Effects of high oxygen tension on healthy volunteer microcirculation.

INTRODUCTION: Previous studies have highlighted hyperoxia-induced microcirculation modifications, but few have focused on hyperbaric oxygen (HBO) effects. Our primary objective was to explore hyperbaric hyperoxia effects on the microcirculation of healthy volunteers and investigate whether these modifications are adaptative or not. METHODS: This single centre, open-label study included 15 healthy volunteers. Measurements were performed under five conditions: T0) baseline value (normobaric normoxia); T1) hyperbaric normoxia; T2) hyperbaric hyperoxia; T3) normobaric hyperoxia; T4) return to normobaric normoxia. Microcirculatory data were gathered via laser Doppler, near-infrared spectroscopy and transcutaneous oximetry (PtcO2). Vascular-occlusion tests were performed at each step. We used transthoracic echocardiography and standard monitoring for haemodynamic investigation. RESULTS: Maximal alterations were observed under hyperbaric hyperoxia which led, in comparison with baseline, to arterial hypertension (mean arterial pressure 105 (SD 12) mmHg vs 95 (11), P < 0.001) and bradycardia (55 (7) beats·min⁻¹ vs 66 (8), P < 0.001) while cardiac output remained unchanged. Hyperbaric hyperoxia also led to microcirculatory vasoconstriction (rest flow 63 (74) vs 143 (73) perfusion units, P < 0.05) in response to increased PtcO2 (104.0 (45.9) kPa vs 6.3 (2.4), P < 0.0001); and a decrease in laser Doppler parameters indicating vascular reserve (peak flow 125 (89) vs 233 (79) perfusion units, P < 0.05). Microvascular reactivity was preserved in every condition. CONCLUSIONS: Hyperoxia significantly modifies healthy volunteer microcirculation especially during HBO exposure. The rise in PtcO2 promotes an adaptative vasoconstrictive response to protect cellular integrity. Microvascular reactivity remains unaltered and vascular reserve is mobilised in proportion to the extent of the ischaemic stimulus.

Treating ARDS-associated air embolism: a question of priorities.

Gas embolism is a potential and often life-threatening complication of central venous catheters. We report a case of air embolism after tearing of the central catheter associated with severe acute respiratory distress syndrome. The severity of the clinical situation meant choices had to be made regarding the order of treatments. This clinical case provided useful eye-openers for patient management regarding the prioritization of treatments as well as the possibilities offered by hyperbaric oxygen therapy.

Evaluation of pressure in water-filled endotracheal tube cuffs in intubated patients undergoing hyperbaric oxygen treatment.

INTRODUCTION: Inflating endotracheal tube cuffs using water instead of air before hyperbaric oxygen treatment (HBOT) is common. The objective of this study was to assess cuff pressure (Pcuff), when the cuff was inflated using water, in normobaric conditions and during HBOT. METHODS: This was a prospective, observational study taking place in hyperbaric centre and intensive care unit of the University Hospital of Lille. Every patient who required tracheal intubation and HBOT at 253.3 kPa (2.5 atmospheres absolute [atm abs]) was included. Pcuff was measured using a pressure transductor connected to the cuff inflating port. Measurements were performed at 'normobaria' (1 atm abs) and during HBOT at 2.5 atm abs. RESULTS: Thirty patients were included between February and April 2016. Recordings were analysable in 27 patients. Mean Pcuff at normobaria was 60.8 (SD 42) cmH2O. Nineteen (70%) of patients had an excessive Pcuff (higher than 30 cmH2O). Coefficient of variation was 69%. Mean Pcuff at 2.5 atm abs was 51.6 (40.7) cmH2O, significantly lower than at normobaria (P < 0.0001). Coefficient of variation was 79%. In only five (18%) patients was Pcuff < 20 cmH2O at 2.5 atm abs. CONCLUSIONS: In normobaric conditions, when the cuff was inflated using water and not specifically controlled Pcuff was not predictable. The cuff was typically over-inflated exceeding safe pressure. During HBOT Pcuff decreased slightly.

Endocan regulates acute lung inflammation through control of leukocyte diapedesis.

Acute respiratory distress syndrome is a severe form of respiratory failure, occurring in up to 20% of patients admitted to the intensive care unit with sepsis. Dysregulated leukocyte diapedesis is a major contributor to acute respiratory distress syndrome. Endocan is a circulating proteoglycan that binds to the leukocyte integrin leukocyte functional antigen-1 and blocks its interaction with its endothelial ligand, ICAM-1. The objective of this study was to evaluate the role of endocan in the control of acute lung inflammation. In vitro, endocan inhibited human leukocyte transendothelial migration as well as ICAM-1-dependent migration but had a very mild effect on ICAM-1-dependent adhesion. Endocan also acted as an inhibitor of transendothelial migration of mouse leukocytes. The effect of systemic administration of recombinant human endocan was assessed in a model of acute lung inflammation in BALB/c mice. Treatment with endocan 1 h after intratracheal LPS challenge reduced the alveolar inflammatory response, diminished histological features of acute lung injury, and improved respiratory function. These results highlight the anti-inflammatory role of human endocan and its protective effect against acute lung injury.NEW & NOTEWORTHY We show here that endocan inhibits ICAM-1-dependent human leukocyte transendothelial migration and ICAM-1-dependent adhesion. We also found that in BALB/c mice with tracheal LPS-induced acute lung injury treatment with recombinant human endocan reduces lung inflammation, notably through reduction of neutrophilic recruitment, and restores normal lung function. These results confirm the hypothesis that human endocan may have a protective effect against acute lung inflammation.

[Carbon monoxide poisoning]. / Intoxication au monoxyde de carbone.

Carbon monoxide poisoning. Carbon monoxide poisoning is a frequent and serious intoxication with an important pre-hospital mortality. The diagnosis is made by the association of a context and compatible neurological and cardiac clinical signs. This diagnosis is now eased by home or firefighters detectors. Management is based primarily on the extraction of the toxic atmosphere and the administration of oxygen in emergency and, according to clinical presentation or context, hyperbaric oxygen therapy. This specialized therapy is necessary when exist any objective clinical sign, loss of consciousness or pregnancy. It aims to reduce the risk of neuropsychological and cognitive sequelae. Prevention of this intoxication is essential and motivates its reporting to the regional health agency.

Intoxication au monoxyde de carbone. L'intoxication au monoxyde de carbone est une intoxication fréquente et grave grevée d'une mortalité préhospitalière encore importante. Le diagnostic se fait par l'association d'un contexte et de signes cliniques neurologiques et cardiaques compatibles. Ce diagnostic est maintenant facilité grâce aux détecteurs de CO placés à domicile ou portés par les pompiers. La prise en charge repose surtout sur l'extraction de l'atmosphère toxique et l'administration d'oxygène normobare en urgence et, selon les signes présentés, une oxygénothérapie hyperbare. Cette thérapie spécialisée est nécessaire devant tout signe objectif clinique, perte de connaissance ou grossesse. Elle a pour but de diminuer le risque de séquelles neuropsychologiques liées au syndrome post-intervallaire. La prévention de cette intoxication est essentielle et motive sa déclaration à l'agence régionale de santé.

Correction to Mathieu D, Marroni A, Kot J: Tenth European Consensus Conference on Hyperbaric Medicine: recommendations for accepted and non-accepted clinical indications and practice of hyperbaric oxygen treatment. Diving Hyperb Med. 2017 Mar;47(1):24-32.

Consistent with the Committee on Publication Ethics guidelines, we the above authors are initiating a partial retraction and correction of our paper: Mathieu D, Marroni A, Kot J: Tenth European Consensus Conference on Hyperbaric Medicine: recommendations for accepted and non-accepted clinical indications and practice of hyperbaric oxygen treatment. Diving Hyperb Med. 2017 Mar;47(1):24-32. We wish to make the following statement: "Regardless of the strict process of editing and proof-reading of tables included in the above-mentioned publication, we received some comments from readers which showed us that imperfect layout of Table 1 and incorrect layout of Table 2 changed significantly the conclusions which could be drawn from them. Table 1 described the relation between strength of recommendations given by the Jury of the Consensus Conference and the level of evidence based on the GRADE system. There should be a clear and straight relation showing that Level 1 "strong recommendation" should be based on GRADE A "high level of evidence (LOE)", Level 2 "weak recommendation" should be based on GRADE B "moderate LOE", Level 3 "neutral recommendation" should be based on GRADE C "low LOE" and finally no recommendation should be given when only GRADE D "very low LOE" are present. Note that there is no change to the content of the table, but only visual representation of this relationship. Table 2 has been incorrectly printed. In fact, there is no GRADE A LOE. All X marks placed in the column A should be moved to the right, to GRADE B LOE. In the same way, all X marks placed in the column B should be moved to the right, to GRADE C LOE. We voluntarily retract these tables from the above-mentioned publication, expressing our regret for the situation."

ECHM Consensus Conference and levels of evidence - Reply.

Dr Sherlock asks for clarification on the approach adopted by the European Committee on Hyperbaric Medicine (ECHM) to assessing evidence for establishing indications for hyperbaric oxygen treatment (HBOT). Firstly, regardless of the strict process of editing and proof-reading of tables included in the above-mentioned publication, we received comments from some readers that identified imperfect layout of Table 1 and incorrect layout of Table 2 which significantly changed the conclusions to be drawn from them. This concerned both the details of the methodology used and description of the ECHM recommendations and associated levels of evidence. Therefore, those tables are republished in their correct forms in this issue, hoping that this will explain at least some of the doubts and misunderstandings. Both the Editor and ourselves apologise for these errors of publication. Secondly, in the ECHM Consensus Conference methodology, we scored the evidence for clinical studies requiring double-blind randomised controlled trials (RCT) as Level A and B when, at the same time, some scoring scales require simply 'RCT', as correctly pointed out by Dr Sherlock. Long experience in organising evidence based medicine (EBM) meetings and discussions has taught us that RCTs that are not double blinded are often criticised as having serious potential bias and so are denied as level A evidence. Although we acknowledge that double blinding a clinical study in HBOT is a source of difficulty, we chose a priori to consider only double-blinded RCTs in our grading scale to avoid endless discussions about this potential bias. We are well aware that doing so means that Level A evidence is a difficult target for the hyperbaric community. We agree that many evidence scoring systems have a low level of inter-observer agreement. This is why we treat the Consensus Conference as a valuable tool that provides a better opportunity for discussing the evidence than analysis by a small group of 'experts'. This is because the whole process is transparent and available to all participants' comments and input. The final process of voting by the audience after the general discussion thus truly reflects the position of the professional hyperbaric community in Europe on the issued recommendations. By these two mechanisms, the blind application of disputable evidence scoring systems may be avoided or, at least, decreased. Thirdly, the problem of 'sham' treatments in hyperbaric research has been raised. While this has been discussed many times in the past, hyperbaric research is not the sole field where such sham treatment raises some difficulty. Surgery is probably the best example where RCTs with control arms utilising sham surgical procedures (possibly including the administration of anaesthesia) are rare and can raise major ethical problems. Nevertheless, from an EBM viewpoint, the difficulty of designing a double-blind study is never taken into account during evaluation of clinical studies. Finally, Dr Sherlock pointed out her doubts on the recommendations issued by the ECHM on idiopathic sudden sensorineural hearing loss (ISSHL). While there is no possibility to cite here the full experts' report on that issue presented during the conference, we understand that a detailed report from the Conference is being prepared for publication. In brief, the strength of evidence has been scored as Level B, in general agreement with the last Cochrane review and the UHMS Committee report. Based on this level of evidence, the Type 1 recommendation was issued with the agreement of the large majority of the Consensus Conference participants.

Tenth European Consensus Conference on Hyperbaric Medicine: recommendations for accepted and non-accepted clinical indications and practice of hyperbaric oxygen treatment.

The tenth European Consensus Conference on Hyperbaric Medicine took place in April 2016, attended by a large delegation of experts from Europe and elsewhere. The focus of the meeting was the revision of the European Committee on Hyperbaric Medicine (ECHM) list of accepted indications for hyperbaric oxygen treatment (HBOT), based on a thorough review of the best available research and evidence-based medicine (EBM). For this scope, the modified GRADE system for evidence analysis, together with the DELPHI system for consensus evaluation, were adopted. The indications for HBOT, including those promulgated by the ECHM previously, were analysed by selected experts, based on an extensive review of the literature and of the available EBM studies. The indications were divided as follows: Type 1, where HBOT is strongly indicated as a primary treatment method, as it is supported by sufficiently strong evidence; Type 2, where HBOT is suggested as it is supported by acceptable levels of evidence; Type 3, where HBOT can be considered as a possible/optional measure, but it is not yet supported by sufficiently strong evidence. For each type, three levels of evidence were considered: A, when the number of randomised controlled trials (RCTs) is considered sufficient; B, when there are some RCTs in favour of the indication and there is ample expert consensus; C, when the conditions do not allow for proper RCTs but there is ample and international expert consensus. For the first time, the conference also issued 'negative' recommendations for those conditions where there is Type 1 evidence that HBOT is not indicated. The conference also gave consensus-agreed recommendations for the standard of practice of HBOT.

Poorly designed research does not help clarify the role of hyperbaric oxygen in the treatment of chronic diabetic foot ulcers.

Diabetic foot ulcers (DFUs) are one of the most common indications for hyperbaric oxygen treatment (HBOT). The role of HBOT in DFUs is often debated. Recent evidence based guidelines, while recommending its use, urge further studies to identify the patient subgroups most likely to benefit from HBOT. A recent study in Diabetes Care aimed to assess the efficacy of HBOT in reducing the need for major amputation and improving wound healing in patients with chronic DFUs. In this study, patients with Wagner grade 2-4 diabetic foot lesions were randomly assigned to have HBOT (30 sessions/90 min/244 kPa) or sham treatment (30 sessions/90 min/air/125 kPa). Six weeks after the completion of treatment (12 weeks after randomization) neither the fulfillment of major amputation criteria (11/49 vs. 13/54, odds ratio 0.91 [95% CI 0.37, 2.28], P = 0.846) nor wound-healing rates (20% vs. 22%, 0.90 [0.35, 2.31], P = 0.823) significantly differed between groups. The authors concluded that HBOT does not offer any additional advantage over comprehensive wound care. Since this paper was published in Diabetes Care, one of the most prestigious diabetes journals, it is likely it will have a major impact on the clinical practice of many physicians dealing with diabetic foot problems. Although from a methodological standpoint the conduct of the study (prospective, double-blind, randomized, controlled) seems to be close to ideal, several significant flaws render the conclusions weak. Firstly, there were some problems with the assessment of the primary outcome of "meeting the criteria for amputation". In their published protocol paper, the trial lists indicated that "At the end of the 6-week follow-up phase……, the patient is sent to the participating vascular surgeon for an amputation evaluation". However, in the published report in Diabetes Care, it is evident that patients were not assessed in a face-to-face consultation, but rather by the remote examination of wound photographs and clinical data "Participant clinical data together with digital photographs of the study wound progress were presented to the vascular surgeon". This departure from the original intent undermines the primary outcome of the study significantly. Fedorko et al claim this method of assessment has been validated, but neither of their supporting citations appear to substantiate this claim. Wirthlin et al assessed the level of agreement about a collection of wounds between surgeons who were present at the bedside and a remote group who assessed the wounds using a short clinical account and digital photography. There was reasonable agreement between onsite and remote, although the specificity for particular signs ranged from just 27% (erythema) to 100% (ischaemia). Importantly, only a subset of eight of the 24 included patients had non-healing wounds and the proportion of those that were associated with diabetes mellitus is unknown. Further, the need for amputation was not among the management decisions examined. Wirthlin et al concluded "a prospective trial of remote wound management …. is needed to further validate this technology." The authors of the second supposedly supporting citation were mainly interested in the assessment of pressure ulcers by digital photography using the Photographic Wound Assessment Tool (PWAT) compared to the Pressure Sore Status Tool (PSST). Of the 81 included lower leg ulcers, it is not clear how many were associated with diabetes mellitus. Indications for amputation were not considered. The authors concluded "The PWAT may be valuable when a bedside assessment cannot be made. However, the size of circular wounds, wound depth, undermining/tunneling, and odor cannot be assessed using photographs." In the Fedorko paper, the decision that there was an indication for amputation was made by the remote vascular surgeon by meeting any of the following criteria: "persistent deep infection involving bone and tendons (antibiotics required, hospitalization required, pathogen involved); ongoing risk of severe systemic infection related to the wound; inability to bear weight on the affected limb; or pain causing significant disability". We are particularly concerned that the criteria, "persistent deep infection involving bone and tendons", is subjective. Recent studies have demonstrated that diabetic foot osteomyelitis may not necessarily require amputation and some cases may be cured with antibiotic therapy alone. It is interesting to note that despite the high numbers of participants assessed as fitting the requirements for amputation (23% overall), no patient actually had a major amputation. The amputation outcome is inappropriately assessed, done at the wrong time, and the study is grossly underpowered to find any difference in the rate of true major amputation. Finally, whether the surgeon performed a baseline assessment of amputation prior to the randomised intervention is unknown. A comparison between the pre- and post-study estimates of amputation rates could have contributed to the interpretation of the results. Secondly, the authors fail to provide a clear comparison of peripheral arterial disease (PAD) between the groups. Although patients were randomized and those who were possible candidates for major vessel revascularization were excluded from the study, microvascular status was not assessed. No transcutaneous oxygen measurements were made on any of the patients. Given that, firstly, the risk of microvascular vessel compromise increases with diabetes duration, and secondly, transcutaneous oxygen measurements correlate with the possibility of good response to HBOT, it is possible that clinically significant differences between groups were undetected. As an example, patients in the HBOT group had a markedly longer mean duration of diabetes (19.1 vs. 12.4 years) and would be likely to have more severe microvascular disease. Thirdly, the follow-up period of six weeks after completion of treatment is very short. The study to which the authors refer to justify this follow-up period enrolled only patients with ulcers of Wagner grade 1 or 2 and specifically excluded patients with infection or ischaemia. These are not representative of the patient population treated with HBOT. The outcomes in patients with DFUs treated with HBOT should be assessed over a longer period. One such randomized controlled study demonstrated that patients receiving HBOT had significantly higher healing rates than placebo at one-year follow-up (25/48 (52%) versus 12/42 (29%); P 〈 0.03), but not at 12 weeks. Fourthly, the authors also failed to describe the experience of the vascular surgeon who adjudicated the wounds for amputation; how many years he was involved in the management of diabetic foot wounds or how specialized his practice was with these patients. Objective and universally recognized indications for amputation are yet to be established. Therefore, a multidisciplinary decision-making approach, rather than a single physician's decision, would have increased the credibility of the conclusion the authors reached. Notably, all previous studies of HBOT in this area have used actual amputation rates in order to have a clear clinical endpoint. Careful patient selection is paramount for the cost-effective use of HBOT as an adjunct to normal wound care in diabetic wounds. As it is possible to identify wounds that have no potential to heal despite HBOT, all studies should incorporate transcutaneous oxygen measurements in their baseline evaluation. As the wounds in this study tended to be small (6.1cm² and 5.8cm² on average) and had persisted for (on average) one year despite state-of-the-art previous wound care, it is likely that at least some of these would not meet the predictive minimal criteria for healing potential with HBOT. The findings of this study do indeed show that the indiscriminate treatment of all diabetic wounds with HBOT is probably not (cost-) effective; however, the study conclusion that "HBO has no benefit in the treatment of chronic diabetic foot wounds" is erroneous.

Hyperbaric oxygen therapy for intensive care patients: position statement by the European Committee for Hyperbaric Medicine.

Many of the accepted indications for hyperbaric oxygen treatment (HBOT) may occur in critically ill patients. HBOT itself may cause a number of physiological changes which may further compromise the patient's state. Guidelines on the management of critically ill patients in a hyperbaric facility have been founded on the conclusions of the 2007 European Committee for Hyperbaric Medicine (ECHM) meeting. With regard to patient management, HBOT should be included in the overall care of ICU patients only after a risk/benefit assessment related to the specifics of both the hyperbaric centre and the patient's clinical condition and should not delay or interrupt their overall management. Neither patient monitoring nor treatment should be altered or stopped due to HBOT, and any HBOT effects must be strictly evaluated and appropriately mitigated. With regard to the hyperbaric facility itself, the hyperbaric chamber should be specifically designed for ICU patients and should be fully equipped to allow continuation of patient monitoring and treatment. The hyperbaric chamber ideally should be located in, or around the immediate vicinity of the ICU, and be run by a sufficiently large and well-trained team of physicians, nurses, chamber operators and technicians. All devices to be introduced into the chamber should be evaluated, tested and acknowledged as safe for use in a hyperbaric environment and all procedures (standard and emergency) should be tested and written before being implemented.

[A 25-year study (1983-2008) of children's health outcomes after hyperbaric oxygen therapy for carbon monoxide poisoning in utero]. / Devenir des enfants intoxiqués au monoxyde de carbone en période foetale et traités par oxygéno- thérapie hyperbare--etude d'une cohorte constituée sur 25 ans de 1983 a 2008.

Carbon monoxide (CO) poisoning during pregnancy can be fatal for the fetus, or cause bone malformations or encephalopathy, depending on the stage of pregnancy at which the poisoning occurs. Fewer cases of death and encephalopathy have been reported since the adoption of maternal hyperbaric oxygen (HBO) therapy in this setting, but these children's long-term psychomotor development and growth remains to be documented. A prospective single-center cohort study spanning 25 years (1983 - 2008) included all pregnant women living in the Nord-Pas-de-Calais region of France who received HBO for CO poisoning and who gave birth to a living child. A descriptive analysis of the women and children was performed first. A control group of children was created by matching with anonymous files from local authorities. The results of the children's compulsory health & development assessments were used to compare the two groups. 406 women were included in the study, of whom 6 were expecting twins. The psychomotor development of 412 children was monitored, up to the day 8 assessments in 388 cases, the year 2 assessments in 276 cases, and the year 6 assessments in 232 cases. Sixty children have not yet reached the age of 6 years. No significant differences in psychomotor or height/weight criteria (p > 0.05 for both) were found between the exposed and unexposed children. No malformations were reported. These findings support the use of HBO therapy for all expectant mothers exposed to CO poisoning. No specific follow-up of the children is necessary if their neonatal status is normal.

Controversial issues in hyperbaric oxygen therapy: a European Committee for Hyperbaric Medicine Workshop.

Every few years, the European Committee for Hyperbaric Medicine (ECHM) publishes its recommendations concerning the clinical indications for hyperbaric oxygen therapy (HBOT). The last recommendations were issued during the 7th European Consensus Conference on Hyperbaric Medicine in 2004. Since then, several publications have reported on the use of HBOT in some indications in which it has not yet been recommended routinely, namely aseptic bone necrosis, global brain ischaemia and autism. Patients or their families push physicians and staff of hyperbaric facilities to use hyperbaric treatment regardless of the quality of the scientific evidence. Therefore, the ECHM Workshop "Controversial issues in hyperbaric oxygen therapy" was convened as a satellite meeting of the 2010 European Underwater and Baromedical Society Annual Scientific Meeting in Istanbul, Turkey in 2010. For each topic, a set procedure was used: first came a general report by specialists in the topic, incorporating a review of current pathophysiological, experimental and clinical evidence. Then, there were reports from hyperbaric facilities that had gained clinical experience in that condition, followed by a general discussion with specialists present in the audience. Finally, statements regarding each topic were proposed and voted on by the audience and these were presented to the ECHM Executive Board for consideration and possible approval. In conclusion, the use of HBOT in femoral head necrosis will be proposed during the next ECHM Consensus Conference to become an 'accepted' indication; whilst the use of HBOT in global brain ischaemia and autism should retain its current ECHM recommendations, that it should be 'optional' and 'non-accepted' respectively.

Postoperative ischemic bronchitis after lymph node dissection and primary lung cancer resection.

BACKGROUND: The purpose of this study was to determine the incidence and symptoms of postoperative ischemic bronchitis (POIB) after systematic lymph node dissection (LND) and evaluate the effect of hyperbaric oxygen therapy in patients with primary lung cancer. METHODS: From January 2004 to December 2009, 1,071 patients underwent a standard resection for non-small cell lung cancer and radical systematic lymph node dissection. Fiberoptic bronchoscopy was performed systematically between days 7 and 12. We analyzed the clinical and biologic signs of POIB. Once the diagnosis established a treatment by hyperbaric oxygen, therapy was undertaken. RESULTS: A POIB was observed in 34 patients (3.21%) (2 women and 32 men). Mean age was 59 ± 10 years (range, 25 to 79 years). A POIB occurred within 8 ± 3 days; after right pulmonary resection (n = 21; 62%) and after left resection (n = 13; 38%). A POIB appeared asymptomatically for 27 patients (80%), whereas only 7 patients (20%) presented with fever and hyperleukocytosis. Their localization were bronchial stumps (n = 21; 62%), homolateral bronchial tree (n = 11; 32%), or extension toward the contralateral bronchial tree (n = 2; 6%). The mean number of hyperbaric oxygen therapy sessions was 14 (1 to 48). A POIB worsening was observed in 6 patients (18%), requiring a surgical rescue therapy. CONCLUSIONS: The clinical presentation of POIB is poor and systematic fiberoptic bronchoscopy should be performed, especially in patients with a high risk of bronchopleural fistula. Hyperbaric oxygen therapy in the management of ischemic bronchitis may be a promising adjunctive treatment.

Acute delirium in a critically ill patient may be a wolf in sheep's clothing.

Acute delirium is a commonly encountered problem in the intensive care unit (ICU), which has a myriad of causes and contributes to poor outcomes. We present the case of an alcoholic critically ill patient who developed prolonged acute ICU delirium wrongly diagnosed as sedation and alcohol withdrawal. Protracted vomiting, swallowing disorders and continuous aspirations prevented him from enteral feeding and discontinuation of mechanical ventilation. After several days, it became clear that the patient had been misdiagnosed. Fortunately, nystagmus and ophthalmoplegia then allowed the recognition of Wernicke's encephalopathy, confirmed by cerebral MRIs. After thiamine supplementation, his state improved but he was discharged only on day 32. Wernicke's encephalopathy is an acute reversible neuropsychiatric emergency, which is falsely considered as uncommon, and is largely misdiagnosed, especially in critically ill patients. Thiamine should be systematically given to all critically ill alcoholic patients, especially those with protracted vomiting.

A review of the clinical significance of tissue hypoxia measurements in lower extremity wound management.

The aim of this paper is to review techniques that are currently available to measure tissue hypoxia in order to benefit the management of wounds. Direct measurement of tissue partial oxygen pressure (PO(2)) is invasive and therefore unappealing in clinical practice. Several techniques (PET scans, MRI derived techniques) are primarily applicable to research rather than clinical applications. Imaging techniques (duplex ultrasonography, arteriography, MRI techniques) are recommended only as part of the workup for revascularisation. Techniques that assess local perfusion include clearance methods, transcutaneous O(2) and CO( 2) pressure measurement, and laser Doppler flowmetry and imaging. These techniques permit interpretation of altered perfusion states. Each technique offers subtly different information concerning microvascular function. All these techniques require strict protocols to derive reliable data. The potential of the promising near infrared reflectance spectroscopy (NIRS) technique is yet to be determined.

Oxygen therapy for CO poisoning: rationale and recommendations.

CO poisoning remains a serious public health problem. Oxygen is the basis of its treatment and HBO has been proven more effective to prevent cognitive sequelae than NBO. Most commonly accepted criteria for HBO treatment are: comatose patient, loss of consciousness, neuropsychological and cardiac symptoms and pregnancy. However, patients not requiring HBO, have to be treated by a correct NBO regimen.

[Oxygen and wound healing]. / Oxygène et processus de cicatrisation.

It has long been recognized that normal healing is dependent on the oxygen gradient in the wound Hypoxia can slow or arrest the healing process and augments the risk of infection. While hypoxia triggers neoangiogenesis, normal tissue oxygen pressures are mandatory for migration of repair cells (macrophages, fibroblasts), production of collagen precursors and, thus, for wound repair with good mechanical properties. Recent studies have identified the underlying molecular mechanisms of wound repair. In clinical practice, hyperbaric oxygen therapy is to treat problem wounds like diabetic foot lesions, arterial ulcers, and radionecrosis. Direct or indirect measurement of oxygen tissue pressure can help to select patients and to monitor treatment outcome.

Hyperbaric oxygen therapy in the treatment of radio-induced lesions in normal tissues: a literature review.

Late complications are one of the major factors limiting radiotherapy treatment, and their treatment is not codified. Hyperbaric oxygen (HBO) has been used in combination with radiotherapy for over half a century, either to maximise its effectiveness or in an attempt to treat late complications. In this latter case, retrospective trials and case reports are prevailing in literature. This prompted European Society for Therapeutic Radiotherapy and Oncology and European Committee for Hyperbaric Medicine to organise a consensus conference in October 2001, dealing with the HBO indications on radiotherapy for the treatment and prevention of late complications. This updated literature review is part of the documents the jury based its opinion on. A systematic search was done on literature from 1960 to 2004, by only taking into account the articles that appeared in peer review journals. Hyperbaric oxygen treatment involving complications to the head and neck, pelvis and nervous system, and the prevention of complications after surgery in irradiated tissues have been studied. Despite the small number of controlled trials, it may be indicated for the treatment of mandibular osteoradionecrosis in combination with surgery, haemorrhagic cystitis resistant to conventional treatments and the prevention of osteoradionecrosis after dental extraction, whose level of evidence seems to be the most significant though randomised trials are still necessary. The other treatment methods are also outlined for each location.