When should you not take your oral temperature?

2 Tachypnea

Tachypnea reduces the oral temperature reading about 0.5° C for every 10 breaths/minute increase in the respiratory rate.15,16 This phenomenon probably explains why marathon runners, at the end of their race, often have a large discrepancy between normal oral temperatures and high rectal temperatures.17

In contrast, the administration of oxygen by nasal cannula does not affect oral temperature.18

3 Cerumen

Cerumen lowers tympanic temperature readings by obstructing the radiation of heat from the tympanic membrane.5

4 Hemiparesis

In patients with hemiparesis, axillary temperature readings are about 0.5°C lower on the weak side compared with the healthy side. The discrepancy between the two sides correlates poorly with the severity of the patient’s weakness, suggesting that it is not due to difficulty holding the thermometer under the arm, but instead to other factors, such as differences in cutaneous blood flow between the two sides.19

5 Mucositis

Oral mucositis, a complication of chemotherapy, increases oral readings on average by 0.7°C,20 even without fever. This increase in temperature likely reflects inflammatory vasodilation of the oral membranes.

Temperature

Temperature should be monitored orally, if possible. The thermometer, sterilized and shaken down, is placed under the tongue of the patient, who should not eat, smoke, or drink anything 10 minutes before the recording. The thermometer remains in the closed mouth for 2 minutes before removal. Disposable thermometers and digital thermometers (Figure 2-20) have become popular, accurate, and commonplace today.

Guidelines for clinical evaluation.

The “normal” oral temperature of 37.0° C (98.6° F) is only an average. The true range of normal is considered to be from 36.11° C to 37.56° C (97° F to 99.6° F). Temperatures vary during the day (from 0.5° F to 2.0° F), with the lowest in the early morning and highest in the late afternoon.

Fever represents an increase in temperature beyond 37.5° C (99.6° F). Temperatures in excess of 38.33° C (101° F) usually indicate the presence of an active disease process. Evaluation of the cause of the fever is necessary before treatment. When dental or periodontal infection is considered to be a probable cause of elevated temperature, immediate treatment (e.g., incision and drainage [I & D], pulpal extirpation, or extraction) and antibiotic and antipyretic therapy are indicated. If the patient's temperature is 40.0° C (104° F) or higher, pretreatment medical consultation is indicated. The planned treatment, especially any treatment involving the administration of CNS depressants, should be postponed, if possible, until the cause of the elevated temperature is determined and treated.

IV. Evaluation of the Febrile Response

A.

Temperature

Normal oral temperature: 37°FC (98.6°FF)

Diurnal variation: 1.3°FC (2.4°FF) greatest from 4 to 6 PM

Core temperature is 0.5°FC (0.9°FF) higher than oral temperature.

Fever: temperature >38.0°FC (100.4°FF)

Temperatures run higher in burn patients, and at Parkland Memorial Hospital we routinely treat patients with temperatures >39.5°FC as fever in burn patients.

Vital signs

Heart rate increases approximately 5 to 10 bpm/°FC

Hypotension associated with advanced sepsis/SIRS

Tachypnea manifests as respiratory rate >20

Physical examination

Neurologic

Decreased level of consciousness

Focal neurologic deficit

Head, eye, ear, nose, and throat (HEENT)

Facial tenderness

Nuchal rigidity

Nasal/sinus drainage

Lungs

Abnormal breath sounds

Cardiac

Murmur

Pericardial friction rub

Sternal instability (after cardiac surgery)

Abdomen

Abdominal tenderness

Mass

Distention

Bowel sounds

Rectal

Perirectal mass/tenderness

Skin/soft tissue

Erythema, tenderness, swelling, heat

Line sites

Extremities

Take down casts/splints to inspect skin.

Lower extremity edema (e.g., deep venous thrombosis)

Hematology (CBC)

WBC increased; may be decreased with overwhelming infection

Left shift or bandemia with infection

Thrombocytopenia sometimes associated with sepsis

Cultures (before initiation of antibiotic therapy)

Obtain two sets of peripheral blood cultures.

Obtain blood culture from each central line unless placed more than 48 hours prior.

Obtain cerebrospinal fluid, bronchial washings, wound cultures as indicated.

Urinalysis

Urinalysis looking for WBCs, nitrite, and leukocyte esterase

Urine culture

Chest x-ray

Infiltrate, with signs of infection suggestive of pneumonic process

Effusion (parapneumonic, sympathetic)

Air-fluid level suspicious for lung abscess

Subdiaphragmatic air is a sensitive indicator of hollow visceral perforation but a normal variant in post-celiotomy period.

Computed tomography (CT)

Suspicious for intra-abdominal process/abscess

Obtain 8 to 10 days postoperatively after abdominal surgery

Some patients will be too unstable to go to CT.

Bedside surgeon-performed ultrasound

When available, may detect presence of lower extremity deep venous thrombosis

Clinical Presentation

PID is diagnosed clinically and providers should maintain a low threshold for diagnosis and treatment. Laparoscopy may be used to obtain a more definitive diagnosis, but it is often not readily available. The presentation almost always includes a report of lower abdominal pain and may include vaginal discharge, dysuria, abnormal vaginal bleeding, nausea and vomiting, and dyspareunia. The CDC suggests that, in the absence of other explanation, diagnosis and treatment for PID should be made in the context of uterine/adnexal tenderness or cervical motion tenderness.

Additional CDC criteria that support a diagnosis of PID include the following:

Oral temperature above 101°F (38.3 °C)

Abnormal cervical or vaginal mucopurulent discharge

Presence of white blood cells on saline microscopy of vaginal secretions

Elevated erythrocyte sedimentation rate

Elevated C‐reactive protein

Laboratory documentation of cervical infection with N. gonorrhea or C. trachomatis

The most specific criteria for diagnosing PID include the following:

Endometrial biopsy with histopathologic evidence of endometritis

Transvaginal sonography or MRI techniques showing thickened, fluid‐filled tubes with or without free pelvic fluid or tubo‐ovarian complex

Laparoscopic abnormalities consistent with PID

Febrile Neutropenia

Febrile Neutropenia (FN) is defined by the following criteria:

A single oral temperature ≥38.3°C (101.0°F) or an oral temperature ≥38.0°C (100.4°F) sustained for >1 h or that occurs twice within a 24-h period.

An ANC <0.5×109/l or ANC <1.0×109/l expected to decrease to <0.5×109/l over the subsequent 48 h.

Families should be advised against taking rectal temperatures. Recent consumption of hot or cold beverages should not alter management if the patient has had a documented oral temperature taken. Alternate routes for fever measurement, including axillary, otic, and temporal, should be discouraged but all should be managed in the same manner if there is a documented fever.

Initial FN evaluation should include the following:

Complete blood count with differential.

Complete metabolic panel.

Blood cultures from each lumen of the CVC or peripheral cultures if without a CVC (≥1 ml of blood).

Clean-catch bacterial urine cultures (urine catheterization should not be done, especially in the neutropenic patient).

Gram stain and culture from suspicious skin, oropharyngeal, or CVC sites.

Additional measures that may be considered but are not routinely recommended include:

Peripheral blood cultures in addition to central cultures can be considered as a means to determine bacteremia versus CVC infection based on the differential time to positivity, although the impact of this measure on treatment decision-making in FN is unclear.

Coagulation studies in the patient with bleeding.

Chest radiography is not routinely recommended and should only be done in the patient with respiratory compromise, symptoms of pulmonary infection, or auscultatory signs.

Patients with sinus tenderness should have computed tomography (CT) of the sinuses.

Patients with esophagitis should be considered for endogastroduodenoscopy with biopsy and culture to rule out viral and fungal causes.

Patients with diarrhea should have a stool sample sent for culture, rotavirus, and Clostridium difficile testing.

Lumbar puncture is rarely indicated but if the patient has central nervous system (CNS) signs a head CT should be performed first to rule out mass lesions or hemorrhagic stroke which may lead to increased intracranial pressure.

Shunt fluid examination from implanted devices such as VP shunts or Ommaya reservoirs is rarely indicated.

Impression Waxes and Natural Resins

A second group of thermoplastic impression materials consists of those impression waxes and resins commonly spoken of as mouth-temperature waxes. The most familiar of these have been the Iowa wax (Kerr Co., Romulus, MI) and the Korecta waxes (D-R Miner Dental, Concord, CA), all of which were developed for specific techniques.

Knowledge of the characteristics of mouth-temperature waxes is important if they are to be used correctly.

The Iowa wax was developed for use in recording the functional or supporting form of an edentulous ridge. It may be used as a secondary impression material or as an impression material for relining the finished removable partial denture to obtain support from the underlying tissues. The mouth-temperature waxes lend themselves well to all relining techniques as they will flow sufficiently in the mouth to avoid displacement of tissues. As with any relining technique, it is necessary that sufficient relief and venting be provided to give the material the opportunity to flow.

The difference between impression wax and modeling plastic is that impression waxes have the ability to flow as long as they are in the mouth and thereby permit equalization of pressure and prevent displacement. The modeling plastics flow only in proportion to the amount of flaming and tempering that can be done outside of the mouth; this does not continue after the plastic has approached mouth temperature. The principal advantage of mouth-temperature waxes is that, given sufficient time, they permit a rebound of those tissues that may have been forcibly displaced.

The impression waxes also may be used to correct the borders of impressions made of more rigid materials, thereby establishing optimum contact at the border of the denture. All mouth-temperature wax impressions have the ability to record border detail accurately and include the correct width of the denture border. They also have the advantage of being correctable.

Mouth-temperature waxes vary in their working characteristics. They are designed primarily for impression techniques that attempt to record the tissues under an occlusal load. In such techniques, the occlusion rim or the arrangement of artificial teeth is completed first. Mouth-temperature wax is then applied to the tissue side of the denture base, and the final impression is made under functional loading by using various movements to simulate functional activity. These mouth-temperature materials also may be used successfully in open-mouth impression techniques. Iowa wax will not distort after removal from the mouth at ordinary room temperatures, but the more resinous waxes must be stored at much lower temperatures to avoid flow when they are out of the mouth. Resinous waxes are not ordinarily used in removable partial denture impression techniques except for secondary impressions.

Physical examination

The physical portion of the examination includes the vital signs: resting blood pressure, pulse rate, oral temperature and respiration rate. The vascular status and neurologic assessment are equally important and should be carefully measured prior to surgery. All patients undergoing surgery should routinely have this work-up performed. This information is essential in establishing the current patient health status and it may also expose some unknown primary medical condition that will require referral to the primary care provider.

The cutaneous condition should be re-examined, measured, photographed and documented in the chart during the physical examination. The extent of the proposed procedure may suggest the need for further diagnostic or preoperative laboratory evaluations, X-rays, magnetic resonance imaging (MRI) scans or special studies. In cases where there is a known preoperative medical condition or history of bleeding problems, it is advisable to obtain a complete blood count including: measurement of platelet count, a prothrombin time, INR (international normalized ratio) and partial thromboplastin time. With infected or ulcerated lesions a preoperative culture of the wound may be helpful in determining the source of the infection. It is usually not necessary to perform other laboratory evaluations before cutaneous surgery.

When should you not use an oral thermometer?

Who should not have their temperature taken orally?

What can affect an oral temperature reading?

What special precautions would you follow for checking oral temperature?