A mixed methods analysis of caller-emergency medical dispatcher communication during 9-1-1 calls for out-of-hospital cardiac arrest

OBJECTIVE

Recognition of out-of-hospital cardiac arrest (OHCA) during 9-1-1 calls is critically important, but little is known about how laypersons and emergency medical dispatchers (EMDs) communicate. We sought to describe 9-1-1 calls for OHCA.

METHODS

We performed a mixed-methods, retrospective analysis of 9-1-1 calls for OHCA victims in a large urban emergency medical services (EMS) system using a random sampling of cases containing the term "cardiopulmonary resuscitation" (CPR) in the EMS electronic report. A constant comparison qualitative approach with four independent reviewers continued until thematic saturation was achieved. Quantitative analysis employed computational linguistics. Callers' emotional states were rated using the emotional content and cooperation score (ECCS).

RESULTS

Thematic saturation was achieved after 46 calls. Three "OHCA recognition" themes emerged [ 1) disparate OHCA terms used, 2) OHCA mimics create challenges, 3) EMD questions influence recognition]. Three "CPR facilitation" themes emerged [ 1) directive language may facilitate CPR, 2) specific instructions assist CPR, 3) caller's emotions affect CPR initiation]. Callers were generally "anxious but cooperative." Callers saying "pulse" was associated with OHCA recognition.

CONCLUSION

Communication characteristics appear to influence OHCA recognition and CPR facilitation.

PRACTICE IMPLICATIONS

Dispatch protocols that acknowledge characteristics of callers' communication may improve OHCA recognition and CPR facilitation.

Identifying Key Words in 9-1-1 Calls for Stroke: A Mixed Methods Approach

OBJECTIVES

Identifying stroke during a 9-1-1 call is critical to timely prehospital care. However, emergency medical dispatchers (EMDs) recognize stroke in less than half of 9-1-1 calls, potentially due to the words used by callers to communicate stroke signs and symptoms. We hypothesized that callers do not typically use words and phrases considered to be classical descriptors of stroke, such as focal neurologic deficits, but that a mixed-methods approach can identify words and phrases commonly used by 9-1-1 callers to describe acute stroke victims.

METHODS

We performed a mixed-method, retrospective study of 9-1-1 call audio recordings for adult patients with confirmed stroke who were transported by ambulance in a large urban city. Content analysis, a qualitative methodology, and computational linguistics, a quantitative methodology, were used to identify key words and phrases used by 9-1-1 callers to describe acute stroke victims. Because a caller's level of emotional distress contributes to the communication during a 9-1-1 call, the Emotional Content and Cooperation Score was scored by a multidisciplinary team.

RESULTS

A total of 110 9-1-1 calls, received between June and September 2013, were analyzed. EMDs recognized stroke in 48% of calls, and the emotional state of most callers (95%) was calm. In 77% of calls in which EMDs recognized stroke, callers specifically used the word "stroke"; however, the word "stroke" was used in only 38% of calls. Vague, non-specific words and phrases were used to describe stroke victims' symptoms in 55% of calls, and 45% of callers used distractor words and phrases suggestive of non-stroke emergencies. Focal neurologic symptoms were described in 39% of calls. Computational linguistics identified 9 key words that were more commonly used in calls where the EMD identified stroke. These words were concordant with terms identified through qualitative content analysis.

CONCLUSIONS

Most 9-1-1 callers used vague, non-specific, or distractor words and phrases and infrequently provide classic stroke descriptions during 9-1-1 calls for stroke. Both qualitative and quantitative methodologies identified similar key words and phrases associated with accurate EMD stroke recognition. This study suggests that tools incorporating commonly used words and phrases could potentially improve EMD stroke recognition.

Enhancing Community Disaster Resilience Through Mass Sporting Events

Disaster response requires rapid, complex action by multiple agencies that may rarely interact during nondisaster periods. Failures in communication and coordination between agencies have been pitfalls in the advancement of disaster preparedness. Recommendations of the Federal Emergency Management Agency address these needs and demonstrate commitment to successful disaster management, but they are challenging for communities to ensure. In this article we describe the application of Federal Emergency Management Agency guidelines to the 2008 and 2009 Chicago Marathon and discuss the details of our implementation strategy with a focus on optimizing communication. We believe that it is possible to enhance community disaster preparedness through practical application during mass sporting events.

(Disaster Med Public Health Preparedness. 2011;5:310–315)

Histologic evaluation of retrieved craniofacial implants

A retrieval study was performed on implants placed extraorally in the craniofacial region. The study included 19 implants retrieved from 16 patients. The implants were all stable at the time of removal. For various reasons, 5 of the implants were never loaded, whereas 14 of the implants had a known loading period of 3 months to 7 years 7 months. The reasons for removal varied but included the following: death in 1 case; poor results of the bone-anchored hearing aid in 7 cases; host-related reasons, varying from soft tissue irritation to infection or pain, in 6 cases; change of treatment plan in 1 case; and scheduled direct removal at the time of insertion in 1 case. The results of the histologic evaluation were similar to those reported in retrieval studies of a corresponding design used intraorally.

Airway obstruction in children due to plexiform neurofibroma of the larynx

Plexiform neurofibroma of the larynx is a rare disease. Three cases in children with airway obstruction are presented. After tumour reduction via a lateral pharyngotomy their tracheostomies could be closed. The surgical treatment of plexiform neurofibroma of the superior laryngeal nerve is discussed and conservative, subtotal resection is recommended.

Eustachian tube function in ears with cholesteatoma

Eustachian tube (ET) function was measured before and after surgery in patients with acquired cholesteatoma. The cholesteatoma group and a group of patients without cholesteatoma but with dry tympanic membrane perforations (TM-Perf) were compared in this respect. ET function was measured by the air pressure equalization technique; if necessary, a transmyringeal tube was inserted to establish direct communication between the external ear canal and the middle ear cleft. No difference in ET function was found before and after surgery in the cholesteatoma group. The ET testing results in the cholesteatoma group were inferior to those in the group with TM-Perf. These findings are discussed in relation to proper surgical procedure in ears with cholesteatoma.

Acute traumatic tympanic membrane perforations. Cover or observe?

The influence of a paper prosthesis on healing in acute traumatic tympanic membrane perforations was studied in 60 patients randomly selected for a treatment group or a control group. The majority (42 [70%] ) were seen within two days. All patients were treated with oral antibiotics for ten days. The overall healing rate two months after the trauma was 94% (37 of 39 patients). No significant difference between the study group and the control patients was observed. Intermittent secretion was seen in six patients but did not influence the outcome. The perforations occurred in patients with normally sized mastoid air cell systems as seen on roentgenograms. We conclude that acute traumatic tympanic membrane perforations do not need to be treated routinely with paper patching.

Survival after surgical treatment in maxillary neoplasms of epithelial origin

During 1968-1979, 55 cases of epithelial neoplasms originating from the maxillary antrum were diagnosed and treated within the referral area of 1.5 million inhabitants. A majority of the patients were operated upon after pre-operative irradiation therapy (40-50 Gy). No significant difference in survival rate was found between patients operated on by total maxillectomy, including orbital exenteration, and patients subjected to partial maxillectomy. Patients with tumours not completely removed during primary surgery and patients with glandular involvement had a poor prognosis despite additional surgery and radiotherapy. The prognosis for the remaining patients was considerably better, with a 5-year survival rate of 60 per cent.

Eustachian tube function and healing after myringoplasty

The function of the eustachian tube (ET) was measured preoperatively among patients with dry, chronic, tympanic membrane perforations. Tympanograms were obtained 1 to 2 years postoperatively. A significantly better healing rate was found in the group classified as "good" ET-function. Also, a significantly greater number of tympanograms with no deflections were found in the "bad" ET-function group. Thus, the ET-testing allows an identification of patients who must be followed up with extra care during the postoperative period, in order that complications such as reperforation of the tympanic membrane may be avoided.

Mastoid volume and eustachian tube function in ears with cholesteatoma

Eustachian tube function, as measured by the pressure equalizing technique, and the mastoid air cell area were compared among ears with traumatic eardrum perforations, ears with chronic otitis media, and cholesteatomatous ears. A statistically significant difference among the three groups was found regarding the residual positive pressure after swallowing, with the poorest function found in the cholesteatoma group. Also, the ability to reduce a negative pressure was found to be inferior in the cholesteatoma group compared with the others. The mean mastoid air cell area measured on the x-ray film was smallest among ears with cholesteatoma and differed significantly among the groups. These disturbances in the active eustachian tube function as well as the volume of the middle ear cleft, including the mastoid air cell system, were found to be characteristic among ears with acquired cholesteatomas.

Clinical experience with the bone-anchored hearing aid

Patients operated on for chronic otitis media sometimes have problems with persistent discharge from the ear when using a conventional hearing aid with an ear mould located in the ear canal. A new technique where a hearing aid for bone-conducted sound is mounted on an osseointegrated titanium screw located in the mastoid area is available. The method was evaluated in a routine clinical setting outside the centre of development. Eight patients were fitted with the new hearing aid. All improved regarding the drainage from the ears. The patients were all very satisfied with the hearing results and with the hearing aid, from a practical as well as from a cosmetic point of view. No complications were noted during an observation period of minimum 12 months.

Diagnostic considerations of tongue-base malignancies

Forty-two patients with malignancies localized to the base of the tongue were treated at Sahlgrenska Hospital between 1971 and 1980. These patients were re-analyzed with respect to symptomatology and clinical outcome. Pain in the mouth, throat, and ears as well as swallowing difficulties were the most frequent overt symptoms of disease. In general, patients experienced symptoms for at least 3 months before a positive tumor diagnosis was made. In all, 75% of the patients were found to have large tumors which extended beyond the base of the tongue. Most of the patients were treated with irradiation. The overall 3-year survival rate was 28%, while individual patient survival was related to the size of the primary tumor and to the occurrence of lymph node metastases. Careful attention to symptomatology may reduce delays in establishing an accurate diagnosis and consequently improve the prognosis for patients with these cancers.

The elongated styloid process as a cause of throat discomfort. Four case reports

Pain in the neck, radiating towards the ear, together with a foreign body sensation in the throat is a common complaint. A less common finding upon physical examination is an elongated styloid process, palpable in the tonsillar fossa and provoking the symptoms for which the patient is seeking medical advice. The diagnosis of this so-called Eagle's syndrome is described and the case history and treatment of four patients are presented.

Ear drum mobility and middle ear volume measured with tympanometry

Tympanometry was evaluated as a measure of the volume of the air-containing space of the middle ear cleft as well as of tympanic membrane displacement in persons with intact tympanic membranes. Static compliance reduced with compliance of ear canal volume at -400 mm H2O, was determined with 0.22 kHz probe tone frequency. Further the difference in compliance obtained at +/- 400 mm H2O was regarded as a measure of ear drum mobility. The volume of the middle ear cleft including the mastoid air cell system was measured indirectly by X-ray of the ear in a lateral projection. No relation was found to exist between static compliance and mastoid air cell area measured on the X-ray film. Nor was there any relation found between ear drum mobility measured with tympanometry and size of the mastoid air cell system.

Size of the mastoid air cell system obtained with two types of X-ray equipment

The first systematically performed study concerning the size variation of the mastoid air cell system was measured on the X-ray film in a lateral projection, as exposed on the skull table. A new type of equipment (Orbix) with an isocentric motion of the roentgen tube and the film cassette and a different magnification, is gradually replacing the skull table. Temporal bone specimens were examined in a lateral projection using both equipments. The area of the mastoid air cell system was measured with a planimeter. A significant correlation was found between the areas obtained with the two techniques.

Volume measurement of middle ear and mastoid air cell system with impedance audiometry on patients with eardrum perforations

The usefulness of the electroacoustic impedance bridge with a probe tone frequency of 0.22 kHz in the determination of the middle ear and mastoid volumes was evaluated in patients with dry eardrum perforations. The values obtained were compared with the volumes determined by an aspiration technique utilizing the gas laws. Also, a comparison was made between the impedance volumes and the size of the mastoid air cell system as measured on x-ray film in a lateral projection. A significant agreement between the two methods of direct volume determination was found. A good relationship was found between the impedance volume and the mastoid air cell area. The impedance audiometry enables a rapid and valuable estimation of the air reservoir in the middle ear in patients with eardrum perforations.

The size of the mastoid air cell system among black and white children with middle ear effusion

The incidence of middle ear disease among black American children is lower than among white children. Many factors may contribute to this difference. The possibility of an anatomical variation regarding the cellularity of the mastoid process was investigated. The size of the mastoid air cell system was measured in black and white children with and without middle ear effusion. A significantly smaller mastoid air cell system was found in the groups with middle ear disease compared to those without disease. No difference between white and black children in diseased as well as non-diseased ears could be demonstrated.

Measurement of middle ear volume using the impedance audiometer

Ears with chronic otitis media are characteristically associated with small mastoid air cell systems. This also indicates a small air volume in these ears, which may influence the pathophysiology and course. Therefore, it may be important to get a measure of the air volume in the middle ear mastoid air cell system. Conventional mastoid X-ray investigations have so far been used for estimating this volume. As impedance audiometry has gained in popularity during recent years, it has been postulated that this tool may be useful for measuring the volume in the middle ear and the mastoid system. In this report we present data comparing the acoustically measured size to direct volumetric and planimetric size of the mastoid air cell system on the X-ray film. Temporal bone specimens with perforation of the tympanic membrane have been investigated. A good correlation between these methods is obtained, and we conclude that impedance audiometry enables a rapid and valuable estimation of the air reservoir in the middle ear.

Middle ear effusion among children after acute otitis media. A diagnostic problem

Acute suppurative otitis media is a common childhood disease. A frequent complication is a non-purulent middle ear effusion. The diagnosis of this disturbance is by no means simple. The sensitivity and the specificity of tympanometry, stapedial reflex measurement and audiometric pure tone screening at two frequencies were compared to the oto-microscopic findings in a follow-up study among children treated for acute suppurative otitis media. Tympanometry with a pressure limit of -100 mm H2O can be used as a simple screening procedure after the initial treatment to help select those patients requiring further treatment.

Value of serial measurement of serum angiotensin converting enzyme in the management of sarcoidosis

Serial serum samples from 35 patients with histologically proved sarcoidosis were measured for angiotensin converting enzyme activity. The serum angiotensin converting enzyme (SACE) activity was compared with the clinical activity of sarcoidosis. In both the treated and untreated group, the SACE activity closely paralleled the clinical status. There was agreement between SACE index and clinical index in 81 of 101 paired observations. It appears that SACE activity is a good reflection of granulomatous activity in sarcoidosis. Once the decision has been made to treat sarcoidosis, serial SACE determinations are helpful in monitoring the dose and duration of therapy with corticosteroids.

Size of the mastoid air cell system in children with middle ear effusion

The mastoid air cell system probably functions as an air reservoir. Among adults with chronic otitis media a small mastoid air cell system is prevalent In cases of chronic nonpurulent middle ear effusion among children, the reports have been contradictory concerning the size of the mastoid air cell system. In the present investigation, white children with long-standing problems of middle ear effusion have been examined by means of X-rays of the mastoid process in the lateral projection and the size of the air cell system measured by planimetry. The size of the air cell system was found to be significantly smaller in comparison with normal white children.