Table 2. Comparisons by cause of death among patients <20 years of age, Japan, May 2009–March 2010*.
| Characteristic | Unexpected CPA, n = 15† | Encephalopathy, n = 15† | Respiratory failure, n = 6† | p value |
|---|---|---|---|---|
| Median age, mo (range) | 43 (7–164) | 62 (17–200) | 78 (45–206) | 0.053 |
| Male sex, no. (%) patients |
9 (60) |
10 (67) |
2 (33) |
NS |
| Preexisting condition, no. (%) patients | ||||
| Any | 1 (7)‡ | 5 (33) | 5 (83)§ | <0.05 |
| Respiratory disorders | 0‡ | 3 (20) | 4 (67)§ | <0.05 |
| Neurologic disorders | 1 (7)‡ | 3 (20) | 5 (83)§ | <0.05 |
| Previous history of febrile seizures |
2 (13) |
3 (20) |
0 |
NS |
| Days from influenza onset to life-threatening event (range) | 1 (0–9) | 1 (0–2) | 1 (0–9) | NS |
| Days from influenza onset to death (range) |
1 (0–9) |
3 (0–45) |
1.5 (1–11) |
<0.05¶ |
| Clinical signs, no. (%) patients | ||||
| Cough | 5 (36), n = 14 | 11 (73) | 3 (50) | NS |
| Rhinorrhea | 4 (29), n = 14 | 7 (47) | 1 (17) | NS |
| Tachypnea or dyspnea | 1 (7), n = 14 | 4 (27) | 3 (50) | NS |
| Wheezing | 1 (7), n = 14 | 1 (7) | 2 (33) | NS |
| Vomiting or diarrhea |
2 (14), n = 14 |
5 (33) |
0 |
NS |
| Drugs received before life-threatening event, no. (%) patients | ||||
| Oseltamivir | 7 (47) | 6 (40) | 5 (83) | NS |
| Zanamivir | 1 (7) | 2 (13) | 2 (33) | NS |
| Acetaminophen |
3 (30), n = 10 |
7 (50), n = 14 |
2 (40), n = 5 |
NS |
| Leukocyte count, cells/μL, median (range) | 6,600 (4,200–11,100), n = 11 | 9,350 (3,100–28,730), n = 14 | 10,500 (8,650–101,200), n = 5 | NS |
| Platelet count, × 104 cells/μL, median (range) | 20.5 (11.4–45.8), n = 11 | 15.1 (6.2–32.2) | 11.5 (8.4–49.0), n = 5 | NS |
| Aspartate aminotransferase, IU/L, median (range) | 248 (55–1,981), n = 12 | 233 (18–1,760) | 52 (34–73), n = 4 | 0.060 |
| Alanine transaminase, IU/L, median (range) | 157 (32–845), n = 12 | 70 (9–1,058) | 26 (16–57), n = 4 | <0.05¶ |
| Lactate dehydrogenase, IU/L, median (range) | 704 (215–4,801), n = 12 | 899 (160–3,610), n = 14 | 535 (222–1,022), n = 4 | NS |
| Creatine kinase, IU/L, median (range) | 302 (136–10,612), n = 12 | 190 (63–1,026), n = 14 | 64 (16–211), n = 4 | <0.01# |
| Blood urea nitrogen, mg/dL, median (range) | 11.2 (7.0–31.0), n = 12 | 22.5 (11.7–40.0), n = 14 | 10.0 (4.0–15.0), n = 4 | <0.01** |
| Creatinine, mg/dL, median (range) | 0.65 (0.17–1.40), n = 12 | 1.01 (0.62–1.39) | 0.25 (0.08–1.00), n = 4 | <0.05** |
*CPA, cardiopulmonary arrest; NS, not significant. †n is for all values unless indicated otherwise. ‡Percentage significantly lower than for the other groups. §Percentage significantly higher than for the other groups. ¶p<0.05 unexpected CPA vs. encephalopathy. #p<0.05 unexpected CPA vs. respiratory failure. **p<0.01 unexpected CPA vs. encephalopathy; p<0.05 respiratory failure vs. encephalopathy.