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SCUBA diving poses risks due to pressure changes during descent (compression) and ascent (decompression). Decompression sickness (DCS) occurs due to gas bubble formation as the pressure decreases, causing joint pain, numbness, dizziness, or even paralysis and death. Immediate treatment involves 100% oxygen to help eliminate inert gases and hyperbaric oxygen therapy (HBOT), which is essential to reduce gas emboli formation and inflammation, thus improving symptoms. We evaluated oxy-inflammation biomarkers in the saliva and urine of nine subjects pre- and post-technical dive on the Haven wreck (GE, Italy). A case of DCS occurred during the dive. The injured diver was treated immediately with O2 and transported to the hyperbaric center of "ASST Ospedale Ca Granda" in Milan. He was treated following the U.S. Navy Treatment Table 5 at 2.8 ATA and the day after with Table 15 at 2.4 ATA. Venous blood and urine samples were collected before and after each HBO treatment. Our study shows that dive increased oxy-inflammation biomarkers (ROS +126%; lipid peroxidation +23%; interleukins-6 +81%, -1β +19%, and TNFα +84%) and nitric oxide metabolites levels (+36%). HBOT after a DCS episode reduced oxidative stress, lowering the very high marker of lipid peroxidation (8-iso-PGF2α), and inhibited inflammatory interleukins. Overall, HBOT improved physiological responses in the diver affected by DCS. [ABSTRACT FROM AUTHOR]

Arterial gas embolism following pulmonary barotrauma occurs in 13–24% of cases of diving deaths. The study aimed to evaluate the usefulness of a histomorphometric digital analysis in the detection of air space over-distension due to pulmonary barotrauma. The study was performed on lung parenchyma specimens of 12 divers: six had died due to arterial gas embolism following pulmonary barotrauma (mean age at death of 54 years, range of 41–61 years), and six had drowned in saltwater without a diagnosis of pulmonary barotrauma (mean age at death of 54 years, range of 41–66 years) (positive controls). For negative controls, six cases of non-SCUBA divers (mean age of death of 42 years, range of 23–55 years) who died of intracerebral haemorrhage were evaluated. No significant differences were observed in the characteristics of the air spaces between control groups (positive and negative). However, differences were observed in the area occupied by air spaces and the percentage of air space area when we compared the case group to the controls (p < 0.01); and there was a slight difference in the maximum and minimum diameters of air space (p < 0.05). The mean area occupied by air spaces and the mean percentage of air space were the most useful for discriminating pulmonary barotrauma from other causes of death (100% sensitivity and 91.7% specificity). Based on our study, inclusion of an increased pattern of air spaces as a possible diagnostic criterion for pulmonary barotrauma would be useful in discerning the cause of diving death. [ABSTRACT FROM AUTHOR]

Pulmonary physiology is significantly altered during underwater exposure, as immersion of the body and increased ambient pressure elicit profound effects on both the cardiovascular and respiratory systems. Thoracic blood pooling, increased breathing gas pressures, and variations in gas volumes alongside ambient pressure changes put the heart and lungs under stress. Normal physiologic function and fitness of the cardiovascular and respiratory systems are prerequisites to safely cope with the challenges of the underwater environment when freediving, or diving with underwater breathing apparatus. Few physicians are trained to understand the physiology and medicine of diving and how to recognize or manage diving injuries. This article provides an overview of the physiologic challenges to the respiratory system during diving, with or without breathing apparatus, and outlines possible health risks and hazards unique to the underwater environment. The underlying pathologic mechanisms of dive-related injuries are reviewed, with an emphasis on pulmonary physiology and pathophysiology. [ABSTRACT FROM AUTHOR]

Objective: Cerebrovascular autoregulation impairment has been associated with stroke risk in cardiac surgery. We hypothesized that greater arterial emboli exposure in open-chamber surgery might promote dysautoreguation. Methods: Forty patients underwent closed or open-chamber surgery. Transcranial Doppler detected emboli and measured bilateral middle cerebral artery flow velocities. Cerebral autoregulation was assessed by averaging the mean velocity index ("Mx," a continuous moving correlation between cerebral blood flow velocity and mean arterial pressure) over 30 min before and after aortic cross-clamp removal. Results: Median (interquartile range) emboli counts were 775 (415, 1211) and 2664 (793, 3734) in the closed-chamber and open-chamber groups. Most appeared after the removal of the aortic cross-clamp (open-chamber 1631 (606, 2296)), (closed-chamber 229 (142, 384)), with emphasis on the right hemisphere (open-chamber: 826 (371, 1622)), (closed-chamber 181 (66, 276)). Linear mixed model analyses of mean velocity index change showed no significant overall effect of group (0.08, 95% CI: −0.04, 0.21; p = 0.19) or side (0.01, 95% CI: −0.03, 0.05; p = 0.74). There was an interaction between group and side (p = 0.001), manifesting as a greater increase in mean velocity index in the right hemisphere in the open than the closed group (mean difference: 0.15, 95% CI: 0.02, 0.27; p = 0.03). Conclusions: Overall, change in mean velocity index before and after cross-clamp removal did not differ between groups. However, most emboli entered the right cerebral hemisphere where this change was significantly greater in the open-chamber group, suggesting a possible association between embolic exposure and dysautoregulation. [ABSTRACT FROM AUTHOR]

For the purposes of this guideline, a diving accident is defined as an event that is either potentially life-threatening or hazardous to health as a result of a reduction in ambient pressure while diving or in other hyperbaric atmospheres with and without diving equipment. This national consensus-based guideline (development grade S2k) presents the current state of knowledge and recommendations on the diagnosis and treatment of diving accident victims. The treatment of a breath-hold diver as well as children and adolescents does not differ in principle. In this regard only unusual tiredness and itching without visible skin changes are mild symptoms. The key action statements: on-site 100% oxygen first aid treatment, immobilization/no unnecessary movement, fluid administration and telephone consultation with a diving medicine specialist are recomme nd ed. Hyperbaric oxygen therapy (HBOT) remains unchanged as the established treatment in severe cases, as there are no therapeutic alternatives. The basic treatment scheme recommended for diving accidents is hyperbaric oxygenation at 280 kPa. [ABSTRACT FROM AUTHOR]

Decompression illness in breath‐hold diving is a rare dysbaric disease mainly characterized by stroke‐like neurological disorders. The early use of DWI‐MRI combined with ADC map in suspected cases can help in the early diagnosis and treatment. [ABSTRACT FROM AUTHOR]

Background: Arterial gas embolus (AGE) is a rare complication of esophagoduodenoscopy (EGD) that has been described in only a few case reports in the literature. The exact etiology remains unknown, but many of the cases share some common characteristics.Case Report: We report the case of a 52-year-old otherwise healthy man who underwent outpatient EGD for a sensation of retained food in his esophagus. During the procedure, he suffered a tonic-clonic seizure, bradycardia, and hypoxia. Subsequent emergency department workup showed pneumocephalus on computed tomography brain imaging, and he was diagnosed with a cerebral AGE (CAGE). He was transferred to our facility for treatment of CAGE with hyperbaric oxygen therapy (HBOT). After multiple hyperbaric treatments, he was discharged with a residual left hemiparesis, which represented a significant improvement in his overall neurologic status. We also present a review of similar EGD CAGE cases from the literature and discuss their outcomes and the need for HBOT. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: Although CAGE from EGD is rare, these patients will often be transferred to the ED from gastrointestinal procedural suites and an emergency physician should understand that an iatrogenic CAGE can result from this procedure and that CAGE is a clinical diagnosis. Definitive care at a critical care-capable hyperbaric chamber will provide the patient with the best chance of meaningful recovery, and transport should be arranged as expeditiously as possible. [ABSTRACT FROM AUTHOR]

Iatrogenic arterial gas embolism (AGE) can be life-threatening. The only causal treatment is immediate hyperbaric oxygen therapy (HBOT). This article reports on a case of a 74-year-old male patient who underwent computed tomography (CT)-guided lung biopsy of suspect nodules after squamous cell carcinoma of the tonsils. During puncture, sudden cardiovascular arrest occurred. The CT scan documented severe arterial gas embolism in the aorta, spinal canal, left heart ventricle, and brain. The patient was then transferred to our hospital for HBOT. After the first HBOT, an additional CT scan showed regression of all gas inclusions. In the treatment of gas embolism, HBOT is considered the gold standard and is indispensable. It is primarily used to reduce acute bubble effects and to avoid secondary bubble effects. Unfortunately, the long persisting gas occlusions and perfusion deficits led to severe hypoxic brain damage and a poor prognosis for the patient. In this case report we present the management of (iatrogenic) arterial gas embolism and point out the necessity of immediate HBOT. Furthermore, we discuss the pathophysiology leading to arterial gas embolism on the basis of the gas laws. [ABSTRACT FROM AUTHOR]

The purpose of this study was to suggest modifications of autopsy techniques in order to improve post-mortem diagnosis of arterial gas embolism (AGE) based on multidisciplinary investigation of SCUBA diving fatalities. Five adult human cadavers from the voluntary donation program of the Human Anatomy Laboratory, and eight judicial autopsied bodies of SCUBA divers from the Forensic Pathology Service were assessed. Before performing any autopsies, we accessed the diving plan and the divers' profiles for each case. We then introduced a new dissection procedure that included identification, isolation, and manipulation of carotid, vertebral and thoracic arterial systems. The dissected vascular structures that allowed optimall isolation of the systemic arterial circulation were identified and ligated. In three of the eight judicial cases, we had a strongly suggestive history of arterial gas embolism following pulmonary barotrauma (PBt/AGE). In these cases, the additional arterial dissection allowed us to clearly diagnose AGE in one of them. The autopsy of the rest of the cases showed other causes of death such as asphyxia by drowning and heart attack. In all cases we were able to reject decompression sickness, and in some of them we showed the presence of artefacts secondary to decomposition and resuscitation maneuvers. These results allow us to suggest a specific autopsy technique divided into four steps, aimed at confirming or excluding some evidence of dysbaric disorders according to a re-enactment of the incident. We have demonstrated the presence of large volumes of intravascular air, which is typical of PBt/AGE. [ABSTRACT FROM AUTHOR]

While ectopic gas can be a sign of dangerous disease requiring immediate medical or surgical intervention, it can also be an incidental and benign finding. Intravenous gas and spinal vacuum gas are common and almost always benign. Intravascular gas is most often related to instrumentation and, if intraarticular, can cause end-organ ischemia; however, treatment is usually supportive. Pneumocephalus arises from a communication with paranasal sinuses or mastoids more often than from meningeal infection and can usually be managed nonoperatively. In part 3 of this series, the different causes of ectopic gas in the vessels, skull, and spine are reviewed, as are the imaging features that can help to narrow the differential diagnosis. [ABSTRACT FROM AUTHOR]

Diving is a popular activity, largely practiced worldwide. Diving fatalities are not rare events, with drowning being the most common cause of death, followed by cardiac-related natural causes, immersion pulmonary edema and arterial gas embolism. In such cases, positive signs of drowning are not specific, depending also on the time of submersion of corpses. Moreover, drowning can be the terminal event. Over the years, measures to perform appropriate post-mortem examination in cases of diving fatalities were suggested, including the execution of post-mortem CT-scan, the use of a decompression chamber and the adoption of specific autoptic techniques. Although a multidisciplinary approach in forensic investigations concerning diving fatalities is discussed, poor cases focus on how the analysis of diving computer records and equipment can contribute to determining the cause of death. The present study shows how the cooperation between a forensic underwater expert and a forensic pathologist played a crucial role in interpreting radiological findings, guiding the autopsy and confirming/denying circumstantial data emerging from the investigations. Technical analysis of dive computer records and diving equipment is a fundamental step in the definition of the cause of death in diving fatalities. All diving computer data, not only those related to maximum depth and ascent's profile, should be considered in detail, and the immersion graph carefully studied by both the forensic pathologist and the forensic underwater experts. The diving technical data can often play a crucial role in explaining any legal issue related to the circumstances of death, possibly leading the prosecutor to further investigation. • Diving fatalities are not rare events. • In those cases, autoptic diagnosis can be challenging. • PMCT-scan can steer the forensic pathologist to perform a proper examination. • Forensic underwater experts have a pivotal role in diving fatalities. • Technical analysis of dive computer records and equipment are fundamental. [ABSTRACT FROM AUTHOR]

In recent years, hyperbaric oxygen (HBO) has been used in the treatment of a lot of diseases such as decompression sickness, arterial gas embolism, carbon dioxide poisoning, soft tissue infection, refractory osteomyelitis, and problematic wound, but little is known about its application in liver transplantation. Although several studies have been conducted to investigate the protective effects of HBO on liver transplantation and liver preservation, there are still some controversies on this issue, especially its immunomodulatory effect. In this short review, we briefly summarize the findings supporting the application of HBO during liver transplantation (including donors and recipients). [ABSTRACT FROM AUTHOR]

Background: Postpartum haemorrhage (PPH) is an unpredictable obstetric emergency that requires a multidisciplinary approach. Pelvic arterial embolization (PAE) is considered as a second-line treatment, although the published results have not been reviewed systematically since 2007.Objectives: To evaluate success and complication rates of PAE to treat PPH in the study hospital between 2009 and 2015, and to perform a systematic review of the literature on the reported efficacy and safety of PAE for the management of PPH.Search Strategy: A systematic review of articles on PAE in English or Spanish was conducted using Medline and the Cochrane Library.Selection Criteria: All published articles assessing success and complication rates of PAE in cases of PPH. The search was restricted to articles published in English or Spanish between 2000 and 2015, with at least 25 cases.Data Collection and Analysis: Obstetric variables, maternal haemodynamic state, pre-/postembolization management, technique-related variables, post-PAE evolution and complications were recorded in the case series study. Study characteristics, success rates and PAE-related complication rates were recorded in the systematic review.Main Results: The case series included 29 patients. The majority of these patients were primiparous, with singleton term pregnancies and spontaneous labour. Caesarean section was performed in 62.1% of patients undergoing PAE for PPH. PAE was successful in 89.6% [95% confidence interval (CI) 78.3-100] of cases. Twenty studies were included in the systematic review, providing data from 1739 patients. PAE was successful in 89.4% (95% CI 87.9-90.9) of cases. The mortality rate was 0.9%, and other major complications were uncommon (1.8%).Conclusions: PAE was found to be a minimally invasive, highly successful and safe technique for the management of PPH. It should be considered in PPH refractory to initial treatment. [ABSTRACT FROM AUTHOR]

We propose arterial pCO2 as test to discover vascular access recirculation (VAR) in bicarbonate hemodialysis (HD). We selected 30 HD patients with a ascertained well-functioning arteriovenous fistula (Control). In these patients, we artificially created VAR through the reversion of HD lines (Reversed). Results of the arterial gas analysis were collected at the start of HD (baseline) and after 5 min. At baseline, no differences of pH, pCO2 and HCO3 were found between the 2 groups. At 5 min, pCO2 increased from 38.1 ± 3.3 to 47.2 ± 6.3 mm Hg (p < 0.0001) in Reversed, whereas no increase was found in Control (p = 0.052). Areas under curve of pCO2 -increase was 0.96 (0.91-1.00) and pCO2 at 5 min 0.92 (0.85- 0.98). pCO2 -increase >4.5 mm Hg showed sensitivity 86.7% and specificity 100% with positive predictive value (PPV) 100% and negative predictive value (NPV) 89%. A pCO2 value above 43 mm Hg at 5 min showed sensitivity 80%, specificity 90%, PPV 89%, NPV 82%. pCO2 increase >4.5 mm Hg and/ or pCO2 at 5 min >43 mm Hg may accurately detect VAR. [ABSTRACT FROM AUTHOR]

Background: Arterial gas embolism (AGE) is a major cause of morbidity and mortality in self-contained underwater breathing apparatus (SCUBA) diving and certain medical procedures. There are currently no well-defined criteria to diagnose AGE. Emergency physicians often find themselves facing a decision whether or not a patient with dive-related symptoms has an AGE and needs to be transferred to a hyperbaric facility.Objectives: The objective of this study was to test the accuracy of diagnostic criteria developed by the San Diego Hyperbaric Oxygen Group (SANDHOG) for the diagnosis of AGE.Methods: This was a retrospective review of consultations completed by the Hyperbaric Medicine Department (HBO) at the University of California San Diego where the diagnosis of AGE was considered. HBO staff blinded to the purpose of the study identified potential cases of AGE. The criterion standard was the final diagnosis by a panel of HBO specialists also blinded to the purpose of this study. Descriptive statistics and comparisons evaluating SANDHOG criteria compared to the criterion standard were performed.Results: Twenty-six patients were identified for inclusion. Twenty-three of 26 (88%) were SCUBA divers, 2 had intravascular gas injections, and 1 patient had a military training chamber accident. Nineteen of 26 (73%) patients were diagnosed with AGE. A SANDHOG score of 2 had 94.7% sensitivity (95% confidence interval [CI] 71.9-99.7), 85.7% specificity (95% CI 42.0-99.2), positive likelihood ratio of 6.6 (95% CI 1.1-40.8), and negative likelihood ratio of 0.06 (95% CI 0.01-0.43) for AGE. A SANDHOG score <2 had a negative predictive value of 100% for AGE.Conclusion: The SANDHOG criteria appear to be reliable in diagnosing AGE. AGE is unlikely with SANDHOG scores <2, whereas SANDHOG scores ≥2 resulted in high sensitivity and specificity for AGE. Emergency physicians may find this tool useful in evaluating patients for suspected AGE, and it may assist in determining whether to transfer the patient to a hyperbaric facility. Future studies should be performed to further examine and validate the accuracy and inter-rater reliability of this tool. [ABSTRACT FROM AUTHOR]

Purpose: Surgical revascularization for pediatric moyamoya disease improves cerebral blood flow (CBF) and consequently may prevent further ischemic events. However, the timing of the treatment is controversial especially for patients with no ischemic symptom and normal CBF. The purpose of this case report is to inform and infer the surgical treatment timing for pediatric moyamoya disease patients. Case report: A 10-year-old female patient with unilateral moyamoya disease complaining of only headache as a symptom and whose Suzuki stage was II or in transition to III by angiography and CBF was almost normal was admitted to Tokyo Women's Medical University Hospital. We performed superficial temporal artery-middle cerebral artery (STA-MCA) double anastomoses for the patient because we estimated her headache was derived from low perfusion in the brain. STA-MCA bypass surgery was not only effective for relief of her severe headache but also valid for her cerebral perfusion. Her angiography showed much supply from external carotid artery to intracranial arteries via bypass grafts in 7 months. Conclusion: Our case showed early surgical treatment was beneficial for relief of severe headache even for early staged pediatric moyamoya disease patients by improving perfusion pressure and cerebral circulation. [ABSTRACT FROM AUTHOR]

Background:Knowledge on factors associated with mortality can help identify patients with COPD that might benefit from close monitoring and intervention. Arterial blood gases (ABGs) are related to mortality, but both arterial tension of oxygen (PaO2) and arterial tension of carbon dioxide (PaCO2) vary over time. The aim of our study was to investigate the association between repeatedly measured ABGs and mortality in men and women with COPD.Methods:A cohort of 419 Norwegian subjects with COPD, GOLD stage II-IV, aged 40–75, was followed up with up to seven ABGs, measured during stable phase for three years. Cox proportional hazard models were used to quantify the relationship between both single and repeatedly measured ABGs and all-cause mortality after five years, adjusting for age, sex, and the updated BODE index.Results:A total of 64 subjects died during follow-up. Mean initial arterial oxygen tension (standard deviation) was significantly higher in survivors compared to deceased, with PaO2(in kPa) 9.4 (1.1) versus 8.8 (1.2), p<0.001. Corresponding numbers for PaCO2were 5.3 (0.5) and 5.5 (0.7),p< 0.001. In analyses adjusting for age, sex, and the updated BODE index hazard ratios – HR(95% confidence intervals) - for all-cause mortality were 0.73 (0.55, 0.97) and 1.58 (0.90, 2.76) for repeated measures of PaO2and PaCO2, respectively.Conclusion:Both arterial oxygen and carbon dioxide tension were related to mortality in this study, and arterial oxygen tension added prognostic information to the updated BODE index in COPD. [ABSTRACT FROM PUBLISHER]

The article presents several case studies including one of a 77-year-old female, a middle aged recipient and 27-year-old diver. As mentioned, these people were admitted to hospital after being treated for renal failure, cardiac arrest because of diseased kidney transplant and acute kidney injury caused by arterial gas emboli formation.

Abstract: Background: Arterial gas embolism (AGE) is a clinical problem that occurs directly in cardiopulmonary bypass machines in open-heart surgeries, or indirectly (through cardiac or pulmonary right to left shunts) in dive accidents, resulting in serious morbidity and even death. Perfluorocarbon (PFC) emulsions have been used for the treatment of AGE in an animal model. We hypothesized that PFC emulsions enhance microvascular blood flow, speed bubble resolution, and oxygenation in AGE compared with saline in a model of cremaster muscle from anesthetized rats. Materials and methods: AGE was induced by direct air injection into the femoral artery ipsilateral to the studied cremaster muscle. Microhemodynamics, microvascular, and tissue oxygenation were determined before and after treatment with two different commercial PFC emulsions (C10F20, Oxycyte; Oxygen Biotherapeutics, Inc and C10F18, PHER-O2; Sanguine Corporation, Inc) compared with saline in real time using brightfield and phosphorescence microscopy. Results: Blood pressure and heart rate remained unchanged. Systemic PO2, oxygen (O2) content, and glucose were higher in PFC groups, whereas hematocrit dropped in all groups. Arteriolar blood flow went up 85% and 80% of baseline after C10F20 and C10F18 treatments, respectively, versus 11% after saline treatment. Arteriolar and tissue PO2, and O2 delivery were higher in PFC groups compared with the control group. There was an increase in arteriolar blood flow, reduction in diffusional resistance of O2 in the plasma, and improved tissue oxygenation. Conclusions: Administration of PFC emulsions in AGE is superior to saline primarily because of surfactant properties along with air bubble reabsorption. [Copyright &y& Elsevier]

Hemodynamic changes induced by self-contained underwater breathing apparatus diving were investigated using Doppler echocardiography. We detected circulating bubbles in both right and left cavities of the heart and in the cerebral circulation in two divers with a large patent foramen ovale. A reduction in the left ventricular preload was suggested by echocardiographic measurements. The decreased cardiac preload was paralleled to a lower stroke volume and cardiac output. These findings were also observed in divers with no evidence of circulating bubbles. In these subjects, pulmonary vascular resistances remained unchanged while an increase was observed in the two divers with arterial bubbles. This increase could promote right-to-left shunting. [ABSTRACT FROM AUTHOR]

Objective: Differentiation between an occluded and a patent extracranial internal carotid artery (ICA) is crucial in the diagnostic workup of patients with acute ischemic stroke; particularly in patients eligible for endovascular treatment. We report neurological and radiological findings of cases in which CTA in the acute phase incorrectly revealed an occlusion of the ICA. Methods: In our image data base of 54 patients with acute ischemic stroke eligible for endovascular treatment, we searched for patients with an occluded extracranial ICA on CTA whereas DSA proved that this artery was patent. Of these patients, all available images were re-examined to investigate possible causes of these so-called pseudo-occlusions. Results: We detected 6 patients (11%) with a pseudo-occlusion. The pseudo-occlusions on CTA were associated with reduced flow due to carotid T-occlusions (4 cases) or a combination of a high degree stenosis of the extracranial ICA and MCA occlusion (2 cases). Conclusion: CTA in the acute phase of ischemic stroke needs to be interpreted with severe caution, and in endovascular treatment decisions we should be aware that an extracranial ICA occlusion may be a false positive finding. [ABSTRACT FROM AUTHOR]

Highlights: [•] Arterialised-venous blood gases (AVBG) were validated in obesity hypoventilation syndrome. [•] AVBGs agreed closely with arterial bicarbonate and pH in OHS and healthy controls. [•] AVBG-arterial agreement for OHS was equivalent to that of the control group. [•] AVBG-arterial agreement was equivalent between hand, forearm and antecubital veins. [•] AVBG sampling provides valid measures of pH, and bicarbonate in people with OHS. [Copyright &y& Elsevier]

Abstract: Background: Arterial carbon dioxide tension (PaCO2) affects neuronal function and cerebral blood flow. However, its association with outcome in patients admitted to intensive care unit (ICU) after cardiac arrest (CA) has not been evaluated. Methods and results: Observational cohort study using data from the Australian New Zealand (ANZ) Intensive Care Society Adult-Patient-Database (ANZICS-APD). Outcomes analyses were adjusted for illness severity, co-morbidities, hypothermia, treatment limitations, age, year of admission, glucose, source of admission, PaO2 and propensity score. We studied 16,542 consecutive patients admitted to 125 ANZ ICUs after CA between 2000 and 2011. Using the APD-PaCO2 (obtained within 24h of ICU admission), 3010 (18.2%) were classified into the hypo- (PaCO2 <35mmHg), 6705 (40.5%) into the normo- (35–45mmHg) and 6827 (41.3%) into the hypercapnia (>45mmHg) group. The hypocapnia group, compared with the normocapnia group, had a trend toward higher in-hospital mortality (OR 1.12 [95% CI 1.00–1.24, p =0.04]), lower rate of discharge home (OR 0.81 [0.70–0.94, p <0.01]) and higher likelihood of fulfilling composite adverse outcome of death and no discharge home (OR 1.23 [1.10–1.37, p <0.001]). In contrast, the hypercapnia group had similar in-hospital mortality (OR 1.06 [0.97–1.15, p =0.19]) but higher rate of discharge home among survivors (OR 1.16 [1.03–1.32, p =0.01]) and similar likelihood of fulfilling the composite outcome (OR 0.97 [0.89–1.06, p =0.52]). Cox-proportional hazards modelling supported these findings. Conclusions: Hypo- and hypercapnia are common after ICU admission post-CA. Compared with normocapnia, hypocapnia was independently associated with worse clinical outcomes and hypercapnia a greater likelihood of discharge home among survivors. [Copyright &y& Elsevier]

Abstract: Background: Cerebral blood flow and intracranial pressure (ICP) has been known to be increased after graft reperfusion during liver transplantation, which was correlated with arterial carbon dioxide concentration (PaCO2). Ultrasonographic measurement of optic nerve sheath diameter (ONSD) is a simple and noninvasive method for evaluating ICP. We investigated the correlation between ONSD and the PaCO2 during reperfusion in liver transplant recipients. Methods: Twenty liver transplant recipients with end-stage liver disease were enrolled. We measured ONSD and PaCO2 at 6 time points: preinduction, preanhepatic phase, anhepatic phase, 5 minutes after reperfusion, 30 minutes after reperfusion, and neohepatic phase. Pearson correlation analysis and receiver operating characteristics (ROC) curve analysis were performed. Results: ONSD measured 5 minutes after reperfusion was significantly higher compared with the other time points. Differences in ONSD between the anhepatic phase and 5 minutes after reperfusion demonstrated significant correlations with both PaCO2 at the anhepatic phase and 5 minutes after reperfusion (both P < .001). On the ROC curve analysis, PaCO2 of 35 mm Hg at the anhepatic phase could be used to indicate ≥20% changes in ONSD after reperfusion. There were significant increases in ONSD after graft reperfusion in liver transplant recipients with PaCO2 ≥ 35 mm Hg at the anhepatic phase (P = .004). Conclusion: ONSD was increased just after reperfusion, which demonstrated good correlation with PaCO2 during reperfusion in liver transplant recipients. This finding suggests that the carbon dioxide can play a key role in increasing ONSD during hepatic graft reperfusion. [Copyright &y& Elsevier]

Self-oscillations of an intra-pipe inspection pig are investigated. A dynamic model of the machine is formulated, and its motion regimes are analyzed qualitatively. The law governing the motion of the inspection pig and the law governing the velocity variation corresponding to it are derived. [ABSTRACT FROM AUTHOR]

Purpose: The main problem of one-lung ventilation (OLV) is hypoxemia. The use of a high tidal volume for preventing hypoxemia during OLV is controversial. We compared the effects of a high tidal volume versus a low tidal volume with or without PEEP on arterial oxygen tension (PaO) and pulmonary mechanics during OLV. Methods: Sixty patients (age range, 16-65 years; ASA I, II) who underwent wedge resection with video-assisted thoracostomy during OLV were assigned to three groups: group I received a high tidal volume (10 ml/kg) ( n = 20), group II received a low tidal volume (6 ml/kg) ( n = 20), and group III received a low tidal volume (6 ml/kg) with PEEP (5 cmHO) ( n = 20). Patient hemodynamics, pulmonary mechanics, and arterial blood gases were measured before (T) OLV and 5 (T), 15 (T), 30 (T), and 45 min (T) after OLV. Results: The PaO/FiO ratios of group II and III were significantly decreased and the incidence of hypoxemia was significantly higher in groups II and III than in group I ( P < 0.05). Conclusion: During OLV, mechanical ventilation with a low tidal volume with or without PEEP increased hypoxemia as compared to that when performing OLV with a high tidal volume. [ABSTRACT FROM AUTHOR]

Abstract: Cerebral arterial gas embolism is a dreaded complication of diving and invasive medical procedures. Many different animal models have been used in research on cerebral arterial gas embolism. This review provides an overview of the most important characteristics of these animal models. The properties discussed are species, cerebrovascular anatomy, method of air embolization, amount of air, bubble size, outcome parameters, anesthesia, blood glucose, body temperature and blood pressure. [Copyright &y& Elsevier]

Abstract: Objective: Cerebral arterial gas embolism (CAGE) is a serious hazard in cardiovascular surgery and other invasive procedures. We used a swine model of CAGE to determine if quantitative electroencephalography (qEEG) is a useful tool in diagnosis and prognostication of CAGE. Methods: 0.05ml/kg of air was injected into the ascending pharyngeal artery in 16 pigs. Intracranial pressure, lactate in brain microdialysate and brain oxygen tension were measured during 4h after embolization. The qEEG parameters mean amplitude (MAMP), alpha-delta ratio (ADR), spectral edge frequency (SEF90), spatial brain symmetry index (sBSI) and temporal brain symmetry index (tBSI) were calculated. Results: MAMP and tBSI but not ADR, SEF90 and sBSI correlate with intracranial pressure, brain lactate and brain oxygen tension after 4h. Early levels of MAMP and tBSI can predict intracranial pressure, brain lactate and brain oxygen tension after 4h. Conclusions: MAMP and tBSI are sensitive for cerebral injury and can predict outcome in a swine model of CAGE. Significance: This study provides evidence for the utility of qEEG for diagnosis and prognosis in CAGE. Further studies are necessary to investigate the use of this method in patients. [Copyright &y& Elsevier]

Abstract: Cerebral arterial gas embolism is a risk in diving and occurs as a complication in surgery and interventional radiology. Swine models for cerebral arterial gas embolism have been used in the past. However, injection of air into the main artery feeding the pig brain – the ascending pharyngeal artery – might be complicated by the presence of the carotid rete, an arteriolar network at the base of the brain. On the other hand, anastomoses between external and internal carotid territories are present in the pig. In order to determine the most appropriate vessel for air injection, we performed experiments in which air was injected into either the ascending pharyngeal artery or the external carotid artery. We injected 0.25ml/kg of room air selectively into the ascending pharyngeal artery or the external carotid artery of 35–40kg Landrace pigs (n =8). We assessed the effect on cerebral metabolism by measuring intracranial pressure, brain oxygen tension and brain glucose and lactate concentrations using cerebral microdialysis. Intracranial pressure and brain oxygen tension changed significantly in both groups, but did not differ between groups. Brain lactate increased significantly more in pigs in which air was injected into the ascending pharyngeal artery. Intracranial pressure, brain oxygen tension and brain lactate correlated after injection of air into the ascending pharyngeal artery, but not after injection into the external carotid artery. Our model is suitable for investigation of cerebral arterial gas embolism. The ascending pharyngeal artery is the most appropriate vessel for air injection. [ABSTRACT FROM AUTHOR]

The article offers information decompression illness. The cause of decompression illness is the formation of intravascular or extravascular bubbles in blood or tissue resulting from a reduction in environmental pressure. Its two pathophysiological syndromes are arterial gas embolism and the common decompression sickness. Its diagnosis is made on a clinical basis. Possible symptoms include altered consciousness, confusion or seizure. They can occur in divers, compressed air workers, aviators and astronauts.

The prevalence of Patent Foramen Ovale (PFO) is an increasing risk factor for paradoxical cerebral embolism. Decompression Sickness (DCS) results from gas coming out of solution in the bodily fluids and tissues when a diver ascends too quickly. This occurs because decreasing pressure lowers the solubility of gas in liquid. Also, the expansion of gas in the lungs may lead to alveolar rupture which may, in turn, result in Arterial Gas Embolism (AGE). The amount of nitrogen that diffuses into the bodily tissues during a dive depends on the depth of the dive and the duration of exposure. PFO acquires significance in various congenital heart diseases leading to right to left shunt and thus to paradoxical embolism. The presence of asymptomatic brain lesion like "spots" has been investigated in a randomized population of diving individuals. The partial pressure of the gas can be calculated by Henry's Law and the pressure of the blood stream can be calculated by Poiseuille's Law. The statistical comparison of the fractal dimension was obtained by means of Box Counting Method with slope analysis. We observe that PFO plays a significant role in the occurrence of unexplained cerebral DCS and white spots in the brain. [ABSTRACT FROM AUTHOR]

The interest in measuring physiological parameters (especially arterial blood gases) has grown progressively in parallel to the development of new technologies. Physiological parameters were first measured invasively and at discrete time points; however, it was clearly desirable to measure them continuously and non-invasively. The development of intensive care units promoted the use of ventilators via oral intubation ventilators via oral intubation and mechanical respiratory variables were progressively studied. Later, the knowledge gained in the hospital was applied to out-of-hospital management. In the present paper we review the invasive and non-invasive techniques for monitoring respiratory variables. [ABSTRACT FROM AUTHOR]

It has been stated that the interior of the right ventricle is as unique to each individual as one's fingerprint. This statement is backed by numerous publications which demonstrates considerable variation in the number, shape and configuration of papillary muscles inside the normal right ventricle. It has also been shown that these variants may be the cause of cardiac rhythm disorders. In this case report another potential complication of such right ventricular papillary muscle variants is proposed-these muscles may be the source of pulmonary emboli. The pathogenesis may be that of local stasis around these aberrant muscular structures and/or emboli may form inside the right ventricle as a result of cardiac rhythm disorders, induced by these muscles. It is proposed that in future the role of the right ventricle as the source of pulmonary emboli will become more apparent and an important part of the diagnostic work up in cases of idiopathic pulmonary embolism. [ABSTRACT FROM AUTHOR]

The article presents a case series and a literature review on hyperbaric oxygen therapy in the treatment of post cardiac surgical stroke cases in the Christchurch Hospital in New Zealand. The average age of five males and seven males in the series is 67 years. Among the risk factors for the development of post-cardiac surgical strokes are age, hypertension and diabetes. Results show iatrogenic cerebral arterial gas embolism (CAGE) is a rare complication of invasive medical procedures.

The article presents two case studies on the development of cerebral air emboli during micrographic surgery. It categorizes gas emboli into two groups including venous emboli and arteri emboli. It states that the symptoms of gas embolism depend on whether the emboli enter the venous or arterial systems. It suggests that scalp surgery is a safe method due of the separation of the intraosseous diploic venous system from the extracranial soft tissue venous drainage system of the scalp.

Abstract: Aim: To compare systemic fat extravasation in unreamed and experimentally reamed nailing. Methods: An osteotomy was created in the proximal third of the femoral shaft in 16 sheep, and intramedullary pressure increase and fat extravasation were monitored for the two nailing techniques. Results: The highest intramedullary pressures, median 2700mmHg, and highest percentages of fat extravasation, peaking at almost 90% of fat, were found for the unreamed nailing technique. The values for the reamed group were significantly lower. Conclusions: The extravasation of intramedullary fat can be attributed to the great increase in intramedullary pressure that occurs during unreamed nailing. Correctly performed intramedullary reaming with the new reaming system produces lower pressures and much less systemic fat extravasation, reducing the risk for fat embolism. [Copyright &y& Elsevier]

Systemic air embolism in neonates, either premature or full term, necessitating mechanical ventilation is a devastating and usually fatal condition. We describe three cases of this complication, two in mechanically assisted preterm babies, and one in a full-term dysmorphic patient. Causes and possible management are described. [ABSTRACT FROM AUTHOR]

Intravascular gas embolism may occur with decompression in space flight, as well as during cardiac and vascular surgery. Intravascular bubbles may be deposited into any end organ, such as the heart or the brain. Surface interactions between the bubble and the endothelial cells lining the vasculature result in serious impairment of blood flow and can lead to heart attack, stroke, or even death. To develop effective therapeutic strategies, there is a need for understanding the dynamics of bubble motion through blood and its interaction with the vessel wall through which it moves. Toward this goal, we numerically investigate the axisymmetric motion of a bubble moving through a vertical circular tube in a shear-thinning generalized power-law fluid, using a front-tracking method. The formulation is characterized by the inlet Reynolds number, capillary number, Weber number, and Froude number. The flow dynamics and the associated wall shear stresses are documented for a combination of two different inlet flow conditions (inlet Reynolds numbers) and three different effective bubble radii (ratio of the undeformed bubble radii to the tube radii). The results of the non-Newtonian model are then compared with that of the model assuming a Newtonian blood viscosity. Specifically, for an almost occluding bubble (effective bubble radius = 0.9), the wall shear stress and the bubble residence time are compared for both Newtonian and non-Newtonian cases. Results show that at low shear rates, for a given pressure gradient the residence time for a non-Newtonian flow is higher than that for a Newtonian flow. [ABSTRACT FROM AUTHOR]

Background: Nonaspirin, nonsteroidal anti-inflammatory drugs (NANSAIDs) have been associated with arterial thromboembolic events in the general population. Our objective was to determine the prevalence of NANSAID use in patients diagnosed with cryptogenic emboli or paradoxical embolic events from a patent foramen ovale (PFO) or atrial septal defect (ASD) compared with a control population with an incidental PFO/ASD and no history of embolic events. Methods: We performed a retrospective case-control study of 90 age-matched patients to assess the association of NANSAIDs with cryptogenic arterial embolic events in patients with and without a history of PFO/ASD. Odds ratios (ORs) were obtained by χ2 analysis. Multivariate analysis was conducted with a logistical regression method. Results: Patients with cryptogenic embolic events had a high prevalence of prescription NANSAID use regardless of the presence of a PFO/ASD and were far more likely to have a history of NANSAID use than those with an incidentally discovered PFO/ASD and no history of arterial emboli (OR 4.30, 95% confidence interval 1.14–13.07, p = 0.01). Conclusions: Many patients previously diagnosed with paradoxical emboli may be experiencing the prothrombotic effects of NANSAIDs rather than a paradoxical mechanism for their arterial embolic event. Copyright © 2008 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]

An interview with U.S. director Oliver Stone is presented. When asked about why the U.S. diplomacy and the American media have reacted with hostility over his documentary "South of the Border," he thinks that it comes from the old imperial impulse of the U.S. toward Latin America going back to the Monroe Doctrine. He mentions that U.S. remains hostile to anyone who thinks the resources of a country belong to its people. He remarks that today's inflation affects most the middle class.

Abstract   Background and Aims It is a commonly held notion that patients with cirrhosis do not suffer from deep vein thrombosis (DVT) or pulmonary embolism (PE) because they are naturally anticoagulated. However, to date, no studies have been carried out that objectively address this issue. We conducted a study to examine the relationship between cirrhosis and DVT/PE events. Methods A case–control study of patients seen at a tertiary care hospital was performed. Cases were hospitalized patients with biopsy and/or imaging plus clinical evidence of cirrhosis. Well-matched patients with no known evidence of cirrhosis served as controls. The DVT/PE events were identified by the international classification of disease-9 (ICD-9) codes and confirmed with radiographic/nuclear imaging. The Charlson Index was calculated to determine the comorbidity. The incidence of DVT/PE in cirrhotic patients was also compared to patients with chronic kidney disease (CKD), congestive heart failure (CHF), and solid organ cancers. Results This study consisted of 963 cirrhotics and 12,405 controls. Both the incidence of DVT/PE (1.8 vs. 0.9%, P = 0.007) and Charlson Index scores (3.2 ± 1.8 vs. 0.9 ± 1.5, P P = 0.06]. Partial thromboplastin time (PTT; OR 0.88, P = 0.04) and serum albumin (OR 0.47, P = 0.03) were the independent predictors of DVT/PE. The incidence of DVT/PE in cirrhotics (1.8%) was lower than that in patients with other medical illnesses: 7.1% in CKD, 7.8% in CHF, and 6.1% in cancers. Conclusion Patients with cirrhosis do not have a lower risk of DVT/PE than non-cirrhotic controls without other significant co-morbidities, such as CHF, CKD, and solid organ cancers. Partial thromboplastin time and serum albumin were found to be independently predictive of DVT/PE in cirrhotic patients. [ABSTRACT FROM AUTHOR]

Renal artery embolism was first described in 1940, but it is only recently becoming recognized as a clinically significant entity. Although relatively uncommon, it is clearly responsible for considerable morbidity in patients who experience it. The pathogenesis is typically related to cardiac thrombus formation with subsequent embolization, although other etiologies have been described. The authors present a case report followed by a review of the literature to highlight the clinical characteristics of this phenomena. Presentation, diagnostics, and treatment options will be reviewed with the aim of increasing awareness of renal artery embolism. As clinicians become more familiar with this condition, they will be more likely to consider it as a possible diagnosis in patients with a typical presentation. This will hopefully lead to improved care through prompt diagnosis and treatment, particularly as one treatment option may be time sensitive. [ABSTRACT FROM AUTHOR]

Background: Venous autografts used in cardiovascular surgery tend to deteriorate over time due to arteriosclerotic complications. Cadaveric vascular allografts represent a possible alternative for this application, but donor endothelial cells (ECs) and antigen presenting cells of the graft trigger alloresponses mediated by MHC class I (MHC I) antigen, leading to graft failure. Vascular allograft rejection might be prevented by reducing cell surface expression of MHC I and thereby lowering the immunogenicity of the grafts. Material and methods: An Intrabody approach was used to reduce MHC I expression in vascular allografts. The efficacy of an adenovirus (Ad) carrying an anti-MHC I Intrabody gene (Ad-Intrabody) was first tested in vitro using rat aortic ECs. The effect of the Ad-Intrabody was then studied in vivo by a model of rat carotid artery transplantation. Grafts were analyzed 7 and 28 days after transplantation by immunohistochemistry and real time reverse transcriptase-polymerase chain reaction. Results: Ad-Intrabody gene transfer reduced MHC I surface expression of rat ECs and inhibited in vivo alloimmune responses to carotid allografts. Decreased T cell and macrophage infiltration was observed within Ad-Intrabody transduced arterial allografts at day 28. This was associated with an inhibition of intimal thickening formation. Analysis of mRNA showed diminished levels of T cell markers and Interferon-gamma expression in the Ad-Intrabody-treated group compared with control groups. Conclusions: Ex vivo adenoviral gene transfer of an Intrabody against MHC I into rat carotid arteries prior to transplantation reduced both graft arteriosclerosis and inflammation in the absence of any systemic immunosuppression. [Copyright &y& Elsevier]

Patients with coeliac artery occlusion often remain asymptomatic due to the rich collateral blood supply (pancreaticoduodenal arcades) from the superior mesenteric artery. However, division of the gastroduodenal artery (GDA) during pancreaticoduodenectomy may result in compromised blood supply to the liver, stomach and spleen. Postoperative complications associated with this condition are rarely reported in the literature. We report two cases of coeliac artery occlusion encountered during pancreaticoduodenectomy, one of which was complicated by hepatic ischaemia and total gastric infarction postoperatively. Based on our experience and review of the literature, a management algorithm for coeliac artery stenosis encountered during pancreaticoduodenectomy is proposed [ABSTRACT FROM AUTHOR]

Objective: To compare the antihypertensive efficacy and the metabolic effects, as well as the influence on cardiac and arterial function of indapamide SR 1.5 mg with hjdrochlorothiazide 25 mg, both in combination with quinapril. Materials and methods: A minimum number of 50 hypertensive and diabetic patients will be enrolled into the study,for a period of 6 months. They will be randomized either to indapamide slow release 1.5 mg/day, or to hydrochlorothiazide 25 mg/day. Quinapril will be added from the beginning of the study,for a better control of their blood pressure. The dosage of quinapril will be titrated from 10, up to 40 mg/day, as needed for each patient. Apart from clinical and laboratory routine tests, the patients will undergo more specific examinations, such as: ambulatory blood pressure monitoring,for quantifying the antihypertensive effect of the two investigational drugs; conventional and tissue Doppler echiocardiography,for cardiac function evaluation; vascular ultrasound examination,for assessing endothelial function and arterial stiffiness. This study will provide more comparative data between indapamide and hydrochlorothiazide, in combination with quinapril, concerning not only on their antihiypertensive effect and safety, bitt also their influence on cardiac and vascular function. [ABSTRACT FROM AUTHOR]

The aim of this retrospective study was to analyse the outcomes of central venous catheter (CVC) placement carried out by an interventional radiology unit. A review of our hospital records identified 331 consecutive patients who underwent insertion of a tunnelled or non-tunnelled CVC between January 2000 and December 2004. Key outcome measures included the technical success rate of CVC insertion and the percentage of immediate (<24 h), early (24 h–30 days) and late (>30 days) complications. A total of 462 CVCs were placed under radiological guidance, with an overall success rate of 98.9%. Immediate complications included one pneumothorax, which was diagnosed 7 days after subclavian CVC insertion, and eight episodes of significant haematoma or bleeding within 24 h of CVC insertion. No cases were complicated by arterial puncture or air embolus. Catheter-related sepsis occurred in 2% of non-tunnelled CVC and 8.9% of tunnelled CVC. The overall incidence of catheter-related sepsis was 0.17 per 100 catheter days. As the demand for chemotherapy and haemodialysis grows with our ageing population, interventional radiology suites are well placed to provide a safe and reliable service for the placement of central venous access devices. [ABSTRACT FROM AUTHOR]

Abstract: We report seven cases of arterial gas embolism originating from the lung that occurred in anaesthesia and intensive care unit in the very hospital where our regional hyperbaric oxygen facility is. They complicated lung surgery or trauma and/or followed a support by positive-pressure ventilation. Diagnosis was most often delayed, because of some scepticism of the physicians confronted with a variety of clinical features. The prognosis was bad with four deaths, despite treatment with hyperbaric oxygen in three cases. [Copyright &y& Elsevier]

Decompression illness (DCI) is becoming more prevalent as more people engage in activities involving extreme pressure environments such as recreational scuba-diving. Rapid diagnosis and treatment offer these patients the best chance of survival with minimal sequelae. It is thus important that critical care physicians are able to evaluate and diagnose the signs and symptoms of DCI. The cornerstones of current treatment include the administration of hyperbaric oxygen and adjunctive therapies such as hydration and medications. However, managing patients in a hyperbaric environment does present additional challenges with respect to the particular demands of critical care medicine in an altered pressure environment. This article reviews the underlying pathophysiology, clinical presentation and therapeutic options available to treat DCI, from the intensivist's perspective. [ABSTRACT FROM AUTHOR]

Reports on case studies of patients with cerebral arterial gas embolism. Disadvantage of misdiagnosis; Consideration of sudden neurological impairment; Comparison of the outcomes.