Kinetic anaesthesia for laser surgery

PURPOSE

Local anaesthetic is widely used in ophthalmic surgery and more recently in vitreoretinal surgery. Akinesia is a useful effect of local anaesthetic blocks, but there are situations where some residual globe movements are of benefit. We looked to see whether reducing the volume of anaesthetic solution used in a block could retain some kinesia while achieving good analgesia.

METHODS

We compared two groups of patients undergoing panretinal photocoagulation (PRP) with an indirect laser. The control group received 5 ml of anaesthetic solution in a single injection by a standard intraconal technique; a second group received a lower volume of solution by the same technique. We recorded the adequacy of anaesthesia and the amount of residual kinesia for the two groups. Differences between groups were analysed using the Student's t-test and chi(2) tests.

RESULTS

The low-volume group received an average of 2.8 ml, compared to 5 ml in the control group. There was no significant difference in the adequacy of analgesia achieved, however 16/18 (89%: 95% confidence intervals (CI)=81.5-96.3%) of the low-volume group had good perioperative kinesia compared to just 3/21 (14%: 95% CI=6.6-21.9%) of the controls (P<0.001).

CONCLUSIONS

We have shown that low-volume intraconal blocks retain some perioperative kinesia without compromising their analgesic effect.

Expanding role of local anaesthesia in vitreoretinal surgery

PURPOSE

Local anaesthesia (LA) is increasingly common in vitreoretinal surgery. However, younger patients often have such surgery under general anaesthesia (GA). We reanalysed the anaesthetic practice for vitreoretinal surgery in our unit over a 19-month period.

METHODS

A total of 1003 patients undergoing vitreoretinal surgery between August 2000 and February 2002 were studied. Type of surgery, patient pain score to anaesthesia and surgery, need for sedation and incidence of complications related to the local anaesthetic were recorded. Comparisons were made between this case series and previous data from our unit.

RESULTS

In total, 920/1003 (91.7%) patients had LA. Total operations comprised 418 vitrectomies, 518 retinopexies with or without vitrectomy and 67 buckling procedures. More patients under the age of 35 years had LA than previously (60.2 vs 35.7%, P<0.001). In 920/920 (100%) of cases, LA was administered via intraconal injection, compared to 164/1221 (13.4%) of procedures previously. Significantly more patients under the age of 35 years required sedation (35.9%) than did older patients (19.2%). Overall, use of sedation was significantly increased since our previous study (20.2 vs 7.8%). Anaesthesia and surgery were well tolerated by patients. There were no cases of orbital haemorrhage or ocular perforation. Complications included bradycardia requiring atropine 1/920 (0.1%) and chemosis 88/920 (9.6%).

CONCLUSIONS

LA is well tolerated and effective even in younger patients. Sedation may well be required in younger patients and for procedures involving scleral buckling. The main indication for GA was patient preference. Despite this, such patients accounted for only 5.2% of the total.

Local anaesthesia for vitreoretinal surgery: an audit of patient and surgical experience

PURPOSE

Local anaesthesia for vitreoretinal surgery is little used as these procedures are deemed to be too long and uncomfortable for patients to tolerate. In this unit anterior intraconal local anaesthesia is used for most routine surgery. We undertook an audit to ensure that surgical standards and patient acceptability were not compromised.

METHODS

A prospective observational audit was performed. Audit data included: Grade of anaesthetist and surgeon; details of anaesthetic and operation; compliance of patient; operating conditions and pain scores. Anaesthesia was provided with a combined peribulbar and intraconal anaesthetic, using bicarbonate buffered lignocaine and bupivacaine 50:50 mixture.

RESULTS

135 (76%) had local anaesthesia alone, 13 (7%) had local anaesthesia with sedation and 29 (16%) had general anaesthesia. 96.4% of patients were compliant and 98.8% of operating conditions were good or excellent. The mean perioperative pain score was 0.1 (range of 0-1), 97% said they would choose local anaesthesia again.

CONCLUSIONS

LA for vitreoretinal surgery is a useful and flexible method of anaesthesia, which has been shown to have excellent patient tolerance.

Local anaesthesia for 1221 vitreoretinal procedures

BACKGROUND

Vitreoretinal (VR) surgery has been increasingly performed under local anaesthesia (LA) in this unit. The results of an audit monitoring this change are presented.

METHODS

Data were collected on 1497 patients including type, volume, and position of the anaesthetic block, type of surgery, complications, and patient reactions.

RESULTS

1221/1479 (82%) patients had LA. They were older than those having general anaesthesia (GA) 63.5 years v 45.9 years; 146 (10.6%) blocks were intracone, 130 (10.6%) peribulbar, and 927 (75.9%) combined. Operations included 436 vitrectomies, 545 retinopexy with or without vitrectomy, and 238 buckling procedures. Some pain was felt by 9.4%, 8.8%, and 19.7% of patients during vitrectomy, retinopexy with or without vitrectomy, and buckling surgery respectively.

CONCLUSION

Local anaesthesia for VR surgery is well tolerated by patients, being effective throughout longer and more stimulating ocular surgery.

Day case management in adjustable suture squint surgery

Day case adjustable suture squint surgery is limited by patient cooperation in the early post-operative period. Nausea is common and may be exacerbated by adjustment. To facilitate early adjustment, in 37 consecutive patients anaesthesia was induced with propofol and the airway maintained with a laryngeal mask. Before and after adjustment patients recorded their level of nausea on a visual analogue scale (1 = no nausea, 10 = vomiting). The mean age of the group was 31.9 years with 20 men and 17 women. Adjustment was performed at a mean time of 4.9 hours after surgery. On the analogue scale of nausea the mean score was 1.54 pre-adjustment and 1.73 post-adjustment. Only 1 patient was given a post-operative anti-emetic. All patients were sufficiently alert to adjust without difficulty and were discharged the same day. The use of a laryngeal mask and induction of anaesthesia with propofol in adjustable suture squint surgery facilitates early adjustment and thus day case management.

Damage to the endothelium in Sjögren's syndrome: lack of correlation with antinuclear antibody titre and presence of antibodies to SSA or SSB autoantigens

Serum levels of von Willebrand factor antigen (as an index of damage to the endothelium) and tissue antinuclear antibodies and antibodies to SSA (Ro) (which have been associated with vasculitis) and SSB (La) autoantigens were measured in patients with Sjögren's syndrome. Although high levels of all indices were recorded, there were no intercorrelations. This provides evidence that although tissue autoantibodies may be useful in confirming a diagnosis, they have no place in the pathological course of the disease and so may be an epiphenomenon.

Plasma and serum von Willebrand factor antigen concentrations in connective tissue disorders

Concentrations of serum and plasma von Willebrand factor antigen were measured in over 200 patients with a variety of connective tissue diseases, and in control samples from over 200 asymptomatic individuals. This comprehensive study found the highest concentrations of von Willebrand factor antigen in patients with vasculitis, Sjögren's syndrome, Felty's syndrome, giant cell arteritis and polyarteritis nodosum. Raised values were also found in rheumatoid arthritis, systemic lupus erythematosus, polymyalgia rheumatica, systemic sclerosis, Raynaud's syndrome, Takayasu's arteritis and Wegener's granulomatosis, but not in oesteoarthritis. It is possible that the difference in von Willebrand factor antigen concentrations in two sub-groups of systemic necrotising arteritis (Wegener's granulomatosis and polyarteritis nodosum) may imply different disease processes. The large numbers involved have allowed us to confirm or question smaller studies of the role of this molecule in connective tissue disease.

Venostasis, subclinical vasculitis and von Willebrand factor antigen

Von Willebrand factor antigen (VW FAg) has been used as a marker for vasculitis and raised levels have been shown to correlate with active disease. The use of VW FAg levels in the diagnosis of vasculitic disorders has been proposed. However, certain cases of vasculitis have normal VW FAg levels and are difficult to diagnose; this is of importance because of the high mortality associated with these disorders. It has been suggested that venostatic stress can be used as a provocative test for stimulating VW FAg release, thereby improving the speed and sensitivity of diagnosis. We tested this hypothesis in a mixed group of 35 patients with vasculitis, systemic lupus erythematosus and rheumatoid arthritis and 16 controls. At baseline, although the levels were not outside the laboratory range, the disease groups had raised VW FAg compared with the simultaneously tested controls. Venostatic stress increased VW FAg activity in all disease groups, control levels also increased and differences between controls and disease groups diminished in significance. Therefore venostatic stress with VW FAg measurement does not produce a more sensitive test for vasculitis. Venostasis should be avoided when measuring VW FAg levels.

The treatment of laryngeal stenosis using the CO2 laser

Conventional open treatment for laryngeal stenosis involves major surgery. Seventeen patients with various pathologies, who needed tracheostomy to relieve their laryngeal stenosis, have been assessed following endoscopic treatment with the CO2 laser. Following an initial direct laryngoscopy, 3 of the patients were considered to be unsuitable for laser treatment. The remaining 14 patients had the stenosed area excised until it was felt that the airway was sufficiently patent to allow closure of the tracheostomy. Eight of the patients were successfully decannulated. The CO2 laser may be used endoscopically to treat certain patients with laryngeal stenosis, who would otherwise require open operation or a permanent tracheostomy.

Relationship between iron deposits and tissue damage in the synovium: an ultrastructural study

A detailed ultrastructural study was made of the synovial iron deposits in cases of haemophilic synovitis (HS), pigmented villonodular synovitis (PVNS), rheumatoid arthritis (RA), osteoarthritis (OA), seronegative inflammatory arthritis (SNA), and in controls, to investigate the relationship between iron deposits and tissue damage. Iron was seen by electron microscopy in about 75% of synovial lining cells in HS and PVNS but only in about 25% of synovial cells from cases of RA and SNA. In cases of OA and in controls iron deposits were scarce. The iron was usually deposited within pleomorphic siderosomes and in HS was most common in type A synovial cells. In contrast, deposits in all other cases were more common in type B cells, which were frequently the predominant cell type, and siderosomes were smaller, more homogeneous, and were more common in deeper synovial tissue. Considerable tissue damage was noted in the vicinity of iron rich siderosomes in synovial A cells from cases of HS, but such deposits in B cells in the synovium from the other cases had relatively little effect. We discuss the possibility that such differences directly reflect the differing functions of type A and B synovial cells, and particularly their relative ability to produce metabolically active oxygen metabolites with tissue destructive potential in the presence of iron.

Laminin and vascular proliferation in rheumatoid arthritis

Laminin is a high molecular weight basement membrane structural glycoprotein. In rheumatoid arthritis and other arthropathies immunoreactive laminin was prominent in synovial blood vessel basement membranes and acted as a marker for them. It codistributed with collagen type IV. Immunohistological reactivity to laminin showed extensive vascular proliferation in rheumatoid arthritis together with basement membrane reduplication, which was confirmed ultrastructurally. Parallel histological studies showed vascular proliferation was predominantly in the subintimal rheumatoid synovium, where it was related to connective tissue proliferation but not to the inflammatory cell infiltrate. Vascular proliferation was also seen in relation to connective tissue changes in biopsies from cases of haemophilic arthritis, osteoarthritis, and meniscal tears. We suggest connective tissue activation is non-specific reaction associated with vascular proliferation. This involves laminin and other structural proteins. It occurs in rheumatoid arthritis and other arthropathies but is distinct from inflammatory cell infiltration.

A model of persistent antigen-induced chronic inflammation in the rat air pouch

Continuing antigen-induced inflammation was established in a subcutaneous air pouch in rats by recurrent local challenge. The animals were sensitized using bovine serum albumin in Freund's complete adjuvant and were challenged 14 days later by injection of the antigen in a solution containing sodium carboxymethylcellulose into the air pouch to produce allergic inflammation. A single antigenic challenge induced acute inflammation with a predominantly polymorph infiltration in the first 48 h. Later samples showed a low-grade mononuclear response which persisted for 4-5 days. Repeated challenge produced chronic inflammation with an accentuated mononuclear response. Connective tissue activation involving fibronectin and collagen was seen as the inflammation progressed, and this was associated with production of ferritin by mononuclear cells. Discontinuation of challenge injections resulted in resolution of the granuloma. We suggest this model can be used to investigate the mechanisms involved in chronic inflammatory diseases with an immunological component and to evaluate the effects of therapeutic intervention upon chronic allergic inflammation.

The nature of iron deposits in haemophilic synovitis. An immunohistochemical, ultrastructural and X-ray microanalytical study

Using a computerized electron-probe X-ray microanalytical technique to measure phosphorus/iron ratios we have defined the iron saturation of ferritin in vitro from prepared ferritin standards of known iron loading. This technique has been applied to the study of 5 haemophilic synovial membranes. At light microscope level the distribution and relationship of iron/ferritin were defined using Perls' reaction and an immunoperoxidase technique respectively. The synovia from all cases contained intra and extra-cellular deposits of Perls' positive material which were granular in nature in the most superficial synovial cells. There were increasing numbers of pheomorphic (1-12 micron diameter ovate bodies in the deeper synovial layers. Immunoperoxidase ferritin staining produced a strongly positive reaction in the granular material but the ovate bodies were negative with the exception of some peripheral staining. X-ray microanalysis showed the granular material to be highly iron saturated ferritin and the ovate bodies to be almost pure iron. We suggest that iron saturated ferritin in the synovial membrane could increase/perpetuate inflammation by promoting lipid peroxidation.

Frequency of occurrence, mode of development, and significance or rice bodies in rheumatoid joints

The incidence of rice bodies (RB) in synovial effusions has been studied in 36 patients with rheumatoid arthritis (RA) and in 12 patients with seronegative inflammatory arthritis (7 cases of Still's disease, 3 of psoriatic arthritis, and 2 of ankylosing spondylitis). In the RA group 50 joints were aspirated before and after saline lavage with a specially designed wide-bore needle. RB were found in 72% overall of the joints studied in this group, 14% on initial simple aspiration and an additional 58% after lavage. In contrast no rice bodies were found in 31 aspirations with lavage by an identical technique in the 12 patients with seronegative synovitis. The RB in RA synovitis occurred both early and late in the course of the disease and were not related to the severity of clinical or radiological changes. However, removal of rice bodies was accompanied by clinical improvement and reduction of synovitis. Macroscopically RB varied in shape and size, some being so large as to preclude effective removal by needles of the gauge customarily employed for joint aspirations. Microscopically the majority of RB were composed of coarsely reticular material reacting immunologically with antifibrinogen and antifibronectin and containing mononuclear cells. Some showed vacuolation suggestive of fibrinolysis, but many showed organisation like that seen in established connective tissues, with the formation of mature collagen, reticulin, and elastin. These findings are discussed in relation to the origin, development, and significance of rice bodies in rheumatoid synovitis.

Significance of fibronectin in rheumatoid arthritis and osteoarthrosis

Fibronectin is a glycoprotein secreted by connective tissue cells into their environment and into the blood. Plasma fibronectin has been isolated and used to prepare an antiserum. This has been shown to be specific for fibronectin and unreactive with fibrin(ogen) and collagen, to which fibronectin binds in vitro. The antiserum has been used to examine the distribution of this protein in the synovium in health, in rheumatoid arthritis, and in osteoarthrosis, and to estimate levels in plasma and synovial fluid. The results suggest that fibronectin is synthesised by synovial cells, and the synovial fluid level of fibronectin was found to be about twice the plasma level in rheumatoid arthritis. In long-standing arthritis fibronectin was also found to be codistributed with (presumably by adsorption upon) fibrin and immature collagen in intra-articular structures but was no longer demonstrable in areas where mature collagen had been formed in areas undergoing fibrosis. The possible significance of local fibronectin production within joints in relation to its possible effect on the resolution or continuance of arthritis is discussed.