Implementing nitrous oxide cracking technology in the labour ward to reduce occupational exposure and environmental emissions: a quality improvement study. Anaesthesia 2022;77:1228-1236. [PMID: 36108342 DOI: 10.1111/anae.15838]

Nitrous oxide, a potent greenhouse gas, is a common labour analgesic. One method which may reduce its carbon footprint is to 'crack' the exhaled gas into nitrogen and oxygen using catalytic destruction. In this quality improvement project, based on environmental monitoring and staff feedback, we assessed the impact of nitrous oxide cracking technology in the maternity setting. Mean ambient nitrous oxide levels were recorded during the final 30 minutes of uncomplicated labour in 36 cases and plotted on a run chart. Interventions were implemented in four stages, comprising: stage 1, baseline (12 cases); stage 2, cracking with nitrous oxide delivered and scavenged via a mouthpiece (eight cases); stage 3, cracking with nitrous oxide via a facemask with an air-filled cushion (eight cases); stage 4, cracking with nitrous oxide via a low-profile facemask, and enhanced coaching on the use of the technology (eight cases). The median ambient nitrous oxide levels were 71% lower than baseline in stage 2 and 81% lower in stage 4. Staff feedback was generally positive, though some found the technology to be cumbersome; successful implementation relies on effective staff engagement. Our results indicate that cracking technology can reduce ambient nitrous oxide levels in the obstetric setting, with potential for reductions in environmental impacts and occupational exposure.

Biomarkers of systemic inflammation predict survival with first-line immune checkpoint inhibitors in non-small-cell lung cancer

INTRODUCTION

Pembrolizumab is an established first-line option for patients with advanced non-small-cell lung cancer (NSCLC) expressing programmed death-ligand 1 ≥50%. Durable responses are seen in a subset of patients; however, many derive little clinical benefit. Biomarkers of the systemic inflammatory response predict survival in NSCLC. We evaluated their prognostic significance in patients receiving first-line pembrolizumab for advanced NSCLC.

METHODS

Patients treated with first-line pembrolizumab for advanced NSCLC with programmed death-ligand 1 expression ≥50% at two regional Scottish cancer centres were identified. Pretreatment inflammatory biomarkers (white cell count, neutrophil count, neutrophil/lymphocyte ratio, platelet/lymphocyte ratio, albumin, prognostic nutritional index) were recorded. The relationship between these and progression-free survival (PFS) and overall survival (OS) were examined.

RESULTS

Data were available for 219 patients. On multivariate analysis, albumin and neutrophil count were independently associated with PFS (P < 0.001, P = 0.002, respectively) and OS (both P < 0.001). A simple score combining these biomarkers was explored. The Scottish Inflammatory Prognostic Score (SIPS) assigned 1 point each for albumin <35 g/l and neutrophil count >7.5 × 10⁹/l to give a three-tier categorical score. SIPS predicted PFS [hazard ratio 2.06, 95% confidence interval (CI) 1.68-2.52 (P < 0.001)] and OS [hazard ratio 2.33, 95% CI 1.86-2.92 (P < 0.001)]. It stratified PFS from 2.5 (SIPS2), to 8.7 (SIPS1) to 17.9 months (SIPS0) (P < 0.001) and OS from 5.1 (SIPS2), to 12.4 (SIPS1) to 28.7 months (SIPS0) (P < 0.001). The relative risk of death before 6 months was 2.96 (95% CI 1.98-4.42) in patients with SIPS2 compared with those with SIPS0-1 (P < 0.001).

CONCLUSIONS

SIPS, a simple score combining albumin and neutrophil count, predicts survival in patients with NSCLC receiving first-line pembrolizumab. Unlike many proposed prognostic scores, SIPS uses only routinely collected pretreatment test results and provides a categorical score. It stratifies survival across clinically meaningful time periods that may assist clinicians and patients with treatment decisions. We advocate validation of the prognostic utility of SIPS in this and other immune checkpoint inhibitor treatment settings.

Paediatric granular cell tumour of the larynx: case report of laser resection with frozen section

Granular cell tumours of the larynx are a very rare cause of persistent hoarse or husky voice in children. We report the case of a 13-year-old girl who presented with a three-year history of progressively huskier voice. We discuss the presentation, location and diagnosis of the tumour. In addition, we present a method of surgical treatment of the tumour, involving the hitherto unreported technique of laser excision and frozen section of the lesion.

Fludarabine, adriamycin and dexamethasone (FAD) in newly diagnosed advanced follicular lymphoma: a phase II study by the British National Lymphoma Investigation (BNLI)

The optimal first-line treatment for symptomatic patients with advanced stage follicular lymphoma remains unclear. Fludarabine-based combination regimens have been extensively used in relapsed disease and merit consideration as first-line therapy. We here report the results of a phase II study of FAD (fludarabine, adriamycin, dexamethasone) regimen in 30 patients with advanced stage follicular lymphoma requiring treatment. The response rate was in excess of 90% with 39% achieving a complete remission. The major toxicity was myelosuppression, but only 3% of cycles were associated with grade IV leucopenia. The high response rate has not translated into major improvements in failure-free survival and consideration must be given to alternative treatment modalities to consolidate the high rate of initial responses.

Long-term follow-up of patients treated with radiotherapy alone for early-stage histologically aggressive non-Hodgkin's lymphoma

Historically localised aggressive non-Hodgkin's lymphoma (NHL) has been treated with involved field radiotherapy (RT), chemotherapy, or a combination of both modalities. The current weight of evidence supports a preference for combined modality treatment (CMT). Increased patient age at diagnosis is well recognised as a poor prognostic indicator in NHL, but despite this some perceive CMT as too toxic for use in the elderly. As a result, some older patients continue to be offered RT alone. Here, we present long-term follow-up of 377 adults of all ages treated with RT alone for early-stage diffuse large-cell lymphoma on British National Lymphoma Investigation trials between 1974 and 1997. 10-year cause-specific survival in patients older than 60 years was poor and significantly inferior to that in younger patients (47 and 75% respectively; P<0.001). There is growing evidence that short-course chemotherapy, with or without RT, is superior to RT alone in early-stage aggressive NHL, in elderly as well as in younger patients. Increased age alone should not exclude patients from systemic treatment for early-stage aggressive NHL.

Remission of inflammatory arthropathy in association with anti-CD20 therapy for non-Hodgkin's lymphoma

We describe a case involving a 53-yr-old male with a marginal zone B-cell lymphoma, associated with an IgM paraprotein and a rheumatoid factor-negative inflammatory polyarthropathy, treated with monoclonal anti-CD20 antibody. During the subsequent 12 weeks, evidence of synovitis reduced to a negligible level, despite no significant change in lymphoma bulk or paraprotein level. The relationship between the lymphoma and the arthropathy, and the likely mechanism of remission of the arthropathy, are discussed in the context of the potential value of anti-CD20 therapy in rheumatoid arthritis.

The effects of steroids on vestibular compensation and vestibular nucleus neuronal activity in the guinea pig

Recent studies have suggested that steroids such as dexamethasone and methylprednisolone might be useful in the treatment of vestibular disorders, irrespective of whether inflammatory processes are involved. The aim of this study was to investigate the effects of systemic administration of dexamethasone on vestibular compensation of spontaneous nystagmus (SN) in guinea pig, and the effects of dexamethasone and methylprednisolone on extracellularly recorded spontaneous activity of medial vestibular nucleus (MVN) neurons in brainstem slices in vitro. In the behavioral study, none of the 3 doses of dexamethasone (5, 10, or 40 mg/kg i.p., delivered at 0, 12, 24, and 36 h following a unilateral surgical labyrinthectomy (UL)) resulted in a significant change in the frequency or compensation of SN, relative to the vehicle control group. In the in vitro study, only a minority of MVN neurons showed any response to 1 microM dexamethasone (1 out of 9 neurons), or 10 nM (3 out of 13), or 0.1 microM methylprednisolone (3 out of 7). These results suggest, contrary to previous evidence, that dexamethasone may not accelerate compensation of SN following surgical UL and that dexamethasone and methylprednisolone may have a direct action only on a minority of MVN neurons.

The effects of ginkgolide B (BN52021) on guinea pig vestibular nucleus neurons in vitro: importance of controlling for effects of dimethylsulphoxide (DMSO) vehicles

The present study investigated the effects of the platelet-activating factor (PAF) receptor antagonist, ginkgolide B, on guinea pig medial vestibular nucleus (MVN) neurons in vitro and addressed the potential problem of using dimethylsulphoxide (DMSO) as a solvent. Using DMSO as a solvent, 10(-10), 10(-8) and 10(-4) M ginkgolide B had no effect on extracellularly recorded MVN neurons in brainstem slices in vitro. Using 10(-6) M ginkgolide B, 50% (5/10) of MVN neurons exhibited a decrease in firing rate and 10% (1/10) of neurons responded with an increase in firing rate. While attempting to control for possible DMSO vehicle effects, 40% (4/10) of MVN neurons displayed a decrease in firing rate when ginkgolide B (10(-6) M) was presented before the DMSO control solution. When the DMSO vehicle was presented first, only 10% (1/10) responded similarly. In some cases the DMSO vehicle alone also produced a decrease in MVN neuron firing rate. These results emphasise the importance of using adequate DMSO control conditions in ginkgolide research.

The neuroprotective properties of the Ginkgo biloba leaf: a review of the possible relationship to platelet-activating factor (PAF)

Ginkgo biloba (Ginkgoaceae) is an ancient Chinese tree which has been cultivated and held sacred for its health-promoting properties. There is substantial experimental evidence to support the view that Ginkgo biloba extracts have neuroprotective properties under conditions such as hypoxia/ischemia, seizure activity and peripheral nerve damage. Research on the biochemical effects of Ginkgo biloba extracts is still at a very early stage. One of the components of Ginkgo biloba, ginkgolide B, is a potent platelet-activating factor (PAF) antagonist. Although the terpene fraction of Ginkgo biloba, which contains the ginkgolides, may contribute to the neuroprotective properties of the Ginkgo biloba leaf, it is also likely that the flavonoid fraction, containing free radical scavengers, is important in this respect. Taken together, the evidence suggests that Ginkgo biloba extracts are worthy of further investigation as potential neuroprotectant agents.

Ginkgolide B accelerates vestibular compensation of spontaneous ocular nystagmus in guinea pig following unilateral labyrinthectomy

The aim of this study was to investigate the effects of ginkgolide B on the behavioral recovery process (vestibular compensation) which occurs following surgical removal of the vestibular receptor cells in one labyrinth (unilateral labyrinthectomy, UL). Guinea pigs received a single ip injection of ginkgolide B at the time of the UL (25, 50, or 100 mg/kg) and the effects on the compensation of the UL symptoms, spontaneous ocular nystagmus (SN), yaw head tilt (YHT), and roll head tilt (RHT), were evaluated. The effects of a single vehicle injection or a similar injection of ginkgolide A were used for comparison. Twenty-five mg/kg ginkgolide B significantly increased the rate of SN compensation compared to the vehicle control group (P < 0.02). However, 50 mg/kg ginkgolide B had no significant effect on either SN frequency or the rate of SN compensation. Ginkgolide B (100 mg/kg) significantly altered the rate of SN compensation (P < 0.02); however, SN frequency values were higher at most measurement times. YHT and RHT were not significantly affected by ginkgolide B at any of the doses used. Twenty-five mg/kg ginkgolide A had no significant effect on any of the UL symptoms. These results suggest that, at the optimal dose of 25 mg/kg, a single ip injection of ginkgolide B at the time of the UL can produce an acceleration of SN compensation.

Cutaneous infiltration in T-cell prolymphocytic leukaemia

T-cell prolymphocytic leukaemia (T-PLL) is an aggressive leukaemia accounting for over 30% of all mature T-cell malignancies. We describe the clinical manifestations and histology of cutaneous involvement in a series of 92 patients with T-PLL. Of the 92 patients, 26 (28%) had cutaneous involvement, and in 23 this was present at the time of the diagnosis of the leukaemia. Skin manifestations included a diffuse infiltrated erythema, infiltration localized to the face and ears, nodules and erythroderma. Histology showed a perivascular and periappendageal dermal infiltrate of lymphoid cells with the morphology of prolymphocytes. An early skin biopsy in these patients should help to reveal the underlying diagnosis.