Postoperative ICU Patients Research Articles

Pattern of 72-hour intragastric acidity in a homogeneous group of intensive care unit patients.

To gain insight into the variation over time of gastric acidity in postoperative ICU patients, intragastric pH was prospectively studied in patients undergoing elective abdominal aortic reconstructive surgery during a 72-hr intra- and postoperative period. Intragastric pH was monitored continuously in 14 patients with combined glass electrodes. During the day of surgery (day 1), the median 24-hr pH for all patients was 6.25 (5.8-7.0, IQR). However, three of the 14 studied patients had a median 24-hr pH of 1.8. The median 24-hr pH throughout day 2 for all was 2.45 (1.6-4.7, P = 0.001). The median 24-hr pH on day 3 was 1.6 (1.5-2.1, P = 0.001). Median 8-hr pH values demonstrate a remarkable interpatient and intraindividual variation in the course of the postoperative period. A progressive lowering of the intragastric pH was observed in the first 40 hr. From the 40- to 48-hr interval until the end of the study, no further significant decrease was found. The intragastric pH was above 4, 74% of the time during day 1, 39% during day 2 (P = 0.006) and 16% during day 3 (P = 0.003). Percentage of time above 4 on day 2 was significantly higher than on day 3 (P = 0.04). In conclusion, since gastric acid and pepsin seem to play a role in stress ulceration, this study suggests some patients are at risk of stress ulceration from the beginning of surgery, but most patients become at risk of stress ulceration in the course of the postoperative period.

Preoperative intensive care unit consultations

To determine if a structured preoperative ICU consultation would correctly assign patients to preoperative invasive monitoring, postoperative ICU care, or recovery room care, and to compare morbidity, mortality, and resource utilization among all groups. Prospective, observational study. A university hospital. A total of 475 patients who were referred preoperatively by surgeons for ICU consultation and were evaluated by ICU physicians. Patients assessed to have clinical evidence of cardiovascular compromise were admitted preoperatively to the ICU for invasive hemodynamic monitoring and optimization. Patients without such evidence, but who were to undergo major operations or had anticipated major fluid replacement were independently selected for invasive monitoring by anesthesiologists. Patients who developed physiologic instability or became unstable due to hemorrhage also underwent invasive monitoring. Nonmonitored patients who remained stable were given postoperative ICU care or went to the recovery room based on an assessment by the surgeon and anesthesiologist at the end of the operation. Of 8,916 elective surgical cases, ICU physicians were consulted in 475 (5.3%) patients preoperatively. Sixty-seven patients were admitted preoperatively to the ICU for invasive hemodynamic monitoring and optimization; 60 patients had surgery (0.7% of elective cases, 12.6% of ICU consultations). Patients selected for ICU preoperative monitoring were older than non-monitored patients and had higher numbers of cardiovascular and total risk factors than any other group. They had higher Acute Physiology and Chronic Health Evaluation (APACHE II) scores, higher Therapeutic Intervention Scoring System (TISS) points, a higher number of complications, and longer ICU stays than non-monitored postoperative ICU patients. In addition, they had a higher number of complications than nonmonitored recovery room patients. APACHE II scores, TISS points, number of complications, and ICU days in the preoperative ICU admission group were not increased when compared with all other monitored patients. Neither hospital days nor total hospital charges were increased when compared with the other elective ICU patients. Patients selected for ICU preoperative monitoring who underwent surgery had an 11.7% mortality rate and accounted for four of five cardiovascular-related deaths. A small number of high-risk patients can be selected for preoperative monitoring on the basis of clinical assessment without increasing ICU stay or hospital bills. A structured preoperative consultation correctly identifies those patients who need monitoring and ICU care, but does not overutilize scarce and expensive ICU beds.

Cardiovascular parameters and scoring systems in the evaluation of response to therapy in sepsis and septic shock

In 47 medical and postoperative ICU patients with 57 episodes of sepsis and septic shock, cardiovascular parameters including systemic vascular resistance (SVR), cardiac index (CI), stroke volume index (SVI), left ventricular stroke work index (LVSWI) as well as six scoring systems (APACHE II, Elebute, Goris, HIS, SAPS and SSS) were studied regarding their usefulness in the assessment of disease progression and evaluation of response to supplemental sepsis therapy (immunoglobulins, plasmapheresis). Among the hemodynamic parameters, only a prompt SVR improvement significantly discriminated between ultimate survivors and nonsurvivors. Thus, an increase in SVR (greater than 160 dyn*cm-5*sec, within days 0 to 4, persisting for greater than 24 hours) can serve as a prognostically validated "response" criterion (responders/non-responders: 26/31; mortality: 27% vs. 77%). Non-invasively, the APACHE II score was best suited (specificity: 88%, sensitivity: 67%) to classify hemodynamically defined responders to supplemental sepsis treatment (score-reduction greater than or equal to 4 on day 4 after onset of therapy).

Hypomagnesemia in patients in postoperative intensive care.

In order to study the clinical consequences of postoperative hypomagnesemia, the serum magnesium (Mg) concentration was measured in samples of blood collected from 193 patients admitted to two postoperative ICUs. On admission to the ICU, 117 patients (61 percent) had hypomagnesemia (serum Mg less than 1.5 mEq/dl), 66 patients (34 percent) had normomagnesemia (1.5 to 2.0 mEq/dl), and ten patients (5 percent) had hypermagnesemia (greater than 2.0 mEq/dl). There were no correlations between the severity of illness score (r = 0.145) or the degree of hypoproteinemia (r = 0.01) and the postoperative serum Mg level. Patients with severe hypomagnesemia (serum Mg less than or equal to 1.0 mEq/dl) experienced hypokalemia more often (p less than 0.02) than the others in the study. Furthermore, those with severe hypomagnesemia had a higher mortality rate (7/17 or 41 percent) than the remainder of the population studied (22/176 or 13 percent) (p less than 0.02). Those with severe hypomagnesemia had received aminoglycosides more often (p less than 0.001) than those with normal serum Mg concentrations. The serum Mg level was not a sensitive (68 percent) or specific (37 percent) predictor of survival. Our conclusions were as follows: (1) hypomagnesemia is common in postoperative ICU patients; and (2) patients in the postoperative ICU who have severe hypomagnesemia have a higher mortality and more hypokalemia than similarly ill patients with normomagnesemia. Because of the association between aminoglycoside therapy and severe hypomagnesemia, we recommend measurement of this variable in those patients receiving aminoglycosides. Furthermore, Mg replacement therapy is recommended for those patients with serum Mg values of 1 mEq/dl or less.

Use of constant-infusion verapamil for the treatment of postoperative supraventricular tachycardia.

The effects of constant-infusion verapamil were studied in ten postoperative ICU patients who developed supraventricular tachycardia (atrial fibrillation) with rapid ventricular response rates. A 5-mg iv bolus dose of verapamil was followed by a 5-mg/h infusion that continued for 8 h. Ventricular rates were significantly (p less than .005) reduced from a pretreatment mean of 156 +/- 14 (SD) to 104 +/- 9 beat/min on constant-infusion therapy. This therapy was well tolerated without observed side-effects. Moreover, constant-infusion verapamil might avoid the hypotension and wide range of ventricular rates frequently encountered with repeated bolus doses of verapamil.