Evaluation of the Effect of Clinical Characteristics and Intensive Care Treatment Methods on the Mortality of Covid-19 Patients Aged 80 Years and Older

Sibel Oba; Mustafa Altınay; Aysel Salkaya; Hacer Şebnem Türk

Disclosures

BMC Anesthesiol. 2021;21(291) 

In This Article

Discussion

The effects of clinical characteristics and the intensive care treatment methods on the mortality of Covid-19 patients aged 80 years and older were investigated in our study. During the Covid-19 pandemic elderly patients have higher rates of intensive care admission and mortality when compared with younger patients. The course of hospitalization, intensive care therapy and outcomes of the Covid-19 patients older than 65 years of age were investigated in previous studies.[2–5] However, only a few reports have analyzed the clinical course and characteristics of Covid-19 patients aged 80 years age and older.[2,3]

In our study, mortality rate was very high (%80.5) and mortality rates among admitted patients increased as the age increased (mean age of non-survivor group was 86 vs 83 in survivor group). High levels of CRP, PCT, ferritin and having IMV are detected as poor outcome markers.

In previous studies, higher mortality risks have been reported in men than in women. Since the density of immune-related genes and regulatory elements is higher in X-chromosome, sex may influence the infectious severity of SARS-CoV-2.[8] However, in our study, despite higher number of male patients (n = 102), the mortality did not differ among genders. This can be explained by the fact that all patients were very elderly and frail.

In comparison with the recently published studies,[3,9] in our study, the duration of stay in ICU for both groups was short (mean 7 days). The reason for this comparatively short length of stay in ICU is that all patients with nasal cannula or reservoir mask were followed up in another unit in emergency department. The patients were admitted to ICU only when there was a need of intubation, HFNC and/or NIMV.

Laboratory tests were analyzed in many previous studies to determine the severity of the Covid-19 disease.[3,9] Those studies have revealed that increased levels of CRP, PCT, D-dimer, troponin I, ferritin, ALT, AST, urea, creatinine, LDH occur in the severe manifestation of the Covid-19 disease. In our study similar to the previous studies, CRP, PCT, ferritin and LDH values were statistically high (p = 0,011 p = 0,030 p = 0,002 p = 0,019) in the non-survivor group. To determine the cut-off values of the inflammatory markers we used the ROC analysis and high levels of CRP, PCT and ferritin were found as indicators of poor outcome. Higher PCT implies a more severe condition of co-infection in Covid-19 patients.

In a previous study, lymphopenia (31.4%), increased D-dimer (38.1%), depressed albumin (36.2%), elevated LDH (41.0%), and a high level of CRP (79.0%) were common among elderly patients with Covid-19.[10] In our study the albumin level of the non-survivor group was statistically significantly low (p = 0,032). D-dimer elevation is a considerable marker in worsening of the prognosis by coagulopathy and embolic incidents. In our study, D-dimer level of the non-survivor group was high even though it was not statistically significant. Li et al.[8] have shown that lymphopenia was a predictor of severe Covid-19. While the specific mechanism of lymphopenia has not been revealed, it is postulated that SARS-CoV particles targeted lymphocytes and destroyed its cytoplasmic components, thus causing a reduction of T cells. In our study, lymphocyte level of the non-survivor group was low compared to the survivor group although it was not statistically significant.

In the study published by Li et al., glucocorticoid, increased neutrophil and LDH were stated as predictive indicators for IMV.[8] Similar studies have suggested that increased level of LDH may be associated with the severity of Covid-19 disease. High LDH levels is considered in correlation with lung damage. In line with the previous studies, in our study in the non-survivor group the LDH levels were statistically significantly higher compared to survivor group (p = 0.019).

Pre-existing health conditions were determined as indicators of poor prognosis. According to the current information, the mortality rate was significantly higher among the elderly with HT, DM, CAD and malignancy.[11,12] A critical course of the disease was observed more commonly in antihypertensive drug receivers. In recently published studies, it has been reported that the administration of angiotensin converting enzyme inhibitors and angiotensin II receptor blocker increased ACE2 receptor expression and the disease progressed severely.[11,13] Similarly, in our study, the number of hypertensive patients was high (n = 100). Besides, we observed that the mortality rate was not statistically significantly high in patients with comorbities but the number of hypertensive patients was very high in the non-survivor group (n = 79).

Chest CT imaging has been widely used in the diagnosis of the Covid-19 pneumonia. On the CT, the diagnosis of Covid-19 pneumonia was generally made upon the appearance of ground-glass opacities.[14] In our study, the mortality of the patients who have bilaterally infiltrated pneumonia was high but CT imaging was not found as a statistically significant predictor for the mortality.

Studies which discuss mortality rates of Covid-19 patients aged 80 years and older are even more rare.[15] Based on current data, the mean for the case fatality rate for adults aged under 60 is estimated to be less than 0.2%, while for those aged over 80 this rate is 9.3%.[11] In a recent study, it was stated that the fatality rate for Covid-19 patients on ventilators aged 80 and older was 90%.[4] Similarly, during an influenza pandemic being 85 years and older was an exclusion criterion for ventilation.[16] Clarfield M et al. in their study concluded that for care of older persons during a pandemic, alternative treatment methods should be considered than mechanic ventilator therapy as this could not prevent mortality.[5] In our study, due to rapidly created new Covid-19 intensive care units and following ethical concerns no selection criteria (as old age or any comorbidity) was applied and all conventional treatments were applied to our patients. Consequently, a significant data about Covid-19 patients aged 80 years and older who received intensive care treatment was collected. Accordingly, in our study, ICU mortality rate was found 80.5% and only 5 patients who received IMV therapy could survive. In the review of Cavayas et al., where early experience with critically ill patients with Covid-19 in Montreal at Sacre-Coeur de Montreal Hospital was investigated: it was shown that mortality was 25, and 21% in the IMV patients. It was also stated that mortality rate was 82% in patients older than 80 years old.[17] The application of HFNC provides a better oxygenation by heating and moistening the oxygen with high flow. HFNC has lower transpulmonary pressures compared to IMV and causes less lung damage and it is a very important feature especially for elderly patients whose frailty is high.[18] In our study, it was found that the mortality rate was lower in patients who underwent HFNC and/or NIMV treatments compared to patients who had IMV.

In the study of Nabors C et al. patients 80 years or older requiring ICU care had a high mortality (57%) and mortality rate among patients who developed a need for RRT was %100. In this study it was also revealed that, 21% of the patients was received convalescent plasma and the mortality rate was found as 47%.[3] In our study, among the 10 patients who had HDF only 4 patients survived. Besides, among the 5 patients who received plasma therapy only 2 of them survived.

Clinical studies although limited in sample size and heterogeneity of the experimental design, show that the use of anti-IL-6 mAbs in Covid-19 patients has some positive effect on the improvement.[19] Those experimental therapies in elderly Covid-19 patients may ultimately worsen the outcomes.[3] We used anti-cytokine (tocilizumab) in the treatment of 3 patients and among them only 1 patient survived.

Our study has certain limitations. Firstly, our study is a retrospective study and it contains only the patients of a single hospital. Another limitation is that full medical history of the patients could not be exactly accessed due to the lack of communication caused by the pandemic conditions as well as the cognitive deficiency because of the old age of patients and their relatives. Finally, the number of patients received convalescent plasma and anti-cytokine treatments was very low.

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