Sevoflurane and propofol decrease intraocular pressure equally during non-ophthalmic surgery and recovery

Background. To provide good control of intraocular pressure(IOP) during anaesthesia and surgery, we conducted a study comparingthe effects on IOP during maintenance and recovery of sevofluranevs propofol anaesthesia in 33 patients (ASA I–II) undergoingelective non- ophthalmic surgery. Methods. Anaesthesia was induced with propofol 2 mg kg^–1,fentanyl 2 µg kg^–1 and vecuronium 0.1 mg kg^–1.Patients were allocated randomly to receive either propofol4–8 mg kg^–1 h^–1 (group P; n=16)or 1.5–2.5 vol% sevoflurane (group S; n=17) for maintenanceof anaesthesia. Fentanyl 2–4 µg kg^–1was added if necessary. The lungs were ventilated with 50% airin oxygen. Blood pressure, heart rate, oxygen saturation andend-tidal carbon dioxide were measured before and throughoutanaesthesia and in the recovery room. IOP was determined withapplanation tonometry (Perkins) by one ophthalmologist blindedto the anaesthetic technique. Results. There was a significant decrease in IOP after inductionand during maintenance of anaesthesia in both groups. No significantdifferences in IOP between the two groups was found. Conclusion. Sevoflurane maintains the IOP at an equally reducedlevel compared with propofol. Br J Anaesth 2002; 89: 764–6     

Effects of remifentanil and fentanyl on intraocular pressure during the maintenance and recovery of anaesthesia in patients undergoing non-ophthalmic surgery

BACKGROUND AND OBJECTIVE: To compare the effects of remifentanil and fentanyl on intraocular pressure during the maintenance and recovery of anaesthesia in patients undergoing elective non-ophthalmic surgery. METHODS: Thirty-two patients (ASA I-II) were randomized into two groups to receive either a continuous infusion of remifentanil (0.25-0.5 microg kg(-1) min(-1), n =16, Group R) or an intermittent bolus of fentanyl (2-5 microg kg(-1), n = 16, Group F) during the maintenance of anaesthesia. For the induction of anaesthesia, Group R received remifentanil 1 microg kg(-1) and Group F received fentanyl 2 microg kg(-1); both groups then received propofol 2 mg kg(-1) with vecuronium 0.1 mg kg(-1). Anaesthesia in both groups was maintained with a continuous infusion of propofol 4-8 mg kg(-1) h(-1). Ventilation of the lungs was controlled to a constant end-tidal PCO2 of 4.7-5.4 kPa. Blood pressure, electrocardiography, heart rate and oxygen saturation were monitored throughout anaesthesia. Intraocular pressure was determined before surgery, during the maintenance of anaesthesia, 2 min after emergence and in the recovery room using a Perkins hand-held applanation tonometer by an ophthalmologist blinded to the anaesthetic technique. RESULTS: After induction of anaesthesia, a significant decrease in intraocular pressure in the remifentanil group from 13.6 +/- 2.6 to 7.1 +/- 3.1 mmHg (P < 0.001) and in the fentanyl group from 13.7 +/- 2.2 to 9.7 +/- 3.4 mmHg (P < 0.001) was observed and maintained during anaesthesia. Thirty minutes after the end of anaesthesia, intraocular pressure returned to baseline values in both groups (remifentanil: 13.9 +/- 2.8 mmHg, P = 0.28; fentanyl: 13.6 +/- 2.3 mmHg, P = 0.59). The intraocular pressure and haemodynamic variables did not differ significantly between the two groups (intraocular pressure, P = 0.7327; blood pressure, P = 0.1295; heart rate, P = 0.8601). CONCLUSIONS: Remifentanil maintains intraocular pressure at an equally reduced level compared with fentanyl.     

Desflurane induces more cerebral vasodilation than isoflurane at the same A-line autoregressive index level

BACKGROUND: Clinical use of desflurane in neuroanesthesia remains under debate. Comparison of dose-dependent vasodilatory properties between desflurane and isoflurane, the more traditional volatile agent for clinical neuroanesthesia, requires equianesthetic dosing of the agents. Reproducible neurophysiological measurements of the level of anesthesia in an individual, e.g. the A-line autoregressive index (AAI), can be used for an equipotent dosage of two volatile agents in the same individual. METHODS: Desflurane and isoflurane, in randomized order, were titrated to a stable AAI level of 15-20 in 18 ASA I or II patients. The mean flow velocity (Vmca) and pulsatility index (PI) in the middle cerebral artery were then measured with transcranial Doppler at an end-tidal CO(2) concentration of 4.4%. RESULTS: For desflurane Vmca was 11% higher [95% confidence interval (CI), 5-18%; P = 0.0020] and PI was 13% lower (95% CI, 3-23%; P = 0.0083) than for isoflurane. The mean arterial blood pressure did not differ between the agents. The fraction of MAC necessary for the intended AAI level was 35% lower (95% CI, 20-49%; P = 0.00016) with desflurane than with isoflurane. CONCLUSION: Desflurane was associated with more cerebral vasodilation than isoflurane at the same depth of anesthesia, as indicated by the AAI. This attributes further reason for caution in the use of desflurane in clinical neuroanesthesia. The difference between desflurane and isoflurane in the MAC fractions required for the same AAI level confirms the limitations of MAC in defining the level of anesthesia.     

异丙酚和异氟醚对食管癌手术患者围术期细胞因子平衡的影响

目的研究异丙酚和异氟醚对开胸食管癌手术患者围术期炎性与抗炎性细胞因子平衡的影响.方法择期食管癌手术患者25例,随机分为两组.异氟醚组平均呼末浓度为0.6%,异丙酚组微泵输入剂量为6mg@kg-1@h-1.监测麻醉前、手术开始切皮时、进胸后2h、鼓肺后60min、术后1h、4h、24h血清IL-6、IL-8、IL-10的浓度.观察围术期血液动力学变化及术后临床征象.结果两组进胸后各时点IL-6、IL-8、IL-10的浓度均较术前显著增加(P＜0.01),炎性与抗炎性细胞因子分别于术后1h、4h达到高峰.IL-6组问比较无显著差异,异氟醚组膨肺后60min至术后4h各时点IL-8增加的幅度明显高于异丙酚组(P＜0.05),但术后24h两组无差别.异丙酚组术后1h、4h、24h IL-10的产生均显著高于异氟醚组(P＜0.05或P＜0.01).结论临床剂量的异丙酚促进IL-10的产生,而异氟醚促进了IL-8的分泌,但麻醉选择对于细胞因子平衡的干预尚未影响到机体的免疫自稳.     

Effects of propofol on intraocular pressure in surgery of strabismus in children

Propofol was assessed for eye surgery in 20 children. ASA group I or II, 2-14 year-old, randomly assigned to 2 equal groups. Premedication, analgesia and muscle paralysis were similar in both groups. Group P patients were given an induction dose of 4 mg.kg-1 propofol, followed by an infusion of 15 mg.kg-1.h-1 for the first half hour, and then 10 mg.kg-1.h-1 to maintain anaesthesia. Group C patients were given 10 mg.kg-1 thiopentone for induction and halothane for maintenance. The quality of anaesthesia was assessed by monitoring adverse effects, heart rate, blood pressure, the length of anaesthesia, the delay of the first spontaneous breath and eye opening, and extubation. Intraocular pressure was measured before and 3 min after intubation, and 5 min after extubation. The quality of anaesthetic induction and maintenance were very similar in both groups. Pain occurred more frequently at the injection site with propofol (p less than 0.01). Children in group P recovered more quickly, and extubation was possible much earlier in this group (p less than 0.05). However, restlessness was significantly more frequent in group P (n = 9) than in group C (n = 1) (p less than 0.01). Systolic, diastolic blood pressure and heart rate were significantly lower in group P (p less than 0.05; 0.001; 0.001 respectively). No significant decrease in intraocular pressure in both groups was observed. The use of propofol for eye surgery in children is acceptable, despite some restlessness during recovery.     

Effects of propofol on intraocular pressure during the induction of anesthesia

A study of variations in intraocular pressure during anaesthetic induction with propofol was carried out in 20 patients. There were compared with the effects caused by thiopentone. The intraocular pressure fell by 50%; this was very significant. Besides, a more important fall in blood pressure was seen with propofol (congruent to 15%) than with thiopentone (less than 10%). Complete recovery was faster after an anaesthesia with propofol. This drug seemed to be particularly interesting in ophthalmologic anaesthesia in elderly people.     

Desflurane increases intracranial pressure more and sevoflurane less than isoflurane in pigs subjected to intracranial hypertension

Desflurane and sevoflurane may have advantages over isoflurane in neuroanesthesia, but this is still under debate. A porcine model with experimental intracranial hypertension was used for paired comparison of desflurane, sevoflurane, and isoflurane with respect to the effects on cerebral blood flow (CBF), cerebrovascular resistance (CVR), and intracranial pressure (ICP). The agents, given in sequence to each of six pigs, were compared at 0.5 and 1.0 minimal alveolar concentrations (MAC) and three mean arterial blood pressure (MAP) levels (50, 70, and 90 mm Hg) at normocapnia and one MAP level (70 mm Hg) at hypocapnia. MAC for each agent had been previously determined in a standardized manner for comparison reliability. CBF was measured with Xe. MAP was lowered by inflation of a balloon catheter in the inferior caval vein and raised by inflation of a balloon catheter in the descending aorta. ICP was measured intraparenchymally. Two Fogarty catheters positioned extradurally were inflated to a baseline ICP of 20 to 22 mm Hg at 0.2 MAC of each agent. CBF and ICP with the three agents at normocapnia and MAP 70 and 90 mm Hg at both 0.5 and 1.0 MAC were as follows (P < 0.05): desflurane > isoflurane > sevoflurane. None of the agents abolished CO2 reactivity. High-dose desflurane resulted in a higher CBF at hypocapnia than corresponding doses of sevoflurane or isoflurane, but there were no significant differences between the agents in ICP at hypocapnia. The present study showed that desflurane increased ICP more and sevoflurane less than isoflurane during normoventilation, but the differences disappeared with hyperventilation.     

Effect of propofol and isoflurane anaesthesia on the immune response to surgery

There are two major subpopulations of peripheral helper T lymphocytes: T helper 1 (Th1) and T helper 2 (Th2) cells. Surgical stress increases the number of Th2 cells, and decreases that of Th1 cells, resulting in a decrease in the Th1/Th2 ratio, and, consequently, in suppressed cell-mediated immunity. Since anaesthesia can suppress the stress response to surgery, it may inhibit the decrease in the Th1/Th2 ratio. Using flow cytometry, we studied whether propofol anaesthesia (n = 9) or isoflurane anaesthesia (n = 9) had more effect on the decrease in the Th1/Th2 ratio after surgery in patients undergoing craniotomy. The Th1/Th2 ratio decreased significantly after isoflurane anaesthesia (p = 0.011), while it did not change after propofol anaesthesia. The ratio was significantly lower with isoflurane than propofol (p = 0.009). Propofol anaesthesia attenuated the surgical stress-induced adverse immune response better than isoflurane anaesthesia.     

Increase in intraocular pressure is less with propofol than with sevoflurane during laparoscopic surgery in the steep Trendelenburg position

Background

Intraocular pressure is increased during laparoscopic surgeries performed in a steep Trendelenburg position. This study compared the effects of propofol with those of sevoflurane on intraocular pressure in patients undergoing robot-assisted laparoscopic radical prostatectomy in a 30° Trendelenburg position.

Methods

Sixty-six patients were randomly allocated to a maintenance anesthetic consisting of remifentanil and sevoflurane (Sevoflurane Group) or remifentanil and propofol (Propofol Group). Intraocular pressure (IOP) was measured at nine predefined time points, including baseline (T0), five minutes after establishing pneumoperitoneum (T2), 30 min after establishing the Trendelenburg position with pneumoperitoneum (T3), five minutes after returning to the horizontal position (T4), and immediately after tracheal extubation (T6). The primary outcome was the change in intraocular pressure from T0 to T3.

Results

The results of linear mixed model analysis showed that intraocular pressure differed between the two groups (P = 0.0039). At T3, the mean (SD) IOP was greater in the Sevoflurane Group [23.5 (4.3) mmHg] than in the Propofol Group [19.9 (3.8) mmHg] (P = 0.0019). At T2 and T6, IOP was also greater in the Sevoflurane Group than in the Propofol Group (P = 0.038 and P = 0.009, respectively). There was a statistically significant increase in intraocular pressure from baseline to T3 (pneumoperitoneum and steep Trendelenberg) in the Sevoflurane Group [6.0 (5.0) mmHg; P < 0.001] but not in the Propofol Group [2.1 (5.1) mmHg; P = 0.136]. None of the patients experienced ocular complications.

Conclusions

Intraocular pressure increases after pneumoperitoneum and the steep Trendelenburg position are established. This increase is less with propofol than with sevoflurane anesthesia. This trial was registered at ClinicalTrials.gov: NCT01744262.     

Kinetics and extravascular retention of acetated ringer's solution during isoflurane or propofol anesthesia for thyroid surgery

BACKGROUND: In sheep, isoflurane causes extravascular accumulation of infused crystalloid fluid. The current study evaluates whether isoflurane has a greater tendency than propofol to cause extravascular retention in surgical patients. METHODS: Thirty patients undergoing thyroid surgery lasting for 143 +/- 32 min (mean +/- SD) received an intravenous infusion of 25 ml/kg acetated Ringer's solution over 30 min. Anesthesia was randomized to consist of isoflurane or propofol supplemented by fentanyl. The distribution and elimination of the infused fluid was estimated using volume kinetics based on the fractional dilution of blood hemoglobin over 150 min. Extravascular retention of infused fluid was taken as the difference between the model-predicted elimination and the urinary excretion. The sodium and fluid balances were measured. RESULTS: The fractional plasma dilution increased gradually to approximately 30% during the infusion and thereafter remained at 15-20%. Urinary excretion averaged 11% of the infused volume. Mean arterial pressure was 10 mmHg lower in the isoflurane group (P < 0.001). The excess fluid volumes in the central and peripheral functional body fluid spaces were virtually identical in the groups. The sum of water losses by evaporation and extravascular fluid retention amounted to 2.0 +/- 2.5 ml/min for isoflurane and 2.2 +/- 2.1 ml/min for propofol. The sodium balance refuted that major fluid shifts occurred between the extracellular and intracellular spaces. CONCLUSIONS: The amount of evaporation and extravascular retention of fluid was small during thyroid surgery, irrespective of whether anesthesia was maintained by isoflurane or propofol.     

Effects of desflurane and isoflurane on intestinal tissue oxygen pressure during colorectal surgery

Volatile anaesthetics differ in the effects they have on splanchnic haemodynamics and oxygenation. The aim of this study was to evaluate the effects of desflurane and isoflurane as part of a balanced anaesthetic technique on intestinal tissue oxygenation during colorectal surgery. Data were analysed from 44 patients randomly assigned to receive either desflurane (desflurane group, n = 20), or isoflurane (isoflurane group, n = 24) for inhalational anaesthesia. Tissue oxygen pressure (P(tiss)O2) was measured on the serosal side of the large intestine prior to colonic resection (T1) and following the completion of the bowel anastomosis (T2). In addition, haemodynamic and oxygenation parameters were assessed. No difference in mean P(tiss)O2 was observed between the groups at T1 [desflurane group: 8.1 (2.9) kPa vs. isoflurane group: 7.7 (2.7) kPa]. Following completion of the anastomosis (T2) mean P(tiss)O2 was higher in the isoflurane group [9.6 (2.9) kPa] than the desflurane group [7.7 (2.4) kPa, p = 0.025]. During surgery no difference between the groups could be observed with regard to haemodynamics and global oxygenation parameters. The lack of a difference between the groups in P(tiss)O2 before resection of the colon suggests that, under normal conditions, desflurane and isoflurane have comparable effects on intestinal blood flow and oxygenation. However, following local ischaemia, the reactive hyperaemia seems to be better preserved during isoflurane anaesthesia indicated by a local increase in P(tiss)O2blank(p = 0.013) following completion of the bowel anastomosis.     

Comparison of the effects of isoflurane and halothane on intraocular pressure

Intraocular pressure (IOP) was measured in four groups of patients receiving isoflurane or halothane in consecutively increasing or decreasing concentrations (1.0, 2.0 and 3.0 MAC in 70% nitrous oxide). IOP decreased significantly in all groups irrespective of whether the higher or the lower concentration of the volatile agent was used first. There were no further significant changes in IOP whether the concentrations were increased or decreased, suggesting no dose-relation. Maximum reductions in IOP were slightly greater in those receiving the higher concentrations of the volatile agents first (64 and 66% with isoflurane and halothane, respectively) in comparison to those receiving the lower concentrations first (54 and 46%, respectively).     

丙泊酚或异氟醚用于妇科腹腔镜手术时脑氧供需平衡的变化

目的 探讨丙泊酚或异氟醚麻醉下头低位气腹期间脑氧供需平衡及能景代谢的改变.方法 24例ASA Ⅰ或Ⅱ级妇科腹腔镜手术患者,随机均分为丙泊酚组和异氟醚组.两组均在局麻下行颈内静脉逆行穿刺置管达颈静脉球,行桡动脉置管.分别以丙泊酚和异氟醚麻醉诱导及维持,术中维持通气条件不变(潮气量7 ml/kg,频率 14次/分).记录麻醉前(T1)、气腹前(T2)、气腹10 min(T3),20 min(T4)及60 min(T5)时桡动脉及颈I静脉球血气、血糖、乳酸以及呼气二氧化碳分压(PETCO2)等,计算脑葡萄摄取(Da-jglu)、动静脉氧含量差(Da-Jo2)及颈静脉球乳酸含量(Jlac)等.结果 T3～T5时两组颈静脉球血氧饱和度(S1O2)、PETCO2较T2时显著升高(P<0.05或P<0.01);Da-Jo2均显著降低(P<0.05或P<0.01);而Da-jglu及Jlac差异无统计学意义.T2～T5时丙泊酚组S1O2显著低于异氟醚组,T2、T4时Da-Jo2高于异氟醚绀(P<0.05).结论 丙泊酚或异氟醚麻醉下头低位气腹期间脑氧供大于氧需,异氟醚麻醉下脑过度灌注更明显,但未出现能量代谢障碍.     

Changes in intraocular pressure during cardiac surgery with and without cardiopulmonary bypass

Purpose  

Data on intraocular pressure (IOP) during cardiac surgery with cardiopulmonary bypass (CPB) and anesthetic management are limited. This study was conducted to investigate changes in IOP during cardiac surgery with and without CPB.     

Intraocular pressure variation during colorectal laparoscopic surgery: standard pneumoperitoneum leads to reversible elevation in intraocular pressure

Background

The potential effects of laparoscopic surgery on intra- and postoperative intraocular pressure (IOP) are not completely understood. Although prior studies have reported that pneumoperitoneum may increase IOP, it is not clear whether this increase is related to the effects of pneumoperitoneum or to the patient’s position, such as the Trendelenburg position. This study aimed to evaluate the potential fluctuations of IOP during colorectal laparoscopic surgery in two groups of patients: those with and those without Trendelenburg positioning.

Methods

For this prospective study 45- to 85-year-old patients undergoing laparoscopic colorectal surgery were enrolled after a thorough ophthalmologic assessment. The study protocol included measurement of IOP at eight different time points (before, during, and after surgery) using a contact tonometer in both eyes.

Results

The study enrolled 29 patients: 17 (58.6 %) with Trendelenburg position placement during surgery and 12 (41.4 %) without Trendelenburg positioning. The two groups did not differ in terms of gender, age, body mass index (BMI), American Society of Anesthesiology (ASA) class, or operative time. In all the patients, pneumoperitoneum induction led to a mild rise in IOP, averaging 4.1 mmHg. The patients with Trendelenburg positioning showed a greater increase than the patients without it (5.05 vs 4.23 mmHg at 45 min; p = 0.179), but IOP evaluation 48 h after surgery showed no substantial differences between the two groups. Among the 29 patients, 17 (58.6 %) showed an increase in IOP of 5 mmHg or more during surgery. A greater percentage of the patients who underwent Trendelenburg positioning showed an IOP increase of 5 mmHg or more (76.5 vs 33.3 %; p = 0.020). At the multivariate analysis, no potential predictors of increased IOP during surgery was identified.

Conclusions

Standard pneumoperitoneum (≤14 mmHg) led to mild and reversible IOP increases. A trend was observed toward a greater IOP increase in patients with Trendelenburg positioning. Thus, the patient’s position during surgery may represent a stronger risk factor for IOP increase than pneumoperitoneum-related intraabdominal pressure.