Israel Medical Association Journal

Background: Interpretation of blood gases is essential for the correct practice of medicine. Normal ranges for arterial blood gases (ABG) have not been extensively studied in the older population. Also, venous blood gases and venous-arterial pCO₂ gradient have not been studied in this population, even though they signify the majority of hospitalized patients.

Objectives: To determine the normal range for ABG and the bias limits of agreement for arterial-venous difference in the elderly population.

Methods: We recruited 130 elderly patients (> 70 years) and obtained blood gas measurements from venous and arterial blood. Patients were divided into four categories: healthy patients, patients with stable chronic pulmonary disease, hospitalized patients with acute respiratory illness, and hospitalized patients without respiratory disease. Samples were analyzed in a point of care analyzer.

Results: Mean PaCO₂ was 36.9 ± 4.2 mmHg for the healthy control group, 37.0 ± 4.8 mmHg in the stable chronic respiratory group, 37.0 ± 5.0 mmHg in the non-respiratory hospitalization group, and 42.3 ± 11.4 mmHg for the respiratory hospitalization group, Kruskall-Wallis, P <0.0025. Mean bias between venous and arterial CO₂ was +10.0 mmHg with 95% limits of agreement between 2.7 mmHg and -22.8 mmHg.

Conclusions: In elderly patients, the range of PaCO₂ measurements was similar to the accepted normal range in clinical practice. Venous-arterial PCO₂ gradient had high bias and wide limits of agreement, similar to previously published studies.

Background: The DES-obstructive sleep apnea (DES-OSA) score uses morphological characteristics to predict the presence and severity of obstructive sleep apnea syndrome (OSAS).

Objectives: To validate DES-OSA scores on the Israeli population. To identify patients requiring treatment for OSAS. To evaluate whether additional parameters could improve the diagnostic value of DES-OSA scores.

Methods: We performed a prospective cohort study on patients attending a sleep clinic. Polysomnography results were examined independently by two physicians. DES-OSA scores were calculated. STOP and Epworth questionnaires were administered, and data on cardiovascular risk was extracted.

Results: We recruited 106 patients, median age 64 years, 58% male. DES-OSA scores were positively correlated with apnea-hypopnea index (AHI) (P < 0.001) and were significantly different between the OSAS severity groups. Interobserver agreement for calculating DES-OSA was very high between the two physicians (intraclass correlation coefficient 0.86). DES-OSA scores ≤ 5 were associated with high sensitivity and low specificity (0.90 and 0.27, respectively) for moderate to severe OSAS. In univariate analysis, only age was significantly correlated with the presence of OSAS (OR 1.26, P = 0.01). Age older than 66 years as a single point in the DES-OSA score slightly improved the sensitivity of the test.

Conclusions: DES-OSA is a valid score based solely on physical examination, which may be useful for excluding OSAS requiring therapy. DES-OSA score ≤ 5 effectively ruled out moderate to severe OSAS. Age older than 66 years as an extra point improved the sensitivity of the test.

Background: Studies in lung transplantation demonstrate that the ancestry and gender dissimilarities of donor–recipients lead to a decrease in survival of the recipient. 

Objectives: To evaluate the survival of lung transplant recipients in Israel based on whether the donors and recipients are of Jewish or Arab ancestry as well as survival based on gender match or mismatch.

Methods: We performed a retrospective observational cohort study of 345 lung transplant recipients at the Rabin Medical Center, Petah Tikva, Israel between January 1997 and January 2013. We compared the survival of lung transplant recipients in two ancestry categories: ancestry matched (Jewish donors to Jewish recipients or Arab donors to Arab recipients) and ancestry mismatched (Jewish donors to Arab recipients and vice versa). We also compared the survival among the four gender donor and recipient combinations (male to male, female to female, male to female, and female to male). 

Results: Survival analysis revealed no significant differences between the two ancestry groups (P = 0.51) and among the four gender combinations (P = 0.58). On Cox multivariate analysis, younger donor age was the only significant parameter for longer survival (hazards ratio 1.025, 95% confidence interval 1.012–1.037).

Conclusions: Gender and ancestry mismatches in these two Israeli populations do not appear to alter the clinical outcomes following lung transplantation.