Pneumomediastinum, subcutaneous emphysema and pneumorrhachis following cocaine insufflation: a case report

A case report on a 36-year-old male patient presenting to the emergency department (ED) with chest tightness, nasal sounding voice and subcutaneous emphysema 72 hours after the nasal insufflation of approximately 0.5g of cocaine. A plain radiograph of the chest demonstrated an extensive pneumomediastinum with subcutaneous emphysema extending into his neck. A computerised tomography (CT) scan confirmed the above findings, along with a pneumorrhachis of the thoracic spine. He was admitted locally for further investigation and observation. Cocaine is the second most used illicit drug in the UK. The associated complications of cocaine can vary from acute coronary syndrome to acute psychosis. Pulmonological trauma secondary to cocaine misuse is commonly associated with inhalation of cocaine; we present this rare case of subcutaneous emphysema, pneumomediastinum and pneumorrhachis secondary to nasal insufflation. It is believed that deep nasal insufflation of cocaine is followed by forceful Valsalva manoeuvre, which allows for the rapid absorption of the drug and increases the euphoric effect. This forceful inhalation can lead to barotrauma and leakage of air into the posterior mediastinum.

Multidimensional Treatment Foster Care for Adolescents in English care: randomised trial and observational cohort evaluation

BACKGROUND

Children in care often have poor outcomes. There is a lack of evaluative research into intervention options.

AIMS

To examine the efficacy of Multidimensional Treatment Foster Care for Adolescents (MTFC-A) compared with usual care for young people at risk in foster care in England.

METHOD

A two-arm single (assessor) blinded randomised controlled trial (RCT) embedded within an observational quasi-experimental case-control study involving 219 young people aged 11-16 years (trial registration: ISRCTN 68038570). The primary outcome was the Child Global Assessment Scale (CGAS). Secondary outcomes were ratings of educational attendance, achievement and rate of offending.

RESULTS

The MTFC-A group showed a non-significant improvement in CGAS outcome in both the randomised cohort (n = 34, adjusted mean difference 1.3, 95% CI -7.1 to 9.7, P = 0.75) and in the trimmed observational cohort (n = 185, adjusted mean difference 0.95, 95% CI -2.38 to 4.29, P = 0.57). No significant effects were seen in secondary outcomes. There was a possible differential effect of the intervention according to antisocial behaviour.

CONCLUSIONS

There was no evidence that the use of MTFC-A resulted in better outcomes than usual care. The intervention may be more beneficial for young people with antisocial behaviour but less beneficial than usual treatment for those without.

Olfaction by melanophores: what does it mean?

Hypotheses on general olfaction can be divided into two broad groups: those that predict the existence of olfactory-specific olfactory receptor proteins and those that do not. Recently, much attention has been paid to the discovery of an odorant-stimulated adenylate cyclase in purified olfactory cilia. This finding has, for the most part, been accepted as evidence that the former hypotheses are correct. Here we report that frog melanophores, which are nonolfactory in nature, disperse their melanosomes in response to the same types and concentrations of odorants used in the investigations of olfactory cilia and that pigment dispersion is accompanied by rises in intracellular cAMP levels. The effects show that the existence of a cAMP-based second messenger system in olfactory cilia is not in itself proof of the existence of olfactory-specific olfactory receptor proteins. Also they explain the basis of Ottoson's pioneering work of 30 years ago on the electrical responses of frog olfactory epithelium to stimulation with alcohols. The results suggest that there could be two mechanisms that are important for the detection of odorants: one based on specific receptors, the other nonspecific, but both working through activation of cAMP.

The enkephalinase inhibitor, GB 52, does not affect nociceptive flexion reflexes nor pain sensation in humans

The effects of intravenous administration of 2.5 mg/kg of GB 52, a highly potent derivative of the enkephalinase inhibitor, thiorphan, were studied on the threshold of both the nociceptive reflex (Tr) and sensation of pain (Tp) as well as on the thresholds of both recruitment of the maximal nociceptive reflex response (Tmr) and tolerable pain (Tip), elicited by electrical stimulation of the sural nerve in normal and relaxed volunteers. It was found that neither the nociceptive motor responses (Tr and Tmr) nor the subjective reports of pain (Tp and Tip), were significantly affected by GB 52. It is concluded that, in the experimental conditions used, the transmission of nociceptive messages at the spinal level is not tonically modulated by any enkephalinergic system.

Psychophysical and electrophysiological approaches to the pain-relieving effects of heterotopic nociceptive stimuli

The nociceptive flexion reflex (RIII reflex) and the concurrent subjective pain score elicited by right sural nerve stimulation at random intensities were studied in 10 healthy volunteers. A close relationship was found between the recruitment curves of the reflex and the pain score as a function of stimulus intensity. As a consequence, the threshold of the RIII reflex (Tr) and of pain sensation (Tp) were found to be almost identical (mean: 9.8 and 11.3 mA, respectively). Similarly, the threshold for obtaining a maximal reflex response (Tmr) was found to be very close to that for intolerable pain (Tip): 33.5 and 35.1 mA, respectively. These four parameters were studied before and during the immersion of the left hand into a heated thermoregulated waterbath at various temperatures (from 40 to 47.5 degrees C). While nonnociceptive temperatures (40 to 44 degrees C) were without effect, higher conditioning temperatures induced an increase in the four thresholds. In addition, a highly significant linear relationship was observed between the increase in these thresholds and the intensity of the conditioning stimulus in the 44 to 47.5 degrees C range. These four parameters were also studied before and during three other nociceptive conditioning stimuli: immersion of the left hand into a 6 degrees C waterbath, 10 watts muscular exercise of the left hand performed under ischaemia and a painful (5.5 kg/cm2) pinch applied on the nasal septum. These three conditioning situations induced a very significant increase of the four thresholds considered in this study with the greatest being observed during nociceptive cold applied to the left hand. During all the conditioning situations, variations in Tr and Tp as well as in Tmr and Tip were found to be linearly related. This indicates a close relationship between the effects of the conditioning nociceptive stimuli on the reflex and the related pain sensation. These results suggest that the modulation of pain by heterotopic nociceptive stimuli can be explained at least in part by a depression in the transmission of nociceptive messages at the spinal level. They are discussed with reference to the counterirritation phenomena and common features with 'diffuse noxious inhibitory controls' (DNIC) are underlined.

Can vibration-induced illusions be used as a muscle perception test for normal and cerebral-palsied children?

Since poor control of muscle contractions in cerebral palsy may be due partly to defective processing of data originating from muscle, the need arose for a test as uncontaminated as possible by other afferent effects. For 18 normal children, vibration of the brachial biceps tendon always gave the illusion of elbow extension; when the triceps was vibrated the opposite illusion occurred. For 22 cerebral-palsied children the vibration test was successful for 26 elbows and failed for 18. These failures might provide a future explanation for certain therapeutic failures.

Effect of a synthetic enkephalin analogue on spinal nociceptive messages in humans

The effects of a single dose (1.0 mg. i.v.) of a synthetic methionine enkephalin, FK 33-824 (FK) on spinal nociceptive pathways were studied in 3 normal subjects and in 3 paraplegic patients. In normal patients, FK 33-824 produced an increased threshold of a nociceptive flexor reflex of the lower limb as well as a decrease in the slope of the recruitment curve of this reflex as a function of stimulus intensity. The inhibition of a monosynaptic reflex induced by conditioning noxious cutaneous stimulation was also reduced by FK 33-824. In patients, administration of FK 33-824 resulted in marked depression of supraliminal nociceptive reflexes, showing a direct spinal effect of this opioid. In all subjects, FK 33-824 also produced severe side effects. All these effects were naloxone-reversible (0.03 mg/kg. i.v.). The clinical implications of these data are discussed.

Depressive effect of coughing on spinal monosynaptic reflexes in conscious man

1. The relationship between coughing and spinal monosynaptic reflexes (SMR) in extensors and flexors was investigated in eight healthy subjects by using the Hoffmann technique. Coughing exerted major depression (81% in extensor and 83% in flexor SMR). This depressant effect began simultaneously with the first cough and lasted through the coughing phase. Complete recovery to initial values occurred an average of 40 s thereafter. 2. In comparison, mental tasks induced only a slight decrease in SMR amplitude. In contrast, the Mueller and Valsalva manoeuvres induced facilitation. 3. During coughing, large variations in extensor amplitudes were observed that were coupled with the ventilatory cycle. Slight facilitation was observed during inspiration, but expiration induced pronounced depression, occurring 0.20 s after the beginning of the expiratory period. Experiments performed during baseline breathing failed to show any change throughout inspiratory or expiratory phases. 4. Chemical stimulation of irritant receptors (inhalation of citric acid) produced no specific modification of extensor responses compared with the effect of placebo inhalation (distilled water). 5. These data suggest that coughing exerts a major depressant effect on motor activity via a loop that possibly includes cardiopulmonary receptors and inhibitory supraspinal descending pathways.

Depressive effect of high frequency peripheral conditioning stimulation upon the nociceptive component of the human blink reflex. Lack of naloxone effect

High frequency (100 Hz) low intensity (2 mA) peripheral conditioning stimulation of either segmental or heterosegmental cutaneous nerves induced non-naloxone-reversible depression of the nociceptive component of the human blink reflex. Electrophysiological studies suggest that this depression is due to a local synaptic inhibitory mechanism involving convergence interactions between several cutaneous afferents onto a same internuncial pool in the trigemino-facial path.

Electrophysiological evidence for a possible serotonergic involvement in some endogenous opiate activity in humans

The effects of indalpine (a selective 5-HT uptake inhibitor) on the threshold of lower limb nociceptive flexion reflexes were studied (double blind) in humans. After 3 days' administration, indalpine was found to exert a significant naloxone-reversible depression (threshold increased) of the nociceptive reflexes (naloxone and saline were tested double blind). In contrast, no change was found during treatment with placebo. The functional and therapeutic implications of these results are discussed.

Morphine reinforces post-discharge inhibition of alpha-motoneurons in man

Morphine chlorhydrate (0.25 mg/kg)produced a significant and constant reinforcement of post-discharge inhibition of alpha-motoneurons in both normal and paraplegic humans. This effect was reversed by naloxone hydrochloride (0.02 mg/kg). These data do not allow to differentiate the effects of morphine on recurrent inhibition and on A.H.P.

Selective blockade of dopamine-induced vasodilation by ergonovine maleate in the vasculatures of dogs and rabbits

In urethane anesthetized rabbits, ergonovine maleate significantly attenuated dopamine-induced systemic hypotension. Initial pressor responses to dopamine were significantly prolonged and potentiated by ergonovine. Mesenteric vasodilation elicited by dopamine in dogs was competitively inhibited by ergonovine at doses of 0.09 and 0.18 mg/kg, i.a. Failure of ergonovine to inhibit vasodilatory responses to acetylcholine or isoproterenol suggested selective blockade. These results confirm existing evidence that ergonovine selectively antagonizes peripheral dopaminergic receptors subserving vasodilation.