Local anaesthetic adjuncts for peripheral regional anaesthesia: a narrative review

Moderate-to-severe postoperative pain persists for longer than the duration of single-shot peripheral nerve blocks and hence continues to be a problem even with the routine use of regional anaesthesia techniques. The administration of local anaesthetic adjuncts, defined as the concomitant intravenous or perineural injection of one or more pharmacological agents, is an attractive and technically simple strategy to potentially extend the benefits of peripheral nerve blockade beyond the conventional maximum of 8–14 hours. Historical local anaesthetic adjuncts include perineural adrenaline that has been demonstrated to increase the mean duration of analgesia by as little as just over 1 hour. Of the novel local anaesthetic adjuncts, dexmedetomidine and dexamethasone have best demonstrated the capacity to considerably improve the duration of blocks. Perineural dexmedetomidine and dexamethasone increase the mean duration of analgesia by up to 6 hour and 8 hour, respectively, when combined with long-acting local anaesthetics. The evidence for the safety of these local anaesthetic adjuncts continues to accumulate, although the findings of a neurotoxic effect with perineural dexmedetomidine during in-vitro studies are conflicting. Neither perineural dexmedetomidine nor dexamethasone fulfils all the criteria of the ideal local anaesthetic adjunct. Dexmedetomidine is limited by side-effects such as bradycardia, hypotension and sedation, and dexamethasone slightly increases glycaemia. In view of the concerns related to localised nerve and muscle injury and the lack of consistent evidence for the superiority of the perineural vs. systemic route of administration, we recommend the off-label use of systemic dexamethasone as a local anaesthetic adjunct in a dose of 0.1–0.2 mg.kg⁻¹ for all patients undergoing surgery associated with significant postoperative pain.     

Quantifying infection risks in incompatible living donor kidney transplant recipients

Desensitization has enabled incompatible living donor kidney transplantation (ILDKT) across HLA/ABO barriers, but added immunomodulation might put patients at increased risk of infections. We studied 475 recipients from our center from 2010 to 2015, categorized by desensitization intensity: none/compatible (n = 260), low (0-4 plasmaphereses, n = 47), moderate (5-9, n = 74), and high (≥10, n = 94). The 1-year cumulative incidence of infection was 50.1%, 49.8%, 66.0%, and 73.5% for recipients who received none, low, moderate, and high-intensity desensitization (P < .001). The most common infections were UTI (33.5% of ILDKT vs. 21.5% compatible), opportunistic (21.9% vs. 10.8%), and bloodstream (19.1% vs. 5.4%) (P < .001). In weighted models, a trend toward increased risk was seen in low (wIRR = _0.771.40_2.56,P = .3) and moderately (wIRR = _0.881.35_2.06,P = .2) desensitized recipients, with a statistically significant 2.22-fold (wIRR = _1.332.22_3.72,P = .002) increased risk in highly desensitized recipients. Recipients with ≥4 infections were at higher risk of prolonged hospitalization (wIRR = _2.623.57_4.88, P < .001) and death-censored graft loss (wHR = _1.154.01_13.95,P = .03). Post–KT infections are more common in desensitized ILDKT recipients. A subset of highly desensitized patients is at ultra-high risk for infections. Strategies should be designed to protect patients from the morbidity of recurrent infections, and to extend the survival benefit of ILDKT across the spectrum of recipients.     

RENAL TRANSPLANTATION – AN EARLY EXPERIENCE

Renal transplant (RT) is now a therapy of choice for end stage renal disease (ESRD). The Nephrology Unit, Asvini started functioning in Dec 90 and to date 1298 sittings of hemodialysis have been given to 45 patients. Of these, 35 were in ESRD and 11 patients underwent renal transplantation at this hospital during the period Jan 91 – Dec 93. One patient expired after 18 months of transplantation due to infection. Early experience in screening patients for RT, use of immunosuppression, management of rejection episodes and protocol are presented with special emphasis on its relevance to the Armed Forces.KEY WORDS: Transplantation, Renal Failure, Immunosuppression, Rejection     

Typhoid fever in a 7 month old infant

The clinical profile of typhoid fever in an infant is variable and non-specific. A rare case of typhoid fever in a 7 month old infant is reported. The child presented with only a day's history of fever and loose motions which resulted in severe dehydration, acute tubular necrosis and death. The diagnosis of typhoid fever was made only on post-mortem study. The problem in diagnosing typhoid fever in a young infant is highlighted with a brief literature review on the subject.     

Bench surgery with autotransplantation for bilateral synchronous Wilms' tumor: a report of three cases

The surgical management of bilateral synchronous nephroblastoma remains controversial. The authors describe three cases treated using ex vivo tumor dissection followed by autotransplantation in an attempt to preserve functioning renal tissue. Two children are alive and tumor free with adequate renal function at 30 months and 3 years, respectively. One died from tumor recurrence with metastases 9 months after surgery. This technique is an acceptable alternative to bilateral nephrectomy followed by transplantation.     

Priming of neutrophil [Ca2+]i signaling and oxidative burst by human fracture fluids

BACKGROUND: Patients with major fracture/soft-tissue injuries are at risk for adult respiratory distress syndrome after secondary infection. Fracture fluids (FF) are rich in neutrophil (PMN) -specific chemokines such as interleukin-8. PMN respond to both interleukin-8 and bacterial stimuli with calcium ([Ca2+]i) fluxes, which can initiate respiratory burst (RB). We hypothesize that small amounts of FF entering the circulation could exaggerate PMN [Ca2+]i and RB responses, potentially increasing the risk of adult respiratory distress syndrome. METHODS: FF were obtained from 10 patients at open fixation of the femur 2 to 5 days postinjury. Volunteer PMN were isolated and loaded with fura dye. PMN were preincubated either in 30% autologous plasma (AP)/70% buffer, or in 5% FF/25% AP/70% buffer. Cells were resuspended in buffer with 1,2,3-dihydrorhodamine and stimulated with low-dose n-formyl-methionyl-leucyl-phenylalanine (fMLP). [Ca2+]i was assayed by fura fluorescence at 505 nm after excitation at 340/380 nm. RB was assessed by 1,2,3-dihydrorhodamine fluorescence at 530 nm after 488 nm excitation. RESULTS: PMN basal [Ca2+]i was higher after FF incubation than AP incubation (94+/-12 vs. 61+/-9 nmol/L, p = 0.0002). Peak [Ca2+]i response to fMLP was 475+/-47 nmol/L after FF but only 356+/-22 nmol/L after AP (p = 0.01). Two hundred seconds after fMLP, [Ca2+]i remained higher after FF (172+/-17 vs. 145+/-9 nmol/L, p = 0.04). Basal RB was slightly higher after FF than AP (13.4+/-0.3 vs. 11.3+/-0.3 units, p = 0.051) as was the maximal rate of extracellular oxidant release (1.10+/-0.17 vs. 0.76+/-0.16 units/s, p = 0.004) and total oxidant production (42.5+/-0.8 vs. 31.7+/-0.8 units, p = 0.006). CONCLUSION: Small amounts of FF in plasma can exaggerate PMN [Ca2+]i flux and RB responses to subsequent bacterial stimuli. These findings are consistent with the hypothesis that release of FF into the circulation primes PMN and, thus, may predispose to adult respiratory distress syndrome. Such PMN priming events might have important implications for both the operative and medical management of patients with major fractures.     

Profile of patients presenting for cataract surgery in the UK: national data collection

AIMS/METHODS: A national data collection exercise was carried out in more than 100 hospital eye service units within the UK to provide clinical and administrative information on patients undergoing cataract surgery. This included patient clinical data such as visual acuity at the time of wait listing and at the time of admission for surgery, presence of other eye disorders, other serious medical disorders, and data on waiting time and type of admission. RESULTS: The profiles of the 18 454 patients aged 50 years or older are reported. Findings of particular note were as follows. At the time of wait listing for cataract surgery 31% had visual acuity of 6/12 or better, 54% had visual acuity between 6/18 and 6/60, and 15% had less than 6/60 vision. Considering those who had visual acuity of 6/12 or better at the time of wait listing, by the time of admission for surgery, the vision deteriorated to 6/18-6/60 in 33% and in a further 3% the vision deteriorated to below 6/60. In patients with moderately poor visual acuity (<6/12-6/60) at the time of wait listing, 13% had less than 6/60 vision by the time of admission for surgery. CONCLUSION: This type of data collection and reporting exercise provides new material that can be used in the planning and provision of cataract surgery services in the UK.     

Capillaria hepatica parasitism

Capillaria hepatica is rarely encountered in humans, with fewer than 30 documented cases. The clinico-pathological features of capillaria hepatica infection, diagnosed on liver biopsy of a 6-year-old child are discussed. Pathologically, it is characterised by prominent granulomatous lesions in the liver surrounding the eggs, which on cursory examination may be confused withSchistosoma mansoni.