Tony Thomson Chandy

Incidence and outcome of acute lung injury and acute respiratory distress syndrome in the surgical intensive care unit

Introduction: To determine the incidence and mortality of acute lung injury (ALI) and acute respiratory distress syndrome (ARDS) in a cohort of patients with risk factors admitted to the Surgical Intensive Care Unit (SICU). Materials and Methods: A prospective observational inception cohort study with no intervention was conducted over 12 months. All patients with at least one known risk factor for ALI/ARDS admitted to the SICU were included in the study. The APACHE II severity of disease classification system scoring was performed within 1 h of admission. The ventilatory parameters and chest radiographs were recorded every 24 h. The P/F ratio, PEEP and Lung Injury Score were calculated each day until the day of discharge from the Intensive Care Unit or for the first 7 days of admission, whichever was shorter. Results: The incidence of ARDS among those who were mechanically ventilated was 11.4%. Sepsis was the most common (34.6%) etiology. Among those with risk factors, the incidence of ARDS was 30% and that of ALI was 32.7%. The mortality in those with ARDS was 41.8%. Those who develop ARDS had higher APACHE II scores, lower pH and higher PaCO2 at admission compared with those who developed ALI or no lung injury. Conclusion: The incidence and mortality of ARDS was similar to other studies. Identifying those with risk factors for ARDS or mortality will enable appropriate interventional measures.

Oral bisoprolol improves surgical field during functional endoscopic sinus surgery

Background: The success of functional endoscopic sinus surgery (FESS) depends on visual clarity of the surgical field, through the endoscope. The objective of this double-blind, randomized, controlled study was to determine if a pre-operative dose of bisoprolol (2.5 mg) would reduce the bleeding during FESS and improve the visualization of the operative field. Materials and Methods: Thirty American Society of Anesthesiologists I or II patients, scheduled for FESS were randomized to receive either a placebo (Group A) or 2.5 mg of bisoprolol (Group B) 90 min prior to the surgery. All the patients received standard anesthesia and monitoring. The aim was to maintain the mean arterial pressure (MAP) of 60-70 mmHg, by titrating dose of isoflurane and fentanyl. The concentration of isoflurane used was recorded every 15 min. At the end of the surgery, the volume of blood loss was measured and the surgeon was asked to grade the operative field as per the Fromme-Boezaart Scale. Result: The blood loss was significantly (P < 0.0001) more in the control group (398.67 ± 228.79 ml) as compared with that in the bisoprolol group (110.67 ± 45.35 ml). The surgical field was graded better in those who received bisoprolol as compared with those in the control group (P − 0.0001). The volume percent of isoflurane and the dose of fentanyl used was significantly lower in those who received bisoprolol. During the operative period, the MAPs were 70.0 ± 2.7 (Group A) and 62.6 ± 3.6 mmHg (Group B) and the heart rate was 99.8 ± 5.0/min (Group A) and 69.2 ± 4.4/min (Group B). These differences were statistically significant ( P − 0.001). Conclusion: This clinical trial has demonstrated that administration of a single pre-operative dose of bisoprolol (2.5 mg) can significantly reduce the blood loss during FESS and improve the visualization of the operating field.

Liver transplantation: Advances and perioperative care

Liver transplantation is one of the treatments for many-life threatening liver diseases. Numerous advances in liver transplant surgery, anaesthesia and perioperative care have allowed for an increasing number of these procedures. The purpose of this review is to consider some of the important advances in perioperative care of liver transplant patients such as pre-operative evaluation, intraoperative monitoring and management and early extubation. A PubMed and EMBASE search of terms “Anaesthesia” and “Liver Transplantation” were performed with filters of articles in “English”, “Adult” and relevant recent publications of randomised control trial, editorial, systemic review and non-systemic review were selected and synthesized according to the authors personal and professional perspective in the field of liver transplantation and anaesthesia. The article outlines strategies in organ preservation, training and transplant database for further research.

Cardiac arrest from tramadol and fentanyl combination

Sir, Tramadol is a centrally acting atypical opioid analgesic commonly used in the treatment of moderate to severe pain. It has a low affinity to μ opioid receptors and also inhibits the reuptake of serotonin and norepinephrine. Fentanyl is a potent, synthetic opioid with a rapid onset of action and strong affinity to μ receptor. Both the drugs are considered to have a high safety profile and used widely in anaesthesia. Fentanyl and tramadol impair presynaptic reuptake of serotonin and in combination with other serotonergic medications can cause serotonin syndrome. We report a case where premedication with the two drugs in therapeutic doses led to serotonin syndrome with severe life-threatening cardiac arrhythmia. A 43-year-old male American Society of Anaesthesiologists physical status1 patient, with radicular pain was scheduled for C5–6 anterior cervical discectomy. He was on gabapentin 150 mg tid and ibuprofen 200 mg bid for pain relief since 1 month. Preanaesthetic evaluation had been insignificant, and and so was the examination prior to shifting into the theatre. After connecting standard monitors and preoxygenation, intravenous (i.v.) fentanyl 50 μg (0.83 μg/kg, in dilution of 1 ml = 50 μg) was administered. Patient was agitating, and pain was thought to be the cause of his agitation. For the fear of developing chest wall, rigidity another agent was considered instead of higher doses of fentanyl. I.v. tramadol 75 mg (1.25 mg/kg, in dilution of 1 ml = 20 mg) was administered slowly over 2–3 min. Immediately a supraventricular rhythm (SVT) with a rate of 180/min and ventricular ectopics were noted on the monitor. It soon deteriorated to ventricular tachycardia (VT) and then into ventricular fibrillation (VF). Cardiopulmonary resuscitation (CPR) was initiated, and airway was secured with endotracheal intubation. Defibrillation with biphasic mode (200 J) was administered thrice during the CPR cycle without sustained sinus rhythm. Injection amiodarone 300 mg bolus was administered after 3rd shock after which sustained sinus rhythm was achieved. After initiating maintenance amiodarone infusion (0.5 mg/kg/h for 24 h) and vasoactive support (noradrenaline and adrenaline infusion at 20 mcg/min) patient was shifted to the intensive care unit (ICU). In the ICU, ventilation was continued for a day with midazolam and morphine for sedation and analgesia. A bedside echocardiogram revealed a good cardiac contractility and output. Induced hypothermia at 34°C was maintained for the day. The next day vasoactive drugs were weaned off, and the patient was awake and successfully extubated. Amiodarone was changed to oral mode of administration and patient was discharged to the ward on 2nd day. The combination of tramadol and fentanyl for premedication is seldom used. The combination has improved tolerance for awake endotracheal intubation[1] and has reduced the incidence of supraventricular arrhythmia in patients undergoing pulmonary resection.[2] Fentanyl associated fatalities have been primarily due to respiratory depression as even low concentrations lead to it.[3] Life-threatening central nervous system (CNS) and cardiac complications are generally found after tramadol ingestion at high doses with unintentional or intentional suicidal attempts. Ahmadi et al., after analysing the cases of tramadol intoxication found mortality rate of 0.97%. Most of the cases have been reported in conjunction with other drugs such as CNS depressants.[4] However, Shadnia et al., reported two fatalities with tramadol intoxication without any co-ingestions.[5] In therapeutic doses, both tramadol and fentanyl have been implicated in serotonin toxicity though tramadol is more notorious for severe toxicity.[6] Serotonin toxicity is marked by the triad of neuromuscular excitation, autonomic stimulation and changes in mental state. Based on the clinical profile we suspected serotonin syndrome to be causative for the complication in our patient. The features of toxicity from drug combination develop rapidly after onset of effective blood levels of the second drug. The autonomic features such as tachycardia and tachypnea are not usually severe.[6] In our patient, the administration of i.v. fentanyl initiated the toxicity features (agitation) which became more pronounced with tramadol dose. However, the cardiac signs erstwhile considered not to be of serious consequence, in our patient caused near fatal arrhythmia. The rhythm quickly transformed from SVT to VT and then to VF [Figure 1]. No role of use of gabapentin preoperatively in this peroperative drug interaction between fentanyl and tramadol could be explained. Figure 1 Electrocardiogram tracing of the rhythm during cardiopulmonary resuscitation To our knowledge and belief, this is the first report of serotonin toxicity with tramadol and fentanyl combination, in therapeutic doses without any other serotonergic medication. The inability to monitor serum drug level has been a limitation, but the absence of any other drug administered prior to fentanyl and tramadol effectively establishes the aetiology. This case report highlights the dangers of combining two drugs with potential of serotonin toxicity and the severity of cardiac complication that can even be near fatal.

Placement of lumbar subarachnoid drain in the sitting position: a technical difficulty.

To JNA Readers: Placement of lumbar drain is a common practice in neurosurgery. There are very few reports that mention difficulty with placement of the catheter in the subarachnoid space,1,2 especially the placement of microcatheters for continuous spinal anesthesia. We would like to report 2 cases where a technical difficulty was encountered, when a lumbar subarachnoid drain had to be placed preoperatively for a transnasal transsphenoidal excision of pituitary adenoma and how this was overcome. Both patients had a body mass index of >30, and hence placement of the lumbar drain was attempted in the sitting position as it improved midline identification as compared with the lateral decubitus position.3 Dural puncture was easily made with a 16-G Tuohy needle (16-G Portex epidural catheter set; Smiths Medical AD Inc., Keene, NH at L2-L3 interspace). Free flow of cerebrospinal fluid (CSF) under high pressure was observed. However, repeated attempts at threading the catheter into the spinal space were unsuccessful. Various alternate maneuvers such as directing the needle laterally and caudally were tried with no success. Observing that the CSF flow was good, we repositioned the patient laterally with the needle in situ. The lateral positioning contributed only to a marginal decrease in CSF flow, however, the catheter placement, with the needle pointing cephalad, was with ease in the lateral decubitus position. We postulate that the technical difficulty observed was probably due to the raised intracranial pressure secondary to an intracranial mass and further compounded by the sitting position. Magnaes had shown that in patients with elevated intracranial pressure, there is a significant rise in CSF pressure while changing from the supine to the sitting position. Similarly increase is also seen when attaining the fully flexed position, that is, chin on chest as compared with the flexed position.5 We presumed that the difficulty encountered was because the catheter had to be threaded against an elevated pressure head in the sitting position. On repositioning to the lateral position, this pressure decreased and hence successful placement of the lumbar drain was achieved. We like to highlight the fact that although a dural puncture may be easier in the sitting position, threading a catheter into the spinal space against the flow of CSF may be difficult due to the increased CSF pressure associated with the intracranial mass and compounded by the sitting position with extreme flexion.

Anaesthetic considerations in a prematurely born infant with congenital hypothyroidism presenting for cataract surgery

Abstract Anaesthetic management of the premature infant is a challenge. This is owing to the immaturity of his or her organ systems and the possible presence of sequelae of premature birth, such as bronchopulmonary dysplasia, apnoea, patent ductus arteriosus and intraventricular haemorrhage. The premature infant is at risk of developing postoperative apnoea, hypothermia and hypoglycaemia until his or her postgestational age is more than 60 weeks. Conditions such as congenital bilateral cataract and congenital hypothyroidism may be associated with other birth defects and syndromes. Recommendations for early cataract surgery may necessitate anaesthetising premature infants with postconceptional ages less than 60 weeks, or those who have had recently diagnosed medical conditions, such as hypothyroidism. We describe the anaesthetic considerations in a, so far, unreported scenario of a premature infant with bilateral congenital cataract and congenital hypothyroidism who presented for cataract surgery.