Randomised trial of intravenous infusion of ephedrine or mephentermine for management of hypotension during spinal anaesthesia for Caesarean section

This study compared the effects of intravenous infusions of ephedrine and mephentermine for maintenance of maternal arterial pressure and neonatal outcome in pregnant women receiving subarachnoid block for lower segment Caesarean section. Sixty patients who developed hypotension following subarachnoid block for Caesarean section were randomly divided into two groups of 30 each to receive an intravenous infusion of ephedrine or mephentermine. Hypotension was defined as a decrease in systolic blood pressure of > or = 20% from the baseline value or an absolute value of <100 mmHg, whichever was higher. The vasopressor infusion was titrated to maintain systolic blood pressure between 'hypotension' and baseline values. Baseline haemodynamic parameters, haemodynamic changes subsequent to the start of vasopressor infusion, duration of hypotension and amount of vasopressor required were statistically similar for both groups. Neonatal APGAR scores and acid-base profiles were also comparable. To conclude, mephentermine can be used as safely and effectively as ephedrine for the management of hypotension during spinal anaesthesia in patients undergoing elective Caesarean section.

Effect of diclofenac pretreatment on pain during propofol injection

In a randomized, double-blind, controlled trial, 120 ASA 1 or 2 patients were allocated to receive diclofenac or normal saline as pretreatment to assess their effect on incidence and severity of pain during propofol injection. Diclofenac in two different doses, i.e. 25 mg and 15 mg, was tried for this purpose. The overall incidence of pain did not significantly differ among the groups, but the incidence of moderate to severe pain following propofol injection was significantly less in patients who received diclofenac 25 mg (P = 0.0017) or 15 mg (P = 0.0363) than in those who received saline. However, the diclofenac itself was associated with mild pain in some patients.

Filters in anaesthesia and intensive care

The use of various types of filters in anaesthesia and intensive care seems ubiquitous, yet authentication of the practice is scarce and controversies abound. This review examines evidence for the practice of using filters with blood and blood product transfusion (standard blood filter, microfilter, leucocyte depletion filter), infusion of fluids, breathing systems, epidural catheters, and at less common sites such as with Entonox inhalation in non-intubated patients, forced air convection warmers, and air-conditioning systems. For most filters, the literature failed to support routine usage, despite this seemingly being popular and innocuous. The controversies, as well as guidelines if available, for each type of filter, are discussed. The review aims to rationalize the place of various filters in the anaesthesia and intensive care environment.

Psychological care in trauma patients

The clinician manages trauma patients in the emergency room, operation theatre, intensive care unit and trauma ward with an endeavour to provide best possible treatment for physical injuries. At the same time, it is equally important to give adequate attention to behavioural and psychological aspects associated with the event. Knowledge of the predisposing factors and their management helps the clinician to prevent or manage these psychological problems. Various causes of psychological disturbances in trauma patients have been highlighted. These include pain, the sudden and unexpected nature of events and the procedures and interventions necessary to resuscitate and stabilise the patient. The ICU and trauma ward environment, sleep and sensory deprivation, impact of injury on CNS, medications and associated pre-morbid conditions are also significant factors. Specific problems that concern the traumatised patients are helplessness, humiliation, threat to body image and mental symptoms. The patients react to these stressors by various defence mechanisms like conservation withdrawal, denial, regression, anger, anxiety and depression. Some of them develop delirium or even more severe problems like acute stress disorder or post-traumatic stress disorder. Physical, pharmacological or psychological interventions can be performed to prevent or minimise these problems in trauma patients. These include adequate pain relief, prevention of sensory and sleep deprivation, providing familiar surroundings, careful explanations and reassurance to the patient, psychotherapy and pharmacological treatment whenever required.

Respiratory failure in acute intermittent porphyria

We report two patients of acute intermittent porphyria (AIP) who presented with acute respiratory failure. Only one such previous report could be found. Occasionally, neuropathy may be the presenting feature in AIP which may progress to respiratory embarrassment. The cause of this neuropathy has been hypothesized to be direct neurotoxicity of delta-ALA by interaction with GABA receptor, altered tryptophan metabolism and may be heme depletion in nerve cells.

Comparison of isoprenaline with adrenaline as components of epidural test dose solutions for halothane anaesthetized children

In this randomized controlled trial we studied the haemodynamic effects of intravenous injection of lignocaine 1 mg/kg with either no additive, isoprenaline 0. 05 microg or 0.075 microg/kg, or adrenaline 0.5 microg/kg in children anaesthetized with halothane. An increase of > or = 10 bpm in heart rate or > or = 20% rise in blood pressure was taken as a positive test response. Adrenaline was confirmed to be an unreliable marker with a positive test in only 67% of cases. For both doses of isoprenaline, the heart rate changes produced a positive test in 100% of cases. There was no statistically significant difference between the two doses of isoprenaline in regard to mean maximum increase in heart rate, mean time of beginning, ending or duration of positive test response and mean time to reach peak heart rate. The positive test response began between 10 and 50 seconds and lastedfor an average of 69 +/- 54 seconds with the lower dose of isoprenaline 0.05 microg/kg No advantage could be seen with the higher dose of isoprenaline. Change in blood pressure was not a useful criterion to detect intravascular injection. Recommendations for the use of isoprenaline as a marker of intravascular injection during regional blockade must be deferred until the safety of this agent's effect on neurological tissue is confirmed.

Time to initiating highly active antiretroviral therapy among HIV-infected injection drug users

OBJECTIVE

Studies have shown that HIV-infected injection drug users (IDUs) are less likely to receive antiretroviral therapy than non-drug users. We assess factors associated with initiating highly active antiretroviral therapy (HAART) in HIV-infected IDUs.

METHODS

A cohort study of IDUs carried out between 1 January 1996 and 30 June 1999 at a community-based study clinic affiliated to the Johns Hopkins University, Baltimore, Maryland. The participants were a total of 528 HIV-infected IDUs eligible for HAART based on CD4+ cell count. The main outcome measure was the time from treatment eligibility to first self-reported HAART use, as defined by the International AIDS Society-USA panel (IAS-USA) guidelines.

RESULTS

By 30 June 1999, 58.5% of participants had initiated HAART, most of whom switched from mono- or dual-combination therapy to a HAART regimen. Nearly one-third of treatment-eligible IDUs never received antiretroviral therapy. Cox proportional hazards regression showed that initiating HAART was independently associated with not injecting drugs, methadone treatment among men, having health insurance and a regular source of care, lower CD4+ cell count and a history of antiretroviral therapy.

CONCLUSIONS

Self-reported initiation of HAART is steadily increasing among IDUs who are eligible for treatment; however, a large proportion continues to use non-HAART regimens and many remain treatment-naive. Although both groups appear to have lower health care access and utilization, IDUs without a history of antiretroviral therapy use would have more treatment options available to them once they become engaged in HIV care.

What is the effect of riskshaw noise on its driver?

OBJECTIVE

Occupational hearing loss is common in the industrialized world. Road noise is a major contributor to perceived environmental noise. The objective of this study was to assess hearing loss in rickshaw drivers due to rickshaw noise.

METHODS

Hearing loss in rickshaw drivers and taxi drivers of Karachi who were 50 years of age or younger was estimated, with a Smith Hearing Screening (SHS) questionnaire that was modified, translated into the national language, Urdu and field tested prior to administration.

RESULTS

Interviews for 91 rickshaw drivers and 94 taxi drivers were completed. All subjects were male; mean ages were 34 and 33 years for rickshaw and taxi drivers respectively. None of the rickshaws were fitted with silencers. Rickshaw drivers were about thrice as likely to be screened as hearing impaired by the SHS questionnaire (RR 2.9, 95% confidence interval 1.6, 5.0), twice as likely to report tinnitus (RR 2.2, 95% confidence interval, 1.1, 3.3) and two and a half times as likely to have difficulty in following telephonic conversations (RR 2.4, 95% confidence interval 1.2, 4.8).

CONCLUSION

There is loss of hearing and tinnitus among rickshaw drivers that could be attributed to their trade. Use of silencers by rickshaw drivers could result in less hearing loss among rickshaw drivers and less noise in the environment for the other 11 million residents in the city.

Safe pre-operative fasting times after milk or clear fluid in children. A preliminary study using real-time ultrasound

Gastric emptying of orange-flavoured glucose (group I), low-fat milk (group II) and breast milk (group III) was evaluated in 45 ASA grade I children of < or = 5 years of age by using real-time ultrasonography and residual gastric volume and pH was then measured. In 15 more children, residual gastric volume and pH was measured after a midnight fast (group IV). Mean (SD) gastric emptying time in group I was 1.53 (0.25) h (range 1.00-1.75), group II 2.32 (0.31) h (range 1.75-2.75) and group III 2.43 (0.27) h (range 2.00-2.75). According to Robert and Shirley's criteria, no children of group I and II were found to be 'at risk' at 2 h and 3 h, respectively, but 13.3% of group III children were labelled as 'at risk' at 3 h. The incidence of 'at risk' children in group IV was 33.3%. It was concluded that 3% fat milk or 17.5% glucose in a volume of 10 ml.kg-1 (maximum volume of 100 ml) can be given in children safely 3 h and 2 h, respectively, before anaesthesia. More real-time studies are required on breast milk to establish guidelines for its potential use as a pre-operative feed 3 h before anaesthesia.

Contractile mechanisms of canine colonic propulsion

We investigated the contractile mechanisms of propulsion in the dog colon. "Propagation index" indicating caudad or orad propagation of contractile states exhibited the strongest correlation with transit during both the fasting and the postprandial states. Other parameters, such as total duration of contractile states and area under contractions, also contributed to transit, but to a lesser degree. All parameters exhibited a stronger correlation with transit during the fasting than during the postprandial state. During the fasting state, the transit rate was faster in the proximal than in the middle colon. The transit rate was linear through the proximal and the middle colon during the postprandial state. In contrast to the phasic contractions and the contractile states, the giant migrating contractions were ultrapropulsive. We conclude that the propagation of contractile states in the colon is a major factor in the slow net distal propulsion of colonic contents. The individual phasic contractions may mainly produce mixing and agitation of colonic contents. Giant migrating contractions rapidly propel colonic contents over long distances.

Subcutaneous infusion of ketamine and morphine for relief of postoperative pain: a double-blind comparative study

Low dose ketamine by subcutaneous infusion (0.1 mg.kg-1.h-1) was compared in a double-blind fashion with a similar infusion of morphine (0.03 mg.kg-1.h-1) for postoperative analgesia in 60 ASA-I adults after major abdominal surgery. Pain was assessed using visual analogue scales and sedation was graded on a four-point rank drowsiness score. Cardiovascular and respiratory parameters were also recorded. Pain relief was better with the ketamine infusion than with morphine infusion (P < 0.001). Both tidal and minute volume parameters improved better with ketamine (P < 0.001); patients were more awake and alert as evidenced by the drowsiness score (P < 0.001). Nine out of 30 patients who received morphine required catheterisation for urinary retention (P < 0.05). The study revealed higher analgesic efficacy of a low dose subcutaneous infusion of ketamine with lesser sedation and fewer side effects.

Intracellular levels and extracellular release of lysosomal enzymes from peripheral blood monocytes in pulmonary tuberculosis patients

The intracellular activity and extracellular release (basal and latex-stimulated) of B-glucuronidase (BG) and N-acetylglucosaminidase (NAG), measured fluorimetrically, were observed to be significantly (P < 0.05) higher in blood monocytes (BM) of untreated pulmonary tuberculosis (TB) patients compared to those of age- and sex-matched controls and Mantoux-positive subjects without any evidence of active disease. After completion of antituberculous therapy, BG and NAG activities declined appreciably (P < 0.05) and their levels became comparable to those in control subjects. The present results suggest the potentiation of the oxygen-independent defense mechanism of BM in pulmonary TB.

Congenital adrenal hyperplasia: experience at intersex clinic, AIIMS

During 1981-88, 63 cases of female pseudohermaphroditism (FPH) were seen at the Intersex clinic at AIIMS, of whom 34 (54%) were diagnosed as due to congenital adrenal hyperplasia (CAH). Though ambiguity was present at birth in most cases, only one child was brought immediately after birth, while 14 presented after one year. Family history of affected siblings and fetal wastage was present in 10. Salt wasting symptoms were present in 13 (38.2%), evidence of early virilization in 10 (29.4%) and generalised hyperpigmentation in 7 (20.6%). Clitoromegaly was present in 30 children with labial fusion in 10 and scrotalisation of labia in 6. The urogenital opening was single in 25 (73.5%). Buccal smear was positive for sex chromatin in 19. Chromosomal pattern showed 46 XX in 33. Dyselectrolytemia was present in 16 children. Bone age was advanced in all. Adrenal hyperplasia could be documented in 3 on CT scan. All the girls were put on hydrocortisone or prednisolone, and fluodrocortisone was given only to children with salt wasting CAH. Children with CAH are being brought to medical attention much too late and investigative and therapeutic facilities are grossly inadequate. There is a need to educate primary care physicians for early case detection and provide minimum diagnostic and therapeutic facilities in regional centres.

Oxidative metabolic status of blood monocytes and alveolar macrophages in the spectrum of human pulmonary tuberculosis

The oxidative metabolic status of blood monocytes (BM) and alveolar macrophages (AM) in patients with active pulmonary tuberculosis (TB) (n = 40) and in successfully treated patients (n = 40) was assessed and compared with that of healthy control subjects (n = 40). Oxygen free radical (OFR) generation, measured by chemiluminescence (CL) and cytochrome c reduction assay and confirmed by using scavengers of different OFR, was suppressed in AM of the pulmonary TB group compared with healthy controls, whereas it was enhanced in BM. Successfully treated patients showed partial recovery of CL and cytochrome c reduction in AM. There was no significant change in BM of patients after having been treated. The overall capacity to generate OFR was markedly suppressed upon in vitro stimulation with latex in both BM and AM of TB patients. The observed suppressed oxidative metabolic activity in BM and AM was further elucidated by studying the molecular mechanism of respiratory burst. The activities of NADPH oxidase and enzymes of the hexose monophosphate (HMP) shunt were significantly (p less than 0.05) decreased in BM and AM of pulmonary TB patients compared with healthy controls. Patients who had been treated showed marked recovery of NADPH oxidase and HMP shunt activity. The present study suggests that tubercle bacilli escape the microbicidal action of macrophages as a result of suppressed OFR generation caused by decreased activity of HMP shunt, leading to decreased levels of NADPH, thereby preventing NADPH oxidase from working at its full capacity.

Hypothalamo-pituitary axis by magnetic resonance imaging in isolated growth hormone deficiency patients born by normal delivery

Magnetic resonance imaging was performed using a 1.5 Tesla magnet in 22 children (14 boys and 8 girls) between 5-20 yr of age with isolated GH deficiency (IGHD), born by normal vaginal delivery without any birth asphyxia or trauma. A total of 22 children (10 boys and 12 girls) without short stature and endocrine disease were evaluated as controls. The IGHD group had a height velocity less than 4 cm/yr and delayed bone age. The peak GH levels were less than 10 micrograms/L (mean, 2.4 micrograms/L). The height of the pituitary gland ranged from 3-7.5 mm in controls. An intact stalk was observed in 21 children with IGHD, with nonvisualization in 1. An apparently thin stalk was seen in 6. The posterior lobe identified by the hyperintensity signal, had a mean diameter of 1.84 mm and was located in a normal position in 21 children. An ectopic posterior pituitary hyperintensity was present in 1 patient. The anterior pituitary was hypoplastic in 17 children, with partial empty sella in 13. A total of 5 children had associated brain anomalies, such as Arnold Chiari malformation, craniovertebral malformation with basilar impression, degenerative plaques around posterior horn of lateral ventricle and parietal area, and infarcts in caudate nucleus and putamen. These findings suggest that IGHD was not related to transection or compression of the stalk.

Can pulse oximetry be used to measure systolic blood pressure?

This study evaluates the use of pulse oximetry to accurately monitor systolic arterial blood pressure in 100 healthy volunteers. Determination of arterial blood pressure using oximetry was made at the disappearance of visual display upon blood pressure cuff inflation, at the reappearance of visual display upon cuff deflation, and by averaging the two. The blood pressures obtained by pulse oximetry were compared with the arterial blood pressures obtained by Korotokoff sounds and noninvasive blood pressure equipment. Good agreement was obtained when the average of oximetry-based systolic blood pressure estimates at the disappearance and reappearance of the waveform were compared with Korotokoff sound pressures and noninvasive equipment pressures. Thus pulse oximetry can be used to measure systolic arterial blood pressure. This technique is specifically important for patients with Takayasu's syndrome (pulseless disease) where conventional techniques often fail to monitor systolic arterial blood pressure.

Colonic motor response to a meal in acute colitis

The symptoms of urgency, diarrhea, and abdominal discomfort are exaggerated after a meal in inflammatory disorders of the colon, such as ulcerative colitis. The possible motor correlates of these symptoms were investigated in a model of acute colitis in six dogs. Each dog was instrumented with seven strain gauge transducers, two on the proximal, three on the middle, and two on the distal colon. After an overnight fast, 4-hour fasted recordings were made from the normal colon and after the colon had been cleansed on the previous day with Colyte (Reed & Carnrick, Piscataway, NJ). A 1300-kcal meal was then fed, and the recordings were continued for another 8 hours. Acute colitis was then induced by the perfusion of 10 mL of 75% acetic acid and confirmed with colonoscopy and biopsy. The fasted and postprandial recordings were repeated during the next 5 days. In the control state, ingestion of the meal increased the total duration per hour of contractile activity in the early (0-2 hours) and late (2-8 hours) postprandial periods in the distal colon. In the proximal and the middle colon, a significant increase in motor activity occurred only during the late postprandial period. Similar effects were observed in the cleansed colon. By contrast, there was no significant increase in motor activity after a meal during colitis in any of the postprandial periods in the cleansed or the uncleansed colon. During colitis, there was a significant increase in the incidence of giant migrating contractions in the fasted state. The ingestion of a meal further increased the frequency of giant migrating contractions in the uncleansed colon from 0.4 +/- 0.1 to 1.3 +/- 0.5 per hour in the late postprandial period. There was no significant increase during the early postprandial period. The increase in the late postprandial frequency of giant migrating contractions was associated with an increase in defecation frequency. It is concluded that the motor response of the colon to a meal is absent in acute colitis. The entry of new ingesta into the colon during the late postprandial period stimulates enteric mechanisms to initiate an excessive number of giant migrating contractions. These giant migrating contractions may be related to increased postprandial abdominal discomfort and increased frequency of defecation.

Biosynthetic growth hormone therapy in children with growth hormone deficiency: experience at AIIMS, New Delhi

A total of 20 previously untreated children with growth hormone deficiency (GHD) were treated for one year with biosynthetic human growth hormone (hGH). The mean chronologic age was 9.43 +/- 3.52 years with a height age of 5.02 years, and bone age 9.43 +/- 3.52 (TW2-RUS) 6.42 years. The mean pretreatment growth velocity was 2.43 +/- 0.90 cm/year. Of these 14 children had complete GHD (peak GH levels less than 5 ng/ml) and 6 had partial GHD. They were treated with recombinant GH in a dose of 0.5 IU/kg/week divided into 6-7 injections per week subcutaneously at night. The mean growth velocity increased to 8.88 +/- 2.10 cm/yr at the end of 6 months and 8.00 +/- 2.21 cm/yr at 12 months. The actual gain ranged from 6-11 cm in a year. There were no local adverse reactions. One child developed vitiligo of the face and another transient hyperglycemia.

Colonic motor activity in acute colitis in conscious dogs

The changes in motor activity of the colon during acute colitis were investigated in six conscious dogs. The motor activity was recorded with seven strain-gauge transducers. Colitis was induced in the entire colon by luminal perfusion of acetic acid. The dogs exhibited urgency and diarrhea with mucus and blood during colitis. The mucosa was diffusely erythematous and friable and there were scattered ulcerations over the mucosal surface. The motor activity of the colon changed in several ways during colitis: (a) the total duration per hour and the mean duration of contractile states decreased significantly; (b) the cycle length of colonic migrating motor complexes was significantly prolonged, and the nonmigrating motor complexes were almost completely absent; and (d) the incidence of giant migrating contractions increased significantly. About half of the giant migrating contractions were followed by defecation. The remaining expelled mucus or gas. Sometimes, a migrating motor complex in the colon was also followed by defecation; this was never observed in the normal state. The motor activity of the colon was still decreased and the cycle length prolonged 21 days after induction of colitis. However, the dogs were asymptomatic at this time and the mucosa looked normal at colonoscopy. The incidence of giant migrating contractions was also normal at this time. It was concluded that the dog is a good model for the study of colitis because of the similarity of symptoms with human ulcerative colitis. The phasic contractions of the colon decreases during colitis but the incidence of giant migrating contractions is increased. The diarrhea in colitis may primarily be due to the large number of giant migrating contractions in the middle and the distal colon.

Role of oxygen free radicals generated by blood monocytes and neutrophils in the pathogenesis of rheumatic fever and rheumatic heart disease

The generation of oxygen free radicals by peripheral blood monocytes and neutrophils of patients with rheumatic fever and rheumatic heart disease has been studied using luminol enhanced chemiluminescence technique. Five groups of patients; acute rheumatic fever, recurrence of rheumatic activity, chronic rheumatic heart disease, acute pharyngitis and normal controls were studied. In all groups except the controls, measurements were made on 0, 15, 90 and 180 days. The chemiluminescence was measured in response to streptococcal membrane antigen, carbohydrate antigen and latex as triggering agents. Chemiluminescent response of monocytes, as well as, neutrophils was significantly higher (P less than 0.01) in acute rheumatic fever and recurrence of rheumatic heart disease as compared to patients with acute pharyngitis and chronic rheumatic heart disease through the study period and with all the triggering agents. A significant decline (P less than 0.001) in chemiluminescence was observed from day 0 to day 180 in the acute rheumatic fever, recurrence of rheumatic heart disease and pharyngitis patients while no such change, was observed in the chronic rheumatic heart disease group. This study raises the possibility that these phagocytic cells, which infiltrate the myocardium, may have a role in the pathogenesis of cardiac disease seen in patients with rheumatic heart disease, through the generation of oxygen free radicals.

Changes in the superoxide anion generating capacity and respiratory burst enzymes of peripheral blood monocytes of monkeys during acute Plasmodium knowlesi infection

The superoxide anion generation profile of peripheral blood monocytes of rhesus monkeys was investigated during the different stages of an acute Plasmodium knowlesi infection. An initial increase in superoxide anion was followed by a significant decline (P less than 0.001), paralleled by a drop in NADPH oxidase activity; there was no alteration in the activity of the hexose monophosphate shunt enzymes. This lowered activity of the NADPH oxidase, with the resulting decreased O2 generation, might be responsible for the failure of the animals to control the parasitaemia; as a result they succumbed to the infection.

Concentration dependent function of superoxide dismutase in oxygen free radicals mediated tissue injury in renal brush border membrane

The dose dependent effect of superoxide dismutase in providing protection against oxygen free radicals mediated tissue damage was investigated. Xanthine-xanthine oxidase system was used to generate oxygen free radicals in vitro and damage renal brush border membrane of mice. At lower concentrations, superoxide dismutase was found to rather aggravate renal brush border membrane damage as shown by significant increase (p less than 0.05) in the malondialdehyde levels and corresponding decrease (p less than .05) in the activities of marker enzymes of renal tissue injury i.e. alkaline phosphatase, gamma-glutamyl transpeptidase and leucine aminopeptidase except maltase whose activity increased correspondingly. At higher doses of superoxide dismutase, significant protection (p less than .05) was observed against tissue damage in a dose dependent manner. On the other hand, catalase and mannitol provided dose dependent protection and their combinations with superoxide dismutase could alleviate the enhanced tissue damage produced by lower doses of superoxide dismutase. The implications of these findings have been discussed.