bluuebunny/crossref_metadata_2025 huggingface dataset:
Retrograde intubation with a Mini‐Trach II kit
Authors: Slots P. , Vegger P. B. , Bettger H. , Reinstrup P.
Published: December 2004

Background:  Retrograde intubation has been accepted internationally as a viable alternative for managing the difficult airway. Various techniques have been described to perform this procedure, however, difficulties have arisen on account of problems with suboptimal materials. We therefore describe a retrograde intubation technique using the knife and stiff plastic introducer from a Mini‐Trach II set from Portex Ltd (Kent, UK).

Methods:  The cricothyroid membrane was identified and using the knife from the mini‐trach set, incised longitudinally. The plastic introducer was inserted through the incision and maneuvered out through the mouth providing a guide over which the endotracheal tube was threaded. The technique was evaluated on 20 cadavers and thereafter used in four patients.

Results:  Mean intubation time in the 20 cadavers was 6.7 s (range 3–10) from incision to removal of the guide. Also, the technique was used successfully in four patients in whom anterograde attempts failed. In one of these patients the retrograde intubation was life saving.

Conclusion:  Retrograde intubation with a stiff curved plastic introducer was rapid and easy in cadavers and in four patients. In emergency situations where conventional intubation fails it may be life saving.
Nitric oxide increases dramatically in air exhaled from lung regions with occluded vessels
Authors: Fernández‐Mondéjar E. , Hambraeus‐Jonzon K. , Ronéus A. , Hedenstierna G.
Published: December 2004

Background:  We observed dramatic changes in exhaled nitric oxide concentration (ΔNOE) during wedge measurements, and hypothesised that occlusion and redistribution of pulmonary blood flow affects NOE.

Methods:  We inflated the balloon of the pulmonary artery catheter and measured NOE and central hemodynamics in closed chest anesthetised pigs (n = 11) ventilated with hyperoxic gas (fraction of inspired oxygen [FIO2] = 0.5), before and during lung injury, and in open chest anesthetised pigs (n = 17) before and during left lower lobar (LLL) hypoxia (FIO2 0.05), and during hyperoxic (FIO2 0.8) ventilation of the other lung regions (HL).

Results:  In the closed chest pigs NOE increased from 2.0 (0.9) to 3.4 (2.0) p.p.b. (P < 0.001) during wedge, and returned to 2.0 (1.0) p.p.b. when the balloon was deflated. The increase in mean pulmonary artery pressure (MPaP) during wedge was small and insignificant (P > 0.07). When the balloon was inflated in the right pulmonary artery in the open chest pigs, the perfusion of the HL decreased from 2.57 (0.58) to 2.34 (0.55) l min−1 (P < 0.001), and NOEHL increased from 2.5 (0.9) to 6.2 (3.2) p.p.b. (P < 0.001). The perfusion of the LLL increased from 0.33 (0.26) to 0.54 (0.34) l min−1 (P < 0.001), and NOELLL decreased from 1.7 (0.6) to 1.5 (0.5) p.p.b. (P < 0.001). Neither lung injury nor LLL hypoxia had any influence on ΔNOE (P > 0.07) during wedge. The correlation coefficient (R2) was 0.66 between changes in regional blood flow and ΔNOE, and 0.37 between changes in MPaP and ΔNOE.

Conclusions:  Nitric oxide concentration increases dramatically from lung regions with occluded vessels, whereas changes in MPaP have minor effects on NOE. This is an important fact to consider when comparing NOE within or between studies, and indicates a possible marker of diseases with occluded lung vessels.
Uvulopalatopharyngoplasty for sleep apnea in mentally retarded obese 14‐year‐old: an anaesthetic challenge
Authors: Govindarajan R. , Bakalova T. , Gerges M. , Mendelsohn M. , Michael R. , Abadir A.
Published: December 2004

Anaesthetic management of patients with obstructive sleep apnea for upper airway surgery has always been a challenging task. We report our anaesthetic approach for a young, mentally retarded obese patient with documented obstructive sleep apnea undergoing uvulopalatopharyngoplasty. The therapeutic intervention before, during and after operation is discussed.
Post‐thoracotomy pain after thoracic epidural analgesia: a prospective follow‐up study
Authors: Tiippana E. , Nilsson E. , Kalso E.
Published: December 2004

Background: Pain becomes chronic in 22–67% of patients who undergo a thoracotomy. Thoracic epidural analgesia (TEA) has replaced less invasive methods to manage postoperative pain. We wanted to find out if active use of TEA, combined with extended pain management at home, reduces the incidence of chronic post‐thoracotomy pain.

Methods: All consecutive thoracotomy patients during a 16‐month period were included. On the ward, pain was measured daily by VAS during rest and coughing and the consumption of analgesics was registered. The patients were interviewed one week after discharge by telephone and by a questionnaire after 3 and 6 months to find out how much pain they had.

Results: A total of 114 patients were recruited. The data were analysed from 89 patients who had had TEA and 22 who had had other methods. TEA was effective in alleviating pain at rest and during coughing. In the TEA patients the incidence of chronic pain of at least moderate severity was 11% and 12% at 3 and 6 months, respectively. One week after discharge 92% of all patients needed daily pain medication.

Conclusions: TEA seems effective in controlling evoked postoperative pain, but technical problems occurred in 24% of the epidural catheters. The incidence of chronic pain was lower compared with previous studies where TEA was not used. The patients had significant pain and needed regular pain medication and instructions during the first week after discharge. Extended postoperative analgesia up to the first week at home is warranted.
Does anaesthesia cause postoperative cognitive dysfunction? A randomised study of regional versus general anaesthesia in 438 elderly patients
Authors: Rasmussen L. S. , Johnson T. , Kuipers H. M. , Kristensen D. , Siersma V. D. , Vila P. , Jolles J. , Papaioannou A. , Abildstrom H. , Silverstein J. H. , Bonal J. A. , Raeder J. , Nielsen I. K. , Korttila K. , Munoz L. , Dodds C. , Hanning C. D. , Moller J. T.
Published: December 2004

Background:  Postoperative cognitive dysfunction (POCD) is a common complication after cardiac and major non‐cardiac surgery with general anaesthesia in the elderly. We hypothesized that the incidence of POCD would be less with regional anaesthesia rather than general.

Methods:  We included patients aged over 60 years undergoing major non‐cardiac surgery. After giving written informed consent, patients were randomly allocated to general or regional anaesthesia. Cognitive function was assessed using four neuropsychological tests undertaken preoperatively and at 7 days and 3 months postoperatively. POCD was defined as a combined Z score >1.96 or a Z score >1.96 in two or more test parameters.

Results:  At 7 days, POCD was found in 37/188 patients (19.7%, [14.3–26.1%]) after general anaesthesia and in 22/176 (12.5%, [8.0–18.3%]) after regional anaesthesia, P = 0.06. After 3 months, POCD was present in 25/175 patients (14.3%, [9.5–20.4%]) after general anaesthesia vs. 23/165 (13.9%, [9.0–20.2%]) after regional anaesthesia, P = 0.93.

The incidence of POCD after 1 week was significantly greater after general anaesthesia when we excluded patients who did not receive the allocated anaesthetic: 33/156 (21.2%[15.0–28.4%]) vs. 20/158 (12.7%[7.9–18.9%]) (P = 0.04). Mortality was significantly greater after general anaesthesia (4/217 vs. 0/211 (P < 0.05)).

Conclusion:  No significant difference was found in the incidence of cognitive dysfunction 3 months after either general or regional anaesthesia in elderly patients. Thus, there seems to be no causative relationship between general anaesthesia and long‐term POCD. Regional anaesthesia may decrease mortality and the incidence of POCD early after surgery.
Multiple organ failure and outcome of critically ill patients with haematological malignancy
Authors: Silfvast T. , Pettilä V. , Ihalainen A. , Elonen E.
Published: December 2004

Background: The number of failing organs systems in ICU patients with haematological malignancy is associated with outcome. The objective of this study was to assess short and long‐term survival in these patients with special reference to multiple organ failure reflected by the SOFA (Sequential Organ Failure Assessment) score.

Methods: Retrospective chart review of haematological patients admitted to the 10‐bed intensive care unit (ICU) of a tertiary level academic teaching hospital from 1994 to 1998. Of 31 admitted patients with the diagnosis of haematological malignancy, the charts of 30 were available for analysis.

Results: Univariate logistic regression analysis of factors previously shown to influence survival revealed that only admission SOFA score and untreated status of haematological disease were significantly associated with survival (P < 0.05). ICU, 3‐month and one‐year survival rates were 57% (17/30), 23% (7/30) and 20% (6/30), respectively. If maximal SOFA score during the ICU stay was included in a multivariate model comprising treatment status and effect, admission day SOFA and APACHE II scores, mechanical ventilation, renal replacement therapy and neutropenia, the maximal SOFA score became the only independent variable. All patients with an admission SOFA score exceeding 11 died in hospital. Leave‐one‐out method revealed that admission SOFA scores and the status of haematological disease (untreated or not) correctly classified 83% (25 of 30) of patients to survivors or non‐survivors.

Conclusions: Multiple organ failure assessed as SOFA score on admission and status of disease were associated with outcome in critically ill patients with haematological malignancy.
Differential release of matrix metalloproteinase‐9 and nitric oxide following infusion of endotoxin to human volunteers
Authors: Albert J. , Radomski A. , Soop A. , Sollevi A. , Frostell C. , Radomski M. W.
Published: December 2004

Background: Roughly 400 000 cases of sepsis occur every year in the United States only and this is associated with a very high mortality. Bacterial lipopolysaccharide (LPS) triggers systemic inflammatory reactions in sepsis. However, down‐stream cellular cascade initiated by LPS is still being elucidated. Nitric oxide (NO) and matrix metalloproteinases‐2 and ‐9 (MMP‐2 and MMP‐9) are known to be induced by LPS. We have investigated the release of NO, MMP‐2 and MMP‐9 following infusion of LPS to volunteers.

Methods: IPS (2 ng kg−1) was infused to 10 healthy volunteers. Before the experiments were started the subjects had an intravenous catheters placed. An electrocardiogram was also placed and monitored constantly. Body temperature was measured by ear thermometer every 10 min Venous blood was collected and cell‐free plasma assayed for the presence of MMP‐2 and MMP‐9 using zymography and NO using HPLC assay for NO metabolites, nitrite and nitrate.

Results: The administration of LPS resulted in increased body temperature and tachycardia. Time‐dependent release of MMP‐9(30 fold increase from the baseline) peaking at 2 h following infusion of LPS was observed. LPS did not significantly modify the activity of MMP‐2 (P > 0.05). Infusion of LPS did not significantly change the levels of nitrite and nitrate (from 60 ± 11 to 67 ± 10 µm, P > 0.05).

Conclusion: The release of MMP‐9, but not MMP‐2 or NO, is a sensitive index of endotoxaemia in humans. MMP‐9 release may contribute to the pathogenesis of sepsis via its pro‐inflammatory effects on the vasculature.
The effect of nitrous oxide on cerebral blood flow velocity in children anesthetized with propofol
Authors: Wilson‐Smith E. , Karsli C. , Luginbuehl I. A. , Bissonnette B.
Published: December 2004

Background: Propofol for maintenance of anesthesia by continuous infusion is gaining popularity for use in pediatric patients. Nitrous oxide (N2O) has been shown to increase cerebral blood flow velocity (CBFV) in both children and adults. To determine the effects of N2O on middle cerebral artery blood flow velocity (Vmca) during propofol anesthesia in children, Vmca was measured with and without N2O using transcranial Doppler (TCD) sonography.

Methods: Thirty ASA I or II children aged 18 months to 6 years undergoing elective urological surgery were enrolled. Anesthesia comprised propofol aimed at producing an estimated steady‐state serum concentration of 3 µg·ml−1 and a caudal epidural block. A transcranial Doppler probe was used to measure middle cerebral artery blood flow velocity. Each patient was randomized to receive a sequence of either Air/N2O/Air or N2O/Air/N2O in 35% oxygen. Fifteen min after each change in the N2O concentration, three measurements of cerebral blood flow velocity, blood pressure and heart rate were recorded. Ventilatory parameters and EtCO2 were kept constant throughout the study period.

Results: CBFV increased by 12.4% when air was replaced by N2O, and returned to baseline when N2O was subsequently removed. There was a 14% decrease in CBFV when N2O was replaced with air, which increased to baseline when air was subsequently replaced with N2O. Mean heart rate and blood pressure remained constant throughout the study period.

Conclusion: The effects of nitrous oxide on CBFV are preserved in children during propofol anesthesia.
Should patients undergoing a bronchoscopy be sedated?
Authors: Gonzalez R. , De‐La‐Rosa‐Ramirez I. , Maldonado‐Hernandez A. , Dominguez‐Cherit G.
Published: December 2004

Background: The techniques, drugs and depth of sedation for flexible fiberoptic bronchoscopy is controversial, and several reports consider that the routine use of sedation is not a prerequisite. We evaluate whether the addition of sedation with propofol improves patient tolerance, compared to local anesthesic of the airway only.

Methods: Eighteen patients with pneumonia undergoing flexible fiberoptic bronchoscopy were included in a randomized, single blind, prospective controlled study.

The non‐sedation group received airway topical anesthesia, whereas the sedation group received topical anesthesia and intravenous sedation with propofol. The degree of pain, cough, sensation of asphyxiation, degree of amnesia, global tolerance and acceptance of another bronchoscopy in the future were noted. Changes in blood pressure, heart rate and saturation of oxygen by pulse oximetry were also evaluated.

Results: The patients in sedation group had less cough (P < 0.05), pain (P < 0.01) and sensation of asphyxiation (P < 0.001). Global tolerance to the procedure was significantly better in the group under sedation (P < 0.01). These patients had total amnesia to the procedure (P < 0.0001), thus is more probable that will accept another bronchoscopy in the future (P < 0.01). There was a significant rise in heart rate and blood pressure in the patients without sedation. There were no differences in oxygen saturation (P = 0.75).

Conclusions: Our results show that if we administer propofol for sedation, in addition to local anesthesia of the airway, the tolerance to the procedure is much better. Also it appears that sedation with propofol is safe if we carefully select and monitor the patient.
Environmental temperature stress on drugs in prehospital emergency medical service
Authors: Helm M. , Castner Th , Lampl L.
Published: December 2004

Background: Drugs used in prehospital emergency medical service (EMS) in principle are subject to the same storage restrictions as hospital‐based medications. The prehospital emergency environment however, often exceeds these storage recommendations. Main stress factors are sunlight, vibration and extreme temperature, which may lead to alteration in chemical and physical stability of stored pharmaceuticals, as well as microbiological contamination and concentration enhancement of pharmacological inserts.

Methods: The purpose of this study was to determine the environmental temperature stress upon drugs used in the prehospital EMS under real mission conditions within different types of rescue vehicles (rescue helicopter [HEMS], ambulance [AMB] and emergency physician transport vehicle [EPTV]) during a ‘summer’ and ‘winter’ monitoring period (2 months duration each/location: southern Germany).

Results: Recorded temperatures varied from −13.2°C to +50.6°C. The recommended maximum storage temperature (+25°C) was exceeded in all rescue vehicles (33–45% of total exposure time), whereas the recommended minimum storage temperature (0°C) only fell short in the EPTV (19% of total exposure time). The daily maximum temperature variations ranged from 19.0°C (winter) to 32.9°C (summer).

Conclusions: These results show that even in a moderate climatic zone, drugs used in prehospital EMS are significantly influenced by temperature stress; furthermore, these results recommend the usage of temperature‐controlled drug boxes.
Slow rewarming improves jugular venous oxygen saturation during rewarming
Authors: Kawahara F. , Kadoi Y. , Saito S. , Goto F. , Fujita N.
Published: December 2004

Background: There have been many studies regarding the etiology of postoperative cognitive dysfunction after coronary artery bypass graft (CABG) surgery. Although its etiology remains unresolved, one possible factor related to postoperative cognitive dysfunction is a reduced internal jugular venous oxygen hemoglobin saturation (SjvO2) during the rewarming period. The purpose of this study was to examine the effect of rewarming rates on SjvO2 during rewarming.

Methods: One‐hundred patients scheduled for elective CABG surgery were randomly divided into two groups; control group (0.48 ± 0.09°C, n = 50), slow rewarming group (0.24 ± 0.09°C, n = 50). After the induction of anesthesia, a fiberoptic oximetry oxygen saturation catheter was inserted into the right jugular bulb to monitor SjvO2 continuously. Hemodynamic parameters, arterial and jugular venous blood gases were measured at nine time‐points.

Results: Cerebral desaturation (defined as a SjvO2 value below 50%) during rewarming was more frequent in the control group than in the slow group. Cerebral desaturation time (duration when SjvO2 was less than 50%) and the ratio of the cerebral desaturation time to the total CPB time in the control group differed significantly from those in the slow group (control group: 17 ± 11 min, 12 ± 4%, slow group: 10 ± 8 min, 7 ± 4%, respectively, P < 0.05). There was no significant difference in mini‐mental state examination on the day before the operation nor at 1 month after the surgery among four values (the day before the operation: control group; 48 ± 8, slow group; 48 ± 7, at one month after the surgery: control group; 46 ± 7, slow group; 45 ± 9).

Conclusions: A slow rewarming rate could reduce the chance of a decrease in SjvO2 during rewarming.
Analgesia following music and therapeutic suggestions in the PACU in ambulatory surgery; a randomized controlled trial
Authors: Nilsson U. , Rawal N. , Enqvist B. , Unosson M.
Published: December 2004

Background: This study was designed to determine whether music (M), or music in combination with therapeutic suggestions (M/TS) could improve the postoperative recovery in the immediate postoperative in daycare surgery.

Methods: One‐hundred and eighty‐two unpremedicated patients who underwent varicose vein or open inguinal hernia repair surgery under general anaesthesia were randomly assigned to (a) listening to music (b) music in combination with therapeutic suggestions or (c) blank tape in the immediate postoperative period. The surgical technique, anaesthesia and postoperative analgesia were standardized. Analgesia, the total requirement of morphine, nausea, fatigue, well‐being, anxiety, headache, urinary problems, heart rate and oxygen saturation were studied as outcome variables.

Results: Pain intensity (VAS) was significantly lower (P = 0.002) in the M (2.1), and the M/TS (1.9) group compared with the control group (2.9) and a higher oxygen saturation in M (99.2%) and M/TS (99.2%) group compared with the control (98.0%), P < 0.001, were found. No differences were noted in the other outcome variables.

Conclusion: This controlled study has demonstrated that music with or without therapeutic suggestions in the early postoperative period has a beneficial effect on patients' experience of analgesia. Although statistically significant, the improvement in analgesia is modest in this group of patients with low overall pain levels.
Lidocaine versus ropivacaine for continuous interscalene brachial plexus block after open shoulder surgery
Authors: Casati A. , Vinciguerra F. , Scarioni M. , Cappelleri G. , Aldegheri G. , Manzoni P. , Fraschini G. , Chelly J. E.
Published: December 2004

Background: This study compared the postoperative infusion of 1% lidocaine and 0.2% ropivacaine for continuous interscalene analgesia in patients undergoing open shoulder surgery.

Methods: Forty patients undergoing open shoulder surgery received an interscalene brachial plexus block with 30 ml of either 1.5% lidocaine (n = 20) or 0.5% ropivacaine (n = 20), followed by a continuous patient‐controlled interscalene analgesia with 1% lidocaine or 0.2% ropivacaine, respectively. A blinded observer recorded the quality of analgesia and recovery of motor function during the first 24 h of infusion.

Results: Onset of the block occurred after 7.5 (5–40) min with lidocaine and 30 (10–60) min with ropivacaine (P = 0.0005). Postoperative pain intensity was higher with lidocaine than ropivacaine for the first 8 h of infusion. The ratio between boluses given and demanded from the pump was 0.5 (0.13–0.7) with lidocaine and 0.7 (0.4–1.0) with ropivacaine (P = 0.005). Rescue IV tramadol was required during the first 24 h of infusion by 16 patients of the lidocaine group (84%) and eight patients of the ropivacaine group (46%) (P = 0.05). At the 16 h and 24 h observation times a larger proportion of patients receiving ropivacaine had complete regression of motor block (70% and 95%) than patients receiving lidocaine (50% and 55%) (P = 0.05 and P = 0.013, respectively).

Conclusions: Although 1% lidocaine can be effectively used for postoperative patient‐controlled interscalene analgesia, 0.2% ropivacaine provides better pain relief and motor function.
Effects of intrathecally administered dexmedetomidine, MPV‐2426 and tizanidine on EMG in rats
Authors: TALKE P. , Xu M. , Paloheimo M. , Kalso E.
Published: December 2004

Background: When administered intrathecally, alpha‐2 adrenergic agonists produce spinally mediated antinociception, but also rapidly redistribute to supraspinal sites. This investigation the compared EMG effects of intrathecally administered dexmedetomidine, MPV‐2426 (fadolmidine), and tizanidine in Sprague‐Dawley rats, which has not been previously described.

Methods: We studied electromyographic (EMG) responses of the head and gastrocnemius muscles, antinociception using the tail‐flick test, and sedation by using observer assessment. Saline, dexmedetomidine (0.5 µg, 2.5 µg and 12.5 µg), MPV‐2426 (2 µg, 10 µg and 50 µg) and tizanidine (2 µg, 10 µg and 50 µg) were administered intrathecally.

Results: Tizanidine 50 µg, MPV‐2426 10 µg and 50 µg, and dexmedetomidine 2.5 µg and 12.5 µg, decreased EMG activity (P < 0.005). Dexmedetomidine 12.5 µg, MPV‐2426 50 µg, and tizanidine 10 µg and 50 µg increased tail‐flick latencies (P < 0.01). Dexmedetomidine alone significantly increased the magnitude of observer‐assessed sedation (P < 0.0001).

Conclusion: We conclude that in rats, intrathecally administered dexmedetomidine, MPV‐2426 and tizanidine have dose‐dependent effects on EMG. At antinociceptive doses, the EMG effects of these three alpha‐2 adrenergic agonists differ (dexmedetomidine > MPV‐2426 > tizanidine).
Anesthetic management of a patient with Weill–Marchesani syndrome
Authors: Dal D. , S¸ahin A. , Aypar Ü.
Published: December 2004

Weill–Marchesani syndrome is characterized by short stature, brachydactylyl, myopia, microspherophakia, lens dislocation, glaucoma, joint stiffness, restricted articular movements and facial features. The anesthetic management of an 11‐year‐old‐male patient with diagnosis of this syndrome is reported.
Catecholamine release during laparoscopic fundoplication with high and low doses of remifentanil
Authors: Myre K. , RÆder J. , Rostrup M. , Buanes T. , Stokland O.
Published: December 2004

Background:  Reports on stress responses to laparoscopic surgery have been conflicting. Depth of anesthesia may influence the neuro‐hormonal release, including catecholamines. Opioids depress general sympathetic activation in a dose‐dependent manner. We investigated the hypothesis that remifentanil would depress the catecholamine response to pneumoperitoneum and laparoscopic surgery differently with a high dose (HD) compared with a low dose (LD).

Methods:  In a randomized, prospective study we investigated 18 ASA I–II patients undergoing laparoscopic fundoplication with an intra‐abdominal pressure of 12 mmHg. The patients were randomized to receive either a LD (0.13 μg kg−1.min−1) or HD (0.39 μg kg−1.min−1) of remifentanil with a target‐controlled infusion (TCI) technique. Bispectral index of EEG (BIS) was maintained at 40–55 by propofol delivered by a TCI system. Arterial catecholamines were analyzed at different times during the procedure.

Results:  Norepinephrine increased equally in both groups during pneumoperitoneum and surgical intervention. Epinephrine stayed low in the HD‐group, while increasing during surgery in the LD‐group.

Conclusion:  High dose of remifentanil depressed the epinephrine response to pneumoperitoneum and surgery, indicating no general activation of the sympathetic nervous system. Neither a LD nor HD of remifentanil depressed the norepinephrine response during pneumoperitoneum. This suggests a centrally independent release of norepinephrine.
Propofol pharmacokinetics in a dwarfism patient
Authors: Tsubokawa T. , Yamamoto K. , Komuro A. , Ishizuka S. , Kobayashi T.
Published: December 2004

Pharmacokinetic information is important to control anesthetic depth. However, there are few available pharmacokinetic data of propofol in dwarfism patients. We anesthetized a dwarfism patient who underwent spinal decompression, and investigated the pharmacokinetics of propofol. The patient was a 40‐year‐old man suffering from muscle weakness and numbness in the arms. The operation consisted of two stages; anterior approach in the supine position and posterior approach in the prone position. We also obtained arterial blood for pharmacokinetic analysis. Distribution volume at steady‐state and clearance in the supine position was 180 and 0.92 l min− 1, respectively, and in the prone position 127 and 0.74 l min− 1, respectively, in spite of a continuous infusion of dopamine. The data in the supine position were well predicted by Gepts' parameters (used in Diprifusor® Zeneca Ltd, Cheshire, UK), which means the target‐controlled infusion (TCI) technique can be available in the supine position, while attention is necessary to avoid overdosing when a patient is placed in the prone position.
Transient locked‐in syndrome resulting from stellate ganglion block in the treatment of patients with sudden hearing loss
Authors: Tüz M. , Ero?lu F. , Do?ru H. , Uygur K. , Yavuz L.
Published: December 2004

Stellate ganglion blockage (SGB) is a local anesthetic procedure intended to block the lower cervical and upper thoracic sympathetic chain and is one of the treatment modalities for a wide range of disorders such as sudden hearing loss, Menier's disease, stroke, sudden blindness, shoulder/hand syndrome and vascular headache. The complications of SGB are recurrent laryngeal or phrenic nerve block, pneumothorax, unconsciousness, respiratory paralysis, convulsions and sometimes severe arterial hypotension. We present a case with transient locked‐in syndrome following SGB for the management of sudden hearing loss. The risk of an intra‐arterial injection can be eliminated by rotating the needle, as is described in this report.
Hyperoxia and the cerebral hemodynamic responses to moderate hyperventilation
Authors: Johnston A. J. , Steiner L. A. , Balestreri M. , Gupta A. K. , Menon D. K.
Published: December 2004

Background: A reduction in the arterial partial pressure of CO2 (PaCO2) leads to a rapid reduction in cerebral blood flow (CBF). However, despite continuing hypocapnia there is secondary recovery of CBF over time as a result of increases in lactic acid production. Hyperoxia is thought to modulate the production of lactic acid. This study examined the kinetics of middle cerebral artery flow velocity (MCA FV) reduction during hyperventilation, and its modulation by hyperoxia.

Methods: Cerebral blood flow was assessed using transcranial Doppler ultrasound in nine healthy, awake human volunteers. Subjects were ventilated, via a mouthpiece, to achieve a stable end‐tidal CO2 (PETCO2). After a 20‐min baseline period the minute volume on the ventilator was passively increased by approximately 20% to reduce PETCO2 by 0.75–1 kPa. After a 10‐min stabilization period the new PETCO2 level was maintained at a constant level for 20 min, and MCA FV recovery was measured during this 20‐min period. Subjects undertook the protocol breathing air and breathing 100% oxygen.

Results: The PETCO2 level was (mean ± SD) 4.9 ± 0.4 kPa (normoxia baseline), 4.0 ± 0.3 kPa (normoxia hyperventilation), 4.6 ± 0.4 kPa (hyperoxia baseline) and 3.9 ± 0.4 kPa (hyperoxia hyperventilation). CO2 reactivity was significantly lower with normoxia than hyperoxia (16.5 ± 3.8 vs. 21.2 ± 4.6 % kPa−1; P< 0.05). Middle cerebral artery FV recovery was significantly more rapid with normoxia than hyperoxia (0.23 ± 0.17 vs. 0.08 ± 0.1 % baseline min−1; P< 0.01).

Conclusions: Our results suggest that cerebral hemodynamic responses to moderate hyperventilation are different in normoxic and hyperoxic conditions. Clinical assessment of CO2 reactivity and CBF recovery during hyperventilation should take the degree of arterial oxygenation into account.
Nitrous oxide anesthesia and intravitreal gastamponade
Authors: ÅStröm S. , Kjellgren D. , Mönestam E. , Bäcklund U.
Published: December 2004

The right eye of a 66‐year‐old man was operated with vitrectomy and peeling of an epiretinal membrane. Perioperatively, the eye was filled with 20% SF6 gas to tamponade retinal breaks. Five days later the patient underwent prostatectomy under general anesthesia using nitrous oxide. Postoperatively the eye had no light perception as a result of ischemic retinopathy.

The movement of nitrous oxide into gas‐containing spaces in the body has been known for a long time. The use of nitrous oxide in patients with intravitreal gas will elevate the intraocular pressure with risk for closure of the central retinal artery. The present case report highlights the problems that can occur when preoperative assessment is carried out a long time before surgery.
Randomized, double‐blind, placebo‐controlled study of the effect of rectal paracetamol on morphine consumption after abdominal hysterectomy
Authors: Kvalsvik O. , Borchgrevink P. C. , Hagen L. , Dale O.
Published: December 2004

Background: Paracetamol is widely used for postoperative analgesia. The effect is well documented in minor and moderate extensive surgery, but the effect of paracetamol as an adjunct to opioids in major abdominal surgery is less examined.

Methods: Seventy‐eight patients scheduled for elective, benign, and abdominal hysterectomy were included in a prospective, randomized, double‐blind, parallel group, placebo‐controlled study to evaluate the effect of rectal paracetamol in conjunction with intravenous patient‐controlled analgesia (PCA) morphine. Paracetamol 1000 mg or placebo suppositories were given four times daily during the 60‐h study period. I.V. morphine was administered via a PCA pump, limited to maximum of 12 mg h−1. Morphine consumption, pain and morphine‐related adverse effects were recorded. A single‐point analysis was comprised of serum concentrations of paracetamol and morphine.

Results: Sixty patients were evaluated: 30 in each group. A 16.6% reduction in overall‐accumulated morphine consumption in the treatment group (99.6 vs. 83.3 mg) was observed (NS, P = 0.06). Mean paracetamol serum concentration was 0.03 mmol l−1 (range: 0.01–0.06 mmol l−1). None of the patients had a paracetamol concentration within the therapeutic range for antipyretic efficacy. Patients with a higher paracetamol concentration had a lower concomitant morphine (P = 0.025) and morphine‐6‐glucuronide (P = 0.014) concentration 2 h after paracetamol administration.

Conclusion: A dosage of rectal paracetamol 1000 mg four times daily is too low, as all displayed a suboptimal serum paracetamol concentration. To study the effect of rectal paracetamol after major surgery we have to increase the dose, as higher serum concentrations of paracetamol may cause lower serum concentrations of morphine.
Pretreatment with sufentanil reduces myoclonus after etomidate
Authors: Hueter L. , Schwarzkopf K. , Simon M. , Bredle D. , Fritz H.
Published: December 2004

Background: Myoclonic movements are a common problem during the induction of general anesthesia with etomidate. We investigated the influence of pretreatment with the opioid sufentanil on the incidence of etomidate‐induced myoclonus.

Methods: Forty female patients (ASA physical status I–III) were randomly assigned to receive double‐blinded either 0.3 µg kg−1 of sufentanil or placebo 150 s before the induction of sleep with 0.3 mg kg−1 of etomidate. The patients were observed for any myoclonic movement. Grade of dizziness, breathing frequency, non‐invasive blood pressure and heart rate were measured during the study period.

Results: None of the 20 patients receiving sufentanil had myoclonic movements after the administration of etomidate, whereas 16 patients in the placebo group (80%) experienced such movements (P<0.01). No cases of apnoea before induction of sleep were seen in the sufentanil group.

Conclusion: Sufentanil 0.3 µg kg−1 is an effective and safe drug to reduce myoclonus after etomidate without causing any harmful side‐effect.
High‐dose glucose‐insulin‐potassium after cardiac surgery: a retrospective analysis of clinical safety issues
Authors: Szabó Z. , Håkanson E. , Maros T. , Svedjeholm R.
Published: December 2004

Background: Metabolic treatment with insulin or glucose‐insulin‐potassium (GIK) has received attention in association with myocardial infarction, cardiac surgery and critical care. As a result of insulin resistance during neuroendocrine stress, doses of insulin up to 1 IU kg−1 b.w.*h are required to achieve maximal metabolic effects after cardiac surgery. The clinical experience with regard to safety issues of such a high‐dose GIK regime in critically ill patients after cardiac surgery is reported.

Methods: Retrospective, observational study involving all patients treated with high‐dose GIK after cardiac surgery during one year in a cardiovascular center at a University Hospital.

Results: Eighty‐nine patients out of 854 adult patients undergoing cardiac surgery were treated with high‐dose GIK. Mean age was 69 ± 1 years, Higgins score 5.3 ± 0.3. Preoperatively 31.4% had left ventricular function EF≤0.35 and 32.5% had sustained a myocardial infarct during surgery. Mortality was 5.6% and the average ICU stay was 3.7 ± 0.5 days. The main indication for GIK was intraoperative heart failure (69.7%). The average glucose infusion rate during the first 6 h was 4.22 ± 0.15 and 4.91 ± 0.14 mg kg−1 b.w.*min, respectively, in diabetic and non‐diabetic patients (P = 0.023). Blood glucose and s‐potassium control was acceptable.

Conclusions: The high‐dose GIK regime allowed substantial amounts of glucose to be infused both in diabetic and critically ill patients with maintenance of acceptable blood glucose control. Provided careful monitoring, this regime can be safely used in clinical practice and deserves further evaluation for treatment of critically ill patients following cardiac surgery.
Resource use in the ICU: short‐ vs. long‐term patients*
Authors: Stricker K. , Rothen H. U. , Takala J.
Published: December 2004

Background: Intensive care medicine uses a disproportionate share of medical resources, and little is known about the distribution of resources between different patient groups.

Methods: In this prospective observational study, all patients admitted between 1 January 1998 and 31 December 1999 to our medical‐surgical university's ICU were assigned to one of two groups according to length of stay (LOS): patients staying more than 7 days in the unit (group L) and those staying a maximum of 7 days (group S). Resource use was estimated using TISS−28, number of nursing shifts, use of mechanical ventilation, and use of renal replacement therapy. Further, SAPS II and ICU and hospital mortalities were recorded.

Results: Of 5481 patients, 583 (10.6%) were in group L and 4898 in group S (89.4%). Patients in group L were more severely sick upon admission than those in group S. Patients in group L stayed a total of 9726 days in the ICU (52.5% of the total LOS). In group L, 69.2% of all shifts with respiratory support and 80.1% of all shifts with renal replacement were used. Further, group L patients consumed 53.4% (909225) of all TISS points provided. The ICU‐mortality rates were 14.4% in group L and 7.2% in group S, and the hospital mortality rates were 19.9% and 9.8%, respectively. A mean of 1898 TISS points was used per patient surviving the hospital stay in group L compared with 190 points in group S.

Conclusions: In this university‐based, medical–surgical adult ICU, 11% of all patients stayed more than 7 days in the unit and consumed more than 50% of all resources. Thus, a highly disproportionate amount of resources were used per survivor in group L compared with those in group S.
Preload changes by positive pressure ventilation can be used for assessment of left ventricular systolic function
Authors: Sellgren J. , Söderström S. , Johansson G. , Biber B. , Häggmark S. , Pontén J.
Published: December 2004

Background: Assessment of preload independent left ventricular function with conductance volumetry is traditionally accomplished by inflating a balloon in the inferior caval vein. Our aim was to investigate if a similar change in preload could be achieved by positive pressure ventilation with large tidal volume.

Methods: Conductance volumetry generating left ventricular pressure‐volume loops was used in seven pentobarbital‐anesthetized pigs. Changes in preload recruitable stroke work were studied, comparing the effects of inferior vena cava occlusion (IVCO) or large tidal volume (LTV). Cardiodepression was induced by halothane anesthesia and halothane + phenylephrine, and stimulation by epinephrine infusion.

Results: Although the decreasis in left ventricular end diastolic volume was slightly less with LTV (16.5 ± 1.7 ml, mean ± SEM) than with IVCO (22.4 ± 1.7 ml) (P < 0.0001) the PRSW‐slopes showed a high degree of correlation (r=0.80, P < 0.0001). Although peak tracheal pressures increased significantly to 27.8 ± 0.9 mmHg during LTV, esophageal pressures (used as an indicator of pericardial pressure) were unchanged.

Conclusions: Positive pressure ventilation with LTV is similar to IVCO in creating transient changes in preload, necessary for assessment of left ventricular systolic function. This observation was valid also during drug‐induced cardiac depression and stimulation. The preload recruitable stroke work used for this validation was shown to be a reliable and stable method.
Rocuronium combined with i.v. lidocaine for rapid tracheal intubation
Authors: Yörükoglu D. , Aşik Ý. , Ökten F.
Published: December 2004

Background: Rocuronium (ORG 9426) has been shown to have an onset of action more rapid than other nondepolarizing neuromuscular blocking agents and to provide intubating conditions similar to those of succinylcholine 60–90 s after administration. We compared the intubating conditions and hemodynamic changes after the administration of rocuronium 0.6 mg kg−1 and lidocaine 1.5 mg kg−1 with rocuronium alone and succinylcholine 60 and 90 s after administration.

Methods: One hundred and twenty‐five adult patients of ASA physical status I or II scheduled for elective surgery were randomly divided into five groups. After propofol administration in all patients, patients in group Su (succinylcholine), group R60 (rocuronium) and group RL60 (rocuronium‐lidocaine) were intubated within 60 s, while groups RL90 and R90 were intubated 90 s after the administration of rocuronium and succinylcholine. Laryngoscopy was performed and intubating conditions were graded by an experienced anesthetist blind to the muscle relaxant allocation.

Results: In this study, groups Su, RL60, R90 and RL90 had similar intubation scores, which were significantly better than that for group R60. Heart rate did not increase after intubation in groups Su, RL60 and RL90.

Conclusion: The combination of lidocaine (1.5 mg kg−1) and low‐dose rocuronium (0.6 mg kg−1) along with propofol is clinically equivalent to succinylcholine, improves intubating conditions in 60 s and effectively blocks increases in heart rate after intubation.
Inhibitory effects of desflurane and sevoflurane on contractions of isolated gravid rat myometrium under oxytocin stimulation
Authors: Dogru K. , Yildiz K. , Dalgiç H. , Sezer Z. , Yaba G. , Madenoglu H.
Published: December 2004

Background: We studied the inhibitory effects of desflurane and sevoflurane on oxytocin‐induced contractions of isolated gravid rat myometrium.

Methods: Twenty strips were obtained from rats and these were randomly assigned into two groups. The effects of desflurane and sevoflurane were evaluated by treating strips with oxytocin alone 2×10−9 M or with oxytocin after desflurane and sevoflurane at 0.5, 1, and 2 MAC.

Results: Oxytocin significantly increased the amplitude and duration of contractions (P< 0.05), but it did not increase the frequency. The duration (84%, 79%), amplitude (90%, 84%) and frequency (88%, 75%) were inhibited at 2 MAC of desflurane and sevoflurane, respectively.

Conclusion: These results suggest that the in vitro application of desflurane and sevoflurane similarly inhibit oxytocin‐induced myometrial contractions of gravid rat in a dose‐dependent manner.
Response to the prone position in spontaneously breathing patients with hypoxemic respiratory failure
Authors: Valter C. , Christensen A. M. , Tollund C. , SchØnemann N. K.
Published: December 2004

Objectives: The prone position is used for intubated patients with adult respiratory distress syndrome (ARDS) and acute lung injury (ALI). The physiological changes associated with the prone position in nonintubated patients may be even more favorable than in intubated patients. We examined the effect of the prone position on arterial blood gases and patient compliance in four awake, nonintubated patients with hypoxemic respiratory failure.

Design: We present four consecutive cases of hypoxemic respiratory failure, in which mechanical ventilation was indicated. An attempt was made to avoid assisted ventilation by placing patients in the prone position, while breathing spontaneously. The effect on the clinical condition and the changes in blood gases were registered.

Results: We found good patient tolerance. A rapid increase in PaO2 was found, and intubation was avoided in all patients. No significant complications were registered.

Conclusion: The prone position may prove beneficial in some cases of hypoxemic respiratory failure, even in awake patients, by avoiding mechanical ventilation and ventilator‐associated complications.
Racemic ketamine does not abolish cerebrovascular autoregulation in the pig
Authors: Schmidt A. , Ryding E. , Åkeson J.
Published: December 2004

Background: Little is known about the influence of racemic ketamine on autoregulation of cerebral blood flow (CBF), and available reports regarding its influence on cerebral hemodynamics are contradictory. This study was designed to evaluate cerebrovascular responses to changes in the mean arterial pressure (MAP) during ketamine anesthesia.

Methods: In eight normoventilated pigs anesthesia was induced with propofol and maintained by i.v. infusion of ketamine (15.0 mg kg−1.h−1) during measurements. The intra‐arterial xenon clearance technique was used to calculate CBF. Balloon‐tipped catheters were introduced in the inferior caval vein and mid‐aorta, and increases or decreases by up to 40% in mean arterial pressure (MAP) in random order were achieved by titrated inflation of these balloon catheters. Cerebral blood flow was determined at each MAP level. Regression coefficients of linear pressure‐flow curves were calculated in all animals.

Results: From the mean baseline level (101 mmHg) MAP was reduced by 20% and 40%, and increased by 26% and 43%. The maximal mean increase and decrease in MAP induced a 12% increase and a 15% decrease, respectively, of CBF from the mean baseline level (52.6 ml.100 g−1.min1). The 95% confidence interval (−0.02; 0.38) of the mean regression coefficient of individual pressure‐flow curves does not include the regression coefficient (0.64) of a linear correlation between MAP and CBF including origo (correlation coefficient 0.99), which indicates complete lack of cerebrovascular autoregulation.

Conclusions: We conclude that autoregulation of CBF is not abolished during continuous ketamine infusion in normoventilated pigs and that previous divergent conclusions are unlikely to be associated with severe impairment of cerebrovascular autoregulation.
Performance of the rapidly extracted auditory evoked potentials index to detect the recovery and loss of wakefulness in anesthetized and paralyzed patients
Authors: Ge S. J. , Zhuang X. L. , Wang Y. T. , Wang Z. D. , Chen S. L. , Li H. T.
Published: December 2004

Background: The rapidly extracted auditory evoked potentials index (A‐lineTM ARX Index or AAI) has been proposed as a method to measure the depth of anesthesia. A prospective study was designed to assess the performance of AAI to detect the recovery and loss of wakefulness in anesthetized and paralyzed patients.

Methods: Fourteen adult patients undergoing elective surgery were anesthetized with propofol 1.5 mg kg−1, vecuronium 0.1 mg kg−1 and further propofol 1.0 mg kg−1. Wakefulness was measured by the ability of the patient to respond to command using the isolated forearm technique (IFT). After the patient responded, propofol was infused at 10 mg kg−1 · h−1 until wakefulness (responsiveness) was lost. The AAI was recorded continuously throughout the study and analyzed off‐line.

Results: The AAI showed a significant difference between the values registered during, 30 s before and 30 s after the recovery, and also between 30 s before and 30 s after the loss of wakefulness. The prediction probability (Pk) values for AAI were 0.786 and 0.864 during the transitions from unresponsiveness to responsiveness and from responsiveness to unresponsiveness. The area under the receiver operating characteristic curve for the responsive and unresponsive values was 0.926 (SE 0.002, 95% CI 0.922–0.931), and the AAI values of approximately 5%, 50% and 95% predicted probability of wakefulness were 19, 29 and 39, respectively.

Conclusion: The AAI may be a good predictor of recovery and loss of wakefulness for anesthetized and paralyzed patients.