Intrathecal atropine to prevent postoperative nausea and vomiting after Cesarean section: a randomized, controlled trial.

BACKGROUND: Postoperative nausea and vomiting (PONV) is a common adverse effect of intrathecal morphine, especially after Cesarean section. This randomized controlled trial investigated the effects of intrathecal administration of a small-dose of atropine on postoperative nausea and vomiting after Cesarean section. METHODS: Parturients with ASA physical status class I-II scheduled for elective Cesarean section and consenting to spinal anesthesia were enrolled. They received 0.5% hyperbaric bupivacaine 12.5 mg, morphine 200 µg and one of the following three solutions: atropine 100 µg intrathecally and saline intravenously; saline intrathecally and atropine 100 µg intravenously; saline only both intravenously and intrathecally. We examined the incidence and severity of PONV, pain ratings and the need for analgesics. RESULTS: We followed 204 parturients. The incidence of PONV was 15%, 37% and 49% in the three groups, respectively (P<0.001). The relative risk reduction for PONV when using intrathecal atropine was 69% vs. placebo and 59% vs. intravenous atropine. No differences were noted in terms of postoperative pain. CONCLUSION: Intrathecal atropine had a significant antiemetic effect, making it a useful adjunct for intrathecal opioid-related PONV.

Continuous lumbar epidural infusion of levobupivacaine: effects of small-or large-volume regimen of infusion.

BACKGROUND: The question of whether the dose, concentration or volume of a local anesthetic solution is the relevant determinant of the spread and quality of post-operative epidural analgesia is still open. In this prospective, randomized, double-blind study, we compared the effects of a large volume-low concentration with a small-volume-high-concentration lumbar epidural infusion of levobupivacaine. METHODS: Seventy patients scheduled for total hip replacement were enrolled. After surgery, patients were randomly allocated to receive a continuous epidural infusion of levobupivacaine (10.5 mg/h) using either 0.125% levobupivacaine infused at 8.4 ml/h (low concentration group, n=35) or 0.75% levobupivacaine infused at 1.4 ml/h (high concentration group, n=35). We blindly recorded the degree of pain relief at rest and during movement every 8 h for the first two post-operative days, as well as hip flexion, motor block, rescue analgesic consumption and adverse events. RESULTS: No difference in pain relief was observed between groups as estimated with the areas under the curve of the verbal Numerical Rating Scale for pain over time, both at rest and during movement. Similarly, there was no difference between groups in hip flexion degree, motor blockade and hemodynamic stability. CONCLUSIONS: Continuous lumbar epidural infusion of 0.75% levobupivacaine was as effective as continuous lumbar epidural infusion of 0.125% levobupivacaine, when administered at the same hourly dose of 10.5 mg, in achieving adequate analgesia both at rest and during movement, without differences in the incidence of hypotension and motor blockade.

Central venous catheters and infections.

The indications to the positioning of central venous catheters (CVCs) are various: parenteral nutrition, chemotherapy, infusion of large amount of fluids or blood products, chronic access for hemodialysis, invasive measurement of hemodynamic variables. Infection is the most important clinical complication associated with the use of CVC, both in terms of incidence and of gravity. Despite the efforts for the optimization of the materials that are more and more biocompatible, the presence of a foreign body in the organism is an ideal substratum for the microbial colonization. The Catheter-Related-Bloodstream-Infections (CRBI) involve a pro-longation of recovery stay, the increase in costs of hospitalization and an increase in morbidity and mortality. The infections are caused by: Staphylococcus aureus and Staphylococcus epidermidis (60%), other bacteria (Enterococ-cus faecalis and Faecium, Pseudomonas aeruginosa; 25%) and among fungi by Candida albicans and Parapsilosis (15%). In order to prevent the CRBI it's important to follow some behavioural norms, both during the positioning of the catheter and in the subsequent assistance to the patient. In case of CRBI it is fundamental to make a sure diagnosis with the positivity for the same pathogen of 2 hemocultures obtained from CVC and from a peripheral vein and then with the microbiological analysis of the tip of the catheter, in order to carry out the specific antibiotic therapy.

Nuclear factor-kappaB as a target of cyclosporin in acute hypovolemic hemorrhagic shock.

BACKGROUND: Cyclosporin is an immunosuppressive drug that blocks Nuclear Factor kappaB (NF-kappaB) activation. We investigated the role of NF-kappaB in acute hypovolemic hemorrhagic (Hem) shock and the effects of cyclosporin in this model of experimental shock. METHODS: Hem shock was induced in male anesthetized rats by intermittently withdrawing blood from an iliac catheter over a period of 20 min (bleeding period) until mean arterial blood pressure (MAP) fell and stabilized within the range of 20-30 mmHg. Two minutes after bleeding cessation, animals received intravenously cyclosporin (1 mg kg(-1)) or its vehicle. Survival rate and survival time were evaluated for 120 min after bleeding was discontinued. Plasma TNF-alpha levels were investigated at different time points after bleeding cessation. Moreover we investigated levels of TNF-alpha mRNA in the liver, vascular reactivity, liver NF-kappaB binding activity and levels of the inhibitory protein IkappaBalpha in the cytoplasm. RESULTS: Hemorrhagic shocked rats died in 27+/-6 min following the cessation of bleeding, experienced a marked hypotension (mean arterial blood pressure=20-30 mmHg) and had enhanced plasma levels of Tumor Necrosis Factor-alpha (208+/-22 pg ml(-1), 20 min after the end of bleeding). Furthermore, aortas taken 20 min after bleeding from hemorrhagic shocked rats showed a marked hypo-reactivity to phenylephrine (PE: 1 nM-10 microM) compared with aortas harvested from sham shocked rats. Hem shocked rats also had increased levels of TNF-alpha mRNA in the liver (15-20 min after the end of bleeding). Electrophoretic mobility shift assay showed that liver NF-kappaB binding activity increased in the nucleus 10 min after the end of hemorrhage and remained elevated until the death of animals. Western blot analysis suggested that the levels of inhibitory protein IkappaBalpha in the cytoplasm decreased at 5 min after the end of bleeding. Cyclosporin inhibited the loss of IkappaBalpha protein from the cytoplasm and prevented NF-kappaB binding activity in the nucleus. Furthermore, cyclosporin increased survival time (118+/-7 min; P<0.01) and survival rate (vehicle=0% and cyclosporin=80%, at 120 min after the end of bleeding), reverted the marked hypotension, decreased liver mRNA for TNF-alpha, reduced plasma TNF-alpha (28+/-7 pg ml(-1)), and restored to control values the hypo-reactivity to PE. CONCLUSIONS: Our results suggest that acute blood loss (50% of the estimated total blood volume over a period of 20 min) causes early activation of NF-kappaB which triggers an inflammatory cascade leading to a fatal outcome. Cyclosporin blocks NF-kappaB activation and protects against hypovolemic hemorrhagic shock.

Factors associated with hypotension and bradycardia after epidural blockade.

In order to identify patient-, anesthesia-, and surgery-related factors influencing the probability of hypotension and bradycardia after epidural blockade, an observational study was conducted on 1050 nonpregnant patients. Backward stepwise logistic regression was performed on the variables hypotension (systolic blood pressure < 90 mm Hg) and bradycardia (heart rate < or = 45 bpm). Hypotension and bradycardia occurred in 158 and 24 patients, respectively. The probability of hypotension increased when epidural fentanyl was administered (odds ratio [OR] = 2.18; 95% confidence interval [CI] = 1.16-4.11), with body weight and spread of epidural analgesia, and decreased when a tourniquet was used (OR = 0.01, CI = 0.01-0.02) and bupivacaine instead of carbonated lidocaine was administered (OR = 0.28, CI = 0.14-0.60). Sensitivity and specificity of the model were 89% and 88%, respectively. The probability of bradycardia was less in women (OR = 0.05, CI = 0.01-0.41) and when a tourniquet was used (OR = 0.04, CI = 0.02-0.09). Sensitivity and specificity were 50% and 97%, respectively. In conclusion, our analysis can contribute to identification of patients at high risk to develop hypotension and bradycardia after epidural blockade. If bupivacaine instead of carbonated lidocaine is used and epidural fentanyl is not administered a decrease in the incidence of hypotension may be anticipated.

A multifactorial analysis to explain inadequate surgical analgesia after extradural block.

A multivariate analysis of inadequate extradural analgesia was carried out prospectively on 1051 patients undergoing lumbar extradural anaesthesia for surgery performed on structures innervated by T10-S5. Ninety-six patients (9%) experienced pain during surgery. Age, extradural fentanyl, diazepam sedation and duration of surgery had no significant influence. We found some weak evidence that the type of surgery affects the risk of feeling pain. The probability of pain increased with increasing weight, except in overweight women, and was significantly greater for both shorter and taller patients, relative to patients of average height. The probability of pain decreased with increasing dose of local anaesthetic, increasing spread of extradural analgesia, addition of adrenaline, and fentanyl or thiopentone sedation. In conclusion, patient-, surgery- and anaesthesia-related factors influence the risk of inadequate extradural analgesia. If such factors are taken into account, an increase in the success rate may be anticipated.

Failure rate of epidural anaesthesia for foot and ankle surgery. A comparison with other surgical procedures.

To test whether epidural anaesthesia for foot and ankle surgery is associated with an unacceptably high incidence of inadequate surgical analgesia, we prospectively compared two groups of patients, one undergoing foot or ankle surgery (160 patients) and the other surgical procedures not performed in areas innervated by L5-S1 ( (168 patients). Lumbar epidural anaesthesia was performed in both groups by administering carbonated lignocaine 2% with adrenaline 1:200000. Seven patients in the foot-ankle group (4.4%) and 10 in the group for comparison (5.9%) exhibited inadequate surgical analgesia. This difference is not statistically significant. Within the foot-ankle group, a significantly lower dose of local anaesthetic per spinal segment had been given to patients who displayed inadequate analgesia, compared with those who exhibited satisfactory analgesia (P < 0.05).

A multifactorial analysis of the spread of epidural analgesia.

The controversies about the factors determining the spread of epidural analgesia are partly due to inappropriate methodology or sample size of previous studies. We performed a multivariate regression analysis on 803 ASA class 1-2 non-atherosclerotic adults, undergoing lumbar epidural anaesthesia according to a predefined standardised procedure. The spread of epidural analgesia is more accurately studied by analysing dose/segment (R2 = 0.671) instead of spread (R2 = 0.271) as dependent variable. The impact of local anaesthetic (2% lidocaine CO2 or 0.5% bupivacaine) and addition of adrenaline is not significant. Spread significantly increases with increasing age, weight, body-mass index, dose of local anaesthetic, addition of fentanyl, higher site of injection, and decreasing body height. The impact of age and dose is higher under the age of 40 and at doses lower than 20 ml. Increasing the total dose increases the dose needed to block one spinal segment. Unknown idiosyncratic factors still determine a certain proportion of the sample variance. The addition of adrenaline to lidocaine and the use of bupivacaine improve the predictability of spread. In conclusion, we found clinically significant correlations between a group of factors and epidural spread. Alternative anaesthetic solutions lead to different degrees of predictability.

[Comparison of carbonated lidocaine and mepivacaine in epidural anesthesia]. / Confronto tra lidocaina e mepivacaina carbonata nell'anestesia epidurale.

OBJECTIVE: To compare carbonated mepivacaine to carbonated lidocaine in epidural anaesthesia. DESIGN: Nonrandomised control trial. SETTING: University Hospital. PATIENTS: Forty patients undergoing epidural anaesthesia for orthopaedic surgery. METHODS: Epidural anaesthesia at the fourth lumbar interspace, administering either carbonated mepivacaine 20 ml (group M, 20 patients) or carbonated lidocaine 20 ml (group L, 20 patients). Parameters recorded: onset of sensory block (time required to reach L1 and time required to reach the upper level), cranial spread of analgesia (number of dermatomes), duration of block (time between achievement of maximum spread of analgesia and regression of sensory block by two dermatomes) and motor block (Bromage score). RESULTS: No statistically significant differences have been found between group M and group L in the time required to reach L1 (means and standard deviations 6.3 +/- 3.8 and 6.5 +/- 2.1 minutes, respectively), in the time required to reach the upper level of analgesia (means and standard deviations 14.3 +/- 4.2 and 16.5 +/- 3.5 minutes, respectively), in the cranial spread of analgesia (means and standard deviations 7.1 +/- 3.4 and 7.6 +/- 2.7 dermatomes, respectively) and in the degree of motor block (means and standard deviations 1.5 +/- 0.8 and 1.1 +/- 0.8, respectively). Group M exhibited a much higher duration of sensory block, compared to group L (means and standard deviations 91.6 +/- 20.2 and 58.8 +/- 23.4 minutes, respectively, p < 0.001). CONCLUSIONS: Carbonated mepivacaine is more indicated than carbonated lidocaine in epidural anaesthesia when a high duration of sensory block is desired.

[Postoperative pain in shoulder surgery]. / Il dolore postoperatorio nella chirurgia della spalla.

Postoperative shoulder pain should be adequately treated not only because of the high severity of the symptomatology often observed, but also because pain and muscle contraction render impossible an early rehabilitation programme. Regional anaesthesia, by virtue of its beneficial effects on the pathophysiology of pain and its influence on the rehabilitative problems of shoulder surgery, is the most adequate technique for the control of postoperative pain.

[Propofol and alfentanil in total intravenous anesthesia]. / Propofol e alfentanil in anestesia endovenosa totale.

We studied 22 patients undergoing total intravenous anaesthesia for both abdominal and superficial surgery. Anaesthesia has been induced and maintained with propofol (1 mg/kg in 20 seconds; 10 mg/kg/h for 10 minutes; 8 mg/kg/h for 10 minutes; 6 mg/kg/h until the end of the operation) and alfentanil (15 mg/kg before the induction and boli of 10-30 mg/kg in the presence of insufficient surgical analgesia). All the patients have been intubated after the administration of vecuronium 0.1 mg/kg, and artificially ventilated with air and oxygen (FiO2 0.4). We observed: 1) haemodynamic stability after the intubation and during surgery; 2) easy control of surgical analgesia; 3) early postoperative recovery, with no correlation with the doses of propofol and alfentanil; 4) absence of postoperative respiratory depression; 5) intraoperative amnesia; 6) low incidence of postoperative side effects. We conclude that, by virtue of the pharmacokinetic characteristics of propofol and alfentanil, most limitations of total intravenous anaesthesia have been overcome.

[Sedation with propofol in COPD patients in the ICU]. / La sedazione con propofol nei pazienti con COPD in ICU.

Sedation with propofol was achieved in 10 patients with COPD admitted into ICU because of acute respiratory insufficiency. Propofol dosage was 1-3 mg/kg-1/h and the testing period 30-144 h. Curarization was non required. Sedation with propofol, valued by means of Ramsay Score, was suitable in all tested patients. Bio-humoral and instrumental monitoring have not evidenced side effects.

[Pressure changes in the middle ear during nitrous oxide anesthesia]. / Modificazioni della pressione dell'orecchio medio durante anestesia con protossido d'azoto.

We studied middle ear pressure variations in 17 patients with mild upper airways or middle ear diseases, during nitrous oxide anaesthesia. We observed a significant increase in middle ear pressure during the administration of nitrous oxide, and a significant decrease after nitrous oxide was discontinued. Nine patients showed periodical reductions of the middle ear pressure during the inhalation of nitrous oxide, due to passive openings of the eustachian tube. In the remaining 8 patients (47%) this mechanism has not been effective. A comparison between these two groups shows significantly higher levels of middle ear pressure in the group of patients with abnormal function of the eustachian tube, both during and after the administration of nitrous oxide. Our results demonstrate that patients with mild upper airways or middle ear diseases are likely to show an impaired tubal function. Therefore, nitrous oxide should be used with caution in the presence of such diseases. Moreover, nitrous oxide is generally controindicated in middle ear surgery, as the pressure gradients between middle and external ear can jeopardize the success of the operation.

[Comparison of a combination of fentanyl and alfentanil with propofol in brief surgery]. / Confronto tra fentanyl e alfentanil in associazione al propofol nella chirurgia di breve durata.

We studied 96 patients undergoing short gynecological procedures. Anaesthesia has been induced with fentanyl 1.5 micrograms/kg (45 patients) or alfentanil micrograms /kg (51 patients) and a hypnotic dose of propofol, and maintained with 70% N2O via facial mask. We observed a better and more rapid control of surgical analgesia with alfentanil, and an earlier recovery of postoperative psychophysical functions. Post-induction apnea has been more frequent and prolonged in the alfentanil group, but no difference in the time necessary to recover an adequate ventilation has been observed between the two groups. Alfentanil anaesthesia determined a more marked intraoperative bradycardia. By virtue of the speed of onset and the short duration of action, alfentanil is a suitable anaesthetic agent for short surgical procedures, particularly in day-stay patients.

[New methods of electrophysiologic investigation in the diagnosis of brain death]. / Nuove metodiche di indagine elettrofisiologica nella diagnosi di morte cerebrale.

In the event of suspected brain death it is vital to arrive at a diagnosis as rapidly as possible and with the least chances of error. The paper examines the potentially and possible value of BAER recordings. Results are in line with those of other published studies which underline the value of this method, in spite of the fact it is limited by the possible presence of numerous factors which might invalidate recordings.

[Anesthesia for shoulder surgery. Comparison of anesthesiologic problems and technics]. / L'anestesia per la chirurgia della spalla. Problematiche e tecniche anestesiologiche a confronto.

We evaluated the ability of general, regional (interscalene block) and balanced anaesthesia (interscalene block supplemented by general anaesthesia) to manage the problems of shoulder surgery. Our results show that general anaesthesia is not adequate. Interscalene block provides intra and postoperative analgesia, allows an early realization of the postoperative rehabilitation programme and quickens the recovery of shoulder function. Therefore, interscalene block should routinely be performed. The positions of patient and surgeons cause the main disadvantages of anaesthesia with interscalene block alone, ad the control of airway of sedated patients is difficult and performing general anaesthesia in case of insufficient analgesia may be troublesome. Balanced anaesthesia, as compared to regional block alone, allows a safer control of respiration and an easier control of surgical analgesia.