Biological changes after liver transplantation according to the presence or not of graft steatosis.

AIM: To assess the consequences of graft steatosis on postoperative liver function as compared with normal liver grafts. PATIENTS AND METHODS: From January 2005 to December 2007, liver transplant patients were prospectively included, excluding those who experienced arterial or biliary complications or presented acute rejection. All patients had a surgical biopsy after reperfusion. Patients were compared according to the rate of macrovacuolar steatosis: namely above or below 20%. RESULTS: Fifty-three patients were included: 10 in the steatosis group and 43 in the control group. No significant difference was observed in terms of morbidity, mortality, and primary non- or poor function. Nevertheless, biological changes after the procedure were significantly different during the first postoperative week. Prothrombin time, serum bilirubin, and transaminases were significantly increased among the steatosis group compared with the control group (P < .05). CONCLUSION: This case-controlled study including a small number of patients, described postoperative biological changes among liver transplantations with steatosis in the graft.

Aging reduces the reliability of epidural epinephrine test doses.

BACKGROUND AND OBJECTIVES: The authors recently determined that intravascular injection of an epinephrine test dose reliably produced an increase in heart rate > or = 20 beats/min in young individuals. However, aging is associated with a significant reduction in beta-adrenergic responsiveness. This study was designed to determine whether aging decreases the magnitude of heart rate (HR) increase after intravascular injection of epinephrine. METHODS: Heart rate and systolic blood pressure were recorded during randomized and double-blind injections of 3 mL lidocaine plain or lidocaine with 10 or 15 micrograms epinephrine in 30 elective surgical patients between 21 and 81 years old. RESULTS: Increasing age was associated with smaller increases in HR after intravascular injection of epinephrine. The reduction in HR increase was statistically significant after 10 micrograms (P = .006, r2 = .24), but not after 15 micrograms (P = .25, r2 = .05) of epinephrine. Heart rate increases were of greater magnitude for patients younger than 40 years old (P = .01 for 10 micrograms epinephrine, and P = .03 for 15 micrograms epinephrine). One patient (of 11) over 60 did not respond to the 15 micrograms test dose with tachycardia. Aging did not alter systolic blood pressure increases after 10 or 15 micrograms epinephrine (P = .27, r2 = .04 and P = .4, r2 = .03, respectively). CONCLUSIONS: Aging is associated with a reduction in the magnitude of HR increase after intravenous injection of epinephrine. The results suggest that to detect an intravascular injection in healthy people, a test dose containing 10 micrograms epinephrine will suffice before the age of 40. However, even 15 micrograms epinephrine will not be totally reliable in older patients, owing to decreased beta-adrenergic responsiveness.

Epidural and intravenous fentanyl produce equivalent effects during major surgery.

BACKGROUND: The benefit of epidural versus intravenous fentanyl administration for postoperative analgesia is controversial. In the current study, the intraoperative effects of epidural versus intravenous fentanyl administration were compared during major surgery. METHODS: Twenty elective patients scheduled for thoracoabdominal esophagectomy under general anesthesia with propofol infusion were randomly allocated to receive either intravenous or epidural boluses of 50-100 micrograms fentanyl in a double-blind fashion to maintain hemodynamic stability. Plasma cortisol and fentanyl, as well as total urinary catecholamines, were obtained at the end of the operations. RESULTS: Hemodynamic variations were similar except that patients receiving epidural fentanyl had a lower incidence of heart rate reduction (> 20% reduction from baseline, P < 0.05). There were no differences in mean intraoperative fentanyl (1,115 +/- 430 and 1,010 +/- 377 micrograms, epidural and intravenous, respectively) or propofol (2,281 +/- 645 and 2,452 +/- 1,169 mg) doses, number of boluses of fentanyl (nine in both groups), plasma fentanyl concentration (1.13 +/- 0.4 and 1.02 +/- 0.46 ng/ml), or number of anesthesiologists correctly identifying the site of fentanyl administration. Similarly, there were no differences in plasma glucose (8.9 +/- 1.8 and 9.3 +/- 1.8 mM) and cortisol (696 +/- 446 and 846 +/- 257 mM), or urinary epinephrine (12 +/- 3.7 and 13.1 +/- 9.2, micrograms/sample) and norepinephrine (42.7 +/- 26.7 and 39.1 +/- 27.6, micrograms/sample). CONCLUSIONS: There appears to be no clinical advantage to epidural administration of fentanyl over intravenous administration during anesthesia for major surgery.

Double-blind comparison between inverse sequence induction with atracurium and rapid sequence induction with succinylcholine.

In this double-blind randomized study of 60 patients, a new rapid sequence induction technique (RSI), the so-called inverse sequence induction technique (ISI), is compared to the standard RSI using succinylcholine (SUX). All patients were premedicated with midazolam 0.07 mg.kg-1 and morphine 5 mg im. The patients in the ISI group received atracurium 0.6 mg.kg-1 followed after 1 min by thiopental 5 mg.kg-1. The patients in the SUX group were precurarized with atracurium 0.06 mg.kg-1 followed after 3 min by thiopental 5 mg.kg-1 and succinylcholine 1.5 mg.kg-1. In both groups patients were intubated 1 min after thiopental injection by a trained blinded anesthetist who graded intubation conditions from 1 (excellent) to 4 (impossible). Intubation scores (ISI: 1 and SUX: 1 (range 1-3)) and intubation times (from laryngoscopy to cuff inflation: ISI 18 +/- 10 s, SUX 19 +/- 8 s) as well as mean arterial pressure, heart rate, SpO2 and EtCO2 values were not significantly different between groups. Three patients in the ISI group failed to maintain a handgrip. In both groups all patients were able to cough forcefully at the time of thiopental injection. These data emphasize the reliability and safety of ISI as an alternative for RSI when succinylcholine is contraindicated. However, the unpleasantness of awake partial curarization may limit its acceptance.

Prolonged intrathecal fentanyl analgesia via 32-gauge catheters after thoracotomy.

We hypothesized that intrathecal fentanyl infusion would provide excellent analgesia, require lower doses than necessary for the epidural or intravenous route of administration, and reduce the incidence and/or severity of side effects. Accordingly, we studied 12 patients during 48 h after thoracotomy (three pneumonectomies, six lobectomies, and three multiple resections of metastases or pleural surgery). The mean dose of fentanyl infused intrathecally was 0.81 +/- 0.26 microgram.kg-1 x h-1, and plasma fentanyl concentrations ranged between 0.49 +/- 0.19 and 0.72 +/- 0.34 ng/ml. Four patients needed a supplementary bolus of intrathecal fentanyl. Pain scores decreased below 30/100 within 1 h when measured at rest but required 24 h to decrease to the same level during coughing. Pulmonary function tests returned to approximately 50% of preoperative values within 1 h of fentanyl infusion. Mean respiratory rates averaged 19 +/- 4, and no episode of apnea was detected. Pruritus, nausea, and headache occurred, respectively, in four, one, and zero patients. Excessive pressure in the infusion system occurred frequently, limiting fentanyl infusion in two patients. All catheters were removed intact; however, one broke outside of the patient's back. This study demonstrates that intrathecal fentanyl infusion can safely provide rapid and intense analgesia but that current 32-gauge intrathecal catheters are not well suited for prolonged postoperative use.

A randomized comparison of intravenous versus lumbar and thoracic epidural fentanyl for analgesia after thoracotomy.

Administration of large doses of fentanyl is a popular method to provide postoperative analgesia after thoracotomy. It is however unclear whether epidural lumbar (L) or epidural thoracic (T) administration of fentanyl confers any major advantage over intravenous (iv) infusion. Using a randomized prospective study design, we compared the potential benefits of L, T, and iv fentanyl administration after thoracotomy in 50 patients. Epidural catheters were not injected during surgery. Postoperatively a fentanyl infusion (5 micrograms/ml) was started at 1 microgram.kg-1.h-1 after a bolus of 1 microgram/kg and adjusted to maintain a score < or = 30/100 at rest using a visual analog scale (VAS) for pain. Data were prospectively collected before surgery, at fixed intervals during the 48 h of fentanyl infusions, and the day of discharge. There was no difference between the groups in overall quality of analgesia at rest and after coughing, quantity of fentanyl delivered (L = 1.15 +/- 0.38, T = 1.22 +/- 0.23, iv = 1.27 +/- 0.3 micrograms.kg-1.h-1), incidence of pruritus needing treatment (L = 2, T = 1, iv = 0 patients), need to decrease fentanyl infusion rate because of side effects (L = 2, T = 2, iv = 4 patients), importance of pulmonary infiltrates, or arterial blood gas values. One patient (L group) needed naloxone (0.04 mg iv). Intravenous patients were more frequently nauseated (P = .009) and needed boluses of fentanyl more often (L = 3 +/- 9, iv = 6 +/- 12, T = 4 +/- 8; P = .04).(ABSTRACT TRUNCATED AT 250 WORDS)

Effect of local anesthetic concentration on capillary blood flow in human skin.

OBJECTIVES: The objective of this study was to evaluate and compare the effect of lidocaine, mepivacaine, and bupivacaine on capillary blood flow in humans over therapeutic and subtherapeutic concentrations. METHODS: The effect of each treatment in eight unmedicated male volunteers was measured in a randomized, controlled, double-blind comparison. Each participant received subcutaneous injections (total, 14), at separate sites on the abdomen, consisting of 0.2 ml lidocaine (0.05%, 0.5%, 1%, and 2%), mepivacaine (0.05%, 0.5%, 1%, and 2%), bupivacaine (0.025%, 0.25%, 0.5%, and 0.75%), saline, or saline with epinephrine (5 micrograms/ml), and at an additional site a needle stick was performed and no injection made. Cutaneous blood flow was measured with a laser Doppler capillary perfusion monitor before and for 60 minutes after these interventions. RESULTS: The maximum increase in cutaneous blood flow was 277 +/- 141% to 511 +/- 136% (mean +/- SE) after lidocaine, 124 +/- 110% to 316 +/- 155% after mepivacaine, and 242 +/- 193% to 725 +/- 198% after bupivacaine. The increase in blood flow depended on local anesthetic concentration: low concentrations induced minimal changes, whereas higher concentrations caused great increases in cutaneous blood flow. Injection of saline or needle stick alone increased cutaneous blood flow 285 +/- 237% and 260 +/- 121%, respectively. CONCLUSIONS: Our findings indicate that the trauma of needle stick or saline injection produces a significant increase in cutaneous capillary blood flow. Injection of clinically useful concentrations of bupivacaine and lidocaine produced even greater increases in capillary blood flow, indicating a vasodilatory effect. Injection of the lowest concentrations of lidocaine and bupivacaine caused flow to increase to a magnitude similar to that after injection of saline. In contrast, clinically useful concentrations of mepivacaine do not increase capillary blood flow to a greater extent than saline, and lower concentrations tend to blunt the increase in blood flow, indicating a mild vasoconstrictor effect.

A prospective evaluation of the failure rate of spinal anaesthesia for transurethral prostatic resection.

The rate of failed spinal anaesthesia, defined as the need for unplanned general anaesthesia, was evaluated in a prospective study involving 137 patients undergoing transurethral resection of the prostate (TURP). The incidence of sensations at the operative site which did not require general anaesthesia was also evaluated. Attention to details was emphasized in the technique. Patients randomly received either hyperbaric Niphanoid tetracaine (n = 74; 6 or 10 mg) or hyperbaric bupivacaine (n = 61; 6 mg), with or without adrenaline. General anaesthesia was necessary in one patient (0.72%). Twelve additional patients reported sensations at the operative site which were rapidly relieved by light intravenous supplementation with low doses of fentanyl and/or thiopentone. The patients reporting sensations did not differ in demographic characteristics, spinal technique, local anaesthetic, or degree of sensory or motor blockade. Addition of adrenaline to the 6-mg doses of both tetracaine and bupivacaine decreased the incidence of sensations at the operative site.

Comparison between ropivacaine and bupivacaine after subcutaneous injection in pigs: cutaneous blood flow and surgical bleeding.

In this randomized, blinded study, we sought to determine whether the vasoconstriction produced by ropivacaine after subcutaneous injection is sufficient to decrease surgical bleeding. Anesthesia was induced in seven piglets (weight, 12.2-20.4 kg) with intraperitoneal thiopental and maintained with intravenous methohexital. Five sites were injected with 10 ml of one of the following solutions: 0.25% ropivacaine, 0.25% bupivacaine, either solution plus 5 micrograms/ml epinephrine, or saline. Another site was left uninjected for control. Capillary blood flow was measured at each site with a laser Doppler before and ten minutes after the injections. An incision 5 cm in length was then made through the dermis, and blood loss was measured over ten minutes. We found no significant differences in capillary blood flow and blood loss between bupivacaine and ropivacaine. Addition of epinephrine decreased capillary blood flow (p less than 0.05) and tended to decrease blood loss. Capillary blood flow correlated with blood loss (r2 = 0.106; p less than 0.05). We conclude that, in contrast to previous studies, ropivacaine did not decrease capillary blood flow in our model. Similarly, ropivacaine did not reduce bleeding from surgical incisions. The reason for these surprising results is not clear but is unlikely to be the larger volume of solutions injected because no such effect was observed with saline alone.

Laryngospasm-induced pulmonary edema.

We report the case of a 6-month-old child who developed acute pulmonary edema because of laryngeal spasm during orthopedic manipulations for congenital hip dysplasia. Laryngospasm was probably secondary to an unsuspected light level of anesthesia, maintained via face mask. No other predisposing factors, such as enlarged adenoid tonsils, laryngitis, epiglottitis, mechanical stimulation of the larynx or aspiration of foreign material were identified. Serious oxygen desaturation and bradycardia ensued, during inefficient attempts at positive pressure ventilation. After emergency intubation without muscle relaxant, copious pink secretions emerged from the airway. Negative pressure pulmonary edema was confirmed by chest X-ray, and short-lasting arterial desaturation despite positive pressure ventilation with high oxygen concentration. This type of pulmonary edema is caused by marked elevated negative intra-airway pressure, massive sympathetic discharge causing a blood shift from the systemic to the pulmonary circulation, and accentuation of physiological ventricular interdependence during forceful inspiratory effort against a closed glottis. As usual in such cases, pulmonary edema and laryngospasm resolved spontaneously without specific treatment, and extubation was carried out uneventfully two hours later. The child suffered no sequelae.

Test doses: optimal epinephrine content with and without acute beta-adrenergic blockade.

The authors studied the optimal epinephrine content of an epidural test dose, and determined criteria to identify intravascular injections in subjects with or without beta-adrenergic blockade. Nine healthy nonpregnant subjects 25-36 years of age were given intravenous infusions of saline or esmolol in random order. During each infusion, they received a series of five injections (3 ml each) of either saline, 1% lidocaine or 1% lidocaine containing 5, 10, or 15 micrograms of epinephrine. Thirty minutes after completing these two infusions, propranolol was administered as a bolus injection, and the series of five injections repeated. All injections were double blind and randomized. During saline infusion, all injections containing epinephrine significantly increased heart rate (HR) by an average of 31-38 beats/min when compared with that following plain lidocaine (P less than 0.05), and increased systolic blood pressure by an average of 17-26 mmHg (P less than 0.05 for the 15-micrograms dose only). During esmolol infusion, epinephrine injections increased HR by an average of 23-31 beats/min (P less than 0.05), and increased systolic blood pressure by an average of 18-30 mmHg (P less than 0.05 for 10 and 15 micrograms). After propranolol injection, epinephrine injections caused a decrease in HR by an average of 21-28 beats/min (P less than 0.05), whereas systolic blood pressure increased by an average of 22-35 mmHg (P less than 0.05 for 10 and 15 micrograms only). Without beta-adrenergic blockade, an increase in HR greater than or equal to 20 beats/min was 100% sensitive and specific for intravascular injection of 10 or 15 micrograms of epinephrine.(ABSTRACT TRUNCATED AT 250 WORDS)

Effect of propofol on cerebrospinal fluid pressure and cerebral perfusion pressure in patients undergoing craniotomy.

The effects of propofol on cerebrospinal fluid pressure, mean arterial pressure, cerebral perfusion pressure and heart rate were studied during induction, tracheal intubation and skin incision in 23 patients scheduled for elective craniotomy. Premedication consisted of midazolam 0.1 mg/kg intramuscularly and metoprolol 1 mg/kg orally. Measurements were made or derived at time zero and 0.5, 1, 1.5, 2 and 3 minutes after an induction dose of propofol 1.5 mg/kg. A continuous infusion of propofol was started at time zero at a rate of 100 mg/kg/minute. Fentanyl 2 micrograms/kg was added before tracheal intubation, application of the pin head holder and skin incision. Cerebrospinal fluid pressure and mean arterial pressure decreased significantly 2 minutes after propofol alone, by 32% and 10% respectively, while a cerebral perfusion pressure above 70 mmHg was maintained. Heart rate did not change. Propofol combined with moderate dose of fentanyl, obtunded the usual cerebrospinal fluid and arterial pressure responses to intubation and other noxious stimuli. Thus propofol seems to be a suitable intravenous anaesthetic agent for induction and maintenance in neuroanaesthesia.

Myocardial injury after electrical burns: short and long term study.

Miscellaneous cardiac abnormalities can occur after electrical burns. The long term outcomes are still unknown. We studied 10 patients, 9 of whom suffered high-voltage electrocution, and one of whom was struck by lightning. Serial electrocardiograms (ECG) and serum MB creatine phosphokinase isoenzyme (MB-CPK) activities were obtained during their stay in hospital. ECG and thallium 201 cardiac scintigraphy at rest, as well as echocardiograms were obtained in all patients 4 to 48 months after discharge. In hospital, 9 patients showed one or more abnormal findings at physical examination (4 cases), ECG (8 cases), MB-CPK (1 case). At long term follow-up, 5 patients had one or more myocardial functions or conduction abnormalities, with or without symptoms. One patient had compensated heart failure. Nine patients were asymptomatic. Abnormal ECG findings persisted in 3 patients. Three cardiac scans showed evidence of regional myocardial hypoperfusion. Decreases in left ventricular indices measured by echocardiogram were found in 3 patients. We conclude that high-voltage electrocution is associated with a high incidence of cardiac abnormalities, which may persist. Long term evaluation, requiring cardiac T1 201 scintigraphy and echocardiogram, may be justified.