Robert A. Barish

Confirmation of the Pulse Oximetry Gap in Carbon Monoxide Poisoning

STUDY OBJECTIVES To demonstrate the degree to which pulse oximetry overestimates actual oxyhemoglobin (O2Hb) saturation in patients with carbon monoxide (CO) poisoning. This phenomenon has been reported in fewer than 20 humans in the English medical literature. METHODS A retrospective chart review of 191 patients evaluated for CO poisoning at a regional hyperbaric center identified 124 patients 10 years of age and older who had had both arterial blood gas and pulse oximetry measurements and who had received either high-flow oxygen through a nonrebreather mask or 100% inspired oxygen through an endotracheal tube. Blood gas measurements, including direct spectrophotometric determination of O2Hb and carboxyhemoglobin (COHb) saturation values, were compared with finger-probe pulse oximetry readings. RESULTS Measured O2Hb saturation (mean +/- SD, 88.7 +/- 10.2%; range, 51.4% to 99.0%) decreased linearly and predictably with rising COHb levels (10.7 +/- 10.4%; range, .2% to 46.4%). Pulse oximetry saturation (99.2% +/- 1.3%; range, 92% to 100%) remained elevated across the range of COHb levels and failed to detect decreased O2Hb saturation. The pulse oximetry gap, defined as the difference between pulse oximetry saturation and actual O2Hb saturation (10.5% +/- 9.7%; range, 0% to 40.6%), approximated the COHb level. CONCLUSION There is a linear decline in O2Hb saturation as COHb saturation increases. This decline is not detected by pulse oximetry, which therefore overestimates O2Hb saturation in patients with increased COHb levels. The pulse oximetry gap increases with higher levels of COHb and approximates the COHb level. In patients with possible CO poisoning, pulse oximetry must be considered unreliable and interpreted with caution until the COHb level has been measured.

Prescription noncompliance: contribution to emergency department visits and cost.

We randomly surveyed 100 patients in the acute care section of a large urban university hospital Emergency Department (ED) on 6 days with regard to the existence of and reasons for prescription noncompliance. Noncompliance was considered a major factor contributing to the ED visit if: (1) no medications had been taken for at least 48 h before the ED visit; (2) the medications, when previously taken, had routinely controlled the condition for which the patient was presenting to the ED; and (3) no other significant cause or illness was believed to have precipitated the ED visit. ED, admissions, and yearly medication costs were calculated for all patients. Noncompliance was found to be a contributing factor in the cases of 22 patients (22%). The most common medications involved were phenytoin and albuterol. Cost was the most common reason for noncompliance (11 [50%]). The average ED charge per noncompliant patient discharged was

The electrocardiographic features of hypothermia

576.61. Six noncompliant patients were admitted at an average cost of

Unsuspected heterotopic pregnancy in a woman without risk factors

4,834.62. The average cost of a years medication was

The efficacy and safety of a continuous albuterol protocol for the treatment of acute adult asthma attacks

520.72. Noncompliance with drug prescriptions is a significant contributor to ED visits and health care costs.

The electrocardiographic manifestations of pulmonary embolism

Hypothermia results in the development of several characteristic electrocardiographic changes. As the core body temperature decreases, several changes in cardiac rhythm occur. Prolongation of the PR, QRS, and QT intervals are also seen. Muscle tremor artifact may be present, even in the absence of clinical shivering. A characteristic secondary deflection on the terminal portion of the QRS complex (Osborn wave) is usually found. All of these features are reversible with rewarming.

Isolated uvular angioedema associated with ACE inhibitor use

A 27-year-old woman presented to the emergency department with abdominal pain. One week prior to this she had had an ultrasound which revealed an intrauterine pregnancy (IUP). A second ultrasound performed at our institution revealed an intrauterine pregnancy along with a concomitant ectopic pregnancy which had ruptured. This case emphasizes that coincident pregnancies may occur in women who are without risk of ectopic pregnancy or multiple gestations. In addition, ultrasound must be evaluated fully for heterotopic pregnancy in all women.

ACCIDENTAL HYPOTHERMIA WITH CARDIAC ARREST: RECOVERY FOLLOWING REWARMING BY CARDIOPULMONARY BYPASS

We performed a prospective study over a 6-month period to test the efficacy and safety of a continuous nebulized albuterol protocol for the treatment of acute adult asthma attacks. All patients 18 years or older presenting to the emergency department with acute asthma attacks were begun by the triage nurse on the protocol of three continuous albuterol (2.5 mg) nebulizer treatments. Pretreatment and posttreatment peak flow, respiratory rate, pulse, and blood pressure were documented and patients gave a pretreatment and posttreatment rating of the clinical severity of their attack using a (1 to 10) visual analog scale. In addition, all adverse effects were noted. Seventy-six patients were entered in the study. The average age was 44 years (range, 20 to 82 years). Pretreatment and posttreatment peak flow, respiratory rate, pulse, blood pressure, and clinical severity were compared using the paired t test. Patients showed statistically significant increases in peak flow (128 to 292; P < .0001) and statistically significant decreases in respiratory rate (27 to 20; P < .0001); pulse, 103 to 94 (P < .0001); clinical severity, 7.8/10 to 1.8/10 (P < .0001); and blood pressure, 141/82 to 132/77 (P < .001). Adverse effects were minimal. Two patients (2.6%) felt flushed, three patients (4%) felt jittery, and one patient (1.3%) had a sensation of palpitations. We conclude that a continuous nebulized albuterol protocol is both extremely efficacious and safe for the treatment of acute adult asthma attacks.

Deep venous thrombosis of the upper extremity: Diagnosis and treatment

The electrocardiographic manifestations of pulmonary embolism include rhythm and condition disturbances and changes in the P wave, QRS complex, or T wave. Since these abnormalities are highly variable and frequently transient, they lack the sensitivity necessary to establish the diagnosis of pulmonary embolism. The electrocardiogram may rise the suspicion of pulmonary embolism, but other diagnostic tests are necessary to confirm the diagnosis.

Baseball bat assault injuries.

Angioedema is a well-known complication of medical therapy with angiotensin-converting enzyme (ACE) inhibitors. Isolated uvular angioedema, a rare presentation of angioedema, in a patient taking lisinopril (Zestril) is described in this case report. Management of uvular edema is also reviewed.