Responses to dural puncture during institution of combined spinal-epidural analgesia: a comparison of 27 gauge pencil-point and 27 gauge cutting-edge needles.

Pencil-point spinal needles are popular for combined spinal-epidural analgesia because they cause less dural puncture headache than cutting-edge spinal needles. However many parturients move, grimace, vocalise or experience paraesthesia or dysaesthesia during dural puncture when performing 'needle through needle' combined spinal-epidural analgesia. We compared dural puncture responses induced by pencil-point and cutting-edge needles (both 27 gauge). With institutional approval, 115 parturients presenting for elective caesarean section or labour analgesia were audited. After lignocaine infiltration, a Tuohy-type needle was inserted to loss of resistance to saline at a mid-lumbar interspace, and either a 27 gauge cutting-edge or 27 gauge pencil-point needle was inserted 'needle through needle' through the dura. During dural penetration, the occurrence of patient movement, grimacing or vocalisation was noted by a blinded observer, as was the patient's response to the question "Did you feel that?" asked by the anaesthetist. The audit comprised two similar groups of patients (caesarean section, n=30; labour analgesia, n=85). In both groups, grimacing and movement during thecal penetration occurred more frequently with pencil-point needles (P < 0.05 and P < 0.025, respectively). Pooled data analysis revealed that pencil-point and cutting-edge needles induced grimacing and movement in 17 (22%) and 2 (5%), spontaneous vocalisation in 4 (5%) and 1 (3%) and was perceived by 13 (17%) and 3 (8%) parturients (P < 0.025, P=NS, P=NS), respectively. Overall, 34 and 6 objective and subjective patient responses (P < 0.005) occurred when inserting these needles, respectively. Dural puncture by a 27 gauge pencil-point needle inserted 'needle through needle' when instituting combined spinal-epidural analgesia induces more iatrogenic responses than a 27 gauge cutting-edge needle.

Treatment of ruptured ICA during transsphenoidal surgery. Two different endovascular strategies in two cases.

Rupture of the internal carotid artery (ICA) during transsphenoidal surgery is a rare but potentially lethal complication. Direct surgical repair of the ICA may be difficult and time-consuming in an acute setting. Urgent endovascular treatments with vascular plug or stent-graft have been the feasible options to date. We desrcibe two cases of iatrogenic rupture of ICA during transsphenoidal surgery. In the first case we occluded the ICA with a vascular plug at the site of tear where cross circulation was adequate. In the second case we had to preserve the ICA with stent-graft since there was no adequate cross circulation. These two strategies are discussed below.

Loss of resistance to saline reduces responses accompanying spinal needle insertion during institution of 'needle-through-needle' combined spinal-epidural analgesia.

Normal saline or air is used to identify loss of resistance during identification of the epidural space for combined spinal-epidural analgesia. Following epidural needle placement using air for loss of resistance, up to 80% of parturients move, grimace, vocalise or experience paraesthesia or dysaesthesia during subsequent dural puncture by a spinal needle. We compared the effects of saline versus air for loss of resistance on the occurrence of these subjective and objective responses during thecal penetration. With institutional approval, 55 parturients presenting for labour analgesia were studied. After infiltration of lignocaine at an L2-L5 vertebral interspace, a 17 gauge Tuohy epidural needle attached to a 5 ml loss of resistance syringe containing either saline or air was inserted and advanced until loss of resistance was identified by injection of 3 to 5 ml of content. During subsequent 'needle-through-needle' insertion of a 27 gauge pencil-point spinal needle through the meninges, all subjective and objective patient responses were recorded, as well as each patient's reply to the question "Did you feel that?". The two groups (n = 28, n = 27) were comparable. In those given saline and air respectively, 5 (18%) and 12 (44%) parturients responded to and/or acknowledged having perceived dural puncture (P < 0.005). Overall, 7 and 31 (P < 0.0005) subjective and objective responses occurred during dural puncture in those given saline and air, respectively. The study found that use of saline to determine loss of resistance is associated with fewer patient responses at the moment of thecal penetration during 'needle-through-needle' placement of the spinal needle at combined spinal-epidural analgesia.

Cerebral venous sinus thrombosis following accidental dural puncture and epidural blood patch.

We report the case of a woman who developed cerebral venous sinus thrombosis after an attempted epidural. The epidural was complicated by an accidental dural puncture and the ensuing headache was initially treated with an epidural blood patch. Cerebral venous sinus thrombosis is an uncommon condition with varying aetiology and risk factors. We discuss the importance of the differential diagnosis for postpartum headache and explore the relationship between cerebral venous sinus thrombosis and the triad of pregnancy, dural puncture and epidural blood patch.

Paradoxical cerebral arterial gas embolism: Computed tomography findings.

Computed tomography scan findings are described in cerebral arterial gas embolism in two patients with right to left intracardiac shunts by accidental injection of air during intravenous therapy. Although imaging may not be necessary to diagnose the condition, the patient may be referred to CT scan as a case of stroke. Cerebral arterial gas embolism should be considered in the differential diagnosis of stroke, particularly in case of right-to-left shunts. CT findings described are classical and diagnostic of the condition.

Understanding urban vehicular pollution problem vis-a-vis ambient air quality--case study of a megacity (Delhi, India).

Air pollution has become a growing problem in megacities and large urban areas through out the globe, and transportation is recognized as the major source of air pollution in many cities, especially in developing countries. Contribution of automobiles is reported in the range of 40 to 80% of the total air pollution. The challenge facing megacities is how to reduce the adverse environmental impacts and other negative effects of transportation without giving up the benefits of mobility. The dilemma becomes most pressing under conditions of rapid urban growth, which is likely to increase travel demand significantly. The paper is aimed at understanding the problem of vehicular pollution vis-a-vis ambient air quality for a highly traffic affected megacity, Delhi, wherein, the contribution of transport sector was estimated to be as high as 72%. An effort has been made to review and evaluate the benefits (in terms of improved air quality) of the technological interventions/policies adopted for vehicular pollution control in Delhi. It also highlights the outcome of the efforts and suggests further improvements thereon. The importance of public participation and awareness are also discussed. The paper focuses on deriving the benefits of the implementation of management strategies, supported by scientific and technical data/interpretation, so that the people can realize and participate in the government's endeavor for clean city drive in a more effective manner.

Heparin or local thrombolysis in the management of cerebral venous sinus thrombosis?

SUMMARY: Patients with acute cerebral venous sinus thrombosis treated with Heparin or in situ thrombolysis in our department were evaluated in an attempt to rationalize treatment with heparin or thrombolysis. 279 patients with angiographically proven acute cerebral venous sinus thrombosis were included in the study. Patients were classified into mild and severe clinical grade. The study was divided into three phases. Phase I included 27 patients treated with systemic heparin. Phase II included 72 patients, 30 in severe grade and 42 in mild. 26 were thrombolysed with 14 in severe and 12 in mild grade. Phase III included 180 patients treated according to a defined protocol. 133 were in mild grade and 47 in severe. 67 patients were thrombolysed. In the thrombolysed group 27 patients were in mild grade and 40 in severe. 113 patients were treated with systemic heparin. Following acute management all were anticoagulated for six months. The baseline characteristics were found to be same in all three phases. On comparison of outcome in Phase III with Phase 1 the likelihood ratio was found to be statistically significant in favor of Phase III (p<0.0001). The likelihood ratio was found to be statistically significant in mild and severe clinical grade in favor of thrombolysis in Phase III (p 0.039 in mild and p 0.00001 in Severe clinical grade). This ratio was insignificant (p=0.716) for intracranial bleed; however, local puncture site bleeding was found to be significant in the thrombolysed group (0.00005).

Endovascular management of intracranial pial arterio-venous fistulas.

From 1996-2002 we treated 5 consecutive cases of pial fistula. There were 3 patients with a single hole-single channel pial fistula and two patients had a complex pial fistula. Three patients presented with intracerebral hematoma and had a focal neurological deficit. One patient presented with history of seizures and 1 patient had headache. The results of the treatment were analyzed both clinically and angiographically. The follow-up period ranged from 6 months to 6 years. All fistulas were treated with concentrated glue. The glue cast included the distal part of the feeding artery, A-V connection and the proximal part of the vein. Post-embolisation angiography showed complete occlusion of two single-hole fistulas and one complex pial A-V fistula and near total occlusion of one single-hole and one complex pial A-V fistula. Four patients had excellent clinical outcome. One patient with single-hole fistula had a hemorrhagic venous infarct resulting in transient hemiparesis.

Sevoflurane: an ideal agent for adult day-case anesthesia?

Sevoflurane has several properties which make it potentially useful as a day case anaesthetic. Following induction of anaesthesia with propofol, awakening from sevoflurane is faster compared to isoflurane, faster or similar compared to propofol and comparable (in the majority of studies) to desflurane. Subsequent recovery and discharge is generally similar following all agents. Sevoflurane may also be used to induce anaesthesia, which is generally well-received and causes less hypotension and apnoea compared to propofol. When used as a maintenance anaesthetic, the incidence of postoperative nausea and vomiting after sevoflurane is comparable to other inhaled anaesthetics, but this complication appears more common after inhaled inductions. The tolerability and low solubility of sevoflurane facilitate titration of anaesthesia and may reduce the need for opioid analgesia, which in turn may limit the occurrence of nausea and vomiting.