedetomidine as a preanesthetic was efficacious for clinical use in cats requiring general anesthesia.

Evaluation of the effects of thiopental, propofol, and etomidate on glomerular filtration rate measured by the use of dynamic computed tomography in dogs

To evaluate the effects of thiopental, propofol, and etomidate on glomerular filtration rate (GFR) measured by the use of dynamic computed tomography in dogs. 17 healthy Beagles. Dogs were randomly assigned to receive 2 mg of etomidate/kg (n = 5), 6 mg of propofol/kg (7), or 15 mg of thiopental/kg (5) during induction of anesthesia; anesthesia was subsequently maintained by isoflurane evaporated in 100% oxygen. A 1 mL/kg dosage of a 300 mg/mL solution of iohexol was administered at a rate of 3 mL/s during GFR measurement. Regions of interest of the right kidney were manually drawn to exclude vessels and fatty tissues and highlight the abdominal portion of the aorta. Iohexol clearance per unit volume of the kidney was calculated by use of Patlak plot analysis. Mean ± SD weight-adjusted GFR of the right kidney after induction of anesthesia with thiopental, propofol, and etomidate was 2.04 ± 0.36 mL/min/kg, 2.06 ± 0.29 mL/min/kg, and 2.14 ± 0.43 mL/min/kg, respectively. However, no significant differences in weight-adjusted GFR were detected among the treatment groups. Results obtained for the measurement of GFR in anesthetized dogs after anesthetic induction with etomidate, propofol, or thiopental and maintenance with isoflurane did not differ significantly. Therefore, etomidate, propofol, or thiopental can be used in anesthesia-induction protocols that involve the use of isoflurane for maintenance of anesthesia without adversely affecting GFR measurements obtained by the use of dynamic computed tomography in dogs.

Anesthesia for videoscopic left cardiac sympathetic denervation in children with congenital long QT syndrome and catecholaminergic polymorphic ventricular tachycardia – a case series

To describe our experience in the anesthetic management of pediatric patients who have undergone left cardiac sympathetic denervation (LCSD) for congenital long QT syndrome (LQTS) and catecholaminergic polymorphic ventricular tachycardia (CPVT). Long QT syndrome and CPVT predispose patients to ventricular arrhythmias and sudden death. One treatment option for these patients is LCSD. When these patients present for LCSD or other surgical procedures, anesthetic management is challenging, as many medications may exacerbate QT prolongation. Retrospective review of the electronic medical records of 22 pediatric patients who underwent LCSD between November 2005 and December 2008. Six patients (27%) received midazolam as a premedication. Eleven patients (50%) underwent inhalation induction with sevoflurane. Eighty-six percentage received either sevoflurane or isoflurane for maintenance of anesthesia, while the remaining 14% received a propofol infusion. Nine patients (41%) received esmolol infusions intraoperatively, while one patient (4.5%) received a labetalol infusion. Three patients (14%) received lidocaine infusions. no significant cardiac or other events occurred in any of these patients in the perioperative period. Important anesthetic considerations in this population include avoidance of sympathetic stimulation, correction of any abnormal electrolytes, and the immediate availability of a defibrillator and magnesium sulfate to treat arrhythmias. Anxious patients may benefit from premedication to reduce sympathetic tone. We have safely used both volatile agents and propofol for induction and maintenance of anesthesia. In our experience, intraoperative infusions of beta-blockers and lidocaine seem to be helpful in reducing arrhythmogenic potential, especially in patients with profound QT prolongation.

Comparison of the arterial blood gas, arterial oxyhaemoglobin saturation and end-tidal carbon dioxide tension during sevoflurane or isoflurane anaesthesia in rabbits

The effects of sevoflurane or isoflurane on arterial blood gas, arterial oxyhaemoglobin saturation and end-tidal CO2 tension were monitored during induction and maintenance of anaesthesia in 10 premedicated New Zealand White (NZW) rabbits.For induction, the anaesthetic agents were delivered via a face-mask. After induction was completed, an endotracheal tube was introduced for maintenance of anaesthesia for a period of 90 minutes. Changes in heart rate, respiratory rate, arterial blood gas, arterial oxyhaemoglobin saturation, blood pH and end-tidal CO2 tension were recorded. Although sevoflurane and isoflurane produce similar cardiopulmonary effects in premedicated rabbits, sevoflurane provides a smoother and faster induction because of its lower blood/gas partition coefficient. Thus sevoflurane is probably a more suitable agent than isoflurane for mask induction and maintenance. Its lower blood solubility also makes sevoflurane more satisfactory than isoflurane for maintenance of anaesthesia because it allows the anaesthetist to change the depth of anaesthesia more rapidly.

Clonidine for the prevention of emergence agitation in young children: efficacy and recovery profile

Emergence agitation (EA) is a common postoperative problem in young children who have received sevoflurane and isoflurane for general anesthesia. This randomized, double-blinded study evaluated the efficacy of intraoperative clonidine in reducing EA, and describes its recovery profile. With Institutional Review Board approval and informed consent, children undergoing brief, minimally painful procedures were studied. All children received preemptive analgesia with acetaminophen and ketorolac, sevoflurane for induction, and isoflurane for maintenance of anesthesia. Children received either 2 microg.kg(-1) clonidine or placebo intravenously (i.v.) following induction of anesthesia. Children were observed postoperatively for behavior and side effects, and their parents were telephoned the next day to determine postdischarge recovery characteristics. One hundred and twenty children were included in this study: 59 of whom received clonidine, and 61 placebo; 41% of those in the placebo group exhibited moderate-severe EA compared with only 22% of those in the clonidine group (P < 0.03). Compared with those who received placebo, children who received clonidine awakened more slowly (22 min vs 14 min), had a longer postanesthesia care unit stay (57 min vs 46 min), and experienced sleepiness more frequently after discharge (75% vs 39%; all comparisons significant at P < 0.03). There were no adverse cardiorespiratory events in either group. Findings demonstrate that i.v. clonidine administered after induction of anesthesia significantly reduces the incidence of EA in young children, but is associated with sleepiness postoperatively.

Pressure support ventilation with the ProSeal® laryngeal mask airway. A comparison of sevoflurane, isoflurane and propofol

There are no data about the influence of anaesthetics on cardiovascular variables during pressure support ventilation of the lungs through the laryngeal mask airway. We compared propofol, sevoflurane and isoflurane for maintenance of anaesthesia with the ProSeal laryngeal mask airway during pressure support ventilation. Sixty healthy adults undergoing peripheral musculo-skeletal surgery were randomized for maintenance with sevoflurane end-tidal 2%, isoflurane end-tidal 1.1% or propofol 6 mg kg(-1) h(-1) in oxygen 33% and air. Pressure support ventilation comprised positive end-expiratory pressure set at 5 cmH2O, and pressure support set 5 cmH2O above positive end-expiratory pressure. Pressure support was initiated when inspiration produced a 2 cmH2O reduction in airway pressure. A blinded observer recorded cardiorespiratory variables (heart rate, mean blood pressure, oxygen saturation, airway occlusion pressure, respiratory rate, expired tidal volume, expired minute volume and end-tidal CO2), adverse events and emergence times. Respiratory rate and minute volume were 10-21% lower, and end-tidal CO2 6-11% higher with the propofol group compared with the sevoflurane or isoflurane groups, but otherwise cardiorespiratory variables were similar among groups. No adverse events occurred in any group. Emergence times were longer with the propofol group compared with the sevoflurane or isoflurane groups (10 vs. 7 vs. 7 min). Lung ventilation is less effective and emergence times are longer with propofol than sevoflurane or isoflurane for maintenance of anaesthesia during pressure support ventilation with the ProSeal laryngeal mask airway. However, these differences are small and of doubtful clinical importance.

Postoperative Coma in a Child with Carnitine Palmitoyltransferase I Deficiency

Postoperative Coma in a Child with Carnitine Palmitoyltransferase I Deficiency

In rats breathing from a nonrebreathing system, substitution of desflurane for isoflurane toward the end of anesthesia incompletely restores the time of recovery toward that of desflurane.

The lower solubility of desflurane allows a more rapid emergence from anesthesia than after anesthesia with the more soluble but less expensive anesthetic, isoflurane. Some practitioners use isoflurane for maintenance of anesthesia, crossing over to desflurane later in maintenance in an attempt to combine the cost-effectiveness of isoflurane with the rapid emergence from desflurane. We hypothesized that this maneuver would not accomplish its goals. Twenty-four male Sprague-Dawley rats received 1.2 minimum alveolar anesthetic concentration (MAC) of desflurane for the final 15, 30, or 60 min of a 2-h, 1.2-MAC isoflurane anesthetic in a nonrebreathing anesthesia system. We measured the time from cessation of anesthetic administration to the time each rat righted himself twice. Immediately after righting for the second time, we tested each rat's ability to remain atop a rotating rod (Rota-Rod) for 60 s continuously. Early (righting reflex) and late (Rota-Rod) recovery occurred more rapidly (P < 0.001) after 120 min of anesthesia with desflurane alone than after 120 min of anesthesia with isoflurane alone. A cross-over period of 30 min or longer produced a righting reflex time that did not differ from that found with desflurane alone, but a 15-min cross-over did not. Progressively longer cross-over periods led to proportionally better Rota-Rod performance, but no cross-over duration produced the rapidity of recovery seen with desflurane alone. We concluded that in a nonrebreathing system, switching to desflurane during the last 30 min of anesthesia substantially improved early recovery but produced a much smaller improvement in later recovery. The newer inhaled anesthetics offer the advantage of lower solubility, and thus more rapid emergence from anesthesia, than do the older inhaled anesthetics. However, they can be more expensive to use. This study demonstrates that substituting the newer anesthetic, desflurane, toward the end of anesthesia for an older anesthetic of greater solubility, isoflurane, does not produce recovery comparable to that of desflurane alone. Furthermore, this technique can be more costly than using desflurane throughout anesthesia.

Comparison of propofol with isoflurane for maintenance of anesthesia in patients with chronic obstructive pulmonary disease: Use of pulmonary mechanics, peak flow rates, and blood gases

Patients with chronic obstructive pulmonary disease (COPD) are usually anesthetized with an inhalation agent. After Institutional Review Board approval, informed consent was obtained from 60 patients with moderate to severe COPD according to a preoperative severity scoring system, which took into account history and objective findings. By using objective criteria, such patients were randomly assigned to receive propofol (group I) or isoflurane (group II) as primary maintenance agents. Preoperative and postoperative arterial blood gases, peak expiratory flow rates (PEFR), and chest X-rays were compared. Total dynamic compliance (C DYN) and V 1 (1% volume exhaled in first second) were measured using Pitot tube sidestream spirometry. A 1,000-mL super-syringe was used to measure total static compliance (C ST). Measurements were recorded postintubation, midanesthesia, and pre-extubation. All patients received fentanyl, lidocaine, and propofol, 1.5 to 2.0 mg/kg, for induction. Succinylcholine, 1-1.5 mg/kg, was administered to facilitate intubation. Maintenance was with N 2O-O 2, vecuronium, and either propofol ( n = 30) or isoflurane ( n = 30). Both group showed decreases in postoperative PaO 2, SaO 2, and PEFR ( p < 0.05), but there were no differences between groups ( p > 0.05). There were no significant chest X-ray differences. There were no differences between groups with respect to intraoperative pulmonary mechanics ( p > 0.05). The only difference between groups was an increase in postoperative PaCO 2 in group I and a decrease in group II ( p < 0.05). Use of Pitot tube sidestream spirometry is a practical and noninvasive technique for monitoring pulmonary mechanics during anesthesia. It was concluded that propofol and isoflurane as primary maintenance anesthetic agents are objectively and clinically equivalent in patients with COPD.