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T Pedersen

Publications and source records attributed to T Pedersen.

At least 73 records · Page 4Linked to original sources
PubMed1994

The Bullard laryngoscope. Reports of two cases of difficult intubation.

The Bullard laryngoscope is a new combination of a fibreoptic light source and an anatomically shaped rigid blade, to aid visualization of the larynx. We present two patients with expected severe difficult endotracheal intubation and describe their anaesthetic management. Our experience confirms previous observations which showed that the Bullard laryngoscope provides an excellent view of the vocal cords in patients with severe difficult airways.

Epiglottis↗
PubMed1994

Platelet activation in major surgical stress: influence of combined epidural and general anaesthesia.

Platelets are activated in surgery releasing vasoactive substances such as serotonin and thromboxane. Platelets become temporarily hypoaggregable during surgery followed by a postoperative hyperaggregability. Local anaesthetics are known to inhibit platelet function but earlier reports are conflicting. In order to study the impact of the combined use of general and regional anaesthesia on platelet function during major surgery 16 otherwise healthy patients were randomised to either general anaesthesia (GA) (n = 8) or GA combined with epidural anaesthesia (GA+EPI) (n = 8) for elective upper abdominal surgery. Cyclic 3',5' adenosine monophosphate, plasma glucose, plasma cortisol and the rate pressure product (RPP) were markers of the stress response. ADP-induced platelet aggregation and the release products beta-thromboglobulin, serotonin and thromboxane 2 were measured in plasma before and during as well as for 3 days after surgery. A marked stress response was noted in both groups and epidural anaesthesia (EPI) only reduced the rate pressure product (RPP). Platelet aggregation was reduced during surgery, a little more so in the GA+EPI group. Postoperatively both groups showed significant hyperaggregability. The release products were not significantly influenced by regional anaesthesia. In conclusion epidural as combined with general anaesthesia affects platelet responses to major abdominal surgery only to a minor extent, although it may attenuate the haemodynamic response.

Adenosine Diphosphate↗
PubMed1994

Complications and death following anaesthesia. A prospective study with special reference to the influence of patient-, anaesthesia-, and surgery-related risk factors.

The present study describes risk factors, the incidence of complications and mortality in the anaesthetized patient. The aims were further to identify additional patient-, anaesthesia-, technique-, and surgery-related factors associated with cardiopulmonary complications and mortality, to describe the value of preoperative radionuclide cardiography in patients with cardiopulmonary insufficiency, and to evaluate the importance of perioperative manual evaluation of the response to train-of-four nerve stimulation for the occurrence of residual neuromuscular blockade in the recovery room. Complications attributable to anaesthesia-complications caused mainly by the anaesthetic procedure-occurred in 0.6% (1:170) of the patients, and mortality attributable to anaesthesia was found to be 0.04% (1:2500). An analysis of the patient data suggests that the seriously ill patients (ASA-class > or = 3) were more likely to be affected by errors and a substantial negative outcome such as acute myocardial infarction, irreversible cerebral damage or death, than were more healthy patients (ASA 1-2). One-third of the complications attributable to anaesthesia are judged preventable. Cardiopulmonary complications associated with anaesthesia and surgery and requiring intervention occurred in 1:11 of the anesthetized patients. The cardiopulmonary complications were associated with elderly patients (> or = 70 yr), patients with preoperative clinical signs of ischaemic heart disease and recent myocardial infarction, chronic heart failure, and chronic obstructive lung disease, as well as perioperative and emergency procedures involving major abdominal surgery. In patients with severe cardiovascular or pulmonary insufficiency (high-risk patients) preoperative radionuclide cardiography could distinguish between different levels of cardiopulmonary risk in the anaesthetized patient. Patients with a preoperative left ventricular ejection fraction < 50% or > 70% demonstrated a high incidence of cardiopulmonary complications following anaesthesia (70%). It is recommended that left ventricular ejection fraction be measured in patients referred for major surgery who have an increased risk of cardiopulmonary complications as evidenced clinically by heart failure or severe ischaemic heart disease. Hypotension before anaesthetic induction is associated with a high incidence of cardiopulmonary morbidity and mortality. Postoperative pulmonary complications in comparable groups of patients depend primarily on the type of surgery, as major abdominal surgery was related to the highest incidence of pulmonary complications. Regional anaesthesia may be a superior technique to general anaesthesia, especially in elderly patients with chronic obstructive lung disease admitted to major orthopaedic surgery. Furthermore, in avoidance of postoperative complications such as residual neuromuscular blockade, the choice of muscle relaxant was more decisive than was manual evaluation of the response to train-to-four nerve stimulation.(ABSTRACT TRUNCATED AT 400 WORDS)

Aged↗
PubMed1993

Sequential intrapulmonary and systemic activation of coagulation and fibrinolysis during and after total hip replacement surgery.

Hip joint replacement surgery, using acrylic cement for prosthesis fixation, is associated with intraoperative cardiorespiratory dysfunction, and a high frequency of postoperative proximal deep vein thrombosis (DVT). Levels of prothrombin fragments 1+2 (F1+2), tissue plasminogen activator antigen (t-PA), plasminogen activator inhibitor 1 activity (PAI-1), D-dimer and interleukin 6 (IL-6) were measured in arterial (AB) and mixed venous blood (MVB) in five patients during and after total hip replacement operation with acrylic cement prosthesis fixation. Sequential peaks of F1+2, t-PA, PAI-1 and IL-6 appeared, starting with activation of coagulation during preparation of bone, closely followed by activation of fibrinolysis. Later, this was counteracted by an antifibrinolytic response and increase of IL-6. After a fibrinolytic shutdown on the third postoperative day as evidenced by a drop in t-PA and D-dimer concentrations, a second wave of coagulation was seen at the end of the first week. The present model, with frequent sampling of blood entering and leaving the lungs, confirms our earlier findings of the lung as a key organ in promoting coagulation following traumatic activation.

Aged↗
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↗
PubMed1993

Effectiveness of single dose prophylaxis with cefotaxime and metronidazole compared with three doses of cefotaxime alone in elective colorectal surgery.

OBJECTIVE: To compare three doses of cefotaxime alone with a single dose of cefotaxime and metronidazole for the prophylaxis of infection after elective colorectal operations. DESIGN: Prospective random control trial. SETTING: Hillerød and Frederiksberg Hospitals, Copenhagen, Denmark. SUBJECTS: 660 consecutive patients who were to undergo elective colorectal operations during a 48 month period (January 1987-January 1991); 93 (14%) were withdrawn after randomisation leaving 567 for assessment. INTERVENTIONS: Mechanical bowel preparation, and then either cefotaxime (Claforan) 2 g intravenously at induction of anaestesia and 3 and 9 hours later (n = 280) or a single dose of cefotaxime 2 g plus metronidazole (Flagyl) 1.5 g intravenously at induction of anaestesia (n = 287). RESULTS: 44 patients in the cefotaxime group developed wound infection (16%) compared with 19 (7%) in the combined group (p < 0.001). In the cefotaxime group 22 of the 241 patients who had an anastomosis developed leaks (9%) compared with 8 of the 239 in the cefotaxime/metronidazole group (3%). There were no differences in the incidence of intra-abdominal abscesses or burst abdomens. The most common organisms isolated from wounds were Escherichia coli and Bacteriodes fragilis. CONCLUSION: One dose of cefotaxime and metronidazole is active against a wide range of organisms and resulted in significantly fewer wound infections than three doses of cefotaxime alone.

Adult↗
PubMed1993

Complement activation during extracorporeal circulation. In vitro comparison of Duraflo II heparin-coated and uncoated oxygenator circuits.

The degree of complement activation during cardiopulmonary bypass is considered a valuable parameter of biocompatibility of the extracorporeal circuit. In an in vitro setting with a heart-lung machine primed with fresh whole blood and saline solution, the C3 activation products C3b, iC3b, and C3c and the terminal complement complex were measured in double-antibody enzyme immunosorbent assays. No differences were found between seven sets treated with Duraflo II heparin coating and seven uncoated sets after 2 hours of circulation. C3 activation products (expressed as median and 95% confidence intervals) increased from 4.5 AU (2.8 to 12.3 AU) to 16.5 AU (10.0 to 19.4 AU) in the uncoated sets (p = 0.02) and from 4.6 AU (2.2 to 5.8 AU) to 19.3 AU (3.5 to 27.1 AU) in the coated sets (p = 0.02). Terminal complement complex increased from 5.7 AU (2.7 to 11.3 AU) to 13.6 AU (8.2 to 17.8 AU) in the uncoated sets (p = 0.02) and from 7.9 AU (4.6 to 11.4 AU) to 17.3 AU (9.4 to 35.1 AU) in the coated sets (p = 0.02). A significant drop in thrombocyte levels was observed in both coated and uncoated sets. In a supplementary series, the sterilization process did not influence the results. Although Duraflo II heparin coating is considered highly effective in preventing coagulation, it did not prevent complement activation in the present in vitro study. We hypothesize that the mode by which the heparin molecule is bound to the surface may be essential to obtain effects on both coagulation and complement system.

Biocompatible Materials↗
PubMed1992

Anaesthetic practice and postoperative pulmonary complications.

The aim of this study was to identify risk factors associated with postoperative pulmonary complications. The influence of the anaesthetic technique was evaluated (i.e. general contra regional anaesthesia and long contra intermediately acting muscle relaxants (pancuronium and atracurium)) taking into account the patient's age, the presence or absence of chronic obstructive lung disease (preoperative risk factors), the type of surgery and the duration of anaesthesia (perioperative risk factors). Seven thousand and twenty-nine patients undergoing abdominal, urological, gynaecological or orthopaedic surgery were included in the study. A total of 290 patients (4.1%) suffered from one or more postoperative pulmonary complications. Six thousand and sixty-two patients received general anaesthesia and 4.5% of these had postoperative pulmonary complications. Of the patients admitted to major surgery receiving pancuronium, 12.7% (135/1062) developed postoperative pulmonary complications, compared to only 5.1% (23/449) receiving atracurium (P < 0.05). When stratified for type of surgery and duration of anaesthesia, conventional statistics showed no difference between pancuronium and atracurium as regard postoperative pulmonary complications. However, a logistic regression analysis indicated that long-lasting procedures involving pancuronium entailed a higher risk of postoperative pulmonary complications than did other procedures. In patients having regional anaesthesia, only 1.9% (18/967) developed postoperative pulmonary complications (P < 0.05 compared to general anaesthesia). However, when stratified for type of surgery there was a significantly higher incidence of postoperative pulmonary complications only in patients undergoing major orthopaedic surgery under general anaesthesia, 11.5% compared to 3.6% in patients given a regional anaesthesia.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1990

[Prostatotomy. Long-term results].

Sixty-five patients were treated with transurethral incision of the prostate (TUI-P) on account of slight obstructive enlargement of the prostate. Out of these, 46 were followed-up with a median period of observation of just under four years. In five patients prostatotomy proved insufficient and resection or repeated TUI-P was necessary. 80% of the patients considered that micturition had improved as assessed subjectively by means of a simple rank scale. Assessed symptomatically according to Madsen & Iversen's scale, a median score of 2 and less than 10 was found in 85%. Assessed objectively by means of urine flow measurement, a median peak flow of 10.5 ml/second was found and greater than 9 ml/second in 73%. No structures were demonstrated and none of the patients were incontinent. The magnitude of the ejaculate was unchanged in 26%, less in 39% while this was unknown in 35%. These results do not differ essentially from corresponding long term observations and the method must be considered particularly suitable for treatment of obstructive moderate hypertrophy of the prostate.

Aged↗
PubMed1990

[Retrograde ileography. Contrast imaging of the terminal ileum by colonoscopy].

The distal ileum, the segment most frequently affected by small intestinal disease, may be difficult to visualize by conventional x-ray techniques. In recent years various methods have been described for retrograde ileography during or after colonoscopy. However, these methods require special equipment and may be difficult to perform in practice. We have therefore tried out a somewhat modified technique. Patients with suspected distal ileal disease are examined on a fluoroscopy table at the x-ray department. When necessary, biopsies are taken during the introduction of the scope. With the tip of the colonoscope in the terminal ileum (or coecum) a catheter is introduced through the biopsy channel into the distal ileum. Water-soluble contrast (Mixobar) is then instilled under fluoroscopic control and films are taken in the supine, oblique and prone positions. Owing to gas already present in the ileum a double contrast effect is obtained. The ileography is completed in 5-10 minutes and entails no additional discomfort for the patient. The technique is easy to learn and requires no special equipment. It does not obviate the need for conventional small bowel enema, but may be a valuable supplement to this examination when distal ileal pathology is suspected.

Colonoscopes↗
PubMed1990

Does perioperative tactile evaluation of the train-of-four response influence the frequency of postoperative residual neuromuscular blockade?

The authors conducted a randomized controlled clinical trial to evaluate the usefulness of perioperative manual evaluation of the response to train-of-four (TOF) nerve stimulation. A total of 80 patients were divided into four groups of 20 each. For two groups (one given vecuronium and one pancuronium), the anesthetists assessed the degree of neuromuscular blockade during operation and during recovery from neuromuscular blockade by manual evaluation of the response to TOF nerve stimulation. In the other two groups, one of which received vecuronium and the other pancuronium, the anesthetists evaluated the degree of neuromuscular blockade solely by clinical criteria. The use of a nerve stimulator was found to have no effect on the dose of relaxant given during anesthesia, on the need for supplementary doses of anticholinesterase in the recovery room, on the time from end of surgery to end of anesthesia, or on the incidence of postoperative residual neuromuscular blockade evaluated clinically. The median (and range of) TOF ratios recorded in the recovery room were 0.75 (0.33-0.96) and 0.79 (0.10-0.97) in the vecuronium groups monitored with and without a nerve stimulator, respectively. These ratios were significantly higher than those found in the pancuronium groups, which wre 0.66 (0.06-0.90) and 0.63 (0.29-0.95), respectively. However, no difference was found between the vecuronium and pancuronium groups in the number of patients showing clinical signs of residual neuromuscular blockade, as evaluated by the 5-s head-lift test.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1990

A prospective study of risk factors and cardiopulmonary complications associated with anaesthesia and surgery: risk indicators of cardiopulmonary morbidity.

The aims of this study were: 1) to describe the frequency and type of cardiopulmonary complications, 2) to identify factors significantly associated with cardiovascular and pulmonary complications associated with anaesthesia and surgery, and 3) to estimate the total risk of cardiopulmonary complications for an anaesthetic when a combination of risk factors is present. Seven thousand three hundred and six anaesthetized patients undergoing gastrointestinal, urological, gynaecological, and orthopaedic surgery were included in the study; 6.3% (1:16) had one or more cardiovascular complications requiring intervention associated with anaesthesia and surgery, and 4.8% (1:21) had pulmonary complications. The total incidence of patients with one or more complications associated with anaesthesia and surgery was 9.4% (1:11). Based on logistic regression analyses, our data indicate that the following patient categories constitute high risk patients with regard to cardiovascular complications: patients aged greater than or equal to 70 years, patients with a history of ischaemic heart disease (IHD) with previous myocardial infarction less than 1 year, a history of chronic heart failure (CHF), and in patients admitted to major surgery. The extent of pulmonary complications following anaesthesia and surgery was significantly correlated to patients aged greater than or equal to 70 years, preoperative chronic obstructive lung disease (COLD), major surgery, and to general anaesthesia involving muscle relaxants. Attempts to estimate the cardiopulmonary complications which may accompany anaesthesia and surgery provided important information about the anaesthetic course and outcome. With our model it seems possible to distinguish between very different levels of cardiopulmonary risk in the anaesthetic patient.

Aged↗
PubMed1990

A prospective study of mortality associated with anaesthesia and surgery: risk indicators of mortality in hospital.

The aims of this study were to: 1) determine the incidences and causes of mortality associated with anaesthesia and surgery, 2) identify important factors associated with mortality in hospital, and 3) estimate the mortality risk associated with anaesthesia and surgery when a combination of risk factors are present. A total of 7306 anaesthetized patients undergoing abdominal, urological, gynaecological, or orthopaedic surgery were included in the study. Of these, 0.05% (1:1800) died during anaesthesia, 0.1% (1:730) during the recovery period, and the overall mortality rate in hospital was 1.2% (1:81). Most deaths occurred in the elderly (greater than or equal to 70 years of age) and were unavoidable due to progression of the presenting condition, such as advanced cancer, or co-existing diseases such as cardiopulmonary or renal failure. Of the patients who developed myocardial infarction (MI) following anaesthesia, 67% (8/12) died in the postoperative period. Half of the MI patients who died received regional anaesthesia, and in addition suffered from periods of cardiovascular dysfunction intraoperatively. By utilizing logistic regression analysis, a model for prediction of mortality risk was developed. The model included five significant preoperative predictive variables: age; patients with history of chronic heart disease, and renal disease; emergency surgery; and the type of operation. With this model it is possible to distinguish between patients with very different mortality risks.

Adult↗
PubMed1990

Cardiopulmonary complications in high-risk surgical patients: the value of preoperative radionuclide cardiography.

In a prospective study we examined the strength of association between preoperative left ventricular performance measured by radionuclide cardiography in patients with cardiac or pulmonary insufficiency (high-risk patients) and cardiopulmonary complications associated with anaesthesia and surgery. Detailed pre-, intra- and postoperative data collected for 7306 anaesthetized patients were included in the study. One hundred and thirty-one patients (1.8%) were classified as high-risk patients, and 95 patients were examined with radionuclide cardiography. The results demonstrated a 58% incidence of cardiovascular complications for high-risk patients when the left ventricular ejection fraction (LVEF) was abnormal (less than 50% or greater than 70%) compared with 12% when LVEF was normal (50-70%). In addition, high-risk patients with left ventricular end-diastolic volume (LVEDV) greater than 140 ml developed cardiovascular complications in 37% of the cases. Patients admitted to major surgery with LVEF less than 50 or greater than 70% were at greater risk than patients with LVEF = 50-70% as demonstrated by a significant increase in the total incidence of cardiopulmonary complications, 70% vs. 17%. It is appropriate to measure LVEF in patients admitted for major surgery who have an increased risk of cardiopulmonary complications as clinically evidenced by heart failure or severe ischaemic heart disease. As the predictive information given by LVEDV was less than that given by LVEF, there are no clinical reasons for measurement of LVEDV.

Adult↗
PubMed1990

Deep vein thrombosis of lower extremities. Diagnosis by real time ultrasonography.

In 150 patients with possible deep venous thrombosis in the lower extremities, the diagnostic accuracy of real time ultrasonography (US) with 3.5, 5.0 or 7.5 MHz transducers was assessed using venography as standard. In the area of the common femoral/popliteal vein, US was correct in 147 patients, giving an accuracy of 98 percent. There were no false negative studies, giving a sensitivity of 100 percent (60/60) and three false positive studies, giving a specificity of 97 percent (87/90). The results were almost the same using all the three frequencies. The simplicity and accuracy of US make it a useful diagnostic tool.

Adolescent↗
PubMed1989

[Ultrasonography in deep venous thrombosis].

In 54 patients with suspected deep vein thrombosis in the lower extremity, B-scan ultrasonography was compared with contrast venography for diagnostic accuracy. In the area of the common femoral/popliteal vein ultrasonography was correct in 53 patients, giving an accuracy of 98% (53/54). There were no false-negative studies, which gives a sensitivity of 100% (21/21). There was one false-positive study for a specificity of 97% (32/33). The technique is inexpensive and produces no discomfort to the patient. It is quite obvious that even small hospitals have the equipment and the competent staff to carry out this examination. We claim that B-scan ultrasonography is a certain, non-invasive method of demonstrating deep vein thrombosis in the common femoral/popliteal vein area.

Femoral Vein↗