bluuebunny/crossref_metadata_2025 huggingface dataset:
Light‐guided intubation via the intubating laryngeal mask using a prototype illuminated flexible catheter
Authors: Dimitriou V. , Voyagis G. S.
Published: March 2003

Background: The transillumination of the soft tissues of the neck using lighted stylets has been used as an aid for tracheal intubation. We evaluated the efficacy and safety of a prototype illuminated flexible catheter to facilitate light‐guided intubation through the intubating laryngeal mask.

Methods: The illuminated flexible catheter consists of a completely flexible thin plastic catheter with a bulb attached to its distal end. The device was placed into a silicone tracheal tube in such a way that the bulb was adjusted at the distal end of the tracheal tube. The tracheal tube preloaded with the device was inserted through the intubating laryngeal mask and, by observing the glow on the neck, was advanced into the trachea. We report our experience with light‐guided intubation through the intubating laryngeal mask in 400 ASA grade 1–3 patients undergoing general anaesthesia.

Results: The intubating laryngeal mask was inserted successfully in all patients. The overall intubating success rate was 99.8% (399/400); in 367 (91.8%) cases at the first attempt, in 28 (7%) at the second, in 4 (1%) at the third and in one case (0.2%) at the fifth attempt. There were 27 patients with potentially difficult airways. All these cases were intubated successfully; in 23 of 27 (85.2%) at the first attempt, in 3 of 27 (11.1%) at the second and one of 27 patients (3.7%) at the third attempt.

Conclusion: We conclude that the use of the illuminated flexible catheter facilitates the intubation through the intubating laryngeal mask. The suggested light‐guided intubating method proved to be a simple, safe and effective technique.
Two cases of reiterated Horner’s syndrome after lumbar epidural block
Authors: Høgagarð J. T. , Djurhuus H.
Published: March 2003

We describe two young men with low back pain, who were given repeat lumbar epidural blocks for treatment of pain. They both developed reiterated unilateral Horner’s syndrome. Computer tomography and myelography of the lumbar spine prior to the intervention showed signs of suspect disc herniation and sequelae after previous surgery.
Epidural abscess after epidural catheter for pain release during pancreatitis
Authors: Heller A. R. , Ragaller M. , Koch T.
Published: March 2003

Background: Despite knowledge about compromised host defence in the course of diabetes mellitus and pancreatitis, epidural analgesia (EA) is recommended for pain management during pancreatitis.

Case report:

We present the case of a diabetic patient with pancreatitis who developed an epidural abscess after 3 days with an epidural catheter. Natural killer and T‐helper cell counts were distinctively reduced in the absence of HIV serology. Furthermore, a synthesis failure of the liver was observed and evidenced by low cholinesterase, low whole protein fraction and low antithrombin III in the peripheral blood.

Conclusion: We suggest that the combination of pancreatitis, diabetes and compromised immunity might be a contraindication to epidural analgesia.
Efficacy of intrathecal neostigmine for the relief of postinguinal herniorrhaphy pain
Authors: Tan P.‐H. , Kuo J.‐H. , Liu K. , Hung C.‐C. , Tsai T.‐C. , Deng T.‐Y.
Published: March 2003

Background: Intrathecal administration of various doses of neostigmine has been reported to produce analgesia without neurotoxicity in both animal and human studies. The present study was undertaken to evaluate the efficacy and safety of intrathecal neostigmine for the relief of pain for patients having undergone inguinal herniorrhaphy surgery.

Methods: Sixty men scheduled for elective inguinal herniorrhaphy with spinal anaesthesia were randomly allocated to three groups: group I (n=20) received intrathecal (IT) tetracaine 15 mg, group II (n=20) received IT tetracaine 15 mg+ neostigmine 50 μg, and group III (n=20) received IT tetracaine 15 mg+neostigmine 100 μg. The onset of anaesthesia, duration of analgesia, time to use of first rescue analgesics, the overall 24‐h VAS pain scores and the incidence of adverse effects were recorded for 24 h postdrug administration.

Results: Onset of anaesthesia (time to T6 sensory block) was significantly faster for group II and III patients compared with group I patients. Motor block (time to lift leg) was greatly prolonged for group III patients, with an average of 6.4 h, compared with 4.1 h for group II patients. Group III patients also showed a later onset of postsurgical pain, lower overall 24‐h VAS pain score and prolonged time to first rescue analgesics than did group II patients. There was a significantly greater incidence of adverse effects associated with IT neostigmine, especially nausea and vomiting.

Conclusion: Our study showed that intrathecal neostigmine at 50 μg or 100 μg enhanced the onset of tetracaine anaesthesia and provided analgesia lasting for 6–9 h, although increased incidences of prolonged motor blockade and nausea or vomiting were noted (Note).
Epidural infusion of bupivacaine and fentanyl reduces perioperative myocardial ischaemia in elderly patients with hip fracture – a randomized controlled trial
Authors: Scheinin H. , Virtanen T. , Kentala E. , Uotila P. , Laitio T. , Hartiala J. , Heikkilä H. , Sariola‐Heinonen K. , Pullisaar O. , Yli‐Mäyry S. , Jalonen J.
Published: March 2003

Background: Perioperative myocardial ischaemia is an important risk factor for cardiac morbidity and mortality after noncardiac surgery. The impact of analgesic management on the incidence and severity of cardiac ischemia was studied in 77 elderly patients undergoing surgical treatment of traumatic hip fracture.

Methods: After hospital admission and written consent, patients were randomised to conventional analgesic regimen (intramuscular oxycodone, OPI group) or continuous epidural infusion of bupivacaine/fentanyl (EPI group). The analgesic regimens were started preoperatively. Patients were operated under spinal anaesthesia and the treatments were continued three days postoperatively. ECG was continuously recorded. ST segment depression of ≥0.1 mV or elevation of ≥0.2 mV lasting ≥1 min were considered as ischaemic episodes. Nocturnal arterial oxygen saturation (SaO2) was recorded perioperatively, and subjective pain was assessed every morning using a visual analogue scale (VAS).

Results: Fifty‐nine (OPI 30, EPI 29) patients were evaluable for efficacy. Thirteen patients (43%) in the OPI and 12 patients (41%) in the EPI group had ischaemic episodes (NS). However, significantly more patients in the OPI group had ischaemic episodes during the surgery (8 vs. 0 in the EPI group, P=0.005). The median (quartal deviation) total ischaemic burden (i.e. integral of ST‐change vs. time) in patients with ischaemic episodes was ten times larger in the OPI group (340 [342] mm  ·  min) compared with the EPI group (30 [36] mm  ·  min) (P=0.002). There were no significant differences between the groups in average heart rates or in heart rates at the start of ischaemic episodes or in maximal heart rates during the attacks. Average nocturnal SaO2 was similar in the two groups and there were no differences in the number of hypoxaemic (SaO2<90%) episodes. Preoperatively there were no differences in subjective pain, but postoperative and average perioperative VAS scores for pain were almost 40% lower in the EPI group (P=0.006). Perioperative myocardial infarctions were not detected.

Conclusions: Continuous epidural bupivacaine/fentanyl analgesic regimen, started preoperatively, reduces the amount of myocardial ischaemia in elderly patients with hip fracture.
Selective and segmentally restricted antinociception induced by MPV‐2426, a novel alpha‐2‐adrenoceptor agonist, following intrathecal administration in the rat
Authors: Onttonen T. , Kalmari J. , Pertovaara A.
Published: March 2003

Background: MPV‐2426 (radolmidine) is a novel alpha‐2‐adrenoceptor agonist developed for spinal pain therapy. In the present study we determined the segmental distribution and selectivity of the antinociceptive effect induced by MPV‐2426 following i.t. administration in rats.

Methods: The experiments were performed in lightly anesthetized rats with an i.t. catheter for administration of drugs into the lumbar spinal cord level. To determine segmental distribution of antinociception, the withdrawal latency of the tail and forepaw from a hot water bath was measured. To determine selectivity of reflex modulation, the effect of i.t. MPV‐2426 on the innocuous H‐reflex was determined.

Results: In the hot water immersion test MPV‐2426 produced a dose‐dependent (0.3–3.0 μg) prolongation of tail withdrawal latency whereas the effect on forepaw withdrawal latency was short of significance. Dexmedetomidine, the reference alpha‐2‐adrenoceptor agonist, produced a significant dose‐related prolongation of both the tail and the forepaw withdrawal (0.3 and 1.0 μg). MPV‐2426 (1.0 and 3.0 μg) produced no significant change in the amplitude of the H‐reflex or M‐response induced by electrical stimulation of the tibial nerve, nor any change in the modulation of the H‐reflex amplitude induced by conditioning sural nerve stimulation. The antinociception induced by MPV‐2426 was completely reversed by atipamezole (1 mg/kg s.c.), an alpha‐2‐adrenoceptor antagonist.

Conclusion: MPV‐2426 produces a selective and segmentally more restricted antinociceptive effect than dexmedetomidine following i.t. administration. The antinoception induced by MPV‐2426 is due to action on spinal alpha‐2‐adrenoceptors.
Effects of alpha adrenoreceptor antagonists, prazosin and yohimbine, on intrathecal lidocaine‐induced antinociception in mice
Authors: Uchihashi Y. , Kamei M. , Fukuda I. , Nakai T. , Karasawa F. , Satoh T.
Published: March 2003

Background: The precise mechanisms involved in the spinal analgesic effect of lidocaine are not yet clear. We previously found that lidocaine releases noradrenaline, a modulator of nociception, in rat spinal cord. Here, we attempted to clarify whether or not the noradrenaline release contributes to spinal analgesia by lidocaine.

Methods: The effects of intrathecal injections of the alpha adrenoreceptor antagonists, prazosin (0.01–0.3 nmol) and yohimbine (0.1–3 nmol), on intrathecal 2% lidocaine were assessed using the tail‐flick (TF) test in mice.

Results: Lidocaine significantly increased the TF latency for 15 min. Prazosin (0.03, 0.1 or 0.3 nmol) and yohimbine (0.3, 1.0 or 3.0 nmol) significantly reduced the lidocaine‐induced increase of the TF latency 10 min after injection, although both drugs showed a ceiling effect.

Conclusion: These results suggest that stimulation of the noradrenergic systems plays an important role in spinal analgesia by lidocaine.
Effects of oxygen and nitric oxide inhalation in a porcine model of recurrent microembolism
Authors: Weimann J. , Zink W. , Gebhard M. M. , Gries A. , Martin E. , Motsch J.
Published: March 2003

Background: Inhalation of nitric oxide (iNO) has been proposed for the treatment of acute pulmonary embolism. The present study evaluates the effects of oxygen (O2) and nitric oxide inhalation in a porcine model of sustained pulmonary hypertension induced by recurrent pulmonary microembolism.

Methods: Twelve pigs were embolized under general anesthesia with 300‐μm microspheres intravenously three times over a period of seven weeks. Five pigs served as untreated controls. Hemodynamic and gas exchange responses to 100% oxygen and 40 ppm NO inhalation, and their combination (O2+iNO) were measured seven days after the last embolization.

Results: Recurrent microembolism caused sustained pulmonary hypertension (pulmonary vascular resistance index; PVRI 408±57 dyn · s · cm−5 · m−2) as compared to the control group (PVRI 143±20 dyn · s · cm−5 · m−2; P<0.05). PVRI was significantly reduced by O2, iNO, and O2+iNO inhalation by 29±3, 28±4, and 32±3%, respectively.

Conclusion: We conclude that both O2 and iNO are selective pulmonary vasodilators in a porcine model of sustained pulmonary hypertension following recurrent pulmonary microembolism and, therefore, may be useful in the treatment not only in the acute phase of pulmonary embolism but also later in the time course of the disease.
Electrical stimulation of the vestibular system prevents postoperative nausea and vomiting
Authors: Pusch F. , Freitag H. , Goll V. , Wildling E. , Hoerauf K. , Obwegeser R. , Weinstabl C.
Published: March 2003

Background: Electrical stimulation of the vestibular system may prevent nausea and vomiting. We studied the influence of transcutaneous impulse stimulation in prevention of postoperative nausea and vomiting (PONV) following gynaecological surgery.

Methods: In this randomised study 70 women undergoing elective gynaecological surgery under general anaesthesia were assigned to receive either the activated (stimulation group) or the inactivated (non‐stimulation group) impulse stimulator. The stimulator comprises the stimulator itself, two negative electrodes on a headset applied over both mastoid processes and a nuchal positive electrode. The device yielded a pulse frequency of 5 Hz direct current, individually adjustable between 0.5 and 4 mA. A trapezoid stimulation of 50 ms was applied. Nausea, vomiting, dizziness and the amount of antiemetic drugs used were assessed during the first 4 h postoperatively.

Results: Lower postoperative nausea scores with a lower incidence of vomiting and postoperative dizziness were found in the stimulation group. A lower amount of antiemetic drugs was needed in the stimulation group when compared to the non‐stimulation group (P<0.01 between groups).

Conclusion: This study suggests that electrical stimulation of the vestibular system may be useful in prevention of PONV.
The effect of desflurane on liver function markers in infants and children
Authors: Wissing H. , Kuhn I.
Published: March 2003

Background: In an open‐labelled clinical trial, the effect of desflurane anaesthesia on liver function markers in paediatric patients was monitored.

Methods: Fifty infants and children, 37 male, scheduled for elective cleft plate surgery were included in the study. Median age was 0.57 (0.25–5.45) years (range), mean desflurane exposure was 2.29±0.75 MAC‐h. Function markers were determined within 24 h prior to and within 24–48 h after anaesthesia. Complete data sets were available for total bilirubin 29, aspartate aminotransferase (ASAT) 36, alanine aminotransferase (ALAT) 35, and for alkaline phosphatase (AP) 28. Pre‐ and postanaesthetic function tests were compared by means of Wilcoxon's matched‐pairs test.

Results: Only for AP could a statistically significant reduction of the postanaesthetic values be observed, while the other parameters showed no significant changes. Postanaesthetic ASAT and ALAT were clearly reduced in three children who had unspecific highly elevated preanaesthetic values. After the study, this observation could be repeated in at least one child, who received a further anaesthesia with desflurane within 3 months.

Conclusion: The data suggest that desflurane does not affect excretory or structural liver integrity in infants and children.
Pharmacokinetic studies of neuromuscular blocking agents: Good Clinical Research Practice (GCRP)
Authors: Viby‐Mogensen J. , Østergaard D. , Donati F. , Fisher D. , Hunter J. , Kampmann J. P. , Kopman A. , Proost J. H. , Rasmussen S. N. , Skovgaard L. T. , Varin F. , Wright P. M. C.
Published: March 2003

In September 1997, an international consensus conference on standardization of studies of neuromuscular blocking agents was held in Copenhagen, Denmark. Based on the conference, a set of guidelines for good clinical research practice (GCRP) in pharmacokinetic studies of neuromuscular blocking agents is presented. Guidelines include: design of the study; relevant patient groups to investigate; test drug administration, sampling and analysis; pharmacokinetic analysis; pharmacokinetic/pharmacodynamic modeling; population pharmacokinetics; statistics; and presentation of pharmacokinetic data. The guidelines are intended to aid those working in this research area; it is hoped that they will assist researchers, editors of scientific papers, and pharmaceutical companies in improving the quality of pharmacokinetic studies.
Improved cerebral blood supply and oxygenation by aortic balloon occlusion combined with intra‐aortic vasopressin administration during experimental cardiopulmonary resuscitation
Authors: Nozari A. , Rubertsson S. , Wiklund L.
Published: March 2003

Background: Intravenous administration of vasopressin during cardiopulmonary resuscitation (CPR) has been shown to improve myocardial and cerebral blood flow. Aortic balloon occlusion during CPR may also augment myocardial and cerebral blood flow and can be used as a central route for the administration of resuscitative drugs. We hypothesized that, as compared with intravenously administered vasopressin, the administration of this drug above the site of an aortic balloon occlusion would result in a greater increase in cerebral perfusion and oxygenation during CPR and after restoration of spontaneous circulation (ROSC).

Methods: Twenty piglets were subjected to 5 min of ventricular fibrillation followed by 8 min of closed‐chest CPR and were treated with 0.4 U kg−1 boluses of vasopressin intravenously (the IV‐vasopressin group with sham aortic balloon) or above the site for an aortic balloon occlusion (the balloon‐vasopressin group). The aortic balloon catheter was inflated in the latter group 1 min after commencement of CPR and was deflated within 1 min after ROSC. Systemic blood pressures, cerebral cortical blood flow, cerebral tissue pH and PCO2 were monitored continuously and the cerebral oxygen extraction ratio was calculated.

Results: During CPR, arterial blood pressure and cerebral perfusion pressure were greater in the balloon‐vasopressin group, as compared with the IV‐vasopressin group. These pressures did not differ between the groups after ROSC. Cerebral cortical blood flow was not significantly greater in the balloon‐vasopressin group during CPR, whereas significantly higher cortical blood flow levels were recorded after ROSC. Cerebral tissue pH decreased in the IV‐vasopressin group during the post‐resuscitation hypoperfusion period. In contrast, decreasing pressures during the hypoperfusion period did not result in increasing tissue acidosis in the balloon‐vasopressin group.

Conclusions: During CPR, intra‐aortic vasopressin combined with aortic balloon occlusion resulted in significantly greater perfusion pressures but not in greater cerebral cortical blood flow. After ROSC, however, a greater increase in cortical blood flow was recorded in the balloon‐vasopressin group, even though the aortic balloon was deflated and perfusion pressures did not differ between the groups. This suggests that vasopressin predominantly gives vasoconstrictive effects on cerebral cortical vessels during CPR, but results in cerebral cortical vasodilatation after ROSC.
Effects of remifentanil on neutrophil adhesion, transmigration, and intercellular adhesion molecule expression
Authors: Hofbauer R. , Frass M. , Gmeiner B. , Sandor N. , Schumann R. , Wagner O. , Kaye A. D.
Published: March 2003

Background: Anaesthetic drugs are used for pain therapy and anaesthesia. Neutrophils play a significant role during the process of inflammation. The aim of the current study was to investigate the effects of remifentanil and fentanyl on neutrophil migration through endothelial cell monolayers, and on adhesion molecule expression.

Methods: After isolation of polymorphonuclear neutrophils (PMNL) we used a currently described migration assay. PMNL and/or endothelial cell monolayers (ECM) were pre‐treated with remifentanil using clinically relevant, as well as higher and lower concentrations or relevant concentrations of fentanyl.

Results: Concentrations of remifentanil (50 ng/mL) similar to the relevant plasma concentration were able to inhibit PMNL migration through ECM significantly (migration compared to the control 82±7% SD; P<0.05), when both cell types were treated with the synthetic narcotic remifentanil. Fentanyl (30 ng/mL) showed a stronger inhibitory effect (migration compared to the control 67±9.2%; P<0.05). Endothelial cell adhesion molecule expression was reduced after either remifentanil or fentanyl.

Conclusion: The results of the present investigation indicate that remifentanil influences interaction of ECM against human neutrophils. Compared to fentanyl, remifentanil seems to exhibit minor inhibitory effects on neutrophil migration.
Angiotensin II mesenteric and renal vasoregulation: Dissimilar modulatory effects with nitroprusside
Authors: BroomÉ M. , Åneman A. , Haney M. , HÄggmark S. , Johansson G. , Biber B.
Published: March 2003

Background: The role of systemic arterial pressure for the vascular effects of angiotensin II (Ang II) and the interactions between Ang II and perfusion pressure‐dependent local vascular control mechanisms are not well understood. This study addresses these aspects of exogenous Ang II in the mesenteric and renal regional circulations.

Methods: Ang II was infused in incremental doses (0–200 μg/h) in anesthetized instrumented pigs (n=10). Renal and portal blood flows were measured by perivascular ultrasound. In the second part of the study, sodium nitroprusside (SNP) was infused at doses titrated to keep mean arterial pressure constant, in spite of concurrent Ang II administration.

Results: Powerful dose‐dependent vasoconstrictions by Ang II were found in renal and mesenteric vascular beds (at highest Ang II doses vascular resistances increased by 109% and 88% respectively). Ang II‐induced vasoconstriction was fully inhibited in the mesenteric, but not in the renal circulation, during conditions of constant mean arterial pressures achieved by SNP infusion.

Conclusions: Mesenteric, but not renal, vasoconstriction by Ang II was inhibited by pharmacological maintenance of perfusion pressure. This could reflect differences between these vascular beds as regards the importance of co‐acting myogenic pressure‐dependent vasoconstriction. Alternatively, as the drug chosen for pressure control, sodium nitroprusside, serves as a nitric oxide donor, the relative balance between nitric oxide‐mediated vasodilation and Ang II‐induced vasoconstriction could have regional differences.
Cognitive dysfunction 1–2 years after non‐cardiac surgery in the elderly
Authors: Abildstrom H. , Rasmussen L. S. , Rentowl P. , Hanning C. D. , Rasmussen H. , Kristensen P. A. , Moller J. T. ,   the ISPOCD group
Published: March 2003

Background: Postoperative cognitive dysfunction (POCD) is a well‐recognised complication of cardiac surgery, but evidence of POCD after general surgery has been lacking. We recently showed that POCD was present in 9.9% of elderly patients 3 months after major non‐cardiac surgery. The aim of the present study was to investigate whether POCD persists for 1–2 years after operation.

Methods: A total of 336 elderly patients (median age 69 years, range 60–86) was studied after major surgery under general anesthesia. Psychometric testing was performed before surgery and at a median of 7, 98 and 532 days postoperatively using a neuropsychological test battery with 7 subtests. A control group of 47 non‐hospitalised volunteers of similar age were tested with the test battery at the same intervals.

Results: 1–2 years after surgery, 35 out of 336 patients (10.4%, CI: 7.2–13.7%) had cognitive dysfunction. Three patients had POCD at all three postoperative test sessions (0.9%). From our definition of POCD, there is only a 1:64 000 likelihood that a single subject would have POCD at all three test points by chance. Logistic regression analysis identified age, early POCD, and infection within the first three postoperative months as significant risk factors for long‐term cognitive dysfunction. Five of 47 normal controls fulfilled the criteria for cognitive dysfunction 1–2 years after initial testing (10.6%, CI: 1.8–19.4%), i.e. a similar incidence of age‐related cognitive impairment as among patients.

Conclusion: POCD is a reversible condition in the majority of cases but may persist in approximately 1% of patients.
Does efficacy of seal and fibreoptic view change during anaesthesia with the laryngeal mask airway: A comparison of oxygen and oxygen‐nitrous oxide gas mixtures
Authors: Brimacombe J. , Keller C.
Published: March 2003

Background: We test the hypothesis that oropharyngeal leak pressure (OLP) and fibreoptic position (FP) are stable for the laryngeal mask airway (LMA) during anaesthesia with and without nitrous oxide.

Methods: Forty paralysed anaesthetised patients (ASA 1–2, aged 18–80) were randomly allocated to receive 100% oxygen (O2 group) or 33% oxygen in nitrous oxide (O2‐N2O group) for maintenance. In vivo intracuff pressure (CP) using a size 5 LMA was adjusted to 60 cm H2O. OLP, FP and CP were measured every 5 min for 30 min.

Results: CP was higher in the O2‐N2O group than the O2 group, other than at time zero (all: P<0.0001). CP increased every 5 min in the O2‐N2O group (all: P<0.0001), but not in the O2 group. There were no differences in OLP and FP between groups at any time. There were no significant changes in OLP or FP with time within each group. There were no changes in OLP greater than 1.5 cm H2O and no change in FP for any patient.

Conclusion: We conclude that OLP and FP are stable for the LMA during anaesthesia lasting 30 min with or without nitrous oxide.
No genotoxic effect of propofol in Chinese hamster ovary cells: Analysis by sister chromatid exchanges
Authors: Tomioka S. , Nakajo N.
Published: March 2003

Background: In spite of its high placental transfer, propofol is frequently used in general anesthesia and sedation during obstetric and gynecological surgery such as in vitro fertilization. This study investigated whether or not propofol has a genotoxic potential by the sister chromatid exchange assay in vitro.

Methods: Sister chromatid exchanges induced after exposure to propofol were measured in Chinese hamster ovary cells with and without metabolic activation. After propofol (0.2–20 μg ml−1) diluted dimethyl sulfoxide was applied for 2 h with or without S9 mix, the cells having been incubated for two metaphases (34 h) in the presence of 5′‐bromo‐2‐deoxyuridine. N‐nitrosodimethylamine and mitomycin C were used as positive controls with and without metabolic activation. The chromosomes were stained with the fluorescence plus Giemsa method, and then sister chromatid exchanges in 50 cells were counted for each concentration.

Results: Although increasing concentrations of propofol inhibited cell proliferation, no concentrations of propofol used in this study increased the sister chromatid exchange values, with and without metabolic activation.

Conclusion: It was concluded that there was no indication, from the sister chromatid exchange assay in mammalian cells, of a genotoxic effect of propofol and its metabolites.
Are electrocardiogram electrodes acceptable for electroencephalogram bispectral index monitoring?
Authors: Seitsonen E. , Yli‐Hankala A. , Korttila K.
Published: March 2003

Background: The monitoring of electroencephalogram bispectral index (EEG‐BIS) during anaesthesia reduces anaesthetic use and improves recovery. However, it also increases the direct costs of anaesthesia due to the need for special EEG electrodes. In the present study we tested the feasibility of less expensive electrocardiogram (ECG) electrodes for EEG‐BIS monitoring.

Methods: In the first part of the study we compared skin‐electrode impedances when EEG electrodes were used after alcohol swab pretreatment of skin to impedances when ECG electrodes were used after alcohol swab pretreatment with or without skin abrasion paste. In the second part of the study we evaluated the difference in parallel BIS values collected with two BIS monitors, using either ECG electrodes or EEG electrodes. In the third part of the study we compared parallel BIS values collected with two sets of EEG electrodes.

Results: Skin pretreatment with abrasion paste led to lower impedances with ECG electrodes than did alcohol swab pretreatment of skin with EEG electrodes. When the skin was pretreated with alcohol swab, higher impedances were measured with ECG electrodes than with EEG electrodes. In most patients, BIS values collected with ECG electrodes were also higher than those collected with adhesive EEG electrodes. The difference between parallel BIS values collected with two sets of adhesive EEG electrodes was smaller than the difference between BIS values collected with ECG and EEG electrode sets.

Conclusion: Low skin‐electrode impedances indicating reliable skin‐electrode contact can be ensured with inexpensive pregelled ECG electrodes only if the skin is carefully prepared with both abrasion paste and alcohol. When only alcohol pretreatment of skin is used, the BIS values collected with EEG electrodes and ECG electrodes are not equal. EEG‐BIS monitoring with pregelled ECG electrodes is recommended only if skin is prepared with abrasion paste before attaching the electrodes.
A survey of tracheal intubation difficulty in the operating room: a prospective observational study
Authors: Adnet F. , Racine S. X. , Borron S. W. , Clemessy J. L. , Fournier J. L. , Lapostolle F. , Cupa M.
Published: March 2003

Background: The purpose of this study is to describe all degrees of endotracheal intubation difficulty among patients attended by eight anesthesiologists during routine surgery over a six‐month period. Airway characteristics were routinely assessed preoperatively, according to the anesthesiologists’ usual practice.

Methods: Difficult tracheal intubation was evaluated by the Intubation Difficulty Scale (IDS), a quantitative score based on seven variables. An IDS value of 0 is consistent with a procedure without difficulty, and an IDS > 5 with a procedure involving moderate to major difficulty.

Results: For 1171 patients undergoing tracheal intubation, IDS was 0 in 55%, and greater than 5 in 8% of cases. External laryngeal pressure, repositioning the patient and added use of a stylet were the most frequent methods chosen to facilitate tracheal intubation.

Conclusion: There was a high incidence (37%) of minor difficulties encountered during routine surgery.
Airway pressure release ventilation and prone positioning in severe acute respiratory distress syndrome
Authors: Varpula T. , Pettilä V. , Nieminen H. , Takkunen O.
Published: March 2003

Background: Implementation of lung protective strategy in the treatment of severe Acute Respiratory Distress Syndrome (ARDS) has been reported to be associated with improved outcome. To fulfil this approach, sedation, neuromuscular blocking agents and full mechanical ventilatory support are often used in critical failure of gas exchange.

Case report:

We present a patient who developed multiple organ failure, including severe ARDS, after severe skin injuries and septic shock. Ventilatory strategy consisted of lung protective approach, permissive hypercapnia and prone positioning. Airway pressure release ventilation (APRV) with the patient’s superimposed spontaneous breathing was implemented and maintained, also during prone episodes. Improvement of gas exhange occurred after application of combined use of APRV and prone positioning.

Conclusion: APRV and maintenance of patients’ spontaneous ventilation is feasible during prone positioning, and this approach may have beneficial synergistic effects on gas exhange in patients with severe acute lung injury.
End‐tidal to arterial oxygen tension difference as an oxygenation index
Authors: Bengtsson J. , Bake B. , Johansson Å. , Bengtson J. P.
Published: March 2003

Background: “Ideal” alveolar oxygen tension (PAO2) is a calculated entity and the alveolar‐arterial oxygen tension difference (PA‐aO2) is used to evaluate gas exchange function of the lungs. Accurate calculations of PAO2 necessitate measurements of the respiratory exchange ratio (RER), which is less frequently done, and most often approximations are made. The measured end‐tidal oxygen tension (PETO2) is a reflection of the alveolar oxygen tension. The aim was to study the relationship between PAO2 and PETO2, and to see whether the end‐tidal to arterial oxygen tension difference (PET‐aO2) could give the same information about lung function as PA‐aO2.

Methods: Twenty patients admitted for cardio‐pulmonary exercise tests were studied. They bicycled for 4 min at each work load until maximum work load was reached. Arterial blood gases were analysed before, after 4 min at each work load, at maximum work load and after 2 min of recovery. A metabolic computer measured mixed expired gas concentrations. End‐tidal gas concentrations were measured with a side stream gas analyser.

Results: We measured major increases in oxygen uptake, carbon dioxide elimination and RER. PAO2 and PETO2 increased at maximum exercise and during recovery. PAO2 and PETO2 were closely correlated during the study, through great changes in oxygen uptake and RER (r=0.88). When correction was made for wet gas the median difference was 0.12 kPa.

Conclusions: At ambient air (FIO2=0.21), PET‐aO2 as a respiratory index may give equivalent information to PA‐aO2, without the need for measurements of mixed expired gas tensions or the hazard of an assumed RER.
Life‐threatening upper airway obstruction in a child caused by retropharyngeal emphysema
Authors: Skogvoll E. , Grammeltvedt A.‐T. , Aadahl P. , Mostad U. , Slørdahl S.
Published: March 2003

A 21/2‐year‐old boy with acute obstructive lung disease from adenovirus infection developed cough‐induced paroxysms of intense dyspnoea leading to respiratory failure. Chest x‐ray and fluoroscopy demonstrated retropharyngeal air occluding the airway. The clinical management of this and similar air‐leak problems is discussed.
Effects of olprinone, a new phosphodiesterase inhibitor, on gastric intramucosal acidosis and systemic inflammatory responses following hypothermic cardiopulmonary bypass
Authors: Yamaura K. , Akiyoshi K. , Irita K. , Taniyama T. , Takahashi S.
Published: March 2003

Background: Phosphodiesterase (PDE) III inhibitors have both an inotropic and a peripheral vasodilatory effect, and also inhibit the activation of macrophages. Thus a newly developed PDE III inhibitor, olprinone, could modify gastric intramucosal pH (pHi), systemic oxygen consumption, and systemic inflammatory responses in patients undergoing cardiac surgery with cardiopulmonary bypass (CPB).

Methods: We studied 23 patients. In 15 patients, olprinone (0.1 or 0.2 μg · kg−1 · min−1) was administered from the commencement of CPB until their admission to the ICU. The other 8 patients received placebo. The pHi and regional CO2 tension (PrCO2) were assessed by a capnometric air tonometry. Systemic inflammatory responses were evaluated by serum interleukin‐6 (IL‐6), IL‐10, and leucocyte counts.

Results: The pHi and PCO2‐gap, the difference between PrCO2 and arterial CO2 tension (PaCO2), showed a transient decrease and an increase after CPB, respectively. Although olprinone did not affect pHi, olprinone at 0.2 μg · kg−1 · min−1 significantly lessened post‐CPB increase in PCO2‐gap. Olprinone at 0.2 μg · kg−1 · min−1 significantly increased IL‐10 and reduced the extent of leucocytosis, while it did not affect IL‐6 levels. At the same dosage, olprinone also lessened the surge in systemic oxygen uptake index (V˙O2) and augmented the increase in mixed oxygen saturation (Sv¯O2) both of which occurred after CPB. At 0.1 μg · kg−1 · min−1, however, olprinone did not show any significant effect.

Conclusion: Our results suggest that olprinone at 0.2 μg · kg−1 · min−1 suppresses gastric intramucosal acidosis and systemic inflammation following CPB.
Total knee replacement: a comparison of ropivacaine and bupivacaine in combined femoral and sciatic block
Authors: Mcnamee D. A. , Convery P. N. , Milligan K. R.
Published: March 2003

Background: Femoral and sciatic nerve block may improve post‐operative analgesia following total knee replacement.

Objectives:

To compare the post‐operative analgesia following primary total knee replacement provided by spinal anaesthesia alone or in combination with femoral and sciatic nerve block with bupivacaine or ropivacaine.

Methods: Seventy‐five patients were randomised into one of three groups: spinal anaesthesia only; spinal anaesthesia and combined femoral and sciatic nerve block with 1 mg · kg−1 bupivacaine 7.5 mg · ml−1 to each nerve; spinal anaesthesia and combined femoral and sciatic nerve block with 1 mg · kg−1 ropivacaine 7.5 mg · ml−1 to each nerve.

Results: The mean (SD) time to first morphine request was significantly prolonged for both groups receiving combined femoral and sciatic block, 912 (489) min for the bupivacaine group and 781 (394) min for the ropivacaine group (P<0.001) compared with 413 (208) min for the group receiving spinal anaesthesia alone. Morphine consumption was significantly reduced in both groups receiving combined femoral and sciatic block. There were no systemic or neurological sequelae in any of the groups.

Conclusions: Femoral and sciatic blockade following intrathecal bupivacaine/diamorphine provided superior analgesia when compared with intrathecal bupivacaine/diamorphine alone. There were no significant clinical differences between the group receiving bupivacaine 7.5 mg · ml−1 and the group receiving ropivacaine 7.5 mg · ml−1.
Computer control versus manual control of systemic hypertension during cardiac surgery
Authors: Hoeksel S. A. A. P. , Blom J. A. , Jansen J. R. C. , Maessen J. G. , Schreuder J. J.
Published: March 2003

Background: We recently demonstrated the feasibility of computer controlled infusion of vasoactive drugs for the control of systemic hypertension during cardiac surgery. The objective of the current study was to investigate the effects of computer controlled blood pressures on hemodynamic stability when compared to conventional manual control.

Method:

Systemic artery blood pressures were managed either by computer (80 patients) or by a well‐trained anesthesiologist (80 patients). The vasodilator drugs sodium nitroprusside and nitroglycerin were used. Hemodynamic stability was determined from the standard deviation of the mean arterial pressure samples and from the percentages of time that arterial pressure was hypertensive or hypotensive.

Results: The average standard deviation of the mean arterial pressure samples was smaller for the computer controlled than for the manually controlled group: 7.5±2.2 (mean±SD) versus 8.9±2.3 mmHg (P<0.0001). The systemic artery pressure was less hypertensive and less hypotensive in the computer controlled than in the manually controlled group: 9.4±5.7 versus 13.1±6.0% (P<0.0001) and 8.0±5.9 versus 11.8±7.4% (P<0.0001), respectively.

Conclusion: We conclude that, compared with manual control, computer control of systemic hypertension significantly improved hemodynamic stability during cardiac surgery.
Intraocular pressure and ropivacaine in peribulbar block: A comparative study with bupivacaine
Authors: Nociti J. R. , Serzedo P. S. M. , Zuccolotto E. B. , Nunes A. M. M. , Ferreira S. B.
Published: March 2003

Background: The aim of this study was to compare the effects on intraocular pressure (IOP) of ropivacaine and bupivacaine in peribulbar block.

Methods: The study involved 40 patients with ASA physical status I, II or III undergoing cataract surgery under peribulbar block. Patients were allocated to two groups according to the local anesthetic used: Group R (n=20), 1.0% ropivacaine and Group B (n=20) 0.75% bupivacaine, both associated with 50 IU · ml−1 hyaluronidase, in peribulbar double injection technique. IOP was measured at four time points: 0=before block (control); 1=1 min after block; 2=5 min after block; 3=15 min after block.

Results: Mean values of IOP (mm Hg) after block were significantly lower in Group R in comparison to Group B: time point 1=13.4±3.2 vs 20.8±4.7; time point 2=10.9±3.7 vs 14.4±3.8; time point 3=7.7±4.0 vs 10.5±3.1. The variation of IOP was different in each group. In Group R, the mean values obtained at the three time points after block were significantly lower than the control; in Group B, the mean value of IOP rose significantly 1 min after block and was lower than control only at time point 3.

Conclusions: Ropivacaine 1.0% associated with hyaluronidase in peribulbar block is better than 0.75% bupivacaine under the same standard conditions for lowering IOP in intraocular surgery. This effect is probably due to relaxation of the extraocular muscles after the block with both anesthetics, and possibly to a smaller intraocular blood volume due to vasoconstriction in the case of ropivacaine.
Effect of preincisional ilioinguinal and iliohypogastric nerve block on postoperative analgesic requirement in day‐surgery patients undergoing herniorrhaphy under spinal anaesthesia
Authors: Toivonen J. , Permi J. , Rosenberg P. H.
Published: March 2003

Background: By choosing spinal anaesthesia instead of general anaesthesia, and by infiltrating the wound area with local anaesthetic the need for postoperative analgesics may be reduced. An ilioinguinal and iliohypogastric nerve block (IINB) in inguinal herniorrhaphy was, therefore, studied in a day surgery setting in combination with a spinal block.

Methods: One hundred ASA I–II adult patients scheduled for inguinal herniorrhaphy were given spinal anaesthesia with hyperbaric 0.5% bupivacaine. In a randomized and blinded fashion half of them received an IINB 5 min before the surgical incision with 10 ml of 0.5% bupivacaine (B‐IINB) and the other half with saline (S‐IINB). All patients received ketoprofen 100 mg i.v. during surgery and another 100 mg 2–3 h postoperatively. The patients were observed for about 6 h in the day surgery unit before discharge.

Results: The results showed that in comparison with the S‐IINB group, significantly fewer patients in the B‐IINB group needed analgesics (P<0.01) and the amount required was also significantly less postoperatively, before discharge (about 6 h postoperatively) (P<0.05). The latency to the need for the first postoperative analgesic was shorter in the S‐IINB patients (P<0.01). At home the VAS scores and the need for analgesics (oral ketoprofen 100 mg) were low with no differences between the groups. No complications occurred.

Conclusion: It is concluded that no long‐term analgesia could be demonstrated by a preincisional IINB performed during spinal anaesthesia in day‐surgery inguinal herniorrhaphy patients. Thus, reduced analgesic requirement was seen only for about 6 h postoperatively.
Distribution of intrathecal catheter positions in rat
Authors: Asato F. , Butler M. , Blomberg H. , Gordh T.
Published: March 2003

Background: Although drug administration through an intrathecal catheter is widely used in the study of spinal pharmacology, the catheter positions in transverse plane that may cause a limited spread of a solution remain unclear. In the first step to clarify this issue, the distribution of the intrathecal catheter position was investigated in rats.

Methods: A polyethylene catheter (PE‐10) was inserted intrathecally 8.5 cm through the atlanto‐occipital membrane, aiming the tip of the catheter to the dorsal surface of the spinal cord. Three or four weeks after the implantation of the catheter, 83 rats were transcardiacally perfused with fixative solution. The catheter positions were investigated longitudinally and transversely by cutting the spinal cord segmentally through the intervertebral disk at different spinal levels.

Results: Seventeen rats were excluded from further data analysis. Transversely, catheters were located in the left lateral subarachnoid space in 23 rats (35%), in the right lateral in 15 (23%), in the dorsal in 22 (33%), and in the ventral in 6 (9%). Longitudinally, catheter position was significantly higher in the ventral group (median, T9) than that in the dorsal group (T11/12) (P<0.01).

Conclusion: Chronic intrathecal catheters were variously located in the rat spinal subarachnoid space in the transverse plane, and lateral subarachnoid placement of the catheter (58%) was frequently observed, whereas dorsal subarachnoid placement occurred in 33%.
Ease of laryngeal passage during fibreoptic intubation: a comparison of three endotracheal tubes
Authors: Barker K. F. , Bolton P. , Cole S. , Coe P. A.
Published: March 2003

Background: The use of a fibreoptic bronchoscope to facilitate endotracheal intubation is well established in modern anaesthetic practice. Difficulty may be encountered when inserting an endotracheal tube over the fibrescope as the bevelled tip can impinge on the vocal cords or epiglottis and impede advancement through the laryngeal inlet. Intavent have recently developed a tapered tip tube for use with their Intubating Laryngeal Mask Airway. A randomised, double‐blind study was performed to compare the ease of railroading three different tubes over a fibrescope placed in the trachea.

Methods: We studied 54 patients presenting for elective dental surgery. General anaesthesia was induced with propofol 2–3 mg/kg, fentanyl 1–1.5 μg/kg, and atracurium 0.5 mg/kg and maintained with oxygen (5 l/min) and isoflurane 1–2%. Nasotracheal fibreoptic intubation was attempted in all patients. In each case the ease of tube advancement over the fibrescope and into the trachea was evaluated by the blinded observer, using the classification system (Grade 0–2) described by Jones et al.

Results/Conclusion:

The Intavent tube was found to be superior for nasotracheal fibreoptic intubation to either the Mallinckrodt reinforced tube (P<0.034) or the Portex Blue Line tube (P<0.004).
Clonidine decreases intraoperative bleeding in middle ear microsurgery
Authors: Marchal J. M. , Gómez‐Luque A. , Martos‐Crespo F. , Sánchez De La Cuesta F. , Martínez‐López M. C. , Delgado‐Martinez A. D.
Published: March 2003

Background: The antihypertensive drug clonidine is a centrally acting α2 agonist useful as a premedicant because of its sedative, anxiolytic, and analgesic properties. We examined the effect of clonidine given as an oral preanesthetic medication in producing a bloodless surgical field in patients undergoing middle ear microsurgery. We also evaluated whether the administration of clonidine would alter the reflex cardiovascular response to laryngoscopy and endotracheal intubation, anesthetic requirement, postoperative pain intensity and consumption of analgesics, and pre‐ and postoperative sedation and anxiety.

Methods: A prospective, randomized, double‐blind clinical trial was performed in 40 patients scheduled for elective middle ear surgery under general anesthesia. Twenty‐one patients received clonidine (300 μg p.o.) 90 min prior to arrival at the operating theater and 19 received placebo (control group). The hemodynamic endpoint of the anesthetic management was maintenance of hypotension for producing a bloodless surgical field. The desired control of the cardiovascular system was attained with isoflurane (inspired concentration increments of 0.25 vol% up to a maximum of 1.5 vol%)±fentanyl (bolus of 1 μg · kg−1)±urapidil (bolus of 0.3 mg · kg−1) as needed. Intraoperative bleeding was assessed on a four‐point scale from 0=no bleeding to 3=abundant bleeding.

Results: There was less bleeding in the clonidine group (mean±SEM) than in the control group (0.75±0.3 vs 1.1±0.4, P<0.05). Patients given clonidine required a mean inspired isoflurane concentration of 0.63±0.1 vol% as compared with 1.01±0.2 vol% in controls (P<0.05). Fentanyl requirements were also significantly lower (57.10 vs 79.42 μg · kg−1, P<0.05). Four clonidine‐treated patients required urapidil to achieve satisfactory hypotension as compared with 11 controls (P<0.05). Clonidine attenuated the associated cardiovascular response following laryngoscopy and intubation, and was more effective than placebo in achieving a satisfactory preoperative sedation and decreasing intensity of postoperative pain. Preoperative anxiety and incidence of adverse events was similar in both groups.

Conclusion: Premedication with clonidine reduced bleeding in middle ear microsurgery, attenuated hyperdynamic response to tracheal intubation, and reduced isoflurane, fentanyl, and urapidil requirements for controlled hypotension.