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Biomedical subjects

O Ravlo

Publications and source records attributed to O Ravlo.

At least 19 recordsLinked to original sources
PubMed1993

Randomized evaluation of pulse oximetry in 20,802 patients: I. Design, demography, pulse oximetry failure rate, and overall complication rate.

BACKGROUND: Although pulse oximetry is currently in widespread use, there are few data documenting improvement in patient outcome as a result of the use of oximetry. The authors describe the study design, patient demographic findings, data validation, pulse oximetry failure rate, and overall postoperative complication rates in the first large prospective randomized multicenter clinical trial on perioperative pulse oximetry monitoring. METHODS: In five Danish hospitals, by random assignment, monitoring did or did not include pulse oximetry for patients 18 yr of age and older, whether scheduled for elective or emergency operations, or for regional or general anesthesia, except during cardiac and neurosurgical procedures. Operational definitions were established for perioperative events and postoperative complications. The data were collected preoperatively, during anesthesia, in the postanesthesia care unit, and until the day of discharge from the hospital or the seventh postoperative day. RESULTS: Of 20,802 patients, 10,312 were assigned to the oximetry group and 10,490, to the control group. In general, the demographic data, patient factors, and anesthetic agents used were distributed evenly. A slight intergroup difference was found in the distribution of age, duration of surgery, some types of surgery, and some types of anesthesia. The total failure rate of the oximetry was 2.5%, but it increased to 7.2% in patients with American Society of Anesthesiologists physical status 4 (P < 0.00001). In 14.9% of the patients, one or more events occurred in the operating room and 13.5% in the postanesthesia care unit. The overall postoperative complication rate was 9.7%. The total rates of cardiovascular and respiratory complications were 2.78% and 3.50%, respectively. Within the first seven postoperative days, 0.47% of the patients died. Anesthesia was not thought to have been solely responsible for any death, but in 7 patients (1 per 3,365), it was a possible contributory factor. CONCLUSIONS: Despite the finding of a few significant inter-group differences, the randomization was well balanced with a high validity of data. The overall postoperative complication rate was similar to that in other recent morbidity and mortality studies.

Adult↗
PubMed1993

Randomized evaluation of pulse oximetry in 20,802 patients: II. Perioperative events and postoperative complications.

BACKGROUND: The authors describe the effect of pulse oximetry monitoring on the frequency of unanticipated perioperative events, changes in patient care, and the rate of postoperative complications in a prospective randomized study. METHODS: The study included 20,802 surgical patients in Denmark randomly assigned to be monitored or not with pulse oximetry in the operating room (OR) and postanesthesia care unit (PACU). RESULTS: During anesthesia and in the PACU, significantly more patients in the oximetry group had at least one respiratory event than did the control patients. This was the result of a 19-fold increase in the incidence of diagnosed hypoxemia in the oximetry group than in the control group in both the OR and PACU (P < 0.00001). In the OR, cardiovascular events were observed in a similar number of patients in both groups, except myocardial ischemia (as defined by angina or ST-segment depression), which was detected in 12 patients in the oximetry group and in 26 patients in the control group (P < 0.03). Several changes in PACU care were observed in association with the use of pulse oximetry. These included higher flow rate of supplemental oxygen (P < 0.00001), increased use of supplemental oxygen at discharge (P < 0.00001), and increased use of naloxone (P < 0.02). The rate of changes in patient care as a consequence of the oximetry monitoring increased as the American Society of Anesthesiologists physical status worsened (P < 0.00001). One or more postoperative complications occurred in 10% of the patients in the oximetry group and in 9.4% in the control group (difference not significant). The two groups did not differ significantly in cardiovascular, respiratory, neurologic, or infectious complications. The duration of hospital stay was a median of 5 days in both groups (difference not significant). An equal number of inhospital deaths were registered in the two groups. Questionnaires, completed by the anesthesiologists at the five participating departments, revealed that 18% of the anesthesiologists had experienced a situation in which a pulse oximeter helped to avoid a serious event or complication and that 80% of the anesthesiologists felt more secure when they used a pulse oximeter. CONCLUSIONS: This study demonstrated that pulse oximetry can improve the anesthesiologist's ability to detect hypoxemia and related events in the OR and PACU and that the use of the oximeter was associated with a significant decrease in the rate of myocardial ischemia. Although monitoring with pulse oximetry prompted a number of changes in patient care, a reduction in the overall rate of postoperative complications was not observed.

Adult↗
PubMed1990

Priming principle with atracurium.

In order to substantiate the "priming principle" discussion, 44 patients admitted for elective gynecological surgery under modified neurolept anesthesia were randomized into two groups. In group I, atracurium was administered by a priming technique in which 0.1 mg/kg was given i.v. and, after 6 min, 0.5 mg/kg. In group II was given an atracurium bolus injection of 0.6 mg/kg. In group I onset time (median 61 sec, range 44-160 sec) was significantly more rapid than in group II (median 83 sec, range 60-128 sec). The median train-of-four ratio in group I was 0.80 (range 0.43-1.00, n = 23), 6 min after the priming dose, in 30% of these patients the TOF ratio was above 0.90 and in 22% below 0.70. It is impossible to determine a fixed pretreatment dose per kg body weight owing to the large individual variation in neuromuscular depression. Modification of the priming principle using incremental small doses of non-depolarizing neuromuscular blocking agents, with anesthetic induction, when the train-of-four ratio is between 0.90 and 0.70 or when there is clinical signs of neuromuscular block, might be an alternative in situations where rapid induction is required and where the use of suxamethonium is contraindicated.

Adult↗
PubMed1989

A randomized comparison between midazolam and thiopental for elective cesarean section anesthesia. I. Mothers.

In a randomized blind trial midazolam (0.3 mg kg-1) was compared with thiopental (4 mg kg-1), both combined with meperidine-nitrous oxide, for elective cesarean section anesthesia in 40 women. We found no statistically significant differences between thiopental and midazolam at induction, during operation or recovery with regard to maintenance doses, change in maternal neurologic status based on a modified Glasgow Coma Scale, systolic blood pressure, and heart rate. Induction time was 120 seconds with midazolam and 111 seconds with thiopental. There were significant differences with regard to diastolic blood pressure. Side effects occurred with approximately equal frequencies, but vomiting was significantly more frequent after thiopental. Perivenous tenderness and erythema occurred in four patients, all after thiopental. Midazolam appears to be a suitable alternative to thiopental for the induction and maintenance of anesthesia for elective cesarean section.

Adolescent↗
PubMed1989

A randomized comparison between midazolam and thiopental for elective cesarean section anesthesia: II. Neonates.

In a randomized blind trial, the general condition of 40 neonates was assessed following midazolam- or thiopental-based general anesthesia for elective cesarean section. Among 19 neonatal neurobehavioral observations and tests, statistically significant differences between the midazolam and the thiopental groups were rare. However, a statistically significant interaction with regard to body temperature, general body tone, and arm recoil was observed where results were inferior for midazolam, although only within the first 2 hours. It was concluded that midazolam is as safe as thiopental for the induction and maintenance of elective cesarean section anesthesia in neonates.

Anesthesia, Obstetrical↗
PubMed1989

A randomized comparison between midazolam and thiopental for elective cesarean section anesthesia: III. Placental transfer and elimination in neonates.

Forty neonates delivered by cesarean section were studied, half being delivered of mothers in whom anesthesia was induced with midazolam (0.3 mg/kg intravenously) and half of mothers given thiopental (4 mg/kg). At delivery, blood samples from mother and the umbilical vein were drawn for determination of plasma concentrations of thiopental, midazolam, and alpha-hydroxymidazolam. Over the next 60 hours, three blood samples were drawn using a randomized procedure of two blood samples at 30 different times. Placental transfer, expressed as the umbilical/maternal concentration ratio, was 0.96, 0.66, and 0.28, respectively, for thiopental, midazolam, and alpha-hydroxymidazolam. The transfer of thiopental was significantly more rapid than the transfer of midazolam and alpha-hydroxymidazolam. The population average of elimination half-life in neonates was 6.3 hours for midazolam and 14.7 hours for thiopental. Both values are substantially larger than those found in previous studies in adults.

Anesthesia, Obstetrical↗
PubMed1988

The influence of alfentanil on the intubating conditions after priming with vecuronium.

The ability of alfentanil 15 micrograms kg-1 or 30 micrograms kg-1 to improve intubating conditions was studied in four groups of 25 ASA class 1 patients. Induction of anaesthesia was with thiopentone 5 mg kg-1. Neuromuscular blockade was induced with vecuronium using the priming principle. The priming dose, priming interval and intubating dose were 0.01 mg kg-1, 4 min, and 0.1 mg kg-1, respectively. Intubation was attempted 1 min after the intubating dose. Intubating conditions were judged unacceptable in about 30% of the patients belonging to the control groups. Alfentanil 15 micrograms kg-1, when administered 65 s before intubation, reduced the incidence of coughing and diaphragmatic movement (P less than 0.05) but did not reduce the incidence of overall unacceptable intubating conditions. Alfentanil 30 micrograms kg-1, however, reduced the incidence of vocal cord movement (P less than 0.005) as well as coughing and diaphragmatic movement (P less than 0.002). Alfentanil 30 micrograms kg-1 reduced the incidence of unacceptable intubating conditions from about 30% to 4% (P less than 0.02).

Adult↗
PubMed1987

A comparison between two emergency cricothyroidotomy instruments.

As part of a training programme for younger doctors, two commercially available, emergency cricothyroidotomy sets were evaluated. Prior to the surgical procedure, half of the doctors in each group received an audiovisual lesson. In a simulated but realistic emergency situation, involving autopsy material, cricothyroidotomy was performed utilizing either the "Nutrake" or the "Gentofte" system. The audiovisual lesson increased the speed and the success rate of the doctors performing this procedure as well as strengthening their confidence. Both systems allowed positive pressure ventilation. The participating doctors achieved a higher success rate at a faster speed with the "Nutrake" set.

Catheterization↗
PubMed1987

Pain relief after major abdominal surgery: a double-blind controlled comparison of sublingual buprenorphine, intramuscular buprenorphine, and intramuscular meperidine.

In a double-blind randomized study of three groups of 18 patients scheduled for major abdominal surgery the efficacy and side effects of sublingual buprenorphine were tested and compared to intramuscular meperidine and buprenorphine. Single doses of either 75 mg of meperidine, 0.4 mg of sublingual buprenorphine, or 0.3 mg of intramuscular buprenorphine were used. Patients given buprenorphine as sublingual tablets were significantly more conscious in the immediate postoperative period (Glasgow Coma Scale) than when given buprenorphine or meperidine intramuscularly. Median pain intensity differences (PID) showed equal pain relief, whereas the summarized pain intensity differences (SPID) were significantly higher in the intramuscular buprenorphine group compared to the meperidine group. Three cases of respiratory acidosis in the meperidine group required IPPV treatment, and one case in the intramuscular buprenorphine group required treatment. Sedation and nausea were the most common side effects in all three groups. We conclude that sublingual buprenorphine is useful for relief of postoperative pain and exhibited administrative advantages, when the patients were able to cooperate.

Abdomen↗