Israel Medical Association Journal

Background: Timely extubation is important integral part of the treatment of intensive care patients.

Objective: To evaluate hand grip strength using a Jamar Hydraulic Hand Dynamometer as a predictor of success or failure in weaning from ventilation.

Methods: This prospective study included 104 patients (62 males, 42 females) who were ventilated in the general intensive care unit (ICU), and who were alert and cooperating. They undertook a hand grip strength test using the Jamar dynamometer, within hours of extubation. Patients needing resuscitation within 72 hours were defined as failure.

Results: Success rate in weaning from ventilation was 85.6%, and 89 patients successfully weaned from ventilation. Those who were successfully weaned had stronger hand grip than those who failed. Males had a mean kg-strength 31.3 ± 11.5 vs. 23.6 ± 10.3 (P = 0.033), and in females mean kg-strength 23.14 ± 16.39 vs. 11.67 ± 10.33 (P = 0.031). A threshold value (22.5 kg-strength) was found to predict success for weaning from ventilation in the male group, with a sensitivity of 70.0% and a specificity of 62.5%. In the female group, the duration of the ventilation alone was statistically significant (P = 0.049).

Conclusions: There was a connection between hand strength and success in weaning from ventilation. A threshold value can help the medical staff to decide on extubation. Hand grip strength can predict successful weaning from ventilation and does not require high skills, time, a large staff, or high financial cost, and it does not endanger the patient.

Background: Enteral nutrition in the critically ill patient is often complicated by gastrointestinal intolerance, manifested by a large gastric residual volume. The frequency of GRV[1] assessment and the intolerant level above which feeding is stopped is controversial.

Objectives: To evaluate a novel approach to EN[2] by allowing high GRV and once-daily assessment that was correlated with the paracetamol absorption test.

Methods: We conducted a pilot prospective study in an 18 bed general intensive care unit. The study group comprised 52 consecutive critically ill mechanically ventilated patients. Enteral nutrition was started at full delivery rate. Once-daily assessment of GRV with three consecutively repeated threshold volumes of 500 ml was performed before stopping EN. The paracetamol absorption test was performed and correlated to GRV. Patients were divided into two groups: low GRV (< 500 ml), and high GRV (at least one measurement of GRV > 500 ml). Clinical outcome included maximal calories delivered, incidence of pneumonia, ICU[3] length of stay, and ICU and hospital mortality.

Results: There were 4 patients (9.5%) with ventilator-associated pneumonia in the low GRV group and 3 (30%) in the high GRV group (P = 0.12). GRV was inversely correlated to paracetamol absorption; however, neither GRV nor paracetamol absorption was associated with the development of pneumonia. Both groups had similar ICU length of stay (11.0 ± 8.2 vs. 13.8 ± 14.4 days, P = 0.41), and similar ICU (21% vs. 40%, P = 0.24) and hospital mortality (35% vs. 40%, P = 1.0).

Conclusions: In critically ill mechanically ventilated patients, allowing larger gastric residual volumes, measured once daily, enables enteral feeding with fewer interruptions which results in high calorie intake without significant complications or side effects.

Objectives: To minimize ventilatory limitation during training of patients with severe COPD[1] by applying bi-level positive pressure ventilation during training in order to augment training intensity (and effect).

Methods: The study group comprised 19 patients (18 males, 1 female) with a mean age of 64 ± 9 years. Mean forced expiratory volume in 1 second was 32 ± 4% of predicted, and all were ventilatory-limited (exercise breathing reserve 3 ± 9 L/min, normal >15 L/min). The patients were randomized: 9 were assigned to training with BiPAP[2] and 10 to standard training. All were trained on a treadmill for 2 months, twice a week, 45 minutes each time, at maximal tolerated load. Incremental maximal unsupported exercise test was performed before and at the end of the training period.

Results: BiPAP resulted in an increment of 94 ± 53% in training speed during these 2 months, as compared to 41 ± 19% increment in the control group (P < 0.005). Training with BiPAP yielded an average increase in maximal oxygen uptake of 23 ± 16% (P < 0.005), anaerobic threshold of 11 ± 12% (P < 0.05) and peak O₂ pulse of 20 ± 19% (P < 0.05), while peak exercise lactate concentration was not higher after training. Interestingly, in the BiPAP group, peak exercise ventilation was also 17 ± 20% higher after training (P < 0.05). Furthermore, contrary to our expectation, at any given work rate, ventilation (and tidal volume) in the BiPAP group was higher in the post-training test as compared to the pre-training test, and the end tidal partial pressure of CO₂ at 55 watts was lower, 40 ± 4 and 38 ± 4 mmHg respectively (P < 0.05). No improvement in exercise capacity was observed after this short training period in the control group.

Conclusion: Pressure-supported ventilation during training is feasible in patients with severe COPD and it augments the training effect. The improved exercise tolerance was associated with higher ventilatory response and therefore lower P_ETCO₂[3] at equal work rates after training.

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[1] COPD = chronic obstructive pulmonary disease

[2] BiPAP = bi-level positive pressure ventilation

[3] P_ETCO₂ = end tidal partial pressure of CO₂