Are bedside features of shock reproducible between different observers?

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Otieno H, Were E, Ahmed I, Charo E, Brent A, Maitland K. Arch Dis Child 2004;89:977-9.

Context Shock is often underreported in children attending hospitals in developing countries. Readily obtainable features of shock are used to help management in the assessment of critically ill children. However, data are lacking on their validity.

Objective To examine the interobserver reproducibility of bedside clinical features of shock.

Design A prospective study comparing four clinical assessments. The agreement was evaluated with Cohen kappa (κ).

Setting District hospital on the coast of Kenya, Africa.

Participants One hundred consecutive pediatric admissions. The study group age ranged from 2 days to 10 years, 11 months.

Main outcome measures Capillary refill time in seconds (1, 2, 3, 4, or more), temperature gradient (yes or no), pulse volume (weak or absent, normal, strong/bounding), decreased skin turgor (yes or no), sunken eyes (yes or no), and dry mucous membranes (yes or no).

Results The interobserver agreement on the signs of shock between four clinicians was capillary refill time (combined) (κ=0.42; 95% CI, 0.34 to 0.62); temperature gradient in the upper limb (κ=0.57; 95% CI, 0.42 to 0.72) and lower limb (κ=0.62; 95% CI, 0.47 to 0.72); pulse volume weak (κ=0.40; (95% CI, 0.28 to 0.52) or normal (κ=0.30; 95% CI, 0.19 to 0.41); dehydration for dry mucous membranes (κ=0.39; 95% CI, 0.27 to 0.51); decreased skin turgor (κ=0.55; (95% CI, 0.40 to 0.70); and sunken eyes (κ=0.34; 95% CI, 0.23 to 0.45).

Conclusions In developing countries, a culture of early recognition of compensated shock and the institution of simple, potentially life-saving treatments may improve the outcome. This study provides reasonable evidence of the reproducibility of some bedside clinical features used in the assessment of shock, particularly lower limb temperature gradient and delayed capillary refill >4 seconds.

Comment Pediatricians treating critically ill newborn infants, infants, and children are faced with different degrees and causes of shock, making shock one of the most common life-threatening conditions encountered. Delay in recognizing and treating a state of shock may result in a progression from reversible shock to multiple system organ failure to death. The usefulness of any clinical sign is determined both by its ability to detect a condition and by its reproducibility among different observers. The authors of this study have tried to provide information on reliable bedside features of shock and assess the interobserver variability of such signs. Otieno et al report moderate agreement for most features of cardiovascular compromise but substantial agreement only for temperature gradient. Unfortunately, there is no assessment of more objective signs such as the presence of tachycardia, blood pressure under the 5^th percentile for age, and urinary output, all of which are early and inexpensive signs used to assess circulatory redistribution.

Newborn infants, infants, and children have developmental differences in cardiovascular response, oxygen consumption, hormonal responses, and glycogen metabolism that can alter the presentation of shock. However, the authors of the present work did not stratify their patients by age, and this limits the extrapolation over all age groups and limits the power of clinical agreement by age, especially between newborn infants and infants. These limitations are even more important when, as in the present article, 22% and 18% of the children present undernourished or in a severe state of malnutrition. The authors state that there was no significant difference in the κ values after stratification for the presence or absence of malnutrition, but the sample size is relatively small. In addition, insufficient evidence exists regarding the ability to recognize compensated shock by using clinical signs and on the physiologic responses to shock in groups of malnourished children.

Initial triage and emergency treatment are poor in hospitals, including teaching hospitals, in many developing countries. Inadequate clinical training and absence of management standards have been identified as contributory factors. However, in poor areas of the world, clinical assessment is often the sole determinant of the treatment of critically ill children. The information supporting the robustness of the clinical signs of shock is lacking in both the developed and the developing worlds. In view of these results, pediatricians surely require further definitive studies worldwide.