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Biomedical subjects

J E Tetzlaff

Publications and source records attributed to J E Tetzlaff.

At least 37 records · Page 2Linked to original sources
PubMed1998

Heart rate variability and the prone position under general versus spinal anesthesia.

STUDY OBJECTIVE: To evaluate heart rate (HR) variability in the prone position with power spectral heart rate (PSHR) analysis during spinal and general anesthesia. DESIGN: Prospective, clinical evaluation of HR variability in the prone position. SETTING: Tertiary care teaching hospital. PATIENTS: 20 healthy, ASA physical status I and II patients scheduled for elective lumbar spine surgery in the prone position. INTERVENTIONS: Anesthetic technique was either a standard general anesthetic or spinal anesthetic, based on the preference of the patient. Power spectral heart rate, HR, and blood pressure (BP) readings were determined prior to anesthetic intervention and as soon as a stable PSHR reading was available in the prone position. MEASUREMENTS AND MAIN RESULTS: Heart rate and BP were recorded at baseline prior to anesthesia and at the time of stable PSHR data in the prone position. Power spectral heart rate data included low-frequency activity (LFa), high-frequency activity (HFa), and the ratio (LFa/HFa). Spinal anesthesia level was recorded by thoracic dermatome at complete onset. Data were collected from 20 patients; 12 patients chose spinal anesthesia and 8 chose general anesthesia. The prone position resulted in significant increase in HR in the spinal group and significant decrease in BP in the general anesthesia group. Low-frequency activity and LFa/HFa ratio were unchanged in the spinal anesthesia group and were significantly decreased in the general anesthesia group. Spinal level was T8.7. CONCLUSIONS: The association of less change in LFa activity and preservation of BP on assumption of the prone position in patients during low spinal anesthesia suggests better preservation of autonomic nervous system compensatory mechanisms during low spinal anesthesia than with general anesthesia.

Anesthesia, General↗
PubMed1998

Spinal anesthesia for elective lumbar spine surgery.

STUDY OBJECTIVE: To evaluate a large series of elective lumbar spine surgical procedures by a single surgeon whose patients were all offered spinal anesthesia. DESIGN: Retrospective chart review. SETTING: Tertiary-care teaching hospital. MEASUREMENTS AND MAIN RESULTS: The records of all elective lumbar spine procedures between 1984 and 1995 performed by one surgeon (GRB) were obtained, and 803 were identified. Of those 803 patients, 611 accepted spinal anesthesia. Data collected included patient demographics, details of the spinal and general anesthesia, perioperative complications, and impact of the spinal anesthetic options on the outcome of spinal anesthesia. General and spinal anesthesia patients were comparable for age, gender, height, and ASA physical status. Patients who received spinal anesthesia were significantly heavier than the general anesthesia patients. Among perioperative complications, nausea and deep venous thrombosis occurred significantly more often in the general than spinal anesthesia patients. Mild hypotension and decreased heart rate (HR) were the most common hemodynamic changes with spinal anesthesia, whereas hypertension and increased HR were the result of general anesthesia. Among spinal anesthetic drugs, plain bupivacaine was associated with the lowest incidence of supplemental local anesthetic use intraoperatively compared to hyperbaric bupivacaine or hyperbaric tetracaine. CONCLUSION: Spinal anesthesia is an effective alternative to general anesthesia for lumbar spine surgery and has a reduced rate of minor complications.

Anesthesia, General↗
PubMed1997

Effectiveness of bupivacaine administered via femoral nerve catheter for pain control after anterior cruciate ligament repair.

STUDY OBJECTIVE: To evaluate the quality of pain control achieved with continuous local anesthetic infusion via a femoral nerve catheter, and to determine the optimum concentration of bupivacaine necessary to maintain pain control after full surgical anesthesia is established with 0.5% bupivacaine. DESIGN: Randomized, prospective study. SETTING: Tertiary care teaching center. PATIENTS: 25 ASA physical status I and II patients scheduled to undergo arthroscopically-aided anterior cruciate ligament (ACL) reconstruction by one surgeon, and who were willing to accept a femoral nerve catheter for postoperative pain control. INTERVENTIONS: All patients received general anesthesia with propofol/alfentanil (10 ml/1 ml) mixture and nitrous oxide/oxygen (60%/40%) mixture via endotracheal tube. After induction of general anesthesia, a femoral nerve catheter was inserted with the aid of a nerve stimulator, and 20 ml of 0.5% bupivacaine was administered. The surgery was completed in a standard manner and the patients were randomized into three groups for the concentration of local anesthetic to continue the pain relief into the recovery phase. On awakening, all patients were determined to have a functioning femoral nerve catheter. Group 1 received 0.0625% (n = 8) bupivacaine, Group 2 0.125% (n = 9) bupivacaine, and Group 3 0.25% (n = 8) bupivacaine; all doses were initiated in a blinded manner at 0.12 ml/kg/hr. Patients also received intravenous patient-controlled analgesia with morphine via demand mode only, with a 1.0 mg dose and a 6 minute lock-out interval. MEASUREMENTS AND MAIN RESULTS: Pain was determined at defined intervals by visual analog scale (VAS). Data collected included demographics, VAS scores, and total morphine administered. All patients were pain-free on emergence from general anesthesia. No patient required parenteral opioid for pain control while in the postanesthesia care unit. There were no significant differences in pain scores among groups, and average pain scores (2.5 to 4.0) indicate good pain control throughout the entire hospitalization. There were no complications. CONCLUSIONS: Low concentrations of bupivacaine delivered via femoral nerve catheter after an established femoral nerve block can provide excellent postoperative pain control after ACL reconstruction.

Adult↗
PubMed1997

Tourniquet-induced hypertension correlates with autonomic nervous system changes detected by power spectral heart rate analysis.

STUDY OBJECTIVE: To determine the autonomic changes associated with pneumatic tourniquet-induced hypertension as measured by power spectral heart rate analysis (PSHR). DESIGN: Prospective study. SETTING: Tertiary teaching hospital. PATIENTS: 21 healthy-patients scheduled for lower extremity surgery, during which pneumatic tourniquet inflation was expected to exceed 90 minutes. INTERVENTIONS: Hemodynamic and PSHR data collected at 5 minute intervals during inflation of the pneumatic tourniquet. Tourniquet-induced hypertension (T-HTN) defined at 30% increase above baseline. MEASUREMENTS AND MAIN RESULTS: Blood pressure, heart rate, maximum changes in low frequency variability (LFa), high frequency variability (HFa), and their ratio (LFa/HFa) were measured. Of the 21 patients, 11 had T-HTN. A significantly greater increase in LFa and LFa/HFa ratio was seen in the T-HTN group, where patients were greater in age. LFa, HFa, and ratio were not significantly different with T-HTN until 60 minutes or greater. Best correlation with T-HTN occurred with maximum increase in LFa/HFa ratio compared with increase in LFa or decrease in HFa. CONCLUSION: Tourniquet hypertension correlated with activation of the sympathetic nervous systems, as measured by PSHR variables.

Adult↗
PubMed1993

Regional anaesthetic technique and the incidence of tourniquet pain.

The influence of regional anaesthetic technique on the incidence of lower extremity tourniquet pain was evaluated. We studied 60 patients undergoing orthopaedic procedures of the lower extremity with the use of a pneumatic tourniquet and anticipated inflation of 60 min or longer. Three different anaesthetic techniques were selected by random and draw; spinal anaesthesia (SAB) with plain 0.5% bupivacaine (15 mg) and 0.2 mg epinephrine added, lumbar epidural anaesthesia (EA) with 2% mepivacaine and 1:200,000 epinephrine added, and epidural anaesthesia (AEA) with the same solution alkalinized with bicarbonate. Onset and level of sensory blockade were determined by loss of painful sensation to pinprick. The incidence of tourniquet pain was determined at 15-min intervals or by patient complaint, by an observer unaware of group. Time to onset of pain, amount of treatment (i.v. fentanyl), and sensory level at the time of pain were determined. The SAB was compared with EA and AEA, and EA was compared with AEA. The SAB group was older. The sensory level achieved and duration of tourniquet inflation did not differ among groups. The incidence of tourniquet pain was lower with SAB than with EA and lower with AEA than with EA. There was no difference between SAB and AEA. This study demonstrated a lower incidence of tourniquet pain with spinal anaesthesia than with epidural anaesthesia to the same sensory level. However, this advantage is eliminated if the epidural anaesthetic was performed with an alkalinized local anaesthetic.

Anesthesia, Epidural↗
PubMed1993

pH adjustment of mepivacaine decreases the incidence of tourniquet pain during axillary brachial plexus anaesthesia.

The effect of pH adjustment of mepivacaine on the incidence of tourniquet pain during axillary brachial plexus anaesthesia was studied. Thirty-nine patients scheduled for hand surgery, during which use of pneumatic tourniquet for longer than 60 min was planned, were randomized into two groups. Both received axillary brachial plexus block with 40 ml, 1.4% mepivacaine, 1:200,000 epinephrine. The study group had 4 ml sodium bicarbonate (1 mEq.ml-1) added (final pH 7.31), and the control group had 4 ml saline added (final pH 5.6). The incidence of tourniquet pain was determined from cases for which tourniquet inflation lasted longer than 60 min. Tourniquet; pain was defined as poorly localized and distinct from an inadequate axillary block by a blinded observer. More tourniquet pain occurred in the control group. The authors conclude that alkalinization of mepivacaine for axillary brachial plexus anaesthesia may be indicated in cases where use of pneumatic tourniquet for long periods is planned.

Adult↗
PubMed1993

Potassium and anaesthesia.

Potassium is the principle intracellular ion, and its concentration and gradients greatly influence the electrical activity of excitable membranes. Because anaesthesia is so intimately involved with electrically active cells, potassium concentrations in surgical patients have received considerable attention in diagnostic and therapeutic applications. With the ongoing evolution in the indications for potassium, it is important to review the role of potassium in cellular activity, in storage and regulation, in diseases that alter potassium homeostasis, and in the therapeutic implications of perioperative alterations of potassium concentration. A rational approach to abnormal potassium values and the use of potassium in the operating room is sought, based on a physiological understanding of risks and benefits.

Anesthesia↗
PubMed1992

Upper airway oedema following autologous blood transfusion from a wound drainage system.

We report a case of a 70-yr-old white woman who underwent a revision of a total hip arthroplasty under general anaesthesia. The intraoperative course was stable without any complications and the estimated blood loss was 2500 ml. The patient received an autologous transfusion of blood from a wound drainage system in the recovery room. The transfusion was followed immediately by marked respiratory distress and upper airway oedema. She required emergency tracheal intubation and mechanical pulmonary ventilation. A coagulopathy also developed which was treated and resolved within 12 hr of the capillary leak phenomenon. The trachea was extubated on the first postoperative day and she had an uneventful course until discharge from the hospital two days later. We discuss the possible, aetiology of such a reaction to autologous blood including complement and platelet activation. It is suggested that reinfusion of nonwashed shed blood from a wound drainage system may present a hazard even though the fluid was autologous in origin.

Aged↗
PubMed1991

Intraoperative defect in haemostasis in a child receiving valproic acid.

This report describes the development of an intraoperative defect in haemostasis which occurred during surgery for lengthening of the heel cords and release of hip contractures in a patient receiving valproic acid. A review of the literature failed to find any other cases of a valproic acid-induced bleeding disorder occurring under anaesthesia and surgery. While recognized in the non-surgical literature, this case reports the first in which the development of a valproic acid-induced haemostatic defect occurred under anaesthesia. The subsequent course is discussed and some pathophysiological mechanisms are presented. It is suggested that for patients receiving valproic acid preoperative education should include PT/PTT, platelet and fibrinogen counts and bleeding time so that abnormal coagulation states can be recognized.

Child↗
PubMed1990

Fiber-type specific caffeine sensitivities in normal human skinned muscle fibers.

Caffeine sensitivity was studied in chemically skinned muscle fibers from vastus lateralis muscle obtained by biopsy during reconstructive knee surgery from 15 otherwise healthy young individuals. Muscle fiber type was determined by contracture occurring in strontium (slow-oxidative, type I fiber) or calcium (both type I and type II, fast glycolytic fiber) solutions and in several fibers after contracture testing by ATPase enzyme histochemistry. Caffeine sensitivity (mean +/- SD), defined as the threshold concentration inducing more than 10% of the maximal tension obtained with a calcium 3 x 10(-5) mM solution was 2.7 +/- 1.3 mM in 37 type I fibers, whereas it was 6.9 +/- 2.4 mM in 61 type II fibers. A paired t test showed a significantly increased sensitivity to caffeine in type I fibers (P less than 0.001) in 13 individuals in whom the two fiber types were identified. The mean (+/- SD) difference between type I and type II fibers was 4.1 +/- 1.9 mM. Type I fibers contracted with greater tension in response to the increasing concentration of caffeine than did type II fibers (P less than 0.05). These skinned fiber studies showed significantly different caffeine sensitivities between human type I and type II muscle fibers, as previously shown in animal muscles. The findings that human type I muscle fibers have higher caffeine sensitivity than type II muscle fibers should be helpful for the interpretation of the in vitro contracture test done in muscle strips containing type I and type II fibers in varying proportions.

Adenosine Triphosphatases↗
PubMed1986

Anaphylactoid reaction to atracurium.

Atracurium is a new intermediate-acting muscle relaxant, relatively devoid of cardiovascular effect in the clinical dose range. Histamine release is reported in a dose-dependent fashion, but below the threshold for haemodynamic effect within the recommended dose limits. We report a case of an anaphylactoid reaction to a low dose (0.2 mg X kg-1) of atracurium, and discuss the peculiar aspects of this case that predisposed the patient to this event.

Aged↗
PubMedDate not supplied

Total airway obstruction with neck extension: airway management of a patient with pharyngeal tumor.

Airway obstruction with the induction of anesthesia in children is common. Normally, neck extension with jaw thrust improves the airway. Flexion typically completes the obstruction. With the presence of a pharyngeal tumor, these relationships may not be the same. We present a case of complete airway obstruction with neck extension in the presence of a nasopharyngeal tumor. Flexion rather than extension of the neck relieved this airway obstruction. We highly recommend radiologic studies with neck extension and flexion in such cases.

Airway Obstruction↗
PubMedDate not supplied

Alkalinization of mepivacaine does not alter onset of caudal anesthesia.

STUDY OBJECTIVE: To determine the effect of alkalinization of mepivacaine on onset of caudal anesthesia. DESIGN: Randomized, blind study. SETTING: Colon-Rectal Surgery Service of the Tertiary Center at Cleveland Clinic Foundation. PATIENTS: Young, healthy adults undergoing anal surgery. INTERVENTIONS: Addition of bicarbonate (study group) or saline (control group) to mepivacaine. MEASUREMENTS AND MAIN RESULTS: At the onset of sacral anesthesia, demographics were measured. A slightly faster onset was found in the study group (4.28 vs. 6.08 minutes), but this was not statistically significant. CONCLUSIONS: Alkalinization of mepivacaine does not significantly accelerate the onset of caudal anesthesia.

Adult↗