bluuebunny/crossref_metadata_2025 huggingface dataset:
Is preoperative ketorolac a useful adjunct to regional anesthesia for inguinal herniorrhaphy?
Authors: Ben‐David B. , Baune‐Goldstein U. , Goldik Z. , Gaitini L.
Published: January 2009

Background: Nonsteroidal antiinflammatory drugs (NSAIDs) have become a popular component of analgesia regimens, particularly in combination with narcotics. We questioned whether there might also be a place for their use in conjunction with regional anesthesia and whether there was a preferable route for NSAID administration.

Methods: Ilioinguinal and field blocks were performed pre‐operatively on seventy patients undergoing outpatient inguinal hernia repair. Patients were divided into a control group who received no ketorolac and four study groups who received a preoperative dose of 30 mg ketorolac by one of the following routes: IV, IM, PO, or intrawound (IW). The ketorolac in the IW group was mixed in the syringe with the local anesthetic used for the field block. IV and IM groups also received ketorolac at the time of the preoperative regional anesthesia and the PO group received the dose at least one hour preoperatively. All patients received a similar general anesthetic intraoperatively.

Results: Postoperative pain scores and analgesic requirements were lowest for the IM, IV, and IW groups. Pain scores and analgesic requirements for the PO group were less than for the control group but more than for the other three groups. Analgesic efficacy therefore ranked: IM = IV = IW>PO>Control.

Though no differences were found between groups in the time to discharge from the recovery room, the ease of nursing care paralleled the findings for pain scores and analgesia requirements.

Conclusion: Beyond the analgesia provided by the regional anesthesia of the ilioinguinal and field blocks, the preoperative use of ketorolac further reduced postoperative pain scores and the need for additional postoperative analgesic medication. Comparable outcomes for the IV, IM, and IW groups indicate the lack of any benefit to concentrating the non‐steroidal anti‐inflammatory drug at the wound (IW) or to achieving high blood levels rapidly (IV). In conclusion, ketorolac is a useful supplement to ilioinguinal plus field block regional anesthesia for hernia surgery and is most effective administered parenterally.
Menstrual stage influences postoperative nausea and vomiting following epidural buprenorphine
Authors: Kitamura A. , Kon T. , Kamiyama M. , Ggawa R.
Published: January 2009

Background: Although buprenorphine sometimes causes severe emesis, its relation to the menstrual cycle has not been reported.

Methods: We conducted a prospective study on 68 reproductive‐age women following lower extremity surgery under epidural anesthesia plus buprenorphine, to assess the effect of the day of the menstrual cycle on the incidence of postoperative nausea and vomiting. The patients were divided according to the phase of the menstrual cycle into four groups: day 1–7 group, day 8–14 group, day 15–24 group and day 25 to end of the cycle group.

Results: Nausea and vomiting were reported in 46 patients (67.6%), and the incidence was higher in the day 25 to end of the cycle group than in the day 8–14 or day 15–24 groups, and higher in the day 1–7 group than in the day 8–14 group.

Conclusion: We conclude that emesis after epidural buprenorphine is related to the menstrual cycle.
Effect of P‐6 acupressure on prevention of nausea and vomiting after epidural morphine for post‐Cesarean section pain relief
Authors: Ho C.‐M. , Hseu S.‐S. , Tsai S.‐K. , Lee T.‐Y.
Published: January 2009

Background:Nausea and vomiting are important side effects following administration of epidural morphine for post‐Cesarean section pain relief. Stimulation of the P‐6 (Neiguan) acupoint is a traditional Chinese acupuncture modality used for antiemetic purpose; it has been found to be effective. The aim of this study was to evaluate the antiemetic effect of P‐6 acupressure in parturients given epidural morphine for post‐Cesarean section pain relief.

Method:In a randomized, double‐blind and controlled trial, sixty parturients receiving epidural morphine for post‐Cesarean section pain relief were investigated. Parturients were allocated to receive the acupressure bands or placebo bands on the P‐6 acupoint bilaterally before the administration of spinal anesthesia and were observed over a 48‐hour study period.

Results:The incidence of nausea and vomiting was significantly decreased from 43% and 27% in the control group, to 3% and 0% in the acupressure group, respectively (P<0.05).

Conclusion:The results demonstrate that prophylactic use of acupressure bands bilaterally on the P‐6 acupoint can significantly reduce incidence of nausea and vomiting after epidural morphine for post‐Cesarean section pain relief.
Cardiac failure aggravated by timolol eye drops: preoperative improvement by changing to pilocarpine
Authors: Bäckiund M. , Kirvelä M. , Lindgren L.
Published: January 2009

A 73‐year‐old woman with cardiac dysfunction had several episodes of severe bradycardia and pulmonary oedema when waiting for peripheral vascular surgery. She used timolol eye drops for primary open‐angle glaucoma. The first episode of pulmonary oedema occurred two weeks prior to and the second on the day before the planned surgery. There were another two episodes of pulmonary oedema before she was transferred to the Department of Internal Medicine where she had a further two episodes of cardiac failure. After changing timolol to pilocarpine eye drops, the patient's condition was stabilized, and two weeks later surgery and postoperative recovery were uneventful.
Pulmonary edema following intrauterine methylene blue injection
Authors: Trikha A. , Mohan V. , Kashyap L. , Saxena A.
Published: January 2009

Methylene blue is a commonly used dye in diagnostic procedures such as fistula detection, delineation of body tissues during surgery and for checking the patency of fallopian tubes. Many such dyes interfere with accurate measurement of oxygen saturation by a pulse oximeter. We report here a case in which methylene blue not only interfered with pulse oximetery but also caused pulmonary edema in an ASA grade 1 patient.
Gangrene and renal failure caused by dihydroergotamine used to treat raised intracranial pressure following head trauma
Authors: Gupta V. L. , Mjørndal T. O.
Published: January 2009

A case of peripheral gangrene and renal failure following the use of dihydroergotamine (DHE) for treatment of raised intracranial pressure (ICP) is reported. There have been several reports of vasospasm and peripheral gangrene caused by DHE used in combination with heparin for prevention of deep venous thrombosis. Clinical experience with the use of DHE in head trauma is limited. This case report emphasises the seriousness of the adverse effects associated with the use of this drug.
Additive analgesic effect of codeine and paracetamol can be detected in strong, but not moderate, pain after Caesarean section
Authors: Bjune K. , Stubhaug A. , Dodgson M. S. , Breivik H.
Published: January 2009

Background: A randomized, double‐blind, placebo‐controlled single oral dose study was done in order to examine whether codeine has an additive analgesic effect to that of paracetamol for moderate and strong postoperative pain after abdominal surgery. The maximum recommended single dose of paracetamol 1000 mg (Paracet®) was compared with a combination of a submnximal dose of paracetamol 800 mg plus codeine 60 mg (Paralgin forte®) and placebo for pain relief after Caesarean section in 125 patients.

Methods: Visual analogue pain intensity score (VAS 0–100 mm) and categorical pain relief score were recorded for 6 hours after the study drug intake. The main efficacy variables analyzed were: pain intensity difference and summed pain intensity differences during the first 3 and 6 h after study drug intake, total pain relief during the first 3 and 6 h, global evaluation score at the end of the observation period, and time to rescue analgesic.

Results: Because of protocol violations, 17 patients were excluded from the analysis of effects. Among the 108 patients included in the analysis of analgesic effect, 49 patients had moderate baseline pain (VAS between 40 and 60 mm on a 100 mm scale), and 59 patients had strong baseline pain (VAS more than 60 mm). In patients with strong baseline pain, statistically highly significant differences were documented in efficacy variables between the active drugs and placebo and between the two active drugs. However, in patients with moderate baseline pain, no differences were found between the study drugs in any of the analgesic efficacy variables.

Conclusion: This study thus confirms that codeine has additive analgesic effect to paracetamol in pain after surgery. Our results show the importance of initial pain intensity in postoperative assessment of analgesic drugs. Assay‐sensitivity and test power are increased by selecting patients with sufficiently high initial pain intensity and by comparing groups of patients with identical surgery and similar demographic variables.
Cardiovascular responses to experimental infra‐renal aortic cross‐clamping. Modulating effects of isoflurane, sodium nitroprusside and milrinone
Authors: Seeman‐Lodding H. , Biber B. , Martner J. , Pontén J. , Winsö O.
Published: January 2009

Background: Pharmacological control of blood pressure is usually indicated during aortic cross‐clamping (AXC). The aim of this study was to analyze the modulation by isoflurane (ISO), sodium nitroprusside (SNP) and milrinone (MIL) of the systemic circulatory responses to a standardized infra‐renal AXC.

Methods: Chloralose‐anaesthetized pigs were exposed to AXC at control (no vasoactive drugs) and during the administration of each of the drugs.

Results: During control, AXC increased mean arterial pressure (MAP, 17±4%) and systemic vascular resistance (SVR, 27±7%), but induced no significant changes in cardiac output (CO), heart rate (HR), pulmonary arterial pressures, pulmonary vascular resistance or central venous pressure. Low‐dose ISO (0.7%) and investigated doses of SNP and MIL did not significantly alter this response. High‐dose ISO (1.4%] attenuated the AXC‐induced increase in SVR, but not in MAP. All drugs decreased non‐clamp MAP levels. Therefore, with low‐dose ISO and with SNP or MIL, peak MAP during AXC was not significantly different fromcontrolnon‐clamp levels (i.e. prior to pharmacological or surgical interventions). High‐dose ISO was associated with a MAP during AXC that was below control non‐clamp levels.

Conclusions: The objective that during AXC MAP should not exceed control non‐clamp levels was achieveable by ISO, SNP or MIL. The modulating actions of the drugs on MAP during AXC were exerted mainly through reductions in non‐clamp levels. This systemic hypotension was associated with decreased CO and SVR during ISO, and with decreased SVR and increased HR during SNP and MIL. Attenuation of the AXC‐induced increase in SVR was produced only by 1.4% ISO.
A cost‐benefit evaluation of using propofol and alfentanil for a short gynecological procedure
Authors: Enlund M. , Kobosko P. , Rhodin A.
Published: January 2009

It is well established that the immediate recovery after propofol or alfentanil anesthesia is short. Although the drugs themselves are more expensive than older drugs, a potential for saving costs arises. Concerning the benefits in terms of late recovery, less information is available. With vaginal termination of pregnancy (VTP), anesthesia is supposed to be the major cause of sick‐leave. Does propofol and alfentanil anesthesia for VTP reduce sick‐leave compared with thiopental and nitrous oxide anesthesia, and do the increased costs of the drugs outweigh the reduced costs of sick‐leave?

Data were obtained from 39 of 40 patients in ASA class I accepted for VTP and allocated to either propofol and alfentanil anesthesia (PA) or thiopental and nitrous oxide anesthesia (TN). A questionnaire was filled in by the patients at home after regaining full fitness. The number of patients with a sick‐leave of 2 days or less in the groups was compared statistically with the number of patients with 3 days or more off work. The economic impact from the reported sick‐leave was calculated for each study group, using data from national statistics. The figures were compared with the calculated costs of the drugs. The median number of days of sick‐leave was 1 in the PA‐group and 2 in the TN‐group (range 0–3 and 0–5, respectively). Nineteen of the 20 patients in the PA‐group and 13 of the 19 patients in the TN‐group needed a short sick‐leave period of 2 days or less (one‐sided test of proportions, P<0.05). At the time of the study each patient was paid 210 SEK/day from the social insurance system and the mean cost of the drugs was 72 and 15 SEK/patient in the PA‐ and TN‐groups, respectively. Using the mean difference in sick‐leave between the groups of 0.8 days/patient (rather than the difference in median values of 1), a net gain of 111 SEK/patient was the result of changing from thiopental‐nitrous oxide anesthesia to propofol‐alfentanil anesthesia.

Although the cost of drugs was higher, costs for the social insurance system and for the individuals themselves were reduced by almost 50%, when using the propofol and alfentanil combination, resulting in an overall benefit corresponding to almost twice the increase in the cost of anesthesia.
Preoperative evaluation of intubation conditions in patients scheduled for elective surgery
Authors: Jacobsen J. , Jensen E. , Waldau T. , Poulsen T. D.
Published: January 2009

Prediction of a difficult airway is a continuing problem. Several tests have been developed in order to overcome this problem. It has been proposed that using more than one test could increase the degree of predictability. One hundred patients scheduled for general surgery were successfully evaluated using three methods: 1. The size of the tongue in relation to the oral cavity (Mallampati gradation). 2. The thyromental and the mandibular length. 3. The atlanto‐occipital angle. Seven patients had a difficult laryngoscopy and were difficult to intubate. It was possible to predict differenties in all seven patients, but it was found that only the Mallampati gradation and the atlanto‐occipital angle contributed significantly to predictability. The cost of predicting further difficulties in all patients with a difficult laryngoscopy was a false positive prediction in a further 13 patients who had no problems with laryngoscopy or intubation. By increasing the specificity of the tests the number of false positive classifications could be reduced to 10 patients, but this would have led to the missing of one patient with a difficult laryngoscopy.
Comparison of intubating conditions after rocuronium and suxamethonium following “rapid‐sequence induction” with thiopentone in elective cases
Authors: Sparr H. J. , Luger T. J. , Heidegger T. , Putensen‐Himmer G.
Published: January 2009

Background: Rocuronium (Org 9426) was shown to have the fastest onset of action of all currently available non‐depolarizing neuromuscular blocking drugs and to provide intubating conditions similar to those of suxamethonium 60 to 90 s after administration. We compared the intubating conditions after rocuronium and suxamethonium following rapid‐sequence induction of anaesthesia.

Methods: Fifty unpremedicated patients of ASA physical status I or II, scheduled for elective surgery were studied. Anaesthesia was induced with thiopentone 6 mg kg‐1 followed randomly by suxamethonium 1 mg kg‐1 or rocuronium 0.6 mg kg‐1 and, 45 s later, intubation was commenced. Muscle fasciculations, intubating conditions and intubation time, haemodynamic variables and oxygenation were assessed.

Results: Intubation time did not differ between suxamethonium (9.8±2.2 s) (mean±SD) and rocuronium (10.5±2.9 s), respectively. Intubating conditions were clinically acceptable (good or excellent) in all patients given suxamethonium and in 96% of the patients given rocuronium. However, the condition of the vocal cords was better (P<0.05) and diaphragmatic response to intubation was less pronounced with suxamethonium (P<0.05). Changes in heart rate and arterial blood pressure were similar in both groups.

Conclusion: The authors conclude that rocuronium is a suitable alternative to suxamethonium for rapid tracheal intubation even under unsupplemented thiopentone anaesthesia, at least in elective, otherwise healthy patients. Its use for rapid‐sequence induction under emergency conditions, however, needs further investigation.
The effect of succinylcholine on energy metabolism studied by 31 P‐NMR spectroscopy in rat denervated skeletal muscle
Authors: Mizogami M. , Fujibayashi T. , Harada J. , Goto Y.
Published: January 2009

Background: The goals of this study were: (1) to demonstrate the differences of metabolic changes induced by succinylcholine (SCh) administration between normal and denervated muscle by 31P‐NMR spectroscopy: (2) to determine whether three kinds of drugs (vecuronium, midazolam and magnesium sulfate) could prevent these metabolic changes.

Methods: Following unilateral sciatic nerve section, 20 male Wistar rats were studied at three‐week intervals. After SCh 1 mg·kg‐1 was administered intravenously, the changes of the inorganic phosphate/phosphocreatine (Pi/PCr) ratio, the β ATP/(PCr+Pi) ratio, and intracellular pH were measured by 31P‐NMR both in normal and denervated hind limb muscles of 5 rats. The other 15 rats were allocated to the pretreatment groups by the following drugs: vecuronium 0.02 mg·kg‐1, midazolam 0.1 mg·kg‐1 and magnesium sulfate 60 mg·kg‐1. After pretreatment 3 min before SCh administration, we measured the same parameters by 31P‐NMR.

Results: SCh administration did not change the Pi/PCr ratio in normal muscle, but significantly increased that in denervated muscle (P<0.05). This increase of the Pi/PCr ratio was also observed in all pretreated groups but was minimal as compared with that in non‐pretreatment denervated muscle.

Conclusion: These data suggested that SCh administration decreased the level of “energy reserve” in denervated muscle, and that this metabolic change was not totally inhibited by vecuronium, midazolam, or magnesium sulfate.
Rectal administration of morphine in children
Authors: Lundeberg S. , Beck O. , Olsson G. L. , Boreus L. O.
Published: January 2009

Background: There is limited knowledge about the pharmacokinetics of morphine and its metabolites after rectal administration in children. In this study the pharmacokinetics of two different rectal formulations of morphine were examined and compared with intravenous morphine.

Methods: Children undergoing elective surgery received rectal morphine 0.2 mg/kg before start of surgery. Ten children (mean age 14 months) received morphine rectally in a hydro‐gel formulation and another 10 children (mean age 16 months) received morphine rectally in a parenteral formulation. For comparison, 6 children (mean age 21 months) were given the same dose intravenously. The plasma concentrations of morphine, morphine‐3‐glucuronide (M3G) and mor‐phine‐6‐glucuronide (M6G) were measured by HPLC over 6 h after drug administration.

Results: The mean rectal bioavailability of morphine was 35% (range 18–59) after hydrogel administration and 27% (range 6–93) after the solution. Mean values of Cmax were 76 nmol/1 (25–129) and 56 nmol/1 (15–140), respectively. The results showed that morphine gel had a significantly higher bioavailability (P<0.02) than the solution. The ratios of plasma (M3G + M6G) to morphine were higher after rectal administration (mean 7.5–8.7) than after i.v. injection (mean 5.3), indicating the presence of first‐pass metabolism using the rectal route.

Conclusions: The rectal morphine hydrogel has pharmacokinetic properties which makes it a useful formulation for premedication and pain alleviation in paediatric patients.
MAC for halothane and isoflurane during normothermia and hypothermia in the newborn piglet
Authors: Satas S. , Haaland K. , Thoresen M. , Steen P. A.
Published: January 2009

Background: Halothane and isoflurane are frequently used in studies of perinatal hypoxia and ischemia. Little information exists on the minimum alveolar concentration (MAC) necessary to prevent movement to a painful stimulus in newborn pigs and no information on the effects of hypothermia on MAC in pigs. Hypothermia is currently investigated as a posthypoxic neuroprotective intervention.

Methods: The MAC of halothane and isoflurane necessary to prevent movement when a 25 cm hemostatic clamp was applied to the tail were determined in six 20–48‐hour‐old piglets, and when the same stimulus was applied to the hoof. MAC for halothane was first determined at 39°C, then at 35°C, whereafter halothane was discontinued and MAC for isoflurane determined first at 35°C and then at 39°C.

Results: In all six piglets MAC was lower at 35°C than at 39°C for both anesthetics with both tail and hoof determination, lower for halothane than isoflurane for both stimuli at both temperatures, and lower for tail than hoof determination for both anesthetics at both temperatures. For halothane at 39°C, mean (SD) MAC hoof was 0.82 (0.05)% vs tail 0.60 (0.12)%, and at 35°C, hoof 0.65 (0.06)% vs tail 0.42 (0.10)%. For isoflurane at 39°C, MAC hoof was 2.47 (0.28)% vs tail 1.83 (0.28)%, and at 35°C, hoof was 1.83 (0.18)% vs tail 0.85 (0.25)%.

Conclusion: In the newborn piglet, MAC should be determined by hoof clamp, MAC of isoflurane is approximately three times that of halothane, and both are reduced during hypothermia.
Effect of inhaled nitric oxide on venous admixture depends on cardiac output in patients with acute lung injury and acute respiratory distress syndrome
Authors: Benzing A. , Loop T. , Mols G. , Geiger K.
Published: January 2009

Background: It has been shown that inhaled nitric oxide (NO) reduces intrapulmonary venous admixture (QVA/QT) and improves oxygenation in patients suffering from acute respiratory distress syndrome (ARDS). The change in QVA/QT during NO inhalation varies individually. Factors known to influence the respiratory response to NO are the NO conceritration and the level of shunt before NO administration. Other factors that may modify the effect on gas‐exchange during NO breathing are unknown.

Methods: We studied the effect of 40 ppm inhaled NO on pulmonary gas‐exchange and haemodynamics in 37 patients with acute lung injury (ALI) and ARDS, respectively, and factors that may influence the respiratory response to NO.

Results: Inhalation of 40 ppm NO produced a decrease in mean pulmonary artery pressure (MPAP) from 33.1±7.2 to 30.2±6.8 (mean±SD) mmHg (P<0.0001) while pulmonary artery wedge pressure (PAWP), cardiac output and mean arterial pressure remained constant. Change in QVA/QT during NO inhalation depended on the preinhalation cardiac output and had no association with mixed venous oxygen tension, MPAP‐PAWP, and QVA/QT before NO delivery. QVA/QT decreased in 26 patients (group 1) and increased in 11 patients (group 2) during NO inhalation. In group 1, cardiac output was lower than in group 2 (8.6 vs. 12.2 1‐min‐1; P<0.0005).

Conclusion: We conclude that the change in venous admixture during inhalation of 40 ppm NO depends on cardiac output. If preinhalation cardiac output is high, 40 ppm NO can adversely affect gas exchange in patients with ALI and ARDS.
Thermoregulatory response in female patients during lower abdominal surgery in the head‐down tilt position
Authors: Hirose M. , Hara Y. , Iwasa J. , Matsusaki M.
Published: January 2009

Background: The head‐down tilt (HDT) position suppresses sympathetic nervous activity. We investigated the effect on thermoregulation of the HDT position during lower abdominal surgery under general anaesthesia.

Methods: Tympanic membrane temperature was measured to assess core temperature, and forearm‐fingertip and calf‐toe temperature gradients were used to assess peripheral vasoconstriction in 30 female patients less than 60 years of age.

Results: During surgery in the HDT position (n=10), the tympanic membrane temperature was similar to that of patients in the supine position (n = 10) (36.2°C and 36.2°C), but in patients operated in the HDT position and premedicated with an angiotensin converting enzyme inhibitor (5 mg of enalapril, n = 10) it was reduced (35.7°C, P<0.05). In both groups of patients operated in the HDT position, forearm and calf skin‐surface temperature gradients were lower by 2–3°C than those in patients operated in the supine position (P<0.05).

Conclusions: During lower abdominal surgery the head‐down tilt position does not augment core hypothermia in spite of suppressed peripheral vasoconstriction, and the renin‐angiotensin system may be of importance for thermoregulation.
Propofol influences the electroretinogram to a lesser degree than thiopentone
Authors: Tanskanen P. , Kylmä T. , Kommonen B. , Karhunen U.
Published: January 2009

Background: The Electroretinogram (ERG) is used clinically to assess the function of retina. Anaesthetic agents are known to affect ERG, and as anaesthesia is often needed in children and uncooperative patients, knowledge about its effects is of clinical importance. Barbiturates selectively depress ERG components, and we compared thiopentone with propofol to assess if the latter preserved retinal function better.

Methods: Ten pigs, average weight 17 kg (SD ± 2 kg) were anaesthetized randomly with propofol 10 mg kg‐1 or thiopentone 30 mg kg‐1. Anaesthesia was maintained by 65% nitrous oxide in oxygen and continuous infusion of the induction agent, i.e. 10 mg kg‐1 h‐1 of propofol, or 10 mg kg‐1 h‐1 for the first hour, then 5 mg kg‐1 h‐1 of thiopentone, with doses being based on pilot studies. After an interval of one week the programme was repeated using the other agent. After 40 minutes dark‐adaptation, responses to single flashes of graded intensities from a xenon flashlamp were recorded at five‐minute intervals. The a‐ and b‐wave amplitudes and implicit times (time to peak), and a‐wave slopes were determined.

Results: The b‐wave implicit time was significantly shorter during propofol anaesthesia than when using thiopentone. The effect was most pronounced at the lowest intensities (P < 0.01). No statistically significant differences were found in the amplitudes of the b‐waves. The a‐wave appeared at lower stimulus intensity (P < 0.05) and the a‐wave slopes were significantly steeper (P < 0.01) during propofol anaesthesia.

Conclusion: Propofol accordingly appeared to preserve the photoreceptor response better than thiopentone, and may therefore be considered to be more suitable for ERG recordings than thiopentone.
Lung uptake of lidocaine during hyperoxia and hypoxia in the dog
Authors: Hasegawa K. , Yukioka H. , Hayashi M. , Tatekawa S. , Fujimori M.
Published: January 2009

Background:Lidocaine has been shown to accumulate in the lung following its administration. This study was undertaken to determine effects of dose of lidocaine on lung uptake during hyperoxic and hypoxic ventilation.

Methods:Using cross‐circulation consisting of ventilation and constant‐flow perfusion of the left lower lobe independently from all other lobes of the dog lung under nitrous oxide and halolhane anesthesia, lidocaine was infused into the inflow system, so that plasma lidocaine concentrations in the inflow blood were maintained at 5, 10, 20, 40 and 70 μg/ml respectively during ventilation with 50% O2or 3% O2. During 20 μg/ml lidocaine infusion, indocyanine green (ICG), an intravascular marker, was mixed with the lidocaine solution, in such a fashion that plasma ICG concentration in the inflow blood was maintained at 20 μg/ml. Actual plasma lidocaine and ICG concentrations in blood drawn from the inflow ([Lid]pa, |ICG]pa)and the outflow ([Lid]pv, [ICG]pv) systems were measured 1, 3, 5, 7 and 10 minutes after the beginning of lidocaine infusion. Percent lung uptake of perfused lidocaine was calculated as (1‐([Lid]pv/[Lid]pa)/([ICG]pv/[ICG]pa)| x100.

Results:During ventilation hyperoxia, mean percent lung uptakes of lidocaine were 41–52% 1 minute after the beginning of lidocaine infusion, and decreased in time‐dependent fashion to 7–12% 10 minutes later. Curves of percent lung uptake of lidocaine over time were similar for the 5 predetermined lidocaine concentration groups (5–70 μg/ml). There were no significant differences in percent lung uptakes of lidocaine between the ventilation hyperoxia and hypoxia conditions.

Conclusions:These findings suggest that percent lung uptake of lidocaine is unaffected by hypoxic ventilation and by varying the concentration of lidocaine in the perfusion through the recipient dog lung lobe.
Left ventricular rupture following external chest compression
Authors: Fosse E. , Lindberg H.
Published: January 2009

A case of a 62‐year‐old woman suffering an acute cardiac arrest during a court dispute is presented. Cardiopulmonary resuscitation was immediately started by bystanders. In hospital there were signs of intrathoracic bleeding. A left thoracotomy revealed a cardiac rupture of the left ventricle and a large pericardial tear. Intraoperative evaluation of the heart as well as postoperative enzyme levels and ECG did not indicate acute myocardial infarction. The rupture may therefore be traumatic. The cardiac rupture was sutured five hours after the initial resuscitation, and the patient discharged from the intensive care unit two days after the rupture without clinical signs of neurological injury. A precordial thump is advised before start of external chest compression. One beneficial effect may be that the ventricles empty and the risk of traumatic rupture during compression is reduced.
Atelectasis and pulmonary shunting during induction of general anaesthesia ‐ can they be avoided?
Authors: Rothen H. U. , Sporre B. , Engberg G. , Wegenius G. , Reber A. , Hedenstierna G.
Published: January 2009

Background: Gas exchange is regularly impaired during general anaesthesia with mechanical ventilation. A major cause of this disorder appears to be atelectasis and consequently pulmonary shunt. After re‐expansion, atelectasis reappears very slowly if 30% oxygen in nitrogen is used, but much faster if 100% oxygen is used. The aim of the present study‐was to evaluate if early formation of atelectasis and pulmonary shunt may be avoided if the lungs are ventilated with 30% oxygen in nitrogen instead of 100% oxygen during the induction of general anaesthesia.

Methods: Twenty‐four adult patients with healthy lungs scheduled for elective surgery were investigated. During induction of anaesthesia, the lungs were manually ventilated via a face mask, using either 30% oxygen in nitrogen (group 1, n=12) or 100% oxygen (group 2, n=12). Atelectasis was estimated by computed x‐ray tomography and ventilation‐per‐fusion distribution with the multiple inert gas elimination technique, both awake and during general anaesthesia with mechanical ventilation.

Results: No atelectasis was present in the awake subjects. After induction of anaesthesia, the mean amount of atelectasis was minor (0.2±0.4 cm2) in group 1 and considerably greater (8.0±8.2 cm2) in group 2 (P<0.001). The pulmonary shunt was 0.3±0.7% of cardiac output in the awake subjects. This value increased to 2.1±3.8% in group 1 and to 6.5±5.2% in group 2 (P<0.05). The indices of VA/Q mismatch showed no difference between the two groups.

Conclusion: During induction of general intravenous anaesthesia in patients with healthy lungs, gas composition plays an important role for atelectasis formation and the establishment of pulmonary shunt. By using a mixture containing 30% oxygen in nitrogen, the early formation of atelectasis and pulmonary shunt may, at least in part, be avoided.
Continuous non‐invasive monitoring of energy expenditure, oxygen consumption and alveolar ventilation during controlled ventilation: validation in an oxygen consuming lung model
Authors: Holk K. , Einarsson S. G. , Svensson K. L. , Bengtson J. P. , Stenqvist O.
Published: January 2009

Background: We have developed a combined indirect calorimetric and breath‐by‐breath capnographic device (GEM) for respiratory monitoring: oxygen consumption (V̇O2), carbon dioxide excretion (V̇CO2), respiratory quotient (RQ), energy expenditure (EE), alveolar ventilation (V̇A) and dead space/total ventilation (VD/VT).

Methods: The device was tested in a lung model in which V̇O2 was achieved by combustion of hydrogen. V̇CO2 was achieved by delivering CO2 into the single alveolus combustion chamber. V̇O2, V̇CO2, compliance, and anatomical dead space could be varied independently.

Results: Measured V̇O2 was 101±3% (SD) of set value at a F1O2<0.6 and 101±7% at a F1O2>0.6 during 15 hours of testing. The corresponding V̇CO2 values were 99±2% and 102±7%. The GEM could with good accuracy measure accumulated energy expenditure (EE) during simulated unstable patient conditions up to a F1O2 of 0.8. At F1O2 above 0.8 V̇CO2 and V̇O2 could be estimated using a default RQ value of 0.85. On‐line estimated V̇A and VD/VT values could be obtained at any F1O2 up to 1.0. In a test sequence with stable V̇O2 and V̇CO2 the GEM adequately followed changes in V̇A, induced by changes in anatomical dead space, breathing frequency and compliance.

Conclusion: The overall performance of the device is satisfactory and well comparable with any equipment tested. It allows near‐continuous non‐invasive monitoring of EE, V̇O2, V̇CO2, V̇A, VD/VT in ventilated, critically ill patients, providing a rationale for ventilator settings and nutritional support.
Beneficial effects of pre‐treatment with vitamin A on cardiac and pulmonary functions in endotoxaemic pigs
Authors: Eriksson M. , Lundkvist K. , Drott P. , Saldeen T. , Eriksson Ö.
Published: January 2009

Background: Septic shock is associated with high mortality despite the development of new antibiotics. Since Vitamin A has an immunomodulating ability and is able to lower the concentrations of endotoxin and some cytokines, we decided to study whether supplementation with vitamin A may have a beneficial effect in experimental endotoxaemia.

Methods: A porcine model was used, in which normally bred (i.e., not vitamin A depleted) animals were anaesthetised, monitored and injected intramuscularly with a non‐toxic dose of vitamin A (230IU·kg‐1) (n=9) or the corresponding volume of vehicle (n=9) 1 hour before an infusion of purified E. coli endotoxin was given in a dose of 10 μg· kg‐1·h‐1 over 6 hours. Another 3 pigs also injected with vitamin A, but not endotoxin, served as controls.

Results: Vitamin A‐ and endotoxin‐injected pigs were significantly less affected in several circulatory and respiratory variables as compared to vehicle‐ and endotoxin‐injected animals (e.g., blood pressure; heart rate; cardiac index; pulmonary capillary wedge pressure; left and right ventricular stroke work indices; pH; base excess; oxygen delivery; and oxygen extraction). Vitamin A did not per se significantly affect these variables. Hb increased significantly in the vehicle group, indicating a more pronounced capillary permeability. Urinary output or fluid supply did not differ between the groups. Myocardial production of metabolites of prostacyclin or thromboxane A2 did not differ between the groups.

Conclusion: Pre‐treatment with vitamin A had a beneficial effect on several variables, such as oxygen delivery and metabolic acidosis in the endotoxaemic pig. Improvement of these variables is associated with increased survival in septic shock and may indicate reduced tissue hypoxia. Thus, vitamin A may turn out to be useful as a prophylactic agent in conditions where septic shock is apt to occur.
Ventilatory effects of laparoscopic cholecystectomy
Authors: Bures E. , Fusciardi J. , Lanquetot H. , Dhoste K. , Richer J.‐P. , Lacoste L.
Published: January 2009

Background: During laparoscopic cholecystectomy the arterial‐end‐tidal CO2 gradient (Fa‐ETCO2) has been variously shown to be unchanged, increased, decreased or even negative. The goal of this study was to evaluate Fa‐ETCO2, and to determine the proper contribution of V̇ECO2 and V̇A in regard to the increase of FETCO2.

Methods: Ventilatory patterns were studied in 15 ASA 1–2 patients (mean age±SD: 48.5±15.0) undergoing laparoscopic cholecystectomy, with intraperitoneal CO2 insufflation limited to 12 mmHg, 15° head‐up position, during general anaesthesia and controlled ventilation. The following were studied before, during, and after the pneumoperitoneum: FaCO2, FETCO2, nasopharyngeal temperature; dead space ventilation, and expired volumes using the Single Breath Test for CO2. V̇A was calculated as the alveolar fraction of expired VT multiplied by the respiratory frequency.

Results: During pneumoperitoneum it is shown that: 1) Fa‐ETCO2 either decreases and becomes even negative (n=8) (P<0.01), or stays unchanged (n=7), but never elevates; 2) V̇ECO2 increases (peak value: + 22.6%) (P<0.01); 3) V̇A is unchanged, and 4) dead space ventilation, determined in 7 patients, remains unchanged.

Conclusion: We conclude that only exogenous CO2 loading, and not V̇A, can explain such increase in FETCO2 and FaCO:, in cases of limited CO2 insufflating pressure in ASA 1–2 patients.
Conditions to optimise the reversal action of neostigmine upon a vecuronium‐induced neuromuscular block
Authors: Baurain M. J. , Dernovoi B. S. , D'Hollander A. A. , Hennart D. A. , Cantraine F. R.
Published: January 2009

Background: Since neostigmine was introduced for reversal of neuromuscular block, there has been controversy about the optimum dose for antagonizing neuromuscular block. The purpose of this study was to characterise recovery of neuromuscular transmission following a vecuronium‐induced block 15 min after neostigmine administration using different stimulation patterns, and to determine the effects of different doses of neostigmine given at various pre‐reversal twitch heights.

Methods: Adductor pollicis (AP) mechanical activity in response to low (0.1 and 2 Hz) and high (50 and 100 Hz) frequency stimulation, was recorded 15 min after 20, 40 and 80 μg/kg neostigmine, given to reverse a vecuronium‐induced block at 10, 25 and 50% pre‐reversal twitch height (TH). Fifty four ASA class I and II anaesthetised (methohexital, fentanyl, N2O/O2) young adult patients were studied and randomly allocated into 9 groups of 6 patients each.

Results: In contrast to twitch height (TH) and residual force after 50 Hz, 5 s tetanic stimulation (RF50Hz), the greater sensitivity of train‐of‐four (TOF) ratio and residual force after 100 Hz, 5 s tetanic stimulation (RF100Hz) points out the best reversal conditions (prereversal TH and the optimal neostigmine dose) (P<0.001, two‐way analysis of variance). The highest reversal scores (about 0.9 TOF ratio and RF100Hz) were obtained when 40 μg/ kg of neostigmine was given at 25 and 50% TH. A 0.9 TOF ratio was also observed when 40 μg/kg of neostigmine was given at 10% TH, but, under these conditions, RF100Hz was only 0.6 (P<0.05, Duncan test).

Conclusion: To optimise the reversal action of neostigmine in order to obtain the highest neuromuscular transmission recovery (0.9 TOF ratio and RF100Hz) during a vecuronium‐induced neuromuscular block, the 40 μg/kg dose has to be given at 25 to 50% recovery of TH.
Results of in vitro contracture testing of both parents of malignant hyperthermia susceptible probands
Authors: Islander G. , Bendixen D. , Ranklev‐Twetman E. , ØRding H.
Published: January 2009

Background: Malignant Hyperthermia (MH) is regarded as a dominantly inherited condition. Therefore, most investigators do not test the second parent if the first parent is found to be MH susceptible (MHS). The purpose of this study was to validate this policy.

Methods: In vitro contracture tests (IVCT) have been performed in both parents of 101 MH susceptible probands. Diagnoses were made according to the European MH group protocol and include MH susceptible (MHS), MH equivocal (MHE) and MH negative (MHN). Our control material consists of 60 patients without any personal or family history of MH.

Results: Thirty‐seven pairs of parents were MHS‐MHN, 20 were MHE‐MHN, 6 were MHS‐MHS, 20 were MHS‐MHE, 6 were MHE‐MHE, and 12 were MHN‐MHN. The frequency of MHE was greater in the parents than in the controls (26% versus 8%. P < 0.05). Several possible explanations exist: the IVCT produces false positive and/or false negative results; the MH genes may be more frequent in the population than previously expected; MH susceptibility may have more than one mode of inheritance; the mutation rate may not be negligible. Our test results in controls and fulminants point at a combination of these explanations.

Conclusions: We conclude that both parents should be tested whenever possible. For genetic research it is important that labelling any parent “presumed normal” may give misleading results.
No additional analgesic effect of intra‐articular morphine or bupivacaine compared with placebo after elective knee arthroscopy
Authors: Aasbø V. , Ræeder J. C. , Grøgaard B. , Røise O.
Published: January 2009

Background: Intra‐articular pain prophylaxis is a controversial measure, adding costs although the benefits are still disputed. We wanted to evaluate the effects of intra‐articular opioid or local anaesthesia or a combination of the two on postoperative analgesia and analgesic consumption after elective knee arthroscopy.

Methods: 107 patients with little or no preoperative pain and a minor surgical procedure were studied in a prospective, randomized double‐blind design. The patients received midazolam 0.03 mg/kg intravenously before induction of general anaesthesia with fentanyl 1–2 μg/kg and propofol 2.0 mg/kg intravenously. Anaesthesia was maintained by a total intravenous technique with propofol infusion supplemented with alfentanil 10 μg/kg when needed. The patients breathed oxygen/air through a laryngeal mask. By the end of the surgery they received 20 ml of test drug into the knee‐joint: Group I (BM): 20 ml of bupivacaine 2.5 mg/ml with 3 mg of morphine; Group II (B): 20 ml of bupivacaine 2.5 mg/ml; Group III (M): 20 ml isotonic saline with 3 mg morphine; Group IV (P): 20 ml of isotonic saline (placebo).

Results: There were no significant differences between the groups in: time to first analgesic administered, analgesic consumption during the pre‐or post‐discharge period, nausea, somnolence, side‐effects or postoperative pain perception during the first week.

Conclusions: Intra‐articular administration of morphine or bupivacaine is not indicated after elective knee‐arthroscopy in patients with minor pre‐operative pain and a small surgical trauma.
Postoperative pain relief by topical lidocaine in the surgical wound of hysterectomized patients
Authors: Sinclair R. , Westlander G. , Cassuto J. , Hedner T.
Published: January 2009

Background: To improve postoperative analgesia, local anesthetics have been administered perioperatively as infiltration or as aerosol in the surgical area. A previous study showed good analgesic effects by topical lidocaine in the wound in minor extraabdominal surgery (herniorraphy), while the same treatment in minor lower laparotomies did not improve postoperative analgesia. The present study investigated the effect of topical wound anesthesia using lidocaine aerosol on postoperative pain following major lower abdominal surgery.

Methods: Postoperative pain and analgesic requirements were studied in a double‐blind randomized trial including 30 hysterectomized patients. Patients were randomized to receive single wound treatment either with lidocaine aerosol 500 mg (100 mg/ml; Xylocain® aerosol, ASTRA, Sweden) (n=15) or placebo aerosol (n=15). Postoperative pain was evaluated by visual analogue scale (VAS). Requirements of opiate analgesics (buprenorphine) after surgery were monitored.

Results: Lidocaine aerosol induced a significantly (P<0.001) better analgesia at rest (VAS) and a significant (P<0.001) reduction in postoperative requirements of buprenorphine during the first 24 hours after surgery compared to placebo aerosol. Differences between the groups in pain scores (VAS) and buprenorphine requirements during the second postoperative day were not significant. Mean pain scores upon mobilization 24 h after surgery were significantly lower in the group receiving lidocaine aerosol (P<0.05). The plasma lidocaine concentration 4 h after the administration of lidocaine was well below toxic level and plasma lidocaine was detectable 48 h postoperatively. No drug‐related side effects were reported.

Conclsuion: A single dose of lidocaine aerosol topically administered in the surgical wound of hysterectomy patients improved analgesia during the first postoperative day with minimal risk of side effects.
Methylprednisolone shortens the effects of bupivacaine on sensory nerve fibersin vivo
Authors: Johansson A.
Published: January 2009

Perineural administration of corticosteroids is frequently applied in the treatment of a variety of chronic pain conditions. Methylprednisolone selectively inhibits the transmission of nerve impulses in C‐fibers whereas A‐fiber activity is unaffected.

In the present study the effect of a mixture of 0.05 ml of methyprednisolone (40 mg/ml) and 0.05 ml of bupivacaine (5 mg/ml) was compared to that of 0.05 ml bupivacaine (5 mg/ml) using a plantar nerve block model in the rat. The conduction of impulses in electrically stimulated A‐fibers of the plantar nerve was monitored by a bipolar volley recording from the sciatic nerve. Impulse conduction in electrically stimulated C‐fibers was studied through a C‐fiber evoked segmental flexion reflex.

The function of both the A‐fibers and the C‐fibers exposed to the methylprednisolone‐bupivacaine mixture showed a less profound block with signs of earlier recovery than those exposed to plain bupivacaine. The A‐fibers recovered somewhat faster than the C‐fibers.

It is postulated that methylprednisolone adjuvant to bupivacaine affects the intra‐axonal uptake of bupivacaine in C‐fibers but not in A‐fibers by some unknown mechanism. The effect seems to be longer lasting in C‐fibers than in A‐fibers.
Patient‐controlled analgesia with morphine and droperidol following caesarean section under spinal anaesthesia
Authors: Russell D. , Duncan L. A. , Frame W. T. , Higgins S. P. J. , Asbury A. J. , Millar K.
Published: January 2009

Background: The addition of droperidol to morphine for patient‐controlled analgesia reduces the incidence of nausea and vomiting, but may result in unwanted side effects.

Method: We studied 40 women randomised to receive morphine sulphate with or without added droperidol (10mg droperidol/60mg morphine) by patient‐controlled analgesia following elective caesarean section under spinal anaesthesia.

Results: Median morphine demand in the 20h after surgery was 74mg with morphine alone, and 53mg with added droperidol, the median consumption of which was 8.8mg. The incidence of nausea was reduced from 80% to 38.8% (P<0.01), and that of emesis from 55% to 16.7% (P<0.05) by the addition of droperidol. Psychomotor function was significantly impaired to a similar degree in both groups and there was no significant difference in sedation scores or pain scores. Subjective drowsiness which resulted in withdrawal from the study occurred in two patients, both of whom were receiving droperidol, and though all patients who completed the study were satisfied with their analgesia overall, significantly more of those receiving unsupplemented morphine (11/19 compared with 4/18, P<0.05) described it as excellent.

Conclusion: The addition of droperidol 10mg to morphine 60mg for PCA following caesarean section under spinal anaesthesia reduces the incidence of nausea and emesis, but may result in drowsiness, limiting the usefulness of the technique.