Periorbital emphysema after dive barotrauma without radiological evidence of paranasal sinus injury.

BACKGROUND: Scuba diving has increased in popularity since its invention in 1943, with over 21 million PADI registered members worldwide. Injuries to the paranasal sinuses caused by barotrauma are the second most common after injury to the middle ear. CASE REPORT: In this paper we present a case of unilateral periorbital surgical emphysema in a 23-yr-old male commercial scuba diver with minimal symptoms following an uneventful 13-ft (4-m) dive. The only symptoms experienced were pain and pressure over the right maxillary sinus and retrorbitally. Imaging with computed tomography showed no fracture of his paranasal sinuses. DISCUSSION: The authors recommend that a high index of suspicion for paranasal sinus barotrauma should be maintained in all patients reporting minor symptoms after diving (even to shallow depths) to facilitate rapid clinical diagnosis and prompt medical management.

Chest X-ray at Emergency Admission and Potential Association with Barotrauma in Mechanically Ventilated Patients: Experience from the Italian Core of the First Pandemic Peak.

Barotrauma occurs in a significant number of patients with COVID-19 interstitial pneumonia undergoing mechanical ventilation. The aim of the current study was to investigate whether the Brixia score (BS) calculated on chest-X-rays acquired at the Emergency Room was associated with barotrauma. We retrospectively evaluated 117 SARS-CoV-2 patients presented to the Emergency Department (ED) and then admitted to the intensive care unit (ICU) for mechanical ventilation between February and April 2020. Subjects were divided into two groups according to the occurrence of barotrauma during their hospitalization. CXRs performed at ED admittance were assessed using the Brixia score. Distribution of barotrauma (pneumomediastinum, pneumothorax, subcutaneous emphysema) was identified in chest CT scans. Thirty-eight subjects (32.5%) developed barotrauma (25 pneumomediastinum, 24 pneumothorax, 24 subcutaneous emphysema). In the barotrauma group we observed higher Brixia score values compared to the non-barotrauma group (mean value 12.18 vs. 9.28), and logistic regression analysis confirmed that Brixia score is associated with the risk of barotrauma. In this work, we also evaluated the relationship between barotrauma and clinical and ventilatory parameters: SOFA score calculated at ICU admittance and number of days of non-invasive ventilation (NIV) prior to intubation emerged as other potential predictors of barotrauma.

Macklin effect on baseline chest CT scan accurately predicts barotrauma in COVID-19 patients.

PURPOSE: To validate the role of Macklin effect on chest CT imaging in predicting subsequent occurrence of pneumomediastinum/pneumothorax (PMD/PNX) in COVID-19 patients. MATERIALS AND METHODS: This is an observational, case-control study. Consecutive COVID-19 patients who underwent chest CT scan at hospital admission during the study time period (October 1st, 2020-April 31st, 2021) were identified. Macklin effect accuracy for prediction of spontaneous barotrauma was measured in terms of sensitivity, specificity, positive (PPV) and negative predictive values (NPV). RESULTS: Overall, 981 COVID-19 patients underwent chest CT scan at hospital arrival during the study time period; 698 patients had radiological signs of interstitial pneumonia and were considered for further evaluation. Among these, Macklin effect was found in 33 (4.7%), including all 32 patients who suffered from barotrauma lately during hospital stay (true positive rate: 96.9%); only 1/33 with Macklin effect did not develop barotrauma (false positive rate: 3.1%). No barotrauma event was recorded in patients without Macklin effect on baseline chest CT scan. Macklin effect yielded a sensitivity of 100% (95% CI: 89.1-100), a specificity of 99.85% (95% CI: 99.2-100), a PPV of 96.7% (95% CI: 80.8-99.5), a NPV of 100% and an accuracy of 99.8% (95% CI: 99.2-100) in predicting PMD/PNX, with a mean advance of 3.2 ± 2.5 days. Moreover, all Macklin-positive patients developed ARDS requiring ICU admission and, in 90.1% of cases, invasive mechanical ventilation. CONCLUSIONS: Macklin effect has high accuracy in predicting PMD/PNX in COVID-19 patients; it is also an excellent predictor of disease severity.

Sphenoid sinus barotrauma after free diving.

We report 2 cases of a 29- and a 37-year-old male patient both having sphenoid sinus barotrauma associated with free diving at about 12-m depth. A unilateral occupation of the sphenoid sinus was revealed in both cases by computed tomography and magnetic resonance imaging examination of the paranasal sinuses.

Barotrauma in mechanically ventilated patients with Coronavirus disease 2019: a survey of 38 hospitals in Lombardy, Italy.

BACKGROUND: The aim was to describe the incidence and risk factors of barotrauma in patients with the Coronavirus disease 2019 (COVID-19) on invasive mechanical ventilation, during the outbreak in our region (Lombardy, Italy). METHODS: The study was an electronic survey open from March 27th to May 2nd, 2020. Patients with COVID-19 who developed barotrauma while on invasive mechanical ventilation from 61 hospitals of the COVID-19 Lombardy Intensive Care Unit network were involved. RESULTS: The response rate was 38/61 (62%). The incidence of barotrauma was 145/2041 (7.1%; 95%-CI: 6.1-8.3%). Only a few cases occurred with ventilatory settings that may be considered non-protective such as a plateau airway pressure >35 cmH2O (2/113 [2%]), a driving airway pressure >15 cmH2O (30/113 [27%]), or a tidal volume >8 mL/kg of ideal body weight and a plateau airway pressure >30 cmH2O (12/134 [9%]). CONCLUSIONS: Within the limits of a survey, patients with COVID-19 might be at high risk for barotrauma during invasive (and allegedly lung-protective) mechanical ventilation.

Role of routine chest radiography after percutaneous dilatational tracheostomy.

BACKGROUND: The role of routine chest radiography (CXR) after percutaneous dilatational tracheostomy (PDT) has been questioned. METHODS: We performed a prospective observational study, on a mixed medical/surgical critical care unit in a university teaching hospital. We studied all patients undergoing PDT as part of their critical care management from November 1, 2003 until July 31, 2007. All PDTs were performed under bronchoscopic guidance. After PDT, we reviewed the immediate post-procedural films to assess the utility of routine postoperative CXR. For the purposes of CXR review, we considered a procedure to be either uncomplicated or technically difficult. Clinically relevant CXR findings were new barotrauma (pneumothorax, pneumomediastinum) or a significant change in consolidation from the pre-procedure film. RESULTS: A total of 384 patients underwent PDT during the study period. Of these, 345 had immediate post-procedural CXRs available for review. There were 252 PDTs (73%) documented as uncomplicated. There were 93 (27%) technically difficult procedures, with 107 adverse events recorded. In 82 (24%) procedures, these difficulties were described as minor procedural complications [multiple attempts at needle insertion (> or = 3), minor bleeding or tracheal ring fracture]. Significant complications (mal-placement in the anterior mediastinum and major bleeding) were documented in 12 (3.5%) patients. New abnormalities were noted on 8 (2.3%) immediate post-procedural CXRs. In only one patient was there a new CXR change in an uncomplicated PDT. CONCLUSIONS: Immediate CXR after uncomplicated PDT performed under bronchoscopic guidance rarely reveals unexpected radiological abnormalities. The role of CXR after PDT appears to be restricted to those patients undergoing technically difficult and complicated procedures. A change in practice to this effect will lead to reductions in both medical costs and exposure of staff and patients to ionizing radiation.

Barotrauma and decompression illness of the inner ear: 46 cases during treatment and follow-up.

INTRODUCTION: Diving accidents affecting the inner ear are much more common than was once thought. Among the 319 patients treated in our clinic between January 2002 and November 2005, 46 cases involved 44 divers with symptoms of acute inner ear disorders. The objective of the present article is to investigate the symptoms of the acute disorders and assess any residual damage. STUDY DESIGN: Retrospective case analysis. MATERIALS AND METHODS: The medical records were used to study the cases of 18 divers treated for inner ear decompression illness on 20 occasions and 26 divers who had inner ear barotrauma. The symptoms of the disorder at the beginning of treatment, latency period before the first therapeutic measures, kind of initial therapy, symptoms after the accident, and hearing and balance functions at the last examination in our clinic were assessed. Divers with inner ear decompression illness were examined via means of transcranial or carotid Doppler ultrasonography for the presence of a vascular right-to-left (R/L) shunt. RESULTS: Of 18 divers with inner ear decompression illness, 17 reported vertigo as the main symptom. In one diver, the inner ear decompression illness was manifested bilaterally. The divers with inner ear decompression illness had been treated with hyperbaric oxygen therapy in 14 of 20 cases; the average latency period before the start of therapy was 40 hours (median, 10 h). In 15 (83%) of 18 patients, a large R/L shunt was detected, and in 14 (78%) of 18 patients, residual cochleovestibular damage was detected. Only 9 of 26 patients with inner ear barotrauma mentioned feeling dizzy, and in no patient was vertigo the main symptom. Twenty-one patients complained of tinnitus, whereas 20 complained of hearing loss. The hearing loss ranged from an unobtrusive difference of 10 dB between the ears up to complete deafness. Three patients were subjected to tympanoscopy because of suspected rupture of the round window membrane. Of patients with inner ear barotrauma, 78% had residual cochleovestibular damage. CONCLUSION: We describe for the first time a patient with bilateral manifestation of inner ear decompression illness. Inner ear decompression illness is frequently associated with a R/L shunt; therefore, after a diving accident, the patient's fitness to dive should be assessed via a specialist in diving medicine. Both decompression illness and barotrauma of the inner ear result in residual cochleovestibular damage in more than three of four patients.

Periorbital emphysema after a wet chamber dive.

Although periorbital emphysema (PE) is commonly associated with orbital fractures, it may develop without any fracture or significant trauma in circumstances such as post-surgery, infection, forceful nose blowing, sneezing, and weight lifting. We report on a healthy military diver who developed PE following a wet chamber dive. A diagnosis of PE secondary to sinus barotrauma was reached. He was treated conservatively without medication and his symptoms recovered completely within 10 days. To the best of our knowledge, only five cases of diving-related PE have been reported in the literature. Analysis of these cases and ours revealed that facial trauma, repeated forceful Valsalva manoeuvres and recent upper respiratory tract infection are probable risk factors for diving-related PE.

Point-of-Care Ultrasound Utility and Potential for High Altitude Crew Recovery Missions.

INTRODUCTION: Flights to high altitude can lead to exposure and unique pathology not seen in normal commercial aviation. METHODS: This paper assesses the potential for point-of-care ultrasound to aid in management and disposition of injured crewmembers from a high altitude incident. This was accomplished through a systematic literature review regarding current diagnostic and therapeutic uses of ultrasound for injuries expected in high altitude free fall and parachuting. RESULTS: While current research supports its utility in diagnostics, therapeutic procedures, and triage decisions, little research has been done regarding its utility in high altitude specific pathology, but its potential has been demonstrated. DISCUSSION: An algorithm was created for use in high altitude missions, in the event of an emergency descent and traumatic landing for an unconscious and hypotensive pilot, to rule out most life threatening causes. Each endpoint includes disposition, allowing concise decision-making.Galdamez LA, Clark JB, Antonsen EL. Point-of-care ultrasound utility and potential for high altitude crew recovery missions. Aerosp Med Hum Perform. 2017; 88(2):128-136.

Intrapulmonary bronchogenic cyst and cerebral gas embolism in an aircraft flight passenger.

Although it is estimated that > 1 billion passengers travel by air worldwide each year, the incidence of in-flight emergencies is low. However, due to nonstandardized reporting requirements for in-flight medical emergencies, the true incidence of pulmonary barotrauma in airplane passengers is unknown. We describe the case of a passenger with an asymptomatic intrapulmonary cyst in whom a severe case of cerebral gas embolism developed during an aircraft flight. The decrease in ambient pressure during the aircraft climb resulted in expansion of the cyst volume based on Boyle's law (pressure x volume = constant). Due to the cyst expansion, we believe tears in the wall led to the leakage of air into the surrounding vessels followed by brain gas emboli. Adult patients with intrapulmonary cysts should be strongly considered for cyst resection or should at least be advised to abstain from activities leading to considerable changes in ambient pressure.

Magnetic resonance imaging in a guinea pig model of inner ear decompression sickness and barotrauma.

OBJECTIVES/HYPOTHESIS: Scuba diving may cause severe hearing loss and vertigo due to inner ear barotrauma and decompression sickness. These may be difficult to differentiate clinically. Decompression sickness requires costly and potentially dangerous hyperbaric therapy, whereas such treatment may worsen barotrauma. The objective of this study was to assess the potential utility of magnetic resonance imaging to identify and distinguish blood from air in the inner ear, manifestations of barotrauma and decompression sickness, using a guinea pig model. STUDY DESIGN: Prospective animal trial. METHODS: Magnetic resonance of the head was performed at 3 Tesla, pre- and postinjection of 2, 4, or 10 µL of air or blood through the round window into the perilymph. With this model, 2 µL has been shown to cause hearing loss. Images were reviewed by a neuroradiologist blinded to the treatment. RESULTS: All 14 normal ears, five of seven blood- and five of seven air-injected ears, were correctly interpreted. Two blood- and one air-injected ear were interpreted as indeterminate. One air-injected ear was incorrectly interpreted as blood. CONCLUSIONS: Magnetic resonance reliably distinguishes small volumes of air and blood in the guinea pig inner ear. Magnetic resonance should be evaluated for its utility in the diagnosis of inner ear barotrauma and decompression sickness in scuba divers. LEVEL OF EVIDENCE: NA Laryngoscope, 126:2106-2109, 2016.

Middle ear barotrauma causing transient facial nerve paralysis after scuba diving.

Middle ear barotrauma is a well known entity with typical injury occurring when diving or ascending in a commercial jetliner. Patients often present with symptoms of acute onset otalgia, hearing loss and sometimes haemotympanum (with or without tympanic membrane perforation). On rare occasions, facial nerve paralysis can occur when the tympanic segment of the facial nerve is dehiscent within the middle ear. We present a case of spontaneously resolving facial nerve palsy associated with middle ear barotrauma following a brief, shallow dive. Prompt and astute diagnosis leads to proper management with simple myringotomy and can prevent unnecessary testing and other misguided treatments.

[Frontal sinus barotrauma: about a case and review of the literature]. / Barotraumatisme du sinus frontal à propos d'un cas et revue de la littérature.

Sinus barotrauma is the second most frequently reported injury after middle ear barotrauma. The front sinus is the most common site affected. This is a rare and specific pathology. We here report the case of a 26-year-old patient having severe left frontal pain with ipsilateral epistaxis after a dive. CT scan showed left frontal hemosinus. Patient evolution was good after therapy. Frontal sinus barotraumas are accidents related to the variations in environmental pressure. Epistaxis is a sign of serious health condition, CT scanner plays a role in evaluating potential predisposing factors and establishing monitoring procedures. Patient treatment aims to relieve symptoms and to remove predisposing factors. Frontal sinus barotraumas are a rare injury ; orbital and encephalic complications are exceptional. Their treatment coincides with that of their causal pathology.

The role of radiology in dive-related disorders.

Recreational scuba diving has continued to grow in popularity in the past several decades, and military diving remains an integral part of ship husbandry, explosives and ordinance disposal, and special warfare. Although relatively uncommon, disorders such as decompression sickness and arterial gas embolism can be fatal, whereas disorders such as ear baro-trauma and dysbaric osteonecrosis are not fatal but can cause significant morbidity. An extensive literature search was performed to comprehensively examine the current role of diagnostic radiology with respect to diving medicine. In selected cases, diagnostic imaging can be of potential benefit for evaluation. Diagnostic imaging plays a useful role in the screening of certain individuals for future fitness to dive. Radiological imaging has also been of paramount importance in postmortem evaluation of dive casualties.

[The predictive value of assessing mastoid pneumatization in pre-dive examinations]. / Dalici muayenesinde mastoid pnömatizasyon derecesinin barotravmayi öngörmedeki degeri.

OBJECTIVES: We investigated the value of assessing the degree of mastoid pneumatization in predicting middle ear barotrauma -the most common problem in sport SCUBA divers- in comparison with that of the conventional pre-dive examination method, the Valsalva maneuver. MATERIALS AND METHODS: Thirty-four volunteer sport SCUBA divers having normal pre-dive examination findings were included. The Valsalva test was performed in all the divers. Mastoid pneumatization for each ear was calculated on a Schuller's view radiography. Pneumatization of = or <30 cm2 was accepted as poor (prone to barotrauma) and >30 cm2 was accepted as good (not prone to barotrauma). During the observation period, the divers were monitored with regard to barotrauma symptoms and signs. RESULTS: The degree of mastoid pneumatization was = or <30 cm2 in 26 ears (38%) of 16 divers (47%). The Valsalva test was negative in eight ears (12%) of six divers (18%). During a total of 1001 dives, symptomatic middle ear barotrauma occurred in 28 dives (2.8%), i.e. in 21 ears (31%) of 16 divers (47%). Of these, the degree of mastoid pneumatization predicted barotrauma in 11 (69%) divers, whereas the Valsalva test was negative in only three (19%) (p<0.05), with sensitivity, specificity, positive and negative predictive values, and efficiency being 69% and 19%, 72% and 83%, 69% and 50%, 72% and 54%, and 71% and 53%, respectively. CONCLUSION: The value of assessing mastoid pneumatization in predicting middle ear barotrauma in sport SCUBA divers is higher than that of the Valsalva test.

Radiographic assessment of hyperinflation: correlation with objective chest radiographic measurements and mechanical ventilator parameters.

BACKGROUND: Pulmonary barotrauma is a potentially fatal complication of positive pressure ventilation. We previously found that barotrauma occurred in patients with radiographic hyperinflation, but few objective data define the relationships among hyperinflation, objective chest radiograph (CXR) measurements, ventilator parameters, and development of barotrauma. OBJECTIVES: We sought (1) to assess the relationships among hyperinflation, objective CXR findings, mechanical ventilator parameters, and development of barotrauma. (2) To compare radiographic hyperinflation, ventilator parameters, and incidence of barotrauma in a current group of ICU patients with historical control subjects. SETTING: Medical and surgical ICU patients in a university hospital. DESIGN: Prospective blinded observational study; comparison of current series with historical control subjects. METHODS: One hundred two prospectively enrolled mechanically ventilated medical and surgical ICU patients each received portable supine CXRs that were reviewed independently by three radiologists who made objective measurements and subjectively determined the likelihood of hyperinflation. Ventilator parameters were recorded at the bedside at the time each CXR was obtained. CXR measurements and ventilator parameters were then related to the development of barotrauma during the course of ventilation and compared with findings of a prospective study at our institution 1 year earlier. RESULTS: Radiographically recognizable hyperinflation occurred in 18 of 102 mechanically ventilated ICU patients (18%) and correlated with lung length (24.7 vs 19.8 cm; p<0.05) and the anterior rib number that intersects the hemidiaphragm (5.4 vs 4.7; p<0.05). Patients with hyperinflation were ventilated at higher tidal volume per kilogram (VT/kg) (11.0 vs 9.4; p=0.0081), but peak airway pressure, plateau pressure, and positive end-expiratory pressure were similar. There were significant decreases in VT (810 vs 739 mL; p=0.015) and VT/kg (11.0 vs 10.1 mL/kg; p<0.001) in these mechanically ventilated ICU patients in comparison to hospital control subjects evaluated during the previous year. Paralleling these changes was a decrease in the frequency of CXR hyperinflation (p=0.003) and the incidence of ventilator-associated barotrauma (6.5% vs 0.98%; p=0.048). CONCLUSIONS: Ventilation at higher VT/kg is associated with a higher incidence of CXR hyperinflation. Radiographic hyperinflation is associated with lung length > or =24.7 cm and visualization of the sixth anterior rib. Patients with hyperinflation may be at greater risk for developing barotrauma or volutrauma. Ventilatory strategies utilizing lower volumes are associated with a lower incidence of such trauma in the current sample as compared with historical control subjects.

Portable chest radiographs identify mechanical ventilator-associated hyperinflation.

OBJECTIVE: Portable chest radiographs (CRs) are obtained routinely in mechanically ventilated patients, but little is known about relationships between CR findings and ventilator parameters. It is unclear whether radiographically apparent hyperinflation correlates with tidal volume (VT), body weight (BW), VT/kg, or levels of peak airway pressure (PAP), positive end-expiratory pressure (PEEP), or pressure support (PS). DESIGN: Prospective comparison of CR and ventilator parameters in 62 mechanically ventilated patients in surgical and medical intensive care units of a university hospital. PATIENT SELECTION: All mechanically ventilated adults with portable CR on four separate dates. METHODS: Chest radiographs were classified by subjective assessments as hyperinflated (H+) or nonhyperinflated (H-), independent of knowledge of patients or their mechanical ventilation. Chest radiographs were reclassified independently as H+, H-, or indeterminate by a radiologist using objective criteria. Ventilator parameters recorded at the time of the CR were obtained and compared. RESULTS: Patients with CRs classified subjectively as H+ compared with patients with CRs classified as H- had a larger VT/kg (12.0 +/- 0.4 ml/kg [mean +/- SEM] vs 10.2 +/- 0.4; p = 0.004), lower BW (70.8 +/- 2.9 kg vs 81.5 +/- 3.8; p = 0.03), higher PEEP (6.5 +/- 0.5 cm H2O vs 5.0 +/- 0.4; p = 0.01), and higher PAP (38.2 +/- 2.1 cm H2O vs. 33.4 +/- 1.8; p = 0.06). Using objective CR classifications, patients with H+ CRs had a VT/kg of 12.6 +/- 0.4, larger than in the indeterminate (11.1 +/- 0.8) and H- (9.9 +/- 0.3) groups (p < 0.001). The BW differed among objectively classified groups (66.5 +/- 2.7 H+, 68.9 +/- 5.1 indeterminate, and 85.2 +/- 3.7 H-; p < 0.001), but other ventilator parameters did not correlate univariately with the degree of inflation on CR. Multivariate analysis showed that higher VT was predictive of H+ after adjusting for BW in subjective (p = 0.076) and objective (p = 0.017) classifications. PEEP (p = 0.004) and older age (p = 0.021) were also associated with H+ in multivariate analysis. Four of 25 (16 percent) patients with objectively H+ CRs developed barotrauma, while no patient with H- CR had this complication (p = 0.037). CONCLUSIONS: In mechanically ventilated patients, hyperinflation seen on portable CR is associated with higher VT, VT/kg, and lower BW, and may help predict subsequent barotrauma.

Risk factors for pulmonary barotrauma in divers.

STUDY OBJECTIVES: Pulmonary barotrauma (PBT) of ascent is a feared complication in compressed air diving. Although certain respiratory conditions are thought to increase the risk of suffering PBT and thus should preclude diving, in most cases of PBT, risk factors are described as not being present. The purpose of our study was to evaluate factors that possibly cause PBT. DESIGN: We analyzed 15 consecutive cases of PBT with respect to dive factors, clinical and radiologic features, and lung function. They were compared with 15 cases of decompression sickness without PBT, which appeared in the same period. RESULTS: Clinical features of PBT were arterial gas embolism (n=13), mediastinal emphysema (n=1), and pneumothorax (n=1). CT of the chest (performed in 12 cases) revealed subpleural emphysematous blebs in 5 cases that were not detected in preinjury and postinjury chest radiographs. A comparison of predive lung function between groups showed significantly lower midexpiratory flow rates at 50% and 25% of vital capacity in PBT patients (p<0.05 and p<0.02, respectively). CONCLUSIONS: These results indicate that divers with preexisting small lung cysts and/or end-expiratory flow limitation may be at risk of PBT.

Barotrauma as a possible cause of aneurysmal subarachnoid hemorrhage. Case report.

The authors report the case of a 47-year-old man who suffered a diving accident. After regaining consciousness he experienced severe headache. He was initially treated for barotrauma, but the persistent headache led to diagnostic imaging that revealed an aneurysmal subarachnoid hemorrhage. To the authors' knowledge, this is the first report of a ruptured brain aneurysm associated with barotrauma.