A. M.-H. Ho

Real-time ultrasound-guided paramedian epidural access: evaluation of a novel in-plane technique

BACKGROUNDnCurrent methods of locating the epidural space rely on surface anatomical landmarks and loss-of-resistance (LOR). We are not aware of any data describing real-time ultrasound (US)-guided epidural access in adults.nnnMETHODSnWe evaluated the feasibility of performing real-time US-guided paramedian epidural access with the epidural needle inserted in the plane of the US beam in 15 adults who were undergoing groin or lower limb surgery under an epidural or combined spinal-epidural anaesthesia.nnnRESULTSnThe epidural space was successfully identified in 14 of 15 (93.3%) patients in 1 (1-3) attempt using the technique described. There was a failure to locate the epidural space in one elderly man. In 8 of 15 (53.3%) patients, studied neuraxial changes, that is, anterior displacement of the posterior dura and widening of the posterior epidural space, were seen immediately after entry of the Tuohy needle and expulsion of the pressurized saline from the LOR syringe into the epidural space at the level of needle insertion. Compression of the thecal sac was also seen in two of these patients. There were no inadvertent dural punctures or complications directly related to the technique described. Anaesthesia adequate for surgery developed in all patients after the initial spinal or epidural injection and recovery from the epidural or spinal anaesthesia was also uneventful.nnnCONCLUSIONSnWe have demonstrated the successful use of real-time US guidance in combination with LOR to saline for paramedian epidural access with the epidural needle inserted in the plane of the US beam.

Ultrasound-guided sciatic nerve block: description of a new approach at the subgluteal space

Sciatic nerve block is frequently used for anaesthesia or analgesia during orthopaedic foot surgery and there are several different approaches to the sciatic nerve. This report describes a new approach to the sciatic nerve using ultrasound. Local anesthetic was injected into the subgluteal space under ultrasound guidance which was effective in producing sciatic nerve block in a small series of five patients. The anatomy, sonographic features, technique of identifying the subgluteal space, and potential advantages of this approach to the sciatic nerve are discussed.

Ultrasound-guided lumbar plexus block through the acoustic window of the lumbar ultrasound trident

Lumbar plexus block (LPB) is frequently used in combination with an ipsilateral sacral plexus or sciatic nerve block for lower limb surgery. This is traditionally performed using surface anatomical landmarks, and the site for local anaesthetic injection is confirmed by observing quadriceps muscle contraction to peripheral nerve stimulation. In this report, we describe a technique of ultrasound-guided LPB that was successfully used, in conjunction with a sciatic nerve block, for anaesthesia during emergency lower limb surgery. The anatomy, sonographic features, technique of identifying the lumbar plexus, and the potential benefits of using this approach are discussed.

Understanding immortal time bias in observational cohort studies

MP. High-risk surgery: epidemiology and outcomes. Anesthesia and Analgesia 2011; 112: 891–901. 16. Dripps RD, Lamont A, Eckenhoff JE. The role of anesthesia in surgical mortality. Journal of the American Medical Association 1961; 178: 261–6. 17. Sutton R, Bann S, Brooks M, Sarin S. The Surgical Risk Scale as an improved tool for risk-adjusted analysis in comparative surgical audit. British Journal of Surgery 2002; 89: 763–8. 18. Grocott MP, Pearse RM. Prognostic studies of perioperative risk: robust methodology is needed. British Journal of Anaesthesia 2010; 105: 243–5. 19. Khuri SF, Henderson WG, Daley J, et al. Successful implementation of the Department of Veterans Affairs National Surgical Quality Improvement Program in the private sector: the Patient Safety in Surgery study. Annals of Surgery 2008; 248: 329–36. 20. Barry MJ, Edgman-Levitan S. Shared decision making – pinnacle of patientcentered care. New England Journal of Medicine 2012; 366: 780–1. 21. Pearse RM, Moreno RP, Bauer P, Pelosi P, Metnitz P, Spies C, Vallet B, Vincent JL, Hoeft A, Rhodes A; European Surgical Outcomes Study (EuSOS) group for the Trials groups of the European Society of Intensive Care Medicine and the European Society of Anaesthesiology. Lancet 2012; 380: 1059–65. 22. Pandit JJ. The national strategy for academic anaesthesia. A personal view on its implications for our specialty. British Journal of Anaesthesia 2006; 96: 411–4. 23. Donabedian A. Evaluating the quality of medical care. Milbank Memorial Fund Quarterly 1966; 44: 166–206. 24. Grocott MPW. Improving outcomes after surgery. British Medical Journal 2009; 339: b5173. 25. Mythen M. Fit for surgery? Anesthesia and Analgesia 2011; 112: 1002–4.

Simulation of survivorship bias in observational studies on plasma to red blood cell ratios in massive transfusion for trauma

Observational studies on injured patients requiring massive transfusion have found a survival advantage associated with use of equivalent number of units of fresh frozen plasma (FFP) and packed red blood cells (RBCs) compared with use of FFP based on conventional guidelines. However, a survivorship bias might have favoured the higher use of FFP because patients who died early never had the chance to receive sufficient FFP to match the number of RBC units transfused.

Rotavirus vaccination for Hong Kong children: an economic evaluation from the Hong Kong Government perspective

Aims: To perform an economic analysis of government-funded universal rotavirus vaccination in Hong Kong from the government’s perspective. Methods: A Markov model of costs and effects (disability averted) associated with universal vaccination was compared with no vaccination. In both strategies, newborns were studied until 5 years of age or until they died, using cost, probability and utility data from the literature. The potential cost savings and cost effectiveness of vaccination were calculated and their sensitivities to changes in vaccine and health care costs, presumed decline in vaccine efficacy over time, and the use of discounting and age weights were determined. Results: Depending on assumptions, the new rotavirus vaccines would be cost saving to the Hong Kong Government if they cost less than US

Placing the tip of the endotracheal tube at the carina and passing the endobronchial blocker through the Murphy eye may reduce the risk of blocker retrograde dislodgement during one-lung anaesthesia in small children

40–92 per course. Higher vaccine costs would quickly lead to an incremental cost-effectiveness ratio exceeding that of the gross national product per capita if the mortality rate of rotavirus gastroenteritis remained at zero. Conclusions: Based on 2002 demographic, cost and morbidity data and reasonable uncertainty estimates of these variables, a universal rotavirus vaccination programme paid for by the Hong Kong Government is cost neutral at a per course vaccine cost of US

Accuracy of central venous pressure monitoring during simultaneous continuous infusion through the same catheter

40–92. For a fixed vaccine cost, the potential savings and cost effectiveness of the vaccine increase with higher estimated health care costs and vice versa.

A pharmacokinetic model for factor VIII dosing during active haemorrhage in patients with haemophilia A

We present nine cases of one-lung anaesthesia in small children and infants in which a novel technique was used to reduce the risk of endobronchial blocker retrograde dislodgement. The technique involved threading the stem of the blocker through the Murphy eye of the endotracheal tube (ETT) and deliberately passing the tip of the ETT all the way to the carina. The tip of the ETT blocked any retrograde movement of the blocker.

Renal dysfunction and CABG.

Continuous central pressure monitoring and simultaneous continuous infusion via the same central venous catheter are sometimes necessary. Based on theoretical calculations and experimental measurements, we have determined that pressure monitoring is essentially unaffected if the continuous infusion rate is 50u2003ml.h−1 or less for an adult and a paediatric central catheter. At rates >u200a200u2003ml.h−1, the central venous pressure is exaggerated by up to 4u2003mmHg and 8u2003mmHg for the adult and paediatric catheters, respectively.