Hyperbaric oxygen treatment for infants: retrospective analysis of 54 patients treated in two tertiary care centres

Introduction

We aimed to analyse the outcomes of hyperbaric oxygen treatment (HBOT) and describe difficulties encountered in infants, a rare patient population in this therapeutic intervention, with limited scientific reports.

Methods

This was a retrospective analysis of patients 12 months old or younger who underwent HBOT in two different institutions. Demographic data, clinical presentation, HBOT indication, chamber type, oxygen delivery method, total number of treatments, outcome and complications were extracted from clinical records.

Results

There were 54 infants in our study. The patients' median age was 3.5 (range 0-12) months. The major HBOT indication was acute carbon monoxide intoxication (n = 32). A total of 275 HBOT treatments were administered, mostly performed in multiplace chambers (n = 196, 71%). Only one patient (2%) required mechanical ventilation. Acute signs were fully resolved in the most patients (n = 40, 74%). No complications related to HBOT were reported.

Conclusions

This study suggests that HBOT may be a safe and effective treatment for infants. Paediatricians should consider HBOT when indicated in infants even for the preterm age group.

Hyperbaric oxygen treatment in delayed post-hypoxic encephalopathy following inhalation of liquefied petroleum gas: a case report

Delayed post-hypoxic encephalopathy can occur after an episode of anoxia or hypoxia. Symptoms include apathy, confusion, and neurological deficits. We describe a 47-year-old male patient who inhaled gas from a kitchen stove liquid petroleum gas cylinder. He was diagnosed with hypoxic ischaemic encephalopathy 12 hours after his emergency department admission. He received six sessions of hyperbaric oxygen treatment (HBOT) and was discharged in a healthy state after six days. Fifteen days later, he experienced weakness, loss of appetite, forgetfulness, depression, balance problems, and inability to perform self-care. One week later, he developed urinary and fecal incontinence and was diagnosed with post-hypoxic encephalopathy. After 45 days from the onset of symptoms, he was referred to the Underwater and Hyperbaric Medicine Department for HBOT. The patient exhibited poor self-care and slow speech rate, as well as ataxic gait and dysdiadochokinesia. Hyperbaric oxygen was administered for twenty-four sessions, which significantly improved the patient's neurological status with only hypoesthesia in the left hand remaining at the end of treatment. Hyperbaric oxygen has been reported as successful in treating some cases of delayed neurological sequelae following CO intoxication. It is possible that HBO therapy may also be effective in delayed post-hypoxic encephalopathy from other causes. This may be achieved through mechanisms such as transfer of functional mitochondria to the injury site, remyelination of damaged neurons, angiogenesis and neurogenesis, production of anti-inflammatory cytokines, and balancing of inflammatory and anti-inflammatory cytokines.

Influence of atmospheric pressure changes on dentin bond strength of conventional, bulk-fill and single-shade resin composites

INTRODUCTION

The purpose of this study was to investigate the dentin bond strength of composite resins in response to environmental pressure changes.

METHODS

Ninety extracted human molar teeth were used. A mould (3 mm x 4 mm) was adapted on dentin, resin composites (conventional [n = 30] and single-shade composites [Ohmnicroma] [n = 30]) were filled in two increments of 2 mm. The bulk-fill composites (n = 30) were filled with one 4 mm increment. The specimens were stored for 30 days in artificial saliva. The specimens were exposed to hyperbaric pressure (283.6 kPa; 2.8 atmospheres absolute [atm abs]) or hypobaric pressure (34.4 kPa; 0.34 atm abs) once daily for 30 days and the control group was stored at atmospheric pressure for 30 days. The bond strength was tested with a universal testing machine and the failures were examined with a stereomicroscope and scanning electron microscope. Statistical analyses were performed using analysis of variance with post hoc tests, and the Weibull analysis.

RESULTS

Regardless of environmental pressure changes, the bulk-fill composites showed the highest bond strength. There was no significant difference in bond strength between the hypobaric and atmospheric pressure (control) groups after 30 days in all resins. The hyperbaric group showed lower bond strength for bulk-fill composites than the control group.

CONCLUSIONS

Dentists experienced in diving and aviation medicine should definitely take part in the initial and periodic medical examinations of divers and aircrew to give appropriate treatment. Bulk-fill composite resins can be preferred in divers and aircrew due to high bond strength values.

Nutritional status of patients referred for hyperbaric oxygen treatment; a retrospective and descriptive cross-sectional study

INTRODUCTION

Due to the global rise of obesity, the role of nutrition has gathered more attention. Paradoxically, even overweight persons may be malnourished. This may delay wound healing or recovery of late radiation tissue injury (LRTI). Hyperbaric oxygen treatment (HBOT) is used to improve wound healing or LRTI complaints. The aim of this study was to assess the dietary intake levels of nutrients important for recovery in patients referred for HBOT.

METHODS

This was a retrospective, cross-sectional study of patients referred for HBOT to a single centre between 2014 and 2019. Patients were offered a consultation with a dietitian as standard care. Information on nutrients was calculated from questionnaires, and compared to recommended daily allowances.

RESULTS

One hundred and forty-six patients were included (80 female). Eighteen patients were treated for diabetic ulcers, 25 for non-diabetic ulcers and 103 for LRTI. Most were overweight or obese (64.4%), but did not consume the recommended quantities of calories, protein, or micronutrients. Vitamin C consumption was higher than recommended. Male patients had a higher intake of calories and protein than female patients but not other nutrients. No differences in intake existed between age or body mass index categories.

CONCLUSIONS

The nutritional status of patients referred for HBOT may be inadequate for healing wounds or LRTI, despite anthropomorphic data indicating a positive energy balance. Daily attendance for HBOT provides a unique opportunity to monitor and correct these deficiencies. Routine screening for malnutrition and supplement deficiencies is recommended for patients referred for HBOT.

Adjuvant hyperbaric oxygen treatment of acute brain herniation after microsurgical clipping of a recurring cerebral aneurysm: a case report

INTRODUCTION

Acute brain herniation is a life-threatening neurological condition that occasionally develops due to severe complications following cerebral aneurysm clipping. Strategies for managing acute brain herniation have not improved substantially during the past decade. Hyperbaric oxygen treatment (HBOT) may alleviate harmful effects of cerebral hypoxia, which is one of the most important pathophysiological features of acute brain herniation and, therefore, may be useful as an adjuvant therapy for acute brain herniation. A case treated with adjuvant HBOT is reported.

CASE REPORT

A 60-year-old asymptomatic man presented with a recurring left middle cerebral artery bifurcation aneurysm with previous stent-assisted embolisation. After craniotomy for surgical clipping of the aneurysm, disturbance of consciousness and right hemiplegia occurred. Computed tomography (CT) images suggested simultaneous cerebral ischaemia and intracranial haemorrhage. Pharmacologic treatment resulted in no improvement. A CT scan acquired five days after surgery showed uncal and falcine herniation. HBOT was administered five days after surgery, and the patient's condition dramatically improved. He became conscious, and his hemiplegia improved following seven sessions of HBOT. Simultaneously, CT images showed regression of the acute brain herniation.

CONCLUSIONS

The patient had recovered completely at one year post-treatment. HBOT may be effective in the treatment of acute brain herniation following cerebral aneurysm clipping.

Efficacy and safety of hyperbaric oxygen treatment in SARS-COV-2 (COVID-19) pneumonia: a systematic review

INTRODUCTION

The need for intubation and mechanical ventilation among COVID-19 patients is associated with high mortality rates and places a substantial burden on the healthcare system. There is a strong pathophysiological rationale suggesting that hyperbaric oxygen treatment (HBOT), a low-risk and non-invasive treatment, may be beneficial for COVID-19 patients. This systematic review aimed to explore the potential effectiveness and safety of HBOT for treating patients with COVID-19.

METHODS

Medline, Embase, Scopus, and Google Scholar were searched from December 2019 to February 2021, without language restrictions. The grey literature was searched via an internet search engine and targeted website and database searches. Reference lists of included studies were searched. Independent reviewers assessed studies for eligibility and extracted data, with disagreements resolved by consensus or a third reviewer. Risk of bias was assessed using the Newcastle Ottawa Scale. Data were summarised descriptively.

RESULTS

Six publications (one cohort study, five case reports/series) met the inclusion criteria with a total of 37 hypoxaemic COVID-19 patients treated with HBOT. Of these 37 patients, the need for intubation and mechanical ventilation and in-hospital survival were assessed for 26 patients across three studies. Of these 26 patients, intubation and mechanical ventilation were not required for 24, and 23 patients survived. No serious adverse events of HBOT in COVID-19 patients were reported. No randomised trials have been published.

CONCLUSIONS

Limited and weak evidence from non-randomised studies including one propensity-matched cohort study suggests HBOT is safe and may be a promising intervention to optimise treatment and outcomes in hypoxaemic COVID-19 patients. Randomised controlled studies are urgently needed.

Comparison of venous, capillary and interstitial blood glucose data measured during hyperbaric oxygen treatment from patients with diabetes mellitus

INTRODUCTION

Patients undergoing hyperbaric oxygen treatments (HBOT) have been shown to experience a reduction in blood glucose (BG) levels during a treatment. This necessitates frequent assessment of BG levels. Continuous glucose monitoring (CGM) may represent an alternative to the current finger prick monitoring method in-chamber, however, continuous sensor glucose (SG) data has not been validated in situ. The aim was to determine the validity of continuous SG and intermittent BG monitoring with serum BG levels in diabetic patients during HBOT.

METHODS

Measurements were obtained (finger prick [capillary sample], CGM [interstitial fluid], and serum [venous sample]) at baseline, and at 30, 60, 90 and 120 minutes during the hyperbaric treatment. Data were analysed by calculating intraclass correlation coefficients (ICC) and using mixed effects linear regression.

RESULTS

The ICC results (n = 10 patients) between the three methods indicated very high and statistically significant absolute agreement at baseline (pre-dive) (ICC = 0.90, 95% CI 0.74-0.97), at 30 minutes (ICC = 0.85, 95% CI 0.61-0.96), 60 minutes (ICC = 0.86, 95% CI 0.58-0.96), 90 minutes (ICC = 0.87, 96% CI 0.63-0.96) and 120 minutes (ICC = 0.90, 95% CI 0.70-0.97). Capillary glucose and CGM SG readings were each within 1 mmol·L-1 on average of the serum glucose reading, with multi-level linear regression finding the average difference between the CGM SG and capillary glucose methods of BG sampling was not statistically significant (P = 0.81).

CONCLUSIONS

The CGM SG data were comparable with glucose readings from capillary monitoring. Both CGM and capillary data were consistent with serum values.

Long-term infant outcomes after hyperbaric oxygen treatment for acute carbon monoxide poisoning during pregnancy

INTRODUCTION

Carbon monoxide (CO) poisoning in pregnant women is linked to foetal mortality of 36-67%. This study assessed long-term fetal outcomes following hyperbaric oxygen treatment (HBOT) for acute CO poisoning in pregnant women. The effects of clinical severity parameters and pregnancy trimester were also analysed.

METHODS

A retrospective review of 28 pregnant patients who received HBOT for acute CO poisoning between January 2013-June 2016 was made. Adverse events, birth week, birth weight-height, birth complications, and the age of crawling, walking independently, talking (first words) of their children were recorded.

RESULTS

Twenty-eight singleton pregnancies were included. One fetus was dead before HBOT. Three adverse events were reported: abortion, premature birth, and limb malformation. All remaining patients (n = 24) delivered healthy term infants and reported normal neurophysiological development. At final interview the median age of babies was 34 (8-44) months and none had any diagnosed disease. There was no relationship between clinical severity parameters and long-term outcomes. However, the pregnancy trimester at the time of CO poisoning had a significant relationship to birth weight (P = 0.029). Also, the week of pregnancy at the time of the incident correlated with the age of walking independently (P = 0.043, r = 0.436).

CONCLUSIONS

This is the largest relevant series and longest follow-up to date. Adverse outcomes were likely incidental because the mothers' medical histories revealed alternative aetiologies. There was no definite evidence of fetal morbidity or mortality after HBOT in this study. HBOT may improve long-term fetal outcomes after in-utero CO poisoning without complications.

Effect of hyperbaric oxygen treatment on patients with reduced left ventricular ejection fraction

INTRODUCTION

Hyperbaric oxygen treatment (HBOT) is available to a wide spectrum of patients, many with significant co-morbidities. Considering its effects on cardiac physiology and reports of pulmonary oedema following exposure, concerns exist about the safety of patients with compromised cardiac function. Few studies have described adverse events occurring during HBOT and even fewer reports address events arising in the hours following HBOT. A relation between adverse events and cardiac function has not been established. As medical guidance is limited, we aimed to evaluate the risk for patients with reduced left ventricular ejection fraction (LVEF) receiving HBOT.

METHODS

This retrospective chart review of patients receiving HBOT from April 2003 through December 2019 at our hospital was designed to describe clinical characteristics of patients and to identify adverse events during HBOT and within 24 hours after HBOT. Patients ≥ 40 years of age with a documented LVEF of ≤ 40% were included. Data are presented as mean (SD) [range] or counts, as appropriate.

RESULTS

A total of 23 patients were included in the final analysis, 2 (1) [0-4] patients per year. Patients received 25 (19) [1-60] treatments. Two patients had an episode of acute decompensated heart failure possibly linked to HBOT.

CONCLUSIONS

This study described the clinical characteristics of patients with reduced LVEF receiving HBOT and showed reassuring results, with a majority of patients with reduced LVEF tolerating HBOT well. Prospective research is required to more fully assess the risk.

Results of hyperbaric oxygen treatment in an at-risk nasal flap following trauma

Hyperbaric oxygen treatment (HBOT) is widely used in otorhinolaryngology for various purposes. A 20-year-old male patient was admitted following a traumatic nasal wound which occurred several hours prior. He had a nasal glass cut from the radix to the supratip area which was primarily closed by non-absorbable suture. The following day, there was a haematoma and necrosis of the skin. The haematoma was drained under local anaesthesia. Blood supply to the nasal skin was severely compromised and only the columellar artery remaining intact, by definition designating this a difficult to heal wound with the risk of overall healing failure. Necrosis of the skin had developed within the first 24 hours. Accordingly, the patient underwent 30 HBOT sessions (two hours at 253.3 kPa) twice daily for four days and daily thereafter. Antibiotic cover and conservative wound management were also used. Complete healing was achieved without the need for additional surgical intervention. We conclude that timely use of HBOT may be a valuable adjunct to conservative wound management in a case of sharp nasal trauma.

Hyperbaric oxygen treatment for toxic epidermal necrolysis: A case report

Toxic epidermal necrolysis (TEN) is a potentially life-threatening muco-cutaneous disease, largely caused by an idiosyncratic reaction to medication or infectious disease, and is characterised by acute necrosis of the epidermis. No definitive consensus regarding the treatment of TEN has been agreed. A 60-year-old woman, diagnosed with multiple myeloma three months prior, was admitted with signs of TEN to the intensive care burns unit. She had been given ciprofloxacin to treat a urinary tract infection. She complained of malaise and pain, with maculopapular and bullous eruptions over her whole body on the third day of ciprofloxacin administration. Her supportive cares included intravenous immunoglobulins, pain control with analgesics, wound care, nutrition, and fluid support. Hyperbaric oxygen treatment (HBOT) was added on the second day of admission. The patient underwent 5 sessions of HBOT at 243.1 kPa (2.4 atmospheres absolute). Desquamation was noted to stop after the first session of HBOT and re-epithelisation commenced rapidly. The patient was discharged from the burn unit after 14 days of hospital admission. Improvement in this case was temporally related to the initiation of HBOT.

Urgent hyperbaric oxygen therapy for suicidal carbon monoxide poisoning: from a preliminary survey to a proposal for an integrated somatic-psychiatric protocol

A considerable number of patients who made a carbon monoxide (CO) suicidal attempt are treated with urgent hyperbaric oxygen therapy (HBOT). For these patients at potential persistent risk of suicide, the hyperbaric chamber is a dangerous environment and their management a complex challenge for the Emergency Department (ED) and Hyperbaric Medicine Unit (UMH) teams. We aimed to (1) identify cases of intentional CO poisoning treated with urgent HBOT in the UMH of the University Hospitals of Geneva (HUG) during 2011-2018 and (2) test a proposed operational and integrated somatic-psychiatric protocol based on acquired experience. A total of 311 patients with CO poisoning were treated using urgent HBOT, for which poisoning was assumed suicidal in 40 patients (12.9%). This percentage appears greater than in other European countries. Both the excess of cases of intentional CO poisonings and difficulties encountered in their management resulted in the implementation of an operational and integrated somatic-psychiatric protocol addressing the entire patient's clinical trajectory, from the admission at ED-HUG to the treatment at the UMH-HUG. The established institutional protocol includes (1) clinical evaluation, (2) suicide risk assessment, and (3) safety measures. This is the first report-at our best knowledge-of a protocol detailing a practical procedure algorithm and focusing on multidisciplinary and mutual collaboration between the medical-nursing teams at the ED, psychiatric ED, and UMH. Improvements in patient's safety and care team's sense of security were observed. In conclusion, the opportunity to refer to a standardized protocol was beneficial in that it offers both reduced risks for suicidal patients and reduced stress for care teams operating in very acute and complex situations. Further studies are needed.

Role of Hyperbaric Medicine for Osteoradionecrosis and Post Irradiation Wounds: an Institutional Experience

To study the effectiveness of hyperbaric medicine in osteoradionecrosis and irradiation induced wounds. To evolve a protocol for management with combined surgical modality for irradiation induced injury. This study was carried out in the Plastic Surgery Department, from November 2011 to December 2018. A total of 30 patients with post irradiation patients subjected to hyperbaric oxygen therapy during the management were enrolled in the study. The results regarding the changes in wound and complications were noted. Out of 30 patients, 20 patients were with radiation injury involving the oral cavity, one patient with left lower limb, one with breast, 3 with radiation injury of cheek, 3 of mandible, one with radiation cystitis and one involving the tooth socket. One patient experienced reversible myopia as a complication of hyperbaric therapy. No other complications were noted. Hyperbaric therapy is a useful adjunct for surgery in management of osteoradionecrosis and post irradiation wound and proves therapeutic in some post irradiated wound where we cannot offer surgical correction.

The effect of hyperbaric oxygen treatment on late radiation tissue injury after breast cancer: A case-series of 67 patients

INTRODUCTION

Late radiation tissue injury (LRTI) after breast cancer may benefit from hyperbaric oxygen treatment (HBOT). This study aimed to report the LRTI symptom scores up to 12 months after HBOT and identify risk factors for poor scores.

METHODS

A case-series of 67 patients who underwent a mean of 44 sessions of HBOT was analysed. LRTI symptoms were scored at four time points using the LENT-SOMA scale (Late Effects in Normal Tissues - Subjective, Objective, Management, and Analytic), a visual analog scale for pain, and the range of shoulder motion.

RESULTS

Between starting HBOT and 12 months after HBOT 57 patients (85%) reported at least one point improvement in their LENT-SOMA score. Median pain and fibrosis scores improved significantly between the start and end of HBOT (P < 0.001), and remained stable three and 12 months after HBOT. The median breast oedema score improved significantly 12 months after HBOT (P = 0.003). Median shoulder abduction increased significantly from 90 to 165 degrees (P = 0.001) and median shoulder anteflexion increased significantly from 115 to 150 degrees (P = 0.004). Various risk factors were identified for poor scores despite HBOT; the most common risk factor was a poor score at start of HBOT.

CONCLUSIONS

In this case-series, patients who underwent HBOT for LRTI after breast cancer reported significant improvement in pain, fibrosis, oedema, and shoulder movement. The improvement persisted up to 12 months after HBOT. A poor score at the start of HBOT was predictive for a poor score 12 months after HBOT.

Inhibition of NR2B-containing NMDA receptors during nitrogen narcosis

INTRODUCTION

When humans breathe compressed air or N₂-O₂ mixtures at three to four atmospheres pressure, they will experience nitrogen narcosis that may possibly lead to a diving accident, but the underlying mechanisms remain unclear.

METHODS

Mice were exposed to 1.6 MPa breathing a N₂-O₂ mixture adjusted to deliver an inspired PO₂ of 32-42 kPa. The electroencephalogram (EEG) and forced swimming test were used to evaluate the narcotic effect of nitrogen. Neuronal activity was observed via c-Fos expression in cortex and hippocampus tissue after decompressing to the surface. To further investigate underlying molecular mechanisms, we incubated cultured hippocampal neurons with various NMDA concentrations, and measured expression of NMDA receptors and its down-stream signal with or without 1.6 MPa N₂-O₂ exposure.

RESULTS

Both the frequency of the EEG and the drowning time using the forced swimming test were significantly decreased during exposure to 1.6 MPa N₂-O₂ (P < 0.001). Additionally, in cultured hippocampal neurons, the increased levels of phosphorylated NR2B and cAMP-response element binding protein (CREB) induced by NMDA stimulation were significantly inhibited by exposure to 1.6 MPa N₂-O₂.

CONCLUSIONS

Our findings indicated that NR2B-containing NMDA receptors were inhibited during nitrogen narcosis.

Clinical and morphological effects of hyperbaric oxygen therapy in patients with interstitial cystitis associated with fibromyalgia

Background

Interstitial Cystitis (IC) is a debilitating disorder of the bladder, with a multifactorial and poorly understood origin dealing with microcirculation repeated damages. Also Fibromyalgia (FM) is a persistent disorder whose etiology is not completely explained, and its theorized alteration of pain processing can compromise the quality of life. Both these conditions have a high incidence of conventional therapeutic failure, but recent literature suggests a significant beneficial response to Hyperbaric Oxygen Therapy (HBOT). With this study, this study we evaluated the effects of HBOT on quality of life, symptoms, urodynamic parameters, and cystoscopic examination of patients suffering from both IC and FM.

Methods

We structured an observational clinical trial design with repeated measures (questionnaires, urodynamic test, and cystoscopy) conducted before and 6 months after a therapeutic protocol with hyperbaric oxygen for the treatment of patients suffering from both IC and FM. Patients were exposed to breathing 100% oxygen at 2 atm absolute (ATA) in a multiplace pressure chamber for 90 min using an oro-nasal mask. Patients undertook a cycle of 20 sessions for 5 days per week, and a second cycle of 20 sessions after 1 week of suspension.

Results

Twelve patients completed the protocol. Changes after HBOT were not significant, except for hydrodistension tolerance (mean pre-treatment: 409.2 ml; mean post-treatment: 489.2 ml; p < 0.05). A regression of petechiae and Hunner’s ulcers was also noted 6 months after the completion of HBOT.

Conclusions

Our study showed no improvement of symptoms, quality of life, and urodynamic parameters, except for hydrodistension, and a slight improvement in cystoscopic pattern. However, to date, we could not demonstrate the significance of overall results to justify the use of HBOT alone in patients with IC and FM. This observation suggests that additional studies are needed to better understand if HBOT could treat this subset of patients.

Trial registration

NCT03693001; October 2, 2018. Retrospectively registered.

Is there a role for hyperbaric oxygen therapy in the treatment of refractory wounds of rare etiology?

INTRODUCTION

Delayed wound healing indicates wounds that have failed to respond to more than 4-6 weeks of comprehensive wound care. Wounds with delayed healing are a major source of morbidity and a major cost to hospital and community healthcare providers. Hyperbaric oxygen therapy (HBOT) is a treatment designed to increase the supply of oxygen to wounds and has been applied to a variety of wound types. This article reviews the place of HBOT in the treatment of non-healing vasculitic, calcific uremic arteriolopathy (CUA), livedoid vasculopathy (LV), pyoderma gangrenosum (PG) ulcers.

METHODS

We searched electronic databases for research and review studies focused on HBOT for the treatment of delayed healing ulcers with rare etiologies. We excluded HBOT for ulcers reviewed elsewhere.

RESULTS

We included a total of three case series and four case reports including 63 participants. Most were related to severe, non-healing ulcers in patients with vasculitis, CUA, LV, and PG. There was some evidence that HBOT may improve the healing rate of wounds by increasing nitric oxide (NO) levels and the number of endothelial progenitor cells in the wounds. HBOT may also improve pain in these ulcers.

CONCLUSION

We recommend the establishment of comprehensive and detailed wound care registries to rapidly collect prospective data on the use of HBOT for these problem wounds. There is a strong case for appropriately powered, multi-centre randomized trials to establish the true efficacy and cost-effectiveness of HBOT especially for vasculitis ulcers that have not improved following immunosuppressive therapy.

Treatment preferences for decompression illness amongst Singapore dive physicians

INTRODUCTION

Owing to the scarcity of randomized controlled trials to guide treatment for decompression illness (DCI), there are many unanswered questions about its management. Apart from reviews and expert opinion, surveys that report practice patterns provide information about useful management strategies. Hence, this study aimed to identify current treatment preferences for DCI amongst diving physicians in Singapore.

METHODS

An anonymous web-based questionnaire was sent to known diving physicians in Singapore. The demographics of the respondents were captured. Respondents were asked about their preferred management for five different DCI scenarios.

RESULTS

The response rate was 74% (17 of 23 responses). All respondents chose to recompress patients described in the five scenarios. Regarding the number of recompression sessions, "one additional session after no further improvement in signs and symptoms" was the most common end point of treatment across all the scenarios (47 of 85 responses). Analgesics would be used by five physicians, three would use lidocaine and two steroids as adjuvant therapies.

CONCLUSIONS

Apart from the general agreement that recompression is indicated for DCI, there was no strong consensus regarding other aspects of management. This survey reinforces the need for robust RCTs to validate the existing recommendations for DCI treatment.

Performance of the BBraun perfusor space syringe driver under hyperbaric conditions

BACKGROUND

The BBraun Perfusor Space™ syringe driver is already in use by ambulance services and retrieval teams but has not previously been assessed for hyperbaric chamber use.

METHODS

Pump flow accuracy was tested at rates between 1 and 40 ml· h⁻¹ using three different brands of 50 ml syringe. Function of the occlusion alarms was assessed using the same syringes. The hyperbaric profile involved pressurisation to 284 kPa at 30 kPa· min⁻¹, 30 min at 284 kPa and decompression at 30 kPa· min⁻¹. Output was recorded from differences in weight of collection containers. A single device was tested.

RESULTS

Performance was highly dependent on the syringe type used, with two of the three 50 ml syringes used demonstrating 'stiction' at both low and high occlusion pressure alarm settings, most marked during pressurisation. On decompression from 284 kPa all syringes alarmed at significantly lower pressures. Because of the stiction problems only the flow measurements for the BBrown Omni¬ x 50 ml syringes are reported. At a pressure of 284 kPa, the difference between programmed and delivered rates was within the manufacturer's specification of 10%: at 40 ml· h⁻¹ (median variation 1.25%, IQR 0.5-1.7%), 10 ml· h⁻¹ (8.6%, IQR 8-9.2%), 5 ml· h⁻¹ (-8.8%, IQR - 1.6-8.8%) and 1 ml· h⁻¹ (-4%, IQR 4-12%). Pressurisation was associated with significantly lower flow rates whilst decompression was associated with significantly increased rates. Limited testing at 405 kPa was also within the manufacturer's specifications.

CONCLUSION

A BBraun Infusor Space syringe driver performed within acceptable performance criteria but is highly dependent on syringe type and flow rates. The potential for the device to under deliver on pressurisation and over deliver on depressurisation, however, suggests vigilance and appropriate rate adjustments may be necessary during these phases.

Medical devices and procedures in the hyperbaric chamber

The aim of this paper is to present current controversies concerning the safety of medical devices and procedures under pressure in a hyperbaric chamber including: defibrillation in a multiplace chamber; implantable devices during hyperbaric oxygen treatment (HBOT) and the results of a recent European questionnaire on medical devices used inside hyperbaric chambers. Early electrical defibrillation is the only effective therapy for cardiac arrest caused by ventricular fibrillation or pulseless ventricular tachycardia. The procedure of defibrillation under hyperbaric conditions is inherently dangerous owing to the risk of fire, but it can be conducted safely if certain precautions are taken. Recently, new defibrillators have been introduced for hyperbaric medicine, which makes the procedure easier technically, but it must be noted that sparks and fire have been observed during defibrillation, even under normobaric conditions. Therefore, delivery of defibrillation shock in a hyperbaric environment must still be perceived as a hazardous procedure. Implantable devices are being seen with increasing frequency in patients referred for HBOT. These devices create a risk of malfunction when exposed to hyperbaric conditions. Some manufacturers support patients and medical practitioners with information on how their devices behave under increased pressure, but in some cases an individual risk-benefit analysis should be conducted on the patient and the specific implanted device, taking into consideration the patient's clinical condition, the indication for HBOT and the capability of the HBOT facility for monitoring and intervention in the chamber. The results of the recent survey on use of medical devices inside European hyperbaric chambers are also presented. A wide range of non-CE-certified equipment is used in European chambers.

Mind the gap: Management of an emergent and threatening invasive fungal infection-a case report of rhino-orbital-cerebral and pulmonary mucormycosis

Mucormycosis is an emergent and threatening invasive fungal invasion underdiagnosed by clinicians due to lack of awareness and aspecific clinical picture. The authors describe a clinical case of a diabetic and cirrhotic patient who developed rhino-orbital-cerebral and pulmonary mucormycosis, non-responsive to treatment. Typical gaps in the management of this deadly disease are addressed. There is a strong need for novel therapies and an expectation that sponsors will recognize the critical need for randomized clinical trials.