Efficacy and safety of dipyrone versus tramadol in the management of pain after hysterectomy: a randomized, double-blind, multicenter study

BACKGROUND AND OBJECTIVES

We assessed the efficacy and safety of dipyrone in comparison with tramadol in the relief of early postoperative pain following abdominal hysterectomy.

METHODS

A total of 151 women between 18 and 60 years of age undergoing abdominal hysterectomy during general anesthesia participated in a randomized, double-blind, controlled, multicenter study. Seventy-three patients received dipyrone and 78 received tramadol. Patients received an intravenous loading dose of the study drug immediately after operation followed by intravenous (IV) maintenance infusion and IV on-demand boluses up to a maximum number of predetermined doses/day of 8 g dipyrone and 500 mg tramadol. The duration of the study was 24 hours.

RESULTS

The mean (SD) number of boluses in the dipyrone group was 3.8 (2.4) and 3.5 (2.5) in the tramadol group (95% confidence interval, -0.455 to 1.175), and the percentage of patients requiring rescue IV morphine (dipyrone 26.9%, tramadol 26.8%) was not statistically significant. Other analgesic efficacy parameters, such as pain intensity differences, sum of pain intensity differences, pain relief assessed by the patient, or patients who required the maximum number of demand doses, were not different between treatment groups. A significantly higher percentage of adverse gastrointestinal effects was found in patients given tramadol (42.1%) than in patients given dipyrone (20.2%) (P <.05). Also, a significantly higher number of tramadol-treated patients required ondansetron to control nausea and vomiting at 1 hour (19% v 7%), 2 hours (26% v 11%), and 24 hours (46% v 29%) (P <.05) after surgery. Patients and the investigators reported similar tolerability for both study arms.

CONCLUSIONS

Dipyrone and tramadol showed similar efficacy for early pain relief after abdominal hysterectomy. Nausea and vomiting, possibly caused by the tramadol, occurred more frequently in those patients. In this group, the need of the antiemetic drug ondansetron was also higher.

A comparison of two constant-dose continuous infusions of remifentanil for severe postoperative pain

We evaluated the analgesic efficacy and safety of two continuous constant-dose infusions of IV remifentanil, without infusion rate increments or the addition of boluses, in patients with severe postoperative pain during the first 4 h after general anesthesia with IV propofol-remifentanil. Thirty patients were randomly assigned to two groups of 15 subjects each according to the remifentanil dose administered: 0.1 microg. kg(-1). min(-1) IV (Group A) or 0.05 microg. kg(-1). min(-1) IV (Group B). Rescue analgesia was provided with meperidine (0.5 mg/kg IV) when pain intensity on the simple verbal scale (SVS) > or =2. The criteria for adequate analgesia (SVS 0-1, respiratory frequency >8/min. and SpO(2) >90%) after 4 h were met by 78% and 75% of the patients in Groups A and B, respectively (P = ns). "Meperidine rescue" analgesia was significantly more in Group B (26%) than in Group A (6%) (P < 0.05). There were no cases of respiratory depression, and nausea and emesis occurred in one patient in each group (6.5%). We conclude that IV remifentanil is an effective and safe opioid for the treatment of postoperative pain at a constant dose of 0.1 microg. kg(-1). min(-1) with a need for rescue analgesia 4 times less than a constant dose of 0.05 microg. kg(-1). min(-1).

IMPLICATIONS

Our study suggests that the use of a constant continuous infusion of remifentanil 0.1 microg.kg(-1).min(-1)IV is an effective alternative in the treatment of severe postoperative pain.

[Comparative study of inhalation induction by vital capacity breath in adults using 6% sevoflurane with oxygen or 4.5%sevoflurane in 50% nitrous oxide]

OBJECTIVE

To evaluate the efficacy, side effects and hemodynamic characteristics of induction by vital capacity breath in adults using 6% sevoflurane and oxygen versus 4.5% sevoflurane and 50% nitrous oxide.

PATIENTS AND METHODS

We assigned 50 ASA I-II patients aged 20 to 70 years old randomly to two groups of 25 to receive either 6% sevoflurane in oxygen or 4.5% sevoflurane in nitrous oxide. All patients were premedicated with oral bromazepam (1.5 to 3 mg). Induction was by vital capacity breath using a Mapleson A circuit (8 l. min-1) for 5 min. We recorded induction time, side effects, hemodynamic variables and patient opinion after surgery.

RESULTS

Induction time was significantly faster for the sevoflurane-oxygen group (60 +/- 10 s) than for the sevoflurane-nitrous oxide group (71 +/- 8 s) (p < 0.001). Complications were minor and hemodynamic variables stable in both groups, with no statistically significant differences. The patients expressed satisfaction with both induction techniques.

CONCLUSIONS

A vital capacity breath of 6% sevoflurane provided rapid induction. Induction was no more rapid when 50% nitrous oxide was added and the incidence of side effects did not decrease. Hemodynamic variables are stable during induction with sevoflurane with or without nitrous oxide, making this a well-tolerated alternative technique that is positively evaluated by patients.

Analysis of herpes simplex virus 1 and 2 infection in women with high risk sexual behaviour in Mexico

BACKGROUND

This paper describes the seroprevalence and risk factors of Herpes simplex virus (HSV) infection in a group of female prostitutes from Mexico City.

METHODS

Women who consented to participate in the study voluntarily attended a sexually transmitted disease (STD) clinic during 1992. A standardized questionnaire was administered and a blood sample was obtained from each participant. Type-specific Western blot serology was performed to determine the serostatus of HSV-1 and HSV-2 for participants. Bivariate and multivariate analyses were applied to identify variables associated with an increased risk for HSV infection.

RESULTS

Prevalences of infection among the 997 prostitutes studied were 93.9% for HSV-1 and 60.8% for HSV-2. Only 1.8% of the women were seronegative for both viruses. The only variable associated with HSV-1 seropositivity was crowding index. The following variables were associated with an increased risk for infection with HSV-2: age, level of education, working site, born outside Mexico City and increasing time as a prostitute.

CONCLUSIONS

This is the first assessment of HSV infection in Mexico and may be useful for the development and application of control and preventive measures among the prostitute population at risk of acquiring and transmitting human immunodeficiency virus (HIV) and other STD.

[Remifentanyl. Indications in anesthesia]

Remifentanil is a new opioid in the fentanyl family. Developed and marketed by Glaxo Wellcome Inc., it was approved by the U.S. Food and Drug Administration in July 1996 and has been available for use in Spain since the end of 1997. Remifentanil is an analog of fentanyl (4-piperidyl anilide) with a methyl-ester group that allows the molecule to be hydrolyzed by esterases in plasma and tissues. Rapid onset and metabolism make it an easy drug to control for achieving the desired depth of anesthesia, although these aspects are also the drug's main drawbacks given that the anesthesiologist must plan and initiate postoperative analgesia before surgery ends. Rapid onset and potency also mean that the use of this drug for either postoperative analgesia or monitored sedation in awake state with spontaneous breathing needs further study to assess safety.

Low prevalence of hepatitis B markers among Mexican female sex workers

OBJECTIVES

To estimate the prevalence and associated risk factors of hepatitis B virus (HBV) serological markers in female sex workers (FSW) in Mexico City.

METHODS

The study population consisted of 1498 FSW who attended a detection centre for human immunodeficiency virus (HIV) in Mexico City, between January and October 1992. Study participants responded to a standardised questionnaire and provided a blood sample for serology of syphilis, HIV, and HBV.

RESULTS

A total of 0.2% (95% CI 0.1-0.3) of the population were hepatitis B surface antigen (HBsAg) carriers. The general prevalence of antibodies to hepatitis B core antigen (anti-HBc) was 6.3% (95% CI 5.5-7.1). This marker of previous exposition to HBV, was independently associated by logistic regression multivariate analysis with age, working in the street, and history of blood transfusion (BT) before 1987 (OR 4.8, 95% CI 2.1-11.3). Syphilis prevalence was 7.6% (95% CI 6.2-8.9) and HIV prevalence was 0.1% (95% CI 0-0.3).

CONCLUSIONS

The prevalence of HBV infection in this group of Mexican FSW is lower than previously reported in other countries. In addition, the frequency of HBsAg carriers is similar to that in the general Mexican population. The absence of two major risk factors for HBV transmission in this group of FSW--that is, injecting drug use and anal intercourse, could help to explain this finding. However, the positive association between anti-HBc and history of blood transfusion demonstrated here, highlights the need to reinforce strict control of blood supplies in Mexico.

[Comparative study of sevoflurane and nitrous oxide versus halothane and nitrous oxide in pediatric anesthesia: efficacy and hemodynamic characteristics during induction]

OBJECTIVES

To study the efficacy, side effects and hemodynamics of anesthetic induction in pediatric patients using sevoflurane and nitrous oxide or halothane and nitrous oxide.

PATIENTS AND METHODS

We studied 80 pediatric ASA I-II patients aged between 1 and 10 years old scheduled for infraumbilical surgery of short duration. The patients were randomly assigned to two groups of 40 to receive one of the two drug combinations. All the children were premedicated with nasal midazolam 0.2 mg.kg-1. Induction was by inhalation of increasing concentrations of sevoflurane or halothane. The maximum inspired concentration during induction was 7% for sevoflurane and 3% for halothane. We analyzed induction time, side effects and hemodynamic variables.

RESULTS

The induction time was 2.06 +/- 0.5 min for halothane and 1.6 +/- 0.6 min for sevoflurane (p < 0.01). We observed no differences between the groups in coughing, laryngospasm, bronchospasm, secretions, apnea, nausea, vomiting, agitation or hiccoughing. Supraventricular beats appeared in 22.5% of patients in the halothane group and in 5% of the sevoflurane group. Induction with both anesthetics caused significant decreases from baseline blood pressure levels but no significant changes in heart rate.

CONCLUSIONS

Inhaled sevoflurane in 60% nitrous oxide provides rapid but gentle anesthetic induction, with hemodynamic stability and a low incidence of airway complications. Sevoflurane is therefore a reasonable alternative to halothane for pediatric surgery.

Specific immunoglobulins to soybean hull allergens in soybean asthma

Soybean asthma, which occurred as an epidemic among patients in Barcelona, Spain, is associated with specific IgE to soybean hull allergens. The purpose of this study was to investigate the possible role of specific IgG, IgG subclasses, IgA, and IgM in the pathogenesis of soybean asthma. We studied 3 groups of subjects from Barcelona: group 1, 12 asthmatic epidemic patients; group 2, 23 asthmatic nonepidemic patients; and group 3, 32 nonallergic subjects. Specific IgE was determined by radioimmunoassay and specific IgG, IgG subclasses (1, 2, 3, and 4), IgA, and IgM by amplified enzyme-linked immunosorbent assay. Cross-inhibition studies were performed for specific IgE and IgG4. We partially characterized the soybean hull allergens that bind specific IgE, IgG, and IgG4 by sodium dodecyl sulfate-polyacrylamide gel electrophoresis/Western blot. Percentage of positive results for the assays of the 8 Igs are as follows: for group 1, 100% (IgE), 75% (IgG), 16.6% (IgG1), 8.3% (IgG2), 0% (IgG3), 66.6% (IgG4), 25% (IgA), and 25% (IgM); for group 2, 4.3% were positive for specific IgE only; and for group 3, 0% (IgE), 0% (IgG), 6.2% (IgG1), 9.4% (IgG2), 9.4% (IgG3), 9.4% (IgG4), 6.2% (IgA), and 6.2% (IgM). The correlation between the specific IgE and the other specific Igs was significant between IgE and IgG4 in group 1 only (r = 0.752, p < 0.01). Cross-inhibition studies demonstrated a higher inhibitory capacity for IgG4 than for IgE. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis/ Western blot demonstrates three low molecular weight protein bands that bind specific IgE, IgG, and IgG4. This study suggests that specific IgG4 to soybean hull allergens plays a role in the pathogenesis of soybean asthma and corroborates the role of specific IgE in the same disease.

Epidemiology of human T-lymphotropic virus type II (HTLV-II) infection in Spain. HTLV Spanish Study Group

The human T-lymphotropic virus type II (HTLV-II) has recently been associated with the genesis of some subacute neurological syndromes and, rarely, with atypical T-lymphoid malignancies. The virus is endemic in some Amerindian and African tribes, and among intravenous drug users (IDUs) in North America and Europe. Given that HTLV-II is transmitted by the same routes as other human retroviruses, the screening of antibodies to HTLV-II in blood donors has became a matter of controversy in some countries. Herein, we describe the clinical, epidemiological and virological features of 113 individuals with HTLV-II infection identified in Spain up to September 1995. Most of them (94/113; 83%) were male, and all but seven were natives. Four were African immigrants living in Madrid and 3 had been born in other European countries. All but six subjects were IDUs, and sexual transmission of HTLV-II and transfusion were involved in five and one individual, respectively. Eighty-four percent of the IDUs infected with HTLV-II were co-infected by HIV-I (93/107). Clinical manifestations potentially linked to HTLV-II were absent, although an IDU male co-infected by HIV-1 and HTLV-II developed a severe non-inflammatory proximal myopathy. In conclusion, HTLV-II infection is present in Spain, mainly among IDUs, with a growing incidence and a current overall prevalence of 2.0 percent.

[Comparative study of recovery from general anesthesia with halothane or sevoflurane in pediatrics]

OBJECTIVES

To assess the clinical signs of awakening and recovery from anesthesia with sevoflurane and 60% nitrous oxide in comparison with halothane and nitrous oxide administered to children.

PATIENTS AND METHOD

A prospective study in 39 pediatric ASA I-II patients under 10 years of age scheduled for infraumbilical or otolaryngological surgery. The patients were randomly assigned to 2 groups to receive sevoflurane (n = 20) or halothane (n = 19). All the children received nasal doses of 0.2 mg/kg-1 midazolam before surgery. Induction was achieved by inhalation of a mixture of 40% oxygen and 60% nitrous oxide by face mask along with increasing concentrations of sevoflurane or halothane. Maintenance was with halogenated anesthetic at 1 MAC and 60% nitrous oxide-oxygen along with nerve blockade in the infraumbilical procedures or intravenous analgesia in the otolaryngological operations. We recorded time until awakening, orientation, score on the Aldrete scale and adverse effects during the recovery period.

RESULTS

The children who received sevoflurane awoke and were well oriented earlier than were those in the halothane group (10.7 +/- 5.8 versus 18.7 +/- 9.8 min until awakening and 15.4 +/- 8.6 versus 22.1 +/- 10 min for orientation); likewise the sevoflurane group children received higher scores on Aldrete's scale earlier than did those in the halothane group. There were no statistical differences between the 2 groups with respect to side effects during the period of awakening and recovery.

CONCLUSIONS

Awakening and recovery are significantly faster with sevoflurane than with halothane, while the incidence of side effects are similar with the 2 agents.

[HTLV-I infection in Spain. Analysis of 24 cases identified until November, 1994. Spanish Group for the Study of HTLV-I/II)]

BACKGROUND

HTLV-I is a human retrovirus which has been implicated in the genesis of tropical spastic paraparesia (TSP), adult T-cell leukemia (ATL) and some patients with uveitis, subacute arthropathies and lymphocytary alveolitis. The virus is endemic in some zones of the Caribbean countries, Japan, subsaharian Africa, Middle East and Melanesia. Given that HTLV-I is transmitted by similar routes as HIV, anti-HTLV-I antibody screening is carried out in blood donors in some countries.

METHODS

The clinical, epidemiologic and virologic characteristics of the patients with HTLV-I infection identified in Spain up to November 1994 are described.

RESULTS

Twenty-four Spanish residents have been identified with HTLV-I infection including 16 Spaniards and 8 immigrants from endemic areas. Thirteen (53%) are males and 11 (47%) females. Most of the persons born in Spain (12/16; 75%) have lived in endemic areas or have maintained sexual relations with natives of them. Four patients were diagnosed with TSP, three with ATL and another with lymphomatoid granulomatosis and angiocentric T-cell lymphoma. The remaining patients were asymptomatic at the time of diagnosis. Two HTLV-I carriers were identified on blood donation.

CONCLUSIONS

HTLV-I infection is present in Spain being found in Spanish natives and, to a lesser degree, in immigrants from endemic areas. It is therefore recommendable to analyze the cost-benefit of anti-HTLV-I screening in blood donors.