Malignant hyperthermia 2020: Guideline from the Association of Anaesthetists.

Malignant hyperthermia is defined in the International Classification of Diseases as a progressive life-threatening hyperthermic reaction occurring during general anaesthesia. Malignant hyperthermia has an underlying genetic basis, and genetically susceptible individuals are at risk of developing malignant hyperthermia if they are exposed to any of the potent inhalational anaesthetics or suxamethonium. It can also be described as a malignant hypermetabolic syndrome. There are no specific clinical features of malignant hyperthermia and the condition may prove fatal unless it is recognised in its early stages and treatment is promptly and aggressively implemented. The Association of Anaesthetists has previously produced crisis management guidelines intended to be displayed in all anaesthetic rooms as an aide memoire should a malignant hyperthermia reaction occur. The last iteration was produced in 2011 and since then there have been some developments requiring an update. In these guidelines we will provide background information that has been used in updating the crisis management recommendations but will also provide more detailed guidance on the clinical diagnosis of malignant hyperthermia. The scope of these guidelines is extended to include practical guidance for anaesthetists dealing with a case of suspected malignant hyperthermia once the acute reaction has been reversed. This includes information on care and monitoring during and after the event; appropriate equipment and resuscitative measures within the operating theatre and ICU; the importance of communication and teamwork; guidance on counselling of the patient and their family; and how to make a referral of the patient for confirmation of the diagnosis. We also review which patients presenting for surgery may be at increased risk of developing malignant hyperthermia under anaesthesia and what precautions should be taken during the peri-operative management of the patients.

Electrophysiological Study of Nerves in Type-II Reaction in Leprosy.

BACKGROUND: Leprosy is a chronic granulomatous infection primarily affecting the peripheral nervous system, skin and reticuloendothelial system. Cutaneous nerves are severely affected in lepra reaction and this leads to morbidity. OBJECTIVE: To study electrophysiological pattern of different nerves involved in Type-II reactions in leprosy. METHOD: The present study was undertaken in 21 leprosy patients with Type-II reactions attending in and out-patient department of Dermatology & Venereology, B.R.D. Medical College, Gorakhpur from July 2005 to October 2006. This was a prospective case control study in which 20 healthy, age and sex matched people with no evidence of any disease (particularly nerve involvement) were included. LIMITATION: Lesser number of cases were studied. RESULT: The proximal motor conduction latency was significantly prolonged in both ulnar and common peroneal nerve and proximal motor conduction velocity was also significantly reduced. On examining the values beyond 2S.D. of the control value, distal latency was not affected and only proximal conduction was affected in ulnar nerve. CONCLUSION: In Type II lepra reaction the motor conduction abnormalities are not prominent. Abnormalities are relatively more marked in the proximal segment.

The BMP family member Gdf7 is required for seminal vesicle growth, branching morphogenesis, and cytodifferentiation.

Epithelial-mesenchymal interactions play an important role in the development of many different organs and tissues. The secretory glands of the male reproductive system, including the prostate and seminal vesicles, are derived from epithelial precursors. Signals from the underlying mesenchyme are required for normal growth, branching, and differentiation of the seminal vesicle epithelium. Here, we show that a member of the BMP family, Gdf7, is required for normal seminal vesicle development. Expression and tissue recombination experiments suggest that Gdf7 is a mesenchymal signal that acts in a paracrine fashion to control the differentiation of the seminal vesicle epithelium.

Hypoxemia and elevated tachykinins in rat monocrotaline pneumotoxicity.

This study was performed to test whether monocrotaline (MCT)-induced early airway dysfunction and gas exchange abnormalities result in arterial hypoxemia. Thirty young male Sprague-Dawley rats were divided into four groups: control, MCT1, MCT2, and MCT3. Each of the control animals was injected (subcutaneously) with saline; each of the MCT rats was injected with MCT (60 mg/kg, subcutaneously). The rats were tested 1 (MCT1), 2 (MCT2), or 3 (MCT3) weeks after MCT injection. Two days before each animal was tested, it was anesthetized with sodium pentobarbital, and its carotid artery was chronically cannulated. Blood was sampled from the arterial catheter of the conscious rat, and blood gases and pH were measured. Pulmonary arterial pressure (Ppa) was determined in the anesthetized, open chest animal. Heart weight was measured and a weight ratio obtained of right ventricle (RV) to left ventricle plus septum (LV+S). The amount of lung substance P and airway neutral endopeptidase (NEP) activity were also measured. MCT significantly decreased arterial oxygen tension (Pao2) and increased the RV/(LV+S) weight ratio 2 and 3 weeks after administration, whereas it did not significantly increase Ppa until 3 weeks after injection. MCT significantly increased lung substance P levels and decreased airway NEP activities 1-3 weeks after administration. These data suggest that tachykinins cause hypoxemia and RV hypertrophy; then hypoxia may augment the development of pulmonary hypertension.

Capsaicin pretreatment attenuates chronic hypoxic pulmonary hypertension.

Capsaicin pretreatment was used to deplete tachykinins in order to study the role of tachykinins in chronic hypoxia-induced pulmonary hypertension. Forty three young Wistar rats weighing 235 +/- 4 g were randomly divided into four groups: control (n = 10); capsaicin pretreatment (n = 10); intermittent chronic hypoxia (n = 10); and capsaicin pretreatment + intermittent chronic hypoxia (n = 13). Control animals breathed room air. Rats in the capsaicin pretreatment groups were given capsaicin via subcutaneous injection over a three-day period. Hypobaric hypoxia was intermittently applied by placing animals into a hypobaric chamber with a barometric pressure of 380 Torr for two weeks. In the capsaicin pretreatment + intermittent chronic hypoxia group, rats were exposed to intermittent hypoxia for two weeks immediately after the last dose of capsaicin. Subsequently, pulmonary vascular function, as well as substance P (a tachykinin) level and neutral endopeptidase (NEP, the major degradation enzyme for tachykinins) activity in the lungs were measured. Chronic hypoxia caused significant increases in pulmonary artery pressure, right ventricle/(left ventricle + septum) weight ratio, hematocrit, and lung substance P level, as well as a significant decrease in lung NEP activity. All these chronic hypoxia-induced changes were significantly lessened by capsaicin pretreatment. Capsaicin pretreatment alone did not induce any significant alteration in vascular function. These results suggest that the chronic hypoxia causes an increase in lung tachykinin levels which, in turn, enhance the development of pulmonary hypertension.

Sidestream cigarette smoke exposure and airway reactivity during early life.

We established a guinea pig model to investigate effects of in utero and neonatal exposure to sidestream cigarette smoke (SSCS) on bronchial reactivity during early life. Animals were divided into four groups: 1) room air/room air, 2) sham/sham, 3) SSCS/room air, and 4) SSCS/SSCS. Pregnant and neonatal animals of group 1 breathed room air and those of group 2 were sham treated. Pregnant animals of both groups 3 and 4 as well as neonates of group 4 were exposed to SSCS. SSCS exposure was limited to between days 28 and 55 of pregnancy and days 8 and 24 of the neonatal period. Bronchial response to acetylcholine (ACh) and substance P (SP) were determined in very young animals at 25 days of age. Maximal expiratory flow was used as an index of airway dimension. SP, but not ACh, induced a significantly larger decrease in peak maximal expiratory flow in group 4, indicating an important role of neonatal SSCS exposure in augmenting bronchial response to SP. To further investigate the role of tachykinins in cigarette smoke-induced changes in bronchial reactivity, four additional groups (the same as above) of neonates were pretreated with capsaicin to deplete tachykinins. In the SSCS/SSCS group, SP-induced airway hyperreactivity was abolished by capsaicin pretreatment. Furthermore, in all four groups, capsaicin pretreatment abolished the bronchial response to SP but not the response to ACh. In additional very young animals, acute SSCS caused a nonsignificant increase in bronchial response to SP. These results indicate that chronic neonatal SSCS exposure induces bronchial hyperreactivity to SP; this hyperreactivity is abolished by capsaicin pretreatment.

Disappearing CT lesion in a nonepileptic patient.

Despite its high incidence, the exact cause of disappearing CT lesions in patients with epilepsy is not clear. We document a non-epileptic patient, whose clinical picture simulated idiopathic intracranial hypertension, but CT showed a spontaneously resolving ring enhancing lesion.

Epidemiology of idiopathic intracranial hypertension: a prospective and case-control study.

An epidemiologic survey of idiopathic intracranial hypertension (IIH) in Benghazi, Libya, over a period from September 1982 through August 1989 ascertained 81 patients. The group was comprised of 76 females and 5 males. Ages ranged from 8 to 55 years; the mean +/- S.D. was 28.6 +/- 7.9 for women and 21.0 +/- 14.5 for men. The average crude annual incidence rates for IIH per 100,000 persons were 2.2 for the total and 4.3 for females for all ages (3.2 for the total and 5.9 for the females when adjusted to the 1980 United States population). In females aged 15-44 years, IIH occurred at a rate of 12.0 per 100,000 per year; for those defined as obese, the rate rose to 21.4. Moderate to severe visual loss occurred as a sequelae in 20% of our patients. The extent of visual loss did not correlate with age at diagnosis, duration of symptoms, degree of obesity, use of oral contraceptive pills, cerebrospinal fluid (CSF) opening pressure, steroid treatment, or recurrence. We found no correlation between CSF protein and opening pressure. We conducted a case-control study on 40 consecutive female incident IIH patients and 80 age-matched female control subjects. Obesity and recent weight gain occurred more frequently in patients. More patients were married and more had irregular menses. The incidence rate for IIH described in our study is three to four times higher than that reported from the United States.

Neuroleptic malignant syndrome in a girl without psychosis.

We report a successfully managed case of neuroleptic malignant syndrome in which the diagnosis was delayed by one week because of the absence of an established psychiatric disease. A high degree of clinical suspicion must be maintained if the diagnosis of this rare, curable but often fatal, complication of neuroleptic therapy is not to be missed.

Fluorotic radiculomyelopathy in a Libyan male.

A middle-aged male resident of Benghazi, northeastern Libya, with radiological features of skeletal fluorosis associated with cervical radiculomyelopathy is reported. This is believed to be the first documentation of such a disorder from this non-tropical, non-endemic region.

Descriptive epidemiology of some rare neurological diseases in Benghazi, Libya.

During a 4-year study period, January 1983 to December 1986, 24 patients (18 index cases) with spinal muscular atrophy (hereditary motor neuropathy, HMN), 9 with myasthenia gravis (MG), 6 with progressive supranuclear palsy (PSP), and 5 with subacute sclerosing panencephalitis (SSPE) were diagnosed in Benghazi. The HMN group comprised 6 acute infantile, 12 chronic childhood, and 3 each with adult-onset proximal, and distal forms of the disease. The crude average annual incidence of acute infantile HMN was 0.3/100,000 total population and 1/12,500 births in Benghazi. The crude prevalence rates of chronic childhood, adult-onset proximal, and distal types of HMN were 2.3, 0.6 and 0.6/100,000, respectively. The larger family size and the high rate of consanguineous marriages contribute to the high frequency of HMN in the study area. Distal HMN constituted 12.5% of the total cases. The adjusted average incidence of MG was 4.4/million/year, 2.1 for males and 6.8 for females. The female:male incidence ratio was 3.2:1. The crude average annual incidence rates/million inhabitants for PSP asnd SSPE were 3 and 2.4, respectively. The frequency of occurrence of SSPE among the subtropical Arab community under investigation is comparable with other surveys from the Middle East and Mediterranean region.

Muscle dysfunction in male hypogonadism.

Twenty-eight consecutive male patients with primary and secondary hypogonadism (14 each) were evaluated clinically and electrophysiologically for muscle dysfunction. Although generalised muscle weakness was initially reported by only 9 patients, on direct questioning, it was recorded in 19. Objective weakness was found in 13 patients and it involved both the proximal and distal limb muscles. Quantitative electromyography showed evidence of myopathy in the proximal muscle in 25 patients, i.e., reduced MUP duration and amplitude with increased polyphasia in the deltoid and the gluteus maximus. There were no denervation potentials. None of the patients showed clinical neuropathy or NCV abnormalities. Thus, the profile of muscle involvement in hypogonadism closely simulates limb-girdle muscular dystrophy and other endocrine myopathies. The incidence of muscle involvement was higher in secondary hypogonadism. Diminished androgens in primary hypogonadism and diminished growth hormone in the secondary hypogonadism are probably responsible for the myopathy.