Prediction for the prognosis of diffuse axonal injury using automated pupillometry.

OBJECTIVE: Previous studies have reported various predictive indicators of diffuse axonal injury (DAI), but no consensus has not been reached. Although the efficiency of automated pupillometry in patients with consciousness disorder has been widely reported, there are few reports of its use in patients with DAI. This study aimed to investigate the significance of pupillary findings in predicting the prognosis of DAI. PATIENTS AND METHODS: We included patients admitted to our center with a diagnosis of DAI from June 1, 2021 to June 30, 2022. Pupillary findings in both eyes were quantitatively measured by automated pupillometry every 2 hours after admission. We statistically examined the correlations between automated pupillometry parameters, the patients' characteristics, and outcomes such as the Glasgow Outcome Scale Extended (GOSE) after 6 months from injury, the time to follow command, and so on. RESULTS: Among 22 patients included in this study, five had oculomotor nerve palsy. Oculomotor nerve palsy was correlated with all outcomes, whereas Marshall computed tomography (CT) classification, Injury severity score (ISS) and DAI grade were correlated with few outcomes. Some of the automated pupillometry parameters were significantly correlated with GOSE at 6 months after injury, and many during the first 24 hours of measurement were correlated with the time to follow command. Most of these results were not affected by adjustment using sedation period, ISS or Marshall CT classification. A subgroup analysis of patients without oculomotor nerve palsy revealed that many of the automated pupillometry parameters during the first 24 hours of measurement were significantly correlated with most of the outcomes. The cutoff values that differentiated a good prognosis (GOSE 5-8) from a poor prognosis (GOSE 1-4) were constriction velocity (CV) 1.43 (AUC = 0.81(0.62-1), p = 0.037) and maximum constriction velocity (MCV) 2.345 (AUC = 0.78 (0.58-0.98), p = 0.04). The cutoff values that differentiated the time to follow command into within 7 days and over 8 days were percentage of constriction 8 (AUC = 0.89 (0.68-1), p = 0.011), CV 0.63 (AUC = 0.92 (0.78-1), p = 0.013), MCV 0.855 (AUC = 0.9 (0.74-1), p = 0.017) and average dilation velocity 0.175 (AUC = 0.95 (0.86-1), p = 0.018). CONCLUSIONS: The present results indicate that pupillary findings in DAI are a strong predictive indicator of the prognosis, and that quantitative measurement of them using automated pupillometry could facilitate enhanced prediction for the prognosis of DAI.

Massive Hemorrhage Associated With Upper Cervical Vertebral Fracture Treated Successfully With Transcatheter Arterial Embolization: A Case Report.

Blunt vertebral artery injuries (BVAI) associated with cervical spine fractures are often problematic due to symptoms of occlusion. Denver grade V cases, in which the vertebral artery is transected, are rare but often fatal, and treatment has rarely been reported. We encountered a case of hemorrhagic shock due to an injury to a branch of the vertebral artery associated with an upper cervical spine fracture. Transcatheter arterial embolization was performed successfully to achieve hemostasis, requiring superselective arterial embolization to preserve the main trunk of the vertebral artery. It is important to be aware that vascular injuries to the branch vessels as well as the main trunk can cause complications.

Effect of ionized calcium level on short-term prognosis in severe multiple trauma patients: a clinical study.

Background: Hypocalcemia has been reported as an independent predictor of trauma mortality. We investigated the relationship between temporal variations in blood ionized calcium concentration (iCa) and prognosis in severe trauma patients who underwent massive transfusion protocol (MTP). Methods: This single-center, retrospective, observational study investigated 117 severe trauma patients treated with MTP in the Department of Emergency Medicine and Critical Care, Saitama Medical Center, Saitama Medical University, between March 2013 and March 2019. Multivariate logistic regression analysis was performed, assigning pH-corrected initial and minimum blood ionized calcium concentration within 24 hours of admission (iCa_min), age, initial systolic blood pressure and Glasgow Coma Scale (GCS) score, and incidence of Ca supplementation as independent variables and 28-day mortality as dependent variable. Results: The logistic regression analysis identified iCa_min (adjusted OR 0.03, 95% CI 0.002 to 0.4), age (adjusted OR 1.05, 95% CI 1.02 to 1.09), and GCS score (adjusted OR 0.84, 95% CI 0.74 to 0.94) as significant independent predictors of 28-day mortality. The receiver operating characteristic analysis identified optimal cut-off value of iCa_min for predicting 28-day mortality as 0.95 mmoL/L (area under the curve 0.74). Conclusion: In the management of patients with traumatic hemorrhagic shock, aggressive correction of the iCa to maintain 0.95 mmol/L or higher within 24 hours of admission may improve short-term outcomes. Level of evidence: Therapeutic/care management, level III.

Hemorrhagic Shock Due to Traumatic Anterior Cerebral Artery Aneurysm: A Case Report.

Massive subdural hematomas are known to cause hemorrhagic shock in infants and young children. Traumatic cerebral aneurysms are rare and are often noticed in the subacute phase with disorientation due to the rupture of a pseudoaneurysm. No previous studies appear to have clarified the diagnosis of and therapeutic interventions for traumatic cerebral aneurysms identified from computed tomography (CT) on admission. The present case involved an open skull fracture resulting in hemorrhagic shock due to subcutaneous extravasation from an anterior cerebral artery (ACA) pseudoaneurysm. A seven-year-old boy was accidentally struck by a car after running out into a road. He had an open fracture of the skull and contrast-enhanced CT of the head showed subcutaneous extravasation from the ACA. The patient developed hemorrhagic shock that resolved following the embolization of the ACA with n-butyl-2-cyanoacrylate. Head trauma can cause hemorrhagic shock in the presence of an open wound due to a skull fracture. Contrast-enhanced CT of the head on admission is useful for diagnosis.

Immediate Closed Reduction Technique for Cervical Spine Dislocations.

STUDY DESIGN: Retrospective study. PURPOSE: This research aimed to assess the clinical outcomes of patients with traumatic cervical spine dislocation who underwent closed reduction employing our approach. OVERVIEW OF LITERATURE: Bedside closed reduction is the quickest procedure for repairing traumatic cervical spine dislocations; nevertheless, it also possesses the risk of neurological deterioration. METHODS: For closed reduction, the patient's head was elevated on a motorized bed, the cervical spine was placed at the midline, traction of 10 kg was applied, the motorized bed was gradually returned to a flat position, the head was lifted off the bed, and the cervical spine was slowly adjusted to a flexed position. The weight of traction was elevated by 5-kg increments until the positional shift was attained. Subsequently, the bed was gradually tilted while traction was applied again to return the cervical spine to the midline position. RESULTS: Of the 43 cases of cervical spine dislocation, closed reduction was carried out in 40 cases, of which 36 were successful. During repositioning, three patients experienced a temporary worsening of their neck pain and neurological symptoms that enhanced when the cervical spine was flexed. Closed reduction was conducted while the patient was awake; nevertheless, sedation was needed in three cases. Among the 24 patients whose pretreatment paralysis had been characterized by American Spinal Injury Association Impairment Scale (AIS) grades A-C, seven patients (29.2%) demonstrated an enhancement of two or more AIS grades at the last observation. CONCLUSIONS: Our closed reduction approach safely repaired traumatic cervical spine dislocations.

Arterialization of plantar venous system via vein graft: A novel technique for reconstruction of heel pad degloving injuries.

BACKGROUND: Patients with heel pad degloving injury frequently develop ischemic necrosis of the area, necessitating soft-tissue reconstruction surgery. We have developed a technique for arterialization of the plantar venous system via vein graft (APV) as the primary revascularization treatment. The objective of this study was to clarify both the utility of APV for the preservation of degloved heel pads and the impact of this preservation on clinical outcomes. METHODS: Ten consecutive cases of degloving injury with devascularized heel pad were treated at a single trauma center from 2008 to 2018. Five cases underwent APV and five underwent conventional primary suture (PS) as the initial treatment. We evaluated the course according to the frequency of heel pad preservation, additional intervention after heel pad necrosis, post-operative complications, and outcomes using the Foot and Ankle Disability Index score (FADI) at the time of last follow-up. RESULTS: Among the five cases that underwent APV, the heel pad was preserved in three cases and flap surgery was required in two cases. All cases that underwent PS developed necrosis of the heel pad, requiring skin graft in one case and flap surgery in four. One skin graft case and one free flap case after PS developed plantar ulcers. The three cases with preserved heel pads exhibited higher FADI than the seven cases that developed necrosis. CONCLUSION: APV showed a relatively high frequency of heel pad preservation, which otherwise was uniformly lacking. Functional outcomes were improved in cases with preserved heel pad compared to those that developed necrosis and underwent additional tissue reconstruction.

Successful artificial pneumothorax thoracoscopic repair of a right-sided diaphragmatic injury with hemothorax. A case report.

INTRODUCTION AND IMPORTANCE: Right-sided blunt diaphragmatic injury (BDI) is rare and often missed initially. Recently, some studies reported increased use of minimally invasive repair. A case of unexplained hemothorax that led to early suspicion of right-sided BDI, which was confirmed by exploratory thoracoscopy with an artificial pneumothorax, and primary repair was completed, is presented. CASE PRESENTATION: A 47-year-old woman had a moderate right hemothorax without rib fracture, vertebral fracture, or lung injury. A chest tube was inserted for the hemothorax, and approximately 470 mL of blood were evacuated initially. The right-sided BDI was not initially identified. Diagnostic thoracoscopy with an artificial pneumothorax confirmed diaphragmatic laceration. The liver was pushed back into the abdominal cavity with the use of the artificial pneumothorax. Primary closure of the diaphragmatic laceration was performed. CLINICAL DISCUSSION: We must consider that a hemothorax without a lung injury or a chest wall injury may be a BDI. Thoracoscopy contributes to identifying and repairing a diaphragmatic injury. Additionally, an artificial pneumothorax provided a good operative field and spontaneously reduced the liver into the abdominal cavity, which facilitates the thoracoscopic repair of BDI. CONCLUSION: Unexplained hemothorax may be due to diaphragmatic injury, and exploratory thoracoscopy with an artificial pneumothorax may contribute to identifying and repairing a diaphragmatic injury.

Infant Caudate Lobe Injury With Retroperitoneal Hematoma: A Case Report.

Liver injury, especially caudate lobe injury, is an extremely rare form of injury in infants. In most cases, liver injury results in intraperitoneal hemorrhage when the capsule is ruptured, and circulatory dynamics deteriorate early. Caudate lobe injuries, however, often present with a high retroperitoneal hematoma. The diagnosis is difficult to identify with a focused assessment with sonography for trauma (FAST) in the initial treatment of trauma and may even be delayed without contrast-enhanced CT imaging. A one-month-old postoperative boy with congenital heart disease was involved in a motor vehicle accident and presented with a single caudate lobe injury. He was not wearing a seatbelt, and it was thought that the caudate lobe was injured due to shearing forces in the cephalocaudal direction at the time of the accident. The patient did not go into shock when he first came to our hospital, but a few hours after admission, he went into shock and required surgical hemostasis. The postoperative course was good, and the patient was discharged alive one month later. The lesson to be learned from this case is that caudate lobe injuries are often associated with retroperitoneal hematoma and slow deterioration of hemodynamics, so it is important not to miss small changes in the child's vitals and to be willing to perform contrast-enhanced CT imaging depending on the type of injury.

Single-staged laparotomy versus multiple-staged laparotomy for traumatic massive hemoperitoneum with hemodynamic instability: a single-center, propensity score-matched analysis.

BACKGROUND: Currently, damage control surgery (DCS) employing multiple-staged laparotomy (MSL) is a standard hemostatic approach for treating trauma patients with unstable hemodynamics attributable to massive hemoperitoneum. Based on these findings, we had frequently employed MSL as a part of our hemostatic strategy for the patients, but with unsatisfactory outcomes. On the other hand, with the establishment of damage control resuscitation (DCR), it has become possible to avoid trauma-induced coagulopathy and to achieve adequate hemostasis with single-staged laparotomy (SSL). Consequently, our institutional strategy for surgical hemostasis of the patients has gradually shifted from MSL to SSL with implementation of DCR. The purpose of the study is to evaluate the impact of this shift in the strategy by comparing outcomes of the patients between those underwent MSL and those underwent SSL employing propensity score matching. METHODS: This retrospective, single-center, observational study evaluated outcomes of hemodynamically unstable patients with traumatic massive hemoperitoneum requiring surgical intervention between 2005 and 2020. The patient population was divided into two groups: a SSL group and a MSL group. Propensity score matching was used to adjust for differences in baseline characteristics in the two groups, a one-to-one matched analysis using nearest-neighbor matching was performed based on the estimated propensity score of each group. The primary outcome was in-hospital mortality, and secondary outcomes were 48-h mortality and 28-day mortality. RESULTS: A total of 170 patients met the inclusion criteria; 141 patients underwent SSL, and 29 underwent MSL. In the propensity-matched analysis with 27 pairs, the SSL group had significantly lower in-hospital mortality (odds ratio [OR] 0.154; 95% confidence interval (CI) 0.035 to 0.682) and 28-day mortality (OR 0.200; 95% CI 0.044 to 0.913) than the MSL group, but the 48-h mortality did not differ significantly between the two groups (25.9% vs. 44.4%; OR 0.375; 95% CI 0.099-1.414). CONCLUSIONS: Single-staged laparotomy may be an effective surgical treatment for the traumatic massive hemoperitoneum cases with hemodynamic instability, if conducted following sufficient damage control resuscitation and performed by an experienced surgeon.

SARS-CoV-2 RNA load and detection rate in exhaled breath condensate collected from COVID-19 patients infected with Delta variant.

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) Delta variant is considered responsible for worldwide surges in coronavirus disease 2019 (COVID-19) cases in 2021, with increased infectivity compared to the wild type (Wuhan-1). In a previous study, we identified temporal changes in wild-type SARS-CoV-2 RNA load and detection rate in EBC collected from COVID-19 patients. The primary objective of this study was to clarify temporal changes in Delta-variant SARS-CoV-2 RNA load and detection rates in EBC collected from patients, and to validate the feasibility of Delta-variant SARS-CoV-2 RNA detection from EBC for diagnosing COVID-19. The secondary objective was to compare SARS-CoV-2 RNA loads in EBC between Delta-variant and wild-type. Subjects were 41 COVID-19 patients infected with the Delta-variant. EBC samples were collected from subjects on the day of or the day after admission using R-tube® (Respiratory Research, Austin, Texas, USA), as in our previous study. SARS-CoV-2 RNA in EBC samples was detected and quantified by RT-PCR assay targeting the E gene, using the same settings and reagents as in the previous study. The results indicated that SARS-CoV-2 RNA load in EBC collected from subjects infected with Delta-variant decreased exponentially with the passage of days from symptom onset. Sustained high detection rates support the feasibility of Delta-variant SARS-CoV-2 RNA detection from EBC by RT-PCR assay as a diagnostic test for COVID-19 within 8 d of onset. SARS-CoV-2 RNA load in EBC collected 2-8 d from onset was significantly higher in Delta-variant-infected subjects than in wild-type-infected subjects on a day-to-day basis (p= 0.005-0.029). However, because of the heterogeneity of the study cohort, conclusions cannot be reached regarding differences in viral RNA load between strains, regardless of the timing of EBC collection.

A perspective on hospital-acquired (nosocomial) infection control of COVID-19: usefulness of spatial separation between wards and airborne isolation unit.

The coronavirus disease 2019 (COVID-19) pandemic has imposed a considerable burden on hospitals and healthcare workers (HCWs) worldwide, increasing the risk of outbreaks and nosocomial transmission to 'non-COVID-19' patients, who represent the highest-risk population in terms of mortality, and HCWs. Since HCWs are at the interface between hospitals on the one hand and the community on the other, they are potential reservoirs, carriers, or victims of severe acute respiratory syndrome coronavirus 2 cross-transmission. In addition, there has been a paradigm shift in the management of viral respiratory outbreaks, such as the widespread testing of patients and HCWs, including asymptomatic individuals. In hospitals, there is a risk of aerosol transmission in poorly ventilated spaces, and when performing aerosol-producing procedures, it is imperative to take measures against aerosol transmission. In particular, spatial separation of the inpatient ward for non-COVID-19 patients from that designated for patients with suspected or confirmed COVID-19 as well as negative-pressure isolation on the floor of the ward, using an airborne infection isolation device could help prevent nosocomial infection.

RT-PCR diagnosis of COVID-19 from exhaled breath condensate: a clinical study.

Current diagnostic testing for coronavirus disease 2019 (COVID-19) is based on detection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in nasopharyngeal swab samples by reverse transcription polymerase chain reaction (RT-PCR). However, this test is associated with increased risks of viral dissemination and environmental contamination and shows relatively low sensitivity, attributable to technical deficiencies in the sampling method. Given that COVID-19 is transmitted via exhaled aerosols and droplets, and that exhaled breath condensate (EBC) is an established modality for sampling exhaled aerosols, detection of SARS-CoV-2 in EBC offers a promising diagnostic approach. However, current knowledge on the detection and load of the virus in EBC collected from COVID-19 patients remains limited and inconsistent. The objective of the study was to quantify the viral load in EBC collected from COVID-19 patients and to validate the feasibility of SARS-CoV-2 detection from EBC as a diagnostic test for the infection. EBC samples were collected from 48 COVID-19 patients using a collection device, and viral loads were quantified by RT-PCR targeting the E gene. Changes in detection rates and viral loads relative to patient characteristics and days since disease onset were statistically evaluated. Need for mechanical ventilation was significantly associated with higher viral load (p< 0.05). Need for oxygen administration or mechanical ventilation, less than 3 d since onset, and presence of cough or fever were significantly associated with higher detection rates (p< 0.05). Among spontaneously breathing patients, viral load in EBC attenuated exponentially over time. The detection rate was 86% at 2 d since onset and deteriorated thereafter. In mechanically ventilated patients, detection rate and viral load were high regardless of days since onset. These results support the feasibility of using RT-PCR to detect SARS-CoV-2 from EBC for COVID-19 patients within 2 d of symptom onset.

A short perspective on a COVID-19 clinical study: 'diagnosis of COVID-19 by RT-PCR using exhale breath condensate samples'.

Diagnosis of SARS-COV-2 infection (COVID-19) is currently based on detection of the viral RNA in nasopharyngeal swab samples by reverse transcription polymerase chain reaction (RT-PCR). However, sampling via nasopharyngeal swabs frequently provokes sneezing or coughing, which results in increased risk of the viral dissemination and environmental contamination. Furthermore, the sensitivity associated with the PCR tests s limited to 60%-70%, which is mainly attributable to technical deficiency in sampling. Given that the disease is transmitted via exhaled aerosol and droplets, and that the exhaled breath condensate (EBC) is the established modality for sampling exhaled aerosol, detection of the viral RNA in EBC is a promising approach for safe and efficient diagnosis of the disease. Subjects are those patients who are diagnosed with COVID-19 by positive nasopharyngeal swab PCR test and admitted to Saitama Medical Center, Japan. EBC samples will be collected using an R-tube® or R-tubeVent® device. Collected EBC samples will be introduced into a nucleic acid purifier. The purified nucleic acids will undergo amplification through RT-PCR for detection and quantification of SARS-COV-2 RNA. To date we have collected eight samples from seven subjects. Among them, two samples from two subjects tested positive for SARS-COV-2 RNA by the RT-PCR. Reflecting the second wave of COVID-19 prevalence in Japan, new admissions of COVID-19 patients to the Saitama Medical Center are increasing, and we are expecting to collect at least 50 EBC samples from 25 patients before the end of this year.

Two-Staged Circumferential Decompression and Fusion Surgery for Upper Thoracic Myelopathy Caused by Concurrent Beak-Type Ossification of the Posterior Longitudinal Ligament and Ligamentum Flavum at T1-T2 Level: A Case Report.

BACKGROUND: Upper thoracic myelopathy caused by combined ossification of the posterior longitudinal ligament (OPLL) and ossification of the ligamentum flavum (OLF) is relatively rare. This clinical condition is difficult to treat, and a surgical method has not been fully established. We report an extremely rare case of severe thoracic myelopathy caused by concurrent beak-type OPLL and OLF at T1-T2. CASE DESCRIPTION: A 53-year-old woman with paresthesia of both legs and an inability to hold a standing position presented to our hospital. Radiological images showed a large beak-type OPLL at T1-T2 and an OLF at T1-T7. The spinal cord was severely compressed at T1-T2. First, posterior decompression and instrumentation fusion at C6-T4 was performed, with a T1-T2 bilateral parallel gutter along the dural tube into the vertebral bodies covering the extent of the OPLL. Second, anterior decompression of the OPLL with corpectomy of T1-T2 and fusion using iliac bone grafting was performed after the sternal manubrium splitting approach. In the deep operating field of the second surgery, the gutters created during the first surgery were helpful for judging the width and thickness of the OPLL during the anterior decompression procedure. Postoperatively, her neurological symptoms greatly improved, the patient could walk independently, and the Japanese Orthopaedic Association score had improved from 3 preoperatively to 8 at the final follow-up examination at 16 months postoperatively. CONCLUSIONS: Two-stage circumferential decompression and fusion surgery can be considered an effective surgical method for upper thoracic concurrent OPLL and OLF. The bilateral gutters created during the first surgery improved the safety and feasibility of this difficult operation.

Early administration of fibrinogen concentrates improves the short-term outcomes of severe pelvic fracture patients.

Aim: Hemorrhage from pelvic fracture is a major cause of mortality after blunt trauma. Several studies have suggested that early fibrinogen supplementation improves outcomes of traumatic hemorrhage. Thus, we revised our massive transfusion protocol (MTP) in April 2013 to include early off-label administration of fibrinogen concentrate. The objective of this study was to evaluate the impact of the revision on the short-term outcomes of pelvic fracture patients. Methods: This was a single-center, retrospective, cohort study. A total of 224 consecutive pelvic fracture patients hospitalized in Saitama Medical Center (Saitama, Japan), 115 before the revision (Group E) and 109 after (Group L), were enrolled. Characteristics of the patients were compared between the groups. Impacts of the revision were evaluated by hazard ratios adjusted for characteristics, injury severity, and coagulation status using Cox's multivariate proportional hazard model. The impact was also evaluated by log-rank test and relative risk of 28-day mortality between the groups. Results: The characteristics were equivalent between the groups. The multivariate analysis revealed that the revision of MTP was significantly related to improved survival with an adjusted hazard ratio (95% confidence interval) of 0.45 (0.07-0.97). The log-rank test gave χ2-test values of 5.2 (P = 0.022) and 6.7 (P = 0.009), and the relative risks were 0.37 (0.15-0.91) and 0.33 (0.13-0.84), in patients with all Injury Severity Scores and Injury Severity Score ≥21, respectively. Conclusion: The revision of MTP to include aggressive off-label treatment with fibrinogen concentrate was related to improved short-term outcomes of severe pelvic fracture patients. However, due to the limitations of the study, the improvement could not be attributed totally to the revision.

A case series of pelvic fracture patients who developed lower urinary tract symptoms after transarterial embolization of bilateral internal iliac arteries.

Cases: Transarterial embolization of bilateral internal iliac arteries (TAE) is a useful hemostatic method for the management of pelvic fracture patients, but its effects on urinary functions remain unclear. In this study, we evaluated the impact of TAE on lower urinary tract symptoms (LUTS) in 10 pelvic fracture patients. Outcomes: Lower urinary tract symptoms before and after hospitalization were evaluated by International Prostate Symptoms Score, Overactive Bladder Symptoms Score, and Quality Of Life score. All scores showed significant worsening. The changes did not correlate with sex, age, injury severity score, or durations of unstable hemodynamics or urethral catheterization. Changes of International Prostate Symptoms Score and Quality Of Life score showed significant positive correlations with intervals between the evaluations. Conclusion: Pelvic fracture patients treated with TAE showed significant worsening of LUTS. Risk for exacerbation of LUTS should be taken into consideration when deciding to use TAE.

Membranous tracheal stenosis in a patient with anorexia nervosa and self-induced vomiting- challenges in securing the airway.

We report a rare case of acquired membranous tracheal stenosis in a patient with anorexia nervosa and a history of self-induced vomiting, but without a history of tracheal intubation or tracheostomy. A 50-year-old woman presented with difficulty in breathing and swallowing, self-expectoration, and impaired consciousness due to acute benzodiazepine intoxication. Bronchoscopic examination was performed after tracheotomy and placement of a tracheostomy tube failed to secure her respiratory tract and ventilation continued to deteriorate. A flap-like membranous structure was identified on the posterior tracheal wall, obstructing the tracheostomy tube. Physical compression of the membranous structure improved ventilation. Bronchoscopic examination is generally recommended prior to performing tracheostomy in patients suspected to have post-intubation tracheal obstruction. Based on our findings, we suggest that these examinations should also be performed in patients with conditions associated with chronic irritation of the respiratory tract, including those with a prolonged history of self-induced vomiting.