bluuebunny/crossref_metadata_2025 huggingface dataset:
The importance of tail temperature monitoring during tail‐flick test in evaluating the antinociceptive action of volatile anesthetics
Authors: Sawamura S. , Tomioka T. , Hanaoka K.
Published: March 2003

Background:  Tail‐flick (TF) latency can be influenced by tail‐skin temperature (TT), and treatments that raise TT can mimic hyperalgesia on a TF test. As volatile anesthetics can raise TT via heat redistribution, their antinociceptive action can be hidden or obscured in a TF test. We tested the hypothesis that TT monitoring improves the efficiency of TF tests in evaluating the antinociceptive action of volatile anesthetics.

Methods:  The relationship between TT and TF latency was first explored under varied TTs in 12 rats. Then, TT and TF latency were measured before and during isoflurane exposure (1.2%). In the low temperature group (n=6), rats were prewarmed mildly to increase TT during isoflurane exposure. In the high temperature group (n=6), rats were prewarmed enough to prevent a TT increase during isoflurane exposure.

Results:  There was a highly significant correlation between TT and TF latency, that is, TF latency decreased as TT increased. In the low temperature group, there was a significant increase in TT during isoflurane exposure, while an increase in TF latency did not reach statistical significance. Tail‐flick latency corrected by a change in TT showed a significant increase. In the high temperature group, TF latency increased significantly during isoflurane exposure without an increase in TT.

Conclusions:  Isoflurane inhalation can induce an increase in TT, which can obscure its antinociceptive action as evaluated by a TF test. Monitoring TT during a TF test is important to efficiently evaluate the antinociceptive action of volatile anesthetics.
In‐hospital cardiopulmonary resuscitation: organization, management and training in hospitals of different levels of care
Authors: Skrifvars M. B. , Castrén M. , Kurola J. , Rosenberg P. H.
Published: March 2003

Background: During recent years in‐hospital cardiopulmonary resuscitation (CPR) management has received much attention. This can be attributed to the Utstein model for in‐hospital CPR developed in 1997. The present status of in‐hospital resuscitation management in Finnish hospitals is not known. Therefore, a study was designed to describe the organization of training and clinical management of CPR in Finnish hospitals of different levels of care.

Methods: In the summer of 2000, we performed a cross‐sectional mail survey throughout Finland, including all district, central and university hospitals. The questionnaire outlined in detail in‐hospital resuscitation management and training. For analysis the hospitals were divided into primary, secondary and tertiary groups, depending on levels of care.

Results: Most hospitals (72%) reported having a physician or a nurse in charge of resuscitation management and training. Training in advanced life support was more common among nurses (80%) than among physicians (53%). Suprisingly, a majority of respondents (75%) reported that they felt training in CPR was insufficient. On the general wards and on wards treating cardiac patients, defibrillation was in most cases performed by a physician (91% and 51%, respectively), and less often by a nurse (16% and 31%, respectively). In the secondary and tertiary hospitals cardiac arrest was managed by a cardiac arrest team (53% and 62%, respectively) and in the primary hospitals by the ward physician (56%), anesthesiologist or emergency physician on call (44%). Most hospitals used do‐not‐resuscitate orders (83%) but only 33% of the hospitals had a unified style of notation. Systematic data collection was practised in 55% of hospitals, predominantly by using a model of their own. Only a few hospitals (11%) used the in‐hospital Utstein model.

Conclusion: Our study showed that more attention needs to be paid to CPR management in Finnish hospitals. At present, 25% of hospitals do not have an appointed physician or nurse in charge of organizing CPR management. The study also revealed a lack of regular organized training in resuscitation for physicians. Fiftyfive per cent of hospitals practise systematic data collection, but only 11% according to the Utstein template; and without which further quality assurance is difficult.
Microvascular changes during anesthesia: sevoflurane compared with propofol
Authors: Bruegger D. , Bauer A. , Finsterer U. , Bernasconi P. , Kreimeier U. , Christ F.
Published: March 2003

Background: We have developed a non‐invasive computer‐assisted venous congestion plethysmograph to measure the microvascular parameters in the lower limbs. This enables the assessment of microvascular changes following the induction of standardized anesthesia with either sevoflurane or propofol.

Methods: In a prospective randomized trial we measured the capillary filtration coefficient (CFC), isovolumetric venous pressure (Pvi), an index of the balance of Starling forces, and limb blood flow 24 h preoperatively, immediately after induction of anesthesia and on the 1st and 2nd postoperative day. Anesthesia was maintained with either 1.0% sevoflurane and 5 µg/kg/h remifentanil or propofol (3 mg/kg/h), and 5 µg/kg/h remifentanil in 20 female patients undergoing breast surgery.

Results: Preoperatively we found no significant differences between the mean CFC values of the sevoflurane group (3.7±0.3 ml/min 100 ml tissue/mmHg × 10−3=CFCU) and the propofol group (3.5±0.3 CFCU). In the sevoflurane group CFC decreased significantly to 2.9±0.2 CFCU, whereas it was unchanged in the propofol group. Both groups revealed a significant reduction in Pvi during steady‐state anesthesia. Limb blood flow remained unchanged. There was an overall significant positive correlation between the perioperative fluid substitution and the difference between the preoperative and intraoperative CFC values (r = 0.64, P<0.01).

Conclusion: The decreased CFC in response to sevoflurane may result in less extravasation of fluids into the interstitial space, thereby reducing intraoperative fluid requirements. These data suggest that sevoflurane may be the preferred anesthetic agent in subjects susceptible to large intraoperative fluid shifts.
Atracurium and vecuronium block nicotine‐induced carotid body chemoreceptor responses
Authors: Jonsson M. , Kim C. , Yamamoto Y. , Runold M. , Lindahl S. G. E. , Eriksson L. I.
Published: March 2003

Background: Vecuronium depresses carotid body chemosensitivity during hypoxia. We hypothesized that this is caused by inhibition of cholinergic transmission of the carotid body.

Methods: The carotid body with its sinus nerve was removed en bloc from thiopentone‐anaesthetized adult male New Zealand rabbits and perfused in vitro with modified Tyrodes buffer solution at constant perfusion pressure, temperature, a buffer pH of 7.4 and normocapnia. Chemoreceptor discharge and spike frequencies (fx) were recorded from the whole sinus nerve after administration of 500 µg nicotine, given as duplicated controls and thereafter following 30 min perfusion of equipotent concentrations of atracurium (28.1 µM) or vecuronium(10 µM), after 30 min of neostigmine perfusion (9.2 µM) and finally after 30 min wash‐out with buffer solution only. A short‐lasting hypoxic test was performed before and at the end of the experimental period to confirm the responsiveness and validity of the preparation.

Results: Atracurium (n = 7) and vecuronium (n = 6) reduced chemoreceptor responses to nicotine by 70 ± 30% and 66 ± 19% (SEM) (P<0.05). Chemoreceptor discharges showed full recovery after neostigmine in the atracurium group and partial recovery in the vecuronium group (P<0.05). Finally, after wash‐out the chemoreceptor responses to nicotine had fully recovered in both groups.

Conclusion: Atracurium and vecuronium in equipotent concentrations block nicotine‐induced chemoreceptor responses of the carotid body.
Effect of CO2 pneumoperitoneum on ventilation‐perfusion relationships during laparoscopic cholecystectomy
Authors: Andersson L. , Lagerstrand L. , Thörne A. , Sollevi A. , Brodin L‐Å. , Odeberg‐Wernerman S.
Published: March 2003

Background: Previous studies have shown that pneumoperitoneum transiently reduces venous admixture as assessed by a calculation based on the shunt formula, and increases arterial oxygen tension (PaO2) in patients without heart or lung disease. The aim of the present study was to further explore the relationship between ventilation‐perfusion (V˙A/Q˙) before and during pneumoperitoneum by using the multiple inert gas technique.

Methods: Nine patients without heart or lung disease (ASA I), with a mean age of 42 years, scheduled for laparoscopic cholecystectomy were included. After premedication and induction of anaesthesia, radial artery and pulmonary artery catheters were introduced percutaneously. The V˙A/Q˙ relationships were evaluated by the multiple inert gas elimination technique before and during pneumoperitoneum to obtain a direct measure of the pulmonary shunt.

Results: Induction of pneumoperitoneum decreased the pulmonary shunt from 5.8 (4.5) to 4.1 (3.2)% (P<0.05) and increased PaO2 from 21.7 (5.9) to 24.7 (4.8) kPa (P<0.01). During surgery, the shunt increased from 3.2 (2.8) to 5.2 (3.4)% to the same level as before pneumoperitoneum induction. No area with low V˙A/Q˙ was seen. Dead space ventilation amounted to 20.0 (1.2)% in the supine position and did not change during the investigation.

Conclusions: In patients without heart or lung disease, pneumoperitoneum at an intra‐abdominal pressure level of 11–13 mmHg causes a transient reduction of the pulmonary shunt. The mechanisms underlying the present finding remain to be elucidated.
Bicarbonate attenuates intracellular acidosis
Authors: Nielsen H. B. , Hein L. , Svendsen L. B. , Secher N. H. , Quistorff B.
Published: March 2003

Background: This study was prompted by concern that administration of bicarbonate for correction of lactate acidosis aggravates a low intracellular pH (pHi). In healthy subjects we evaluated skeletal muscle pHi using 31P‐magnetic resonance spectroscopy during 5‐minute rhythmic handgrip to provoke intracellular acidosis.

Methods: Subjects were randomized to treatment with bicarbonate or saline infused intravenously in a cross‐over study design with 1 h between trials.

Results: In response to rhythmic handgrip, muscle venous O2 hemoglobin saturation decreased from 51 ± 4% to 36 ± 2% and lactate increased from 1.0 ± 0.1 to 4.9 ± 0.5 mmol/l with a reduction in pH from 7.43 ± 0.01–7.23 ± 0.01 (P<0.05). pHi decreased from 7.06 ± 0.02–6.36 ± 0.08 (P<0.05). Infusion of bicarbonate increased the arterial blood concentration from 26 ± 1 to 39 ± 1 mmol/l (P<0.05). The arterial CO2 partial pressure decreased from 5.6 ± 0.2 to 5.2 ± 0.3 kPa during rhythmic handgrip, whereas it increased to 5.9 ± 0.2 kPa (P<0.05) during infusion of bicarbonate. Bicarbonate treatment also increased pH of arterial and venous blood (7.55 ± 0.01 vs. 7.44 ± 0.02 and 7.31 ± 0.01 vs. 7.23 ± 0.02, respectively; P<0.05). In the last min of rhythmic handgrip the decrease in pHi was attenuated by the administration of bicarbonate (6.60 ± 0.11 vs. 6.40 ± 0.12; P<0.05).

Conclusion: During exercise‐induced metabolic acidosis, intravenous administration of bicarbonate increased the buffering capacity of blood and attenuated the decrease in intracellular muscle pH, although there was a small increase in the arterial carbon dioxide pressure.
Effect of alkalinization and/or hyaluronidase adjuvancy on a local anesthetic mixture for sub‐Tenon's ophthalmic block
Authors: Moharib M. M. , Mitra S. , Rizvi S. G.
Published: March 2003

Background and objectives: pH adjustment and/or addition of hyaluronidase to local anesthetic drugs decrease the time to onset and prolong the duration of regional anesthetic techniques for ocular surgery. The objective of this study was to investigate whether these factors are effective also in sub‐Tenon's block.

Methods: Sixty patients were randomly assigned to four groups in a double blind, prospective fashion, and received 5.125 ml mixtures as follows: 2.5 ml lignocaine 2%, 2.5 ml bupivacaine 0.5% and 0.125 ml isotonic saline (group LB); 2.5 ml lignocaine 2%, 2.5 ml bupivacaine 0.5%, 15 IU hyaluronidase/ml and 0.125 ml isotonic saline (group LBH); 2.5 ml lignocaine 2%, 2.5 ml bupivacaine 0.5% and 0.125 ml sodium bicarbonate 8.4% (group LBpH); and 2.5 ml lignocaine 2%, 2.5 ml bupivacaine 0.5%, 15 IU hyaluronidase/ml and 0.125 ml sodium bicarbonate 8.4% (group LBHpH). This measurement was based on one quadrant sub‐Tenon's block. Akinesia was assessed every 30 s.

Results: No statistically significant differences were found between the groups regarding mean times to onset and to complete akinesia. Group LBH displayed a significantly lower frequency of patients experiencing pain and a lower need for rescue medication during surgery than the other groups.

Conclusion: pH adjustment and/or addition of hyaluronidase to a mixture of lignocaine and bupivacaine did not shorten the time to onset of akinesia following sub‐Tenon's technique. However, the addition of hyaluronidase was associated with a lower fraction of patients experiencing pain during surgery.
Coiling of lumbar epidural catheters
Authors: Lim Y. J. , Bahk J. H. , Ahn W. S. , Lee S. C.
Published: March 2003

Background: The difficulties in threading an epidural catheter to vertebral levels remote to the puncture level have been well documented. This study was undertaken to determine the length that a single orifice epidural catheter can be threaded into the lumbar space without coiling (coiling length), and whether this is affected by the direction of the epidural needle bevel.

Methods: Forty‐five young male patients scheduled for surgery under epidural analgesia were enrolled. The epidural space was identified using a midline approach at the L2−3 or L3−4 interspace with the loss of resistance to air technique. A 19‐G single‐orifice epidural catheter (Flextip PlusTM, Arrow International, Inc, Reading, PA, USA) was inserted through a Tuohy needle oriented either cephalad (n=20) or caudad (n=25). During insertion, the path and the position of the catheter tip was determined by fluoroscopy using iohexol dye.

Results: The median coiling length was 2.8 cm, ranging from 1.0 to 8.0 cm. Only 13% of epidural catheters could be threaded 4 cm beyond the tip of the needle without coiling. No significant difference was found in coiling length between the cephalad group (2.9 cm) and the caudad group (2.5 cm).

Conclusion: This study demonstrates that coiling length is independent of whether the bevel of the Tuohy needle is directed cephalad or caudad. We recommend that an optimal insertion depth of an end‐hole single orifice catheter is 3 cm.
Epidural buprenorphine in management of pain in multiple rib fractures
Authors: Govindarajan R. , Bakalova T. , Michael R. , Abadir A. R.
Published: March 2003

Background: Pain from multiple rib fractures may affect pulmonary function, morbidity, and length of stay in the intensive care units. This study describes some clinical characteristics of epidural buprenorphine, a lipophilic and partial opiate agonist with a higher µ receptor affinity than morphine, in combating the pain in multiple rib fractures.

Methods: The study was conducted prospectively over a 15‐month period. A total of 27 patients admitted to the hospital with multiple rib fractures were studied. Buprenorphine at a concentration of 0.3 mg in 5–10 ml normal saline was administered epidurally, twice daily the first 24 h, thereafter once daily. Ventilatory function tests (including vital capacity, tidal volume, respiratory rate, and minute volume) and assessment of pain intensity using a simple, categorical, verbal rating scale were obtained before and after institution of analgesia. Any nausea, vomiting, hypotension, urinary retention, respiratory depression or pruritis were recorded.

Results: We found a significant improvement in ventilatory function tests during the 1st, 2nd, and 3rd day after epidural analgesia when compared with the preanalgesia levels (P < 0.001). Changes in the verbal rating scale demonstrated that epidural buprenorphine was associated with marked improvement in pain at rest and pain during coughing and deep breathing. None of our patients developed hypotension (<10% of the baseline), urinary retention or respiratory depression. Nausea, vomiting, and mild pruritis were the only reported complications.

Conclusions: Epidurally introduced narcotic, like buprenorphine in saline, has been found to be effective in our study to achieve adequate analgesia in treatment of patients with multiple rib fractures. In addition, this methodology of pain relief eliminates the costly delivery system and early discharge, and allows walking epidurals and follow‐up on outpatient basis.
Improved long‐lasting postoperative analgesia, recovery function and patient satisfaction after inguinal hernia repair with inguinal field block compared with general anesthesia
Authors: Aasbø V. , Thuen A. , Ræder J.
Published: March 2003

Background: Inguinal hernia repair is a common surgical procedure, and different types of anesthetic techniques are in use. We wanted to test if preoperative inguinal field block (IFB) with ropivacaine would provide benefits in the postoperative period compared with general anesthesia and wound infiltration.

Methods: Sixty patients scheduled for inguinal hernia repair were randomized to receive general anesthesia with wound infiltration postoperatively, or inguinal field block (IFB) before surgery, with no or only light sedation intraoperatively. General anesthesia was induced with midazolam, fentanyl and propofol, maintained with propofol and alfentanil, and supplemented with nitrous oxide in oxygen through a laryngeal mask. The IFB was performed by an anesthesiologist, with 50–60 ml ropivacaine and 5 mg/ml with a dedicated technique.

Results: All significant differences were in favor of the IFB group: less pain (visual analog scale, verbal pain score) postoperatively and until day 7, faster mobilization with less pain, lower analgesic consumption, and higher patient satisfaction.

Conclusion: Preoperative inguinal field block for hernia repair provides benefits for patients in terms of faster recovery, less pain, better mobilization and higher satisfaction throughout the whole first postoperative week.
Plasma cholinesterase activity and duration of action of mivacurium in phenotypically normal patients
Authors: Østergaard D. , Ibsen M. , Skovgaard L. , Viby‐Mogensen J.
Published: March 2003

Background: The short duration of action of mivacurium is due to its rapid hydrolysis by plasma cholinesterase (pChe). In patients with normal phenotype, low pChe activity because of, for instance, disease or intake of drugs may prolong the duration of action of mivacurium. The purpose of this study was to evaluate the relationship between pChe activity and the duration of action of mivacurium 0.2 mg/kg in phenotypically normal patients.

Material: Forty‐three adult patients with normal pChe phenotype and low or normal pChe activity, undergoing a variety of surgical procedures were included in the study with their informed consent and Ethics Committee approval. The neuromuscular block was monitored using TOF stimulation every 12 s and mechanomyography. The time to reappearance of the first response to TOF stimulation was measured.

Results: The patients pChe activities ranged from 45 to 1272 U/l (normal range 660–1620 U/l) and the time to first response to TOF from 8.1 to 62.7 min. An inverse relationship between enzyme activity and duration of action of mivacurium was found. The relationship was described by the equation: log10 (time) =α‐ β log10 (pChe), where α (SD) is 2.547 (0.186) and β (SD) 0.454 (0.069).

Conclusion: In patients with phenotypically normal pChe, prediction of the duration of action of mivacurium is possible from the patients actual pChe activity. In patients with pChe activities below the normal range, the time to reappearance of the first response to TOF stimulation may vary from 10 to 180 min Only patients with pChe activities <220 U/l had a significantly prolonged duration of action of mivacurium.
Comparative effects of xenon and nitrous oxide on diaphragmatic contractility in dogs
Authors: Hoshi T. , Fujii Y. , Toyooka H.
Published: March 2003

Background:  Xenon at two different concentrations (30%, 60%) has no effect on diaphragmatic contractility. This study was undertaken to compare the effects of xenon and nitrous oxide (N2O), a commonly used and well‐established gas anesthetic, on diaphragmatic contractility in dogs.

Methods:  Twenty‐one pentobarbitone‐anesthetized dogs were randomly divided into three groups of seven each: group 1 received xenon 30% (0.25 MAC) in oxygen; group 2 received N2O 47% (0.25 MAC) in oxygen; and group 3 received N2O 60% (0.32 MAC) in oxygen. Diaphragmatic contractility was assessed by transdiaphragmatic pressure (Pdi) at low‐ (20‐Hz) and high‐frequency (100‐Hz) stimulation, after maintaining 60 min of stable condition. The integrated electrical activity of diaphragm (Edi) to each stimulus was measured.

Results:  With an inhalation of xenon 30%, N2O 47%, or N2O 60%, Pdi and Edi at both stimuli did not change. No difference in Pdi or Edi was observed among the groups.

Conclusion:  When used at clinical concentration, xenon or N2O does not affect contractility and electrical activity of the diaphragm in dogs.
Intraocular pressure more reduced during anesthesia with propofol than with sevoflurane: both combined with remifentanil
Authors: Schäfer R. , Klett J. , Auffarth G. , Polarz H. , Völcker H. E. , Martin E. , Böttiger B. W.
Published: March 2003

Background:  Short‐acting anesthetic agents are suitable and commonly used in ocular surgery. Propofol and remifentanil are known to reduce intraocular pressure (IOP), but no information is available regarding the effects of sevoflurane combined with remifentanil on IOP.

Methods:  Therefore, a prospective, randomized study was conducted to compare the effects on IOP of two different anesthetic techniques: one based on a total intravenous anesthesia with propofol (Group P, bolus 1.5–2.0 mg/kg, maintenance 3.0–7.0 mg/kg/h); and the other based on sevoflurane (Group S, inhalational induction, end‐tidal concentration 0.7–1.2 vol.%). An infusion of remifentanil (10 µg/kg/h) was used with both techniques. In ASA I–III patients with normal IOP undergoing elective cataract surgery, using an applanation tonometer, IOP was measured contralateral to the operated eye at nine predefined time points before, during and after anesthesia.

Results:  The two groups (n=20 each) were comparable with regard to demographic data and hemodynamic variables. Baseline IOP was 14.2±2.8 mmHg (Group P) and 14.1±2.4 mmHg (Group S; NS). During and following the induction of anesthesia, IOP was reduced in both groups. Intraocular pressure was significantly lower in Group P (6.0±3.2 mmHg) than in Group S (8.9±3.4 mmHg) during the induction of anesthesia.

Conclusion:  In patients undergoing cataract surgery under general anesthesia with tracheal intubation, anesthetic regimens with propofol as well as with sevoflurane, both combined with remifentanil, decrease IOP significantly. The decrease in IOP was significantly more pronounced in the propofol group than in the sevoflurane group.
Resistance to vecuronium in a term neonate
Authors: Sarti A. , Cergol M. , Scarpa R. , Agosti A. , Runti G.
Published: March 2003

We report a case of resistance to curarization in a term neonate undergoing surgery. The dosage of vecuronium required to obtain satisfactory muscular blockade and cessation of spontaneous breathing efforts was more than 10‐fold the normal one. The operation was delayed for 90 min The mechanism of this marked resistance is unknown, but some possible hypotheses are presented, focusing on the neonate's poor intrauterine growth and an abnormality in pharmacodynamics.
Repeat cesarean section in a morbidly obese parturient: a new anesthetic option
Authors: Kuczkowski K. M. , Benumof J. L.
Published: March 2003

Combined spinal epidural anesthesia (CSEA) has become an increasingly popular anesthetic technique for repeat cesarean section. However, the advantages of this technique have not routinely been available to morbidly obese patients because of the lack of an appropriately long needle. We present a case of a morbidly obese parturient who underwent repeat cesarean section under CSEA conducted with the recently introduced (and commercially available) CSEA needle set, specifically designed for morbidly obese patients.
When is an anesthesiologist needed in a helicopter emergency medical service in northern Norway?
Authors: Nielsen E. W. , Ulvik A. , Carlsen A. W. , Rannestad B.
Published: March 2003

Background: A national air ambulance service, including helicopters and airplanes, was implemented in Norway in 1988. The main intention was to offer advanced medical services when needed. All helicopters are manned by anesthesiologists. Catchment areas for the 11 helicopters span from cities to scarcely populated areas, particularly in the north. Our aim was to assess what proportion of ambulance missions carried out by the rescue helicopter in Bodø, northern Norway, delivered advanced medical treatment needing the skills of an anesthesiologist.

Methods: Flight and ambulance records (n = 2078) from 1988 and 1990–98 (10 years) were analyzed retrospectively. Inter‐hospital transfers (n = 147) and search‐ and rescue missions (n = 332) were not included. According to the level of medical treatment given missions were categorized into three groups (A, B and C). Treatment in groups A and B would not require an anesthesiologist.

Results: Two thousand and seventy‐eight ambulance missions carried 2166 patients (114 per 100 000 per year). Median take‐off and on‐scene times were 29 and 55 min, respectively. Seven hundred and fifty‐five patients (35%) suffered from cardiovascular disease, 495 (23%) were injured and 250 (12%) were parturients. One hundred and seven patients (5.0%) received advanced prehospital emergency treatment requiring an anesthesiologist. Forty‐five of the 107 patients survived to discharge from hospital, amongst whom 28 had received intravenous nitroglycerin for angina or suspected myocardial infarction.

Conclusion: In our rural area, with a widely scattered population, 95% of patients received medical treatment not requiring an anesthesiologist. A selective use of the anesthesiologist seems indicated.
Patients' experiences with multiple stimulation axillary block for fast‐track ambulatory hand surgery
Authors: Koscielniak‐Nielsen Z. J. , Rotbøll‐Nielsen P. , Rassmussen H.
Published: March 2003

Background: Ambulatory axillary block by multiple nerve stimulation (MNS) is effective and time efficient, but may be rejected by patients because of block pain. This prospective study assessed patients' anxiety and acceptance of this block, identified which of the components of blocking procedure is most painful (i.v. line insertion, repeated needle passes, local anesthetic injection, or electrical stimulation) and recorded patients' anesthetic preferences for the future hand surgery.

Methods: Upon arrival at the day unit, 100 unpremedicated adult patients without previous experience of peripheral nerve stimulation indicated on the visual analog scale (VAS; 0–100) their anxiety about the block. The blocking procedure was then explained step‐by‐step. After inserting the i.v. line and freezing the skin in axilla, four terminal nerves (musculocutaneous, median, ulnar, radial) were electrolocated using an initial current of 2 mA and a target current of 0.1–0.5 mA. Pain caused by the individual components of blocking procedure was assessed on VAS before the start of surgery. On the day after the operation, the patients reassessed their anxiety for the next axillary block and indicated which anesthetic method (block alone, block plus sedation, or general anesthesia) they would prefer for the future hand surgery.

Results: Before the block, 59 patients admitted being anxious about regional block (median anxiety VAS=27), compared with 42 patients (anxiety VAS=10) postoperatively: P<0.01. Median intensity of electrical stimulation pain was significantly higher (VAS=16) than pain of local anesthetic injections (VAS=8), i.v. line insertion (VAS=6) and multiple needle passes (VAS=5). However, only 53 patients categorized electrolocation as painful. Twenty‐seven reported discomfort but not pain, and 20 patients described the sensation as ‘funny’ or ‘strange’. None of the patients had surgical pain during operation. Mean duration of surgery was 77 min, and of hospital stay 166 min. Ninety‐eight patients would choose the same block for the future hand surgery, 13 of which would like sedation before the block, and two patients did not wish to be awake during any surgery. Ninety‐five patients were satisfied with fast‐tracking.

Conclusions: Fear of block pain is diminished after experiencing the blocking procedure. Electrical stimuli was perceived as painful by 53% of patients, and this pain was more intense than with other block components. The majority of our patients would choose axillary block without sedation for future hand surgery and are satisfied with fast‐tracking.
Survey of epidural analgesia management in general intensive care units in England
Authors: Low J. H. S.
Published: March 2003

Background: The management of epidural analgesia is controversial. Many intensive care unit (ICU) patients may benefit from this form of analgesia but have one or more contraindications to its use. Sepsis, coagulopathy, insertion in a sedated, ventilated patient, and lack of consent are common problems in ICU patients. Little has been published to help guide practice in this area. I wished to establish the current practice of the management of epidural analgesia in general ICUs in England when relative or absolute contraindications occur, in order to determine the current standard of care for placement and use of epidural analgesia in ICU patients.

Methods: A postal questionnaire survey of the management of epidural analgesia in critically ill patients was sent to the named clinical director of all (216) general ICUs in England.

Results: Responses were received from 159 (75%) units: 89% of responding units use epidural analgesia but only 51(32%) have a written policy covering its use. Anesthetists or intensivists with an anesthetic background sited all epidural catheters; 68% of units would not site an epidural in a patient with positive blood cultures; but only 52% considered culture negative sepsis (systemic signs of sepsis with no organism isolated) to be a contraindication. Neither lack of consent nor the need for anticoagulation after the catheter had been sited were considered contraindications to inserting an epidural catheter by the majority of respondents. Although 71% of the units would remove an epidural catheter if a patient developed positive blood cultures after it had been sited, the majority of the ICUs did not consider culture negative sepsis and the need for anticoagulation contraindications to maintain a previously sited epidural.

Conclusions: Practice varied considerably with little consensus. Although all the respondents use epidural analgesia in critically ill patients, the indications and contraindications to epidural analgesia remain controversial, and further research is required to help define the role of epidural analgesia in this high‐risk group.
Effect of axillary brachial plexus blockade on baroreflex‐induced skin vasomotor responses: assessing the effectiveness of sympathetic blockade
Authors: Szili‐Torok T. , Paprika D. , Peto Z. , Babik B. , Bari F. , Barzo P. , Rudas L.
Published: March 2003

Background: The combination of laser Doppler flowmetry and non‐invasive blood pressure monitoring allows the continuous observation of cutaneous vascular resistance (CVR). Continuous recording of unmodulated skin blood flow (SBF) is very sensitive to artefacts, rendering the method unreliable. In contrast, intermittent short lasting challenges of the CVR by cardiovascular autonomic reflexes may provide information about the responsiveness of the sympathetic nervous system in the skin.

Methods: Eleven patients with below‐wrist hand surgery (six males and five females; aged 35.2±7.1 years) performed Valsalva maneuver following axillary blockade. Skin blood flow was continuously monitored on the forearm of the side axillary blockade, as well as on the contra‐lateral forearm, which was used as the control. The responses were expressed as changes compared with the baseline level derived from a resting period of 30 s. The maximal change in CVR was determined during the late strain phase of the Valsalva maneuver on both sides. For numerical comparison the change in CVR on the axillary blockade and control sides were simultaneously calculated.

Results: During the Valsalva maneuver a significant increase in CVR was observed on the control side with a maximum value during the late strain phase (baseline 0.18±0.1 and late strain phase 0.42±0.2 relative units; P<0.01). In contrast, only minimal changes were detected on the side of axillary blockade in CVR (baseline 0.17±0.8 and late strain 0.16±0.2 relative units; P=NS).

Conclusions: Our findings support the disputed hypothesis that the human skin microvasculature is involved in baroreflex regulation under thermoneutral conditions. The determination of baroreflex stimulus‐induced microvascular responses may serve as a feasible method for monitoring the effectiveness of sympathetic blockade.
No enhancement of sensory and motor blockade by ketamine added to ropivacaine interscalene brachial plexus blockade
Authors: Lee Il‐Ok , Kim Woo‐Kyung , Kong Myung‐Hoon , Lee Mi‐Kyung , Kim Nan‐Sook , Choi Young‐Seok , Lim Sang‐Ho
Published: March 2003

Background: Ketamine can enhance anesthetic and analgesic actions of a local anesthetic via a peripheral mechanism. The authors' goal was to determine whether or not ketamine added to ropivacaine in interscalene brachial plexus blockade prolongs postoperative analgesia. In addition, we wanted to determine the incidence of adverse‐effects in patients undergoing hand surgery.

Methods: Sixty adults scheduled for forearm or hand surgery under the interscalene brachial plexus block were prospectively randomized to receive one of the solutions of the study. Group P received 0.5% ropivacaine 30 ml, group K received 0.5% ropivacaine 30 ml with 30 mg ketamine, and group C received 0.5% ropivacaine with 30 mg ketamine i.v. Loss of shoulder abduction, elbow flexion, wrist flexion and loss of pinprick in the C4–7 sensory dermatomes were assessed at 1‐min intervals. Adverse‐effects were assessed every 5 min. The duration of the sensory and motor blocks was assessed after operation. Adverse‐effects were also recorded.

Results: The onset time of sensory or motor blockade and the duration of sensory or motor blockade were similar in all groups. Adverse‐effects occurred in 44% of patients in group K and 94% of group C.

Conclusion: This study suggests that 30 mg ketamine added to ropivacaine in the brachial plexus block does not improve the onset or duration of sensory block, but it does cause a relatively high incidence of adverse‐effects. These two findings do not encourage the use of ketamine with local anesthetics for brachial plexus blockade.
Nasal CPAP therapy: effects of different CPAP levels on pressure transmission into the trachea and pulmonary oxygen transfer
Authors: Kindgen‐Milles D. , Buhl R. , Loer S. A. , Müller E.
Published: March 2003

Background: Nasal continuous positive airway pressure (nCPAP) is considered useful for prophylaxis and treatment of respiratory complications following major thoracic surgery. It is unknown, however, which CPAP levels are required to avoid alveolar derecruitment and to consistently improve pulmonary oxygen transfer in patients following thoracotomy. We therefore studied the effects of different nCPAP levels on pressure transmission into the trachea as well as on pulmonary oxygen transfer.

Methods:   In 10 consecutive patients after cardiac or thoracic vascular surgery, following extubation in the ICU, nCPAP was generated by means of a high‐flow gas source and applied randomly at levels of 5 or 10 cm H2O. Airway pressure was recorded continuously in the nasal mask and the trachea. The PaO2/FiO2ratio was calculated from the tracheal oxygen concentration, and PaO2 was determined while breathing at an ambient and elevated airway pressure. Haemodynamic variables (heart rate, arterial blood pressure, central venous pressure) were also recorded.

Results:   Mean pressures in the nasal mask were 5.4±0.1 and 9.7±0.3 cm H2O. Corresponding tracheal pressures were 2.8±1.0 vs. 7.2±1.1 cm H2O (P=0.007). With higher mask pressure, the fraction of pressure transferred from the nasal mask into the trachea was larger (0.75±0.03 vs. 0.52±0.05; P=0.04), and tracheal pressures remained positive during the entire respiratory cycle in all patients. In contrast, with 5.4 cm H20, negative pressure changes during inspiration occurred in five out of 10 patients. The PaO2/FiO2 ratio increased from 183±53 (ambient pressure) to 199±74 (nCPAP 5.4 cm H2O; P=0.25) and to 333±54 (nCPAP 9.7 cm H2O; P=0.003). Nasal CPAP did not alter hemodynamics.

Conclusion: Nasal CPAP is an effective non‐invasive means of increasing tracheal and thus intrathoracic pressure without adverse hemodynamic effects. Only mask pressures of 9–10 cm H2O were sufficient to consistently improve pulmonary oxygen transfer in patients following thoracotomy.
Severe ARDS may cause right heart failure with extreme hepatomegaly but without hepatic failure
Authors: Søreide E. , Harboe S. , Søndenaa K.
Published: March 2003

A young trauma patient developed severe adult respiratory distress syndrome (ARDS), right heart failure, hepatic congestion and an extreme hepatomegaly but no hepatic failure. The patient needed 100% oxygen during ventilatory support for 80 days and was weaned from the ventilator after more than 100 days. The hepatomegaly gradually disappeared. Four months after the injury, the anatomical shape of the lungs, heart and liver were normalized. This case illustrates that severe ARDS may cause right heart failure and extreme hepatomegaly due to venous congestion in the liver and spleen, but without hepatic failure.
Tracheal esophageal combitube: a useful airway for morbidly obese patients who cannot intubate or ventilate
Authors: Della Puppa A. , Pittoni G. , Frass M.
Published: March 2003

The tracheal esophageal combitube has been successfully used in many difficult airway circumstances. We report the dramatic case of a morbidly obese patient with a well‐known difficult airway who was successfully rescued from a cannot ventilate–cannot intubate situation in our critical care unit by using the tracheal esophageal combitube. Surgical tracheostomy was performed while she was mechanically ventilated through the tracheal esophageal combitube. The tracheal esophageal combitube is a very important device that should be kept available in all cases of morbidly obese airway management.
Volume‐targeted therapy of increased intracranial pressure: the Lund concept unifies surgical and non‐surgical treatments
Authors: Grände P.‐O. , Asgeirsson B. , Nordström C.‐H.
Published: March 2003

Opinions differ widely on the various treatment protocols for sustained increase in intracranial pressure (ICP). This review focuses on the physiological volume regulation of the intracranial compartments. Based on these mechanisms we describe a protocol called ‘volume‐targeted’ (‘Lund concept’) for treatment of increased ICP.

The driving force for transcapillary fluid exchange is determined by the balance between effective transcapillary hydrostatic and osmotic pressures. Fluid exchange across the intact blood–brain barrier (BBB) is counteracted by the low permeability to crystalloids (mainly Na+ and Cl–) combined with the high osmotic pressure (5500 mmHg) on both sides of the BBB. This contrasts to most other capillary regions where the osmotic pressure is mainly derived from the plasma proteins (approximately 25 mmHg). Accordingly, the level of the cerebral perfusion pressure (CPP) is of less importance under physiological conditions. In addition cerebral intracapillary hydrostatic pressure (and cerebral blood flow) is physiologically tightly autoregulated, and variations in systemic blood pressure are generally not transmitted to these capillaries.

If the BBB is disrupted, transcapillary water transport will be determined by the differences in hydrostatic and colloid osmotic pressure between the intra‐ and extracapillary compartments. Under these pathological conditions, pressure autoregulation of cerebral blood flow is likely to be impaired and intracapillary hydrostatic pressure will depend on variations in systemic blood pressure.

The volume‐targeted ‘Lund concept’ can be summarized under four headings: (1) Reduction of stress response and cerebral energy metabolism; (2) reduction of capillary hydrostatic pressure; (3) maintenance of colloid osmotic pressure and control of fluid balance; and (4) reduction of cerebral blood volume. The efficacy of the protocol has been evaluated in experimental and clinical studies regarding the physiological and biochemical (utilizing intracerebral microdialysis) effects, and the clinical experiences have been favorable.
Immune response in asymptomatic smokers
Authors: Zeidel A. , Beilin B. , Yardeni I. , Mayburd E. , Smirnov G. , Bessler H.
Published: March 2003

Background:  It has been demonstrated that cigarette smoking affects the immune system. Impairment of alveolar mononuclear cell function, described previously, may contribute to the higher rate of postoperative respiratory infections. However, increased susceptibility of smokers to infections of other origin (e.g. wound‐related) implies that tobacco effect is not restricted to the respiratory immune competent cells. The present study was designed to investigate the systemic effect of tobacco smoking as it exerted on blood‐derived immune cells. We measured systemic cytotoxic activity of natural killer cells, production of pro‐ and anti‐inflammatory cytokines by blood mononuclear cells and their proliferation in response to mitogens. To minimize the immunosuppressive effect of other smoke‐related factors, the smokers with chronic obstructive pulmonary disease (COPD) were excluded from this study.

Methods:  Peripheral blood mononuclear cells (PBMC) from 24 chronic asymptomatic smokers, and 28 controls, age and gender matched, were isolated and incubated in vitro with lipopolysaccharide (LPS) or phytohemagglutinin (PHA) to induce secretion of IL‐1β, IL‐1ra, IL‐6, IL‐10, TNFα and IL‐2, respectively, from mononuclear cells. The level of the cytokines in the supernatants was measured using ELISA kits. The proliferative response to the mitogens PHA and concanavalin A (ConA) was evaluated by 3H‐thymidine incorporation and NK cell cytotoxicity by 51Cr release assay.

Results: Mononuclear cells from smokers showed increased production of the pro‐inflammatory cytokines IL‐1β, IL‐6 and TNFα and enhanced proliferative response to mitogens as compared to non‐smoking population.

The secretion of IL‐2 and the anti‐inflammatory cytokines IL‐1ra and IL‐10 was similar in both groups. NK cell cytotoxic activity was suppressed in the smokers.

Conclusion: Cigarette smokers without chronic obstructive pulmonary disease (COPD) exhibit impaired NK cytotoxic activity in peripheral blood and unbalanced systemic production of pro‐ and anti‐inflammatory cytokines. These changes may serve as predisposing factors for respiratory and systemic infections in the postoperative period and should alert an anesthetist during perioperative management.
Extubation after breathing trials with automatic tube compensation, T‐tube, or pressure support ventilation
Authors: Haberthür C. , Mols G. , Elsasser S. , Bingisser R. , Stocker R. , Guttmann J.
Published: March 2003

Background: Automatic tube compensation (ATC) is a new option to compensate for the pressure drop across the endotracheal or tracheostomy tube (ETT), especially during ventilator‐assisted spontaneous breathing. While several benefits of this mode have so far been documented, ATC has not yet been used to predict whether the ETT could be safely removed at the end of weaning, from mechanical ventilation.

Methods: We undertook a systematic trial using a randomized block design. During a 2‐year period, all eligible patients of a medical intensive care unit were treated with ATC, conventional pressure support ventilation (PSV, 5 cmH2O), or T‐tube for 2‐h. Tolerance of the breathing trial served as a basis for the decision to remove the endotracheal tube. Extubation failure was considered if reintubation was necessary or if the patient required non‐invasive ventilatory assistance (both within 48 h).

Results and conclusions: After the inclusion of 90 patients (30 per group) we did not observe significant differences between the modes. Twelve patients failed the initial weaning trial. However, half of the patients who appeared to fail the spontaneous breathing trial on the T‐tube, PSV, or both, were successfully extubated after a succeeding trial with ATC. Extubation was thus withheld from four and three of these patients while breathing with PSV or the T‐tube, respectively, but to any patient breathing with ATC. It seems that ATC can be used as an alternative mode during the final phase of weaning from mechanical ventilation. Furthermore, this study may promote a larger multicenter trial on weaning with ATC compared with standard modes.
Antibiotic prescription practices, consumption and bacterial resistance in a cross section of Swedish intensive care units
Authors: Walther S. M. , Erlandsson M. , Burman L. G. , Cars O. , Gill H. , Hoffman M. , Isaksson B. , Kahlmeter G. , Lindgren S. , Nilsson L. , Olsson‐Liljequist B. , Hanberger H. , Icustrama Study Group The
Published: March 2003

Background: The purpose of this work was to study usage of antibiotics, its possible determinants, and patterns of bacterial resistance in Swedish intensive care units (ICUs).

Methods: Prospectively collected data on species and antibiotic resistance of clinical isolates and antibiotic consumption specific to each ICU in 1999 were analyzed together with answers to a questionnaire. Antibiotic usage was measured as defined daily doses per 1000 occupied bed days (DDD1000).

Results: Data were obtained for 38 ICUs providing services to a population of approximately 6 million. The median antibiotic consumption was 1257 DDD1000 (range 584–2415) and correlated with the length of stay but not with the illness severity score or the ICU category. Antibiotic consumption was higher in the ICUs lacking bedside devices for hand disinfection (2193 vs. 1214 DDD1000, p=0.05). In the ICUs with a specialist in infectious diseases responsible for antibiotic treatment the consumption pattern was different only for use of glycopeptides (58% lower usage than in other ICUs: 26 vs. 11 DDD1000,P=0.02). Only 21% of the ICUs had a written guideline on the use of antibiotics, 57% received information on antibiotic usage at least every 3 months and 22% received aggregated resistance data annually. Clinically significant antimicrobial resistance was found among Enterbacter spp. to cephalosporins and among Enterococcus spp. to ampicillin.

Conclusions: Availability of hand disinfection equipment at each bed and a specialist in infectious diseases responsible for antibiotic treatment were factors that correlated with lower antibiotic consumption in Swedish ICUs, whereas patient‐related factors were not associated with antibiotic usage.