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Biomedical subjects

G Kuhlman

Publications and source records attributed to G Kuhlman.

14 recordsLinked to original sources

The effects of inhaled nitric oxide and its combination with intravenous almitrine on Pao2 during one-lung ventilation in patients undergoing thoracoscopic procedures.

UNLABELLED: The aim of this study was to assess whether hypoxemia during one-lung ventilation (OLV) can be prevented by inhaled nitric oxide (NO) (Part I) or by its combination with intravenous (IV) almitrine (Part II) in 40 patients undergoing thoracoscopic procedures. In Part I, 20 patients were divided into two groups: one received O2 (Group 1) and one received O2/NO (Group 2). In Part II, 20 patients were divided into two groups: one received O2 (Group 3) and one received O2/NO/almitrine (Group 4). In Groups 2 and 4, NO (20 ppm) was administered during the entire period of OLV, and almitrine was continuously infused (16 microg x kg(-1) x min[-1]) in Group 4. Arterial blood gases were measured during two-lung ventilation with patients in the supine position, after positioning in the lateral decubitus position, and then every 5 min for a 30-min period during OLV. During OLV, Pao2 values decreased similarly in Groups 1 and 2. After 30 min of OLV, the mean Pao2 values in Groups 1 and 2 were 132 +/- 14 mm Hg (mean +/- sem) and 149 +/- 27 mm Hg (not significant [NS]), and the Pao2 value was less than 100 mm Hg in four patients in Group 1 and five patients in Group 2. Pao2 values were greater in Group 4 than in Group 3 after 15 and 30 min of OLV. After 30 min of OLV, the mean Pao2 values were 146 +/- 16 mm Hg in Group 3 and 408 +/- 33 mm Hg in Group 4 (P < 0.001). Pao2 was less than 100 mm Hg during OLV (NS) in four patients in Group 3 and in no patient in Group 4. We conclude that NO inhalation alone has no effect on Pao2 evolution during OLV, although its combination with IV almitrine limits the decrease of Pao2 during OLV. This beneficial effect of NO/almitrine could be attributed to an improvement in ventilation-perfusion relationships. IMPLICATIONS: Decrease in oxygenation during one-lung ventilation is quite common. Our study showed that inhaled nitric oxide alone did not influence Pao2 evolution. We then tried adding intravenous almitrine to nitric oxide with amazingly good results on Pao2. This nonventilatory technique should be of great use during special thoracic acts, such as thoracoscopic procedures.

Adult

Serotonergic receptors modify the voluntary intake of alcohol and morphine but not of cocaine and nicotine by rats.

Effects of fluvoxamine, a relatively selective 5-HT uptake inhibitor, and ipsapirone, a relatively selective 5-HT1A agonist, were studied on the initiation and/or maintenance of the voluntary intake of alcohol, morphine, cocaine, and/or nicotine in rats using the two-bottle free-choice method. Fluvoxamine (30 mg/kg/day in the drinking fluid) when given during existing morphine consumption increased the intake of this drug (1 +/- 1 vs. 3 +/- 1 mg/kg/day) but had no effect on alcohol (2 +/- 2 vs. 2 +/- 2 g/kg/day) or cocaine (10 +/- 10 vs. 13 +/- 10 mg/kg/day) intake. Ipsapirone (10 mg/kg/day in the drinking fluid) when given during existing alcohol or morphine consumption decreased the intake of the first (2 +/- 2 vs. 1 +/- 1 g/kg/day) and increased the intake of the second drug (2 +/- 1 vs. 4 +/- 1 mg/kg/day), but had no effect on nicotine (1 +/- 1 vs. 1 +/- 1 mg/kg/day) or cocaine (7 +/- 8 vs. 7 +/- 6 mg/kg/day) intake. Ipsapirone when given before exposure to the above drugs reduced subsequent alcohol (2 +/- 1 vs. 1 +/- 1 g/kg/day) and increased subsequent morphine intake (2 +/- 2 vs. 4 +/- 1 mg/kg/day), but had no effect on the voluntary consumption of cocaine (8 +/- 7 vs. 10 +/- 6 mg/kg/day) and nicotine (1 +/- 1 vs. 1 +/- 1 mg/kg/day). These results suggest: (1) selective stimulation of 5-HT1A receptors reduces alcohol preference, (2) stimulation of all 5-HT receptors has no effect on alcohol intake, indicating the presence of inhibitory receptors, (3) stimulation of the serotonergic system in general stimulates morphine preference, (4) the serotonin system does not affect nicotine or cocaine preference and (5) the serotonergic system is not involved in the voluntary consumption of all, but-only of some drugs/chemicals of abuse. Recognition of these drug/chemical-specific sites in the brain might lead to a better understanding of differences in drug abuse patterns among humans and help in the development of specific drugs for the treatment of selective drug addictions.

Alcohol Drinking

[Respiratory response to carbon dioxide after brachial plexus block with fentanyl and lidocaine].

Respiratory parameters, ventilatory response to carbon dioxide and quality of anaesthesia were studied in patients undergoing upper limb surgery under axillary blockade. Thirteen patients were randomly assigned to two groups, group A (n = 6), who were given 35 ml of 1.5% lidocaine with 1 in 200,000 of adrenaline, and group B (n = 7), who received 1 microgram.kg-1 of fentanyl with the same dose of lidocaine. Quality of the sympathetic, sensory and motor blocks were tested at 15 min (T1) and 45 min (T2) after the injection (T0). The other parameters measured at these three times, both with the patient in a half-sitting position breathing room air, and after a rebreathing test with CO2 through Read's circuit, were respiratory rate (FR), tidal volume (VT), minute ventilation (VE), and PetCO2. Fentanyl provided a better sensory and motor blockade at T1, without any difference in sympathetic blockade. The quality of the blocks was similar in both groups at T2. There were no significant differences in the respiratory parameters between the two groups. Moreover, there was no untoward effect due to fentanyl (nausea, pruritus). It is concluded that 1 microgram.kg-1 fentanyl added to a local anaesthetic solution may be useful, at least during the first hour of an axillary block, without any respiratory side-effects.

Adult

Influence of alpha-ketoisocaproate on lamb growth, feed conversion, and carcass composition.

Four experiments were conducted to determine whether leucine's alpha-ketoacid, alpha-ketoisocaproate (KIC), would influence lamb growth, feed conversion, and carcass composition. In the first experiment, lambs were injected intraperitoneally with 3.5 g of Na-KIC per day. In the second experiment, KIC unprotected from rumen degradation was fed at a rate of 15 g per animal daily. In a third experiment, KIC, leucine, and isovalerate (IVA), protected from rumen degradation, were fed to growing lambs at a rate of 1 g per animal per day. Finally, a fourth experiment was conducted in which ruminally protected KIC was fed to growing lambs at a rate of 1 g per animal per day. Ketoisocaproate tended to increase ADG and decrease fat deposition in all four experiments. Ketoisocaproate increased ADG by 11 (P less than .09), 10 (P less than .05), 9, and 13% in 1 through 4, respectively, and feed efficiency improved 5, 9 (P less than .02), 5, and 5%, respectively. Fat thickness over the 12th rib decreased 28 (P less than .06), 11, 17 (P less than .04), and 5% in Exp. 1 through 4, and the perirenal fat depot also decreased 13, 5, 18, and 3%, respectively. In contrast, neither ruminally protected leucine nor IVA affected the growth of young lambs. Together these studies indicate that administration of KIC to growing lambs can increase weight gain and muscle growth while decreasing fat deposition.

Adipose Tissue

Effects of alpha-ketoisocaproate on adrenocorticotropin-induced suppression of lymphocyte function in sheep.

Previous studies of the amino acid analogue, alpha-ketoisocaproate (KIC), indicate that it can stimulate lymphocyte blastogenesis and antibody responses of sheep. To determine whether KIC could overcome the effects of adrenocorticotropic hormone (ACTH)-induced lymphocyte suppression, 24 lambs were fed a control diet, a diet supplemented with 0.05% KIC, or a diet supplemented with 0.05% of the parent amino acid leucine. Immune status was monitored by determining lymphocyte blastogenic responsiveness to phytohemagglutinin-P (PHA), concanavalin A (conA), and pokeweed mitogen (PWM) and percentages of T-cell subsets in the blood, using monoclonal antibodies and a flow cytometer. Serum cortisol, insulin, and glucagon concentrations also were determined. After 60 days of consuming the respective diet, lambs were administered either saline solution or ACTH (100 IU) twice daily for 3 consecutive days. Administration of ACTH increased serum cortisol and insulin concentrations; however, no effects were seen for serum glucagon concentration. Compared with saline administration, ACTH administration significantly (P less than 0.05) suppressed mitogen-stimulated lymphocyte blastogenesis by approximately 50%, regardless of the mitogen used, and significantly (P less than 0.01) decreased the percentage of circulating T lymphocytes and decreased (P less than 0.01) the ratio of T4 to T8 cells. Lambs fed KIC had greater PHA- and conA-stimulated blastogenic responses and significantly (P less than 0.05) increased ratio of T4 to T8 cells in the blood, compared with lambs fed the leucine-supplemented diet or the control diet and given corresponding injections. These data indicate that ACTH decreased in vitro lymphocyte blastogenesis and altered the subset ratios of blood lymphocytes in sheep. These changes were partially prevented by feeding KIC.

Adrenocorticotropic Hormone

Continuous intercostal blockade with lidocaine after thoracic surgery. Clinical and pharmacokinetic study.

The efficacy and the side effects of a continuous infusion of lidocaine in the fifth intercostal space for the management of postoperative pain after lateral thoracotomy were evaluated in 20 adults. An indwelling catheter was inserted in the appropriate intercostal space before thoracotomy closure. After recovery from general anesthesia, a loading dose of 3 mg/kg of 1.5% lidocaine with epinephrine 1:160,000 was injected through the catheter, followed by a continuous infusion of 1% lidocaine without epinephrine at a rate of 1 mg.kg-1.h-1 for 54 h. In seven patients pharmacokinetic data were obtained. Pain, assessed by visual continuous analog scale, decreased from a median score of 8 (range, 7-10) to a score of 5 (range, 2-7) 20 min after the loading dose of lidocaine and continued to decrease until the end of the study (P = 0.0001). Complete cutaneous analgesia, assessed by pinprick test, was seen in a median of three thoracic spinal segments (range, 0-6) with partial cutaneous analgesia in seven segments (range, 6-9) 40 min after the loading dose, and levels that remained unchanged for 54 h (P = 0.0001). Peak lidocaine serum concentrations, 1.9 +/- 0.7 micrograms/mL, were present 9 +/- 3 min after injection of the loading dose. Serum concentrations of lidocaine under steady state conditions averaged 4.8 +/- 0.9 micrograms/mL (range, 3.5-5.8 micrograms/mL). This level under steady state conditions, though below the toxic level, suggests that additional bolus injection of lidocaine during the course of infusion might result in potentially toxic serum levels of lidocaine.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult

Effects of dietary leucine, alpha-ketoisocaproate and isovalerate on antibody production and lymphocyte blastogenesis in growing lambs.

The chronic effects of oral leucine and leucine metabolites on sheep immune function were determined in two experiments. In replicate experiments, 30 mixed-breed ram lambs were individually fed diets supplemented with approximately 0.05% ruminally protected limestone (control), alpha-ketoisocaproate (KIC), isovalerate (IVA) or leucine (Leu). Serum titers of antibodies produced in response to Brucella abortus antigen and porcine red blood cells were determined. Mitogen-stimulated lymphocyte blastogenesis was determined in experiment 2 by adding phytohemagglutinin (PHA), concanavalin A (Con A) or pokeweed mitogen (PWM) to isolated lymphocytes and measuring [3H]thymidine incorporation. In both experiments, in lambs fed Leu, antibody production to porcine red blood cells was approximately 80% (P less than 0.05) of that in control animals. When KIC was fed, antibody titers to porcine red blood cells were approximately 120% (P less than 0.05) of that of controls. Compared to controls background lymphocyte blastogenesis was higher when KIC was fed, whereas background blastogenesis was lower when Leu was fed (KIC vs. Leu; P less than 0.05). IVA did not significantly affect either measurement. These data indicate that feeding Leu may adversely affect immune function by suppressing lymphocyte activity, whereas oral administration of KIC has a positive influence on immune function in sheep by increasing lymphocyte activity.

Animals

Evaluation of weight loss protocols for dogs.

Several canine weight loss protocols were evaluated to determine their relative safety and efficacy. Dogs were fed 100%, 75%, 60%, or 50% of maintenance energy requirements (MERs) using the dogs' target body weights. No indications of adverse health effects were observed with any weight loss protocol. Triiodothyronine (T3) levels and apparent MERs decreased in dogs restricted to 50% to 60% of their MERs. The rate of weight loss was correlated linearly with degree of calorie restriction, although there was considerable individual variation. Percent overweight by the end of the test was not different between protocol groups for dogs fed 50%, 60%, or 75% of MERs. Therefore, any of the protocols tested in this study may be used in the management of overweight dogs; however, individual responses will be expected to vary, and severe calorie restriction may predispose dogs to weight rebound.

Animals

Addition of fentanyl to 1.5% lidocaine does not increase the success of axillary plexus block.

BACKGROUND AND OBJECTIVES: This randomized, double-blind study was designed to evaluate the effects of the addition of fentanyl (F) to lidocaine (L) on the onset, duration, and success rate of axillary brachial plexus block. METHODS: After institutional approval and informed consent, 53 ASA 1 and ASA 2 patients scheduled for orthopedic surgery using brachial plexus anesthesia were included in the study. Axillary brachial plexus block was performed using a peripheral nerve stimulator to localize one nerve of the major plexus. The patients were randomly allocated to two groups. The L + F group (n = 27) were administered 38 mL of 1.5% L with 1/200,000 epinephrine and 100 micrograms of F, and the L + S group (n = 26) were administered 38 mL of 1.5% L with 1:200,000 epinephrine and 2 mL of normal saline. The onset (monitored every 5 minutes) and duration (monitored every 30 minutes) of surgical anesthesia, defined as the total abolition of the pinprick response, were evaluated in each nerve territory. RESULTS: The patients were similar with regard to demographic data and the nerve trunks stimulated. In the L + F group, the onset time was only reduced (P = .012) for the musculocutaneous nerve. The duration of surgical anesthesia and the motor block were similar in both groups. The frequency of complete plexus block and the frequency of anesthesia for each nerve trunk were similar in both groups. CONCLUSION: There is no clinical benefit resulting from the addition of fentanyl to the local anesthetic for axillary brachial plexus block.

Adult