PubMed Health⌕ Search

Biomedical subjects

P K Bithal

Publications and source records attributed to P K Bithal.

At least 19 recordsLinked to original sources

Lidocaine infiltration of the scalp does not completely abolish increased intraocular pressure due to skull pin insertion.

Insertion of skull pins results in haemodynamic perturbations, which can be blunted by local anaesthetic infiltration of the pin sites. No study has assessed the effects on intraocular pressure. General anaesthesia was induced in 71 patients undergoing cervical spine surgery with attachment of Gardner Wells tongs to the skull. Skull pins were attached five minutes after induction following either saline (group I, 35 patients) or lidocaine (group II, 36 patients) infiltration of scalp. Intraocular pressure, mean arterial pressure and heart rate were recorded before (baseline), immediately after, and 60 s following pin insertion and analysed statistically. Insertion of pins increased intraocular pressure in both groups (from 8.4+/-2.7 to 14.2+/-3.0 mmHg in group I, and from 8.8+/-2.3 to 12.7+/-2.7 mmHg in group II, P < 0.001), which persisted even at 60 s but the increase was significantly greater in group I. Insertion of pins significantly increased blood pressure in group I only. We conclude that lidocaine infiltration at the skull pin sites for Gardner Wells tong attachment fails to completely abolish increased intraocular pressure.

Adult↗

Severe bradycardia and hypotension after connecting negative pressure to the subgaleal drain during craniotomy closure.

Negative pressure drainage systems are often used after craniotomy for evacuation of potential bleeding. There are several reports of haemodynamic disturbances with epidural negative pressure drainage, but such reports are very few for subgaleal drains placed over the bone flap. We report a case in which a patient developed severe cardiovascular disturbances after the vacuum drainage was connected to a subgaleal drain after craniotomy for aneurysm clipping. The patient had no significant cardiac history, had an uneventful intra-operative course and yet developed bradycardia and hypotension, which were reproducible and severe enough to require atropine administration. Anaesthetists must be aware of these effects, so that they can anticipate and treat such complications.

Aged↗

Effect of orientation of a standard polyvinyl chloride tracheal tube on success rates during awake flexible fibreoptic intubation.

We conducted a randomised study in 70 patients to assess the effect of orientation of a standard polyvinyl chloride tracheal tube on the ease of railroading the tube during awake fiberoptic orotracheal intubation. Conventional orientation of the tube (with the bevel of the tube directed to the patient's left) was compared with orientation of the tube with the bevel facing posteriorly. The success rate of intubation at the first attempt was higher with the bevel oriented posteriorly (35/35; 100%) than with the conventional orientation (21/35; 60%; p = 0.0001), and the intubating time was shorter (median (range) 7 (5-11) s and 11 (5-60) s, respectively; p = 0.0001). We recommend that the tracheal tube should be aligned in this manner when railroading it over the fibrescope during awake fibreoptic orotracheal intubation.

Adult↗

Atypical presentations in Chiari II malformation.

Myelomeningocele with Chiari II malformation and hydrocephalus is a common association seen in infants with a congenital failure of neurulation. Here we report two cases of such an association presenting with different sets of problems. The first patient presented with severe inspiratory stridor due to bilateral abductor vocal cord paralysis, which was relieved completely within 24 h of definitive surgery. The second patient experienced intraoperative cardiac arrest. Definitive surgery was followed after successful cardiopulmonary resuscitation. The cause of the perioperative sequence of events in both cases is attributed to the associated pathologies of Chiari II malformation.

Arnold-Chiari Malformation↗

Sudden asystole during surgery in the cerebellopontine angle.

We report a case of a 40-year-old lady undergoing surgery for a tumor in the cerebellopontine angle. Intraoperatively, patient had a sudden asystole without prior warning sign of bradycardia. It could have been the severe form of trigeminocardiac reflex. The cardiac rhythm returned spontaneously once the surgical manipulation stopped. The remainder of the operation was uneventful and no complication occurred afterwards. The possible mechanism of the event is discussed.

Adult↗

Effects of stellate ganglion block on cerebral haemodynamics as assessed by transcranial Doppler ultrasonography.

BACKGROUND: Stellate ganglion block (SGB) causes vasodilatation in the skin of the head and neck because of regional sympathetic block. Its effects on cerebral haemodynamics, in health or in disease, are not clear. We evaluated the effects of SGB on ipsilateral middle cerebral artery flow velocity (MCAFV), estimated cerebral perfusion pressure (eCPP), zero flow pressure (ZFP), carbon dioxide reactivity (CO2R) and cerebral autoregulation using transcranial Doppler ultrasonography (TCD). METHODS: Twenty male patients, with pre-existing brachial plexus injury, and undergoing SGB for the treatment of complex regional pain syndrome of the upper limb, were studied. For SGB, 10 ml of plain lidocaine 2% was used and the onset of block was confirmed by presence of ipsilateral Horner's syndrome. The MCAFV, eCPP, ZFP, CO2R, and cerebral autoregulation were assessed before and after SGB using established TCD methods. The changes in these variables were analysed using Wilcoxon's signed rank test. RESULTS: The block caused a significant decrease in MCAFV from median (inter-quartile range) value of 61 (53, 67) to 55 (46, 60) cm s(-1), a significant increase in eCPP from 59 (51, 67) to 70 (60, 78) mm Hg, and a significant decrease in ZFP from 32 (26, 39) to 25 (16, 30) mm Hg. There were no significant changes in CO2R or cerebral autoregulation. CONCLUSION: The increase in eCPP, decrease in ZFP, and no changes in CO2R or cerebral autoregulation suggest that the SGB decreases cerebral vascular tone without affecting the capacity of the vessels to autoregulate. These effects may be of therapeutic advantage in relieving cerebral vasospasm in certain clinical settings.

Adolescent↗

Rupture of aorta and inferior vena cava during lumbar disc surgery.

Major vascular injury during lumbar disc surgery has been recognized as an unusual but well described complication. A potentially fatal outcome can be avoided by a high index of suspicion and an early diagnosis. We present a rare case of aortic and inferior vena caval injury in a 50-year-old female patient undergoing intervertebral disc surgery at lumbar one and two levels. A quick diagnosis and prompt management resulted in a favourable outcome for the patient.

Aorta, Abdominal↗

Intracranial pressure and haemodynamic changes during the tunnelling phase of ventriculoperitoneal shunt insertion.

BACKGROUND AND OBJECTIVE: The tunnelling phase of ventriculoperitoneal shunt insertion is the most painful part but patients are often given inadequate opioid analgesic for fear of post operative delayed recovery and/or respiratory depression. This may result in an increase in intracranial pressure. METHODS: Twenty adults scheduled to undergo ventriculoperitoneal shunt insertion were administered standard anaesthesia. Monitoring included heart rate, electrocardiogram, end-tidal carbon dioxide, invasive blood pressure, and oxygen saturation. Intracranial pressure was monitored by placing the ventricular end of shunt catheter in the dilated lateral ventricle. Five minutes before tunnelling, fentanyl 1 microg kg(-1) was administered. Mean arterial pressure, heart rate and intracranial pressure were recorded during tunnelling and subsequently at 1-min interval for 5 min. Data were analysed using t-test and repeated measured test. RESULTS: Tunnelling caused significant increase in mean arterial pressure (from 81.4 +/- 11.0 to 110.9 +/- 15.3 mmHg, P < 0.05), intracranial pressure (from 21.4 +/- 8.1 to 29.2 +/- 12.5 mmHg, P < 0.05) and heart rate (from 74.4 +/- 13.8 to 94.1 +/- 17.8 beats min(-1), P < 0.05). Whereas, the increase in haemodynamic parameters persisted for 3 min post-tunnelling, elevated intracranial pressure lasted for 2 min. CONCLUSION: Tunnelling significantly increases intracranial pressure and blood pressure despite prior fentanyl administration. This may be deleterious in the presence of intracranial pathology.

Adolescent↗

Anaesthetic management of Osler-Weber-Rendu syndrome with coexisting congenital methaemoglobinaemia.

A 9-year-old cyanosed child suffering from Osler-Weber-Rendu syndrome with bilateral pulmonary arteriovenous malformations (PAVMs) was posted for cerebral angiography under general anaesthesia. Careful preanaesthetic evaluation led to the diagnosis of coexisting congenital methaemoglobinaemia. There is no previous report of Osler-Weber-Rendu syndrome coexisting with congenital methaemoglobinaemia. This report emphasizes that a second contributory cause of cyanosis must be suspected and meticulously looked for if the symptomatology in a patient cannot be explained by a single established diagnosis. Positive-pressure ventilation was associated with reduction in arterial oxygenation despite an increasing inspired oxygen concentration, which returned to preanaesthetic levels only after extubation and resumption of spontaneous respiration.

Anesthesia↗

Comparative incidence of venous air embolism and associated hypotension in adults and children operated for neurosurgery in the sitting position.

BACKGROUND AND OBJECTIVE: Venous air embolism is a constant threat during neurosurgery performed in the sitting position. No large prospective study has compared the incidence of venous air embolism and associated hypotension between adults and children. METHODS: Four hundred and thirty patients (334 adults, 96 children) scheduled to undergo planned posterior fossa surgery in the sitting position (between January 1989 to December 1994) were studied with end-tidal carbon dioxide monitoring. Intraoperatively, a sudden and sustained decrease in end-tidal carbon dioxide tension of >0.7 kPa was presumed to be due to venous air embolism. Management during the episode was on the established guidelines. Hypotension (decrease in systolic arterial pressure of 20% or more from the previous level) was treated with crystalloids and/or a vasopressor. RESULTS: Capnometry detected a 28% incidence rate of air embolism in adults (93/334) and a 22% incidence rate in children (21/96) (P = 0.29). In both groups, the highest incidence rate of embolism took place during muscle handling (44% of adults versus 38% of children, P = 0.8). Embolic episodes were accompanied by hypotension in 37% of adults (34/93) and in 33% of children (7/21) (P = 0.98). To restore arterial pressure to pre-embolic levels, 53% of adults (18/34) and 43% of children (3/7) were administered vasopressors (P = 0.94). There was no intraoperative mortality. The surgical procedure on one adult was abandoned because of persistent hypotension following the embolic episode. CONCLUSION: The incidence of venous air embolism and consequent hypotension is similar in adults and children.

Adult↗

Cardiovascular responses to scalp infiltration with reduced concentration of adrenaline.

A prospective randomized controlled study was carried out in 41 adult neurosurgical patients to find out the hemodynamic effects following scalp infiltration with 0.5% lignocaine with or without adrenaline. The patients were divided randomly into two groups. Group I patients (n=21) received 0.5% lignocaine with adrenaline (1:8,00,000) for scalp infiltration and group II patients (n=20) received 0.5% lignocaine without adrenaline. Continuous monitoring of ECG, heart rate and arterial blood pressure was carried out every minute for 20 minutes following scalp infiltration. Blood loss while raising the scalp flap was assessed by the neurosurgeon who was unaware of the study. No significant hemodynamic disturbances were observed in either group. However, Group I patients had significantly (p=0.001) less bleeding on incision. From this study, we conclude that 0.5% lignocaine with adrenaline (1:8,00,000) does not give rise to any cardiovascular disturbances during and following scalp infiltration. Rather, it minimises blood loss while raising the craniotomy flap.

Adult↗

Airway pressure monitoring as an aid in the diagnosis of air embolism.

We designed a prospective study to compare the validity of airway pressure (AWP) monitoring with that of end-tidal CO2 (ETCO2) monitoring for early detection of air embolism. Subjects included 76 patients of both sexes who underwent neurosurgery in the sitting position. Anesthesia was maintained with O2, N2O, narcotics, pancuronium, and intermittent positive pressure ventilation (IPPV). Continuous monitoring was done of HR, ECG, intraarterial pressure, AWP, and ETCO2. A sudden and sustained decrease in ETCO2 during anesthesia in a hemodynamically stable patient was considered as a sign of air embolism. Concomitant changes in AWP and cardiovascular parameters were also recorded simultaneously. Onset time, stage of surgery, and duration of disturbances were recorded. At the same time, the chest was auscultated for any murmur. Aspiration of air through the CVP catheter was attempted for diagnosis and management of air embolism. ETCO2 monitoring detected 24 episodes (31.5%) of air embolism in 16 patients. We observed 10 episodes (13.1%) of tachycardia in nine patients and nine episodes (11.8%) of hypotension in eight of the 16 patients. Murmur was noted in four patients and air aspiration in six patients. Only six patients of the 16 had an increase in AWP along with the decrease in ETCO2. We conclude that AWP monitoring is neither a sensitive nor reliable indicator of air embolism.

Adolescent↗

Potassium homeostasis during & after cardiopulmonary bypass.

Potassium homeostasis was studied in 30 patients undergoing cardiac surgery by employing cardiopulmonary bypass (CPB) and moderate hypothermia, and using morphine, N2O, relaxant anaesthesia. There was a trend for hypokalemia, and for maintaining a K+ level of 4-4.5 mmol/l, K+ infusion was required during CPB (9.017 mmol/m2 BSA/h). K+ infusion required in the post-operative period was considerably less (1.532 mmol/m2 BSA/h). There was no significant difference in the K+ levels of patients receiving preoperative diuretic therapy, as compared to those not receiving such therapy. Potassium requirement was significantly higher in patients under-going CABG and valvular heart disease, as compared to congenital heart disease. The mean urinary loss of K+ during bypass was found to be 2.95 mmol/m2 BSA/h, which was only 32 per cent of that required to be infused (9.017 mmol/m2 BSA/h). The mean excretion of K+ in the post operative period was significantly higher (4.53 mmol/m2 BSA/h) than K+ required to be infused during this period (1.532 mmol/m2 BSA/h).

Cardiopulmonary Bypass↗

End tidal carbon dioxide monitoring for detection of venous air embolism.

With the aim of defecting the potential hazard of air embolism, end tidal carbon dioxide (ETCO2) was monitored in 238 patients undergoing neurosurgery (in the sitting position), for early detection of venous air embolism (VAE). Fifty six episodes (26.3%) of significant fall in ETCO2 were observed in 41 patients (17.2%). Haemodynamic disturbances occurred in only 26 patients (10.9%) and were always preceded by a fall in ETCO2. Thirteen patients had positive air aspiration and cardiac murmurs were heard in only six. One patient suffered severe hypoxaemia (PaO2 = 55 mm Hg) whereas two had severe haemodynamic disturbances, but could be promptly resuscitated.

Adolescent↗