Peri-operative considerations for sedation-analgesia during cataract surgery: a narrative review.

Cataract surgery is usually of short duration and is associated with minimal pain when employing topical or regional anaesthesia. Patient education regarding the peri-operative process may help alleviate anxiety and avoid the need for sedation. However, sedation may be required, and we discuss the various options. Many consider that pre-operative fasting is necessary due to the risk of aspiration but fasting may not be required if minimal sedation is administered. If the use of sedatives, hypnotics or analgesics is required, then their associated adverse events should be considered.

The association of pre-operative STOP-BANG scores with postoperative critical care admission.

The STOP-BANG questionnaire screens for obstructive sleep apnoea. We retrospectively analysed the independent association of pre-operative variables with postoperative critical care admission using multivariable logistic regression for patients undergoing elective surgery from January to December 2011. Of 5432 patients, 338 (6.2%) were admitted postoperatively to the critical care unit. In multivariate analysis, the odds ratios (95% CI) for critical care admission were: 2.2 (1.1-4.6), p = 0.037; 3.2 (1.2-8.1), p = 0.017; and 5.1 (1.8-14.9), p = 0.002, for STOP-BANG scores of 4, 5 and ≥ 6, respectively. The odds ratio was also independently increased for: each year of age, 1.015 (1.004-1.026), p = 0.019; asthma, 1.6 (1.1-2.4), p = 0.016; obstructive sleep apnoea, 3.2 (1.9-5.6), p < 0.001; and for ASA physical status 2, 3 and ≥ 4, 2.1 (1.4-3.3), 6.5 (3.9-11.0), 6.3 (2.9-13.8), respectively, p < 0.001 for all.

Cerebellar strokes: a clinical outcome review of 79 cases.

INTRODUCTION: Cerebellar infarcts and haemorrhages are relatively uncommon, accounting for less than 10% of all strokes. The objective of the present study was to quantify and compare the outcomes of patients with cerebellar infarct and those of patients with cerebellar haemorrhage, as well as to identify the risk factors that predict poor outcome in patients with cerebellar stroke. METHODS: We retrospectively reviewed the medical records of consecutive patients admitted to National University Hospital, Singapore, between 2004 and 2006, within one week of cerebellar stroke onset. Baseline data included demographics, concomitant comorbidities, and the presence or absence of brainstem compression and hydrocephalus (on computed tomography or magnetic resonance imaging). The Glasgow Outcome Scale and modified Rankin Score were used to assess outcome at discharge and at six months after discharge. RESULTS: A total of 79 patients with cerebellar stroke were admitted during the study period. Of these 79 patients, 17.7% died and 31.6% had poor outcomes at six months after discharge. Patients with cerebellar haemorrhage were found to be more likely to have poor outcomes as compared to patients with cerebellar infarct, both at discharge (odds ratio [OR] 4.3, 95% confidence interval [CI] 1.3-14.1) and at six months after discharge (OR 5.2, 95% CI 1.6-17.2). When compared to small lesions (< 5 cm(3)), lesions > 20 cm(3) were significantly associated with poorer outcomes and the development of hydrocephalus and brainstem compression. CONCLUSION: Cerebellar strokes are a significant cause of morbidity and mortality. The outcomes of patients with cerebellar haemorrhage are more likely to be worse than those of patients with cerebellar infarct.

Accuracy of ProSeal™ laryngeal mask airway intracuff pressure estimation using finger palpation technique - a prospective, observational study.

The incidence of pharyngolaryngeal adverse events associated with laryngeal mask airways can be reduced by the use of manometry to limit the laryngeal mask airway intracuff pressures. We conducted a prospective, observational study in 80 patients undergoing general anaesthesia with the ProSeal™ laryngeal mask airway to determine the accuracy of a finger palpation technique compared to actual readings obtained from a hand-held manometer by different anaesthesia personnel. The strength of association of estimated versus actual intracuff pressures, R, for nurse anaesthesia assistants, junior anaesthetists and senior anaesthetists were 0.21 (weak), 0.35 (moderate) and 0.78 (strong) respectively. Subgroup analysis showed that anaesthetists with more than three years of experience were more accurate than those with less than three years of experience. The actual versus estimated intracuff pressures were 4±17 vs 19±27 cmH2O (P value <0.001) respectively. In all groups, the palpation technique tended to underestimate the actual intracuff pressure by a mean of 10.3 cmH2O. Palpation accuracy decreased when actual intracuff pressures were >80 cmH2O. These findings suggest that cuff pressure manometry should be recommended as standard of care with the use of laryngeal mask airways.

The Sengstaken-Blakemore tube: uses and abuses.

Due to its complications including oesophageal and gastric ulceration and perforation, the Sengstaken-Blakemore tube is used far less commonly in this new millennium where endoscopic intervention is available. We discuss in a 53-year-old Indian woman an unusual life-saving use of the Sengstaken-Blakemore tube in preventing fatal exsanguination from an aortoesophageal fistula, as well as rare but devastating consequences of the insertion and residence of the Sengstaken-Blakemore tube, including acute airway obstruction and bronchoesophageal fistula.

Effectiveness of 3-in-1 continuous femoral block of differing concentrations compared to patient controlled intravenous morphine for post total knee arthroplasty analgesia and knee rehabilitation.

We assessed the effectiveness of the 3-in-1 continuous femoral block as a form of postoperative pain relief for unilateral total knee arthroplasty (TKA). Sixty patients undergoing elective unilateral TKA under subarachnoid block were randomized into three groups. Postoperative analgesia was provided with a continuous 3-in-1 femoral nerve catheter with 0.15% ropivacaine in group A, a continuous 3-in-1 femoral nerve catheter with 0.2% ropivacaine in group B, or patient controlled intravenous morphine in group C (control group). Groups A and B received patient controlled intravenous morphine pumps for rescue analgesia. Patients in each group were followed for 72 hours postoperatively. Five patients were excluded after randomization. In the remaining 55 patients there was no statistical difference in pain score between the groups. Total morphine use was highest in group C (P < 0.05). No appreciable difference could be found with sensorimotor blockade, morphine usage and satisfaction scores when comparing groups A and B. Femoral catheter dislodgement rate was 7.9%. There was no statistical difference between the groups when comparing the day of first ambulation and the time to discharge from the hospital. Satisfaction scores were higher in group A (P = 0.028) and group B (P = 0.002) compared to group C. We conclude that a continuous 3-in-1 femoral nerve block with ropivacaine 0.15% or 0.2% for elective unilateral TKA has an opioid-sparing effect.

Antiviral effects of amphotericin B methyl ester.

The methyl ester of amphotericin B (AME) is water soluble, retains antifungal activity, and is significantly less toxic in mammals than amphotericin B. In contrast to amphotericin B, which is not water soluble, AME exhibits antiviral effects against vesicular stomatitis virus, herpes simplex virus types 1 and 2, Sindbis virus, and vaccinia virus in a plaque reduction assay. No antiviral effects could be demonstrated against the unenveloped adenovirus type 4 or echovirus type 11. The extent of virus inactivation was found to be dependent upon the AME concentration, contact time, and temperature. No consistent effect of the virus concentration on the probability of plaque-forming unit inactivation could be determined. The antiviral effects of AME were partially antagonized by the presence of serum. Binding of AME to vesicular stomatitis virus was demonstrated by the comigration of drug and virus in linear sucrose gradients. AME represents a new class of antiviral agents with activity at concentrations relevant to therapeutics. Sterol components of the host cell membrane that become incorporated into the viral envelope are postulated as the site of reaction with AME.

Automated analysis of phencyclidine in urine by probability based matching GC/MS.

A novel form of selected ion recording mass spectrometry using a microcomputer-managed mass spectrometer was employed to automatically identify and quantitate phencyclidine (PCP) in cyclohexane extracts of urine by Probability Based Matching. Seventy urine samples from known abusers were assayed for PCP content. The positively identified PCP concentrations ranged from 0.01 to 10.5 mug/ml for 65 samples, 26% of which fell in the 0.35-1.0 mug/ml range and 30% in the 1.0-3.4 mug/ml range. Five specimens had no detectable PCP (less than 10 mug/ml). Cyclohexane extraction efficiency for PCP in urine exceeded 95%. Selected ion monitoring was found to be necessary in order to avoid gas chromatographic interferences produced by co-elution of contaminants at the same retention time as PCP.