Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0012833 (dizziness)
 9,689 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Sixty-four climbers participated in a randomized clinical trial of acetazolamide prophylaxis for acute mountain sickness (AMS) during rapid, active ascent of MT Rainier. Twenty-nine (93.6%) of 31 climbers receiving acetazolamide and 25 (75.8%) of 33 receiving placebo attained the summit. Time spent ascending from sea level to the summit (4,394 m) averaged 33.5 hours (range, 23 to 48 hours). On the summit AMS was less common in climbers receiving acetazolamide, and they experienced less headache, nausea, drowsiness, shortness of breath, and dizziness and a greater sense of satisfaction and psychological well-being. Minute ventilation on the summit was significantly greater in subjects taking acetazolamide (24.9 +/- 2.0 L/min compared with 16.9 +/- 3.8 L/min). Expired vital capacity was also greater on the summit in the acetazolamide group (6.9 +/- 0.4 L compared with 5.8 +/- 0.4 L). We conclude that acetazolamide is effective in the prophylaxis of AMS for climbers attempting rapid, active ascent. Increased ventilation at altitude, producing an increased alveolar oxygen tension, may be related to the observed amelioration of symptoms.
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PMID:Acute mountain sickness and acetazolamide. Clinical efficacy and effect on ventilation. 704 33

When divers are exposed to extreme atmospheric pressures they may exhibit symptoms of the high pressure nervous syndrome (HPNS). Although clinical HPNS symptoms are well described, little is known about the underlying pathophysiologic mechanisms. Special HPNS signs like vertigo and tremor suggested sensory-motor hyperexcitability resulting from brainstem dysfunction. We therefore studied brainstem auditory evoked potential (BAEP) repeatedly in four divers during an experimental deep helium-oxygen saturation dive to 450 meters of seawater (msw). Wave I (auditory nerve response) latency decreased whereas interpeak latencies (IPLs) I-III and I-V, which indicate respective cochleo-pontine and cochleo-mesencephalic transmission time, prolonged during the dive. IPLs III-V also prolonged the dive, but with greater variability among divers. Two divers showed a marked reversal of the normal attenuation effect of increased stimulus presentation rates on IV and V amplitudes during compression, an effect that subsided during the stay at bottom depth. This finding might indicate a relative enhancement of synaptic excitability and is presumed to be a feature of HPNS. Wave I latency reduction might at least partly be caused by accelerated sound conduction in dense helium. Additionally, an upward shift of middle ear resonance frequencies in helium can induce a basal shift of the main cochlear portion responding to the wide band clicks. This effect may reduce wave I latency due to greater relative input from the basal high frequency-short latency-cochlear neurons. Pressure-induced decrease of nerve conduction velocity, delay of synaptic transmission, and inhibitory modulation of midbrain auditory afferents possibly contributed to observed interpeak latency prolongations. Clinical HPNS signs, such as tiredness, dizziness, postural and intentional hand tremor, ataxia, and opsoclonus, were noted in three divers after reaching 300 msw and continued throughout the 37-h stay at bottom depth.
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PMID:Brainstem auditory evoked potentials during a helium-oxygen saturation dive to 450 meters of seawater. 758 Jul 64

Carbon monoxide poisoning usually results from inhalation of exhaust fumes from motor vehicles, smoke from fires or fumes from faulty heating systems. Carbon monoxide has a high affinity for hemoglobin, with which it forms carboxyhemoglobin. The resulting decrease in both oxygen-carrying capacity and oxygen release can lead to end-organ hypoxia. The clinical presentation is nonspecific. Headache, dizziness, fatigue and nausea are common in mild to moderate carbon monoxide poisoning. In more severe cases, tachycardia, tachypnea and central nervous system depression occur. When carbon monoxide intoxication is suspected, empiric treatment with 100 percent oxygen should be initiated immediately. The diagnosis is confirmed by documenting an elevated carboxyhemoglobin level. Hyperbaric oxygen therapy is recommended in patients with neurologic dysfunction, cardiac dysfunction or a history of unconsciousness.
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PMID:Carbon monoxide intoxication. 769 50

The authors studied the efficacy and cost of substituting sedation using midazolam and alfentanil for the existing regimen of diazepam and meperidine in patients requiring upper gastrointestinal endoscopy. Sixty consenting subjects were randomized to receive either meperidine 50 mg with diazepam approximately 90 micrograms.kg-1 (Group D) or alfentanil 250 micrograms with midazolam approximately 50 micrograms.kg-1 (Group M). Endoscope insertion time, patient acceptance, apnoeic or desaturation episodes were noted by a physician observer. Pulse oximetry was used to monitor heart rate and oxygen saturation (SpO2) during endoscopy. Subjects performed four-choice reaction time (4CRT) tests before, 30 and 60 min after endoscopy, and were assessed for nausea or dizziness and their ability to stand and walk. During endoscopy, insertion time was shorter (84 +/- 45 sec vs 122 +/- 83 sec, P < 0.03) and fewer aversive movements occurred (0.4 +/- 0.6 vs. 1.7 +/- 2.4, P < 0.005) in Group M than Group D. No subject in either group suffered any apnoea or prolonged desaturation requiring supplemental oxygen. Irrespective of treatment group, greater decreases in SpO2 (6.1 +/- 3.4% vs 3.6 +/- 2.2% P < 0.001) occurred in subjects > 45 yr of age than in subjects < or = 45 yr. During recovery 4CRT values at 30 min after endoscopy were longer (723 +/- 226 msec vs 594 +/- 139 msec, P < 0.005) in Group M than in Group D but not after 60 min. It was concluded that the small differences in endoscopy conditions and greater sedation during the first 30 min of recovery did not justify the additional cost of using midazolam and alfentnil.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Sedation for upper gastrointestinal endoscopy: a comparison of alfentanil-midazolam and meperidine-diazepam. 786 9

Abuse of intravenous crushed Talwin (pentazocine) and Ritalin (methylphenidate) tablets has not been fully described. The objective of this study was to characterize intravenous pentazocine/methylphenidate abuse in emergency department patients and compare its clinical toxicity to pentazocine/tripelennamine. Cases of intravenous pentazocine/methylphenidate abuse presenting to the Truman Medical Center Emergency Department between August 1987 and November 1992 were identified. Information regarding patient demographics, drug abuse, chief complaints, evaluation, treatment, and disposition were obtained from the emergency department record. The clinical presentation was compared to 104 published cases of pentazocine/tripelennamine abuse. Twenty nine patients were treated 34 times. They were 32 +/- 9 years of age, 48% male, and 52% black. Patients' chief complaints were cardiovascular/pulmonary (N = 8), central nervous system (N = 7), localized infection (N = 7), gastrointestinal (N = 5), malaise (N = 5), trauma (N = 1), and gynecologic (N = 1). Treatment was primarily supportive and included supplemental oxygen and intravenous fluids. The clinical findings were similar to those reported for pentazocine/tripelennamine; 58% had the typical symptom complex of chest pain, anxiety, muscle spasm, dizziness, and nausea.
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PMID:IV pentazocine/methylphenidate abuse--the clinical toxicity of another Ts and blues combination. 793 13

Sevoflurane is a "new" volatile inhaled anaesthetic that is currently undergoing phase III clinical trial in Europe and the United States. Owing to the low blood solubility, rapid induction of anaesthesia and emergence from anaesthesia would be expected. In this study, we compared emergence times and haemodynamics in patients receiving either sevoflurane or isoflurane. Furthermore, all adverse effects were recorded and the relationship to the drug administered was rated. METHODS. Fifty ASA physical status I and II patients were studied in an open, prospective, randomised clinical trial. Anaesthesia was induced with fentanyl, thiopentone, and vecuronium for facilitating endotracheal intubation and maintained with sevoflurane or isoflurane, 60% nitrous oxide (N2O) in oxygen (O2), and additional doses of fentanyl (1-2 micrograms/kg.h). The electrocardiogram, blood pressure (non-invasive), O2 saturation, temperature, and end-tidal concentrations of sevoflurane or isoflurane, N2O, and carbon dioxide were monitored continuously. At the end of surgery, administration of sevoflurane or isoflurane and N2O was discontinued without tapering and emergence times were recorded. All adverse events that occurred until the 3rd postoperative day were recorded and the relationship to the inhaled anaesthetic was rated as "none", "unlikely", "possible", "probable", or "highly probable". RESULTS. With the exception of gender, the two patient groups were comparable (Tables 1 and 2). Due to the higher MAC value, mean end-tidal concentrations were higher for sevoflurane (0.82% vs. 0.59% for isoflurane). The duration of anaesthetic exposure was 1.3 MAC h (calculation with FIO2 = 1.0 MAC value) and 3.1 MAC h (calculation with FIO2 = 0.4 in N2O MAC value), respectively, for both inhaled anaesthetics. Pulmonary elimination was faster (Fig. 1) and emergence time shorter (7 min vs. 11.5 min, Table 3) with sevoflurane. There was no difference in the time courses of heart rate and mean arterial blood pressure (Figs. 2 and 3). No adverse effects with a "probable" or "highly probable" relationship to the inhaled anaesthetic were observed. Table 4 shows the adverse events with a possible relationship to the drug administered. Further evaluations of nausea, vomiting, and dizziness are shown in Table 5. DISCUSSION. Emergence time after inhalation anaesthesia depends on pulmonary elimination and MACawake, that is, the end-tidal concentration that would allow opening of the eyes on verbal command. Pulmonary elimination depends on dose applied (MAC h), alveolar ventilation, and blood-gas solubility coefficient. Due to the lower blood-gas solubility coefficient (0.6-0.7 for sevoflurane vs. 1.3-1.4 for isoflurane) and in accordance with the investigations of Frink et al. [4] and Smith et al. [16], emergence time was significantly shorter with sevoflurane. Gender, the only difference between the two patient groups, does not influence pulmonary elimination and MACawake [8]. Supplementing inhalation anaesthesia with fentanyl, there was no difference in the time courses of heart rate and mean arterial blood pressure between sevoflurane and isoflurane. Adverse events with a possible relationship to the inhaled anaesthetic occurred in both groups.
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PMID:[Emergence times, hemodynamics and adverse effects of sevoflurane and isoflurane: an open, randomized, comparative phase iii study]. 797 85

At presentation the history of an 87-year-old woman included progressive memory loss, repeated transient ischaemic attack, increasing fatigue, dizziness, palpitations and frequent falls. Investigations revealed erythrocytosis, leukocytosis, thrombocytosis, normal arterial oxygen concentration and an increased red cell volume. Polycythaemia vera was diagnosed and was successfully managed by phlebotomy with half a unit twice a week and rechecks of her haematocrit, initially; she reported marked improvement after 2 weeks of treatment. The alternative treatments for polycythaemia vera are discussed; in addition to venesection, conventional treatments include bone-marrow depressive agents such as phosphorus-32 and chemotherapy with agents such as hydroxyurea. More recent developments include isovolumic erythrocytophoresis, alpha-interferon and ticlopidine. All of the treatments are associated with complications, or other disadvantages, thrombotic complications in the case of phlebotomy, malignancies in the case of most myelosuppressive treatments, and problems of compliance in others. The optimal treatment for polycythaemia vera is a judicious combination of the alternatives, depending on the phase of the disease, the age of the patient, and other prognostic factors.
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PMID:Primary polycythaemia vera in the elderly. 802 Jun 39

Nineteen workers (18 males, 1 female) of a garbage dump (mean age 39.9 years, range 19-58 years) were admitted to our hospital because of inhalation of a hydrazine-like gas of unknown origin. They complained of an ammoniacal odor with sweet taste followed by burning of the eyes, rawness in the throat and dyspnea, dizziness and nausea. Ten patients (group A) arrived about 2 h after they had experienced their first symptoms. The nine other patients (group B) were admitted about 70 h later. On the second day the white cell counts were significantly elevated compared to those of the days before and after (P < 0.02-0.005). The lung function showed in two patients a moderate obstruction. The PO2 was significantly reduced within 1 to 12 h after admission (P < 0.02-0.005) compared to the measurement before (P < 0.005) and after 25 (P < 0.02) and 50 (P < 0.01) h. A significantly reduced PCO2 was found after 25 h compared to the time of admission (P < 0.03). These investigations show that workers of a garbage dump had an alarming decrease of oxygen after inhalation of nitrogenous gases released by the trash.
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PMID:Acute intoxication of a hydrazine-like gas by 19 workers in a garbage dump. 811 90

Four patients showing classic physical stigmata of traumatic asphyxia were studied. Cervicofacial cyanosis and edema, subconjunctival hemorrhage, and multiple ecchymotic hemorrhage of the face, neck, and upper part of the chest were documented. Admission Glasgow coma scale scores ranged from 8 to 15. All but one had no associated injury. Skin discoloration resolved within 3 weeks. Complete resolution of subconjunctival hemorrhage occurred 1 month later. In our series, sore throat, hoarseness, dizziness, numbness, and headaches were common. Profound lower leg pitting edema, hemoptysis, hemotympanum, and transient visual loss were noted. Chest radiographic findings were normal in all patients. Microscopic hematuria was noted in one patient. Diagnosis is made from the history and characteristic appearance of the patient. Treatment is directed to the associated injury. Oxygen supplement with head elevation to 30 degrees is the mainstay of treatment. If the patient survives the initial insult, the prognosis is excellent.
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PMID:Traumatic asphyxia. 813 32

A 24-year-old oil well tester was rendered semiconscious by hydrogen sulfide (H2S). He received oxygen and was hospitalized but released in 30 minutes. The next day, nausea, vomiting, diarrhea, and incontinence of urine and stool led to rehospitalization. These problems and leg shaking, dizziness, sweating, trouble sleeping, and nightmares prevented his return to work. A physical examination, chest x-ray, and pulmonary function tests were normal 39 months after the episode but vibration sense was diminished. Two choice visual reaction times were delayed. Balance was highly abnormal (5 to 6 cm/sec) with eyes closed. Blink reflex latency was slow (R-1 17.5 msec versus normal 14.3 msec). Numbers written on finger tips were not recognized. Verbal and visual recall were impaired but overlearned memory was intact. Cognitive functions measured by Culture Fair, block design, and digit symbol were impaired. Perceptual motor was slow. Scores for confusion, tension-anxiety, depression, and fatigue were elevated and vigor was reduced. Forty-nine months after exposure his reaction time, sway speed, and color vision had not improved. His recall and his cognitive, constructional, and psychomotor speeds had improved but remained abnormal. These deficits are most likely due to H2S. Similar testing of other survivors is recommended.
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PMID:Case report: profound neurobehavioral deficits in an oil field worker overcome by hydrogen sulfide. 823 84


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