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Biomedical subjects

T Prien

Publications and source records attributed to T Prien.

At least 37 records · Page 2Linked to original sources
PubMed1996

The effect of laryngeal mask cuff pressure on postoperative sore throat incidence.

STUDY OBJECTIVE: To study the effect of laryngeal mask airway (LMA) cuff pressure on the incidence of postoperative sore throat. DESIGN: Prospective, randomized, observational study. SETTING: Operating room of a university hospital. PATIENTS: 200 consecutive adult patients requiring anesthesia for gynecologic procedures. INTERVENTIONS: Anesthesia was induced with thiopental 3-5 mg/kg, fentanyl 2 micrograms/kg, vecuronium bromide 0.05mg/kg, and enflurane 0.8% to 2% and maintained with nitrous oxide and oxygen (65%/35%) and enflurane. MEASUREMENTS AND MAIN RESULTS: In Group 1, cuff pressure measurement was continuously performed until the end of the operation. In Group 2, 5 minutes after induction of anesthesia and 2 minutes after insertion of the LMA, cuff pressure was also continuously observed and reduced to the minimal pressure required for airtightness. In the recovery room, after the operation, patients were questioned for postoperative sore throat 4, 8, and 24 hours after the operation following a scoring protocol (score 0 = no complaints, score 1 = minimal sore throat, score 2 = moderate sore throat, score 3 = severe sore throat: "never a LMA again". Continuous monitoring of cuff pressure revealed a steady increase of pressure (during the first 60 minutes increases of 43 cm H2O) in Group 1. In Group 2, after release of air, cuff pressures were significantly lower through the entire operation when compared with Group 1. In Group 1, 8 patients claimed to have a sore throat (Score 1, n = 4; Score 2, n = 3; Score 3, n = 1). In Group 2, no patient complained of sore throat. CONCLUSIONS: A significant increase in cuff pressure is seen during the first 60 minutes. Three minutes after insertion of the laryngeal mask, cuff pressure can significantly be reduced without any major gas leakage. Postoperative sore throat can be reduced when cuff pressure is continuously monitored and kept on low-pressure values.

Adult↗
PubMed1996

Low-flow and minimal-flow anaesthesia using the laryngeal mask airway.

This study was designed to investigate whether the advantages of low- and minimal-flow anaesthesia can be combined with the laryngeal mask airway (LMA). Seventy female patients undergoing routine gynaecological surgery were investigated. After induction of anaesthesia and after positioning a laryngeal mask airway nos 3 and 4, patients were ventilated for 20 min with a fresh gas flow of 6 L min-1. Thereafter, the flow was reduced to 1 L min-1 in 50 patients and to 0.5 L min-1 in 20 patients. Once in the proper position, the LMA allowed flow reduction in all patients, indicating that no gas leakage occurred. It is concluded, that the application of low-flow and even minimal-flow anaesthesia is an alternative to high-flow anaesthesia. It can result in high annual savings and minimization of pollution. However, its use should be restricted to those anaesthesiologists who are experienced with the laryngeal mask airway and minimal-flow anaesthesia.

Adolescent↗
PubMed1996

Nitric oxide synthase inhibition restores vasopressor effects of norepinephrine in ovine hyperdynamic sepsis.

To investigate the hypothesis that nitric oxide synthase (NOS) inhibition restores the vasopressor response to norepinephrine (NE) in ovine hyperdynamic sepsis, eight sheep were chronically instrumented. In the non-septic portion of the study, NE was titrated to achieve an increase in mean arterial pressure (MAP) by 15 mm Hg ("small dose"). Small-dose NE was repeated 1 h after administration of the NOS inhibitor NG-nitro-L-arginine methyl ester (L-NAME; bolus 5 mg/kg, followed by 1 mg.kg-1.h-1). After 3 days of recovery, sepsis was induced by a continuous endotoxin infusion (Salmonella typhosa, 10 ng.kg-1.h-1). Three animals died during this period (data excluded). After 24 h, small-dose NE was given. If MAP increased less than 15 mm Hg, the NE dose was increased to achieve the targeted MAP change ("large dose"). Finally, both doses of NE were given after L-NAME administration. To increase MAP by 15 mm Hg in nonseptic animals, the rate of NE infusion was 0.18 +/- 0.03 microgram.kg-1.min-1 (small dose). During L-NAME infusion, this NE dose increased MAP by 32 +/- 8 mm Hg. In septic animals, small-dose NE increased MAP by only 9 +/- 2 mm Hg (P < 0.05 versus nonseptic state). To increase MAP by 15 mm Hg, the NE dose had to be increased to 0.34 +/- 0.06 microgram.kg-1.min-1 (large dose). During L-NAME infusion, NE administration increased MAP by 16 +/- 2 mm Hg and 28 +/- 4 mm Hg (small and large dose, respectively). Thus, L-NAME restored the vasopressor response to NE in sepsis, and increased the vasopressor response to NE in a similar fashion in healthy and septic sheep.

Animals↗
PubMed1996

Cardiac output is not affected during intraoperative testing of the automatic implantable cardioverter defibrillator.

INTRODUCTION: Perioperative mortality of patients undergoing implantation of automatic implantable cardioverter defibrillators (ICDs) has been reduced dramatically following the availability of transvenous-subcutaneous defibrillation leads. However, patients with severely reduced left ventricular function show a substantial rate of nonsudden cardiac mortality within the first year. Whether repeated intraoperative inductions of ventricular tachycardia/fibrillation (VT/VF) during implantation lead to hemodynamic deterioration and thus might contribute to development of end-stage heart failure in these patients is unknown. The purpose of the present study was to determine cardiac output and hemodynamic performance during transvenous-subcutaneous ICD implantation in patients with severe left ventricular dysfunction. METHODS AND RESULTS: In 11 patients with a left ventricular ejection fraction (EF) < or = 0.35, cardiac output was measured automatically with a combined continuous cardiac output/mixed venous oxygen saturation pulmonary artery catheter system. ICD implantation was performed during standardized general anesthesia. In the 11 patients (EF = 27 +/- 2% [mean +/- SEM]) a total of 95 episodes of VT/VF followed by defibrillation were induced (episodes per patient = 9 +/- 1; range 6 to 11). Cardiac index was 2.2 +/- 0.2 L.min-1.m-2 after induction of anesthesia (before start of surgery), and 1.9 +/- 0.1 L.min-1.m-2 immediately before first induction of VT/VF. After the last episode of VT/VF, cardiac index was 2.1 +/- 0.2 L.min-1.m-2. Cardiac index measured 1, 2, and 3 minutes after induction of VT/VF was not significantly different when compared to the preinduction value during any episode of VT/VF induction. Similarly, stroke volume index was 39 +/- 5 mL.m-2 immediately before first induction of VT/VF and 36 +/- 3 mL.m-2 after the last episode of VT/VF (NS). At the end of surgery, hemodynamic parameters did not exhibit any significant difference when compared to the data obtained before start of ICD implantation and testing. CONCLUSION: Extensive defibrillation tests during transvenous-subcutaneous ICD implantation in patients with severe left ventricular dysfunction are not associated with acute deterioration of cardiac performance.

Cardiac Output↗
PubMed1995

[Lithotomy position: respiratory resistance with thiopental and propofol anesthesia].

OBJECTIVE: To study airway resistance changes induced by placement in lithotomy position under thiopentone and propofol anaesthesia. DESIGN: Prospective, randomised study. SETTING: OR of a university hospital. PATIENTS: Consecutive sample of 36 patients without bronchopulmonary disease (ASA 1-2; 18-78 yr.; 45-100 kg) scheduled for elective surgery in lithotomy position under general (mask) anaesthesia; oral premedication with 0.3 mg.kg-1 dipotassium chloroazeptate on the evening before and in the morning of surgery. INTERVENTIONS: Injection of either 4-6 mg.kg-1 thiopentone or 2-2.5 mg.kg-1 propofol into a fast running peripheral infusion until loss of eyelash reflex. Placement of an oropharyngeal airway and assisted ventilation via anatomic mask until recovery of spontaneous respiration. Oscilloresistometric determination (Siregnost FD 5; Siemens AG, Erlangen) of airway impedance (ROS) before and after placement in lithotomy position. RESULTS: Before positioning ROS was 3.5 +/- 1.3 mbar.l-1.s-1 and 3.7 +/- 1.1 mbar.l-1.s-1 in the propofol and thiopentone group respectively. After positioning ROS was unchanged in the propofol group (3.8 +/- 1.8 mbar.l-1.s-1) and increased to 4.5 +/- 1.5 mbar.l-1.s-1 (p < 0.05) in the thiopentone group. CONCLUSION: Lithotomy positioning induces an increase in airway impedance under thiopentone but not under propofol anaesthesia.

Adolescent↗
PubMed1995

[Nausea and vomiting after gynecologic laparoscopies].

OBJECTIVE: To investigate the occurrence of postoperative nausea and vomiting (PONV) in relation to the menstrual cycle in patients anaesthetised with isoflurane and propofol. METHODS: 150 patients were randomly allocated to two groups (n = 75). All patients received antiemetic treatment with 20 micrograms/kg droperidol i.v. before induction of anaesthesia. In the isoflurane group, patients were anaesthetised with thiopental, fentanyl, vecuronium, and isoflurane; in the propofol group, with propofol, fentanyl, and vecuronium. Patients were ventilated with nitrous oxide/oxygen in both groups. RESULTS: Under isoflurane-based anaesthesia PONV occurred in 22 (29%) patients, under propofol-based anaesthesia in 4 (5%) patients (p < 0.05). 41 study participants underwent laparoscopy during the first 8 days of the menstrual cycle. 12 (29%) of these patients developed PONV (p < 0.05 vs second and third phase of the menstrual cycle). 10 of these 12 study participants were in the isoflurane group. Postoperative shivering occurred in 38 (51%) patients anaesthetised with isoflurane and in 12 (16%) patients of the propofol group (p < 0.05). CONCLUSIONS: The incidence of PONV is significantly higher when patients undergo laparoscopy during the first 8 days of the menstrual cycle. When compared to isoflurane, propofol results in a significantly lower incidence of PONV and postoperative shivering and a lower occurrence of postoperative pain.

Adult↗
PubMed1995

1 x ED90 dose of rocuronium bromide: tracheal intubation conditions and time-course of action.

The intubation conditions and time-course of action of a 0.3 mg kg-1 bolus of rocuronium were studied under alfentanil/propofol and fentanyl/thiopentone/enflurane anaesthesia. Forty healthy patients were randomly allocated to induction of anaesthesia with either alfentanil 20 micrograms kg-1 and propofol 2.0-2.5 mg kg-1, or fentanyl 3 micrograms kg-1 and thiopentone 4-6 mg kg-1. Approximately 5 min later, after calibration of mechanomyography, an i.v. bolus of 0.3 mg kg-1 rocuronium was administered. Laryngoscopy and tracheal intubation were attempted when maximum block occurred. Intubation was completed successfully in 39 patients. The passage of the tube was rated good or excellent in 18/20 (alfentanil/propofol group) and 18/19 patients in the other group. The times of onset were 65 s and 69 s, respectively. It is concluded that a 1 x ED90 dose of rocuronium will rapidly provide good or excellent intubation conditions in the majority of cases.

Adolescent↗
PubMed1994

Intradermal anaesthesia: comparison of several compounds.

OBJECTIVE: To compare the efficacy of different local anaesthetics to produce intradermal anaesthesia for venous cannulation and the discomfort associated with skin infiltration. DESIGN: Randomized, double blind study. SETTING: Induction room of a university hospital. PATIENTS: Convenience sample of 600 patients (18-65 years; ASA I-II) scheduled for elective surgery. INTERVENTIONS: Patients received one of six preparations: 0.9% saline, 1% prilocaine (Xylonest), 1% lidocaine (Xylocain), 1% mepivacaine-1 (Meaverin), 1% mepivacaine-2 (Scandicain), 1% procaine (Novocain). A skin wheal was raised on the dorsum of the hand by injecting 0.1 ml intradermally and 0.1 ml subcutaneously via a 27-g hypodermic needle. 60 seconds later an 18-g intravenous cannula was passed through that skin wheal into a vein. MEASUREMENTS: A visual analog scale (VAS) for pain (0 = no pain/10 = most pain imaginable) was used to assess pain elicited by raising the skin wheal and inserting the cannula. MAIN RESULTS: With regard to analgesic potency all five local anaesthetics were comparable (mean VAS-score 1.7-2.09) and effective when compared to 0.9% saline (mean VAS-score 4.2; P < 0.001). Infiltration pain was least with mepivacaine-1 (mean VAS-score 1.0; P < 0.001) and highest with procaine (mean VAS score 2.7; P < 0.001). CONCLUSIONS: Of the local anaesthetics tested, Mepivacaine-1 is the drug of choice for skin infiltration as its injection elicits least discomfort.

Adolescent↗
PubMed1993

[Hypertonic-hyperoncotic volume replacement (7.5% NaCl/10% hydroxyethyl starch 200.000/0.5) in patients with coronary artery stenoses].

OBJECTIVES: To determine the efficacy and safety of intravascular volume augmentation with a hypertonic saline-hyperoncotic HES solution prior to CABG. DESIGN: Randomized, double-blind, clinical trial. PATIENTS: Consecutive sample of 37 patients scheduled for elective CABG; mean age 64.5 (41-80; range) years and weight 74 (51-111) kg. INTERVENTIONS: Continuous, central-venous infusion of either 250 ml (approx. 3.5 ml/kg) HES (0.9% NaCl/10% hydroxyethyl starch 200.000/0.5) or HT-HES (7.5% NaCl/10% hydroxyethyl starch 200.000/0.5) in 15 minutes, following induction of anesthesia. MEASUREMENTS AND MAIN RESULTS: Groups were similar with respect to age, weight, and sex. 15 min. after fluid loading, cardiac index, pulmonary artery pressure, and wedge pressure had increased from baseline in both groups (p < 0.05), with a greater increase in the HT-HES-group (p < 0.05). In eight out of 18 patients, who had received HT-HES, transient drops in arterial blood pressure (mean 20% from baseline, range 10-35%) were observed during the first 5 minutes of infusion. Seven of the HT-HES-group patients developed transient left ventricular failure, predominantly 5-20 min. after infusion. No incidence of initial hypotension or LVF was observed in the HES-group. CONCLUSIONS: In patients with coronary artery disease, volume augmentation with hypertonic-hyperoncotic solutions may induce transient hypotension and post-infusion hypervolemic left heart failure.

Adult↗